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1

Rational Device Design for Highly Efficient Organic Photovoltaic Solar Cells.  

E-Print Network (OSTI)

??Abundant, scalable, environmentally-friendly organic photovoltaic (OPV) technology is increasingly promising in recent years. The power conversion efficiency (PCE) of OPVs has been raised to around… (more)

Yang, Bin

2013-01-01T23:59:59.000Z

2

The Importance of Domain Size and Purity in High-Efficiency Organic Solar  

NLE Websites -- All DOE Office Websites (Extended Search)

The Importance of Domain Size and Purity in High-Efficiency Organic Solar Cells Print The Importance of Domain Size and Purity in High-Efficiency Organic Solar Cells Print The efficiency of polymer/organic photovoltaic cells hinges on excitons-electron/hole pairs energized by sunlight-getting to the interfaces of donor and acceptor domains quickly, before recombining. At the interfaces, they become free charges that must then reach device electrodes. With the discovery of mixed domains of donor and acceptor molecules, many have pictured the excitons' journey as easy (interfaces are everywhere) but the charges' journey as precarious (interfaces are everywhere). Instead, using a combination of x-ray scattering and microscopy techniques, researchers have found that excitons may actually not fare so well in mixed domains but need access to pure aggregates to efficiently convert into charges. The smaller the aggregates, the better, allowing increased interfacial area and dramatic increases in device performance.

3

The Importance of Domain Size and Purity in High-Efficiency Organic Solar  

NLE Websites -- All DOE Office Websites (Extended Search)

The Importance of Domain Size and Purity in High-Efficiency Organic Solar Cells Print The Importance of Domain Size and Purity in High-Efficiency Organic Solar Cells Print The efficiency of polymer/organic photovoltaic cells hinges on excitons-electron/hole pairs energized by sunlight-getting to the interfaces of donor and acceptor domains quickly, before recombining. At the interfaces, they become free charges that must then reach device electrodes. With the discovery of mixed domains of donor and acceptor molecules, many have pictured the excitons' journey as easy (interfaces are everywhere) but the charges' journey as precarious (interfaces are everywhere). Instead, using a combination of x-ray scattering and microscopy techniques, researchers have found that excitons may actually not fare so well in mixed domains but need access to pure aggregates to efficiently convert into charges. The smaller the aggregates, the better, allowing increased interfacial area and dramatic increases in device performance.

4

The Importance of Domain Size and Purity in High-Efficiency Organic Solar  

NLE Websites -- All DOE Office Websites (Extended Search)

The Importance of Domain Size and Purity in High-Efficiency Organic Solar Cells Print The Importance of Domain Size and Purity in High-Efficiency Organic Solar Cells Print The efficiency of polymer/organic photovoltaic cells hinges on excitons-electron/hole pairs energized by sunlight-getting to the interfaces of donor and acceptor domains quickly, before recombining. At the interfaces, they become free charges that must then reach device electrodes. With the discovery of mixed domains of donor and acceptor molecules, many have pictured the excitons' journey as easy (interfaces are everywhere) but the charges' journey as precarious (interfaces are everywhere). Instead, using a combination of x-ray scattering and microscopy techniques, researchers have found that excitons may actually not fare so well in mixed domains but need access to pure aggregates to efficiently convert into charges. The smaller the aggregates, the better, allowing increased interfacial area and dramatic increases in device performance.

5

The Importance of Domain Size and Purity in High-Efficiency Organic Solar  

NLE Websites -- All DOE Office Websites (Extended Search)

The Importance of Domain Size The Importance of Domain Size and Purity in High-Efficiency Organic Solar Cells The Importance of Domain Size and Purity in High-Efficiency Organic Solar Cells Print Wednesday, 27 March 2013 00:00 The efficiency of polymer/organic photovoltaic cells hinges on excitons-electron/hole pairs energized by sunlight-getting to the interfaces of donor and acceptor domains quickly, before recombining. At the interfaces, they become free charges that must then reach device electrodes. With the discovery of mixed domains of donor and acceptor molecules, many have pictured the excitons' journey as easy (interfaces are everywhere) but the charges' journey as precarious (interfaces are everywhere). Instead, using a combination of x-ray scattering and microscopy techniques, researchers have found that excitons may actually not fare so well in mixed domains but need access to pure aggregates to efficiently convert into charges. The smaller the aggregates, the better, allowing increased interfacial area and dramatic increases in device performance.

6

Low temperature metal-organic chemical vapor deposition growth processes for high-efficiency solar cells  

DOE Green Energy (OSTI)

This report describes the results of a program to develop a more complete understanding of the physical and chemical processes involved in low-temperature growth of III-V compounds by metal-organic chemical vapor deposition (MOCVD) and to develop a low-temperature process that is suitable for the growth of high-efficiency solar cells. The program was structured to develop a better understanding of the chemical reactions involved in MOCVD growth, to develop a model of the processes occurring in the gas phase, to understand the physical kinetics and reactions operative on the surface of the growing crystal, and to develop an understanding of the means by which these processes may be altered to reduce the temperature of growth and the utilization of toxic hydrides. The basic approach was to develop the required information about the chemical and physical kinetics operative in the gas phase and on the surface by the direct physical measurement of the processes whenever possible. The program included five tasks: (1) MOCVD growth process characterization, (2) photoenhanced MOCVD studies, (3) materials characterization, (4) device fabrication and characterization, and (5) photovoltaic training. Most of the goals of the program were met and significant progress was made in defining an approach that would allow both high throughput and high uniformity growth of compound semiconductors at low temperatures. The technical activity was focused on determining the rates of thermal decomposition of trimethyl gallium, exploring alternate arsenic sources for use MOCVD, and empirical studies of atomic layer epitaxy as an approach.

Dapkus, P.D. (University of Southern California, Los Angeles, CA (United States))

1993-02-01T23:59:59.000Z

7

High efficiency solar heater  

SciTech Connect

This patent describes a solar oven comprising canted side-walls defining a heating chamber of inverted pyramidal configuration having a rectangular upper aperture for admitting solar radiation into the chamber, and a closed bottom, the side walls having four blackened non-reflective interior surfaces and translucent means closing the upper aperture for containing heated air with the chamber. The four interior surfaces are exposed to radiation entering the chamber through the translucent means. A frusto-pyramidal reflector is removably mounted externally of the heating chamber and including four reflector surfaces diverging from each other at a somewhat greater angle than the interior surfaces such that light falling onto the external reflector substantially normally to the translucent means is reflected onto an opposite one of the interior surfaces substantially at right angles thereto; and temperature responsive means arranged for opening a vent into the chamber in response to temperature rising in the chamber beyond a predetermined level. The temperature responsive means comprises spring means retained in a compressed state by structural means selected to lose structural integrity near the predetermined level. The spring means is released upon the structural means losing structural integrity near the predetermined level and failing under load imposed by the spring means, whereby the spring means is free to operate to open the vent.

Varney, J.A.; Varney, F.M.

1987-01-20T23:59:59.000Z

8

High Efficiency Organic Solar Cells: December 16, 2009 - February 2, 2011  

DOE Green Energy (OSTI)

Details on the development of novel organic solar cells incorporating Trimetasphere based acceptors are presented including: baseline performance for Lu-PCBEH acceptor blended with P3HT demonstrated at 4.89% PCE exceeding the 4.5% PCE goal; an increase of over 250mV in Voc was demonstrated for Lu-PCBEH blended with low band gap polymers compared to a comparable C60-PCBM device. The actual Voc was certified at 260mV higher for a low band gap polymer device using the Lu-PCBEH acceptor; and the majority of the effort was focused on development of a device with over 7% PCE. While low current and fill factors suppressed overall device performance for the low band gap polymers tested, significant discoveries were made that point the way for future development of these novel acceptor materials.

Walker, K.; Joslin, S.

2011-05-01T23:59:59.000Z

9

High Efficiency Solar Integrated Roof Membrane Product  

SciTech Connect

This project was designed to address the Solar Energy Technology Program objective, to develop new methods to integrate photovoltaic (PV) cells or modules within a building-integrated photovoltaic (BIPV) application that will result in lower installed cost as well as higher efficiencies of the encapsulated/embedded PV module. The technology assessment and development focused on the evaluation and identification of manufacturing technologies and equipment capable of producing such low-cost, high-efficiency, flexible BIPV solar cells on single-ply roofing membranes.

Partyka, Eric; Shenoy, Anil

2013-05-15T23:59:59.000Z

10

High-efficiency concentrator silicon solar cells  

DOE Green Energy (OSTI)

This report presents results from extensive process development in high-efficiency Si solar cells. An advanced design for a 1.56-cm{sup 2} cell with front grids achieved 26% efficiency at 90 suns. This is especially significant since this cell does not require a prismatic cover glass. New designs for simplified backside-contact solar cells were advanced from a status of near-nonfunctionality to demonstrated 21--22% for one-sun cells in sizes up to 37.5 cm{sup 2}. An efficiency of 26% was achieved for similar 0.64-cm{sup 2} concentrator cells at 150 suns. More fundamental work on dopant-diffused regions is also presented here. The recombination vs. various process and physical parameters was studied in detail for boron and phosphorous diffusions. Emitter-design studies based solidly upon these new data indicate the performance vs design parameters for a variety of the cases of most interest to solar cell designers. Extractions of p-type bandgap narrowing and the surface recombination for p- and n-type regions from these studies have a generality that extends beyond solar cells into basic device modeling. 68 refs., 50 figs.

Sinton, R.A.; Cuevas, A.; King, R.R.; Swanson, R.M. (Stanford Univ., CA (USA). Solid-State Electronics Lab.)

1990-11-01T23:59:59.000Z

11

High efficiency, radiation-hard solar cells  

DOE Green Energy (OSTI)

The direct gap of the In{sub 1-x}Ga{sub x}N alloy system extends continuously from InN (0.7 eV, in the near IR) to GaN (3.4 eV, in the mid-ultraviolet). This opens the intriguing possibility of using this single ternary alloy system in single or multi-junction (MJ) solar cells of the type used for space-based surveillance satellites. To evaluate the suitability of In{sub 1-x}Ga{sub x}N as a material for space applications, high quality thin films were grown with molecular beam epitaxy and extensive damage testing with electron, proton, and alpha particle radiation was performed. Using the room temperature photoluminescence intensity as a indirect measure of minority carrier lifetime, it is shown that In{sub 1-x}Ga{sub x}N retains its optoelectronic properties at radiation damage doses at least 2 orders of magnitude higher than the damage thresholds of the materials (GaAs and GaInP) currently used in high efficiency MJ cells. This indicates that the In{sub 1-x}Ga{sub x}N is well-suited for the future development of ultra radiation-hard optoelectronics. Critical issues affecting development of solar cells using this material system were addressed. The presence of an electron-rich surface layer in InN and In{sub 1-x}Ga{sub x}N (0 < x < 0.63) was investigated; it was shown that this is a less significant effect at large x. Evidence of p-type activity below the surface in Mg-doped InN was obtained; this is a significant step toward achieving photovoltaic action and, ultimately, a solar cell using this material.

Ager III, J.W.; Walukiewicz, W.

2004-10-22T23:59:59.000Z

12

The Importance of Domain Size and Purity in High-Efficiency Organic...  

NLE Websites -- All DOE Office Websites (Extended Search)

The Importance of Domain Size and Purity in High-Efficiency Organic Solar Cells Print The efficiency of polymerorganic photovoltaic cells hinges on excitons-electronhole pairs...

13

Low Cost, High Efficiency Tandem Silicon Solar Cells and LEDs  

Wladek Walukiewicz, Joel Ager, and Kin Man Yu of Berkeley Lab have developed high-efficiency solar cells that leverage the well-established design and ...

14

High-efficiency solar cell and method for fabrication  

DOE Patents (OSTI)

A high-efficiency 3- or 4-junction solar cell is disclosed with a theoretical AM0 energy conversion efficiency of about 40%. The solar cell includes p-n junctions formed from indium gallium arsenide nitride (InGaAsN), gallium arsenide (GaAs) and indium gallium aluminum phosphide (InGaAlP) separated by n-p tunnel junctions. An optional germanium (Ge) p-n junction can be formed in the substrate upon which the other p-n junctions are grown. The bandgap energies for each p-n junction are tailored to provide substantially equal short-circuit currents for each p-n junction, thereby eliminating current bottlenecks and improving the overall energy conversion efficiency of the solar cell. Additionally, the use of an InGaAsN p-n junction overcomes super-bandgap energy losses that are present in conventional multi-junction solar cells. A method is also disclosed for fabricating the high-efficiency 3- or 4-junction solar cell by metal-organic chemical vapor deposition (MOCVD).

Hou, Hong Q. (Albuquerque, NM); Reinhardt, Kitt C. (Albuquerque, NM)

1999-01-01T23:59:59.000Z

15

High-efficiency solar cell and method for fabrication  

DOE Patents (OSTI)

A high-efficiency 3- or 4-junction solar cell is disclosed with a theoretical AM0 energy conversion efficiency of about 40%. The solar cell includes p-n junctions formed from indium gallium arsenide nitride (InGaAsN), gallium arsenide (GaAs) and indium gallium aluminum phosphide (InGaAlP) separated by n-p tunnel junctions. An optional germanium (Ge) p-n junction can be formed in the substrate upon which the other p-n junctions are grown. The bandgap energies for each p-n junction are tailored to provide substantially equal short-circuit currents for each p-n junction, thereby eliminating current bottlenecks and improving the overall energy conversion efficiency of the solar cell. Additionally, the use of an InGaAsN p-n junction overcomes super-bandgap energy losses that are present in conventional multi-junction solar cells. A method is also disclosed for fabricating the high-efficiency 3- or 4-junction solar cell by metal-organic chemical vapor deposition (MOCVD). 4 figs.

Hou, H.Q.; Reinhardt, K.C.

1999-08-31T23:59:59.000Z

16

High efficiency, radiation-hard solar cells  

E-Print Network (OSTI)

x Ga x N alloys: a full-solar-spectrum photovoltaic materialto the useful part of the solar spectrum. In fact, current

Ager III, J.W.; Walukiewicz, W.

2004-01-01T23:59:59.000Z

17

Low temperature metal-organic chemical vapor deposition growth processes for high-efficiency solar cells. Final technical report, 1 September 1985--30 November 1989  

DOE Green Energy (OSTI)

This report describes the results of a program to develop a more complete understanding of the physical and chemical processes involved in low-temperature growth of III-V compounds by metal-organic chemical vapor deposition (MOCVD) and to develop a low-temperature process that is suitable for the growth of high-efficiency solar cells. The program was structured to develop a better understanding of the chemical reactions involved in MOCVD growth, to develop a model of the processes occurring in the gas phase, to understand the physical kinetics and reactions operative on the surface of the growing crystal, and to develop an understanding of the means by which these processes may be altered to reduce the temperature of growth and the utilization of toxic hydrides. The basic approach was to develop the required information about the chemical and physical kinetics operative in the gas phase and on the surface by the direct physical measurement of the processes whenever possible. The program included five tasks: (1) MOCVD growth process characterization, (2) photoenhanced MOCVD studies, (3) materials characterization, (4) device fabrication and characterization, and (5) photovoltaic training. Most of the goals of the program were met and significant progress was made in defining an approach that would allow both high throughput and high uniformity growth of compound semiconductors at low temperatures. The technical activity was focused on determining the rates of thermal decomposition of trimethyl gallium, exploring alternate arsenic sources for use MOCVD, and empirical studies of atomic layer epitaxy as an approach.

Dapkus, P.D. [University of Southern California, Los Angeles, CA (United States)

1993-02-01T23:59:59.000Z

18

SOLAR POWERING OF HIGH EFFICIENCY ABSORPTION CHILLER  

SciTech Connect

This is the Final Report for two solar cooling projects under this Cooperative Agreement. The first solar cooling project is a roof-integrated solar cooling and heating system, called the Power Roof{trademark}, which began operation in Raleigh, North Carolina in late July 2002. This system provides 176 kW (50 ton) of solar-driven space cooling using a unique nonimaging concentrating solar collector. The measured performance of the system during its first months of operation is reported here, along with a description of the design and operation of this system. The second solar cooling system, with a 20-ton capacity, is being retrofit to a commercial office building in Charleston, South Carolina but has not yet been completed.

Randy C. Gee

2004-11-15T23:59:59.000Z

19

Highly Efficient Multigap Solar Cell Materials  

Scientists at Berkeley Lab have invented multiband gap semiconducting materials for developing solar cells that could achieve power conversion efficiencies of 50 percent or higher.

20

High Efficiency Solar Power via Separated Photo and Voltaic Pathways  

DOE Green Energy (OSTI)

This project demonstrates a novel nanostructured solar cell architecture capable of achieving high efficiency levels that is relatively simple and inexpensive to manufacture. The high efficiency will be achieved by the novel structure that separates the path of the photons from the path of the generated charge carriers. In this way, the photon path can be long for maximum light absorption, while the path for carriers can be short for maximum electronic energy harvesting. The combination of maximum light absorption coupled with maximum carrier harvesting is the basis for the expected high efficiency. The project will develop high efficiency solar cell prototypes utilizing this unique nanostructured architecture. The project addresses the fundamental limitation inherent in all current solar cell designs, and which opens a pathway to development for high efficiency solar cells at low cost. Realizing this goal will result in a levelized cost of electricity in the range of 10˘/kWh, which would achieve the long-sought goal of making photovoltaic electricity cost competitive with fossil-fuel generated electricity without any governmental subsidies. This breakthrough would spur the already rapid growth in the photovoltaic industry to an explosive pace, with significant, widespread benefit to the national economy and the nation’s energy security. The initial target of the program is to develop single-junction solar cells using ultrathin amorphous silicon with the performance approaching that of single crystal silicon cells.

Michael J. Naughton

2009-02-17T23:59:59.000Z

Note: This page contains sample records for the topic "high-efficiency organic solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

High-Efficiency Solar Cell Concepts: Physics, Materials, and Devices  

DOE Green Energy (OSTI)

Over the past three decades, significant progress has been made in the area of high-efficiency multijunction solar cells, with the effort primarily directed at current-matched solar cells in tandem. The key materials issues here have been obtaining semiconductors with the required bandgaps for sequential absorption of light in the solar spectrum and that are lattice matched to readily available substrates. The GaInP/GaAs/Ge cell is a striking example of success achieved in this area. Recently, several new approaches for high-efficiency solar cell design have emerged, that involve novel methods for tailoring alloy bandgaps, as well as alternate technologies for hetero-epitaxy of III-V's on Si. The advantages and difficulties expected to be encountered with each approach will be discussed, addressing both the materials issues and device physics whilst contrasting them with other fourth-generation solar cell concepts.

Mascarenhas, A.; Francoeur, S.; Seong, M. J.; Fluegel, B.; Zhang, Y.; Wanlass, M. W.

2005-01-01T23:59:59.000Z

22

Modelling and fabrication of high-efficiency silicon solar cells  

DOE Green Energy (OSTI)

This report covers the research conducted on modelling and development of high-efficiency silicon solar cells during the period May 1989 to August 1990. First, considerable effort was devoted toward developing a ray-tracing program for the photovoltaic community to quantify and optimize surface texturing for solar cells. Second, attempts were made to develop a hydrodynamic model for device simulation. Such a model is somewhat slower than drift-diffusion type models like PC-1D, but it can account for more physical phenomena in the device, such as hot carrier effects, temperature gradients, thermal diffusion, and lattice heat flow. In addition, Fermi-Dirac statistics have been incorporated into the model to deal with heavy doping effects more accurately. Third and final component of the research includes development of silicon cell fabrication capabilities and fabrication of high-efficiency silicon cells. 84 refs., 46 figs., 10 tabs.

Rohatgi, A.; Smith, A.W.; Salami, J. [Georgia Inst. of Tech., Atlanta, GA (United States). School of Electrical Engineering] [Georgia Inst. of Tech., Atlanta, GA (United States). School of Electrical Engineering

1991-10-01T23:59:59.000Z

23

Properties of High Efficiency CIGS Thin Film Solar Cells  

DOE Green Energy (OSTI)

We present experimental results in three areas. Solar cells with an efficiency of 19% have been fabricated with an absorber bandgap in the range of 1.1-1.2 eV. Properties of solar cells fabricated with and without an undoped ZnO layer were compared. The data show that high efficiency cells can be fabricated without using the high-resistivity or undoped ZnO layer. Properties of CIGS solar cells were fabricated from thin absorbers (1 {micro}m) deposited by the three-stage process and simultaneous co-deposition of all the elements. In both cases, solar cells with efficiencies of 16%-17% are obtained.

Ramanathan, K.; Keane, J.; Noufi, R.

2005-02-01T23:59:59.000Z

24

ENGINEERED ELECTRODES AND ELECTRODE-ORGANIC INTERFACES FOR HIGH-EFFICIENCY ORGANIC PHOTOVOLTAICS  

DOE Green Energy (OSTI)

Organic photovoltaic (OPV) cells offer the ultimate promise of low cost, readily manufacturable, and durable solar power. While recent advances have led to cells with impressive performance levels, OPV cells have yet to break the double-digit efficiency barrier. Further gains in efficiency and durability, to that competitive with high-performance inorganic photovoltaics will require breakthroughs in transparent electrode and interfacial materials science and engineering. This project involved an integrated basic research effort carried out by an experienced and highly collaborative interdisciplinary team to address in unconventional ways, critical electrode-interfacial issues underlying OPV performance--controlling band offsets between transparent electrodes and organics, addressing current loss/leakage problems at interfaces, enhancing adhesion, interfacial stability, and device durability while minimizing cost. It synergistically combined materials and interfacial reagent synthesis, nanostructural and photovoltaic characterization, and high level quantum theory. The research foci were: 1) understanding of/development of superior transparent electrode materials and materials morphologies--i.e., better matched electronically and chemically to organic active layers, 2) understanding-based development of inorganic interfacial current-collecting/charge-blocking layers, and 3) understanding-based development of self-assembled adhesion/current-collecting/charge-blocking/cross-linking layers for high-efficiency OPV interfaces. Pursing the goal of developing the fundamental scientific understanding needed to design, fabricate, prototype and ultimately test high-efficiency OPV cells incorporating these new concepts, we achieved a record power conversion efficiency of 5.2% for an organic bulk-heterjunction solar cell.

Tobin J. Marks; R.P.H. Chang; Tom Mason; Ken Poeppelmeier; Arthur J. Freeman

2008-11-13T23:59:59.000Z

25

Processes for producing low cost, high efficiency silicon solar cells  

SciTech Connect

Processes which utilize rapid thermal processing (RTP) are provided for inexpensively producing high efficiency silicon solar cells. The RTP processes preserve minority carrier bulk lifetime .tau. and permit selective adjustment of the depth of the diffused regions, including emitter and back surface field (bsf), within the silicon substrate. Silicon solar cell efficiencies of 16.9% have been achieved. In a first RTP process, an RTP step is utilized to simultaneously diffuse phosphorus and aluminum into the front and back surfaces, respectively, of a silicon substrate. Moreover, an in situ controlled cooling procedure preserves the carrier bulk lifetime .tau. and permits selective adjustment of the depth of the diffused regions. In a second RTP process, both simultaneous diffusion of the phosphorus and aluminum as well as annealing of the front and back contacts are accomplished during the RTP step. In a third RTP process, the RTP step accomplishes simultaneous diffusion of the phosphorus and aluminum, annealing of the contacts, and annealing of a double-layer antireflection/passivation coating SiN/SiO.sub.x.

Rohatgi, Ajeet (Marietta, GA); Chen, Zhizhang (Duluth, GA); Doshi, Parag (Atlanta, GA)

1996-01-01T23:59:59.000Z

26

HIGH EFFICIENCY BIFACIAL BACK SURFACE FIELD SOLAR CELLS  

E-Print Network (OSTI)

The first high efficiency p÷-n-n + bifacial solar cells are presented. Efficiencies of 15.7 % and 13.6 % were measured under front and back air mass one illumination respectively at 28 °C. At 7 air mass one illumination and 28 °C the front efficiency increases to 16.5%. A pilot production of 200 cells was made following a fabrication process as simple as that for conventional back surface field cells. Mean efficiencies of 13.4 % and 10.7 % were obtained under front and back illumination respectively. The production yield is higher than 80%. The advantages that bifacial cells present in some applications, compared with conventional cells, have been pointed out for static [1] and quasi-static [2] concentrating systems, for luminescent concentrators [3] and also for flat panels. A transistor-like structure (n+-p-n +) has already been developed as a bifacial cell [4]. We have also suggested [5] and theoretically analysed [6] the use of a back surface field (BSF) structure (n+-p-p ÷ or p+-n-n +) as a bifacial cell. The purpose here is to demonstrate the feasibility of high efficiency bifacial BSF solar cells. p+-n-n ÷ bifacial cells with a 5 cm 2 area were made on float-zone silicon wafers. The resistivity of the n-type base region was 10 ~2 cm and the thickness was 260 pm. The p ÷ and n + regions were formed by open-tube diffusions using BBr3 and POC13 sources, the resulting sheet resistance being 45- 60 ~2/[:] for the p ÷ layer and 20- 30 ~2/[:] for the n ÷ layer. A TiOx antireflection (AR) coating was spun onto both sides of the cell; Ti-Pd-Ag grids were sputtered and lift-off defined also on both faces. The metallization pattern was designed for the cells to operate inside static compound parabolic mirrors with a concentration factor of 5 and a non-uniform distribution of light intensity on the cell surface. The optimum grid has ten fingers per centimetre (each finger is 50- 70 pm wide) and produces a coverage factor in the illuminated area of about 5.5%.

A. Cuevas; A. Luque; J. Eguren; J. Del Alamo

1980-01-01T23:59:59.000Z

27

Processes for producing low cost, high efficiency silicon solar cells  

DOE Patents (OSTI)

Processes which utilize rapid thermal processing (RTP) are provided for inexpensively producing high efficiency silicon solar cells. The RTP processes preserve minority carrier bulk lifetime .tau. and permit selective adjustment of the depth of the diffused regions, including emitter and back surface field (bsf), within the silicon substrate. In a first RTP process, an RTP step is utilized to simultaneously diffuse phosphorus and aluminum into the front and back surfaces, respectively, of a silicon substrate. Moreover, an in situ controlled cooling procedure preserves the carrier bulk lifetime .tau. and permits selective adjustment of the depth of the diffused regions. In a second RTP process, both simultaneous diffusion of the phosphorus and aluminum as well as annealing of the front and back contacts are accomplished during the RTP step. In a third RTP process, the RTP step accomplishes simultaneous diffusion of the phosphorus and aluminum, annealing of the contacts, and annealing of a double-layer antireflection/passivation coating SiN/SiO.sub.x. In a fourth RTP process, the process of applying front and back contacts is broken up into two separate respective steps, which enhances the efficiency of the cells, at a slight time expense. In a fifth RTP process, a second RTP step is utilized to fire and adhere the screen printed or evaporated contacts to the structure.

Rohatgi, Ajeet (Marietta, GA); Doshi, Parag (Altanta, GA); Tate, John Keith (Lawrenceville, GA); Mejia, Jose (Atlanta, GA); Chen, Zhizhang (Duluth, GA)

1998-06-16T23:59:59.000Z

28

Processes for producing low cost, high efficiency silicon solar cells  

DOE Patents (OSTI)

Processes which utilize rapid thermal processing (RTP) are provided for inexpensively producing high efficiency silicon solar cells. The RTP processes preserve minority carrier bulk lifetime {tau} and permit selective adjustment of the depth of the diffused regions, including emitter and back surface field (bsf), within the silicon substrate. In a first RTP process, an RTP step is utilized to simultaneously diffuse phosphorus and aluminum into the front and back surfaces, respectively, of a silicon substrate. Moreover, an in situ controlled cooling procedure preserves the carrier bulk lifetime {tau} and permits selective adjustment of the depth of the diffused regions. In a second RTP process, both simultaneous diffusion of the phosphorus and aluminum as well as annealing of the front and back contacts are accomplished during the RTP step. In a third RTP process, the RTP step accomplishes simultaneous diffusion of the phosphorus and aluminum, annealing of the contacts, and annealing of a double-layer antireflection/passivation coating SiN/SiO{sub x}. In a fourth RTP process, the process of applying front and back contacts is broken up into two separate respective steps, which enhances the efficiency of the cells, at a slight time expense. In a fifth RTP process, a second RTP step is utilized to fire and adhere the screen printed or evaporated contacts to the structure. 28 figs.

Rohatgi, A.; Doshi, P.; Tate, J.K.; Mejia, J.; Chen, Z.

1998-06-16T23:59:59.000Z

29

Scientists Confirm Robustness of Key Component in Ultra-High-Efficiency Solar Cell (Fact Sheet)  

DOE Green Energy (OSTI)

Scientists developed and tested a new, stable 1-eV metamorphic junction for a high efficiency multijunction III-V solar cell for CPV application.

Not Available

2011-05-01T23:59:59.000Z

30

Integration of High Efficiency Solar Cells on Carriers for Concentrating System Applications .  

E-Print Network (OSTI)

??High efficiency multi-junction (MJ) solar cells were packaged onto receiver systems. The efficiency change of concentrator cells under continuous high intensity illumination was done. Also,… (more)

Chow, Simon Ka Ming

2011-01-01T23:59:59.000Z

31

High Efficiency Organic Light Emitting Devices for Lighting  

SciTech Connect

Incorporate internal scattering layers and microlens arrays in high efficiency OLED to achieve up to 70% EQE.

So, Franky; Tansu, Nelson; Gilchrist, James

2013-06-30T23:59:59.000Z

32

Low Cost, High Efficiency Tandem Silicon Solar Cells and LEDs  

iency solar cells that leverage the well-established design and manufacturing technology of silicon cells while delivering the performance previously achievable only by far more complex and expensive tandem solar cells. 

33

High Efficiency Adsorption Chillers: High Efficiency Adsorption Cooling Using Metal Organic Heat Carriers  

SciTech Connect

BEETIT Project: PNNL is incorporating significant improvements in materials that adsorb liquids or gases to design more efficient adsorption chillers. An adsorption chiller is a type of air conditioner that is powered by heat, solar or waste heat, or combustion of natural gas. Unlike typical chillers, this type has few moving parts and uses almost no electricity to operate. PNNL is designing adsorbent materials at the molecular level with at least 3 times higher refrigerant capacity and up to 20 times faster kinetics than adsorbents used in current chillers. By using the new adsorbent, PNNL is able to create a chiller that is significantly smaller, has twice the energy efficiency, and lower costs for materials and assembly time compared to conventional adsorption chillers.

None

2010-10-01T23:59:59.000Z

34

High-Efficiency, Self-Concentrating Nanoscale Solar Cell  

While solar cells have the potential to provide clean energy for a large portion of the earth's population, no one technology has provided the right ...

35

High Efficiency Multiple-Junction Solar Cells - Energy ...  

Technology Marketing Summary Single junction solar cells have limited efficiency and fail to extract maximum energy from photons outside of a specific ...

36

Available Technologies: Highly Efficient Multigap Solar Cell Materials  

Scientists at Berkeley Lab have invented multiband gap semiconducting materials for developing solar cells that could achieve power conversion efficiencies of 50 ...

37

High-Efficiency, Self-Concentrating Nanoscale Solar Cell - Energy ...  

While solar cells have the potential to provide clean energy for a large portion of the earth’s population, no one technology has provided the right combination of ...

38

Conversion Tower for Dispatchable Solar Power: High-Efficiency Solar-Electric Conversion Power Tower  

Science Conference Proceedings (OSTI)

HEATS Project: Abengoa Solar is developing a high-efficiency solar-electric conversion tower to enable low-cost, fully dispatchable solar energy generation. Abengoa’s conversion tower utilizes new system architecture and a two-phase thermal energy storage media with an efficient supercritical carbon dioxide (CO2) power cycle. The company is using a high-temperature heat-transfer fluid with a phase change in between its hot and cold operating temperature. The fluid serves as a heat storage material and is cheaper and more efficient than conventional heat-storage materials, like molten salt. It also allows the use of a high heat flux solar receiver, advanced high thermal energy density storage, and more efficient power cycles.

None

2012-01-11T23:59:59.000Z

39

Full-Spectrum Semiconducting Material for Affordable, Highly Efficient Solar Cells  

Wladyslaw Walukiewicz and Kin Man Yu of Berkeley Lab have designed a new semiconducting material that will enable the fabrication of high efficiency solar cells at a fraction of the price of other technologies. 

40

New approaches for high-efficiency solar cells. Final report  

DOE Green Energy (OSTI)

This report summarizes the activities carried out in this subcontract. These activities cover, first the atomic layer epitaxy (ALE) growth of GaAs, AlGaAs and InGaP at fairly low growth temperatures. This was followed by using ALE to achieve high levels of doping both n-type and p-type required for tunnel junctions (Tj) in the cascade solar cell structures. Then the authors studied the properties of AlGaAs/InGaP and AlGaAs/GaAs tunnel junctions and their performances at different growth conditions. This is followed by the use of these tunnel junctions in stacked solar cell structures. The effect of these tunnel junctions on the performance of stacked solar cells was studied at different temperatures and different solar fluences. Finally, the authors studied the effect of different types of black surface fields (BSF), both p/n and n/p GaInP solar cell structures, and their potential for window layer applications. Parts of these activities were carried in close cooperation with Dr. Mike Timmons of the Research Triangle Institute.

Bedair, S.M.; El-Masry, N.A. [North Carolina State Univ., Raleigh, NC (United States)

1997-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "high-efficiency organic solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

High-efficiency solar cells using HEM silicon  

DOE Green Energy (OSTI)

Developments in Heat Exchanger Method (HEM) technology for production of multicrystalline silicon ingot production have led to growth of larger ingots (55 cm square cross section) with lower costs and reliability in production. A single reusable crucible has been used to produce 18 multicrystalline 33 cm square cross section 40 kg ingots, and capability to produce 44 cm ingots has been demonstrated. Large area solar cells of 16.3% (42 cm{sup 2}) and 15.3% (100 cm{sup 2}) efficiency have been produced without optimization of the material production and the solar cell processing.

Khattak, C.P.; Schmid, F. [Crystal Systems, Inc., Salem, MA (United States); Schubert, W.K. [Sandia National Labs., Albuquerque, NM (United States)

1994-12-31T23:59:59.000Z

42

Design for the fabrication of high efficiency solar cells  

DOE Patents (OSTI)

A method and apparatus for a photo-active region for generation of free carriers when a first surface is exposed to optical radiation. The photo-active region includes a conducting transparent matrix and clusters of semiconductor materials embedded within the conducting transparent matrix. The clusters are arranged in the matrix material so as to define at least a first distribution of cluster sizes ranging from those with the highest bandgap energy near a light incident surface of the photo-active region to those with the smallest bandgap energy near an opposite second surface of the photo-active region. Also disclosed is a method and apparatus for a solar cell. The solar cell includes a photo-active region containing a plurality of semiconductor clusters of varying sizes as described.

Simmons, Joseph H. (Gainesville, FL)

1998-01-01T23:59:59.000Z

43

High Efficiency and High Rate Deposited Amorphous Silicon-Based Solar Cells  

E-Print Network (OSTI)

of a triple cell showing 10.7% stable efficiency. Figure 4-1 Schematic diagram of the Hot Wire CVD deposition. Task 7: High-rate deposition of a-Si based solar cells We have conducted extensive research using a hot1 High Efficiency and High Rate Deposited Amorphous Silicon-Based Solar Cells PHASE I Annual

Deng, Xunming

44

High-Efficiency Solar Cells for Large-Scale Electricity Generation  

DOE Green Energy (OSTI)

One strategy for helping the solar industry to grow faster is to use very high efficiency cells under concentrating optics. By using lenses or mirrors to concentrate the light, very small solar cells can be used, reducing the amount of semiconductor material and allowing use of higher efficiency cells, which are now >40% efficient.

Kurtz, S.; Olson, J.; Geisz, J.; Friedman, D.; McMahon, W.; Ptak, A.; Wanlass, M.; Kibbler, A.; Kramer, C.; Bertness, K.; Ward, S.; Duda, A.; Young, M.; Carapella, J.; Steiner, M.

2008-09-26T23:59:59.000Z

45

Quantum Dot Solar Cells: High Efficiency through Multiple Exciton Generation  

DOE Green Energy (OSTI)

Impact ionization is a process in which absorbed photons in semiconductors that are at least twice the bandgap can produce multiple electron-hole pairs. For single-bandgap photovoltaic devices, this effect produces greatly enhanced theoretical thermodynamic conversion efficiencies that range from 45-85%, depending upon solar concentration, the cell temperature, and the number of electron-hole pairs produced per photon. For quantum dots (QDs), electron-hole pairs exist as excitons. We have observed astoundingly efficient multiple exciton generation (MEG) in QDs of PbSe (bulk Eg = 0.28 eV), ranging in diameter from 3.9 to 5.7nm (Eg = 0.73, 0.82, and 0.91 eV, respectively). The effective masses of electron and holes are about equal in PbSe, and the onset for efficient MEG occurs at about three times the QD HOMO-LUMO transition (its ''bandgap''). The quantum yield rises quickly after the onset and reaches 300% at 4 x Eg (3.64 eV) for the smallest QD; this means that every QD in the sample produces three electron-hole pairs/photon.

Hanna, M. C.; Ellingson, R. J.; Beard, M.; Yu, P.; Micic, O. I.; Nozik, A. J.; c.

2005-01-01T23:59:59.000Z

46

Light Trapping for High Efficiency Heterojunction Crystalline Si Solar Cells: Preprint  

DOE Green Energy (OSTI)

Light trapping plays an important role to achieve high short circuit current density (Jsc) and high efficiency for amorphous/crystalline Si heterojunction solar cells. Si heterojunction uses hydrogenated amorphous Si for emitter and back contact. This structure of solar cell posses highest open circuit voltage of 0.747 V at one sun for c-Si based solar cells. It also suggests that over 25% record-high efficiency is possible with further improvement of Jsc. Light trapping has two important tasks. The first one is to reduce the surface reflectance of light to zero for the solar spectrum that Si has a response. The second one is to increase the effective absorption length to capture all the photon. For Si heterojunction solar cell, surface texturing, anti-reflectance indium tin oxides (ITO) layer at the front and back are the key area to improve the light trapping.

Wang, Q.; Xu, Y.; Iwaniczko, E.; Page, M.

2011-04-01T23:59:59.000Z

47

Fundamental understanding and development of low-cost, high-efficiency silicon solar cells  

DOE Green Energy (OSTI)

The overall objectives of this program are (1) to develop rapid and low-cost processes for manufacturing that can improve yield, throughput, and performance of silicon photovoltaic devices, (2) to design and fabricate high-efficiency solar cells on promising low-cost materials, and (3) to improve the fundamental understanding of advanced photovoltaic devices. Several rapid and potentially low-cost technologies are described in this report that were developed and applied toward the fabrication of high-efficiency silicon solar cells.

ROHATGI,A.; NARASIMHA,S.; MOSCHER,J.; EBONG,A.; KAMRA,S.; KRYGOWSKI,T.; DOSHI,P.; RISTOW,A.; YELUNDUR,V.; RUBY,DOUGLAS S.

2000-05-01T23:59:59.000Z

48

High Efficiency, Low Cost Solar Cells Manufactured Using 'Silicon Ink' on Thin Crystalline Silicon Wafers  

DOE Green Energy (OSTI)

Reported are the development and demonstration of a 17% efficient 25mm x 25mm crystalline Silicon solar cell and a 16% efficient 125mm x 125mm crystalline Silicon solar cell, both produced by Ink-jet printing Silicon Ink on a thin crystalline Silicon wafer. To achieve these objectives, processing approaches were developed to print the Silicon Ink in a predetermined pattern to form a high efficiency selective emitter, remove the solvents in the Silicon Ink and fuse the deposited particle Silicon films. Additionally, standard solar cell manufacturing equipment with slightly modified processes were used to complete the fabrication of the Silicon Ink high efficiency solar cells. Also reported are the development and demonstration of a 18.5% efficient 125mm x 125mm monocrystalline Silicon cell, and a 17% efficient 125mm x 125mm multicrystalline Silicon cell, by utilizing high throughput Ink-jet and screen printing technologies. To achieve these objectives, Innovalight developed new high throughput processing tools to print and fuse both p and n type particle Silicon Inks in a predetermined pat-tern applied either on the front or the back of the cell. Additionally, a customized Ink-jet and screen printing systems, coupled with customized substrate handling solution, customized printing algorithms, and a customized ink drying process, in combination with a purchased turn-key line, were used to complete the high efficiency solar cells. This development work delivered a process capable of high volume producing 18.5% efficient crystalline Silicon solar cells and enabled the Innovalight to commercialize its technology by the summer of 2010.

Antoniadis, H.

2011-03-01T23:59:59.000Z

49

Highly-Efficient Thermoelectronic Conversion of Solar Energy and Heat into Electric Power  

E-Print Network (OSTI)

Electric power may, in principle, be generated in a highly efficient manner from heat created by focused solar irradiation, chemical combustion, or nuclear decay by means of thermionic energy conversion. As the conversion efficiency of the thermionic process tends to be degraded by electron space charges, the efficiencies of thermionic generators have amounted to only a fraction of those fundamentally possible. We show that this space-charge problem can be resolved by shaping the electric potential distribution of the converter such that the static electron space-charge clouds are transformed into an output current. Although the technical development of practical generators will require further substantial efforts, we conclude that a highly efficient transformation of heat to electric power may well be achieved.

Meir, S; Geballe, T H; Mannhart, J

2013-01-01T23:59:59.000Z

50

New concepts for high efficiency energy conversion: The avalanche heterostructure and superlattice solar cells  

DOE Green Energy (OSTI)

This report describes investigation into the theory and technology of a novel heterojunction or superlattice, single-junction solar cell, which injects electrons across the heterointerface to produce highly efficient impact ionization of carriers in the lowband-gap side of the junction, thereby conserving their total energy. Also, the superlattice structure has the advantage of relaxing the need for perfect lattice matching at the p-n interface and will inhibit the cross diffusion of dopant atoms that typically occurs in heavy doping. This structure avoids the use of tunnel junctions that make it very difficult to achieve the predicted efficiencies in cascade cells, thus making it possible to obtain energy efficiencies that are competitive with those predicted for cascade solar cells with reduced complexity and cost. This cell structure could also be incorporated into other solar cell structures designed for wider spectral coverage.

Summers, C.J.; Rohatgi, A.; Torabi, A.; Harris, H.M. (Georgia Tech Research Inst., Atlanta, GA (United States))

1993-01-01T23:59:59.000Z

51

Low cost, single crystal-like substrates for practical, high efficiency solar cells  

Science Conference Proceedings (OSTI)

It is well established that high efficiency (20%) solar cells can be routinely fabricated using single crystal photovoltaic (PV) materials with low defect densities. Polycrystalline materials with small grain sizes and no crystallographic texture typically result in reduced efficiences. This has been ascribed primarily to the presence of grain boundaries and their effect on recombination processes. Furthermore, lack of crystallographic texture can result in a large variation in dopant concentrations which critically control the electronic properties of the material. Hence in order to reproducibly fabricate high efficiency solar cells a method which results in near single crystal material is desirable. Bulk single crystal growth of PV materials is cumbersome, expensive and difficult to scale up. We present here a possible route to achieve this if epitaxial growth of photovoltaic materials on rolling-assisted-biaxially textured-substrates (RABiTS) can be achieved. The RABiTS process uses well-established, industrially scaleable, thermomechanical processing to produce a biaxially textured or single-crystal-like metal substrate with large grains (50-100 {mu}m). This is followed by epitaxial growth of suitable buffer layers to yield chemically and structurally compatible surfaces for epitaxial growth of device materials. Using the RABiTS process it should be possible to economically fabricate single-crystal-like substrates of desired sizes. Epitaxial growth of photovoltaic devices on such substrates presents a possible route to obtaining low-cost, high performance solar cells.

Goyal, A.; Specht, E.D.; List, F.A. [and others

1997-09-01T23:59:59.000Z

52

High Efficiency Nanostructured III-V Photovoltaics for Solar Concentrator Application  

DOE Green Energy (OSTI)

The High Efficiency Nanostructured III-V Photovoltaics for Solar Concentrators project seeks to provide new photovoltaic cells for Concentrator Photovoltaics (CPV) Systems with higher cell efficiency, more favorable temperature coefficients and less sensitivity to changes in spectral distribution. The main objective of this project is to provide high efficiency III-V solar cells that will reduce the overall cost per Watt for power generation using CPV systems.This work is focused both on a potential near term application, namely the use of indium arsenide (InAs) QDs to spectrally "tune" the middle (GaAs) cell of a SOA triple junction device to a more favorable effective bandgap, as well as the long term goal of demonstrating intermediate band solar cell effects. The QDs are confined within a high electric field i-region of a standard GaAs solar cell. The extended absorption spectrum (and thus enhanced short circuit current) of the QD solar cell results from the increase in the sub GaAs bandgap spectral response that is achievable as quantum dot layers are introduced into the i-region. We have grown InAs quantum dots by OMVPE technique and optimized the QD growth conditions. Arrays of up to 40 layers of strain balanced quantum dots have been experimentally demonstrated with good material quality, low residual stain and high PL intensity. Quantum dot enhanced solar cells were grown and tested under simulated one sun AM1.5 conditions. Concentrator solar cells have been grown and fabricated with 5-40 layers of QDs. Testing of these devices show the QD cells have improved efficiency compared to baseline devices without QDs. Device modeling and measurement of thermal properties were performed using Crosslight APSYS. Improvements in a triple junction solar cell with the insertion of QDs into the middle current limiting junction was shown to be as high as 29% under one sun illumination for a 10 layer stack QD enhanced triple junction solar cell. QD devices have strong potential for net gains in efficiency at high concentration.

Hubbard, Seth

2012-09-12T23:59:59.000Z

53

Development of high-efficiency silicon solar cells and modeling the impact of system parameters on levelized cost of electricity .  

E-Print Network (OSTI)

??The objective of this thesis is to develop low-cost high-efficiency crystalline silicon solar cells which are at the right intersection of cost and performance to… (more)

Kang, Moon Hee

2013-01-01T23:59:59.000Z

54

Simulation of Device Parameters of High Efficiency Multicrystalline Silicon Solar Cells  

Science Conference Proceedings (OSTI)

The results of the simulation of the reported experimental results of high efficiency multicrystalline silicon (mc-Si) solar cells, using PC1D software, are reported in this study. Results obtained by various groups have been incorporated and compared in this study. The highest efficiency reported so far for mc-Si solar cells is 20{center_dot}4% and 17-18% by research laboratories and commercial houses, respectively. The efficiency can be further enhanced if passivation characteristics on both the front and back surface are improved. The role of back surface recombination has become more significant in light of the use of thin mc-Si wafers by the solar cell industry. Based on the passivation characteristics and considering the understanding of the past three decades of studies, the authors have proposed and simulated a structure for mc-Si solar cells to improve the performance of the same. The results of our modeled structure of mc-Si solar cell show an efficiency of 21{center_dot}88% with short-circuit current density, J{sub sc} = 39{center_dot}39 mA/cm2, and open circuit voltage, V{sub oc} = 0{center_dot}666 V.

Budhraja, V.; Misra, D.; Ravindra, N. M.

2011-11-01T23:59:59.000Z

55

Development of manufacturing capability for high-concentration, high-efficiency silicon solar cells  

DOE Green Energy (OSTI)

This report presents a summary of the major results from a program to develop a manufacturable, high-efficiency silicon concentrator solar cell and a cost-effective manufacturing facility. The program was jointly funded by the Electric Power Research Institute, Sandia National Laboratories through the Concentrator Initiative, and SunPower Corporation. The key achievements of the program include the demonstration of 26%-efficient silicon concentrator solar cells with design-point (20 W/cm{sup 2}) efficiencies over 25%. High-performance front-surface passivations; that were developed to achieve this result were verified to be absolutely stable against degradation by 475 days of field exposure at twice the design concentration. SunPower demonstrated pilot production of more than 1500 of these cells. This cell technology was also applied to pilot production to supply 7000 17.7-cm{sup 2} one-sun cells (3500 yielded wafers) that demonstrated exceptional quality control. The average efficiency of 21.3% for these cells approaches the peak efficiency ever demonstrated for a single small laboratory cell within 2% (absolute). Extensive cost models were developed through this program and calibrated by the pilot-production project. The production levels achieved indicate that SunPower could produce 7-10 MW of concentrator cells per year in the current facility based upon the cell performance demonstrated during the program.

Sinton, R.A.; Verlinden, P.J.; Crane, R.A.; Swanson, R.N. [SunPower Corp., Sunnyvale, CA (United States)

1996-10-01T23:59:59.000Z

56

Rapid thermal processing of high-efficiency silicon solar cells with controlled in-situ annealing  

DOE Green Energy (OSTI)

Silicon solar cell efficiencies of 17.1%, 16.4%, 14.8%, and 14.9% have been achieved on FZ, Cz, multicrystalline (mc-Si), and dendritic web (DW) silicon, respectively, using simplified, cost-effective rapid thermal processing (RTP). These represent the highest reported efficiencies for solar cells processed with simultaneous front and back diffusion with no conventional high-temperature furnace steps. Appropriate diffusion temperature coupled with the added in-situ anneal resulted in suitable minority-carrier lifetime and diffusion profiles for high-efficiency cells. The cooling rate associated with the in-situ anneal can improve the lifetime and lower the reverse saturation current density (J{sub 0}), however, this effect is material and base resistivity specific. PECVD antireflection (AR) coatings provided low reflectance and efficient front surface and bulk defect passivation. Conventional cells fabricated on FZ silicon by furnace diffusions and oxidations gave an efficiency of 18.8% due to greater short wavelength response and lower J{sub 0}.

Doshi, P.; Rohatgi, A.; Ropp, M.; Chen, Z. [Georgia Institute of Technology, Atlanta, GA (United States). Univ. Center of Excellence for Photovoltaics Research and Education; Ruby, D. [Sandia National Labs., Albuquerque, NM (United States); Meier, D.L. [EBARA Solar, Inc., Large, PA (United States)

1995-01-01T23:59:59.000Z

57

High Efficiency Single Crystal CdTe Solar Cells: November 19, 2009 - January 31, 2011  

DOE Green Energy (OSTI)

The goal of the program was to develop single crystal CdTe-based top cells grown on Si solar cells as a platform for the subsequent manufacture of high efficiency tandem cells for CPV applications. The keys to both the single junction and the tandem junction cell architectures are the ability to grow high quality single-crystal CdTe and CdZnTe layers on p-type Si substrates, to dope the CdTe and CdZnTe controllably, both n and p-type, and to make low resistance ohmic front and back contacts. EPIR demonstrated the consistent MBE growth of CdTe/Si and CdZnTe/Si having high crystalline quality despite very large lattice mismatches; epitaxial CdTe/Si and CdZnTe/Si consistently showed state-of-the-art electron mobilities and good hole mobilities; bulk minority carrier recombination lifetimes of unintentionally p-doped CdTe and CdZnTe grown by MBE on Si were demonstrated to be consistently of order 100 ns or longer; desired n- and p-doping levels were achieved; solar cell series specific resistances <10 ?-cm2 were achieved; A single-junction solar cell having a state-of-the-art value of Voc and a unverified 16.4% efficiency was fabricated from CdZnTe having a 1.80 eV bandgap, ideal for the top junction in a tandem cell with a Si bottom junction.

Carmody, M.; Gilmore, A.

2011-05-01T23:59:59.000Z

58

Turning Bacteria into Fuel: Cyanobacteria Designed for Solar-Powered Highly Efficient Production of Biofuels  

SciTech Connect

Broad Funding Opportunity Announcement Project: ASU is engineering a type of photosynthetic bacteria that efficiently produce fatty acids—a fuel precursor for biofuels. This type of bacteria, called Synechocystis, is already good at converting solar energy and carbon dioxide (CO2) into a type of fatty acid called lauric acid. ASU has modified the organism so it continuously converts sunlight and CO2 into fatty acids—overriding its natural tendency to use solar energy solely for cell growth and maximizing the solar-to-fuel conversion process. ASU’s approach is different because most biofuels research focuses on increasing cellular biomass and not on excreting fatty acids. The project has also identified a unique way to convert the harvested lauric acid into a fuel that can be easily blended with existing transportation fuels.

2010-01-01T23:59:59.000Z

59

Development of high efficiency (14%) solar cell array module. Final report, November 1979-June 1980  

DOE Green Energy (OSTI)

More effort was concentrated on development of procedures to provide large area (3 in. dia) high efficiency (16.5% AM1, 28/sup 0/C) P+NN+ solar cells. Intensive tests with 3 in. slices gave consistently lower efficiency (13.5%). The problems were identified as incomplete formation of an optimum back surface field (BSF), and interaction of the BSF process and the shallow P+ junction. The problem was shown not to be caused by reduced quality of silicon near the edges of the larger slices. A promising process sequence was identified. A reasonably large number of fairly efficient (13.5% average) 3 in. P+NN+ cells were made and combined with no problems with the module design developed for this project. In the module, one hundred and twenty (120) cells were connected, eight (8) in parallel and fifteen (15) in series. Six (6) modules were delivered with an average power output (per total module area of 6890 cm/sup 2/) of 75.3 watts and a module overall average efficiency of 10.9%.

Iles, P.A.; Khemthong, S.; Olah, S.; Sampson, W.J.; Ling, K.S.

1980-01-01T23:59:59.000Z

60

Research on high-efficiency, single-junction, monolithic, thin-film amorphous silicon solar cells  

DOE Green Energy (OSTI)

This document describes the progress made in obtaining stable, a-Si-based submodules that have a large area and high efficiency. Conversion efficiencies of up to 11.95% were obtained in small-area, single-junction a-Si solar cells using textured TiO{sub 2}, superlattice p-layers, graded carbon concentrations near the p/i interface, and highly reflective ITO/silver back contacts. Single- junction a-SiC and a-SiGe p-i-n cells were also fabricated that had conversion efficiencies of 9%--11%, and some recently fabricated stacked-junction cells had conversion efficiencies of about 10%. In materials research boron-doped microcrystalline SiC films were recently developed containing up to 6 at. % carbon with conductivities of 3 {times} 10{sup {minus}3}/{Omega}-cm at room temperature and activation energies of 0.11 eV. Microcrystalline film growth was shown to be strongly influenced by the nature of the substrate, with nucleation occurring more readily on a-Si substrates than on TiO{sub 2}. Stability studies show that light-induced degradation is usually enhanced by the presence of carbon grading near the p/i interface. In general, adding either germanium (from GeH{sub 4}) or carbon (from CH{sub 4}) to the i-layer of a p-i-n cell leads to enhanced light-induced degradation. 13 refs., 80 figs., 17 tabs.

Catalano, A.W.; Carlson, D.E.; Ayra, R.R.; Bennett, M.S.; D'Aiello, R.V.; Dickson, C.R.; Fortmann, C.M.; Goldstein, B.; McVeigh, J.; Morris, J.; Newton, J.L.; Wiedeman, S. (Solarex Corp., Newtown, PA (USA). Thin Film Div.)

1989-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "high-efficiency organic solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

High mobility high efficiency organic films based on pure organic materials  

SciTech Connect

A method of purifying small molecule organic material, performed as a series of operations beginning with a first sample of the organic small molecule material. The first step is to purify the organic small molecule material by thermal gradient sublimation. The second step is to test the purity of at least one sample from the purified organic small molecule material by spectroscopy. The third step is to repeat the first through third steps on the purified small molecule material if the spectroscopic testing reveals any peaks exceeding a threshold percentage of a magnitude of a characteristic peak of a target organic small molecule. The steps are performed at least twice. The threshold percentage is at most 10%. Preferably the threshold percentage is 5% and more preferably 2%. The threshold percentage may be selected based on the spectra of past samples that achieved target performance characteristics in finished devices.

Salzman, Rhonda F. (Ann Arbor, MI); Forrest, Stephen R. (Ann Arbor, MI)

2009-01-27T23:59:59.000Z

62

High efficiency resonant dc/dc converter for solar power applications  

E-Print Network (OSTI)

This thesis presents a new topology for a high efficiency dc/dc resonant power converter that utilizes a resistance compression network to provide simultaneous zero voltage switching and near zero current switching across ...

Inam, Wardah

2013-01-01T23:59:59.000Z

63

Design and global optimization of high-efficiency solar thermal systems with tungsten cermets  

E-Print Network (OSTI)

Solar thermal, thermoelectric, and thermophotovoltaic (TPV) systems have high maximum theoretical efficiencies; experimental systems fall short because of losses by selective solar absorbers and TPV selective emitters. To ...

Chester, David A.

64

The effects of concentrated ultraviolet light on high-efficiency silicon solar cells  

DOE Green Energy (OSTI)

The importance of stability in the performance of solar cells is clearly recognized as fundamental. Some of the highest efficiency silicon solar cells demonstrated to date, such as the Point Contact solar cell and the Passivated Emitter solar cell, rely upon the passivation of cell surfaces in order to minimize recombination, which reduces cell power output. Recently, it has been shown that exposure to ultraviolet (UV) light of wavelengths present in the terrestrial solar spectrum can damage a passivating silicon-oxide interface and increase recombination. In this study, we compared the performance of Point Contact and Passivated Emitter solar cells after exposure to UV light. We also examined the effect of UV exposure on oxide-passivated silicon wafers. We found that current Passivated Emitter designs are stable at both one-sun and under concentrated sunlight. The evolution of Point Contact concentrator cell performance shows a clear trend towards more stable cells. 15 refs., 18 figs.

Ruby, D.S.; Schubert, W.K.

1991-01-01T23:59:59.000Z

65

NREL Produces Highly Efficient, Wide-Bandgap, Thin-Film Solar Cells (Fact Sheet)  

Science Conference Proceedings (OSTI)

Researchers at the National Renewable Energy Laboratory (NREL) are finding new ways to manufacture thin-film solar cells made from copper, indium, gallium, and selenium - called CIGS cells - that are different than conventional CIGS solar cells. Their use of high-temperature glass, designed by SCHOTT AG, allows higher fabrication temperatures, opening the door to new CIGS solar cells employing light-absorbing materials with wide 'bandgaps.'

Not Available

2012-09-01T23:59:59.000Z

66

Advanced laser processing and photoluminescence characterisation of high efficiency silicon solar cells.  

E-Print Network (OSTI)

??Many current technologies used in solar cell fabrication have been successfully adapted from the integrated circuits industry. The success of laser processing applications in this… (more)

Abbott, Malcolm David

2006-01-01T23:59:59.000Z

67

High-efficiency cadmium and zinc-telluride-based thin-film solar cells  

DOE Green Energy (OSTI)

This report describes research into polycrystalline CdTe solar cells grown by metal-organic chemical vapor deposition. Efficiencies of {approximately}10% were achieved using both p-i-n and p-n structures. A pre-heat treatment of CdS/SnO{sub 2}/glass substrates at 450{degrees}C in hydrogen atmosphere prior to the CdTe growth was found to be essential for high performance because this heat treatment reduces oxygen-related defects from the CdS surface. However, this treatment also resulted in a Cd-deficient CdS surface, which may in part limit the CdTe cell efficiency to 10% due to Cd vacancy-related interface defects. Preliminary model calculations suggest that removing these states can increase the cell efficiency from 10% to 13.5%. Photon absorption in the CdS film also limits the cell performance, and eliminating this loss mechanism can result in CdTe efficiencies in excess of 18%. Polycrystalline, 1.7-e, CdZnTe films were also grown for tandem-cell applications. CdZnTe/CdS cells processed using the standard CdTe cell fabrication procedure resulted in 4.4% efficiency, high series resistance, and a band-gap shift to 1.55 eV. The formation of Zn-O at and near the CdZnTe surface is the source of high contact resistance. A saturated dichromate each prior to contact deposition was found to solve the contact resistance problem. The CdCl{sub 2} treatment was identified as the cause of the observed band-gap shift due to the preferred formation of ZnCl{sub 2}. 59 refs.

Rohatgi, A.; Sudharsanan, R.; Ringel, S. (Georgia Inst. of Tech., Atlanta, GA (United States))

1992-02-01T23:59:59.000Z

68

InGaAsN: A Novel Material for High-Efficiency Solar Cells and Advanced Photonic Devices  

DOE Green Energy (OSTI)

This report represents the completion of a 6 month Laboratory-Directed Research and Development (LDRD) program that focused on research and development of novel compound semiconductor, InGaAsN. This project seeks to rapidly assess the potential of InGaAsN for improved high-efficiency photovoltaic. Due to the short time scale, the project focused on quickly investigating the range of attainable compositions and bandgaps while identifying possible material limitations for photovoltaic devices. InGaAsN is a new semiconductor alloy system with the remarkable property that the inclusion of only 2% nitrogen reduces the bandgap by more than 30%. In order to help understand the physical origin of this extreme deviation from the typically observed nearly linear dependence of alloy properties on concentration, we have investigated the pressure dependence of the excited state energies using both experimental and theoretical methods. We report measurements of the low temperature photoluminescence energy of the material for pressures between ambient and 110 kbar. We describe a simple, density-functional-theory-based approach to calculating the pressure dependence of low lying excitation energies for low concentration alloys. The theoretically predicted pressure dependence of the bandgap is in excellent agreement with the experimental data. Based on the results of our calculations, we suggest an explanation for the strongly non-linear pressure dependence of the bandgap that, surprisingly, does not involve a nitrogen impurity band. Additionally, conduction-band mass measurements, measured by three different techniques, will be described and finally, the magnetoluminescence determined pressure coefficient for the conduction-band mass is measured. The design, growth by metal-organic chemical vapor deposition, and processing of an In{sub 0.07}Ga{sub 0.93}As{sub 0.98}N{sub 0.02} solar cell, with 1.0 eV bandgap, lattice matched to GaAs is described. The hole diffusion length in annealed, n-type InGaAsN is 0.6-0.8 pm, and solar cell internal quantum efficiencies >70% are obtained. Optical studies indicate that defects or impurities, from doping and nitrogen incorporation, limit cell performance.

Allerman, Andrew A.; Follstaedt, David M.; Gee, James M.; Jones, Eric D.; Kurtz, Steven R.; Modine, Norman A.

1999-07-01T23:59:59.000Z

69

Development of high efficiency cascade solar cells. Quarterly technical progress report No. 2  

DOE Green Energy (OSTI)

Research has continued in the development of selected ternary and quaternary III-V materials that are potential candidates for cascade solar cell applications. In addition, various simple and multi-junction cascade solar cell components have been fabricated and evaluated in a continuing study of several different solar cell designs (materials combinations). During the present reporting period, work has concentrated on the following major areas: GaAlAs/GaAs cell development; AlGaAsSb/GaAsSb materials development; GaInP materials development via VPE; inverted structure development; and MO/CVD growth system work at NCSU. Progress in each of these areas is summarized.

Not Available

1979-12-31T23:59:59.000Z

70

Novel InGaAsN pn Junction for High-Efficiency Multiple-Junction Solar Cells  

DOE Green Energy (OSTI)

We report the application of a novel material, InGaAsN, with bandgap energy of 1.05 eV as a junction in an InGaP/GaAs/InGaAsN/Ge 4-junction design. Results of the growth and structural, optical, and electrical properties were demonstrated, showing the promising perspective of this material for ultra high efficiency solar cells. Photovoltaic properties of an as-grown pn diode structure and improvement through post growth annealing were also discussed.

Allerman, A.A.; Chang, P.C.; Gee, J.M.; Hammons, B.E.; Hou, H.Q.; Jones, E.D.; Kurtz, S.R.; Reinhardt, K.C.

1999-03-26T23:59:59.000Z

71

Earth abundant materials for high efficiency heterojunction thin film solar cells  

E-Print Network (OSTI)

We investigate earth abundant materials for thin-film solar cells that can meet tens of terawatts level deployment potential. Candidate materials are identified by combinatorial search, large-scale electronic structure ...

Buonassisi, Tonio

72

High-Efficiency 6?? Multicrystalline Black Solar Cells Based on Metal-Nanoparticle-Assisted Chemical Etching  

E-Print Network (OSTI)

Multicrystalline silicon (mc-Si) photovoltaic (PV) solar cells with nanoscale surface texturing by metal-nanoparticle-assisted etching are proposed to achieve high power efficiency. The investigation of average nanorod ...

Hsu, W. Chuck

2012-01-01T23:59:59.000Z

73

MOVPE Growth of High Efficiency Inverted Metamorphic 1.1eV Solar ...  

Science Conference Proceedings (OSTI)

This paper focuses on the 1.1ev Ga0.77In0.23As inverted metamorphic solar cell grown with AlGaInAs quarternary step graded buffer on 6o miscut (001) thin Ge ...

74

A market analysis for high efficiency multi-junction solar cells grown on SiGe  

E-Print Network (OSTI)

Applications, markets and a cost model are presented for III-V multi-junction solar cells built on compositionally graded SiGe buffer layers currently being developed by professors Steven Ringell of Ohio State University ...

Judkins, Zachara Steele

2007-01-01T23:59:59.000Z

75

Silicon Ink for High-Efficiency Solar Cells Captures a Share of the Market (Fact Sheet)  

DOE Green Energy (OSTI)

Fact sheet on 2011 R&D 100 Award winner Silicon Ink. Liquid silicon has arrived, and with it comes a power boost for solar cells and dramatic cost savings for cell manufacturers.

Not Available

2011-08-01T23:59:59.000Z

76

NREL Produces Highly Efficient, Wide-Bandgap, Thin-Film Solar...  

NLE Websites -- All DOE Office Websites (Extended Search)

Low-bandgap cells can lose 25% of their power output and efficiency ratings as solar cell operating temperatures climb to 75C or more, a common occurrence in hot and arid...

77

High efficiency thin film silicon solar cells with novel light trapping : principle, design and processing  

E-Print Network (OSTI)

One major efficiency limiting factor in thin film solar cells is weak absorption of long wavelength photons due to the limited optical path length imposed by the thin film thickness. This is especially severe in Si because ...

Zeng, Lirong, Ph. D. Massachusetts Institute of Technology

2008-01-01T23:59:59.000Z

78

Novel wide band gap materials for highly efficient thin film tandem solar cells  

SciTech Connect

Tandem solar cells (TSCs), which use two or more materials to absorb sunlight, have achieved power conversion efficiencies of >25% versus 11-20% for commercialized single junction solar cell modules. The key to widespread commercialization of TSCs is to develop the wide-band, top solar cell that is both cheap to fabricate and has a high open-circuit voltage (i.e. >1V). Previous work in TSCs has generally focused on using expensive processing techniques with slow growth rates resulting in costs that are two orders of magnitude too expensive to be used in conventional solar cell modules. The objective of the PLANT PV proposal was to investigate the feasibility of using Ag(In,Ga)Se2 (AIGS) as the wide-bandgap absorber in the top cell of a thin film tandem solar cell (TSC). Despite being studied by very few in the solar community, AIGS solar cells have achieved one of the highest open-circuit voltages within the chalcogenide material family with a Voc of 949mV when grown with an expensive processing technique (i.e. Molecular Beam Epitaxy). PLANT PV�s goal in Phase I of the DOE SBIR was to 1) develop the chemistry to grow AIGS thin films via solution processing techniques to reduce costs and 2) fabricate new device architectures with high open-circuit voltage to produce full tandem solar cells in Phase II. PLANT PV attempted to translate solution processing chemistries that were successful in producing >12% efficient Cu(In,Ga)Se2 solar cells by replacing copper compounds with silver. The main thrust of the research was to determine if it was possible to make high quality AIGS thin films using solution processing and to fully characterize the materials properties. PLANT PV developed several different types of silver compounds in an attempt to fabricate high quality thin films from solution. We found that silver compounds that were similar to the copper based system did not result in high quality thin films. PLANT PV was able to deposit AIGS thin films using a mixture of solution and physical vapor deposition processing, but these films lacked the p-type doping levels that are required to make decent solar cells. Over the course of the project PLANT PV was able to fabricate efficient CIGS solar cells (8.7%) but could not achieve equivalent performance using AIGS. During the nine-month grant PLANT PV set up a variety of thin film characterization tools (e.g. drive-level capacitance profiling) at the Molecular Foundry, a Department of Energy User Facility, that are now available to both industrial and academic researchers via the grant process. PLANT PV was also able to develop the back end processing of thin film solar cells at Lawrence Berkeley National Labs to achieve 8.7% efficient CIGS solar cells. This processing development will be applied to other types of thin film PV cells at the Lawrence Berkeley National Labs. While PLANT PV was able to study AIGS film growth and optoelectronic properties we concluded that AIGS produced using these methods would have a limited efficiency and would not be commercially feasible. PLANT PV did not apply for the Phase II of this grant.

Brian E. Hardin, Stephen T. Connor, Craig H. Peters

2012-06-11T23:59:59.000Z

79

High Efficiency Generation of Hydrogen Fuels Using Solar Thermochemical Splitting of Water  

SciTech Connect

The objective of this work is to identify economically feasible concepts for the production of hydrogen from water using solar energy. The ultimate project objective was to select one or more competitive concepts for pilot-scale demonstration using concentrated solar energy. Results of pilot scale plant performance would be used as foundation for seeking public and private resources for full-scale plant development and testing. Economical success in this venture would afford the public with a renewable and limitless source of energy carrier for use in electric power load-leveling and as a carbon-free transportation fuel. The Solar Hydrogen Generation Research (SHGR) project embraces technologies relevant to hydrogen research under the Office of Hydrogen Fuel Cells and Infrastructure Technology (HFCIT) as well as concentrated solar power under the Office of Solar Energy Technologies (SET). Although the photoelectrochemical work is aligned with HFCIT, some of the technologies in this effort are also consistent with the skills and technologies found in concentrated solar power and photovoltaic technology under the Office of Solar Energy Technologies (SET). Hydrogen production by thermo-chemical water-splitting is a chemical process that accomplishes the decomposition of water into hydrogen and oxygen using only heat or a combination of heat and electrolysis instead of pure electrolysis and meets the goals for hydrogen production using only water and renewable solar energy as feed-stocks. Photoelectrochemical hydrogen production also meets these goals by implementing photo-electrolysis at the surface of a semiconductor in contact with an electrolyte with bias provided by a photovoltaic source. Here, water splitting is a photo-electrolytic process in which hydrogen is produced using only solar photons and water as feed-stocks. The thermochemical hydrogen task engendered formal collaborations among two universities, three national laboratories and two private sector entities. The photoelectrochemical hydrogen task included formal collaborations with three universities and one national laboratory. The formal participants in these two tasks are listed above. Informal collaborations in both projects included one additional university (the University of Nevada, Reno) and two additional national laboratories (Lawrence Livermore National Laboratory and Lawrence Berkeley National Laboratory).

Heske, Clemens; Moujaes, Samir; Weimer, Alan; Wong, Bunsen; Siegal, Nathan; McFarland, Eric; Miller, Eric; Lewis, Michele; Bingham, Carl; Roth, Kurth; Sabacky, Bruce; Steinfeld, Aldo

2011-09-29T23:59:59.000Z

80

High-efficiency silicon solar cells for use with a prismatic cover at 160 suns  

DOE Green Energy (OSTI)

For this program, Solarex developed a process sequence that could be used in a manufacturing environment to produce high-efficiency silicon concentrator cells. The cells had large gridlines to minimize series resistance losses and a prismatic cover to minimize shadowing. The front surface of the cell was textured to improve absorption of light and passivated to reduce front-surface recombination. Two separate diffusions steps were used: a deep emitter with a light surface concentration and a heavy diffusion to reduce recombination under the front contacts. Cell efficiencies as high as 22.25% were demonstrated at 75 suns and over 21.5% at 150 suns air mass 1.5 illumination. 16 refs., 31 figs., 10 tabs.

Silver, J.R.; Patel, B. (Solarex Corp., Rockville, MD (USA))

1990-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "high-efficiency organic solar" from the National Library of EnergyBeta (NLEBeta).
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81

High efficiency epitaxial optical reflector solar cells. Final subcontract report, 1 January 1990--31 October 1992  

DOE Green Energy (OSTI)

This report describes work to test the feasibility of a new solar cell concept -- the epitaxial optical reflector (EOR) solar cell. This cell concept alters current designs for high efficiency cells by changing the optical absorption efficiency of single cells. The change is introduced by the use an epitaxial multilayer reflector as an integral part of the cell to increase the optical path length of certain wavelengths of light in the cell. These changes are expected to increase the open circuit voltage at which power is extracted from the cell. The program is designed to test the feasibility of the use of a broad band epitaxial multilayer reflector grown as an integral part of the device structure to reflect the near-band-edge light back through the device for a second absorption pass. This second pass allows the design of a solar cell with a thinner base, and the use of the epitaxial reflector as a heterojunction carrier-reflecting barrier at the rear of the device. The thinner cell design and altered carrier profile that results from the light- and carrier-reflecting barrier will decrease the carrier concentration gradient and increase the open circuit voltage. The program is structured to have three tasks: (1) Solar Cell and Reflector Modeling, (2) Materials Growth and Optimization, and (3) Solar Cell Fabrication and Characterization.

Dapkus, P.D.; Hummel, S.G. [University of Southern California, Los Angeles, CA (United States)

1993-08-01T23:59:59.000Z

82

III-V-N materials for super high-efficiency multijunction solar cells  

Science Conference Proceedings (OSTI)

We have been studying concentrator multi-junction solar cells under Japanese Innovative Photovoltaic R and D program since FY2008. InGaAsN is one of appropriate materials for 4-or 5-junction solar cell configuration because this material can be lattice-matched to GaAs and Ge substrates. However, present InGaAsN single-junction solar cells have been inefficient because of low minority-carrier lifetime due to N-related recombination centers and low carrier mobility due to alloy scattering and non-homogeneity of N. This paper presents our major results in the understanding of majority and minority carrier traps in GaAsN grown by chemical beam epitaxy and their relationships with the poor electrical properties of the materials.

Yamaguchi, Masafumi; Bouzazi, Boussairi; Suzuki, Hidetoshi; Ikeda, Kazuma; Kojima, Nobuaki; Ohshita, Yoshio [Toyota Technological Institute, Nagoya 468-8511 (Japan)

2012-10-06T23:59:59.000Z

83

Highly efficient solar collector including means for preventing cover plate fluid condensation  

SciTech Connect

A solar energy collector of low cost and high thermal efficiency is disclosed having a heat trap produced by zigzagging a thin strip of polyethylene terephthalate between opposite sides of the trap while wrapping the strip about rows of dowels positioned at opposite sides of the frame of the solar collector. A window of soda lime glass filters uv radiation to inhibit discoloration of the plastic heat trap walls. An absorber plate having fluid pipes therein is positioned underneath the heat trap and a first layer of fiberglass, and a second layer of polyurethane foam are positioned below the absorber plate. The fiberglass layer prevents overheating of the polyurethane foam layer to in turn inhibit the formation of toxic fluids, which may condense upon the underside of the window to reduce the efficiency of the collector.

Root, E.F.; Kunica, S.; Simmons, H.M.

1977-09-06T23:59:59.000Z

84

Evaluation of Lifetime of High Efficiency Organic Photovoltaic Devices: Cooperative Research and Development Final Report, CRADA Number CRD-10-379  

DOE Green Energy (OSTI)

As a part of this joint work, Solarmer and NREL will investigate the lifetime and stability of Organic Photovoltaic Devices based on Solarmer high efficiency active layer materials.

Olson, D.

2013-04-01T23:59:59.000Z

85

High efficiency thin film CdTe and a-Si based solar cells  

DOE Green Energy (OSTI)

This report describes work done by the University of Toledo during the first year of this subcontract. During this time, the CdTe group constructed a second dual magnetron sputter deposition facility; optimized reactive sputtering for ZnTe:N films to achieve 10 ohm-cm resistivity and {approximately}9% efficiency cells with a copper-free ZnTe:N/Ni contact; identified Cu-related photoluminescence features and studied their correlation with cell performance including their dependence on temperature and E-fields; studied band-tail absorption in CdS{sub x}Te{sub 1{minus}x} films at 10 K and 300 K; collaborated with the National CdTe PV Team on (1) studies of high-resistivity tin oxide (HRT) layers from ITN Energy Systems, (2) fabrication of cells on the HRT layers with 0, 300, and 800-nm CdS, and (3) preparation of ZnTe:N-based contacts on First Solar materials for stress testing; and collaborated with Brooklyn College for ellipsometry studies of CdS{sub x}Te{sub 1{minus}x} alloy films, and with the University of Buffalo/Brookhaven NSLS for synchrotron X-ray fluorescence studies of interdiffusion in CdS/CdTe bilayers. The a-Si group established a baseline for fabricating a-Si-based solar cells with single, tandem, and triple-junction structures; fabricated a-Si/a-SiGe/a-SiGe triple-junction solar cells with an initial efficiency of 9.7% during the second quarter, and 10.6% during the fourth quarter (after 1166 hours of light-soaking under 1-sun light intensity at 50 C, the 10.6% solar cells stabilized at about 9%); fabricated wide-bandgap a-Si top cells, the highest Voc achieved for the single-junction top cell was 1.02 V, and top cells with high FF (up to 74%) were fabricated routinely; fabricated high-quality narrow-bandgap a-SiGe solar cells with 8.3% efficiency; found that bandgap-graded buffer layers improve the performance (Voc and FF) of the narrow-bandgap a-SiGe bottom cells; and found that a small amount of oxygen partial pressure ({approximately}2 {times} 10{sup {minus}5} torr) was beneficial for growing high-quality films from ITO targets.

Compaan, A. D.; Deng, X.; Bohn, R. G.

2000-01-04T23:59:59.000Z

86

The Importance of Domain Size and Purity in High-Efficiency Organic...  

NLE Websites -- All DOE Office Websites (Extended Search)

Solar Cells Print Wednesday, 27 March 2013 00:00 The efficiency of polymerorganic photovoltaic cells hinges on excitons-electronhole pairs energized by sunlight-getting to the...

87

Low-cost, high-efficiency solar cells utilizing GaAs-on-Si technology  

DOE Green Energy (OSTI)

This report describes work to develop technology to deposit GaAs on Si using a nucleation layer of atomic-layer-epitaxy-grown GaAs or AlAs on Si. This ensures two-dimensional nucleation and should lead to fewer defects in the final GaAs layer. As an alternative, we also developed technology for depositing GaAs on sawtooth-patterned Si. Preliminary studies showed that this material can have a very low defect density, [approximately] 1 [times] 10[sup 5] cm[sup [minus]5], as opposed to our conventionally grown GaAs on SL which has a typical defect density of over 1 [times]10[sup 7] cm[sup [minus]2]. Using these two now methods of GaAs-on-Si material growth, we made solar cells that are expected to show higher efficiencies than those of previous cells.

Vernon, S.M. (Spire Corp., Bedford, MA (United States))

1993-04-01T23:59:59.000Z

88

High-efficiency one-sun photovoltaic module demonstration using solar-grade CZ silicon. Final report  

DOE Green Energy (OSTI)

This work was performed jointly by Sandia National Laboratories (Albuquerque, NM) and Siemens Solar Industries (Camarillo, CA) under a Cooperative Research and Development Agreement (CRADA 1248). The work covers the period May 1994 to March 1996. The purpose of the work was to explore the performance potential of commercial, photovoltaic-grade Czochralski (Cz) silicon, and to demonstrate this potential through fabrication of high-efficiency cells and a module. Fabrication of the module was omitted in order to pursue further development of advanced device structures. The work included investigation of response of the material to various fabrication processes, development of advanced cell structures using the commercial material, and investigation of the stability of Cz silicon solar cells. Some important achievements of this work include the following: post-diffusion oxidations were found to be a possible source of material contamination; bulk lifetimes around 75 pts were achieved; efficiencies of 17.6% and 15.7% were achieved for large-area cells using advanced cell structures (back-surface fields and emitter wrap-through); and preliminary investigations into photodegradation in Cz silicon solar cells found that oxygen thermal donors might be involved. Efficiencies around 20% should be possible with commercial, photovoltaic-grade silicon using properly optimized processes and device structures.

Gee, J.M.

1996-10-01T23:59:59.000Z

89

Development of high efficiency (14%) solar cell array module. Third quarterly report, July 15, 1979-November 15, 1979  

DOE Green Energy (OSTI)

Most effort was concentrated on development of procedures to provide large area (3'' diameter) high efficiency (approx. 15.5% AM1, 28/sup 0/C) P/N solar cells. These efficiencies had been obtained for 2 x 2 cm area cells, but tests showed that the problem was not reduced silicon quality near the edges of the larger slices. The problems were in optimizing the back-surface field (BSF) process, and its possible interaction with the shallow P+ layer formation. Towards the end of this reporting period a promising process sequence had been identified and is being tested. The module design has been finalized. One hundred and twenty (120) cells will be connected eight (8) in parallel and fifteen (15) in series. The designs and tooling phases have been completed and are awaiting completion of the cells.

Iles, P.A.; Khemthong, S.; Olah, S.; Sampson, W.J.; Ling, K.S.

1980-01-01T23:59:59.000Z

90

Technology Development for High-Efficiency Solar Cells and Modules Using Thin (<80 um) Single-Crystal Silicon Wafers Produced by Epitaxy: June 11, 2011 - April 30, 2013  

DOE Green Energy (OSTI)

Final technical progress report of Crystal Solar subcontract NEU-31-40054-01. The objective of this 18-month program was to demonstrate the viability of high-efficiency thin (less than 80 um) monocrystalline silicon (Si) solar cells and modules with a low-cost epitaxial growth process.

Ravi, T. S.

2013-05-01T23:59:59.000Z

91

High-Efficiency CdTe and CIGS Thin-Film Solar Cells: Highlights and Challenges  

Science Conference Proceedings (OSTI)

Thin-film photovoltaic (PV) modules of CdTe and Cu(In,Ga)Se{sub 2} (CIGS) have the potential to reach cost-effective PV-generated electricity. These technologies have transitioned from the laboratory to the market place. Pilot production and first-time manufacturing are ramping up to higher capacity and enjoying a flood of venture-capital funding. CIGS solar cells and modules have achieved 19.5% and 13% efficiencies, respectively. Likewise, CdTe cells and modules have reached 16.5% and 10.2% efficiencies, respectively. Even higher efficiencies from the laboratory and from the manufacturing line are only a matter of time. Manufacturing-line yield continues to improve and is surpassing 85%. Long-term stability has been demonstrated for both technologies; however, some failures in the field have also been observed, emphasizing the critical need for understanding degradation mechanisms and packaging options. These two thin-film technologies have a common device/module structure: substrate, base electrode, absorber, junction layer, top electrode, patterning steps for monolithic integration, and encapsulation. The monolithic integration of thin-film solar cells can lead to significant manufacturing cost reduction compared to crystalline Si technology. The CdTe and CIGS modules share common structural elements. In principle, this commonality should lead to similar manufacturing cost per unit area, and thus, the module efficiency becomes the discriminating factor that determines the cost per watt. The long-term potential of the two technologies require R&D emphasis on science and engineering-based challenges to find solutions to achieve targeted cost-effective module performance, and in-field durability. Some of the challenges are common to both, e.g., in-situ process control and diagnostics, thinner absorber, understanding degradation mechanisms, protection from water vapor, and innovation in high-speed processing and module design. Other topics are specific to the technology, such as lower-cost and fast-deposition processes for CIGS, and improved back contact and voltage for CdTe devices.

Noufi, R.; Zweibel, K.

2006-01-01T23:59:59.000Z

92

Plasma analysis and diagnostics for high efficiency amorphous solar cell production. Final report  

DOE Green Energy (OSTI)

This is a project that sought to improve the amorphous silicon-germanium (SiGe) thin film deposition process in the production of solar cells. To accomplish this, the electron cyclotron resonance (ECR) plasma discharge, employed for the thin film deposition, was modified. Changes in the parameters of the plasma were monitored with diagnostic techniques, similar to those used in fusion plasma studies. That was the primary contribution from ORNL. Only one phase was contained in the statement of work, with the following tasks: (1) Develop a detailed program for plasma characterization. (2) Carry-out plasma modeling and analysis to support deposition systems design. (3) Operate experimental deposition systems for the purpose of plasma characterization. (4) Analyze data. (5) Modify deposition as directed by measurements. (6) This final report, which was deemed to be the only deliverable of this small project. And while the modified ECR discharge did not show measurable improvement of the conditions relevant to the deposition process, much was learned about the plasma parameters in the process. Some ideas on alternative designs are being discuss and funding options for testing such designed are being sought.

Klepper, C.C.

1994-12-21T23:59:59.000Z

93

Simulation and analysis of high efficiency absorption systems for solar cooling  

DOE Green Energy (OSTI)

A flexible modular computer code was developed for simulation of absorption systems. The code is capable to investigate, on a comparable basis, various cycles configurations with a variety of working fluids. In Phase 1 of the program, two open cycle absorption systems for solar energy were successfully simulated. Modifications which were applied to the code in Phase 2, allowed the analysis of systems with volatile absorbents, as used in advanced, high COP, absorption systems such as the GAX cycle. Ammonia-water database was developed into equation form and introduced to the code. That eliminated discontinuities in evaluating differentials used in the solver. Properties calculated with these equations fit well the tabulated data. This and other modifications allowed to model absorption cycles using ammonia-water. Single effect cycles converged in most ranges. Direct analysis of the code to advanced cycles, such as GAX, still encountered some convergence problems. It was, however, possible to analyze the GAX cycle in groups. The results show that high COP's are obtainable and are compatible with those reached by LBL. The properties of two additional pairs, that were developed in BG Univ., are reported. 27 refs., 13 figs., 13 tabs.

Shavit, A.; Haim, I. (Technion-Israel Inst. of Tech., Haifa (Israel). Faculty of Mechanical Engineering); Borde, I.; Jelinek, M. (Ben-Gurion Univ. of the Negev, Beersheba (Israel). Applied Research Inst.)

1989-05-31T23:59:59.000Z

94

High efficiency organic photovoltaic cells employing hybridized mixed-planar heterojunctions  

DOE Patents (OSTI)

A device is provided, having a first electrode, a second electrode, and a photoactive region disposed between the first electrode and the second electrode. The photoactive region includes a first organic layer comprising a mixture of an organic acceptor material and an organic donor material, wherein the first organic layer has a thickness not greater than 0.8 characteristic charge transport lengths, and a second organic layer in direct contact with the first organic layer, wherein: the second organic layer comprises an unmixed layer of the organic acceptor material or the organic donor material of the first organic layer, and the second organic layer has a thickness not less than about 0.1 optical absorption lengths. Preferably, the first organic layer has a thickness not greater than 0.3 characteristic charge transport lengths. Preferably, the second organic layer has a thickness of not less than about 0.2 optical absorption lengths. Embodiments of the invention can be capable of power efficiencies of 2% or greater, and preferably 5% or greater.

Xue, Jiangeng; Uchida, Soichi; Rand, Barry P; Forrest, Stephen

2013-11-19T23:59:59.000Z

95

High efficiency thin-film GaAs solar cells. First interim report, March 1--August 30, 1977  

DOE Green Energy (OSTI)

The objective is to demonstrate the feasibility of producing high-efficiency (15% or greater) thin-film GaAs solar cells with costs suitable for terrestrial solar electric power generation. The approach is that of growing GaAs by organio-metallic chemical vapor deposition on recrystallized germanium (Ge) films previously deposited on metal substrates and fabricating AMOS (Antireflecting Metal-Oxide-Semiconductor) solar cells on the GaAs. Previously it had been determined that a water vapor-grown native oxide (temperature = 25/sup 0/C) was the most useful native oxide for AMOS cells. A new chemical surface preparation prior to oxide growth led to more uniform oxides and reduced interface contamination, yielding lower reverse saturation current densities, a near-unity diode ideality factor, and better reproducibility. Substituting silver (Ag) for gold metallization showed no change in starting cell efficiency, but did greatly improve high temperature stability of the AMOS solar cell. A new study was completed on antireflection coatings on AMOS GaAs solar cells, taking into account the spectral response of the cell and nature of the solar spectra, and the results submitted for publication. XPS (X-ray Photoelectron Spectroscopy) studies had found earlier that the more efficient native oxides had primarily As/sub 2/O/sub 3/ and Ga/sub 2/O/sub 3/ with little GaAsO/sub 4/. A new chemical step etching was developed which can be used to profile the oxide in 5- to 7-A/sup 0/ steps without modifying the oxide chemistry as does ion sputtering. A new Schottky barrier structure is described which can give cell efficiencies up to 16% without oxide interfacial layer effects and 20 to 22% with a moderate interfacial layer effect. AMOS solar cells fabricated on sliced polycrystalline GaAs wafers with 100- to 500-..mu..m grains using Sb/sub 2/O/sub 3/ deposited oxides showed 14% cell efficiency compared to 16.2% in a region with few grains.

Stirn, R.J.

1977-12-01T23:59:59.000Z

96

High efficiency cadmium and zinc telluride-based thin film solar cells  

DOE Green Energy (OSTI)

Polycrystalline Cd{sub 1-x}Zn{sub x}Te and Cd{sub 1-x}Mn{sub x}Te films with a band gap of 1.7 eV were successfully grown on glass/SnO{sub 2}/CdS substrates by molecular beam epitaxy (MBE) and metal-organic chemical vapor deposition (MOCVD), respectively. Polycrystalline Cd{sub 1-x}Zn{sub x}Te films grown by MBE resulted in uniform composition and sharp interfaces. However, polycrystalline Cd{sub 1-x}Mn{sub x}Te films grown by MOCVD showed nonuniform compositions and evidence of manganese accumulation at the Cd{sub 1-x}Mn{sub x}Te/CdS interface. We found that manganese interdiffuses and replaces cadmium in the CdS film. By improving the CdTe/CdS interface and, thus, reducing the collection function effects, the efficiency of the MOCVD CdTe cell can be improved to about 13.5%. MBE-grown CdTe cells also produced 8%--9% efficiencies. The standard CdTe process was not optimum for ternary films and resulted in a decrease in the band gap. Recent results indicate that CdCl{sub 2} + ZnCl{sub 2} chemical treatment may prevent the band-gap reduction, and that chromate etch (rather than bromine etch) may provide the solution to contact resistance in the ternary cells.

Rohatgi, A.; Summers, C.J.; Erbil, A.; Sudharsanan, R.; Ringel, S. (Georgia Inst. of Tech., Atlanta, GA (USA). School of Electrical Engineering)

1990-10-01T23:59:59.000Z

97

Silicon sheet with molecular beam epitaxy for high efficiency solar cells. Final technical report, March 22, 1982-April 30, 1984  

DOE Green Energy (OSTI)

A two-year program has been carried out for the Jet Propulsion Laboratory in which the UCLA silicon MBE facility has been used to attempt to grow silicon solar cells of high efficiency. MBE ofers the potential of growing complex and arbitrary doping profiles with 10 A depth resolution. It is the only technique taht can readily grow built-in front and back surface fields of any desired depth and value in silicon solar cells, or the more complicated profiles needed for a double junction cascade cell, all in silicon, connected in series by a tunnel junction. Although the dopant control required for such structures has been demonstrated in silicon by UCLA, crystal quality at the p-n junctions is still too poor to allow the other advantages to be exploited. Results from other laboratories indicate that this problem will soon be overcome. A computer analysis of the double cascade all in silicon shows that efficiencies can be raised over that of any single silicon cell by 1 or 2%, and that open circuit voltage of almost twice that of a single cell should be possible.

Not Available

1984-01-01T23:59:59.000Z

98

Development of high-efficiency solar cells on silicon web. First quarterly progress report, April 20-July 15, 1984  

DOE Green Energy (OSTI)

The major objective of the work reported is to improve web base material with a goal toward obtaining solar cell efficiencies in excess of 18% (AM1). The program consists of the investigation of carrier loss mechanisms in web silicon, development of techniques to reduce carrier recombination in web, and web cell fabrication using effective surface passivation. Web surfaces have been bevelled with the intention of measuring the electrical activity of the twin plane. Web crystals have been intentionally contaminated with vanadium and titanium to examine the twin-plane-assisted internal gettering by DLTS. Model calculations were done to see the effect of twin-plane activity on V/sub oc/ as a function of resistivity of the web material. Experiments were initiated to study the effect of heat treatment and gettering on the minority carrier diffusion length in webs. Fabrication of high-efficiency web cells using several web crystals was initiated. These cells will include surface passivation and double-layer antireflection coating. (LEW)

Rohatgi, A.; Meier, D.L.; Campbell, R.B.; Rai-Choudhury, P.

1984-08-09T23:59:59.000Z

99

High Efficiency Thin Film CdTe and a-Si Based Solar Cells: Final Technical Report, 4 March 1998--15 October 2001  

DOE Green Energy (OSTI)

This is the final report covering about 42 months of this subcontract for research on high-efficiency CdTe-based thin-film solar cells and on high-efficiency a-Si-based thin-film solar cells. Phases I and II have been extensively covered in two Annual Reports. For this Final Report, highlights of the first two Phases will be provided and then detail will be given on the last year and a half of Phase III. The effort on CdTe-based materials is led by Prof. Compaan and emphasizes the use of sputter deposition of the semiconductor layers in the fabrication of CdS/CdTe cells. The effort on high-efficiency a-Si materials is led by Prof. Deng and emphasizes plasma-enhanced chemical vapor deposition for cell fabrication with major efforts on triple-junction devices.

Compaan, A. D.; Deng, X.; Bohn, R. G.

2003-10-01T23:59:59.000Z

100

Efficient CO2 Fixation Pathways: Energy Plant: High Efficiency Photosynthetic Organisms  

SciTech Connect

PETRO Project: UCLA is redesigning the carbon fixation pathways of plants to make them more efficient at capturing the energy in sunlight. Carbon fixation is the key process that plants use to convert carbon dioxide (CO2) from the atmosphere into higher energy molecules (such as sugars) using energy from the sun. UCLA is addressing the inefficiency of the process through an alternative biochemical pathway that uses 50% less energy than the pathway used by all land plants. In addition, instead of producing sugars, UCLA’s designer pathway will produce pyruvate, the precursor of choice for a wide variety of liquid fuels. Theoretically, the new biochemical pathway will allow a plant to capture 200% as much CO2 using the same amount of light. The pathways will first be tested on model photosynthetic organisms and later incorporated into other plants, thus dramatically improving the productivity of both food and fuel crops.

None

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "high-efficiency organic solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Highly Efficient 32.3% Monolithic GaInP/GaAs/Ge Triple Junction Concentrator Solar Cells  

DOE Green Energy (OSTI)

Based on recent cell improvements for space applications, multijunction cells apear to be ideal candidates for high efficiency, cost effective, PV concentrator systems.

Cotal, H. L.; Lillington, D. R.; Ermer, J. H.; King, R. R.; Karam, N. H.; Kurtz, S. R.; Friedman, D. J.; Olson, J. M.; Ward, S.; Duda, A.; Emery, K. A.; Moriarty, T.

2000-01-01T23:59:59.000Z

102

Highly efficient blue organic light emitting devices with indium-free transparent anode on flexible substrates  

Science Conference Proceedings (OSTI)

Indium-free transparent conducting oxides may provide a lower cost solution for the transparent anode in flexible displays and energy efficient solid state lighting. We report herein a near room temperature sputtering process for generating an indium-free transparent conductive oxide (TCO) coating on a flexible substrate. Specifically, we deposited gallium-doped zinc oxide (GZO) uniformly over a 12” diameter area at room temperature on polyethylene terephthalate (PET). During deposition, the system heats to about 60oC due to the energetic sputtering conditions, without any noticeable damage to the PET substrate. The GZO films exhibit excellent physical, optical and electrical properties: roughness ~7 nm, transmittance >85% and resistivity ~ 10-3 ohm• cm. Phosphorescent blue organic light-emitting devices (OLEDs) were fabricated on these substrates with comparable performance (16% external quantum efficiency and 33 lm/W power efficiency at 1mA/cm2) to that of devices fabricated on GZO (or ITO) deposited on glass substrates, suggesting flexible GZO/PET substrates may be used instead of high-cost and rigid ITO and glass for flexible displays and solid state lighting.

Wang, Liang; Swensen, James S.; Polikarpov, Evgueni; Matson, Dean W.; Bonham, Charles C.; Bennett, Wendy D.; Gaspar, Daniel J.; Padmaperuma, Asanga B.

2010-09-30T23:59:59.000Z

103

Research on the basic understanding of high efficiency in silicon solar cells. Annual report, 1 December 1982-30 November 1983  

DOE Green Energy (OSTI)

This report presents results of research designed to develop a basic understanding of high-efficiency silicon solar cells and achieve cell efficiencies greater than 17% by employing innovative concepts of material preparation, cell design, and fabrication technology. The research program consisted of a theoretical effort to develop models for very high-efficiency cell designs, experimental verification of the designs, and improved understanding of efficiency-limiting mechanisms such as heavy doping effects and bulk and surface recombination. Research was performed on high-lifetime float-zone silicon, the baseline materials, low-resistivity gallium-doped czochralski silicon, and boron-doped float-zone silicon.

Rohatgi, A.; Rai-Choudhury, P.

1984-09-01T23:59:59.000Z

104

Extraction of semivolatile organic compounds from high-efficiency particulate air (HEPA) filters by supercritical carbon dioxide  

SciTech Connect

Supercritical fluid extraction (SFE) using unmodified carbon dioxide has been explored as an alternative method for the extraction of semivolatile organic compounds from high-efficiency particulate air (HEPA) filters. HEPA filters provide the final stage of containment on many exhaust systems in US Department of Energy (DOE) facilities by preventing the escape of chemical and radioactive materials entrained in the exhausted air. The efficiency of the filters is tested by the manufacturer and DOE using dioctylphthalate (DOP), a substance regulated by the US Environmental Protection Agency under the Resource Conservation and Recovery Act. Therefore, the filters must be analyzed for semivolatile organics before disposal. Ninety-eight acid, base, and neutral semivolatile organics were spiked onto blank HEPA material and extracted using SFE, Soxhlet, automated Soxhlet, and sonication techniques. The SFE conditions were optimized using a Dionex SFE-703 instrument. Average recoveries for the 98 semivolatile compounds are 82.7% for Soxhlet, 74.0% for sonication, 70.2% for SFE, and 62.9% for Soxtec. Supercritical fluid extraction reduces the extraction solvent volume to 10--15 mL, a factor of 20--30 less than Soxhlet and more than 5 times less than Soxtec and sonication. Extraction times of 30--45 min are used compared to 16--18 h for Soxhlet extraction.

Schilling, J.B.

1997-09-01T23:59:59.000Z

105

High Efficiency and High Rate Deposited Amorphous Silicon-Based Solar Cells: Final Technical Report, 1 September 2001--6 March 2005  

SciTech Connect

The objectives for the University of Toledo are to: (1) establish a transferable knowledge and technology base for fabricating high-efficiency triple-junction a-Si-based solar cells, and (2) develop high-rate deposition techniques for the growing a-Si-based and related alloys, including poly-Si, c-Si, a-SiGe, and a-Si films and photovoltaic devices with these materials.

Deng, X.

2006-01-01T23:59:59.000Z

106

New concepts for high efficiency energy conversion: The avalanche heterostructure and superlattice solar cells. Subcontract report, 1 June 1987--31 January 1990  

DOE Green Energy (OSTI)

This report describes investigation into the theory and technology of a novel heterojunction or superlattice, single-junction solar cell, which injects electrons across the heterointerface to produce highly efficient impact ionization of carriers in the lowband-gap side of the junction, thereby conserving their total energy. Also, the superlattice structure has the advantage of relaxing the need for perfect lattice matching at the p-n interface and will inhibit the cross diffusion of dopant atoms that typically occurs in heavy doping. This structure avoids the use of tunnel junctions that make it very difficult to achieve the predicted efficiencies in cascade cells, thus making it possible to obtain energy efficiencies that are competitive with those predicted for cascade solar cells with reduced complexity and cost. This cell structure could also be incorporated into other solar cell structures designed for wider spectral coverage.

Summers, C.J.; Rohatgi, A.; Torabi, A.; Harris, H.M. [Georgia Tech Research Inst., Atlanta, GA (United States)

1993-01-01T23:59:59.000Z

107

Ultra High Efficiency Thermo-Photovoltaic Solar Cells Using Metallic Photonic Crystals As Intermediate Absorber and Emitter  

E-Print Network (OSTI)

, a material with a high melting point, since many solar thermal applications, especially solar thermal photovolatics,6,7 require absorbers that can withstand high temperatures. While there is significant amount-difference time-domain method.15 To describe the effect of material dispersion and absorption in the time

Nur, Amos

108

High-Efficiency Neutron Detection and Spectroscopy  

Science Conference Proceedings (OSTI)

High-Efficiency Neutron Detection and Spectroscopy. ... such as searches for WIMP dark matter, neutrinoless double beta decay, and solar neutrinos. ...

2013-07-22T23:59:59.000Z

109

The Growth of InGaAsN for High Efficiency Solar Cells by Metalorganic Chemical Vapor Deposition  

SciTech Connect

InGaAsN alloys are a promising material for increasing the efficiency of multi-junction solar cells now used for satellite power systems. However, the growth of these dilute N containing alloys has been challenging with further improvements in material quality needed before the solar cell higher efficiencies are realized. Nitrogen/V ratios exceeding 0.981 resulted in lower N incorporation and poor surface morphologies. The growth rate was found to depend on not only the total group III transport for a fixed N/V ratio but also on the N/V ratio. Carbon tetrachloride and dimethylzinc were effective for p-type doping. Disilane was not an effective n-type dopant while SiCl4 did result in n-type material but only a narrow range of electron concentrations (2-5e17cm{sup -3}) were achieved.

ALLERMAN,ANDREW A.; BANKS,JAMES C.; GEE,JAMES M.; JONES,ERIC D.; KURTZ,STEVEN R.

1999-09-16T23:59:59.000Z

110

High-Efficiency Amorphous Silicon Alloy Based Solar Cells and Modules; Final Technical Progress Report, 30 May 2002--31 May 2005  

DOE Green Energy (OSTI)

The principal objective of this R&D program is to expand, enhance, and accelerate knowledge and capabilities for development of high-efficiency hydrogenated amorphous silicon (a-Si:H) and amorphous silicon-germanium alloy (a-SiGe:H) related thin-film multijunction solar cells and modules with low manufacturing cost and high reliability. Our strategy has been to use the spectrum-splitting triple-junction structure, a-Si:H/a-SiGe:H/a-SiGe:H, to improve solar cell and module efficiency, stability, and throughput of production. The methodology used to achieve the objectives included: (1) explore the highest stable efficiency using the triple-junction structure deposited using RF glow discharge at a low rate, (2) fabricate the devices at a high deposition rate for high throughput and low cost, and (3) develop an optimized recipe using the R&D batch large-area reactor to help the design and optimization of the roll-to-roll production machines. For short-term goals, we have worked on the improvement of a-Si:H and a-SiGe:H alloy solar cells. a-Si:H and a-SiGe:H are the foundation of current a-Si:H based thin-film photovoltaic technology. Any improvement in cell efficiency, throughput, and cost reduction will immediately improve operation efficiency of our manufacturing plant, allowing us to further expand our production capacity.

Guha, S.; Yang, J.

2005-10-01T23:59:59.000Z

111

Organic Solar Cells: Absolute Measurement of Domain Composition...  

NLE Websites -- All DOE Office Websites (Extended Search)

Organic Solar Cells: Absolute Measurement of Domain Composition and Nanoscale Size Distribution Explains Performance in Solar Cells Organic Solar Cells: Absolute Measurement of...

112

High-Efficiency CdTe and CIGS Thin-Film Solar Cells: Highlights and Challenges; Preprint  

DOE Green Energy (OSTI)

Thin-film photovoltaic (PV) modules of CdTe and Cu(In,Ga)Se2 (CIGS) have the potential to reach cost-effective PV-generated electricity. These technologies have transitioned from the laboratory to the market place. Pilot production and first-time manufacturing are ramping up to higher capacity and enjoying a flood of venture-capital funding. CIGS solar cells and modules have achieved 19.5% and 13% efficiencies, respectively. Likewise, CdTe cells and modules have reached 16.5% and 10.2% efficiencies, respectively. Even higher efficiencies from the laboratory and from the manufacturing line are only a matter of time. Manufacturing-line yield continues to improve and is surpassing 85%. Long-term stability has been demonstrated for both technologies; however, some failures in the field have also been observed, emphasizing the critical need for understanding degradation mechanisms and packaging options. The long-term potential of the two technologies require R&D emphasis on science and engineering-based challenges to find solutions to achieve targeted cost-effective module performance, and in-field durability. Some of the challenges are common to both, e.g., in-situ process control and diagnostics, thinner absorber, understanding degradation mechanisms, protection from water vapor, and innovation in high-speed processing and module design. Other topics are specific to the technology, such as lower-cost and fast-deposition processes for CIGS, and improved back contact and voltage for CdTe devices.

Noufi, R.; Zweibel, K.

2006-05-01T23:59:59.000Z

113

Growth and development of GaInAsP for use in high-efficiency solar cells. Final subcontract report, 1 July 1991--30 December 1993  

DOE Green Energy (OSTI)

This report describes accomplishments during Phase 3 of this subcontract. The overall goals of the subcontract were (1) to develop the necessary technology to grow high-efficiency GaInAsP layers that are lattice-matched to GaAs and Ge; (2) to demonstrate highefficiency GaInAsP single-junction solar cells; and (3) to demonstrate GaInAsP/Ge cascade solar cells suitable for operation under concentrated (500X) sunlight. The major accomplishments during Phase 3 include (1) demonstrating a GaInAsP tunnel diode for use as an interconnect in the GaInAsP/Ge cascade cell, and (2) demonstrating a GaInAsP/Ge cascade cell. The development of the GaInAsP tunnel diode is a major accomplishment because it allows for the GaInAsP and Ge cells to be connected without optical losses for the bottom Ge cell, such as a Ge tunnel diode would cause. The GaInAsP/Ge cascade cell development is significant because of the demonstration of a cascade cell with a new materials system.

Sharps, P.R. [Research Triangle Inst., Research Triangle Park, NC (United States)

1994-10-01T23:59:59.000Z

114

Very high efficiency photovoltaic cells based on fully organic multiple quantum wells. Quarterly technical progress report, 15 February 1995--15 May 1995  

DOE Green Energy (OSTI)

The principal project objective is to demonstrate relatively high solar conversion efficiency using extremely low-cost, thin-film technology based on crystalline organic multiple quantum well (MQW) photovoltaic cells. The authors base their work on recent observations both in the laboratory and elsewhere that have indicated the quantum efficiency of organic photoconductors based on vacuum-deposited thin films can be increased by at least two orders of magnitude (to at least 10%) if the organic films are grown in a highly ordered manner, and if organic multiple quantum wells are used in the absorption region. The authors are investigating the physical origin of this phenomenon, and they are growing thin-film MQW cells that demonstrate relatively high quantum efficiencies to determine the practicality of crystalline organic thin-film cells for solar power applications. The investigations are based on a unique, ultrahigh-vacuum organic molecular beam deposition system in the laboratory.

Forrest, S.R. [Princeton Univ., NJ (United States)

1997-03-01T23:59:59.000Z

115

High-efficiency photovoltaic cells  

DOE Patents (OSTI)

High efficiency solar converters comprised of a two cell, non-lattice matched, monolithic stacked semiconductor configuration using optimum pairs of cells having bandgaps in the range 1.6 to 1.7 eV and 0.95 to 1.1 eV, and a method of fabrication thereof, are disclosed. The high band gap subcells are fabricated using metal organic chemical vapor deposition (MOCVD), liquid phase epitaxy (LPE) or molecular beam epitaxy (MBE) to produce the required AlGaAs layers of optimized composition, thickness and doping to produce high performance, heteroface homojunction devices. The low bandgap subcells are similarly fabricated from AlGa(As)Sb compositions by LPE, MBE or MOCVD. These subcells are then coupled to form a monolithic structure by an appropriate bonding technique which also forms the required transparent intercell ohmic contact (IOC) between the two subcells. Improved ohmic contacts to the high bandgap semiconductor structure can be formed by vacuum evaporating to suitable metal or semiconductor materials which react during laser annealing to form a low bandgap semiconductor which provides a low contact resistance structure.

Yang, H.T.; Zehr, S.W.

1982-06-21T23:59:59.000Z

116

Fabrication and Characterization of Organic Solar Cells  

E-Print Network (OSTI)

treatment  of  indium  tin  oxide  for  organic solar JR.  Criteria for ITO (indium?tin?oxide) an organic  light expansive material, indium thin oxide (ITO) thin films, with

Yengel, Emre

2010-01-01T23:59:59.000Z

117

High efficiency diamond solar cells  

SciTech Connect

A photovoltaic device and method of making same. A layer of p-doped microcrystalline diamond is deposited on a layer of n-doped ultrananocrystalline diamond such as by providing a substrate in a chamber, providing a first atmosphere containing about 1% by volume CH.sub.4 and about 99% by volume H.sub.2 with dopant quantities of a boron compound, subjecting the atmosphere to microwave energy to deposit a p-doped microcrystalline diamond layer on the substrate, providing a second atmosphere of about 1% by volume CH.sub.4 and about 89% by volume Ar and about 10% by volume N.sub.2, subjecting the second atmosphere to microwave energy to deposit a n-doped ultrananocrystalline diamond layer on the p-doped microcrystalline diamond layer. Electrodes and leads are added to conduct electrical energy when the layers are irradiated.

Gruen, Dieter M. (Downers Grove, IL)

2008-05-06T23:59:59.000Z

118

Research on high-efficiency, single-junction, monolithic, thin-film amorphous silicon solar cells: Phase II annual subcontract report, 1 January 1985--31 January 1986  

DOE Green Energy (OSTI)

This report presents results of the second phase of research on high-efficiency, single-junction, monolithic, thin-film a-Si solar cells. Five glow-discharge deposition systems, including a new in-line, multichamber system, were used to grow both doped and undoped a-Si:H. A large number of silane and disilane gas cylinders were analyzed with a gas chromatography/mass spectroscopy system. Strong correlations were found between the breakdown voltage, the deposition rate, the diffusion length, and the conversion efficiency for varying cathode-anode separations in a DC glow-discharge deposition mode. Tin oxide films were grown by chemical vapor deposition with either tetramethyl tin (TMT) or tin tetrachloride (TTC). The best were grown with TMT, but TTC films had a more controlled texture for light trapping and provided a better contact to the p-layer. The best results were obtained with 7059 glass substrates. Efficiencies as high as 10.86% were obtained in p-i-n cells with superlattice p-layers and as high as 10.74% in cells with both superlattice p- and n-layers. Measurements showed that the boron-doping level in the p-layer can strongly affect transport in the i-layer, which can be minimized by reactive flushing before i-layer deposition. Stability of a-Si:H cells is improved by light doping. 51 refs., 64 figs., 21 tabs.

Carlson, D.E.; Ayra, R.R.; Bennett, M.S.; Catalano, A.; D'Aiello, R.V.; Dickson, C.R.; McVeigh, J.; Newton, J.; O'Dowd, J.; Oswald, R.S.; Rajan, K.

1988-09-01T23:59:59.000Z

119

Advanced high efficiency concentrator cells  

DOE Green Energy (OSTI)

This report describes research to develop the technology needed to demonstrate a monolithic, multijunction, two-terminal, concentrator solar cell with a terrestrial power conversion efficiency greater than 35%. Under three previous subcontracts, Varian developed many of the aspects of a technology needed to fabricate very high efficiency concentrator cells. The current project was aimed at exploiting the new understanding of high efficiency solar cells. Key results covered in this report are as follows. (1) A 1.93-eV AlGaAs/1.42-eV GaAs metal-interconnected cascade cell was manufactured with a one-sun efficiency at 27.6% at air mass 1.5 (AM1.5) global. (2) A 1.0eV InGaAs cell was fabricated on the reverse'' side of a low-doped GaAs substrate with a one-sun efficiency of 2.5% AM1.5 diffuse and a short-circuit current of 14.4 mA/cm{sup 2}. (3) Small-scale manufacturing of GaAs p/n concentrator cells was attempted and obtained an excellent yield of high-efficiency cells. (4) Grown-in tunnel junction cell interconnects that are transparent and thermally stable using C and Si dopants were developed. 10 refs.

Gale, R. (Varian Associates, Inc., Palo Alto, CA (United States). Varian Research Center)

1992-06-01T23:59:59.000Z

120

New Morphological Paradigm Uncovered in Organic Solar Cells  

NLE Websites -- All DOE Office Websites (Extended Search)

New Morphological Paradigm Uncovered in Organic Solar Cells Print Organic solar cells are made of light, flexible, renewable materials; they require simple and inexpensive...

Note: This page contains sample records for the topic "high-efficiency organic solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

HIGH EFFICIENCY SYNGAS GENERATION  

DOE Green Energy (OSTI)

This project investigated an efficient and low cost method of auto-thermally reforming natural gas to hydrogen and carbon monoxide. Reforming is the highest cost step in producing products such as methanol and Fisher Tropsch liquids (i.e., gas to liquids); and reducing the cost of reforming is the key to reducing the cost of these products. Steam reforming is expensive because of the high cost of the high nickel alloy reforming tubes (i.e., indirectly fired reforming tubes). Conventional auto-thermal or Partial Oxidation (POX) reforming minimizes the size and cost of the reformers and provides a near optimum mixture of CO and hydrogen. However POX requires pure oxygen, which consumes power and significantly increases the cost to reforming. Our high efficiency process extracts oxygen from low-pressure air with novel oxygen sorbent and transfers the oxygen to a nickel-catalyzed reformer. The syngas is generated at process pressure (typically 20 to 40 bar) without nitrogen dilution and has a 1CO to 2H{sub 2} ratio that is near optimum for the subsequent production of Fisher-Tropsch liquid to liquids and other chemicals (i.e., Gas to Liquids, GTL). Our high process efficiency comes from the way we transfer the oxygen into the reformer. All of the components of the process, except for the oxygen sorbent, are commonly used in commercial practice. A process based on a longlived, regenerable, oxygen transfer sorbent could substantially reduce the cost of natural gas reforming to syngas. Lower cost syngas (CO + 2H{sub 2}) that is the feedstock for GTL would reduce the cost of GTL and for other commercial applications (e.g., methanol, other organic chemicals). The vast gas resources of Alaska's North Slope (ANS) offer more than 22 Tcf of gas and GTL production in this application alone, and could account for as much as 300,000 to 700,000 bpd for 20 to 30+ years. We developed a new sorbent, which is an essential part of the High Efficiency Oxygen Process (HOP). We tested the sorbent and observed that it has both a good oxygen capacity and operates as a highly effective reforming catalyst. We conducted a long duration tests of the sorbent (1,500 hours of continuous operation in the HOP cycle). Although the sorbent lost some oxygen capacity with cycling, the sorbent oxygen capacity stabilized after 1,000 hours and remained constant to the end of the test, 1,500 hour. The activity of the catalyst to reform methane to a hydrogen and carbon monoxide mixture was unchanged through the oxidation/reduction cycling. Our cost and performance analyses indicated a significant reduction in the cost of GTL production when using the HOP process integrated into a GTL plant.

Robert J. Copeland; Yevgenia Gershanovich; Brian Windecker

2005-02-01T23:59:59.000Z

122

High-Efficiency Amorphous Silicon and Nanocrystalline Silicon Based Solar Cells and Modules: Annual Technical Progress Report, 30 January 2006 - 29 January 29, 2007  

DOE Green Energy (OSTI)

United Solar used a-Si:H/a-SiGe:H/a-SiGe:H in two manufacturing plants and improved solar efficiency and reduced manufacturing cost by new deposition methods, optimized deposition parameters, and new materials and cell structures.

Guha, S.; Yang, J.

2007-07-01T23:59:59.000Z

123

High efficiency solar air heaters with novel built-in heat storage for use in a humidification-dehumidification desalination cycle  

E-Print Network (OSTI)

Compared to solar water heaters, solar air heaters have received relatively little investigation and have resulted in few commercial products. However, in the context of a Humidification-Dehumidification (HD) Desalination ...

Summers, Edward K

2010-01-01T23:59:59.000Z

124

Controlled Structure of Organic-Nanomaterial Solar Cells - Energy ...  

Technology Marketing Summary Organic, polymer-based solar cells—lightweight alternatives to conventional, silicon-based solar cells—have great potential for ...

125

Testing of the Sunstove Organization`s Sunstove Solar Oven  

DOE Green Energy (OSTI)

A Sunstove Organization`s Sunstove was tested at Sandia`s Solar Thermal Test Facility. It was instrumented with five type K thermocouples to determine warm-up rates when empty and when a pot containing two liters of water was placed inside. It reached inside air temperatures above 115{degrees}C (240{degrees}F). It heated two liters of water from room temperature to 80{degrees}C (175{degrees}F) in about two hours. Observations were made on the cooling and reheating rates during a cloud passage. The adverse effects of wind on the operation of the solar oven were also noted.

Moss, T.A.

1997-03-01T23:59:59.000Z

126

High efficiency photoionization detector  

DOE Patents (OSTI)

A high efficiency photoionization detector is described using tetraaminoethylenes in a gaseous state having a low ionization potential and a relative photoionization cross section which closely matches the emission spectrum of xenon gas. Imaging proportional counters are also disclosed using the novel photoionization detector of the invention. The compound of greatest interest is TMAE which comprises tetrakis(dimethylamino)ethylene which has a measured ionization potential of 5.36 [+-] 0.02 eV, and a vapor pressure of 0.35 torr at 20 C. 6 figs.

Anderson, D.F.

1984-01-31T23:59:59.000Z

127

High efficiency photoionization detector  

DOE Patents (OSTI)

A high efficiency photoionization detector using tetraaminoethylenes in a gaseous state having a low ionization potential and a relative photoionization cross section which closely matches the emission spectrum of xenon gas. Imaging proportional counters are also disclosed using the novel photoionization detector of the invention. The compound of greatest interest is TMAE which comprises tetrakis(dimethylamino)ethylene which has a measured ionization potential of 5.36.+-.0.02 eV, and a vapor pressure of 0.35 torr at 20.degree. C.

Anderson, David F. (3055 Trinity, Los Alamos, NM 87544)

1984-01-01T23:59:59.000Z

128

Session V: Organic Photovoltaics and Photoelectrochemical Cells  

Science Conference Proceedings (OSTI)

Jun 23, 2011 ... V2, Improved High Efficiency Organic Solar Cells via Incorporation of .... in design are broad absorption spectrum and effective light absorption, ...

129

High-efficiency cadmium and zinc-telluride-based thin-film solar cells. Annual subcontract report, 1 March 1990--28 February 1991  

DOE Green Energy (OSTI)

This report describes research into polycrystalline CdTe solar cells grown by metal-organic chemical vapor deposition. Efficiencies of {approximately}10% were achieved using both p-i-n and p-n structures. A pre-heat treatment of CdS/SnO{sub 2}/glass substrates at 450{degrees}C in hydrogen atmosphere prior to the CdTe growth was found to be essential for high performance because this heat treatment reduces oxygen-related defects from the CdS surface. However, this treatment also resulted in a Cd-deficient CdS surface, which may in part limit the CdTe cell efficiency to 10% due to Cd vacancy-related interface defects. Preliminary model calculations suggest that removing these states can increase the cell efficiency from 10% to 13.5%. Photon absorption in the CdS film also limits the cell performance, and eliminating this loss mechanism can result in CdTe efficiencies in excess of 18%. Polycrystalline, 1.7-e, CdZnTe films were also grown for tandem-cell applications. CdZnTe/CdS cells processed using the standard CdTe cell fabrication procedure resulted in 4.4% efficiency, high series resistance, and a band-gap shift to 1.55 eV. The formation of Zn-O at and near the CdZnTe surface is the source of high contact resistance. A saturated dichromate each prior to contact deposition was found to solve the contact resistance problem. The CdCl{sub 2} treatment was identified as the cause of the observed band-gap shift due to the preferred formation of ZnCl{sub 2}. 59 refs.

Rohatgi, A.; Sudharsanan, R.; Ringel, S. [Georgia Inst. of Tech., Atlanta, GA (United States)

1992-02-01T23:59:59.000Z

130

High Efficiency, Clean Combustion  

DOE Green Energy (OSTI)

Energy use in trucks has been increasing at a faster rate than that of automobiles within the U.S. transportation sector. According to the Energy Information Administration (EIA) Annual Energy Outlook (AEO), a 23% increase in fuel consumption for the U.S. heavy duty truck segment is expected between 2009 to 2020. The heavy duty vehicle oil consumption is projected to grow between 2009 and 2050 while light duty vehicle (LDV) fuel consumption will eventually experience a decrease. By 2050, the oil consumption rate by LDVs is anticipated to decrease below 2009 levels due to CAFE standards and biofuel use. In contrast, the heavy duty oil consumption rate is anticipated to double. The increasing trend in oil consumption for heavy trucks is linked to the vitality, security, and growth of the U.S. economy. An essential part of a stable and vibrant U.S. economy is a productive U.S. trucking industry. Studies have shown that the U.S. gross domestic product (GDP) is strongly correlated to freight transport. Over 90% of all U.S. freight tonnage is transported by diesel power and over 75% is transported by trucks. Given the vital role that the trucking industry plays in the economy, improving the efficiency of the transportation of goods was a central focus of the Cummins High Efficient Clean Combustion (HECC) program. In a commercial vehicle, the diesel engine remains the largest source of fuel efficiency loss, but remains the greatest opportunity for fuel efficiency improvements. In addition to reducing oil consumption and the dependency on foreign oil, this project will mitigate the impact on the environment by meeting US EPA 2010 emissions regulations. Innovation is a key element in sustaining a U.S. trucking industry that is competitive in global markets. Unlike passenger vehicles, the trucking industry cannot simply downsize the vehicle and still transport the freight with improved efficiency. The truck manufacturing and supporting industries are faced with numerous challenges to reduce oil consumption and greenhouse gases, meet stringent emissions regulations, provide customer value, and improve safety. The HECC program successfully reduced engine fuel consumption and greenhouse gases while providing greater customer valve. The US EPA 2010 emissions standard poses a significant challenge for developing clean diesel powertrains that meet the DoE Vehicle Technologies Multi-Year Program Plan (MYPP) for fuel efficiency improvement while remaining affordable. Along with exhaust emissions, an emphasis on heavy duty vehicle fuel efficiency is being driven by increased energy costs as well as the potential regulation of greenhouse gases. An important element of the success of meeting emissions while significantly improving efficiency is leveraging Cummins component technologies such as fuel injection equipment, aftertreatment, turbomahcinery, electronic controls, and combustion systems. Innovation in component technology coupled with system integration is enabling Cummins to move forward with the development of high efficiency clean diesel products with a long term goal of reaching a 55% peak brake thermal efficiency for the engine plus aftertreatment system. The first step in developing high efficiency clean products has been supported by the DoE co-sponsored HECC program. The objectives of the HECC program are: (1) To design and develop advanced diesel engine architectures capable of achieving US EPA 2010 emission regulations while improving the brake thermal efficiency by 10% compared to the baseline (a state of the art 2007 production diesel engine). (2) To design and develop components and subsystems (fuel systems, air handling, controls, etc) to enable construction and development of multi-cylinder engines. (3) To perform an assessment of the commercial viability of the newly developed engine technology. (4) To specify fuel properties conducive to improvements in emissions, reliability, and fuel efficiency for engines using high-efficiency clean combustion (HECC) technologies. To demonstrate the technology is compatible with B2

Donald Stanton

2010-03-31T23:59:59.000Z

131

Organic-Based ("Excitonic") Solar Cells  

Science Conference Proceedings (OSTI)

The existing types of organic-based solar cells, including dye-sensitized solar cells (DSSCs), can be categorized by their photoconversion mechanism as excitonic solar cells, XSCs. Their distinguishing characteristic is that charge generation and separation are simultaneous and this occurs via exciton dissociation at a heterointerface. Electrons are photogenerated on one side of the interface and holes on the other. This results in fundamental differences between XSCs and conventional PV cells. For example, the open circuit photovoltage, Voc, in conventional cells is limited to less than the magnitude of the band bending, bi; however, Voc in XSCs is commonly greater than bi. A general theoretical description is employed to quantify the differences between conventional and excitonic cells. The key difference is the dominant importance, in XSCs, of the photoinduced chemical potential energy gradient, ..delta..hn, whereas ..delta..hn is unimportant, and therefore neglected, in theoretical descriptions of conventional PV cells. Several examples are provided.

Gregg. B.A.

2003-05-01T23:59:59.000Z

132

Research on high-efficiency, single-junction, monolithic, thin-film amorphous silicon solar cells: Annual subcontract report, May 1985 - Jul 1986  

DOE Green Energy (OSTI)

A study was undertaken of the optoelectronic properties of amorphous silicon-hydrogen thin films deposited from disilane at high deposition rates. The information derived from this study was used to fabricate amorphous silicon solar cells with efficiencies exceeding 7%. The intrinsic layer of these solar cells was deposited at 15 angstroms/second. Material properties investigated included dark conductivity, photoconductivity, minority carrier diffusion length, and density of states. The solar cells properties characterized were absolute quantum yield and simulated global AM 1.5 efficiencies. Investigations were undertaken utilizing optical and infrared spectroscopy to optimize the microstructures of the intrinsic amorphous silicon. That work was sponsored by the New York State Energy Research and Development Authority. The information was used to optimize the intrinsic layer of amorphous silicon solar cells, resulting in AM 1.5 efficiencies exceeding 7%.

Wiesmann, H.; Dolan, J.; Fricano, G.; Danginis, V.

1987-02-01T23:59:59.000Z

133

Highly efficient blue organic light emitting device using indium-free transparent anode Ga:ZnO with scalability for large area coating  

Science Conference Proceedings (OSTI)

The availability of economically-produced and environmentally-stable transparent conductive oxide (TCO) coatings is critical for the development of a variety of electronic devices requiring transparent electrodes. Such devices include liquid crystal display pixels and organic light emitting diodes (OLEDs),[1, 2] solar cell applications,[3, 4] and electrically heated windows.[5, 6] The materials fulfilling these requirements are usually wide band gap inorganic transparent conductive oxides (TCOs). Tin-doped indium oxide, or ITO, has traditionally been used for electronic TCO applications because of its low resistivity, high work function and transparency. Due to the increasing cost and limited supply of indium and its tendency to migrate in to the device, there has been increasing research interest to substitute ITO with an indium-free material. A number of alternative metal oxides and doped oxides have been evaluated as TCO materials with varying degrees of success.[7, 8] Among these alternatives to ITO, gallium-doped zinc oxide (GZO) [2, 9] and aluminium-doped zinc oxide (AZO) [10, 11] have drawn particular attention. These materials have been demonstrated to have resistivities and transparencies approaching those of the best ITO, low toxicity, and much lower materials cost. Although AZO is attractive as a TCO electrode material, GZO features a greater resistance to oxidation as a result of gallium’s greater electronegativity compared to Submitted to 2 aluminum.[12, 13

Wang, Liang (Frank); Matson, Dean W.; Polikarpov, Evgueni; Swensen, James S.; Bonham, Charles C.; Cosimbescu, Lelia; Berry, J. J.; Ginley, D. S.; Gaspar, Daniel J.; Padmaperuma, Asanga B.

2010-02-15T23:59:59.000Z

134

High Efficiency Steam Electrolyzer  

SciTech Connect

A novel steam electrolyzer has been developed. In conventional electrolyzers, oxygen produced from electrolysis is usually released in the air stream. In their novel design, natural gas is used to replace air in order to reduce the chemical potential difference across the electrolyzer, thus minimizing the electrical consumption. The oxygen from the electrolysis is consumed in either a total oxidation or a partial oxidation reaction with natural gas. Experiments performed on single cells shown a voltage reduction as much as 1 V when compared to conventional electrolyzers. Using thin film materials and high performance cathode and anode, electrolysis could be done at temperatures as low as 700 C with electrolytic current as high as 1 A/cm{sup 2} at a voltage of 0.5 V only. The 700 C operating temperature is favorable to the total oxidation of natural gas while minimizing the need for steam that is otherwise necessary to avoid carbon deposition. A novel tubular electrolyzer stack has been developed. The system was designed to produce hydrogen at high pressures, taking advantage of the simplicity and high efficiency of the electrochemical compressors. A complete fabrication process was developed for making electrolyzer tubes with thin film coatings. A 100 W stack is being built.

Pham, A.Q.

2000-06-19T23:59:59.000Z

135

Low Cost High Efficiency InP-Based Solar Cells: Cooperative Research and Development Final Report, CRADA Number CRD-09-344  

DOE Green Energy (OSTI)

NREL will develop a method of growing and fabricating single junction InP solar cells on 2-inch InP substrates on which a release layer has been deposited by MicroLink Devices. NREL will transfer to MicroLink the details of the InP solar cell layer structure and test results in order that the 2-inch results can be replicated on 4-inch InP substrates. NREL will develop a method of growing and fabricating single junction InP solar cells, including a metamorphic layer, on 2-inch GaAs substrates on which a release layer has been deposited by MicroLink Devices. NREL will transfer to MicroLink the details of the InP solar cell layer structure and test results in order that the 2-inch results can be replicated on 6-inch GaAs substrates. NREL will perform characterization measurements of the solar cells, including I-V and quantum efficiency measurements at AM1.5 1-sun.

Wanlass, M.

2012-07-01T23:59:59.000Z

136

Search for the Factors Determining the Photodegradation in High Efficiency a-Si:H Solar Cells: Final Subcontract Report, 28 January 1998 - 15 August 2001  

DOE Green Energy (OSTI)

This report describes continuing studies on photoluminescence (PL), electroluminescence (EL), Raman, and nuclear magnetic resonance (NMR) by the University of North Carolina-Chapel Hill during the three years and the extension period. Systematic studies on the transition materials and their solar cells and a review of the photo-induced structural changes in correlation to the electronic degradation have led to better understanding of the factors determining the photodegradation in a-Si:H solar cells. NHR established significant differences, as in the bonding of hydrogen in the hot-wire- and plasma-deposited amorphous silicon.

Han, D.

2002-03-01T23:59:59.000Z

137

High-Efficiency Amorphous Silicon and Nanocrystalline Silicon-Based Solar Cells and Modules: Final Technical Progress Report, 30 January 2006 - 29 January 2008  

DOE Green Energy (OSTI)

United Solar Ovonic successfully used its spectrum-splitting a-Si:H/a-SiGe:H/a-SiGe:H triple-junction structure in their manufacturing plants, achieving a manufacturing capacity of 118 MW in 2007, and set up a very aggressive expansion plan to achieve grid parity.

Guha, S.; Yang, J.

2008-05-01T23:59:59.000Z

138

Development of high-efficiency, thin-film CdTe solar cells. Final subcontract report, 1 February 1992--30 November 1995  

DOE Green Energy (OSTI)

This report describes work performed by the Georgia Institute of Technology (GIT) to bring the polycrystalline CdTe cell efficiency a step closer to the practically achievable efficiency of 18% through fundamental understanding of detects and loss mechanisms, the role of chemical and heat treatments, and investigation of now process techniques. The objective was addressed by a combination of in-depth characterization, modeling, materials growth, device fabrication, and `transport analyses of Au/Cu/CdTe/CdS/SnO {sub 2} glass front-wall heterojunction solar cells. GiT attempted to understand the loss mechanism(s) in each layer and interface by a step-by-step investigation of this multilayer cell structure. The first step was to understand, quantify, and reduce the reflectance and photocurrent loss in polycrystalline CdTe solar calls. The second step involved the investigation of detects and loss mechanisms associated with the CdTe layer and the CdTe/CdS interface. The third stop was to investigate the effect of chemical and heat treatments on CdTe films and cells. The fourth step was to achieve a better and reliable contact to CdTe solar cells by improving the fundamental understanding. Of the effects of Cu on cell efficiency. Finally, the research involved the investigation of the effect of crystallinity and grain boundaries on Cu incorporation in the CdTe films, including the fabrication of CdTe solar calls with larger CdTe grain size.

Rohatgi, A.; Chou, H.C.; Kamra, S.; Bhat, A. [Georgia Inst. of Tech., Atlanta, GA (United States)

1996-01-01T23:59:59.000Z

139

Fabrication and Characterization of Organic Solar Cells  

E-Print Network (OSTI)

8? Würfel P.  Physics of solar cells : from principles to Photocell for Converting  Solar Radiation into Electrical generation  photovoltaics:  solar  cells  for  2020  and 

Yengel, Emre

2010-01-01T23:59:59.000Z

140

Development of high-efficiency, thin-film CdTe solar cells. Annual subcontract report, January 1, 1993--December 31, 1993  

DOE Green Energy (OSTI)

Polycrystalline thin film CdTe solar cells are one of the leading candidates for terrestrial photovoltaic applications. Theoretical calculations project an efficiency of 27% for single crystal, single junction CdTe cells, and the practically achievable efficiency for polycrystalline CdTe cells is 18-20%. Polycrystalline CdTe cells made by different groups show a significant variation in short circuit currents, open circuit voltages, and cell efficiencies. A better understanding of carrier loss and transport mechanism is crucial for explaining these differences, improving the yield, and bridging the gap between current and practically achievable limits in CdTe cell efficiencies. The goal of this program is to improve the understanding of the loss mechanisms in thin film CdS/CdTe solar cells and to improve their efficiency by characterizing the properties of the films as well as the finished devices.

Rohatgi, A.; Chou, H.C.; Kamra, S.; Bhat, A. [Georgia Institute of Technology, Atlanta, GA (United States)

1994-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "high-efficiency organic solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Low-cost, high-efficiency solar cells utilizing GaAs-on-Si technology. Annual subcontract report, 1 August 1991--31 July 1992  

DOE Green Energy (OSTI)

This report describes work to develop technology to deposit GaAs on Si using a nucleation layer of atomic-layer-epitaxy-grown GaAs or AlAs on Si. This ensures two-dimensional nucleation and should lead to fewer defects in the final GaAs layer. As an alternative, we also developed technology for depositing GaAs on sawtooth-patterned Si. Preliminary studies showed that this material can have a very low defect density, {approximately} 1 {times} 10{sup 5} cm{sup {minus}5}, as opposed to our conventionally grown GaAs on SL which has a typical defect density of over 1 {times}10{sup 7} cm{sup {minus}2}. Using these two now methods of GaAs-on-Si material growth, we made solar cells that are expected to show higher efficiencies than those of previous cells.

Vernon, S.M. [Spire Corp., Bedford, MA (United States)

1993-04-01T23:59:59.000Z

142

Durable and Highly Efficient Energy-harvesting Electrochromic ...  

Science Conference Proceedings (OSTI)

The resulting device performed three states: solar cell, transparent, and dark, and ... Anatase Nanostructures for High Efficiency Photocatalysis Application ... EBSD Study of Electromigration Damage in Idealized SnAgCu 305 Interconnects.

143

The challenges of organic polymer solar cells  

E-Print Network (OSTI)

The technical and commercial prospects of polymer solar cells were evaluated. Polymer solar cells are an attractive approach to fabricate and deploy roll-to-roll processed solar cells that are reasonably efficient (total ...

Saif Addin, Burhan K. (Burhan Khalid)

2011-01-01T23:59:59.000Z

144

Fabrication and Characterization of Organic Solar Cells  

E-Print Network (OSTI)

5  Figure 1-3 The Solar Spectrum at the Top of thesolar cells. Figure 1-3 The Solar Spectrum at the Top of thenarrow range of solar spectrum, as they are commonly known

Yengel, Emre

2010-01-01T23:59:59.000Z

145

Controlled Structure of Organic-Nanomaterial Solar Cells  

By controlling the molecular shape, structure, and pattern of the materials in organic, polymer-based solar cells, Alex Zettl and Jeffrey Grossman of Berkeley Lab ...

146

NIST Measurements May Help Optimize Organic Solar Cells  

Science Conference Proceedings (OSTI)

... Organic solar cells may be a step closer to market because of measurements taken at the National Institute of Standards and Technology (NIST ...

2012-03-06T23:59:59.000Z

147

New Morphological Paradigm Uncovered in Organic Solar Cells  

NLE Websites -- All DOE Office Websites (Extended Search)

and environmentally friendly energy source. Understanding the fundamentals of organic solar cell function is therefore vital to uncovering their maximum potential. Models...

148

Advanced processing technology for high-efficiency thin-film CuInSe{sub 2} solar cells. Annual subcontract report, 1 March 1992--28 February 1993  

DOE Green Energy (OSTI)

This report describes work to develop novel fabrication for CuInSe{sub 2} (CIS) solar cells that will result in improved performance and cost effectiveness at the manufacturing level. The primary approach involves all solid-state processing for CIS. This was augmented by work to provide novel alternatives for the formation of the window layer/heterojunction contact. Inherent to the project was the need to develop a generic understanding of the relationship between processing and performance so that broad-based transfer to industry can be facilitated. We achieved good-electronic-quality CIS by the use of two selenization procedures for predeposited metal layers. We achieved good stoichiometry throughout the bulk of the film, attained grain sizes of up to 1 {mu}m, and measured electron mobilities of up to 60 cm{sup 2}V-s. However, there is a complex relationship between grain size, adhesion, and performance. Our primary approach to characterization was to fabricate ZnO/CIS test devices and measure as many properties as possible in device format. We are also developing reactive sputtering of ZnO as an alternative window layer technology.

Morel, D.L.; Attar, G.; Karthikeyan, S.; Muthaiah, A.; Zafar, A. [University of South Florida, Tampa, FL (United States)

1993-08-01T23:59:59.000Z

149

Search for Factors Determining the Photodegradation in High-Efficiency a-Si:H-Based Solar Cells; Annual Technical Progress Report, 16 January 1998-15 January 1999  

DOE Green Energy (OSTI)

This report describes studies on glow discharge (GD) and hot-wire a-Si-based samples by the University of North Carolina-Chapel Hill during Phase I. We have characterized H-bonding and its light-induced changes by using infrared (IR) and differential IR (DIR). For the less stable film, there is a simultaneous decrease {approx} 2040 cm{sup -1} and increase {approx} 1880 cm{sup -1}; for the more-stable samples, the DIR near 2000 cm{sup -1} increases upon light-soaking. Nuclear magnetic resonance (NMR) dipolar relaxation time T{sub 1D} of the clustered H is slightly shorter, but the T{sub 1D} of the isolated H is 4 times longer in hot-wire (HW) film than that in GD films. The results indicate that the local motion of the isolated H is much slower in HW compared to that in GD film. High-Temperature NMR results show a second narrow line (less than 1 kHz wide) as the temperature is raised. In stress measurements, it is clearly shown that HW films with lower hydrogen content show lower compression. A photoinduced increase of the compression on the order of 10{sup -4} of the initial value upon light-soaking was found to be similar in all a-Si:H films which exhibit different amounts of Staebler-Wronski (SW) degradation. Hence, the volume expansion is not directly related to SW effect. Also, we have measured the electric field profile in a-Si:H and a-SiGe:H solar cells, and the results agreed with computer simulation.

Han, D.

1999-06-18T23:59:59.000Z

150

High Efficiency Particulate Air Filters  

NLE Websites -- All DOE Office Websites (Extended Search)

High Efficiency Particulate Air (HEPA) Filters High Efficiency Particulate Air (HEPA) Filters Home Standards DOE Workshops Nuclear Air Cleaning Conference Proceedings Qualified Filter List News Items Related Sites HEPA Related Lessons Learned Contact Us HSS Logo High Efficiency Particulate Air Filters The HEPA Filter web site provides a forum for informing and reporting department-wide activities related to filtration and ventilation issues with special reference to the High Efficiency Particulate Air (HEPA) Filters' use, inspection, and testing. This site contains essentials of DOE HEPA filter test program, procedures, requirements and quality assurance aspects applicable to HEPA filters used in DOE facilities. This site contains information about the DOE-accepted Filter Test Facility and its management, operation and quality assuranceprogram.

151

High-efficiency silicon concentrator cell commercialization  

SciTech Connect

This report summarizes the first phase of a forty-one month program to develop a commercial, high-efficiency concentrator solar cell and facility for manufacturing it. The period covered is November 1, 1990 to December 31, 1991. This is a joint program between the Electric Power Research Institute (EPRI) and Sandia National Laboratories. (This report is also published by EPRI as EPRI report number TR-102035.) During the first year of the program, SunPower accomplished the following major objectives: (1) a new solar cell fabrication facility, which is called the Cell Pilot Line (CPL), (2) a baseline concentrator cell process has been developed, and (3) a cell testing facility has been completed. Initial cell efficiencies are about 23% for the baseline process. The long-range goal is to improve this efficiency to 27%.

Sinton, R.A.; Swanson, R.M. [SunPower Corp., Sunnyvale, CA (US)

1993-05-01T23:59:59.000Z

152

Process Technology and Advanced Concepts: Organic Solar Cells (Fact Sheet)  

DOE Green Energy (OSTI)

Capabilities fact sheet for the National Center for Photovoltaics: Process Technology and Advanced Concepts: Organic Solar Cell that includes scope, core competencies and capabilities, and contact/web information.

Not Available

2011-06-01T23:59:59.000Z

153

A model to determine financial indicators for organic solar cells  

Science Conference Proceedings (OSTI)

Organic solar cells are an emerging photovoltaic technology that is inexpensive and easy to manufacture, despite low efficiency and stability. A model, named TEEOS (Technical and Economic Evaluator for Organic Solar), is presented that evaluates organic solar cells for various solar energy applications in different geographic locations, in terms of two financial indicators, payback period and net present value (NPV). TEEOS uses SMARTS2 software to estimate broadband (280-4000 nm) spectral irradiance data and with the use of a cloud modification factor, predicts hourly irradiation in the absence of actual broadband irradiance data, which is scarce for most urban locations. By using the avoided cost of electricity, annual savings are calculated which produce the financial indicators. It is hoped that these financial indicators can help guide certain technical decisions regarding the direction of research for organic solar cells, for example, increasing efficiency or increasing the absorptive wavelength range. A sample calculation using solar hats is shown to be uneconomical, but a good example of large-scale organic PV production. (author)

Powell, Colin; Bender, Timothy; Lawryshyn, Yuri [Department of Chemical Engineering and Applied Chemistry, Faculty of Engineering and Applied Science, University of Toronto, 200 College Street, Toronto, Ont. (Canada)

2009-11-15T23:59:59.000Z

154

Evaluating High Efficiency Motor Retrofit  

E-Print Network (OSTI)

In the petrochemical and refining Industries, and most manufacturing plants, the reliable operation of AC motors always has been crucial to the continuous operation of the process. Now, the cost of operating these motors has also become a significant factor. Engineers Involved In motor specification can help lower plant operating costs and reduce electrical energy consumption dramatically by a relatively simple technique: retrofit of existing, standard-efficiency motors with new, high efficiency models. This article demonstrates strong reasons for motor retrofit, and explains step-by step how process and manufacturing engineering personnel can fully evaluate a retrofit decision.

Evans, T. A.

1984-01-01T23:59:59.000Z

155

High-efficiency photoionization detector  

DOE Patents (OSTI)

A high efficiency photoionization detector using tetraaminoethylenes in a gaseous state having a low ionization potential and a relative photoionization cross section which closely matches the emission spectrum of xenon gas. Imaging proportional counters are also disclosed using the novel photoionization detector of the invention. The compound of greatest interest is TMAE which comprises tetrakis(dimethylamino)ethylene which has a measured ionization potential of 5.36 +- 0.02 eV, and a vapor pressure of 0.35 torr at 20/sup 0/C.

Anderson, D.F.

1981-05-12T23:59:59.000Z

156

SunShot Initiative: High-Efficiency Thermal Storage System for...  

NLE Websites -- All DOE Office Websites (Extended Search)

Efficiency Thermal Storage System for Solar Plants to someone by E-mail Share SunShot Initiative: High-Efficiency Thermal Storage System for Solar Plants on Facebook Tweet about...

157

Organic Solar Cells: Absolute Measurement of Domain Composition and  

NLE Websites -- All DOE Office Websites (Extended Search)

Organic Solar Cells: Absolute Organic Solar Cells: Absolute Measurement of Domain Composition and Nanoscale Size Distribution Explains Performance in Solar Cells Organic Solar Cells: Absolute Measurement of Domain Composition and Nanoscale Size Distribution Explains Performance in Solar Cells Print Tuesday, 22 January 2013 00:00 This front cover represents the morphology and resulting device dynamics in organic solar cell blend films of PTB7 and PC71BM, as revealed by combined resonant x-ray scattering and microscopy done at the Advanced Light Source. Harald Ade and co-workers find that the fullerene molecules (red) are miscible in the polymer (blue) up to 30 wt.%, above which they begin to agglomerate (bottom). This agglomeration is important for the optoelectronic processes within the device, but the agglomerates must be kept to small sizes by the solvent processing additive diiodooctane (DIO). Correlation of this morphology with the spectrally resolved quantum efficiency shows that the yellow excitons created upon photoabsorption must arrive at the agglomerate interface for charge separation to occur. The blue electrons and green holes can then percolate through appropriate molecules in the mixed matrix to the electrodes for harvesting of electrical energy. Article Link (PDF)

158

New Morphological Paradigm Uncovered in Organic Solar Cells  

NLE Websites -- All DOE Office Websites (Extended Search)

New Morphological Paradigm Uncovered in Organic Solar Cells Print New Morphological Paradigm Uncovered in Organic Solar Cells Print Organic solar cells are made of light, flexible, renewable materials; they require simple and inexpensive processing steps and could produce an economically competitive and environmentally friendly energy source. Understanding the fundamentals of organic solar cell function is therefore vital to uncovering their maximum potential. Models describing critical device functions such as charge separation and transport often depend on simplistic morphological assumptions, including discrete interfaces between pure electron donor and acceptor materials. In contrast, recent spectroscopy and scattering studies conducted by North Carolina State University and Cambridge University researchers at ALS Beamlines 5.3.2 and 7.3.3 found a substantial amount of molecular mixing between model materials (polymers and fullerenes) currently used in bulk heterojunction (BHJ) organic solar cells. This suggests that the amorphous portions of these devices do not have pure domains, and the paradigm of device operation may need to be refined to accommodate this newly discovered complexity.

159

New Morphological Paradigm Uncovered in Organic Solar Cells  

NLE Websites -- All DOE Office Websites (Extended Search)

New Morphological Paradigm Uncovered in Organic Solar Cells Print New Morphological Paradigm Uncovered in Organic Solar Cells Print Organic solar cells are made of light, flexible, renewable materials; they require simple and inexpensive processing steps and could produce an economically competitive and environmentally friendly energy source. Understanding the fundamentals of organic solar cell function is therefore vital to uncovering their maximum potential. Models describing critical device functions such as charge separation and transport often depend on simplistic morphological assumptions, including discrete interfaces between pure electron donor and acceptor materials. In contrast, recent spectroscopy and scattering studies conducted by North Carolina State University and Cambridge University researchers at ALS Beamlines 5.3.2 and 7.3.3 found a substantial amount of molecular mixing between model materials (polymers and fullerenes) currently used in bulk heterojunction (BHJ) organic solar cells. This suggests that the amorphous portions of these devices do not have pure domains, and the paradigm of device operation may need to be refined to accommodate this newly discovered complexity.

160

New Morphological Paradigm Uncovered in Organic Solar Cells  

NLE Websites -- All DOE Office Websites (Extended Search)

New Morphological Paradigm Uncovered in Organic Solar Cells Print New Morphological Paradigm Uncovered in Organic Solar Cells Print Organic solar cells are made of light, flexible, renewable materials; they require simple and inexpensive processing steps and could produce an economically competitive and environmentally friendly energy source. Understanding the fundamentals of organic solar cell function is therefore vital to uncovering their maximum potential. Models describing critical device functions such as charge separation and transport often depend on simplistic morphological assumptions, including discrete interfaces between pure electron donor and acceptor materials. In contrast, recent spectroscopy and scattering studies conducted by North Carolina State University and Cambridge University researchers at ALS Beamlines 5.3.2 and 7.3.3 found a substantial amount of molecular mixing between model materials (polymers and fullerenes) currently used in bulk heterojunction (BHJ) organic solar cells. This suggests that the amorphous portions of these devices do not have pure domains, and the paradigm of device operation may need to be refined to accommodate this newly discovered complexity.

Note: This page contains sample records for the topic "high-efficiency organic solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

New Morphological Paradigm Uncovered in Organic Solar Cells  

NLE Websites -- All DOE Office Websites (Extended Search)

New Morphological Paradigm New Morphological Paradigm Uncovered in Organic Solar Cells New Morphological Paradigm Uncovered in Organic Solar Cells Print Wednesday, 27 April 2011 00:00 Organic solar cells are made of light, flexible, renewable materials; they require simple and inexpensive processing steps and could produce an economically competitive and environmentally friendly energy source. Understanding the fundamentals of organic solar cell function is therefore vital to uncovering their maximum potential. Models describing critical device functions such as charge separation and transport often depend on simplistic morphological assumptions, including discrete interfaces between pure electron donor and acceptor materials. In contrast, recent spectroscopy and scattering studies conducted by North Carolina State University and Cambridge University researchers at ALS Beamlines 5.3.2 and 7.3.3 found a substantial amount of molecular mixing between model materials (polymers and fullerenes) currently used in bulk heterojunction (BHJ) organic solar cells. This suggests that the amorphous portions of these devices do not have pure domains, and the paradigm of device operation may need to be refined to accommodate this newly discovered complexity.

162

Fabrication and Characterization of Organic Solar Cells  

E-Print Network (OSTI)

processable polymer photovoltaic cells by self?organization Photodiodes,  and  Photovoltaic  Cells.   Applied Physics F,  Heeger  AJ.   Polymer  Photovoltaic  Cells  ?  Enhanced 

Yengel, Emre

2010-01-01T23:59:59.000Z

163

Fabrication and Characterization of Organic Solar Cells  

E-Print Network (OSTI)

be a good candidate to the energy problem. There are obvioussolution to the upcoming energy problem because of theirstructures to this energy harvesting problem using organic

Yengel, Emre

2010-01-01T23:59:59.000Z

164

High Efficiency Engine Technologies Program  

Science Conference Proceedings (OSTI)

Caterpillar's Product Development and Global Technology Division carried out a research program on waste heat recovery with support from DOE (Department of Energy) and the DOE National Energy Technology Laboratory. The objective of the program was to develop a new air management and exhaust energy recovery system that would demonstrate a minimum 10% improvement in thermal efficiency over a base heavy-duty on-highway diesel truck engine. The base engine for this program was a 2007 C15 15.2L series-turbocharged on-highway truck engine with a LPL (low-pressure loop) exhaust recirculation system. The focus of the program was on the development of high efficiency turbomachinery and a high efficiency turbocompound waste heat recovery system. The focus of each area of development was as follows: (1) For turbine stages, the focus was on investigation and development of technologies that would improve on-engine exhaust energy utilization compared to the conventional radial turbines in widespread use today. (2) For compressor stages, the focus was on investigating compressor wheel design parameters beyond the range typically utilized in production, to determine the potential efficiency benefits thereof. (3) For turbocompound, the focus was on the development of a robust bearing system that would provide higher bearing efficiencies compared to systems used in turbocompound power turbines in production. None of the turbocharger technologies investigated involved addition of moving parts, actuators, or exotic materials, thereby increasing the likelihood of a favorable cost-value tradeoff for each technology. And the turbocompound system requires less hardware addition than competing bottoming cycle technologies, making it a more attractive solution from a cost and packaging standpoint. Main outcomes of the program are as follows: (1) Two turbine technologies that demonstrated up to 6% improvement in turbine efficiency on gas stand and 1-3% improvement in thermal efficiency in on-engine testing. (2) A compressor technology that demonstrated 1.5% improvement in compressor efficiency on gas stand compared to production available compressors. (3) A power turbine with high efficiency bearing system that demonstrated excellent rotordynamic stability throughout the required speed range, up to 60,000 rpm. (4) A predicted improvement (using engine simulation) in engine thermal efficiency of 7% at the peak torque design point, when combining the technologies developed in this program.

Rich Kruiswyk

2010-07-13T23:59:59.000Z

165

High-Efficiency Steam Electrolyzer  

SciTech Connect

We are developing a novel high-efficiency, high-temperature steam electrolyzer. Although water or steam electrolysis is well known to be one of the cleanest ways to produce hydrogen, widespread utilization is hindered by high operational costs because of high electricity consumption. To decrease the electrical power input requirements in electrolysis, our approach uses natural gas as an anode depolarizer. This approach essentially replaces one unit of electricity with one equivalent-energy unit of natural gas at much lower cost. The direct use of natural gas on the electrolyzer enables very high system efficiency with respect to primary energy. Experiments performed on single cells have shown a voltage reduction as much as 1 V when compared to conventional electrolyzers. System efficiency has been estimated to be 50 to 80%, depending on the electrolytic current. A 200-W prototype unit is being developed.

Pham, A Q

2001-06-20T23:59:59.000Z

166

Preparation of cuxinygazsen (X=0-2, Y=0-2, Z=0-2, N=0-3) precursor films by electrodeposition for fabricating high efficiency solar cells  

DOE Patents (OSTI)

High quality thin films of copper-indium-gallium-diselenide useful in the production of solar cells are prepared by electrodepositing at least one of the constituent metals onto a glass/Mo substrate, followed by physical vapor deposition of copper and selenium or indium and selenium to adjust the final stoichiometry of the thin film to approximately Cu(In,Ga)Se.sub.2. Using an AC voltage of 1-100 KHz in combination with a DC voltage for electrodeposition improves the morphology and growth rate of the deposited thin film. An electrodeposition solution comprising at least in part an organic solvent may be used in conjunction with an increased cathodic potential to increase the gallium content of the electrodeposited thin film.

Bhattacharya, Raghu N. (Littleton, CO); Contreras, Miguel A. (Golden, CO); Keane, James (Lakewood, CO); Tennant, Andrew L. (Denver, CO); Tuttle, John R. (Denver, CO); Ramanathan, Kannan (Lakewood, CO); Noufi, Rommel (Golden, CO)

1998-03-24T23:59:59.000Z

167

SunShot Initiative: High-Efficiency Thermal Energy Storage System for CSP  

NLE Websites -- All DOE Office Websites (Extended Search)

High-Efficiency Thermal Energy High-Efficiency Thermal Energy Storage System for CSP to someone by E-mail Share SunShot Initiative: High-Efficiency Thermal Energy Storage System for CSP on Facebook Tweet about SunShot Initiative: High-Efficiency Thermal Energy Storage System for CSP on Twitter Bookmark SunShot Initiative: High-Efficiency Thermal Energy Storage System for CSP on Google Bookmark SunShot Initiative: High-Efficiency Thermal Energy Storage System for CSP on Delicious Rank SunShot Initiative: High-Efficiency Thermal Energy Storage System for CSP on Digg Find More places to share SunShot Initiative: High-Efficiency Thermal Energy Storage System for CSP on AddThis.com... Concentrating Solar Power Systems Components Competitive Awards CSP Research & Development Thermal Storage CSP Recovery Act

168

High-Efficiency Steam Electrolyzer  

SciTech Connect

We are developing a novel high-efficiency, high-temperature steam electrolyzer. Although water or steam electrolysis is well known to be one of the cleanest ways to produce hydrogen, widespread utilization is hindered by high operational costs because of high electricity consumption. To decrease the electrical power input requirements in electrolysis, our approach uses natural gas as an anode depolarizer. This approach essentially replaces one unit of electricity with one equivalent-energy unit of natural gas at much lower cost. The direct use of natural gas on the electrolyzer enables very high system efficiency with respect to primary energy. Experiments performed on single cells have shown a voltage reduction as much as 1 V when compared to conventional electrolyzers. System efficiency has been estimated to be 50 to 80%, depending on the electrolytic current density. During FY02, we have accomplished several major milestones, including the development of a metal-to-ceramic seal that withstands 150 psi differential, the fabrication of the electrolyzer tubes of up to 16 inches in length, the improvement of single tube performance and the demonstration of the first electrolyzer stack.

Pham, A Q; See, E; Lenz, D; Martin, P; Glass, R

2002-07-03T23:59:59.000Z

169

Advanced processing technology for high-efficiency, thin-film CuInSe{sub 2} and CdTe solar cells. Annual subcontract report, 1 March 1993--28 February 1994  

Science Conference Proceedings (OSTI)

This annual report details activities in research on advanced processing technology for high-effiency, thin-film solar cells.

Morel, D.L.; Ferekides, C.S. [University of South Florida, Tampa, FL (United States)

1994-07-01T23:59:59.000Z

170

High efficiency shale oil recovery  

SciTech Connect

The overall project objective is to demonstrate the high efficiency of the Adams Counter-Current shale oil recovery process. The efficiency will first be demonstrated on a small scale, in the current phase, after which the demonstration will be extended to the operation of a small pilot plant. Thus the immediate project objective is to obtain data on oil shale retorting operations in a small batch rotary kiln that will be representative of operations in the proposed continuous process pilot plant. Although an oil shale batch sample is sealed in the batch kiln from the start until the end of the run, the process conditions for the batch are the same as the conditions that an element of oil shale would encounter in a continuous process kiln. Similar chemical and physical conditions (heating, mixing, pyrolysis, oxidation) exist in both systems.The two most important data objectives in this phase of the project are to demonstrate (1) that the heat recovery projected for this project is reasonable and (2) that an oil shale kiln will run well and not plug up due to sticking and agglomeration. The following was completed this quarter. (1) Twelve pyrolysis runs were made on five different oil shales. All of the runs exhibited a complete absence of any plugging, tendency. Heat transfer for Green River oil shale in the rotary kiln was 84.6 Btu/hr/ft[sup 2]/[degrees]F, and this will provide for ample heat exchange in the Adams kiln. (2) One retorted residue sample was oxidized at 1000[degrees]F. Preliminary indications are that the ash of this run appears to have been completely oxidized. (3) Further minor equipment repairs and improvements were required during the course of the several runs.

Adams, D.C.

1993-04-22T23:59:59.000Z

171

High efficiency shale oil recovery  

SciTech Connect

The overall project objective is to demonstrate the high efficiency of the Adams Counter-Current shale oil recovery process. The efficiency will first be demonstrated at bench-scale, in the current phase, after which the demonstration will be extended to the operation of a small pilot plant. Thus the immediate project objective is to obtain data on oil shale retorting operations in a small batch rotary kiln that will be representative of operations in the proposed continuous process pilot plant. Although a batch oil shale sample will be sealed in the batch kiln from the start until the end of the run, the process conditions for the batch will be the same as the conditions that an element of oil shale would encounter in a large continuous process kiln. For example, similar conditions of heat-up rate (20 deg F/min during the pyrolysis), oxidation of the residue and cool-down will prevail for the element in both systems. This batch kiln is a unit constructed in a 1987 Phase I SBIR tar sand retorting project. The kiln worked fairly well in that project; however, the need for certain modifications was observed. These modifications are now underway to simplify the operation and make the data and analysis more exact. The agenda for the first three months of the project consisted of the first of nine tasks and was specified as the following four items: 1. Sample acquisition and equipment alteration: Obtain seven oil shale samples, of varying grade each 10 lb or more, and samples of quartz sand. Order equipment for kiln modification. 3. Set up and modify kiln for operation, including electric heaters on the ends of the kiln. 4. Connect data logger and make other repairs and changes in rotary batch kiln.

Adams, D.C.

1992-01-01T23:59:59.000Z

172

High efficiency shale oil recovery  

SciTech Connect

The overall project objective is to demonstrate the high efficiency of the Adams Counter-Current shale oil recovery process. The efficiency will first be demonstrated on a small scale, in the current phase, after which the demonstration will be extended to the operation of a small pilot plant. Thus the immediate project objective is to obtain data on oil shale retorting operations in a small batch rotary kiln that will be representative of operations in the proposed continuous process pilot plant. Although an oil shale batch sample is sealed in the batch kiln from the start until the end of the run, the process conditions for the batch are the same as the conditions that an element of oil shale would encounter in a continuous process kiln. Similar chemical and physical (heating, mixing) conditions exist in both systems. The two most important data objectives in this phase of the project are to demonstrate (1) that the heat recovery projected for this project is reasonable and (2) that an oil shale kiln will run well and not plug up due to sticking and agglomeration. The following was completed and is reported on this quarter: (1) A software routine was written to eliminate intermittently inaccurate temperature readings. (2) We completed the quartz sand calibration runs, resolving calibration questions from the 3rd quarter. (3) We also made low temperature retorting runs to identify the need for certain kiln modifications and kiln modifications were completed. (4) Heat Conductance data on two Pyrolysis runs were completed on two samples of Occidental oil shale.

Adams, D.C.

1992-01-01T23:59:59.000Z

173

Solar Junction | Open Energy Information  

Open Energy Info (EERE)

Junction Jump to: navigation, search Name Solar Junction Place San Jose, California Zip CA 95131 Sector Efficiency, Solar Product Solar Junction is developing high efficiency solar...

174

Scientists at ALS Find New Path to More Efficient Organic Solar...  

NLE Websites -- All DOE Office Websites (Extended Search)

Scientists at ALS Find New Path to More Efficient Organic Solar Cells Scientists at ALS Find New Path to More Efficient Organic Solar Cells Print Monday, 07 January 2013 00:00...

175

NIST Scientists Study How to Stack the Deck for Organic Solar ...  

Science Conference Proceedings (OSTI)

NIST Scientists Study How to Stack the Deck for Organic Solar Power. For Immediate Release: July 28, 2009. ...

2012-10-02T23:59:59.000Z

176

Demo: Organic Solar Cell-equipped Energy Harvesting Active Networked Tag (EnHANT) Prototypes  

E-Print Network (OSTI)

Demo: Organic Solar Cell-equipped Energy Harvesting Active Networked Tag (EnHANT) Prototypes Gerald their communications and networking parameters to the available environmental energy harvested by the organic solar harvesting, organic solar cells, ultra-low-power com- munications, ultra-wideband impulse radio, energy

Carloni, Luca

177

Highly Efficient Modeling of Dynamic Coronal Loops  

E-Print Network (OSTI)

Observational and theoretical evidence suggests that coronal heating is impulsive and occurs on very small cross-field spatial scales. A single coronal loop could contain a hundred or more individual strands that are heated quasi-independently by nanoflares. It is therefore an enormous undertaking to model an entire active region or the global corona. Three-dimensional MHD codes have inadequate spatial resolution, and 1D hydro codes are too slow to simulate the many thousands of elemental strands that must be treated in a reasonable representation. Fortunately, thermal conduction and flows tend to smooth out plasma gradients along the magnetic field, so "0D models" are an acceptable alternative. We have developed a highly efficient model called Enthalpy-Based Thermal Evolution of Loops (EBTEL) that accurately describes the evolution of the average temperature, pressure, and density along a coronal strand. It improves significantly upon earlier models of this type--in accuracy, flexibility, and capability. It treats both slowly varying and highly impulsive coronal heating; it provides the differential emission measure distribution, DEM(T), at the transition region footpoints; and there are options for heat flux saturation and nonthermal electron beam heating. EBTEL gives excellent agreement with far more sophisticated 1D hydro simulations despite using four orders of magnitude less computing time. It promises to be a powerful new tool for solar and stellar studies.

J. A. Klimchuk; S. Patsourakos; P. J. Cargill

2007-10-01T23:59:59.000Z

178

Unraveling the Role of Morphology on Organic Solar Cell Performance  

E-Print Network (OSTI)

Polymer based organic photovoltaic (OPV) technology offers a relatively inexpensive option for solar energy conversion provided its efficiency increases beyond the current level (6-7%) along with significant improvements in operational lifetime. The critical aspect of such solar cells is the complex morphology of distributed bulk heterojunctions, which plays the central role in the conversion of photo-generated excitons to electron-hole pairs. However, the fabrication conditions that can produce the optimal morphology are still unknown due to the lack of quantitative understanding of the effects of process variables on the cell morphology. In this article, we develop a unique process-device co-simulation framework based on phase-field model for phase separation coupled with self-consistent drift-diffusion transport to quantitatively explore the effects of the process conditions (e.g., annealing temperature, mixing ratio, anneal duration) on the organic solar cell performance. Our results explain experimentally observed trends of open circuit voltage and short circuit current that would otherwise be deemed anomalous from the perspective of conventional solar cells. In addition to providing an optimization framework for OPV technology, our morphology-aware modeling approach is ideally suited for a wide class of problems involving porous materials, block co-polymers, polymer colloids, OLED devices etc.

Biswajit Ray; Pradeep R. Nair; Muhammad A. Alam

2010-11-03T23:59:59.000Z

179

Testing of the Sunstove Organization's Sunstove Solar Oven  

E-Print Network (OSTI)

A Sunstove Organization's Sunstove was tested at Sandia's Solar Thermal Test Facility. It was instrumented with five type K thermocouples to determine warm-up rates when empty and when a pot containing two liters of water was placed inside. It reached inside air temperatures above 115 o C (240 o F). It heated two liters of water from room temperature to 80 o C (175 o F) in about two hours. Observations were made on the cooling and reheating rates during a cloud passage. The adverse effects of wind on the operation of the solar oven were also noted. ii 1 The Solar Thermal Design Assistance Center (STDAC) at Sandia National Laboratories evaluated a Sunstove from the Sunstove Organization, at Sandia's Solar Thermal Test Facility in Albuquerque NM. It was designed for single family household cooking. It is targeting developing countries' alternative energy markets where conventional fuels are not available and wood is the primary fuel used for cooking. Because of the wide vari...

Moss Solar Thermal; T. A. Moss

1997-01-01T23:59:59.000Z

180

High-Efficiency Neutron Detection and Spectroscopy ...  

Science Conference Proceedings (OSTI)

... are also working on a large volume detector to use in the underground environment where high efficiency is more important that energy resolution. ...

2013-07-22T23:59:59.000Z

Note: This page contains sample records for the topic "high-efficiency organic solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Basic studies of 3-5 high efficiency cell components  

DOE Green Energy (OSTI)

This project's objective is to improve our understanding of the generation, recombination, and transport of carriers within III-V homo- and heterostructures. The research itself consists of fabricating and characterizing solar cell building blocks'' such as junctions and heterojunctions as well as basic measurements of material parameters. A significant effort is also being directed at characterizing loss mechanisms in high-quality, III-V solar cells fabricated in industrial research laboratories throughout the United States. The project's goal is to use our understanding of the device physics of high-efficiency cell components to maximize cell efficiency. A related goal is the demonstration of new cell structures fabricated by molecular beam epitaxy (MBE). The development of measurement techniques and characterization methodologies is also a project objective. This report describes our progress during the fifth and final year of the project. During the past five years, we've teamed a great deal about heavy doping effects in p[sup +] and n[sup +] GaAs and have explored their implications for solar cells. We have developed an understanding of the dominant recombination losses in present-day, high-efficiency cells. We've learned to appreciated the importance of recombination at the perimeter of the cell and have developed techniques for chemically passivating such edges. Finally, we've demonstrated that films grown by molecular beam epitaxy are suitable for high-efficiency cell research.

Lundstrom, M.S.; Melloch, M.R.; Pierret, R.F.; Carpenter, M.S.; Chuang, H.L.; Dodd, P.E.; Keshavarzi, A.; Klausmeier-Brown, M.E.; Lush, G.B.; Stellwag, T.B. (Purdue Univ., Lafayette, IN (United States))

1993-01-01T23:59:59.000Z

182

SunShot Initiative: Development and Productization of High-Efficiency,  

NLE Websites -- All DOE Office Websites (Extended Search)

Development and Productization of Development and Productization of High-Efficiency, Low-Cost Building-Integrated PV Shingles Using Monocrystalline Silicon Thin-Film Solar Cells to someone by E-mail Share SunShot Initiative: Development and Productization of High-Efficiency, Low-Cost Building-Integrated PV Shingles Using Monocrystalline Silicon Thin-Film Solar Cells on Facebook Tweet about SunShot Initiative: Development and Productization of High-Efficiency, Low-Cost Building-Integrated PV Shingles Using Monocrystalline Silicon Thin-Film Solar Cells on Twitter Bookmark SunShot Initiative: Development and Productization of High-Efficiency, Low-Cost Building-Integrated PV Shingles Using Monocrystalline Silicon Thin-Film Solar Cells on Google Bookmark SunShot Initiative: Development and Productization of

183

Enabling High Efficiency Ethanol Engines  

Science Conference Proceedings (OSTI)

Delphi Automotive Systems and ORNL established this CRADA to explore the potential to improve the energy efficiency of spark-ignited engines operating on ethanol-gasoline blends. By taking advantage of the fuel properties of ethanol, such as high compression ratio and high latent heat of vaporization, it is possible to increase efficiency with ethanol blends. Increasing the efficiency with ethanol-containing blends aims to remove a market barrier of reduced fuel economy with E85 fuel blends, which is currently about 30% lower than with petroleum-derived gasoline. The same or higher engine efficiency is achieved with E85, and the reduction in fuel economy is due to the lower energy density of E85. By making ethanol-blends more efficient, the fuel economy gap between gasoline and E85 can be reduced. In the partnership between Delphi and ORNL, each organization brought a unique and complementary set of skills to the project. Delphi has extensive knowledge and experience in powertrain components and subsystems as well as overcoming real-world implementation barriers. ORNL has extensive knowledge and expertise in non-traditional fuels and improving engine system efficiency for the next generation of internal combustion engines. Partnering to combine these knowledge bases was essential towards making progress to reducing the fuel economy gap between gasoline and E85. ORNL and Delphi maintained strong collaboration throughout the project. Meetings were held regularly, usually on a bi-weekly basis, with additional reports, presentations, and meetings as necessary to maintain progress. Delphi provided substantial hardware support to the project by providing components for the single-cylinder engine experiments, engineering support for hardware modifications, guidance for operational strategies on engine research, and hardware support by providing a flexible multi-cylinder engine to be used for optimizing engine efficiency with ethanol-containing fuels.

Szybist, J.; Confer, K. (Delphi Automotive Systems)

2011-03-01T23:59:59.000Z

184

Interfacial Engineering for Highly Efficient-Conjugated Polymer-Based Bulk Heterojunction Photovoltaic Devices  

Science Conference Proceedings (OSTI)

The aim of our proposal is to apply interface engineering approach to improve charge extraction, guide active layer morphology, improve materials compatibility, and ultimately allow the fabrication of high efficiency tandem cells. Specifically, we aim at developing: i. Interfacial engineering using small molecule self-assembled monolayers ii. Nanostructure engineering in OPVs using polymer brushes iii. Development of efficient light harvesting and high mobility materials for OPVs iv. Physical characterization of the nanostructured systems using electrostatic force microscopy, and conducting atomic force microscopy v. All-solution processed organic-based tandem cells using interfacial engineering to optimize the recombination layer currents vi. Theoretical modeling of charge transport in the active semiconducting layer The material development effort is guided by advanced computer modeling and surface/ interface engineering tools to allow us to obtain better understanding of the effect of electrode modifications on OPV performance for the investigation of more elaborate device structures. The materials and devices developed within this program represent a major conceptual advancement using an integrated approach combining rational molecular design, material, interface, process, and device engineering to achieve solar cells with high efficiency, stability, and the potential to be used for large-area roll-to-roll printing. This may create significant impact in lowering manufacturing cost of polymer solar cells for promoting clean renewable energy use and preventing the side effects from using fossil fuels to impact environment.

Alex Jen; David Ginger; Christine Luscombe; Hong Ma

2012-04-02T23:59:59.000Z

185

Productization and Manufacturing Scaling of High-Efficiency Solar Cell and Module Products Based on a Disruptive Low-Cost, Mono-Crystalline Technology: Final Technical Progress Report, April 1, 2009 - December 30, 2010  

DOE Green Energy (OSTI)

Final report for PV incubator subcontract with Solexel, Inc. The purpose of this project was to develop Solexel's Unique IP, productize it, and transfer it to manufacturing. Silicon constitutes a significant fraction of the total solar cell cost, resulting in an industry-wide drive to lower silicon usage. Solexel's disruptive Solar cell structure got around these challenges and promised superior light trapping, efficiency and mechanical strength, despite being significantly thinner than commercially available cells. Solexel's successful participation in this incubator project became evident as the company is now moving into commercial production and position itself to be competitive for the next Technology Pathway Partnerships (TPP) funding opportunity.

Fatemi, H.

2012-07-01T23:59:59.000Z

186

AEROSPACE TECHNOLOGY REVIEW FOR LBL WINDOW/PASSIVE SOLAR PROGRAM FINAL REPORT  

E-Print Network (OSTI)

F. Uno, "High Efficiency Solar Panel (HESP)! ', N78 10572,High Efficiency, Long Life Terrestrial Solar Panel", 7 8Ncapabilities, the efficiency of the solar panels, co-

Viswanathan, R.

2011-01-01T23:59:59.000Z

187

Effect of DC to DC converters on organic solar cell arrays for powering DC loads .  

E-Print Network (OSTI)

??The objective of this research is to determine if it is possible to reduce the number of organic solar cells required to power a load… (more)

Trotter, Matthew S.

2009-01-01T23:59:59.000Z

188

Energetic Barrier Prevents Recombination in Organic Solar Photoconversion Systems (Fact Sheet)  

DOE Green Energy (OSTI)

NREL researchers unravel the factors that affect charge generation and loss in high-performance conjugated polymer-fullerene blends used in organic solar cells.

Not Available

2012-08-01T23:59:59.000Z

189

Modifying the organic/electrode interface in Organic Solar Cells (OSCs) and improving the efficiency of solution-processed phosphorescent Organic Light-Emitting Diodes (OLEDs)  

SciTech Connect

Organic semiconductors devices, such as, organic solar cells (OSCs), organic light-emitting diodes (OLEDs) and organic field-effect transistors (OFETs) have drawn increasing interest in recent decades. As organic materials are flexible, light weight, and potentially low-cost, organic semiconductor devices are considered to be an alternative to their inorganic counterparts. This dissertation will focus mainly on OSCs and OLEDs. As a clean and renewable energy source, the development of OSCs is very promising. Cells with 9.2% power conversion efficiency (PCE) were reported this year, compared to < 8% two years ago. OSCs belong to the so-called third generation solar cells and are still under development. While OLEDs are a more mature and better studied field, with commercial products already launched in the market, there are still several key issues: (1) the cost of OSCs/OLEDs is still high, largely due to the costly manufacturing processes; (2) the efficiency of OSCs/OLEDs needs to be improved; (3) the lifetime of OSCs/OLEDs is not sufficient compared to their inorganic counterparts; (4) the physics models of the behavior of the devices are not satisfactory. All these limitations invoke the demand for new organic materials, improved device architectures, low-cost fabrication methods, and better understanding of device physics. For OSCs, we attempted to improve the PCE by modifying the interlayer between active layer/metal. We found that ethylene glycol (EG) treated poly(3,4-ethylenedioxythiophene): polystyrenesulfonate (PEDOT: PSS) improves hole collection at the metal/polymer interface, furthermore it also affects the growth of the poly(3- hexylthiophene) (P3HT):phenyl-C61-butyric acid methyl ester (PCBM) blends, making the phase segregation more favorable for charge collection. We then studied organic/inorganic tandem cells. We also investigated the effect of a thin LiF layer on the hole-collection of copper phthalocyanine (CuPc)/C70-based small molecular OSCs. A thin LiF layer serves typically as the electron injection layer in OLEDs and electron collection interlayer in the OSCs. However, several reports showed that it can also assist in holeinjection in OLEDs. Here we first demonstrate that it assists hole-collection in OSCs, which is more obvious after air-plasma treatment, and explore this intriguing dual role. For OLEDs, we focus on solution processing methods to fabricate highly efficient phosphorescent OLEDs. First, we investigated OLEDs with a polymer host matrix, and enhanced charge injection by adding hole- and electron-transport materials into the system. We also applied a hole-blocking and electron-transport material to prevent luminescence quenching by the cathode. Finally, we substituted the polymer host by a small molecule, to achieve more efficient solution processed small molecular OLEDs (SMOLEDs); this approach is cost-effective in comparison to the more common vacuum thermal evaporation. All these studies help us to better understand the underlying relationship between the organic semiconductor materials and the OSCs and OLEDs’ performance and will subsequently assist in further enhancing the efficiencies of OSCs and OLEDs. With better efficiency and longer lifetime, the OSCs and OLEDs will be competitive with their inorganic counterparts.

Xiao, Teng

2012-04-27T23:59:59.000Z

190

Measure Guideline: High Efficiency Natural Gas Furnaces  

SciTech Connect

This Measure Guideline covers installation of high-efficiency gas furnaces. Topics covered include when to install a high-efficiency gas furnace as a retrofit measure, how to identify and address risks, and the steps to be used in the selection and installation process. The guideline is written for Building America practitioners and HVAC contractors and installers. It includes a compilation of information provided by manufacturers, researchers, and the Department of Energy as well as recent research results from the Partnership for Advanced Residential Retrofit (PARR) Building America team.

Brand, L.; Rose, W.

2012-10-01T23:59:59.000Z

191

Microscopic Mechanism of the Staebler-Wronski Effect in a-Si Films and High-Efficiency Solar Cells: Final Subcontract Report, 1 October 2001--30 September 2004  

DOE Green Energy (OSTI)

In high growth rate ({ge} 50 {angstrom}/s) HW-CVD a-Si:H films, for the first time, we show gaseous molecules in nanovoids ({approx}2% volume fraction of tube-like nanoscale voids), and demonstrate that confinement on the nanometer scale generates NMR effects that have never been observed in macroscopic systems. In the same system we found the PL peak red shift. We suggest that highly strained bonds on the inner surfaces of the nanoscale voids form broad conduction-band tail states that are responsible for the PL red shift. We characterized the structural transition from a- to nc-Si as function of H-dilution, thickness and T{sub s} of both HW- and PE-CVD films using IR, Raman, PL, CPM/PDS and E{sub a} et al. We found not only the c-Si volume fraction but also the g.b. and microstructures play an important role in the properties of the i-layer and their solar cell performance. We found a narrow structural transition zone in which the bond-angle variation, {Delta}{Theta}, decreases from 10{sup o} to 8{sup o}. For nc-Si samples, we found a characteristic low energy PL peak and proved that is originated from the g.b. regions. Using micro-Raman, we found the structural non-uniformity in the mixed-phase solar cells that showed V{sub oc} enhancement after light soaking. Using micro-Raman, we also found the slight increase of crystallinity in M/{mu}c-Si/M devices after current forming.

Han, D.

2005-05-01T23:59:59.000Z

192

Ligand chemistry of titania precursor affects transient photovoltaic behavior in inverted organic solar cells  

E-Print Network (OSTI)

transient photovoltaic behavior in inverted organic solar cells Jong Bok Kim,1,a) Seokhoon Ahn,2,b) Seok JuLigand chemistry of titania precursor affects transient photovoltaic behavior in inverted organic solar cells Jong Bok Kim, Seokhoon Ahn, Seok Ju Kang, Colin Nuckolls, and Yueh-Lin Loo Citation: Appl

193

The Development of Semiconducting Materials for Organic Photovoltaics  

E-Print Network (OSTI)

Long-Term Thermal Stability of High-Efficiency Polymer SolarLong-Term Thermal Stability of High-Efficiency Polymer Solar

Douglas, Jessica D.

2013-01-01T23:59:59.000Z

194

Effect of organic salt doping on the performance of single layer bulk heterojunction organic solar cell  

Science Conference Proceedings (OSTI)

The effect of organic salt, tetrabutylammonium hexafluorophosphate (TBAPF{sub 6}) doping on the performance of single layer bulk heterojunction organic solar cell with ITO/MEHPPV:PCBM/Al structure was investigated where indium tin oxide (ITO) was used as anode, poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEHPPV) as donor, (6,6)-phenyl-C61 butyric acid methyl ester (PCBM) as acceptor and aluminium (Al) as cathode. In contrast to the undoped device, the electric field-treated device doped with TBAPF{sub 6} exhibited better solar cell performance under illumination with a halogen projector lamp at 100 mW/cm{sup 2}. The short circuit current density and the open circuit voltage of the doped device increased from 0.54 {mu}A/cm{sup 2} to 6.41 {mu}A/cm{sup 2} and from 0.24 V to 0.50 V, respectively as compared to those of the undoped device. The significant improvement was attributed to the increase of built-in electric field caused by accumulation of ionic species at the active layer/electrode interfaces. (author)

Yap, C.C.; Yahaya, M. [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia); Salleh, M.M. [Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia)

2011-01-15T23:59:59.000Z

195

Vehicle Technologies Office: Materials for High Efficiency Combustion...  

NLE Websites -- All DOE Office Websites (Extended Search)

High Efficiency Combustion Engines to someone by E-mail Share Vehicle Technologies Office: Materials for High Efficiency Combustion Engines on Facebook Tweet about Vehicle...

196

High efficiency compressor uses direct drive  

Science Conference Proceedings (OSTI)

This article focuses on the high efficiency of a compressor which uses only direct drive. This compressor was evaluated by judges and won Top Honors in the 1982 Chemical Processing magazine Vaaler Awards category of compressors, blowers and fans. Applications for the compressor include combustion air, process air and gas booster, incineration, fermentation, and vacuum filtration systems. In addition to a 50% reduction in power comsumption, the use of the compressor eliminated the need for a water seal, thus saving 200 gpm of water. And, since the elimination of the water seal reduced the necessary downtime for seal maintenance, on stream time was increased by 5%.

Not Available

1982-11-01T23:59:59.000Z

197

High efficiency inverter and ballast circuits  

SciTech Connect

A high efficiency push-pull inverter circuit employing a pair of relatively high power switching transistors is described. The switching on and off of the transistors is precisely controlled to minimize power losses due to common-mode conduction or due to transient conditions that occur in the process of turning a transistor on or off. Two current feed-back transformers are employed in the transistor base drives; one being saturable for providing a positive feedback, and the other being non-saturable for providing a subtractive feedback.

Nilssen, O.K.

1984-02-07T23:59:59.000Z

198

Building Technologies Office: High Efficiency, Low Emission Supermarket  

NLE Websites -- All DOE Office Websites (Extended Search)

High Efficiency, Low High Efficiency, Low Emission Supermarket Refrigeration Research Project to someone by E-mail Share Building Technologies Office: High Efficiency, Low Emission Supermarket Refrigeration Research Project on Facebook Tweet about Building Technologies Office: High Efficiency, Low Emission Supermarket Refrigeration Research Project on Twitter Bookmark Building Technologies Office: High Efficiency, Low Emission Supermarket Refrigeration Research Project on Google Bookmark Building Technologies Office: High Efficiency, Low Emission Supermarket Refrigeration Research Project on Delicious Rank Building Technologies Office: High Efficiency, Low Emission Supermarket Refrigeration Research Project on Digg Find More places to share Building Technologies Office: High

199

Current-matched high-efficiency, multijunction monolithic solar cells  

DOE Patents (OSTI)

The efficiency of a two-junction (cascade) tandem photovoltaic device is improved by adjusting (decreasing) the top cell thickness to achieve current matching. An example of the invention was fabricated out of Ga.sub.0.52 In.sub.0.48 P and GaAs. Additional lattice-matched systems to which the invention pertains include Al.sub.x Ga.sub.1-x /GaAS (x= 0.3-0.4), GaAs/Ge and Ga.sub.y In.sub.l-y P/Ga.sub.y+0.5 In.sub.0.5-y As (0

Olson, Jerry M. (Lakewood, CO); Kurtz, Sarah R. (Golden, CO)

1993-01-01T23:59:59.000Z

200

CdTe portfolio offers commercial ready high efficiency solar ...  

This characteristic is due partly to the single-phase nature of the absorber layer and the ease with which the CdTe source ... Wind Energy; Partners (27) Visual ...

Note: This page contains sample records for the topic "high-efficiency organic solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

High Efficiency Materials for Dye-Sensitized Solar Cells  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, Materials Science & Technology 2013. Symposium, Energy Storage III: Materials, Systems and Applications Symposium.

202

Aspects of charge recombination and charge transport in organic solar cells and light-emitting devices  

E-Print Network (OSTI)

In this thesis, aspects of charge reconbination and charge transport in organic solar cells and light-emitting devices are presented. These devices show promise relative to traditional inorganic semiconductors. We show ...

Difley, Seth

2010-01-01T23:59:59.000Z

203

Highly Efficient Modeling of Dynamic Coronal Loops  

E-Print Network (OSTI)

Observational and theoretical evidence suggests that coronal heating is impulsive and occurs on very small cross-field spatial scales. A single coronal loop could contain a hundred or more individual strands that are heated quasi-independently by nanoflares. It is therefore an enormous undertaking to model an entire active region or the global corona. Three-dimensional MHD codes have inadequate spatial resolution, and 1D hydro codes are too slow to simulate the many thousands of elemental strands that must be treated in a reasonable representation. Fortunately, thermal conduction and flows tend to smooth out plasma gradients along the magnetic field, so "0D models" are an acceptable alternative. We have developed a highly efficient model called Enthalpy-Based Thermal Evolution of Loops (EBTEL) that accurately describes the evolution of the average temperature, pressure, and density along a coronal strand. It improves significantly upon earlier models of this type--in accuracy, flexibility, and capability. It ...

Klimchuk, J A; Cargill, P J

2007-01-01T23:59:59.000Z

204

Research on stable, high-efficiency amorphous silicon multijunction modules  

DOE Green Energy (OSTI)

This report describes the progress made during Phase 1 of research and development program to obtain high-efficiency amorphous silicon alloy multijunction modules. Using a large-area deposition system, double-and triple-junction cells were made on stainless steel substrates of over 1 ft{sup 2} area with Ag and ZnO predeposited back reflector. Modules of over 1 ft{sup 2} were produced with between 9.2% and 9.9 initial aperture-area efficiencies as measured under a USSC Spire solar simulator. Efficiencies as measured under the NREL Spire solar simulator were found to be typically 15% to 18% lower. The causes for this discrepancy are now being investigated. The modules show about 15% degradation after 600 hours of one-sun illumination at 50{degrees}C. To optimize devices for higher stabilized efficiency, a new method was developed by which the performance of single-junction cells after long-term, one-sun exposure at 50{degrees}C can be predicted by exposing cells to short-term intense light at different temperatures. This method is being used to optimize the component cells of the multijunction structure to obtain the highest light-degraded efficiency.

Banerjee, A.; Chen, E.; Clough, R.; Glatfelter, T.; Guha, S.; Hammond, G.; Hopson, M.; Jackett, N.; Lycette, M.; Noch, J.; Palmer, T.; Pawlikiewicz, A.; Rosenstein, I.; Ross, R.; Wolf, D.; Xu, X.; Yang, J.; Younan, K.

1992-04-01T23:59:59.000Z

205

High Efficiency Electrical Energy Storage Using Reversible Solid ...  

Science Conference Proceedings (OSTI)

Symposium, Energy Storage III: Materials, Systems and Applications Symposium. Presentation Title, High Efficiency Electrical Energy Storage Using Reversible ...

206

High Efficiency Low Emission Supermarket Refrigeration Research Project  

Energy.gov (U.S. Department of Energy (DOE))

The U.S. Department of Energy (DOE) is currently conducting research into high efficiency, low emission supermarket refrigeration technologies.

207

Solar Trough Organic Rankine Electricity System (STORES) Stage 1: Power Plant Optimization and Economics; November 2000 -- May 2005  

DOE Green Energy (OSTI)

Report regarding a Stage 1 Study to further develop the concept of the Solar Trough Organic Rankine Cycle Electricity Systems (STORES).

Prabhu, E.

2006-03-01T23:59:59.000Z

208

Tailored Materials for High Efficiency CIDI Engines  

DOE Green Energy (OSTI)

The overall goal of the project, Tailored Materials for High Efficiency Compression Ignition Direct Injection (CIDI) Engines, is to enable the implementation of new combustion strategies, such as homogeneous charge compression ignition (HCCI), that have the potential to significantly increase the energy efficiency of current diesel engines and decrease fuel consumption and environmental emissions. These strategies, however, are increasing the demands on conventional engine materials, either from increases in peak cylinder pressure (PCP) or from increases in the temperature of operation. The specific objective of this project is to investigate the application of a new material processing technology, friction stir processing (FSP), to improve the thermal and mechanical properties of engine components. The concept is to modify the surfaces of conventional, low-cost engine materials. The project focused primarily on FSP in aluminum materials that are compositional analogs to the typical piston and head alloys seen in small- to mid-sized CIDI engines. Investigations have been primarily of two types over the duration of this project: (1) FSP of a cast hypoeutectic Al-Si-Mg (A356/357) alloy with no introduction of any new components, and (2) FSP of Al-Cu-Ni alloys (Alloy 339) by physically stirring-in various quantities of carbon nanotubes/nanofibers or carbon fibers. Experimental work to date on aluminum systems has shown significant increases in fatigue lifetime and stress-level performance in aluminum-silicon alloys using friction processing alone, but work to demonstrate the addition of carbon nanotubes and fibers into aluminum substrates has shown mixed results due primarily to the difficulty in achieving porosity-free, homogeneous distributions of the particulate. A limited effort to understand the effects of FSP on steel materials was also undertaken during the course of this project. Processed regions were created in high-strength, low-alloyed steels up to 0.5 in. deep that showed significant grain refinement and homogeneous microstructures favorable to increased fracture toughness and fatigue performance. The final tasks of the project demonstrated that the FSP concept can be applied to a relevant part geometry by fabricating diesel piston crowns with FSP regions applied selectively to the edge of the bowl rim. This area of the piston typically suffers from conditions at high PCP that cause severe thermal fatigue issues. It is expected that, given the data from coupon testing, the durability of pistons modified by FSP will allow much higher fatigue lifetime and potentially also greater resistance to elevated stress-level effects on fatigue.

Grant, G.J.; Jana, S.

2012-03-30T23:59:59.000Z

209

Novel Nanophosphors for High Efficiency Fluorescent Lamps  

SciTech Connect

This is the Final Report of the Novel Nanophosphors for High Efficiency Fluorescent Lamps, Department of Energy (DOE). The overall goal of this three-year program is to develop novel hybrid phosphors by coating commercially available lamp phosphors with highly stable wide band-gap nanocrystalline phosphors (NCP). The prime technical approach is the development of NCP quantum-splitting phosphor (QSP) and ultra-violet (UV) emitting phosphors with quantum efficiencies exceeding that of the conventional phosphors at 185 nm. The novel hybrid phosphors will increase the efficiency of the fluorescent lamps by up to 32%, enabling total energy savings of 0.26 quads, the reduction in the U.S. energy bill by $6.5 billion and the reduction of the annual carbon emission by 4.1 billion kilogram. Our work started by investigating through modeling calculations the requirement for the particle size of the NCP. Our work to develop suitable nanocrystalline phosphors started with the known oxide quantum splitting and UV emitting phosphors. We demonstrated several synthesis techniques for the production of high quality nanocrystalline materials that crystallizes in the desired phase and with the desired particle size. In collaboration with our subcontractor we demonstrated the feasibility for the manufacture of NC phosphors. We also demonstrated novel techniques of coating the NCP on the surface of micron sized phosphors. Our chief achievement pertains to the successful testing of the coated hybrid phosphor systems in linear fluorescent lamps. In linear fluorescent lamp tests, we have demonstrated up to 7% increase in the efficacy of hybrid phosphors over the conventional (uncoated) phosphors. We have also demonstrated the improvement in the lumen maintenance of the coated phosphors. A hybrid phosphor system based on the commercial red emitting phosphor, Y{sub 2}O{sub 3}:Eu{sup 3+} did not show the anticipated improvement in lamp efficacy. We explored the reasons for this observation, which are detailed in this report. Within the program we have carried out fundamental investigations into the physical processes that determine the quantum splitting behavior of the Pr{sup 3+} ion in solids. Specifically, we have investigated the quantum splitting luminescence of this ion in the LaPO{sub 4}, SrAl{sub 12}O{sub 19} and LiLaP{sub 4}O{sub 12} host lattices. In this final report we summarize the technical work completed under the Program, summarize our findings about the performance limits of the various technologies we investigated, and outline promising paths for future work.

Alok Srivatava

2007-03-31T23:59:59.000Z

210

Smart Solar Rooftops  

competing with fossil fuels on the energy market, so producing high-efficiency while maintaining a low cost is a major priority for the solar industry.

211

Solar | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

the ENERGY STAR refrigerators, high efficiency central air conditioning systems, and solar electric photovoltaic systems. This loan is being offered to encourage the...

212

A High Efficiency PSOFC/ATS-Gas Turbine Power System  

DOE Green Energy (OSTI)

A study is described in which the conceptual design of a hybrid power system integrating a pressurized Siemens Westinghouse solid oxide fuel cell generator and the Mercury{trademark} 50 gas turbine was developed. The Mercury{trademark} 50 was designed by Solar Turbines as part of the US. Department of Energy Advanced Turbine Systems program. The focus of the study was to develop the hybrid power system concept that principally would exhibit an attractively-low cost of electricity (COE). The inherently-high efficiency of the hybrid cycle contributes directly to achieving this objective, and by employing the efficient, power-intensive Mercury{trademark} 50, with its relatively-low installed cost, the higher-cost SOFC generator can be optimally sized such that the minimum-COE objective is achieved. The system cycle is described, major system components are specified, the system installed cost and COE are estimated, and the physical arrangement of the major system components is discussed. Estimates of system power output, efficiency, and emissions at the system design point are also presented. In addition, two bottoming cycle options are described, and estimates of their effects on overall-system performance, cost, and COE are provided.

W.L. Lundberg; G.A. Israelson; M.D. Moeckel; S.E. Veyo; R.A. Holmes; P.R. Zafred; J.E. King; R.E. Kothmann

2001-02-01T23:59:59.000Z

213

High Efficiency, Illumination Quality OLEDs for Lighting  

SciTech Connect

The goal of the program was to demonstrate a 45 lumen per watt white light device based upon the use of multiple emission colors through the use of solution processing. This performance level is a dramatic extension of the team's previous 15 LPW large area illumination device. The fundamental material system was based upon commercial polymer materials. The team was largely able to achieve these goals, and was able to deliver to DOE a 90 lumen illumination source that had an average performance of 34 LPW a 1000 cd/m{sup 2} with peak performances near 40LPW. The average color temperature is 3200K and the calculated CRI 85. The device operated at a brightness of approximately 1000cd/m{sup 2}. The use of multiple emission colors particularly red and blue, provided additional degrees of design flexibility in achieving white light, but also required the use of a multilayered structure to separate the different recombination zones and prevent interconversion of blue emission to red emission. The use of commercial materials had the advantage that improvements by the chemical manufacturers in charge transport efficiency, operating life and material purity could be rapidly incorporated without the expenditure of additional effort. The program was designed to take maximum advantage of the known characteristics of these material and proceeded in seven steps. (1) Identify the most promising materials, (2) assemble them into multi-layer structures to control excitation and transport within the OLED, (3) identify materials development needs that would optimize performance within multilayer structures, (4) build a prototype that demonstrates the potential entitlement of the novel multilayer OLED architecture (5) integrate all of the developments to find the single best materials set to implement the novel multilayer architecture, (6) further optimize the best materials set, (7) make a large area high illumination quality white OLED. A photo of the final deliverable is shown. In 2003, a large area, OLED based illumination source was demonstrated that could provide light with a quality, quantity, and efficiency on par with what can be achieved with traditional light sources. The demonstration source was made by tiling together 16 separate 6-inch x 6-inch blue-emitting OLEDs. The efficiency, total lumen output, and lifetime of the OLED based illumination source were the same as what would be achieved with an 80 watt incandescent bulb. The devices had an average efficacy of 15 LPW and used solution-processed OLEDs. The individual 6-inch x 6-inch devices incorporated three technology strategies developed specifically for OLED lighting -- downconversion for white light generation, scattering for outcoupling efficiency enhancement, and a scalable monolithic series architecture to enable large area devices. The downconversion approach consists of optically coupling a blue-emitting OLED to a set of luminescent layers. The layers are chosen to absorb the blue OLED emission and then luminescence with high efficiency at longer wavelengths. The composition and number of layers are chosen so that the unabsorbed blue emission and the longer wavelength re-emission combine to make white light. A downconversion approach has the advantage of allowing a wide variety of colors to be made from a limited set of blue emitters. In addition, one does not have to carefully tune the emission wavelength of the individual electro-luminescent species within the OLED device in order to achieve white light. The downconversion architecture used to develop the 15LPW large area light source consisted of a polymer-based blue-emitting OLED and three downconversion layers. Two of the layers utilized perylene based dyes from BASF AG of Germany with high quantum efficiency (>98%) and one of the layers consisted of inorganic phosphor particles (Y(Gd)AG:Ce) with a quantum efficiency of {approx}85%. By independently varying the optical density of the downconversion layers, the overall emission spectrum could be adjusted to maximize performance for lighting (e.g. blackbody temp

Joseph Shiang; James Cella; Kelly Chichak; Anil Duggal; Kevin Janora; Chris Heller; Gautam Parthasarathy; Jeffery Youmans; Joseph Shiang

2008-03-31T23:59:59.000Z

214

Available Technologies: Thinner Film Silicon Solar Cells  

Berkeley Lab scientists have designed a new approach to create highly efficient thin film silicon solar cells. This technology promises to lower solar cell material ...

215

High Efficiency Low Emission Supermarket Refrigeration Research Project |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

High Efficiency Low Emission Supermarket High Efficiency Low Emission Supermarket Refrigeration Research Project High Efficiency Low Emission Supermarket Refrigeration Research Project The U.S. Department of Energy (DOE) is currently conducting research into high efficiency, low emission supermarket refrigeration technologies. Project Description The project involves the development of a supermarket refrigeration system that can reduce greenhouse gas emissions and energy consumption when compared to existing systems. The challenge is to design a system that is capable of achieving low refrigerant leak rates while significantly reducing both the energy consumption and the refrigerant charge size. Project Partners Research is being undertaken between DOE and Oak Ridge National Laboratory. Project Goals

216

High-Efficiency Photovoltaics at Thin Film Costs  

Time (Years) 0-+ 5. 10. 15. 20. 25. Opportunity. Technology. ... • 15 years renewable energy business development ... High-Efficiency Photovoltaics at ...

217

Complex Oxides for Highly Efficient Solid-State Energy ...  

Complex Oxides for Highly Efficient Solid-State Energy ... Using complex oxides to directly convert thermal to electrical energy is both ... Thermal P ...

218

Low resistance thin film organic solar cell electrodes  

SciTech Connect

A method which lower the series resistance of photosensitive devices includes providing a transparent film of a first electrically conductive material arranged on a transparent substrate; depositing and patterning a mask over the first electrically conductive material, such that openings in the mask have sloping sides which narrow approaching the substrate; depositing a second electrically conductive material directly onto the first electrically conductive material exposed in the openings of the mask, at least partially filling the openings; stripping the mask, leaving behind reentrant structures of the second electrically conductive material which were formed by the deposits in the openings of the mask; after stripping the mask, depositing a first organic material onto the first electrically conductive material in between the reentrant structures; and directionally depositing a third electrically conductive material over the first organic material deposited in between the reentrant structures, edges of the reentrant structures aligning deposition so that the third electrically conductive material does not directly contact the first electrically conductive material, and does not directly contact the second electrically conductive material.

Forrest, Stephen (Princeton, NJ); Xue, Jiangeng (Piscataway, NJ)

2008-01-01T23:59:59.000Z

219

High efficiency light emitting diode with anisotropically etched GaN-sapphire interface  

E-Print Network (OSTI)

High efficiency light emitting diode with anisotropically etched GaN- sapphire interface M. H. Lo and optimization of a light-emitting diode projection micro-stereolithography three-dimensional manufacturingGaN micro-light emitting diodes Appl. Phys. Lett. 101, 231110 (2012) A bright cadmium-free, hybrid organic

220

Novel High Efficiency Photovoltaic Devices Based on the III-N Material System: Final Technical Report, 7 December 2005 - 29 August 2008  

DOE Green Energy (OSTI)

The research shows that InGaN material system can be used to realize high-efficiency solar cells, making contributions to growth, modeling, understanding of loss mechanisms, and process optimization.

Hornsberg, C.; Doolittle, W. A.; Ferguson, I.

2008-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "high-efficiency organic solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Scientists at ALS Find New Path to More Efficient Organic Solar Cells  

NLE Websites -- All DOE Office Websites (Extended Search)

Scientists at ALS Find New Path to Scientists at ALS Find New Path to More Efficient Organic Solar Cells Scientists at ALS Find New Path to More Efficient Organic Solar Cells Print Monday, 07 January 2013 00:00 Harald Ade, a physicist at North Carolina State University, led a study at the Advanced Light Source that revealed a second pathway to improved performances of polymer/organic solar cells. Whereas the first pathway demands crystals of ultrapure domains, the new pathway shows that impure domains if sufficiently small can also lead to improved photovoltaic performances. Also working on this project were Brian Collins, Zhe Li, John Tumbleston, Eliot Gann and Christopher McNeill. Read the News Release Molecular view of polymer/fullerene solar film showing an interface between acceptor and donor domains. Red dots are PC71BM molecules and blue lines represent PTB7 chains. Excitons are shown as yellow dots, purple dots are electrons and green dots represent holes

222

Organization of Energetic Particles by the Solar Wind Structure During the Declining to Minimum Phase of Solar Cycle 23  

E-Print Network (OSTI)

the longitude distribution of solar energetic particles. J.shocks in deter- mining solar energetic particle abundances.J.E. , Dwyer, J.R. : 2006a, Solar cycle variations in the

2010-01-01T23:59:59.000Z

223

Advanced high efficiency concentrator cells. Final subcontractor report, 1 October 1988--31 March 1990  

DOE Green Energy (OSTI)

This report describes research to develop the technology needed to demonstrate a monolithic, multijunction, two-terminal, concentrator solar cell with a terrestrial power conversion efficiency greater than 35%. Under three previous subcontracts, Varian developed many of the aspects of a technology needed to fabricate very high efficiency concentrator cells. The current project was aimed at exploiting the new understanding of high efficiency solar cells. Key results covered in this report are as follows. (1) A 1.93-eV AlGaAs/1.42-eV GaAs metal-interconnected cascade cell was manufactured with a one-sun efficiency at 27.6% at air mass 1.5 (AM1.5) global. (2) A 1.0eV InGaAs cell was fabricated on the ``reverse`` side of a low-doped GaAs substrate with a one-sun efficiency of 2.5% AM1.5 diffuse and a short-circuit current of 14.4 mA/cm{sup 2}. (3) Small-scale manufacturing of GaAs p/n concentrator cells was attempted and obtained an excellent yield of high-efficiency cells. (4) Grown-in tunnel junction cell interconnects that are transparent and thermally stable using C and Si dopants were developed. 10 refs.

Gale, R. [Varian Associates, Inc., Palo Alto, CA (United States). Varian Research Center

1992-06-01T23:59:59.000Z

224

Analysis of Organic Rankine Cycle for Low and Medium Grade Heat Source  

Science Conference Proceedings (OSTI)

Organic Rankine cycle (ORC) is an effective technique to generate power from low and medium temperature heat source, including industrial waste heat, solar heat, geothermal and biomass etc. Advantages of ORC are high efficiency, simple system, environment ... Keywords: organic Rankine cycle, new energy, waste heat recovery

Zhonghe Han, Yida Yu

2012-07-01T23:59:59.000Z

225

Solar  

Energy.gov (U.S. Department of Energy (DOE))

The U.S. Department of Energy (DOE) leads a large network of researchers and other partners to deliver innovative solar photovoltaic and concentrating solar power technologies that will make solar...

226

High efficiency pulse motor drive for robotic propulsion  

E-Print Network (OSTI)

The goal of this research is to improve the power efficiency of robotic locomotion through the use of series elastic actuation, with a focus on swimming motion. To achieve high efficiency, electromechanical drives need to ...

Sun, Zhen, M.S. Massachusetts Institute of Technology

2013-01-01T23:59:59.000Z

227

Techniques for high-efficiency outphasing power amplifiers  

E-Print Network (OSTI)

A trade-off between linearity and efficiency exists in conventional power amplifiers (PAs). The outphase amplifying concept overcomes this trade-off by enabling the use of high efficiency, non-linear power amplifiers for ...

Godoy, Philip (Philip Andrew)

2011-01-01T23:59:59.000Z

228

III-V High-Efficiency Multijunction Photovoltaics (Fact Sheet)  

Science Conference Proceedings (OSTI)

Capabilities fact sheet that includes scope, core competencies and capabilities, and contact/web information for III-V High-Efficiency Multijunction Photovoltaics at the National Center for Photovoltaics.

Not Available

2011-06-01T23:59:59.000Z

229

Highly efficient blue polyfluorene-based polymer light-emitting...  

NLE Websites -- All DOE Office Websites (Extended Search)

of Physics Volume 42 Pagination 5 Abstract A highly efficient blue polymer light-emitting diode based on poly(9,9-di(2-(2-(2-methoxy-ethoxy)ethoxy)ethyl)fluorenyl-2,7-diyl)...

230

Design of high efficiency Mid IR QCL lasers  

E-Print Network (OSTI)

The proposed research is a study of designing high-efficiency Mid-IR quantum cascade lasers (QCL). This thesis explores "injector-less" designs for achieving lower voltage defects and improving wall plug efficiencies through ...

Hsu, Allen Long

2008-01-01T23:59:59.000Z

231

Efficient Organic Excitonic Solar Cells with Carbon Nanotubes Replacing In2O3:Sn as the Transparent Electrode (Presentation)  

DOE Green Energy (OSTI)

The conclusions of this report are that: (1) organic solar cells with efficiencies of up to 1.43% conversion efficiency that use no ITO and no PEDOT:PSS, are demonstrated; (2) a cell without ITO, but with PEDOT:PSS gave 2.6% conversion efficiency; (3) due to porous nature of SWCNT substrates, optimization of the active layer is essential; and (4) SWCNT electrodes bring one step closer the goal of a fully printable, organic solar cell.

van de Lagemaat, J.; Barnes, T.; Rumbles, G.; Shaheen, S.; Coutts, T. J.; Weeks, C.; Glatkowski, P.; Levitsky, I.; Peltola, J.

2006-05-01T23:59:59.000Z

232

The Design of Organic Polymers and Small Molecules to Improve the Efficiency of Excitonic Solar Cells  

E-Print Network (OSTI)

broadly across the solar spectrum, have functional groupsbroadly across the solar spectrum. Open circuit voltages (Vabsorbing 80% of the solar spectrum from 350-900 nm would

Armstrong, Paul Barber

2010-01-01T23:59:59.000Z

233

Simulation of geometry and shadow effects in 3D organic polymer solar cells.  

E-Print Network (OSTI)

??Rising inventory levels of Solar panels and new production capacity is driving solar PV prices lower and thereby, bringing solar energy closer to grid price… (more)

Parikh, Mihir Prakashbhai

2013-01-01T23:59:59.000Z

234

Solution processable organic polymers and small molecules for bulk-heterojunction solar cells: A review  

Science Conference Proceedings (OSTI)

Solution processed bulk heterojunction (BHJ) organic solar cells (OSCs) have gained wide interest in past few years and are established as one of the leading next generation photovoltaic technologies for low cost power production. Power conversion efficiencies up to 6% and 6.5% have been reported in the literature for single layer and tandem solar cells, respectively using conjugated polymers. A recent record efficiency about 8.13% with active area of 1.13 cm{sup 2} has been reported. However Solution processable small molecules have been widely applied for photovoltaic (PV) devices in recent years because they show strong absorption properties, and they can be easily purified and deposited onto flexible substrates at low cost. Introducing different donor and acceptor groups to construct donor--acceptor (D--A) structure small molecules has proved to be an efficient way to improve the properties of organic solar cells (OSCs). The power conversion efficiency about 4.4 % has been reported for OSCs based on the small molecules. This review deals with the recent progress of solution processable D--A structure small molecules and discusses the key factors affecting the properties of OSCs based on D--A structure small molecules: sunlight absorption, charge transport and the energy level of the molecules.

Sharma, G. D. [Physics Department, Molecular Electronic and Optoelectronic Device Laboratory JNV University, Jodhpur (Raj.) 342005 (India)

2011-10-20T23:59:59.000Z

235

Power Laws in Solar Flares: Self-Organized Criticality or Turbulence?  

E-Print Network (OSTI)

We study the time evolution of Solar Flares activity by looking at the statistics of quiescent times $\\tau_{L}$ between successive bursts. The analysis of 20 years of data reveals a power law distribution with exponent $\\alpha \\simeq 2.4$ which is an indication of complex dynamics with long correlation times. The observed scaling behavior is in contradiction with the Self-Organized Criticality models of Solar Flares which predict Poisson-like statistics. Chaotic models, including the destabilization of the laminar phases and subsequent restabilization due to nonlinear dynamics, are able to reproduce the power law for the quiescent times. In the case of the more realistic Shell Model of MHD turbulence we are able to reproduce all the observed distributions.

Guido Boffetta; Vincenzo Carbone; Paolo Giuliani; Pierluigi Veltri; Angelo Vulpiani

1999-04-23T23:59:59.000Z

236

Heat Transfer Interface for Thermo-Solar Energy - Energy ...  

Technology Marketing Summary Alex Zettl of Berkeley Lab has invented a high efficiency solar energy collector and converter. By addressing both solar absorption and ...

237

Development of nanostructured and surface modified semiconductors for hybrid organic-inorganic solar cells.  

DOE Green Energy (OSTI)

Solar energy conversion is increasingly being recognized as one of the principal ways to meet future energy needs without causing detrimental environmental impact. Hybrid organic-inorganic solar cells (SCs) are attracting particular interest due to the potential for low cost manufacturing and for use in new applications, such as consumer electronics, architectural integration and light-weight sensors. Key materials advantages of these next generation SCs over conventional semiconductor SCs are in design opportunities--since the different functions of the SCs are carried out by different materials, there are greater materials choices for producing optimized structures. In this project, we explore the hybrid organic-inorganic solar cell system that consists of oxide, primarily ZnO, nanostructures as the electron transporter and poly-(3-hexylthiophene) (P3HT) as the light-absorber and hole transporter. It builds on our capabilities in the solution synthesis of nanostructured semiconducting oxide arrays to this photovoltaic (PV) technology. The three challenges in this hybrid material system for solar applications are (1) achieving inorganic nanostructures with critical spacing that matches the exciton diffusion in the polymer, {approx} 10 nm, (2) infiltrating the polymer completely into the dense nanostructure arrays, and (3) optimizing the interfacial properties to facilitate efficient charge transfer. We have gained an understanding and control over growing oriented ZnO nanorods with sub-50 nm diameters and the required rod-to-rod spacing on various substrates. We have developed novel approaches to infiltrate commercially available P3HT in the narrow spacing between ZnO nanorods. Also, we have begun to explore ways to modify the interfacial properties. In addition, we have established device fabrication and testing capabilities at Sandia for prototype devices. Moreover, the control synthesis of ZnO nanorod arrays lead to the development of an efficient anti-reflection coating for multicrystalline Si solar cells. An important component of this project is the collaboration with Dr. Dave Ginley's group at NREL. The NREL efforts, which are funded by NREL's LDRD program, focus on measuring device performance, external quantum efficiency, photoconductance through highly specialized non-contact time-resolved microwave conductivity (TRMC) measurements, and vapor phase deposition of oxide materials. The close collaboration with NREL enables us to enter this competitive field in such short time. Joint publications and presentations have resulted from this fruitful collaboration. To this date, 5 referred journal papers have resulted from this project, with 2 more in preparation. Several invited talks and numerous contributed presentations in international conferences are also noted. Sandia has gained the reputation of being one of forefront research groups on nanostructured hybrid solar cells.

Hsu, Julia, W. P.

2008-09-01T23:59:59.000Z

238

Solar Power Generation Development  

DOE Green Energy (OSTI)

This project centered on creating a solar cell prototype enabling significant reductions in module cost and increases in module efficiency. Low cost was addressed by using plentiful organic materials that only comprise 16% of the total module cost, and by leveraging building integrated PV concepts that reduce the cost of key module components to zero. High efficiency was addressed by implementing multiband organic PV, low cost spectral splitting, and possibly integrating photovoltaic and photothermal mechanisms. This research has contributed to the design of multiband organic PV, and the sealing of organic PV cells. If one assumes that the aggregate multiband efficiency can reach 12%, projected cost would be $0.97/W. If the sealing technology enables 10 to 20 year lifetimes, the LCOE will match that of domestic coal. The final report describes progress towards these goals.

Robert L. Johnson Jr.; Gary E. Carver

2011-10-28T23:59:59.000Z

239

Department of Energy Lauds Highly Efficient Industrial Technology |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Lauds Highly Efficient Industrial Technology Lauds Highly Efficient Industrial Technology Department of Energy Lauds Highly Efficient Industrial Technology November 30, 2007 - 4:45pm Addthis DOE Celebrates One-Year Anniversary of Operation of the Energy Efficient "Super Boiler" WASHINGTON, DC - Representing important technology transfer from Department of Energy (DOE) labs to the marketplace, DOE today announced the successful one-year operation of the first generation "Super Boiler," which can deliver 94 percent thermal efficiency, while producing fewer emissions than conventional boiler technologies. By 2020, this technology could save more than 185 trillion British Thermal Units (Btus) of energy - equivalent to the natural gas consumed by more than two million households. The

240

Home Performance with Energy Star High Efficiency Measure Incentive (HEMI)  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Home Performance with Energy Star High Efficiency Measure Incentive Home Performance with Energy Star High Efficiency Measure Incentive (HEMI) Home Performance with Energy Star High Efficiency Measure Incentive (HEMI) < Back Eligibility Residential Savings Category Heating & Cooling Commercial Heating & Cooling Heating Home Weatherization Commercial Weatherization Cooling Appliances & Electronics Sealing Your Home Ventilation Manufacturing Commercial Lighting Lighting Water Heating Maximum Rebate $3,000 Program Info State New York Program Type State Rebate Program Rebate Amount 10% of project costs Provider New York State Energy Research and Development Authority The New York State Research and Development Authority (NYSERDA) offers an incentive for homeowners of 1-4 homes that participate in the Home Performance with Energy Star program. The program entitles the participant

Note: This page contains sample records for the topic "high-efficiency organic solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Laclede Gas Company - Residential High Efficiency Heating Rebate Program |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Residential High Efficiency Heating Rebate Residential High Efficiency Heating Rebate Program Laclede Gas Company - Residential High Efficiency Heating Rebate Program < Back Eligibility Multi-Family Residential Residential Savings Category Heating & Cooling Commercial Heating & Cooling Heating Appliances & Electronics Water Heating Maximum Rebate Heating System: 2 maximum Programmable Thermostats: 2 maximum Multi-Family Property Owners: 50 thermostat rebates, 50 furnace rebates over the life of the program Program Info State Missouri Program Type Utility Rebate Program Rebate Amount Gas Furnace: $150 - $200 Gas Boiler: $150 Programmable Setback Thermostat: $25 Gas Water Heater: $50 - $200 Provider Laclede Gas Company Laclede Gas Company offers various rebates to residential customers for investing in energy efficient equipment and appliances. Residential

242

Department of Energy Lauds Highly Efficient Industrial Technology |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Department of Energy Lauds Highly Efficient Industrial Technology Department of Energy Lauds Highly Efficient Industrial Technology Department of Energy Lauds Highly Efficient Industrial Technology November 30, 2007 - 4:45pm Addthis DOE Celebrates One-Year Anniversary of Operation of the Energy Efficient "Super Boiler" WASHINGTON, DC - Representing important technology transfer from Department of Energy (DOE) labs to the marketplace, DOE today announced the successful one-year operation of the first generation "Super Boiler," which can deliver 94 percent thermal efficiency, while producing fewer emissions than conventional boiler technologies. By 2020, this technology could save more than 185 trillion British Thermal Units (Btus) of energy - equivalent to the natural gas consumed by more than two million households. The

243

Southwest Gas Corporation - Commercial High-Efficiency Equipment Rebate  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Southwest Gas Corporation - Commercial High-Efficiency Equipment Southwest Gas Corporation - Commercial High-Efficiency Equipment Rebate Program Southwest Gas Corporation - Commercial High-Efficiency Equipment Rebate Program < Back Eligibility Commercial Industrial Savings Category Other Appliances & Electronics Commercial Weatherization Commercial Heating & Cooling Water Heating Maximum Rebate General: 50% of price Boiler Steam Trap: 25% of price Program Info State Arizona Program Type Utility Rebate Program Rebate Amount Modulating Burner Control: $10,000 Boiler O2 Trim Control Pad: $10,000 Boiler Steam Trap: $250 Non-condensing Boiler: $1/MBtuh Condensing Boiler: $1.25/MBtuh Storage Water Heater: 50% of cost, up to $1,100 Tankless Water Heater: 50% of cost, up to $450 Griddle: 50% of cost, up to $600 Fryer: 50% of cost, up to $1,350

244

SunShot Initiative: High-Efficiency Thermal Energy Storage System for CSP  

NLE Websites -- All DOE Office Websites (Extended Search)

High-Efficiency Thermal Energy Storage System for CSP High-Efficiency Thermal Energy Storage System for CSP ANL logo Photo of a black and white porous material magnified 50 times by a microscope. Microstructure of the highly thermal conductive foam that will be used for the prototype TES system. Image from ANL Argonne National Laboratory and project partner Ohio Aerospace Institute, under the National Laboratory R&D competitive funding opportunity, will design, develop, and test a prototype high-temperature and high-efficiency thermal energy storage (TES) system with rapid charging and discharging times. By increasing the efficiency of TES systems, this project aims to lower the capital costs of concentrating solar power (CSP) systems. Approach The research team is developing and evaluating a novel approach for TES at temperatures greater than 700ËšC for CSP systems. The approach uses high thermal conductivity and high-porosity graphite foams infiltrated with a phase change material (PCM) to provide TES in the form of latent heat.

245

Second Generation Biofuels: High-Efficiency Microalgae for Biodiesel Production  

E-Print Network (OSTI)

it as chemical energy. This presents a route for renewable and carbon-neutral fuel production. However, currentSecond Generation Biofuels: High-Efficiency Microalgae for Biodiesel Production Peer M. Schenk that are not only renewable, but also capable of sequestering atmospheric CO2. Currently, nearly all renewable

Kudela, Raphael M.

246

Exploratory Research for New Solar Electric Technologies  

SciTech Connect

We will review highlights of exploratory research for new PV technologies funded by the DOE Solar Energy Technologies Program through NREL and its Photovoltaic Exploratory Research Project. The goal for this effort is highlighted in the beginning of the Solar Program Multi-Year Technical Plan by Secretary of Energy Spencer Abraham's challenge to leapfrog the status quo by pursuing research having the potential to create breakthroughs. The ultimate goal is to create solar electric technologies for achieving electricity costs below 5 cents/kWh. Exploratory research includes work on advanced photovoltaic technologies (organic and ultra-high efficiency solar cells for solar concentrators) as well as innovative approaches to emerging and mature technologies (e.g., crystalline silicon).

McConnell, R.; Matson, R.

2005-01-01T23:59:59.000Z

247

Exploratory Research for New Solar Electric Technologies  

DOE Green Energy (OSTI)

We will review highlights of exploratory research for new PV technologies funded by the DOE Solar Energy Technologies Program through NREL and its Photovoltaic Exploratory Research Project. The goal for this effort is highlighted in the beginning of the Solar Program Multi-Year Technical Plan by Secretary of Energy Spencer Abraham's challenge to leapfrog the status quo by pursuing research having the potential to create breakthroughs. The ultimate goal is to create solar electric technologies for achieving electricity costs below 5 cents/kWh. Exploratory research includes work on advanced photovoltaic technologies (organic and ultra-high efficiency solar cells for solar concentrators) as well as innovative approaches to emerging and mature technologies (e.g., crystalline silicon).

McConnell, R.; Matson, R.

2005-01-01T23:59:59.000Z

248

Developing a Highly Efficient Multi-use Special Economic Zone in India  

NLE Websites -- All DOE Office Websites (Extended Search)

Developing a Highly Efficient Multi-use Special Economic Zone in India Developing a Highly Efficient Multi-use Special Economic Zone in India Speaker(s): Jagadeesh Taluri Kushboo Modgil Date: June 3, 2010 - 12:00pm Location: 90-3122 LBNL is collaborating with Metro Valley to create the most energy efficient built environment in India. The proposed project is an ITES (Information Technology Enabled Services) Special Economic Zone which is a multi-tenanted campus consisting of work and support spaces for companies involved in research or knowledge processing. The goal of the project reaches beyond an energy efficient built environment for the Knowledge Industry to sustainability in the broadest sense: a sustainable environment, not just from the point of view of energy consumption, but also relative to the people who use it, the organizations that inhabit it,

249

Design of Bulk Nanocomposites as High Efficiency Thermoelectric Materials |  

Office of Science (SC) Website

Design of Bulk Nanocomposites as High Design of Bulk Nanocomposites as High Efficiency Thermoelectric Materials Energy Frontier Research Centers (EFRCs) EFRCs Home Centers Research Science Highlights Highlight Archives News & Events Publications Contact BES Home 04.27.12 Design of Bulk Nanocomposites as High Efficiency Thermoelectric Materials Print Text Size: A A A RSS Feeds FeedbackShare Page Scientific Achievement A newly synthesized bulk thermoelectric material that contains nanocrystals with the same orientation and structure as the host material breaks thermoelectric efficiency records by blocking thermal, but not electrical, conductivity. Significance and Impact A new strategy to design inexpensive materials that more efficiently convert heat to electricity. Research Details Thermoelectric materials directly generate electrical power from heat, but

250

A Perspective on the Future of High Efficiency Engines  

SciTech Connect

New fuel economy standards and emissions regulations are accelerating the development of new engine technologies, sensors, and on-board computing. These developments will enable unprecedented engine control, which will in turn enable real-world implementations of low temperature combustion, high-speed controls, and other high efficiency engine technologies. With this expanded flexibility in engine design and control, the challenge will now be the exponential increase in the design and calibration space and the need for the development of new simulations, optimization methods, and self-learning control methodologies. This manuscript provides historical and future perspectives on the opportunities and challenges of this unparalleled technology growth on the next generation of high efficiency engines.

Wagner, Robert M [ORNL; Curran, Scott [ORNL; Green Jr, Johney Boyd [ORNL

2013-01-01T23:59:59.000Z

251

Basic studies of 3-5 high efficiency cell components. Annual subcontract report, 15 August 1989--14 August 1990  

DOE Green Energy (OSTI)

This project`s objective is to improve our understanding of the generation, recombination, and transport of carriers within III-V homo- and heterostructures. The research itself consists of fabricating and characterizing solar cell ``building blocks`` such as junctions and heterojunctions as well as basic measurements of material parameters. A significant effort is also being directed at characterizing loss mechanisms in high-quality, III-V solar cells fabricated in industrial research laboratories throughout the United States. The project`s goal is to use our understanding of the device physics of high-efficiency cell components to maximize cell efficiency. A related goal is the demonstration of new cell structures fabricated by molecular beam epitaxy (MBE). The development of measurement techniques and characterization methodologies is also a project objective. This report describes our progress during the fifth and final year of the project. During the past five years, we`ve teamed a great deal about heavy doping effects in p{sup +} and n{sup +} GaAs and have explored their implications for solar cells. We have developed an understanding of the dominant recombination losses in present-day, high-efficiency cells. We`ve learned to appreciated the importance of recombination at the perimeter of the cell and have developed techniques for chemically passivating such edges. Finally, we`ve demonstrated that films grown by molecular beam epitaxy are suitable for high-efficiency cell research.

Lundstrom, M.S.; Melloch, M.R.; Pierret, R.F.; Carpenter, M.S.; Chuang, H.L.; Dodd, P.E.; Keshavarzi, A.; Klausmeier-Brown, M.E.; Lush, G.B.; Stellwag, T.B. [Purdue Univ., Lafayette, IN (United States)

1993-01-01T23:59:59.000Z

252

Titania Coated Silica Microspheres for High Efficiency Dye ...  

Science Conference Proceedings (OSTI)

These microspheres, if used in DSSCs, can boost the efficiency of solar cell ... In- situ Characterization of Intercalation-induced Damage of High Purity Graphite ...

253

Sandia National Laboratories High Efficiency Multiple-Junction ...  

Sandia National Laboratories TECHNOLOGY SUMMARY Single junction solar cells have limited efficiency and fail to extract maximum energy from photons outside of a specific

254

Development and Demonstration of a New-Generation High Efficiency...  

NLE Websites -- All DOE Office Websites (Extended Search)

unit resulting in: Grid tie enabled using commercial solar photovoltaic - inverter Integrated feed gas compressor, water system and - gas quality monitoring Onboard...

255

Inverted organic solar cells comprising a solution-processed cesium fluoride interlayer  

SciTech Connect

We investigate the influence of solution-processed cesium fluoride (CsF) interlayers on the performance of inverted polymer solar cells comprising a blend of poly(3-hexylthiophene-2,5-diyl):[6,6]-phenyl C{sub 61}-butyric acid methyl ester. The thickness of the CsF layer is optimized in terms of current-voltage characteristics by a variation of the solid content in solution. Capacitance-voltage characteristics reveal a shift of the built-in voltage at the cathode interface by about 0.3 V as compared to devices without a CsF layer, giving rise to an increase in open-circuit voltage by the same value. The vertical distribution of Cs{sup +} and F{sup +} ions is studied by secondary ion mass spectroscopy, indicating a strong diffusion of the alkaline fluoride into the organic layer stack.

Reinhard, Manuel; Zhang Zhenhao; Colsmann, Alexander; Lemmer, Uli [Light Technology Institute, Karlsruhe Institute of Technology (KIT), Engesserstrasse 13, 76131 Karlsruhe (Germany); Hanisch, Jonas; Ahlswede, Erik [Zentrum fuer Sonnenenergie- und Wasserstoff-Forschung Baden-Wuerttemberg, Industriestrasse 6, 70565 Stuttgart (Germany)

2011-01-31T23:59:59.000Z

256

Charge density dependent nongeminate recombination in organic bulk heterojunction solar cells  

E-Print Network (OSTI)

Apparent recombination orders exceeding the value of two expected for bimolecular recombination have been reported for organic solar cells in various publications. Two prominent explanations are bimolecular losses with a carrier concentration dependent prefactor due to a trapping limited mobility, and protection of trapped charge carriers from recombination by a donor--acceptor phase separation until reemission from these deep states. In order to clarify which mechanism is dominant we performed temperature and illumination dependent charge extraction measurements under open circuit as well as short circuit conditions at poly(3-hexylthiophene-2,5-diyl):[6,6]-phenyl-C$_{61}$butyric acid methyl ester (P3HT:PC$_{61}$BM) and PTB7:PC$_{71}$BM (Poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl

D. Rauh; C. Deibel; V. Dyakonov

2012-03-27T23:59:59.000Z

257

Final Technical Progress Report: High-Efficiency Low-Cost Thin-Film GaAs Photovoltaic Module Development Program; July 14, 2010 - January 13, 2012  

DOE Green Energy (OSTI)

This is the final technical progress report of the High-Efficiency Low-Cost Thin-Film GaAs Photovoltaic Module Development Program. Alta Devices has successfully completed all milestones and deliverables established as part of the NREL PV incubator program. During the 18 months of this program, Alta has proven all key processes required to commercialize its solar module product. The incubator focus was on back end process steps directed at conversion of Alta's high quality solar film into high efficiency 1-sun PV modules. This report describes all program deliverables and the work behind each accomplishment.

Mattos, L.

2012-03-01T23:59:59.000Z

258

Projects Move Solar Technologies to Commercial Scale  

Science Conference Proceedings (OSTI)

Jan 21, 2010 ... Solar Junction Corp. (San Jose, California) A manufacturing process will be developed to produce a very high efficiency multi-junction cell.

259

DOE Solar Decathlon: 2007 Teams - Cornell University  

NLE Websites -- All DOE Office Websites (Extended Search)

2007 Solar Decathlon house. The Cornell house is designed to be highly efficient and easy to maintain and upgrade. Download Construction Drawings (Zip 24 MB) Neither the United...

260

Introduction to organic solar cells As the need for renewable energy sources becomes more urgent, photovoltaic en-  

E-Print Network (OSTI)

between two electrodes, one transparent and one reflecting. The glass substrate is coated with indium-tin-oxide indium tin oxide JD current density in dark JL current density under illumination Jn(p) electron (holeCHAPTER ONE Introduction to organic solar cells Summary As the need for renewable energy sources

Groningen, Rijksuniversiteit

Note: This page contains sample records for the topic "high-efficiency organic solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Fuel Cell/Turbine Ultra High Efficiency Power System  

DOE Green Energy (OSTI)

FuelCell Energy, INC. (FCE) is currently involved in the design of ultra high efficiency power plants under a cooperative agreement (DE-FC26-00NT40) managed by the National Energy Technology Laboratory (NETL) as part of the DOE's Vision 21 program. Under this project, FCE is developing a fuel cell/turbine hybrid system that integrates the atmospheric pressure Direct FuelCell{reg_sign} (DFC{reg_sign}) with an unfired Brayton cycle utilizing indirect heat recovery from the power plant. Features of the DFC/T{trademark} system include: high efficiency, minimal emissions, simplicity in design, direct reforming internal to the fuel cell, no pressurization of the fuel cell, independent operating pressure of the fuel cell and turbine, and potential cost competitiveness with existing combined cycle power plants at much smaller sizes. Objectives of the Vision 21 Program include developing power plants that will generate electricity with net efficiencies approaching 75 percent (with natural gas), while producing sulfur and nitrogen oxide emissions of less than 0.01 lb/million BTU. These goals are significant improvements over conventional power plants, which are 35-60 percent efficient and produce emissions of 0.07 to 0.3 lb/million BTU of sulfur and nitrogen oxides. The nitrogen oxide and sulfur emissions from the DFC/T system are anticipated to be better than the Vision 21 goals due to the non-combustion features of the DFC/T power plant. The expected high efficiency of the DFC/T will also result in a 40-50 percent reduction in carbon dioxide emissions compared to conventional power plants. To date, the R&D efforts have resulted in significant progress including proof-of-concept tests of a sub-scale power plant built around a state-of-the-art DFC stack integrated with a modified Capstone Model 330 Microturbine. The objectives of this effort are to investigate the integration aspects of the fuel cell and turbine and to obtain design information and operational data that will be utilized in the design of a 40-MW high efficiency Vision 21 power plant. Additionally, these tests are providing the valuable insight for DFC/Turbine power plant potential for load following, increased reliability, and enhanced operability.

Hossein, Ghezel-Ayagh

2001-11-06T23:59:59.000Z

262

High-efficiency multidetector system for tumor scanning  

SciTech Connect

A high-efficiency detector system developed especially for medical imaging has three specially cut Ge(Li) coaxial detectors (total volume 249 cm$sup 3$). At 122 keV, the peak efficiency is 93 percent of that of a 7.6 x 7.6 cm NaI (Tl) detector. Degradation of the paralleled energy resolution is avoided and resolution is improved by 35 percent over that of conventional output-summing techniques by gating the detector outputs. In effect this multiplexes them to a single line output. (auth)

Kirby, J.A.; Phelps, P.L.; Armantrout, G.A.; Sawyer, D.; Beck, R.N.

1975-11-18T23:59:59.000Z

263

Biomimetic Dye Molecules for Solar Cells  

NLE Websites -- All DOE Office Websites (Extended Search)

Biomimetic Dye Molecules for Solar Cells Print Biomimetic Dye Molecules for Solar Cells Print Pressing energy problems provide opportunities for solid-state physicists and chemists to solve a major challenge: solar cell adoption. Though solar cells can use energy directly from the Sun to produce electricity that can be converted efficiently into other kinds of energy, they are currently too costly to compete with traditional (polluting) energy sources. The most cost-effective solar cells are not high-end, high-efficiency single-crystal devices, but rather low-end cells based on organic molecules or conducting polymers. Vital information for making organic solar cells more competitive for widespread implementation was obtained using near-edge x-ray absorption fine structure (NEXAFS) spectroscopy performed at ALS Beamline 8.0.1. The relevant energy levels of biomimetic dye molecules were mapped out systematically by determining their unoccupied molecular orbitals and their orientation. Organic molecules in dye-sensitized solar cells exhibit great potential to increase the efficiency and reduce the cost of photovoltaic power generation by allowing a wide variety of chemical modifications and combinations with inorganic nanocrystals.

264

Biomimetic Dye Molecules for Solar Cells  

NLE Websites -- All DOE Office Websites (Extended Search)

Biomimetic Dye Molecules for Solar Cells Print Biomimetic Dye Molecules for Solar Cells Print Pressing energy problems provide opportunities for solid-state physicists and chemists to solve a major challenge: solar cell adoption. Though solar cells can use energy directly from the Sun to produce electricity that can be converted efficiently into other kinds of energy, they are currently too costly to compete with traditional (polluting) energy sources. The most cost-effective solar cells are not high-end, high-efficiency single-crystal devices, but rather low-end cells based on organic molecules or conducting polymers. Vital information for making organic solar cells more competitive for widespread implementation was obtained using near-edge x-ray absorption fine structure (NEXAFS) spectroscopy performed at ALS Beamline 8.0.1. The relevant energy levels of biomimetic dye molecules were mapped out systematically by determining their unoccupied molecular orbitals and their orientation. Organic molecules in dye-sensitized solar cells exhibit great potential to increase the efficiency and reduce the cost of photovoltaic power generation by allowing a wide variety of chemical modifications and combinations with inorganic nanocrystals.

265

Biomimetic Dye Molecules for Solar Cells  

NLE Websites -- All DOE Office Websites (Extended Search)

Biomimetic Dye Molecules for Solar Cells Print Biomimetic Dye Molecules for Solar Cells Print Pressing energy problems provide opportunities for solid-state physicists and chemists to solve a major challenge: solar cell adoption. Though solar cells can use energy directly from the Sun to produce electricity that can be converted efficiently into other kinds of energy, they are currently too costly to compete with traditional (polluting) energy sources. The most cost-effective solar cells are not high-end, high-efficiency single-crystal devices, but rather low-end cells based on organic molecules or conducting polymers. Vital information for making organic solar cells more competitive for widespread implementation was obtained using near-edge x-ray absorption fine structure (NEXAFS) spectroscopy performed at ALS Beamline 8.0.1. The relevant energy levels of biomimetic dye molecules were mapped out systematically by determining their unoccupied molecular orbitals and their orientation. Organic molecules in dye-sensitized solar cells exhibit great potential to increase the efficiency and reduce the cost of photovoltaic power generation by allowing a wide variety of chemical modifications and combinations with inorganic nanocrystals.

266

Biomimetic Dye Molecules for Solar Cells  

NLE Websites -- All DOE Office Websites (Extended Search)

Biomimetic Dye Molecules for Solar Cells Print Biomimetic Dye Molecules for Solar Cells Print Pressing energy problems provide opportunities for solid-state physicists and chemists to solve a major challenge: solar cell adoption. Though solar cells can use energy directly from the Sun to produce electricity that can be converted efficiently into other kinds of energy, they are currently too costly to compete with traditional (polluting) energy sources. The most cost-effective solar cells are not high-end, high-efficiency single-crystal devices, but rather low-end cells based on organic molecules or conducting polymers. Vital information for making organic solar cells more competitive for widespread implementation was obtained using near-edge x-ray absorption fine structure (NEXAFS) spectroscopy performed at ALS Beamline 8.0.1. The relevant energy levels of biomimetic dye molecules were mapped out systematically by determining their unoccupied molecular orbitals and their orientation. Organic molecules in dye-sensitized solar cells exhibit great potential to increase the efficiency and reduce the cost of photovoltaic power generation by allowing a wide variety of chemical modifications and combinations with inorganic nanocrystals.

267

Biomimetic Dye Molecules for Solar Cells  

NLE Websites -- All DOE Office Websites (Extended Search)

Biomimetic Dye Molecules for Solar Cells Print Biomimetic Dye Molecules for Solar Cells Print Pressing energy problems provide opportunities for solid-state physicists and chemists to solve a major challenge: solar cell adoption. Though solar cells can use energy directly from the Sun to produce electricity that can be converted efficiently into other kinds of energy, they are currently too costly to compete with traditional (polluting) energy sources. The most cost-effective solar cells are not high-end, high-efficiency single-crystal devices, but rather low-end cells based on organic molecules or conducting polymers. Vital information for making organic solar cells more competitive for widespread implementation was obtained using near-edge x-ray absorption fine structure (NEXAFS) spectroscopy performed at ALS Beamline 8.0.1. The relevant energy levels of biomimetic dye molecules were mapped out systematically by determining their unoccupied molecular orbitals and their orientation. Organic molecules in dye-sensitized solar cells exhibit great potential to increase the efficiency and reduce the cost of photovoltaic power generation by allowing a wide variety of chemical modifications and combinations with inorganic nanocrystals.

268

Biomimetic Dye Molecules for Solar Cells  

NLE Websites -- All DOE Office Websites (Extended Search)

Biomimetic Dye Molecules for Solar Cells Print Biomimetic Dye Molecules for Solar Cells Print Pressing energy problems provide opportunities for solid-state physicists and chemists to solve a major challenge: solar cell adoption. Though solar cells can use energy directly from the Sun to produce electricity that can be converted efficiently into other kinds of energy, they are currently too costly to compete with traditional (polluting) energy sources. The most cost-effective solar cells are not high-end, high-efficiency single-crystal devices, but rather low-end cells based on organic molecules or conducting polymers. Vital information for making organic solar cells more competitive for widespread implementation was obtained using near-edge x-ray absorption fine structure (NEXAFS) spectroscopy performed at ALS Beamline 8.0.1. The relevant energy levels of biomimetic dye molecules were mapped out systematically by determining their unoccupied molecular orbitals and their orientation. Organic molecules in dye-sensitized solar cells exhibit great potential to increase the efficiency and reduce the cost of photovoltaic power generation by allowing a wide variety of chemical modifications and combinations with inorganic nanocrystals.

269

High Efficiency LED Lamp for Solid-State Lighting  

SciTech Connect

This report contains a summary of technical achievements during a three-year project to demonstrate high efficiency, solid-state lamps based on gallium nitride/silicon carbide light-emitting diodes. Novel chip designs and fabrication processes are described for a new type of nitride light-emitting diode with the potential for very high efficiency. This work resulted in the demonstration of blue light-emitting diodes in the one watt class that achieved up to 495 mW of light output at 350 mA drive current, corresponding to quantum and wall plug efficiencies of 51% and 45%, respectively. When combined with a phosphor in Cree's 7090 XLamp package, these advanced blue-emitting devices resulted in white light-emitting diodes whose efficacy exceeded 85 lumens per watt. In addition, up to 1040 lumens at greater than 85 lumens per watt was achieved by combining multiple devices to make a compact white lamp module with high optical efficiency.

James Ibbetson

2006-12-31T23:59:59.000Z

270

New III-V cell design approaches for very high efficiency  

DOE Green Energy (OSTI)

This report describes to examine new solar cell desip approaches for achieving very high conversion efficiencies. The program consists of two elements. The first centers on exploring new thin-film approaches specifically designed for M-III semiconductors. Substantial efficiency gains may be possible by employing light trapping techniques to confine the incident photons, as well as the photons emitted by radiative recombination. The thin-film approach is a promising route for achieving substantial performance improvements in the already high-efficiency, single-junction, III-V cell. The second element of the research involves exploring desip approaches for achieving high conversion efficiencies without requiring extremely high-quality material. This work has applications to multiple-junction cells, for which the selection of a component cell often involves a compromise between optimum band pp and optimum material quality. It could also be a benefit manufacturing environment by making the cell's efficiency less dependent on materialquality.

Lundstrom, M.S.; Melloch, M.R.; Lush, G.B.; Patkar, M.P.; Young, M.P. (Purdue Univ., Lafayette, IN (United States))

1993-04-01T23:59:59.000Z

271

SunShot Initiative: High-Efficiency Receivers for Supercritical...  

NLE Websites -- All DOE Office Websites (Extended Search)

cycle is also being explored. Innovation State-of-the-art solar receivers rely on air or molten salt as the working fluid. However, air has low thermal transfer properties and...

272

AUTOMATED SOLAR FLARE STATISTICS IN SOFT X-RAYS OVER 37 YEARS OF GOES OBSERVATIONS: THE INVARIANCE OF SELF-ORGANIZED CRITICALITY DURING THREE SOLAR CYCLES  

SciTech Connect

We analyzed the soft X-ray light curves from the Geostationary Operational Environmental Satellites over the last 37 years (1975-2011) and measured with an automated flare detection algorithm over 300,000 solar flare events (amounting to Almost-Equal-To 5 times higher sensitivity than the NOAA flare catalog). We find a power-law slope of {alpha}{sub F} = 1.98 {+-} 0.11 for the (background-subtracted) soft X-ray peak fluxes that is invariant through three solar cycles and agrees with the theoretical prediction {alpha}{sub F} = 2.0 of the fractal-diffusive self-organized criticality (FD-SOC) model. For the soft X-ray flare rise times, we find a power-law slope of {alpha}{sub T} = 2.02 {+-} 0.04 during solar cycle minima years, which is also consistent with the prediction {alpha}{sub T} = 2.0 of the FD-SOC model. During solar cycle maxima years, the power-law slope is steeper in the range of {alpha}{sub T} Almost-Equal-To 2.0-5.0, which can be modeled by a solar-cycle-dependent flare pile-up bias effect. These results corroborate the FD-SOC model, which predicts a power-law slope of {alpha}{sub E} = 1.5 for flare energies and thus rules out significant nanoflare heating. While the FD-SOC model predicts the probability distribution functions of spatio-temporal scaling laws of nonlinear energy dissipation processes, additional physical models are needed to derive the scaling laws between the geometric SOC parameters and the observed emissivity in different wavelength regimes, as we derive here for soft X-ray emission. The FD-SOC model also yields statistical probabilities for solar flare forecasting.

Aschwanden, Markus J.; Freeland, Samuel L., E-mail: aschwanden@lmsal.com [Lockheed Martin Advanced Technology Center, Solar and Astrophysics Laboratory, Org. ADBS, Building 252, 3251 Hanover Street, Palo Alto, CA 94304 (United States)

2012-08-01T23:59:59.000Z

273

System Effects of High Efficiency Filters in Homes  

NLE Websites -- All DOE Office Websites (Extended Search)

System Effects of High Efficiency Filters in Homes System Effects of High Efficiency Filters in Homes Title System Effects of High Efficiency Filters in Homes Publication Type Conference Paper LBNL Report Number LBNL-6144E Year of Publication 2013 Authors Walker, Iain S., Darryl J. Dickerhoff, David Faulkner, and William J. N. Turner Conference Name ASHRAE Annual Conference Date Published 03/2013 Abstract Occupant concern about indoor air quality (IAQ) issues has led to the increased use of more effective air filters in residential heating and cooling systems. A drawback of improved filtration is that better filters tend to have more flow resistance. This can lead to lower system airflows that reduce heat exchanger efficiency, increase duct pressure that leads to increased air leakage for ducts and, in some case s, increased blower power consumption. There is currently little knowledge on the magnitude of these effects. In this study, the performance of ten central forced air systems was monitored for a year. The systems used either a Permanent Split Capacitor (PSC) or a Brushless Permanent Magnet (BPM) blower. Each system was operated with a range of filter efficiencies ranging from MERV 6 (the lowest currently permitted in ASHRAE Standard 62.2) up to MERV 16. Measurements were recorded every ten seconds for blower power, filter pressure drop, supply and return plenum pressures together with plenum and indoor temperatures. These detailed continuous measurements allowed observation of filter loading effects as well as the initial change in system performance when filters were swapped. The results of the field measurements were used in simulations to examine more general system performance effects for a wider range of climates. The field tests showed that system static pressures were highly influenced by filter selection, filter loading rates varied more from house to house than by MERV rating and overall were quite low in many of the homes. PSC motors showed reduced power and airflow as the filters loaded, but BPM motors attempted to maintain a constant airflow and increased their power to do so. The combined field test and simulation results from this study indicate that for MERV 10-13 filters the effects on energy use are small (5%) and usability. In systems using low MERV filters that are already close to blower performance limits the addition of a MERV 16 filter pushed the blowers to their performance limits.

274

Desalination of seawater using a high-efficiency jet ejector  

E-Print Network (OSTI)

The ability to produce potable water economically is the primary focus of seawater desalination research. There are numerous methods to desalinate water, including reverse osmosis, multi-stage flash distillation, and multi-effect evaporation. These methods cost more than potable water produced from natural resources; hence an attempt is made in this research project to produce potable water using a modified high-efficiency jet ejector in vapor-compression distillation. The greater efficiency of the jet ejector is achieved by properly mixing propelled and motive streams. From experiments conducted using air, the pressure rise across the jet ejector is better in case of one or two mixing vanes and the highest back pressure (pinch valve closed 83.33%). At other pinch valve closings, the air velocity through the jet ejector was high, so the extra surface area from the mixing vanes caused excessive friction and lowered the efficiency.

Vishwanathappa, Manohar D.

2003-05-01T23:59:59.000Z

275

Implications of high efficiency power cycles for fusion reactor design  

SciTech Connect

The implications of the High Efficiency Power Cycle for fusion reactors are examined. The proposed cycle converts most all of the high grade CTR heat input to electricity. A low grade thermal input (T approximately 100$sup 0$C) is also required, and this can be supplied at low cost geothermal energy at many locations in the U. S. Approximately 3 KW of low grade heat is required per KW of electrical output. The thermodynamics and process features of the proposed cycle are discussed. Its advantages for CTR's are that low Q machines (e.g. driven Tokamaks, mirrors) can operate with a high (approximately 80 percent) conversion of CTR fusion energy to electricity, where with conventional power cycles no plant output could be achieved with such low Q operation. (auth)

Powell, J.R.; Usher, J.; Salzano, F.J.

1975-01-01T23:59:59.000Z

276

HIGH EFFICIENCY FOSSIL POWER PLANT (HEFPP) CONCEPTUALIZATION PROGRAM  

SciTech Connect

This study confirms the feasibility of a natural gas fueled, 20 MW M-C Power integrated pressurized molten carbonate fuel cell combined in a topping cycle with a gas turbine generator plant. The high efficiency fossil power plant (HEFPP) concept has a 70% efficiency on a LHV basis. The study confirms the HEFPP has a cost advantage on a cost of electricity basis over the gas turbine based combined cycle plants in the 20 MW size range. The study also identifies the areas of further development required for the fuel cell, gas turbine generator, cathode blower, inverter, and power module vessel. The HEFPP concept offers an environmentally friendly power plant with minuscule emission levels when compared with the combined cycle power plant.

J.L. Justice

1999-03-25T23:59:59.000Z

277

Thin Film Packaging Solutions for High Efficiency OLED Lighting Products  

Science Conference Proceedings (OSTI)

The objective of the 'Thin Film Packaging Solutions for High Efficiency OLED Lighting Products' project is to demonstrate thin film packaging solutions based on SiC hermetic coatings that, when applied to glass and plastic substrates, support OLED lighting devices by providing longer life with greater efficiency at lower cost than is currently available. Phase I Objective: Demonstrate thin film encapsulated working phosphorescent OLED devices on optical glass with lifetime of 1,000 hour life, CRI greater than 75, and 15 lm/W. Phase II Objective: Demonstrate thin film encapsulated working phosphorescent OLED devices on plastic or glass composite with 25 lm/W, 5,000 hours life, and CRI greater than 80. Phase III Objective: Demonstrate 2 x 2 ft{sup 2} thin film encapsulated working phosphorescent OLED with 40 lm/W, 10,000 hour life, and CRI greater than 85. This report details the efforts of Phase III (Budget Period Three), a fourteen month collaborative effort that focused on optimization of high-efficiency phosphorescent OLED devices and thin-film encapsulation of said devices. The report further details the conclusions and recommendations of the project team that have foundation in all three budget periods for the program. During the conduct of the Thin Film Packaging Solutions for High Efficiency OLED Lighting Products program, including budget period three, the project team completed and delivered the following achievements: (1) a three-year marketing effort that characterized the near-term and longer-term OLED market, identified customer and consumer lighting needs, and suggested prototype product concepts and niche OLED applications lighting that will give rise to broader market acceptance as a source for wide area illumination and energy conservation; (2) a thin film encapsulation technology with a lifetime of nearly 15,000 hours, tested by calcium coupons, while stored at 16 C and 40% relative humidity ('RH'). This encapsulation technology was characterized as having less than 10% change in transmission during the 15,000 hour test period; (3) demonstrated thin film encapsulation of a phosphorescent OLED device with 1,500 hours of lifetime at 60 C and 80% RH; (4) demonstrated that a thin film laminate encapsulation, in addition to the direct thin film deposition process, of a polymer OLED device was another feasible packaging strategy for OLED lighting. The thin film laminate strategy was developed to mitigate defects, demonstrate roll-to-roll process capability for high volume throughput (reduce costs) and to support a potential commercial pathway that is less dependent upon integrated manufacturing since the laminate could be sold as a rolled good; (5) demonstrated that low cost 'blue' glass substrates could be coated with a siloxane barrier layer for planarization and ion-protection and used in the fabrication of a polymer OLED lighting device. This study further demonstrated that the substrate cost has potential for huge cost reductions from the white borosilicate glass substrate currently used by the OLED lighting industry; (6) delivered four-square feet of white phosphorescent OLED technology, including novel high efficiency devices with 82 CRI, greater than 50 lm/W efficiency, and more than 1,000 hours lifetime in a product concept model shelf; (7) presented and or published more than twenty internal studies (for private use), three external presentations (OLED workshop-for public use), and five technology-related external presentations (industry conferences-for public use); and (8) issued five patent applications, which are in various maturity stages at time of publication. Delivery of thin film encapsulated white phosphorescent OLED lighting technology remains a challenging technical achievement, and it seems that commercial availability of thin, bright, white OLED light that meets market requirements will continue to require research and development effort. However, there will be glass encapsulated white OLED lighting products commercialized in niche markets during the 2008 calendar year. This commercializ

None

2008-06-30T23:59:59.000Z

278

High efficiency carbonate fuel cell/turbine hybrid power cycle  

Science Conference Proceedings (OSTI)

The hybrid power cycle studies were conducted to identify a high efficiency, economically competitive system. A hybrid power cycle which generates power at an LHV efficiency > 70% was identified that includes an atmospheric pressure direct carbonate fuel cell, a gas turbine, and a steam cycle. In this cycle, natural gas fuel is mixed with recycled fuel cell anode exhaust, providing water for reforming fuel. The mixed gas then flows to a direct carbonate fuel cell which generates about 70% of the power. The portion of the anode exhaust which is not recycled is burned and heat transferred through a heat exchanger (HX) to the compressed air from a gas turbine. The heated compressed air is then heated further in the gas turbine burner and expands through the turbine generating 15% of the power. Half the exhaust from the turbine provides air for the anode exhaust burner. All of the turbine exhaust eventually flows through the fuel cell cathodes providing the O2 and CO2 needed in the electrochemical reaction. Exhaust from the cathodes flows to a steam system (heat recovery steam generator, staged steam turbine generating 15% of the cycle power). Simulation of a 200 MW plant with a hybrid power cycle had an LHV efficiency of 72.6%. Power output and efficiency are insensitive to ambient temperature, compared to a gas turbine combined cycle; NOx emissions are 75% lower. Estimated cost of electricity for 200 MW is 46 mills/kWh, which is competitive with combined cycle where fuel cost is > $5.8/MMBTU. Key requirement is HX; in the 200 MW plant studies, a HX operating at 1094 C using high temperature HX technology currently under development by METC for coal gassifiers was assumed. A study of a near term (20 MW) high efficiency direct carbonate fuel cell/turbine hybrid power cycle has also been completed.

Steinfeld, G.; Maru, H.C. [Energy Research Corp., Danbury, CT (United States); Sanderson, R.A. [Sanderson (Robert) and Associates, Wethersfield, CT (United States)

1996-07-01T23:59:59.000Z

279

Organic photochemical storage of solar energy. Progress report, March 1, 1978-January 31, 1979  

DOE Green Energy (OSTI)

Photosensitization mechanisms for driving energy storing reactions of readily available organic compounds have been studied. Aromatic sensitizers were used as complexing agents for a series of non-conjugated dienes which are capable of valence isomerization. Diene exciplexes, shown to be stabilized by electron donor-acceptor interaction, led to photoisomers with high chemical and quantum efficiency in two of the cases studied. For other systems, sensitizer-diene photoaddition reactions were observed. Exciplex isomerization of quadricyclanes and hexamethyldewarbenzene was studied. Factors determining the efficiency of rearrangement of excited complexes were examined including the role of exciplex excitation energy in controlling the novel adiabatic exciplex isomerization of hexamethyldewarbenzene. With triplet photosensitizers visible light (to 520 nm) was used to bring about an energy storing valence isomerization of a diester derivative of norbornadiene. High quantum yields (0.6) were measured at the longest wavelengths yet utilized for this type of isomerization. The quantum efficiency for isomerization using a very low energy triplet sensitizer was significantly enhanced at slightly elevated temperatures, suggesting that thermal energy (in amounts present in solar collector media) can be an aid in driving energy storing photo-reactions.

Jones, G. II

1979-02-01T23:59:59.000Z

280

High efficiency thin-film multiple-gap photovoltaic device  

SciTech Connect

A photovoltaic device includes at least two solar cells made from Group IV elements or their alloys in the amorphous state mounted on a substrate. The outermost or first cell has a larger bandgap than the second cell. Various techniques are utilized to improve the efficiency of the device.

Dalal, Vikram L. (Newark, DE)

1983-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "high-efficiency organic solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Analysis of applications of solar technology for the treatment of chlorinated organic waste  

DOE Green Energy (OSTI)

Recent work has demonstrated that concentrated solar energy can destroy many hazardous chemical that are of national concern including dioxins, polychlorinated biphenyls (PCBs), and chlorinated solvents. A detailed systems analysis was performed to determine the applicability of solar detoxification to the treatment of chlorinated solvents. This work determined the cost of destruction of trichlorethylene (TCE) a using conventional and a solar-based technology were compared for this application. This work provides a basis for choosing an application in which solar energy can be used to its fullest potential to solve a growing national problem. 9 refs., 8 figs.

Glatzmaier, G C

1990-11-01T23:59:59.000Z

282

Indium-Tin-Oxide-Based Transparent Conducting Layers for Highly Efficient Photovoltaic Devices  

Science Conference Proceedings (OSTI)

Additional hydrogen (H{sub 2}) annealing and subsequent electrochemical treatment are found to make tin-doped indium oxide (ITO)-based photoelectrodes suitable for highly efficient dye sensitized solar cells. The additional H{sub 2} annealing process recovered the electrical conductivity of the ITO film the same as its initial high conductivity, which enhanced the charge collecting property. Moreover, the employment of electrochemical oxidation of TiO{sub 2}/ITO photoelectrode improved the energy conversion efficiency of the ITO-based dye-sensitized solar cells (DSSC), higher than that of a conventional FTO-based DSSC. Electrochemical impedance analysis showed that the H2 annealing process reduced the internal resistance of the cell, i.e., the resistance of the ITO and the Schottky barrier at the TiO{sub 2}/ITO interface were reduced, and that the electrochemical treatment recovered the diodelike characteristics of the DSSC by retarding back electron transfer from the photoelectrode to the electrolyte. The present work demonstrates that thermally and electrochemically modified ITO-based photoelectrode is another alternative to the conventionally used FTO-based photoelectrode.

Lee, S.; Noh, J. H.; Bae, S. T.; Cho, I. S.; Kim, J. Y.; Shin, H.; Lee, J. K.; Jung, H. S.; Hong, K. S.

2009-01-01T23:59:59.000Z

283

HIGH EFFICIENCY GENERATION OF HYDROGEN FUELS USING NUCLEAR POWER  

DOE Green Energy (OSTI)

OAK B202 HIGH EFFICIENCY GENERATION OF HYDROGEN FUELS USING NUCLEAR POWER. Combustion of fossil fuels, used to power transportation, generate electricity, heat homes and fuel industry provides 86% of the world's energy. Drawbacks to fossil fuel utilization include limited supply, pollution, and carbon dioxide emissions. Carbon dioxide emissions, thought to be responsible for global warming, are now the subject of international treaties. Together, these drawbacks argue for the replacement of fossil fuels with a less-polluting potentially renewable primary energy such as nuclear energy. Conventional nuclear plants readily generate electric power but fossil fuels are firmly entrenched in the transportation sector. Hydrogen is an environmentally attractive transportation fuel that has the potential to displace fossil fuels. Hydrogen will be particularly advantageous when coupled with fuel cells. Fuel cells have higher efficiency than conventional battery/internal combustion engine combinations and do not produce nitrogen oxides during low-temperature operation. Contemporary hydrogen production is primarily based on fossil fuels and most specifically on natural gas. When hydrogen is produced using energy derived from fossil fuels, there is little or no environmental advantage. There is currently no large scale, cost-effective, environmentally attractive hydrogen production process available for commercialization, nor has such a process been identified. The objective of this work is to find an economically feasible process for the production of hydrogen, by nuclear means, using an advanced high-temperature nuclear reactor as the primary energy source. Hydrogen production by thermochemical water-splitting (Appendix A), a chemical process that accomplishes the decomposition of water into hydrogen and oxygen using only heat or, in the case of a hybrid thermochemical process, by a combination of heat and electrolysis, could meet these goals. Hydrogen produced from fossil fuels has trace contaminants (primarily carbon monoxide) that are detrimental to precious metal catalyzed fuel cells, as is now recognized by many of the world's largest automobile companies. Thermochemical hydrogen will not contain carbon monoxide as an impurity at any level. Electrolysis, the alternative process for producing hydrogen using nuclear energy, suffers from thermodynamic inefficiencies in both the production of electricity and in electrolytic parts of the process. The efficiency of electrolysis (electricity to hydrogen) is currently about 80%. Electric power generation efficiency would have to exceed 65% (thermal to electrical) for the combined efficiency to exceed the 52% (thermal to hydrogen) calculated for one thermochemical cycle. Thermochemical water-splitting cycles have been studied, at various levels of effort, for the past 35 years. They were extensively studied in the late 70s and early 80s but have received little attention in the past 10 years, particularly in the U.S. While there is no question about the technical feasibility and the potential for high efficiency, cycles with proven low cost and high efficiency have yet to be developed commercially. Over 100 cycles have been proposed, but substantial research has been executed on only a few. This report describes work accomplished during a three-year project whose objective is to ''define an economically feasible concept for production of hydrogen, by nuclear means, using an advanced high temperature nuclear reactor as the energy source.'' The emphasis of the first phase was to evaluate thermochemical processes which offer the potential for efficient, cost-effective, large-scale production of hydrogen from water in which the primary energy input is high temperature heat from an advanced nuclear reactor and to select one (or, at most three) for further detailed consideration. During Phase 1, an exhaustive literature search was performed to locate all cycles previously proposed. The cycles located were screened using objective criteria to determine which could benefit, in terms of efficien

BROWN,LC; BESENBRUCH,GE; LENTSCH,RD; SCHULTZ,KR; FUNK,JF; PICKARD,PS; MARSHALL,AC; SHOWALTER,SK

2003-06-01T23:59:59.000Z

284

HIGH EFFICIENCY GENERATION OF HYDROGEN FUELS USING NUCLEAR POWER  

SciTech Connect

OAK B202 HIGH EFFICIENCY GENERATION OF HYDROGEN FUELS USING NUCLEAR POWER. Combustion of fossil fuels, used to power transportation, generate electricity, heat homes and fuel industry provides 86% of the world's energy. Drawbacks to fossil fuel utilization include limited supply, pollution, and carbon dioxide emissions. Carbon dioxide emissions, thought to be responsible for global warming, are now the subject of international treaties. Together, these drawbacks argue for the replacement of fossil fuels with a less-polluting potentially renewable primary energy such as nuclear energy. Conventional nuclear plants readily generate electric power but fossil fuels are firmly entrenched in the transportation sector. Hydrogen is an environmentally attractive transportation fuel that has the potential to displace fossil fuels. Hydrogen will be particularly advantageous when coupled with fuel cells. Fuel cells have higher efficiency than conventional battery/internal combustion engine combinations and do not produce nitrogen oxides during low-temperature operation. Contemporary hydrogen production is primarily based on fossil fuels and most specifically on natural gas. When hydrogen is produced using energy derived from fossil fuels, there is little or no environmental advantage. There is currently no large scale, cost-effective, environmentally attractive hydrogen production process available for commercialization, nor has such a process been identified. The objective of this work is to find an economically feasible process for the production of hydrogen, by nuclear means, using an advanced high-temperature nuclear reactor as the primary energy source. Hydrogen production by thermochemical water-splitting (Appendix A), a chemical process that accomplishes the decomposition of water into hydrogen and oxygen using only heat or, in the case of a hybrid thermochemical process, by a combination of heat and electrolysis, could meet these goals. Hydrogen produced from fossil fuels has trace contaminants (primarily carbon monoxide) that are detrimental to precious metal catalyzed fuel cells, as is now recognized by many of the world's largest automobile companies. Thermochemical hydrogen will not contain carbon monoxide as an impurity at any level. Electrolysis, the alternative process for producing hydrogen using nuclear energy, suffers from thermodynamic inefficiencies in both the production of electricity and in electrolytic parts of the process. The efficiency of electrolysis (electricity to hydrogen) is currently about 80%. Electric power generation efficiency would have to exceed 65% (thermal to electrical) for the combined efficiency to exceed the 52% (thermal to hydrogen) calculated for one thermochemical cycle. Thermochemical water-splitting cycles have been studied, at various levels of effort, for the past 35 years. They were extensively studied in the late 70s and early 80s but have received little attention in the past 10 years, particularly in the U.S. While there is no question about the technical feasibility and the potential for high efficiency, cycles with proven low cost and high efficiency have yet to be developed commercially. Over 100 cycles have been proposed, but substantial research has been executed on only a few. This report describes work accomplished during a three-year project whose objective is to ''define an economically feasible concept for production of hydrogen, by nuclear means, using an advanced high temperature nuclear reactor as the energy source.'' The emphasis of the first phase was to evaluate thermochemical processes which offer the potential for efficient, cost-effective, large-scale production of hydrogen from water in which the primary energy input is high temperature heat from an advanced nuclear reactor and to select one (or, at most three) for further detailed consideration. During Phase 1, an exhaustive literature search was performed to locate all cycles previously proposed. The cycles located were screened using objective criteria to determine which could

BROWN,LC; BESENBRUCH,GE; LENTSCH,RD; SCHULTZ,KR; FUNK,JF; PICKARD,PS; MARSHALL,AC; SHOWALTER,SK

2003-06-01T23:59:59.000Z

285

Organic Based Nanocomposite Solar Cells: Cooperative Research and Development Final Report, CRADA Number CRD-04-145  

DOE Green Energy (OSTI)

This CRADA will focus on the development of organic-based solar cells. Key interfacial issues in these cells will be investigated. In this rapidly emerging technology, it is increasingly clear that cell architecture will need to be at the nanoscale and the interfacial issues between organic elements (small molecule and polymer), transparent conducting oxides, and contact metallizations are critical. Thus this work will focus on the development of high surface area and nanostructured nanocarpets of inorganic oxides, the development of appropriate surface binding/acceptor molecules for the inorganic/organic interface, and the development of next-generation organic materials. Work will be performed in all three areas jointly at NREL and Konarka (with their partner in the third area of the University of Delaware). Results should be more rapid progress toward cheap large-area photovoltaic cells.

Olson, D.

2013-01-01T23:59:59.000Z

286

HIGH-EFFICIENCY NITRIDE-BASED SOLID-STATE LIGHTING  

SciTech Connect

In this second annual report we summarize the progress in the second-year period of Department of Energy contract DE-FC26-01NT41203, entitled ''High- Efficiency Nitride-Based Solid-State Lighting''. The two teams, from the University of California at Santa Barbara (Principle Investigator: Dr. Shuji Nakamura) and Rensselaer Polytechnic Institute (led by Dr. N. Narendran), are pursuing the goals of this contract from thin film growth, characterization, and packaging standpoints. The UCSB team has recently made significant progress in the development of light-emitting diodes (LEDs) with AlGaN active regions emitting in the ultraviolet (UV), resonant-cavity LEDs (RCLEDs), as well as lateral epitaxial overgrowth (LEO) techniques to obtain large-area non-polar GaN films with low average dislocation density. The Rensselaer team has benchmarked the performance of commercially available LED systems and has also conducted efforts to develop an optimized RCLED packaging scheme, including development of advanced epoxy encapsulant chemistries.

Paul T. Fini; Shuji Nakamura

2003-10-30T23:59:59.000Z

287

Highly Efficient Small Form Factor LED Retrofit Lamp  

SciTech Connect

This report summarizes work to develop a high efficiency LED-based MR16 lamp downlight at OSRAM SYLVANIA under US Department of Energy contract DE-EE0000611. A new multichip LED package, electronic driver, and reflector optic were developed for these lamps. At steady-state, the lamp luminous flux was 409 lumens (lm), luminous efficacy of 87 lumens per watt (LPW), CRI (Ra) of 87, and R9 of 85 at a correlated color temperature (CCT) of 3285K. The LED alone achieved 120 lumens per watt efficacy and 600 lumen flux output at 25 C. The driver had 90% electrical conversion efficiency while maintaining excellent power quality with power factor >0.90 at a power of only 5 watts. Compared to similar existing MR16 lamps using LED sources, these lamps had much higher efficacy and color quality. The objective of this work was to demonstrate a LED-based MR16 retrofit lamp for replacement of 35W halogen MR16 lamps having (1) luminous flux of 500 lumens, (2) luminous efficacy of 100 lumens per watt, (3) beam angle less than 40{sup o} and center beam candlepower of at least 1000 candelas, and (4) excellent color quality.

Steven Allen; Fred Palmer; Ming Li

2011-09-11T23:59:59.000Z

288

Research on stable, high-efficiency amorphous silicon multijunction modules  

DOE Green Energy (OSTI)

This report describes research to improve the understanding of amorphous silicon alloys and other relevant non-semiconductor materials for use in high-efficiency, large-area multijunction modules. The research produced an average subcell initial efficiency of 8.8% over a 1-ft{sup 2} area using same-band-gap, dual-junction cells deposited over a ZnO/AlSi back reflector. An initial efficiency of 9.6% was achieved using a ZnO/Ag back reflector over smaller substrates. A sputtering machine will be built to deposit a ZnO/Ag back reflector over a 1-ft{sup 2} area so that a higher efficiency can also be obtained on larger substrates. Calculations have been performed to optimize the grid pattern, bus bars, and cell interconnects on modules. With our present state of technology, we expect a difference of about 6% between the aperture-area and active-area efficiencies of modules. Preliminary experiments show a difference of about 8%. We can now predict the performance of single-junction cells after long-term light exposure at 50{degree}C by exposing cells to short-term intense light at different temperatures. We find that single-junction cells deposited on a ZnO/Ag back reflector show the highest stabilized efficiency when the thickness of the intrinsic layers is about 2000 {angstrom}. 8 refs.

Guha, S. (United Solar Systems Corp., Troy, MI (United States))

1991-12-01T23:59:59.000Z

289

Analysis of highly-efficient electric residential HPWHs  

DOE Green Energy (OSTI)

A scoping level analysis was conducted to identify electric HPWH concepts that have the potential to achieve or exceed 30% source energy savings compared to a gas tankless water heater (GTWH) representative of the type represented in version 0.9.5.2 beta of the BEopt software developed by the National Renewable Energy Laboratory. The analysis was limited to evaluation of options to improve the energy efficiency of electric HPWH product designs currently on the market in the US. The report first defines the baseline GTWH system and determines its efficiency (source-energy-based adjusted or derated EF of ~0.71). High efficiency components (compressors, pumps, fans, heat exchangers, etc.) were identified and applied to current US HPWH products and analyzed to determine the viability of reaching the target EF. The target site-based energy factor (EF) required for an electric HPWH necessary to provide 30% source energy savings compared to the GTWH baseline unit is then determined to be ~3.19.

Baxter, Van D [ORNL; Murphy, Richard W [ORNL; Rice, C Keith [ORNL; Shen, Bo [ORNL; Gao, Zhiming [ORNL

2011-09-01T23:59:59.000Z

290

In-Plant Testing of High-Efficiency Hydraulic Separators  

SciTech Connect

Hydraulic separators are commonly used for particle size classification and gravity concentration of minerals and coal. Unfortunately, the efficiency of these processes can be quite low due to poor equipment design and variations in feed consistency. To help alleviate these problems, an industry-driven R&D program has been undertaken to develop a new generation of hydraulic separators that are more efficient and less costly to operate and maintain. These units, which are commercially called the CrossFlow separator and HydroFloat separator, have the potential to improve performance (separation efficiency and throughput) and reduce operating costs (power consumption, water and reagent usage). In Phase I of this project, laboratory and pilot-scale test units were evaluated at various industrial sites in both the coal and mineral industries. Based on promising results obtained from Phase I, full-scale prototypes were purchased and installed by a major U.S. phosphate producer and a large eastern U.S. coal company. The test data obtained from these sites demonstrate that significant performance improvements can be realized through the application of these high-efficiency separators.

G. H. Luttrell; R. Q. Honaker; R. C. Bratton; T. C. Westerfield; J. N. Kohmuench

2006-06-30T23:59:59.000Z

291

IN-PLANT TESTING OF HIGH-EFFICIENCY HYDRAULIC SEPARATORS  

SciTech Connect

Hydraulic separators are commonly used for particle size classification and gravity concentration of minerals and coal. Unfortunately, the efficiency of these processes can be quite low due to poor equipment design and variations in feed consistency. To help alleviate these problems, an industry-driven R&D program has been undertaken to develop a new generation of hydraulic separators that are more efficient and less costly to operate and maintain. These units, which are commercially called the CrossFlow separator and HydroFloat separator, have the potential to improve performance (separation efficiency and throughput) and reduce operating costs (power consumption, water and reagent usage). In Phase I of this project, laboratory and pilot-scale test units were evaluated at various industrial sites in both the coal and mineral industries. Based on promising results obtained from Phase I, full-scale prototypes were purchased and installed by a major U.S. phosphate producer and a large eastern U.S. coal company. The test data obtained from these sites demonstrate that significant performance improvements can be realized through the application of these high-efficiency separators.

G.H. Luttrell; R.Q. Honaker; R.C. Bratton; T.C. Westerfield; J.N. Kohmuench

2006-05-22T23:59:59.000Z

292

Novel Materials for HIgh Efficiency White Phosphorescent OLED  

SciTech Connect

Our program was a materials intensive one, based on preparing new materials for phosphorescent based white organic LEDs (WOLEDs). Each of the principal projects are summarized.

Mark Thompson

2008-03-31T23:59:59.000Z

293

Feasibility of High-Efficiency Photovoltaics Breakthrough Research  

Science Conference Proceedings (OSTI)

For the past three decades, solar photovoltaic (PV) installed capacity has rapidly grown and its price has steadily declined. If these historic trends of technology and market development can be maintained, it is likely that PV resources will contribute about 10% of new U.S. capacity within 25 years. However, PV technologies may still require subsidies to compete with other energy sources. This study investigated the potential and means for significant cost reductions to enable more widespread adoption o...

2005-10-18T23:59:59.000Z

294

Advances in solar assisted drying systems for agricultural produce  

Science Conference Proceedings (OSTI)

The technical directions in the development of solar assisted drying systems system for agricultural produce are compact collector design, high efficiency, integrated storage, and long-life drying system. Air based solar collectors are not the only available ... Keywords: V-groove solar collector, double-pass solar collector, photovoltaic thermal collectors, solar assisted chemical heat pump system, solar dehumidification system

Kamaruzzaman Sopian; Mohd Yusof Sulaiman; Mohd Yusof Othman; Sohif Mat; Muhamad Yahya; Mohamad A. Alghoul; Baharudin Ali; Lim Chin Haw; Mohd Hafidz Ruslan; Azami Zaharim

2009-02-01T23:59:59.000Z

295

Program on Technology Innovation: High Efficiency Photovoltaic Research at the Institute of Research and Development on Photovoltaic Energy (IRDEP), 2012  

Science Conference Proceedings (OSTI)

This report describes the advances of the High-Efficiency Photovoltaic (HEPV) Program during 2012. The report focuses on technical advances in the hot-carrier solar-cell program that address compounds with improved photovoltaic (PV) energy-conversion potential. The basic idea of hot-carrier devices is to use a combination of materials and device structures that can tap the thermal power co-generated with the usual PV power harvested in conventional devices. A part of this thermal power, all lost in ...

2013-11-04T23:59:59.000Z

296

Design of high efficiency blowers for future aerosol applications  

E-Print Network (OSTI)

High efficiency air blowers to meet future portable aerosol sampling applications were designed, fabricated, and evaluated. A Centrifugal blower was designed to achieve a flow rate of 100 L/min (1.67 x 10^-3 m^3/s) and a pressure rise of WC " 4 (1000 PA). Commercial computational fluid dynamics (CFD) software, FLUENT 6.1.22, was used extensively throughout the entire design cycle. The machine, Reynolds number (Re) , was around 10^5 suggesting a turbulent flow field. Renormalization Group (RNG) �ºâ���µ turbulent model was used for FLUENT simulations. An existing design was scaled down to meet the design needs. Characteristic curves showing static pressure rise as a function of flow rate through the impeller were generated using FLUENT and these were validated through experiments. Experimentally measured efficiency (�·EXP) for the base-design was around 10%. This was attributed to the low efficiency of the D.C. motor used. CFD simulations, using the �ºâ���µ turbulent model and standard wall function approach, over-predicted the pressure rise values and the percentage error was large. Enhanced wall function under-predicted the pressure rise but gave better agreement (less than 6% error) with experimental results. CFD predicted a blower scaled 70% in planar direction (XZ) and 28% in axial direction (Y) and running at 19200 rpm (70xz_28y@19.2k) as the most appropriate choice. The pressure rise is 1021 Pa at the design flow rate of 100 L/min. FLUENT predicts an efficiency value based on static head (�·FLU) as 53.3%. Efficiency value based on measured static pressure rise value and the electrical energy input to the motor (�·EXP) is 27.4%. This is almost a 2X improvement over the value that one gets with the hand held vacuum system blower.

Chadha, Raman

2005-12-01T23:59:59.000Z

297

Electrical heating of soils using high efficiency electrode patterns and power phases  

DOE Patents (OSTI)

Powerline-frequency electrical (joule) heating of soils using a high efficiency electrode configuration and power phase arrangement. The electrode configuration consists of several heating or current injection electrodes around the periphery of a volume of soil to be heated, all electrodes being connected to one phase of a multi-phase or a single-phase power system, and a return or extraction electrode or electrodes located inside the volume to be heated being connected to the remaining phases of the multi-phase power system or to the neutral side of the single-phase power source. This electrode configuration and power phase arrangement can be utilized anywhere where powerline frequency soil heating is applicable and thus has many potential uses including removal of volatile organic compounds such as gasoline and tricholorethylene (TCE) from contaminated areas.

Buettner, Harley M. (Livermore, CA)

1999-01-01T23:59:59.000Z

298

New III-V cell design approaches for very high efficiency  

DOE Green Energy (OSTI)

This report describes progress during the first year of a three-year project. The objective of the research is to examine new design approaches for achieving very high conversion efficiencies. The program is divided into two areas. The first centers on exploring new thin-film approaches specifically designed for III-V semiconductors. The second area centers on exploring design approaches for achieving high conversion efficiencies without requiring extremely high quality material. Research activities consisted of an experimental study of minority carrier recombination in n-type, metal-organic chemical vapor deposition (MOCVD)-deposited GaAs, an assessment of the minority carrier lifetimes in n-GaAs grown by molecular beam epitaxy, and developing a high-efficiency cell fabrication process.

Lundstrom, M.S.; Melloch, M.R.; Lush, G.B.; O'Bradovich, G.J.; Young, M.P. (Purdue Univ., Lafayette, IN (United States))

1993-01-01T23:59:59.000Z

299

NREL Measures IMM Solar Cell Performance for CPV (Fact Sheet...  

NLE Websites -- All DOE Office Websites (Extended Search)

New measurement capability supports the development of high-efficiency solar cells for concentrating photovoltaic (CPV) application. NREL scientists recently completed a set of...

300

Liquid Metal, a Heat Transport Fluid for High Temperature Solar ...  

Science Conference Proceedings (OSTI)

The need for high efficiency and direct heat conversion into hydrogen, process heat and energy storage pushes the temperature for solar concentrator systems.

Note: This page contains sample records for the topic "high-efficiency organic solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Increasing the efficiency of organic solar cells by photonic and electrostatic-field enhancements  

SciTech Connect

Organic photovoltaic (OPV) technology is an attractive solar-electric conversion paradigm due to the promise of low cost roll-to-roll production and amenability to flexible substrates. Power conversion efficiency (PCE) exceeding 7% has recently been achieved. OPV cells suffer from low charge carrier mobilities of polymers, leading to recombination losses, higher series resistances and lower fill-factors. Thus, it is imperative to develop fabrication methodologies that can enable efficient optical absorption in films thinner than optical absorption length. Active layers conformally deposited on light-trapping, microscale textured, grating-type surfaces is one possible approach to achieve this objective. In this study, 40% theoretical increase in photonic absorption over flat OPVs is shown for devices with textured geometry by the simulation results. For verifying this theoretical result and improving the efficiency of OPVs by light trapping, OPVs were fabricated on grating-type textured substrates possessing t pitch and -coat PV active-layer on these textured substrates led to over filling of the valleys and shunts at the crest, which severely affected the performance of the resultant PV devices. Thus, it is established that although the optical design is important for OPV performance but the potential of light trapping can only be effectively tapped if the textures are amenable for realizing a conformal active layer. It is discovered that if the height of the underlying topographical features is reduced to sub-micron regime (e.g. 300 nm) and the pitch is increased to more than a micron (e.g. 2 ?m), the textured surface becomes amenable to coating a conformal PV active-layer. The resultant PV cells showed 100% increase in average light absorption near the band edge due to trapping of higher wavelength photons, and 20% improvement in power conversion efficiency as compared with the flat PV cell. Another factor that severely limits the performance of OPVs is recombination of charge carriers. Thus it becomes imperative to understand the effect of processing conditions such as spin coating speed and drying rate on defect density and hence induced carrier recombination mechanism. In this study, It is shown that slow growth (longer drying time) of the active-layer leads to reduction of sub-bandgap traps by an order of magnitude as compared to fast grown active-layer. By coupling the experimental results with simulations, it is demonstrated that at one sun condition, slow grown device has bimolecular recombination as the major loss mechanism while in the fast grown device with high trap density, the trap assisted recombination dominates. It has been estimated that non-radiative recombination accounts nearly 50% of efficiency loss in modern OPVs. Generally, an external bias (electric field) is required to collect all the photogenerated charges and thus prevent their recombination. The motivation is to induce additional electric field in otherwise low mobility conjugated polymer based active layer by incorporating ferroelectric dipoles. This is expected to facilitate singlet exciton dissociation in polymer matrix and impede charge transfer exciton (CTE) recombination at polymer:fullerene interface. For the first time, it is shown that the addition of ferroelectric dipoles to modern bulk heterojunction (BHJ) can significantly improve exciton dissociation, resulting in a ~50% enhancement of overall solar cell efficiency. The devices also exhibit the unique ferroelectric-photovoltaic effect with polarization-controlled power conversion efficiency.

Nalwa, Kanwar

2012-11-03T23:59:59.000Z

302

for ITO-free, PEDOT:PSS-free bulk-heterojunction organic solar cells  

Science Conference Proceedings (OSTI)

The power conversion efficiency of the OSC with the ZAM electrode is lower than ... solar cells on ITO which has 3.3% efficiency, due to lower transmittance after ... Morphology Evolution to Restoration of Plasma-Induced Damage in Porous ...

303

High Efficiency, Ultra-Low Emission, Integrated Process Heater System  

Science Conference Proceedings (OSTI)

The team of TIAX LLC, ExxonMobil Research and Engineering Company, and Callidus Technologies, LLC conducted a six-year program to develop an ultra-low emission process heater burner and an advanced high efficiency heater design. This project addresses the critical need of process heater operators for reliable, economical emission reduction technologies to comply with stringent emission regulations, and for heater design alternatives that reduce process heater energy requirements without significant cost increase. The key project targets were NOx emissions of 10 ppm (@ 3% O2), and a heater thermal efficiency of 95 percent. The ultra low NOx burner was developed through a series of pilot-scale and field tests combined with computational fluid dynamic modeling to arrive at simultaneous low emissions and suitable flame shape and stability. Pilot scale tests were run at TIAX, at the 2 MMBtu/hr scale, and at Callidus at 8 MMBtu/hr. The full scale burner was installed on a 14 burner atmospheric pipestill furnace at an ExxonMobil refinery. A variety of burner configurations, gas tips and flame stabilizers were tested to determine the lowest emissions with acceptable flame shape and stability. The resulting NOx emissions were 22 ppm on average. Starting in 2001, Callidus commercialized the original ultra low NOx burner and made subsequent design improvements in a series of commercial burners evolving from the original concept and/or development. Emissions in the field with the ultra low-NOx burner over a broad spectrum of heater applications have varied from 5 ppm to 30 ppm depending on heater geometry, heater service, fuel and firing capacity. To date, 1550 of the original burners, and 2500 of subsequent generation burners have been sold by Callidus. The advanced heater design was developed by parametric evaluations of a variety of furnace and combustion air preheater configurations and technologies for enhancing convective and radiative heat transfer. The design evolution relied heavily on computational fluid dynamic predictions of design alternatives. The final design features modular separate radiant cells, each with one and two-side fired vertical tubes. The convection section configuration is vertical tube banks enclosed in the radiant channels. Commercial modular plate air preheaters are used. The predicted performance for the integrated advanced heater and Callidus burner is 95 percent efficiency with 9 ppm NOx emissions firing natural gas, and 12 ppm firing refinery gas. The total erected cost is less than a conventional heater with combustion air preheat.

Mason, Howard; Boral, Anindya; Chhotray, San; Martin, Matthew

2006-06-19T23:59:59.000Z

304

High Efficiency, Low Emissions Homogeneous Charge Compression Ignition (HCCI) Engines  

SciTech Connect

This is the final report of the High Efficiency Clean Combustion (HECC) Research Program for the U.S. Department of Energy. Work under this co-funded program began in August 2005 and finished in July 2010. The objective of this program was to develop and demonstrate a low emission, high thermal efficiency engine system that met 2010 EPA heavy-duty on-highway truck emissions requirements (0.2g/bhp-hr NOx, 0.14g/bhp-hr HC and 0.01g/bhp-hr PM) with a thermal efficiency of 46%. To achieve this goal, development of diesel homogenous charge compression ignition (HCCI) combustion was the chosen approach. This report summarizes the development of diesel HCCI combustion and associated enabling technologies that occurred during the HECC program between August 2005 and July 2010. This program showed that although diesel HCCI with conventional US diesel fuel was not a feasible means to achieve the program objectives, the HCCI load range could be increased with a higher volatility, lower cetane number fuel, such as gasoline, if the combustion rate could be moderated to avoid excessive cylinder pressure rise rates. Given the potential efficiency and emissions benefits, continued research of combustion with low cetane number fuels and the effects of fuel distillation are recommended. The operation of diesel HCCI was only feasible at part-load due to a limited fuel injection window. A 4% fuel consumption benefit versus conventional, low-temperature combustion was realized over the achievable operating range. Several enabling technologies were developed under this program that also benefited non-HCCI combustion. The development of a 300MPa fuel injector enabled the development of extended lifted flame combustion. A design methodology for minimizing the heat transfer to jacket water, known as precision cooling, will benefit conventional combustion engines, as well as HCCI engines. An advanced combustion control system based on cylinder pressure measurements was developed. A Well-to-wheels analysis of the energy flows in a mobile vehicle system and a 2nd Law thermodynamic analysis of the engine system were also completed under this program.

None

2011-01-31T23:59:59.000Z

305

Low Temperature Combustion Demonstrator for High Efficiency Clean Combustion  

SciTech Connect

The project which extended from November 2005 to May of 2010 demonstrated the application of Low Temperature Combustion (LTC) with engine out NOx levels of 0.2 g/bhp-hr throughout the program target load of 12.6bar BMEP. The project showed that the range of loads could be extended to 16.5bar BMEP, therefore matching the reference lug line of the base 2007 MY Navistar 6.4L V8 engine. Results showed that the application of LTC provided a dramatic improvement over engine out emissions when compared to the base engine. Furthermore LTC improved thermal efficiency by over 5% from the base production engine when using the steady state 13 mode composite test as a benchmark. The key enablers included improvements in the air, fuel injection, and cooling systems made in Phases I and II. The outcome was the product of a careful integration of each component under an intelligent control system. The engine hardware provided the conditions to support LTC and the controller provided the necessary robustness for a stable combustion. Phase III provided a detailed account on the injection strategy used to meet the high load requirements. During this phase, the control strategy was implemented in a production automotive grade ECU to perform cycle-by-cycle combustion feedback on each of the engine cylinders. The control interacted on a cycle base with the injection system and with the Turbo-EGR systems according to their respective time constants. The result was a unique system that could, first, help optimize the combustion system and maintain high efficiency, and secondly, extend the steady state results to the transient mode of operation. The engine was upgraded in Phase IV with a Variable Valve Actuation system and a hybrid EGR loop. The impact of the more versatile EGR loop did not provide significant advantages, however the application of VVA proved to be an enabler to further extend the operation of LTC and gain considerable benefits in fuel economy and soot reduction. Finally, the transient demonstration was performed in Phase IV. The project demonstrated the achievement of meeting US10 emissions without NOx aftertreatment. The successful execution of the project has served to highlight the effectiveness of closely matched combustion predictive tools to engine testing. It has further served to highlight the importance of key technologies and future areas of research and development. In this regard, recommendations are made towards further improvements in the areas of engine hardware, fuel injection systems, controls and fuels.

Ojeda, William de

2010-07-31T23:59:59.000Z

306

Heterojunction solar cell  

DOE Patents (OSTI)

A high-efficiency single heterojunction solar cell is described wherein a thin emitter layer (preferably Ga[sub 0.52]In[sub 0.48]P) forms a heterojunction with a GaAs absorber layer. The conversion efficiency of the solar cell is at least 25.7%. The solar cell preferably includes a passivating layer between the substrate and the absorber layer. An anti-reflection coating is preferably disposed over the emitter layer. 1 fig.

Olson, J.M.

1994-08-30T23:59:59.000Z

307

Heterojunction solar cell  

DOE Patents (OSTI)

A high-efficiency single heterojunction solar cell wherein a thin emitter layer (preferably Ga.sub.0.52 In.sub.0.48 P) forms a heterojunction with a GaAs absorber layer. The conversion effiency of the solar cell is at least 25.7%. The solar cell preferably includes a passivating layer between the substrate and the absorber layer. An anti-reflection coating is preferably disposed over the emitter layer.

Olson, Jerry M. (Lakewood, CO)

1994-01-01T23:59:59.000Z

308

Development of high efficiency collector plates. Final report  

DOE Green Energy (OSTI)

Composite metal technology was used to manufacture intermetallic compound (IC) absorption surfaces and to combine them integrally with composite metal tube-in-sheet collector plates. Five material systems in which Al was one component metal and Fe, Cr, or Ni and their alloy was the other pair, were evaluated. All intermetallic compounds had high solar absorptance ..cap alpha.. approx. = 0.9. The AlNi was most promising and ..cap alpha.. > or = 0.95 and epsilon approx. = 0.3 were obtained over a broad range of compounding conditions. After eight months exposure in a flat plate collector enclosure the characteristic properties of AlNi surfaces remained virtually unchanged. Only LCS/Cu composite metal tube-in-sheet collector plates could be manufactured successfully. The technical difficulties associated with integrating the intermetallic compound and tube-in-sheet technologies make the manufacturing of composite metal collector plates at the time being economically unfeasible.

Santala, T.; Sabol, R.

1976-02-01T23:59:59.000Z

309

A high-efficiency indirect lighting system utilizing the solar 1000 sulfur lamp  

E-Print Network (OSTI)

and Renewable Energy, Office of Building Technology, State andand Renewable Energy, Office of Building Technology, State and

Siminovitch, Michael; Gould, C.; Page, E.

1997-01-01T23:59:59.000Z

310

High-Efficiency Receivers for Supercritical Carbon Dioxide Cycles, Concentrating Solar Power (Fact Sheet)  

Science Conference Proceedings (OSTI)

Brayton Energy is one of the 2012 SunShot CSP R&D awardees for their advanced receivers. This fact sheet explains the motivation, description, and impact of the project.

Not Available

2012-09-01T23:59:59.000Z

311

High efficiency low cost thin film silicon solar cell design and method for making  

DOE Patents (OSTI)

A semiconductor device having a substrate, a conductive intermediate layer deposited onto said substrate, wherein the intermediate layer serves as a back electrode, an optical reflector, and an interface for impurity gettering, and a semiconductor layer deposited onto said intermediate layer, wherein the semiconductor layer has a grain size at least as large as the layer thickness, and preferably about ten times the layer thickness. The device is formed by depositing a metal layer on a substrate, depositing a semiconductive material on the metal-coated substrate to produce a composite structure, and then optically processing the composite structure by illuminating it with infrared electromagnetic radiation according to a unique time-energy profile that first produces pits in the backside surface of the semiconductor material, then produces a thin, highly reflective, low resistivity alloy layer over the entire area of the interface between the semiconductor material and the metal layer, and finally produces a grain-enhanced semiconductor layer. The time-energy profile includes increasing the energy to a first energy level to initiate pit formation and create the desired pit size and density, then ramping up to a second energy level in which the entire device is heated to produce an interfacial melt, and finally reducing the energy to a third energy level and holding for a period of time to allow enhancement in the grain size of the semiconductor layer.

Sopori, Bhushan L. (Denver, CO)

1999-01-01T23:59:59.000Z

312

High efficiency, low cost, thin film silicon solar cell design and method for making  

DOE Patents (OSTI)

A semiconductor device having a substrate, a conductive intermediate layer deposited onto said substrate, wherein the intermediate layer serves as a back electrode, an optical reflector, and an interface for impurity gettering, and a semiconductor layer deposited onto said intermediate layer, wherein the semiconductor layer has a grain size at least as large as the layer thickness, and preferably about ten times the layer thickness. The device is formed by depositing a metal layer on a substrate, depositing a semiconductive material on the metal-coated substrate to produce a composite structure, and then optically processing the composite structure by illuminating it with infrared electromagnetic radiation according to a unique time-energy profile that first produces pits in the backside surface of the semiconductor material, then produces a thin, highly reflective, low resistivity alloy layer over the entire area of the interface between the semiconductor material and the metal layer, and finally produces a grain-enhanced semiconductor layer. The time-energy profile includes increasing the energy to a first energy level to initiate pit formation and create the desired pit size and density, then ramping up to a second energy level in which the entire device is heated to produce an interfacial melt, and finally reducing the energy to a third energy level and holding for a period of time to allow enhancement in the grain size of the semiconductor layer.

Sopori, Bhushan L. (Denver, CO)

2001-01-01T23:59:59.000Z

313

High efficiency low cost thin film silicon solar cell design and method for making  

DOE Patents (OSTI)

A semiconductor device is described having a substrate, a conductive intermediate layer deposited onto said substrate, wherein the intermediate layer serves as a back electrode, an optical reflector, and an interface for impurity gettering, and a semiconductor layer deposited onto said intermediate layer, wherein the semiconductor layer has a grain size at least as large as the layer thickness, and preferably about ten times the layer thickness. The device is formed by depositing a metal layer on a substrate, depositing a semiconductive material on the metal-coated substrate to produce a composite structure, and then optically processing the composite structure by illuminating it with infrared electromagnetic radiation according to a unique time-energy profile that first produces pits in the backside surface of the semiconductor material, then produces a thin, highly reflective, low resistivity alloy layer over the entire area of the interface between the semiconductor material and the metal layer, and finally produces a grain-enhanced semiconductor layer. The time-energy profile includes increasing the energy to a first energy level to initiate pit formation and create the desired pit size and density, then ramping up to a second energy level in which the entire device is heated to produce an interfacial melt, and finally reducing the energy to a third energy level and holding for a period of time to allow enhancement in the grain size of the semiconductor layer. 9 figs.

Sopori, B.L.

1999-04-27T23:59:59.000Z

314

Development of high efficiency cascade solar cells. Quarterly technical progress report No. 3  

DOE Green Energy (OSTI)

Progress is reported in the following areas: AlGaAsSb/GaAsSb materials development, GaInP materials development via VPE, GaAlAs/GaAs cell development, and OM/CVD studies. Spectral response, V-I characteristics, and electron microprobe analysis results are presented. (WHK)

Not Available

1980-03-31T23:59:59.000Z

315

A high-efficiency indirect lighting system utilizing the solar 1000 sulfur lamp  

SciTech Connect

High-lumen light sources represent unique challenges and opportunities for the design of practical and efficient interior lighting systems. High-output sources require a means of large-scale distribution and avoidance of high-luminance glare while providing efficient delivery. An indirect lighting system has been developed for use with a 1,000 Watt sulfur lamp that efficiently utilizes the high-output source to provide quality interior lighting. This paper briefly describes the design and initial testing of this new system.

Siminovitch, M.; Gould, C.; Page, E.

1997-06-01T23:59:59.000Z

316

Current-matched, high-efficiency, multi-junction monolithic solar cells  

DOE Patents (OSTI)

In this invention, the efficiency of a two-junction (cascade) tandem photovoltaic device is improved by adjusting (decreasing) the top cell thickness to achieve current matching. An example of the invention was fabricated out of Ga{sub 0.52}In{sub 0.48}P and GaAs. Additional lattice-matched systems to which the invention pertains include Al{sub x}Ga{sub l-x}/GaAs (x=0.3 {minus} 0.4), GaAs/Ge and Ga{sub y}In{sub 1-y}P/Ga{sub y+0.5}In{sub 0.5-{sub Y}} As (O

Olson, J.M.; Kurtz, S.R.

1991-02-11T23:59:59.000Z

317

Hierarchical ZnO Nano-tree Growth for High Efficiency Solar Cell  

Science Conference Proceedings (OSTI)

Investigation on Co-combustion Kinetics of Anthracite Coal and Biomass Char ... Three-Dimensional Nickel Nanoparticle/Graphene Aerogel for Direct Ethanol ...

318

Fabrication of heterojunction solar cells by improved tin oxide deposition on insulating layer  

DOE Patents (OSTI)

Highly efficient tin oxide-silicon heterojunction solar cells are prepared by heating a silicon substrate, having an insulating layer thereon, to provide a substrate temperature in the range of about 300.degree. C. to about 400.degree. C. and thereafter spraying the so-heated substrate with a solution of tin tetrachloride in a organic ester boiling below about 250.degree. C. Preferably the insulating layer is naturally grown silicon oxide layer.

Feng, Tom (Morris Plains, NJ); Ghosh, Amal K. (New Providence, NJ)

1980-01-01T23:59:59.000Z

319

High-Efficiency Nitride-Based Solid-State Lighting  

SciTech Connect

In this final technical progress report we summarize research accomplished during Department of Energy contract DE-FC26-01NT41203, entitled ''High-Efficiency Nitride-Based Solid-State Lighting''. Two teams, from the University of California at Santa Barbara (Principle Investigator: Dr. Shuji Nakamura) and the Lighting Research Center at Rensselaer Polytechnic Institute (led by Dr. N. Narendran), pursued the goals of this contract from thin film growth, characterization, and packaging/luminaire design standpoints. The UCSB team initially pursued the development of blue gallium nitride (GaN)-based vertical-cavity surface-emitting lasers, as well as ultraviolet GaN-based light emitting diodes (LEDs). In Year 2, the emphasis shifted to resonant-cavity light emitting diodes, also known as micro-cavity LEDs when extremely thin device cavities are fabricated. These devices have very directional emission and higher light extraction efficiency than conventional LEDs. Via the optimization of thin-film growth and refinement of device processing, we decreased the total cavity thickness to less than 1 {micro}m, such that micro-cavity effects were clearly observed and a light extraction efficiency of over 10% was reached. We also began the development of photonic crystals for increased light extraction, in particular for so-called ''guided modes'' which would otherwise propagate laterally in the device and be re-absorbed. Finally, we pursued the growth of smooth, high-quality nonpolar a-plane and m-plane GaN films, as well as blue light emitting diodes on these novel films. Initial nonpolar LEDs showed the expected behavior of negligible peak wavelength shift with increasing drive current. M-plane LEDs in particular show promise, as unpackaged devices had unsaturated optical output power of {approx} 3 mW at 200 mA drive current. The LRC's tasks were aimed at developing the subcomponents necessary for packaging UCSB's light emitting diodes, and packaging them to produce a white light fixture. During the third and final year of the project, the LRC team investigated alternate packaging methods for the white LED device to achieve at least 25 percent more luminous efficacy than traditional white LEDs; conducted optical ray-tracing analyses and human factors studies to determine the best form factor for the white light source under development, in terms of high luminous efficacy and greater acceptance by subjects; and developed a new die encapsulant using silicone-epoxy resins that showed less yellowing and slower degradation. At the conclusion of this project, the LRC demonstrated a new packaging method, called scattered photon extraction (SPE), that produced an average luminous flux and corresponding average efficacy of 90.7 lm and 36.3 lm/W, respectively, compared with 56.5 lm and 22.6 lm/W for a similar commercial white LED package. At low currents, the SPE package emitted white light with an efficacy of over 80 lm/W and had chromaticity values very close to the blackbody locus. The SPE package showed an overall improvement of 61% for this particular comparison, exceeding the LRC's third-year goal of 25% improvement.

Paul T. Fini; Shuji Nakamura

2005-07-30T23:59:59.000Z

320

EVALUATION OF A LOW FRICTION - HIGH EFFICIENCY ROLLER BEARING ENGINE  

SciTech Connect

This Low Friction (High Efficiency Roller Bearing) Engine (LFE) report presents the work done by The Timken Company to conduct a technology demonstration of the benefits of replacing hydrodynamic bearings with roller bearings in the crankshaft and camshaft assemblies of an internal combustion engine for the purpose of collecting data sufficient to prove merit. The engines in the present study have been more extensively converted to roller bearings than any previous studies (40 needle roller bearings per engine) to gain understanding of the full potential of application of bearing technology. The project plan called for comparative testing of a production vehicle which was already respected for having demonstrated low engine friction levels with a rollerized version of that engine. Testing was to include industry standard tests for friction, emissions and fuel efficiency conducted on instrumented dynamometers. Additional tests for fuel efficiency, cold start resistance and other measures of performance were to be made in the actual vehicle. Comparative measurements of noise, vibration and harshness (NVH), were planned, although any work to mitigate the suspected higher NVH level in the rollerized engine was beyond the scope of this project. Timken selected the Toyota Avalon with a 3.5L V-6 engine as the test vehicle. In an attempt to minimize cost and fabrication time, a ‘made-from’ approach was proposed in which as many parts as possible would be used or modified from production parts to create the rollerized engine. Timken commissioned its test partner, FEV Engine Technology, to do a feasibility study in which they confirmed that using such an approach was possible to meet the required dimensional restrictions and tolerances. In designing the roller bearing systems for the crank and cam trains, Timken utilized as many production engine parts as possible. The crankshafts were produced from production line forgings, which use Timken steel, modified with special machining and heat treatment. Timken designed and manufactured all of the roller bearing related components such as the thrust bearing package. The production connecting rods and camshafts could not be used for the roller bearing engine, so new ones were produced according to the team’s designs using Timken steel. The remaining miscellaneous components were designed and procured by FEV. Timken prepared a display version of the crankshaft portion of the production engine without connecting rods which could be driven by a motor through a cogged-belt and electrically actuated clutch arrangement. A modified version was also made in which the engine was outfitted with roller bearings on the main bearing positions. Preliminary tests showed that the rollerized engine was running with 1/3 less friction than the standard display engine. Additional friction testing and noise characterization was cut short because of shipping damage to the rollerized engine display and because of other project priorities. The team did successfully demonstrate the ability to package roller bearings satisfactorily in numerous locations in a typical automotive engine. The scope of this project did not include durability demonstration and that subject would have to be addressed in any follow-on work. In the actual test phase, the rollerized engine did show significantly less friction in motored dynamometer tests compared to its production equivalent. The 5-10% improvement measured in this study was about half that seen in other studies. However, the fired test results did not show a reduction in friction which did not match prior experience or expectations. Subsequent teardown and inspection of the rollerized engine revealed potential sources of excessive friction in the experimental application. These features would be eliminated in a design not based on modification of production parts. The team is confident (based on experience) that friction reduction would be realized with proper modifications.

Kolarik, Robert V. II; Shattuck, Charles W.; Copper, Anthony P.

2009-06-30T23:59:59.000Z

Note: This page contains sample records for the topic "high-efficiency organic solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

High-efficiency photovoltaics based on semiconductor nanostructures  

SciTech Connect

The objective of this project was to exploit a variety of semiconductor nanostructures, specifically semiconductor quantum wells, quantum dots, and nanowires, to achieve high power conversion efficiency in photovoltaic devices. In a thin-film device geometry, the objectives were to design, fabricate, and characterize quantum-well and quantum-dot solar cells in which scattering from metallic and/or dielectric nanostructures was employed to direct incident photons into lateral, optically confined paths within a thin (~1-3um or less) device structure. Fundamental issues concerning nonequilibrium carrier escape from quantum-confined structures, removal of thin-film devices from an epitaxial growth substrate, and coherent light trapping in thin-film photovoltaic devices were investigated. In a nanowire device geometry, the initial objectives were to engineer vertical nanowire arrays to optimize optical confinement within the nanowires, and to extend this approach to core-shell heterostructures to achieve broadspectrum absorption while maintaining high opencircuit voltages. Subsequent work extended this approach to include fabrication of nanowire photovoltaic structures on low-cost substrates.

Yu, Paul K.L. [University of California, San Diego; Yu, Edward T. [University of Texas at Austin; Wang, Deli [University of California, San Diego

2011-10-31T23:59:59.000Z

322

Towards an understanding of light activation processes in titanium oxide based inverted organic solar cells  

E-Print Network (OSTI)

, 233903 (2012) Thin-film encapsulation of inverted indium-tin-oxide-free polymer solar cells by atomic structures.2­5 In an inverted PSC, electrons are collected by the indium tin oxide (ITO) bottom electrode of increasing attention around the world for the last 20 years as a potential source of renewable energy. PSC

323

High-temperature photochemical destruction of toxic organic wastes using concentrated solar radiation  

DOE Green Energy (OSTI)

Application of concentrated solar energy has been proposed to be a viable waste disposal option. Specifically, this concept of solar induced high-temperature photochemistry is based on the synergistic contribution of concentrated infrared (IR) radiation, which acts as an intense heating source, and near ultraviolet and visible (UV-VIS) radiation, which can induce destructive photochemical processes. Some significant advances have been made in the theoretical framework of high-temperature photochemical processes (Section 2) and development of experimental techniques for their study (Section 3). Basic thermal/photolytic studies have addressed the effect of temperature on the photochemical destruction of pure compounds (Section 4). Detailed studies of the destruction of reaction by-products have been conducted on selected waste molecules (Section 5). Some very limited results are available on the destruction of mixtures (Section 6). Fundamental spectroscopic studies have been recently initiated (Section 7). The results to date have been used to conduct some relatively simple scale-up studies of the solar detoxification process. More recent work has focused on destruction of compounds that do not directly absorb solar radiation. Research efforts have focused on homogeneous as well as heterogeneous methods of initiating destructive reaction pathways (Section 9). Although many conclusions at this point must be considered tentative due to lack of basic research, a clearer picture of the overall process is emerging (Section 10). However, much research remains to be performed and most follow several veins, including photochemical, spectroscopic, combustion kinetic, and engineering scale-up (Section 11).

Dellinger, B.; Graham, J.L.; Berman, J.M.; Taylor, P.H. [Dayton Univ., OH (United States)

1994-05-01T23:59:59.000Z

324

Novel Morphology of Highly Efficient Two-phase Ferrite Cores for ...  

Science Conference Proceedings (OSTI)

This discovery may very well usher in a new chapter in high efficiency power cores for high frequency inductors, transformers, power supplies, converters, and

325

Alloy Design of 9% Cr Steel for High Efficiency Ultra-Supercritical ...  

Science Conference Proceedings (OSTI)

Presentation Title, Alloy Design of 9% Cr Steel for High Efficiency Ultra- Supercritical Power Plants. Author(s), Fujio Abe. On-Site Speaker (Planned), Fujio Abe.

326

Preliminary screening of thermal storage concepts for water/steam and organic fluid solar thermal receiver systems  

DOE Green Energy (OSTI)

A preliminary comparison of thermal storage concepts for solar thermal applications was done generically for large and small solar systems with sensible and latent heat and two-stage storage concepts. Concepts were ranked based on the cost of delivered energy. A +- 20% uncertainty in subsystem cost was included in the analysis. Water/steam and organic fluid collector/receivers were studied separately. For the water/steam concept, Barstow technology (100 MW/sub e/) was examined. A nitrite/nitrate salt with a low-cost solid medium was best for buffer storage; for diurnal storage, the two-stage draw salt/low-cost media and oil/rock concept was best. Phase change concepts require improvements on the concept analyzed to be attractive. For the organic fluid system, a Shenandoah total energy system was examined. The Syltherm trickle charge taconite concept was the most favorable and may be improved by replacing the taconite with a lower-cost oil-compatible medium. Salt concepts can be competitive with this system only if there is a low-cost solid medium that is compatible with the salt and the end use requires a large amount of storage. The phase change concept examined was found to be quite poor for this total energy application.

Copeland, R.J.; Karpuk, M.E.; Ullman, J.L.

1980-04-01T23:59:59.000Z

327

High-Efficiency Nitride-Base Photonic Crystal Light Sources  

DOE Green Energy (OSTI)

The research activities performed in the framework of this project represent a major breakthrough in the demonstration of Photonic Crystals (PhC) as a competitive technology for LEDs with high light extraction efficiency. The goals of the project were to explore the viable approaches to manufacturability of PhC LEDS through proven standard industrial processes, establish the limits of light extraction by various concepts of PhC LEDs, and determine the possible advantages of PhC LEDs over current and forthcoming LED extraction concepts. We have developed three very different geometries for PhC light extraction in LEDs. In addition, we have demonstrated reliable methods for their in-depth analysis allowing the extraction of important parameters such as light extraction efficiency, modal extraction length, directionality, internal and external quantum efficiency. The information gained allows better understanding of the physical processes and the effect of the design parameters on the light directionality and extraction efficiency. As a result, we produced LEDs with controllable emission directionality and a state of the art extraction efficiency that goes up to 94%. Those devices are based on embedded air-gap PhC - a novel technology concept developed in the framework of this project. They rely on a simple and planar fabrication process that is very interesting for industrial implementation due to its robustness and scalability. In fact, besides the additional patterning and regrowth steps, the process is identical as that for standard industrially used p-side-up LEDs. The final devices exhibit the same good electrical characteristics and high process yield as a series of test standard LEDs obtained in comparable conditions. Finally, the technology of embedded air-gap patterns (PhC) has significant potential in other related fields such as: increasing the optical mode interaction with the active region in semiconductor lasers; increasing the coupling of the incident light into the active region of solar cells; increasing the efficiency of the phosphorous light conversion in white light LEDs etc. In addition to the technology of embedded PhC LEDs, we demonstrate a technique for improvement of the light extraction and emission directionality for existing flip-chip microcavity (thin) LEDs by introducing PhC grating into the top n-contact. Although, the performances of these devices in terms of increase of the extraction efficiency are not significantly superior compared to those obtained by other techniques like surface roughening, the use of PhC offers some significant advantages such as improved and controllable emission directionality and a process that is directly applicable to any material system. The PhC microcavity LEDs have also potential for industrial implementation as the fabrication process has only minor differences to that already used for flip-chip thin LEDs. Finally, we have demonstrated that achieving good electrical properties and high fabrication yield for these devices is straightforward.

James Speck; Evelyn Hu; Claude Weisbuch; Yong-Seok Choi; Kelly McGroddy; Gregor Koblmuller; Elison Matioli; Elizabeth Rangel; Fabian Rol; Dobri Simeonov

2010-01-31T23:59:59.000Z

328

Program on Technology Innovation: Very High Efficiency Photovoltaics Research, 2009 Update  

Science Conference Proceedings (OSTI)

This is the second interim annual summary report on the collaborative activities of CNRS and EDF RD to advance the state of high-efficiency photovoltaics (PV). This activity is principally concerned with basic research to enhance longer-term prospects of very high efficiency PV, but it also includes possible nearer-term outcomes of improved conversion efficiency for existing technologies.

2010-02-19T23:59:59.000Z

329

Nanocrystal Solar Cells  

E-Print Network (OSTI)

Nov, 2005). Chapter 4 Hybrid solar cells with 3-dimensional5 All-inorganic nanocrystal solar cells 5.1 Introduction Inoperation of organic based solar cells and distinguish them

Gur, Ilan

2006-01-01T23:59:59.000Z

330

Highly-efficient noise-assisted energy transport in classical oscillator systems  

E-Print Network (OSTI)

Photosynthesis is a biological process that involves the highly-efficient transport of energy captured from the sun to a reaction center, where conversion into useful biochemical energy takes place. Even though one can always use a quantum perspective to describe any physical process, since everything follows the laws of Quantum Mechanics, is the use of quantum theory imperative to explain this high efficiency? Several theoretical studies suggest that the high efficiency can only be understood as a result of the interplay between the quantum coherent evolution of the photosynthetic system, and noise introduced by its surrounding environment. Notwithstanding, we show here that noise-assisted highly-efficient energy transport can be found as well in purely classical systems; therefore, we might conclude that high efficiency energy transfer in photosynthetic systems could also be anticipated by classical models, without the need to resorting to quantum effects. Strikingly, the wider scope of applicability of the...

León-Montiel, R de J

2013-01-01T23:59:59.000Z

331

Singlet exciton fission, a multi-exciton generation process, in organic semiconductor solar cells  

E-Print Network (OSTI)

Organic semiconductor photovoltaics hold the promise of cheap production and low manufacturing setup costs. The highest efficiency seen in research labs, ~10% today, is still too low for production. In this work we explore ...

Jadhav, Priyadarshani

2012-01-01T23:59:59.000Z

332

Transparent, near-infrared organic photovoltaic solar cells for window and energy-scavenging applications  

E-Print Network (OSTI)

We fabricate near-infrared absorbing organic photovoltaics that are highly transparent to visible light. By optimizing near-infrared optical-interference, we demonstrate power efficiencies of 1.3±0.1% with simultaneous ...

Lunt, Richard R.

333

Effect of Spatial Organization on Solar Radiative Transfer in Three-Dimensional Idealized Stratocumulus Cloud Fields  

Science Conference Proceedings (OSTI)

To relate the error associated with 1D radiative calculations to the geometrical scales of cloud organization and/or in-cloud optical inhomogeneities, a new idealized methodology, based on a Fourier statistical technique, has been developed. ...

F. Di Giuseppe; A. M. Tompkins

2003-08-01T23:59:59.000Z

334

GaNPAs Solar Cells Lattice-Matched To GaP: Preprint  

DOE Green Energy (OSTI)

This conference paper describes the III-V semiconductors grown on silicon substrates are very attractive for lower-cost, high-efficiency multijunction solar cells, but lattice-mismatched alloys that result in high dislocation densities have been unable to achieve satisfactory performance. GaNxP1-x-yAsy is a direct-gap III-V alloy that can be grown lattice-matched to Si when y= 4.7x - 0.1. We propose the use of lattice-matched GaNPAs on silicon for high-efficiency multijunction solar cells. We have grown GaNxP1-x-yAsy on GaP (with a similar lattice constant to silicon) by metal-organic chemical vapor phase epitaxy with direct band-gaps in the range of 1.5 to 2.0 eV. We demonstrate the performance of single-junction GaNxP1-x-yAsy solar cells grown on GaP substrates and discuss the prospects for the development of monolithic high-efficiency multijunction solar cells based on silicon substrates.

Geisz, J. F.; Friedman, D. J.; Kurtz, S.

2002-05-01T23:59:59.000Z

335

Green Systems Solar Hot Water  

E-Print Network (OSTI)

Green Systems Solar Hot Water Heating the Building Co-generation: Heat Recovery System: Solar Thermal Panels (Trex enclosure) Hot Water Storage Tank (TS-5; basement) Hot Water Heaters (HW-1,2; basement) Pre-heats water so water heaters don't need to use as much energy Gas-powered, high efficiency

Schladow, S. Geoffrey

336

Nanostructured Electrodes For Organic Bulk Heterojunction Solar Cells: Model Study Using Carbon Nanotube Dispersed Polythiophene-fullerene Blend Devices  

Science Conference Proceedings (OSTI)

We test the feasibility of using nanostructured electrodes in organic bulk heterojunction solar cells to improve their photovoltaic performance by enhancing their charge collection efficiency and thereby increasing the optimal active blend layer thickness. As a model system, small concentrations of single wall carbon nanotubes are added to blends of poly(3-hexylthiophene): [6,6]-phenyl-C{sub 61}-butyric acid methyl ester in order to create networks of efficient hole conduction pathways in the device active layer without affecting the light absorption. The nanotube addition leads to a 22% increase in the optimal blend layer thickness from 90 nm to 110 nm, enhancing the short circuit current density and photovoltaic device efficiency by as much as {approx}10%. The associated incident-photon-to-current conversion efficiency for the given thickness also increases by {approx}10% uniformly across the device optical absorption spectrum, corroborating the enhanced charge carrier collection by nanostructured electrodes.

Nam, C.Y.; Wu, Q.; Su, D.; Chiu, C.-y; Tremblay, N.J.; Nuckolls, C,; Black, C.T.

2011-09-19T23:59:59.000Z

337

Candidate chemical systems for air cooled solar powered, absorption air conditioner design. Part I. Organic absorbent systems  

DOE Green Energy (OSTI)

All the available experimental evidence suggests that the optimum ''organic'' absorbent/refrigerant combination would be a methane derivative with a single hydrogen atom with chlorine and fluorine atoms in the other sites, as refrigerant. This would be hydrogen bonded to an absorbent molecule containing the group =NC/sup -/O, with the substituent groups being such that no steric hindrance took place. Cycle analyses showed that the ratio of internal heat transfer to cooling would be large, probably impractically so in view of the high coefficient of performance needed for solar driven cooling and the additional handicap of heat rejection to the atmosphere. A more promising approach would be to reduce the internal heat transfer per unit of space cooling by selecting a refrigerant with a high latent heat of vaporization and selecting an absorbent with suitable properties.

Biermann, W.J.

338

Green Light-Emitting Diode Makes Highly Efficient White Light, The Spectrum of Clean Energy Innovation (Fact Sheet)  

NLE Websites -- All DOE Office Websites (Extended Search)

Spectrum of Spectrum of Clean Energy Innovation innovati n Green Light-Emitting Diode Makes Highly Efficient White Light Scientists at the National Renewable Energy Laboratory (NREL) have invented a deep green light-emitting diode (LED) that can lead to higher efficiency white light, which is of prime value in the indoor lighting world. LEDs are fundamentally solar cells operating in reverse-that is, when an electrical current is applied to a thin-film semiconductor, the result is the emission of light. These devices are a key technology for producing a new generation of efficient lighting, in which the amount of light generated far outweighs the amount of heat produced. But at the moment, LEDs that emit white light are produced using an inefficient process known as phosphor conversion. In this process, light from a blue- or ultraviolet-emitting LED energizes

339

Solar dish/engine systems  

DOE Green Energy (OSTI)

Solar dish/engine systems convert the energy from the sun into electricity at a very high efficiency. Using a mirror array formed into the shape of a dish, the solar dish focuses the sun's rays onto a receiver. The receiver transmits the energy to an engine that generates electric power. Because of the high concentration ratios achievable with parabolic dishes and the small size of the receiver, solar dishes are efficient at collecting solar energy at very high temperatures. Tests of prototype systems and components at locations throughout the US have demonstrated net solar to electric conversion efficiencies as high as 30%. This is significantly higher than any other solar technology.

NONE

1998-04-01T23:59:59.000Z

340

Applications of solar reforming technology  

DOE Green Energy (OSTI)

Research in recent years has demonstrated the efficient use of solar thermal energy for driving endothermic chemical reforming reactions in which hydrocarbons are reacted to form synthesis gas (syngas). Closed-loop reforming/methanation systems can be used for storage and transport of process heat and for short-term storage for peaking power generation. Open-loop systems can be used for direct fuel production; for production of syngas feedstock for further processing to specialty chemicals and plastics and bulk ammonia, hydrogen, and liquid fuels; and directly for industrial processes such as iron ore reduction. In addition, reforming of organic chemical wastes and hazardous materials can be accomplished using the high-efficiency destruction capabilities of steam reforming. To help identify the most promising areas for future development of this technology, we discuss in this paper the economics and market potential of these applications.

Spiewak, I. [Weizmann Inst. of Science, Rehovoth (Israel); Tyner, C.E. [Sandia National Labs., Albuquerque, NM (United States); Langnickel, U. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Koeln (Germany)

1993-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "high-efficiency organic solar" from the National Library of EnergyBeta (NLEBeta).
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to obtain the most current and comprehensive results.


341

Fast Collisionless Reconnection Condition and Self-Organization of Solar Coronal Heating  

E-Print Network (OSTI)

I propose that solar coronal heating is a self-regulating process that keeps the coronal plasma roughly marginally collisionless. The self-regulating mechanism is based on the interplay of two effects. First, plasma density controls coronal energy release via the transition between the slow collisional Sweet-Parker regime and the fast collisionless reconnection regime. This transition takes place when the Sweet--Parker layer becomes thinner than the characteristic collisionless reconnection scale. I present a simple criterion for this transition in terms of the upstream plasma density (n_e), the reconnecting (B_0) and guide (B_z) magnetic field components, and the global length (L) of the reconnection layer: L heating process can be represented by repeating cycles that consist of fast reconnection events (i.e., nanoflares), followed by rapid evaporation episodes, followed by relatively long periods (1-hour) during which magnetic stresses build up and simultaneously the plasma cools down and precipitates.

Dmitri A. Uzdensky

2007-07-09T23:59:59.000Z

342

Low Cost, Light Weight SOlar Modules Based on Organic Photovoltaic Technology  

SciTech Connect

Objectives - In order to produce solar modules for rooftop applications the performance and the lifetime must be improved to 5% - 7% and >10 year life. Task 1 Stability - (1) Flexible modules are stable to 1000 hrs at 65 C/85%RH, (2) Flexible modules in glass are stable to >2000 hrs at 85 C/85%RH (no decrease in performance); (3) Adhesive + filler helps stabilize modules; and (4) Solution coatable barriers exhibit good WVTR; work in-progress. Task 2 Performance: n-type charge carriers - (1) N-type polymers could not be synthesized; and (2) More than 30 fullerene derivatives synthesized and tested, Several deep LUMO derivatives accept charge from deep LUMO polymers, higher voltage observed, Improvement in cell efficiency not observed, morphology problem. Task 3 Performance: grid electrode - (1) Exceeded flatness and roughness goals; (2) Exceeds sheet resistance goals; (3) Achieved %T goals; and (4) Performance equivalent to ITO - 2% Efficiency ( av.); work in-progress.

Russell Gaudiana; David GInley; Robert Birkmeyer

2009-09-20T23:59:59.000Z

343

DOE Solar Decathlon: 2007 Daily Journals  

NLE Websites -- All DOE Office Websites (Extended Search)

Decathlon Director, Richard King, and his wife, Melissa. Richard King, Solar Decathlon organizer, keeps a daily journal during the 2007 Solar Decathlon. Solar Decathlon 2007 Daily...

344

Materials Selection and Processing Techniques for Small Spacecraft Solar Cell Arrays.  

E-Print Network (OSTI)

??Body mounted germanium substrate solar cell arrays form the faces of many small satellite designs to provide the primary power source on orbit. High efficiency… (more)

Torabi, Naseem M.

2013-01-01T23:59:59.000Z

345

Ultraviolet reflector materials for solar detoxification of hazardous waste  

DOE Green Energy (OSTI)

Organic waste detoxification requires cleavage of carbon bonds. Such reactions can be photo-driven by light that is energetic enough to disrupt such bonds. Alternately, light can be used to activate catalyst materials, which in turn can break organic bonds. In either case, photons with wavelengths less than 400 nm are required. Because the terrestrial solar resource below 400 nm is so small (roughly 3% of the available spectrum), highly efficient optical concentrators are needed that can withstand outdoor service conditions. In the past, optical elements for solar application have been designed to prevent ultraviolet (uv) radiation from reaching the reflective layer to avoid the potentially harmful effects of such light on the collector materials themselves. This effectively forfeits the uv part of the spectrum in return for some measure of protection against optical degradation. To optimize the cost/performance benefit of photochemical reaction systems, optical materials must be developed that are not only highly efficient but also inherently stable against the radiation they are designed to concentrate. The requirements of uv optical elements in terms of appropriate spectral bands and level of reflectance are established based upon the needs of photochemical applications. Relevant literature on uv reflector materials is reviewed which, along with discussions with industrial contacts, allows the establishment of a data base of currently available materials. Although a number of related technologies exist that require uv reflectors, to date little attention has been paid to achieving outdoor durability required for solar applications. 49 refs., 3 figs.

Jorgensen, G.; Govindarajan, R.

1991-07-01T23:59:59.000Z

346

Toward high-energy-density, high-efficiency, and moderate-temperature chip-scale thermophotovoltaics  

E-Print Network (OSTI)

The challenging problem of ultra-high-energy-density, high-efficiency, and small-scale portable power generation is addressed here using a distinctive thermophotovoltaic energy conversion mechanism and chip-based system ...

Pilawa-Podgurski, R. C. N.

347

High-efficiency second-harmonic generation in doubly-resonant ?[superscript (2)] microring resonators  

E-Print Network (OSTI)

By directly simulating Maxwell’s equations via the finite-difference time-domain (FDTD) method, we numerically demonstrate the possibility of achieving high-efficiency second harmonic generation (SHG) in a structure ...

Bi, Zhuan-Fang

348

Program on Technology Innovation: Very High Efficiency Photovoltaics Research at IRDEP  

Science Conference Proceedings (OSTI)

This is an interim report on the collaborative activities of Centre National de la Recherche Scientifique (CNRS) and Electricité de France (EDF) R&D to advance the state of high-efficiency photovoltaics (PV). These efforts are principally concerned with basic research to enhance the longer-term prospects of very high-efficiency PV, but they may also produce nearer-term outcomes in the shape of improved conversion efficiency for existing technologies.

2009-03-31T23:59:59.000Z

349

Research on stable, high-efficiency amorphous silicon multijunction modules. Annual subcontract report, 1 January 1991--31 December 1991  

DOE Green Energy (OSTI)

This report describes the progress made during Phase 1 of research and development program to obtain high-efficiency amorphous silicon alloy multijunction modules. Using a large-area deposition system, double-and triple-junction cells were made on stainless steel substrates of over 1 ft{sup 2} area with Ag and ZnO predeposited back reflector. Modules of over 1 ft{sup 2} were produced with between 9.2% and 9.9 initial aperture-area efficiencies as measured under a USSC Spire solar simulator. Efficiencies as measured under the NREL Spire solar simulator were found to be typically 15% to 18% lower. The causes for this discrepancy are now being investigated. The modules show about 15% degradation after 600 hours of one-sun illumination at 50{degrees}C. To optimize devices for higher stabilized efficiency, a new method was developed by which the performance of single-junction cells after long-term, one-sun exposure at 50{degrees}C can be predicted by exposing cells to short-term intense light at different temperatures. This method is being used to optimize the component cells of the multijunction structure to obtain the highest light-degraded efficiency.

Banerjee, A.; Chen, E.; Clough, R.; Glatfelter, T.; Guha, S.; Hammond, G.; Hopson, M.; Jackett, N.; Lycette, M.; Noch, J.; Palmer, T.; Pawlikiewicz, A.; Rosenstein, I.; Ross, R.; Wolf, D.; Xu, X.; Yang, J.; Younan, K.

1992-04-01T23:59:59.000Z

350

Ultrasonically Sprayed and Inkjet Printed Thin Film Electrodes for Organic Solar Cells  

Science Conference Proceedings (OSTI)

Thin film pi-conjugated poly(3,4ethylenedioxythiophene): poly(styrenesulphonate) (PEDOT:PSS) as a hole transport layer on indium tin oxide is a key element in some of the most efficient organic photovoltaic and light emitting devices to date. Films are typically deposited by spincoating, which is not readily scalable. In this paper we investigate the critical parameters for both inkjet and ultrasonic spray deposition of PEDOT:PSS thin films on commercial indium tin oxide as a potentially scalable approach to contact formation. Inkjet parameters investigated include drop spacing and substrate temperature. Ultrasonic spray coating parameters investigated include substrate temperature and solution flow rate. We also show that the ink viscosity has a Newtonian character, making it well suited for inkjet printing. Films were characterized via optical profilometry, sheet resistance and atomic force microscopy. Optimized inkjet printed and ultrasonic sprayed PEDOT:PSS films were then compared to spincast layers in a prototypical bulk heterojunction photovoltaic device employing a poly(3-hexylthiophene) and [6,6]-PCBM (6,6-phenylC61-butyric acid-methyl ester) blend as the absorber. Practically all three approaches produced devices of comparable efficiency. Efficiencies were 3.6%, 3.5% and 3.3% for spin, spray and inkjet depositions respectively.

Steirer, K. X.; Berry, J. J.; Reese, M. O.; van Hest, M. F. A. M.; Miedaner, A.; Liberatore, M. W.; Collins, R. T.; Ginley, D. S.

2009-01-01T23:59:59.000Z

351

SELF-ORGANIZATION OF RECONNECTING PLASMAS TO MARGINAL COLLISIONALITY IN THE SOLAR CORONA  

SciTech Connect

We explore the suggestions by Uzdensky and Cassak et al. that coronal loops heated by magnetic reconnection should self-organize to a state of marginal collisionality. We discuss their model of coronal loop dynamics with a one-dimensional hydrodynamic calculation. We assume that many current sheets are present, with a distribution of thicknesses, but that only current sheets thinner than the ion skin depth can rapidly reconnect. This assumption naturally causes a density-dependent heating rate which is actively regulated by the plasma. We report nine numerical simulation results of coronal loop hydrodynamics in which the absolute values of the heating rates are different but their density dependences are the same. We find two regimes of behavior, depending on the amplitude of the heating rate. In the case that the amplitude of heating is below a threshold value, the loop is in stable equilibrium. Typically, the upper and less dense part of a coronal loop is collisionlessly heated and conductively cooled. When the amplitude of heating is above the threshold, the conductive flux to the lower atmosphere required to balance collisionless heating drives an evaporative flow which quenches fast reconnection, ultimately cooling and draining the loop until the cycle begins again. The key elements of this cycle are gravity and the density dependence of the heating function. Some additional factors are present, including pressure-driven flows from the loop top, which carry a large enthalpy flux and play an important role in reducing the density. We find that on average the density of the system is close to the marginally collisionless value.

Imada, S. [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara-shi, Kanagawa 252-5210 (Japan); Zweibel, E. G. [Departments of Physics and Astronomy and Center for Magnetic Self-Organization, University of Wisconsin-Madison, 475 N Charter Street, Madison, WI 53706 (United States)

2012-08-20T23:59:59.000Z

352

Modeling morphology evolution during solvent-based fabrication of organic solar cells  

E-Print Network (OSTI)

Solvent-based techniques usually involve preparing dilute blends of electron-donor and electron-acceptor materials dissolved in a volatile solvent. After some form of coating onto a substrate, the solvent evaporates. An initially homogeneous mixture separates into electron-acceptor rich and electron-donor rich regions as the solvent evaporates. Depending on the specifics of the blend and processing conditions different morphologies are typically formed. Experimental evidence consistently confirms that the morphology critically affects device performance. A computational framework that can predict morphology evolution can significantly augment experimental analysis. Such a framework will also allow high throughput analysis of the large phase space of processing parameters, thus yielding insight into the process-structure-property relationships. In this paper, we formulate a computational framework to predict evolution of morphology during solvent-based fabrication of organic thin films. This is accomplished by developing a phase field-based model of evaporation-induced and substrate-induced phase-separation in ternary systems. This formulation allows all the important physical phenomena affecting morphology evolution during fabrication to be naturally incorporated. We discuss the various numerical and computational challenges associated with a three dimensional, finite-element based, massively parallel implementation of this framework. This formulation allows, for the first time, to model 3D morphology evolution over large time spans on device scale domains. We illustrate this framework by investigating and quantifying the effect of various process and system variables on morphology evolution. We explore ways to control the morphology evolution by investigating different evaporation rates, blend ratios and interaction parameters between components.

Olga Wodo; Baskar Ganapathysubramanian

2011-09-15T23:59:59.000Z

353

Improved Organic Photovoltaics - Energy Innovation Portal  

Solar Photovoltaic Improved Organic Photovoltaics B4 Materials For Organic Semiconductor Applications, Including Molecular Electronics And Organic Photovoltaics

354

Opening New Avenues for High-Efficiency, Low-Emission Coal Gasification |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Opening New Avenues for High-Efficiency, Low-Emission Coal Opening New Avenues for High-Efficiency, Low-Emission Coal Gasification Opening New Avenues for High-Efficiency, Low-Emission Coal Gasification April 10, 2012 - 1:00pm Addthis A rendering of the Pratt & Whitney Rocketdyne high pressure, dry-solids feed pump. A rendering of the Pratt & Whitney Rocketdyne high pressure, dry-solids feed pump. Washington, DC - Gasification. It's a versatile technology that uses coal to produce power, chemicals, and fuels. Inherently low in air emissions, solid byproducts, and wastewater, commercial gasification plants have proven capable of exceeding the most stringent regulations for air- and solids-emissions. However, capital and operational costs have prohibited the widespread adoption of gasification, especially for power

355

L&E: Participate in a field test for high-efficiency troffer lighting. |  

NLE Websites -- All DOE Office Websites (Extended Search)

Lighting & Electrical » Participate Lighting & Electrical » Participate in a field test for high efficiency troffer lighting Activities Technology Solutions Teams Lighting & Electrical Space Conditioning Plug & Process Loads Food Service Refrigeration Laboratories Energy Management & Information Systems Public Sector Teams Market Solutions Teams Participate in a field test for high-efficiency troffer lighting 50% of all commercial fluorescent lighting fixtures are recessed troffers in 1'x4', 2'x2' and 2'x4' configurations, in operation for more than 10 hours a day on average and collectively consuming more than 87 TWh of electricity annually. The Lighting & Electrical team supported the market introduction of high-efficiency troffers by developing a specification that allows for

356

Distillation: Energy Savings and Other Benefits From the Use of High Efficiency Packings  

E-Print Network (OSTI)

A great deal of attention has been focused lately on the use of high-efficiency packings for distillation applications. This paper discusses benefits that can be derived from the use of these devices. In particular, the reduction in energy requirements for a given separation is addressed for both new and retrofit applications. Pressure loss and product decomposition are also considered, and the basis for an alternative analysis is established. An example is shown in which an existing distillation tray column is retrofitted with a high-efficiency packing. The process advantages achieved, including energy savings, are discussed, as well as the factors governing the selection of the packing. The current limitations on design models for high-efficiency packings with respect to mass transfer efficiency, pressure drop, and capacity in distillation are mentioned briefly. Finally, the applications of these devices to alternative technologies such as liquid-liquid extraction are discussed.

Bravo, J. L.; Fair, J. R.; Humphrey, J. L.

1985-05-01T23:59:59.000Z

357

Key Physical Mechanisms in Nanostructured Solar Cells  

DOE Green Energy (OSTI)

The objective of the project was to study both theoretically and experimentally the excitation, recombination and transport properties required for nanostructured solar cells to deliver energy conversion efficiencies well in excess of conventional limits. These objectives were met by concentrating on three key areas, namely, investigation of physical mechanisms present in nanostructured solar cells, characterization of loss mechanisms in nanostructured solar cells and determining the properties required of nanostructured solar cells in order to achieve high efficiency and the design implications.

Dr Stephan Bremner

2010-07-21T23:59:59.000Z

358

Measured impacts of high efficiency domestic clothes washers in a community  

SciTech Connect

The US market for domestic clothes washers is currently dominated by conventional vertical-axis washers that typically require approximately 40 gallons of water for each wash load. Although the current market for high efficiency clothes washers that use much less water and energy is quite small, it is growing slowly as manufacturers make machines based on tumble action, horizontal-axis designs available and as information about the performance and benefits of such machines is developed and made available to consumers. To help build awareness of these benefits and to accelerate markets for high efficiency washers, the Department of Energy (DOE), under its ENERGY STAR{reg_sign} Program and in cooperation with a major manufacturers of high efficiency washers, conducted a field evaluation of high efficiency washers using Bern, Kansas as a test bed. Baseline washing machine performance data as well as consumer washing behavior were obtained from data collected on the existing machines of more than 100 participants in this instrumented study. Following a 2-month initial study period, all conventional machines were replaced by high efficiency, tumble-action washers, and the study continued for 3 months. Based on measured data from over 20,000 loads of laundry, the impact of the washer replacement on (1) individual customers` energy and water consumption, (2) customers` laundry habits and perceptions, and (3) the community`s water supply and waste water systems were determined. The study, its findings, and how information from the experiment was used to improve national awareness of high efficiency clothes washer benefits are described in this paper.

Tomlinson, J.; Rizy, T.

1998-07-01T23:59:59.000Z

359

Award-Winning Etching Process Cuts Solar Cell Costs (Revised) (Fact Sheet)  

DOE Green Energy (OSTI)

The NREL "black silicon" nanocatalytic wet-chemical etch is an inexpensive, one-step method to minimize reflections from crystalline silicon solar cells. The technology enables high-efficiency solar cells without the use of expensive antireflection coatings.

Not Available

2011-05-01T23:59:59.000Z

360

Identifying Optimal Inorganic Nanomateirals for Hybrid Solar Cells  

DOE Green Energy (OSTI)

As a newly developed photovoltaic technology, organic-inorganic hybrid solar cells have attracted great interest because of the combined advantages from both components. An ideal inorganic acceptor should have a band gap of about 1.5 eV and energy levels of frontier orbitals matching those of the organic polymer in hybrid solar cells. Hybrid density functional calculations are performed to search for optimal inorganic nanomaterials for hybrid solar sells based on poly(3-hexylthiophene) (P3HT). Our results demonstrate that InSb quantum dots or quantum wires can have a band gap of about 1.5 eV and highest occupied molecular orbital level about 0.4 eV lower than P3HT, indicating that they are good candidates for use in hybrid solar cells. In addition, we predict that chalcopyrite MgSnSb{sub 2} quantum wire could be a low-cost material for realizing high-efficiency hybrid solar cells.

Xiang, H.; Wei, S. H.; Gong, X. G.

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "high-efficiency organic solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

L&E - high efficiency lighting for parking structure | The Better Buildings  

NLE Websites -- All DOE Office Websites (Extended Search)

structure structure Activities Technology Solutions Teams Lighting & Electrical Space Conditioning Plug & Process Loads Food Service Refrigeration Laboratories Energy Management & Information Systems Public Sector Teams Market Solutions Teams Adopt high-efficiency lighting for your parking structure Parking structures and garages are typically lighted by older HID lighting technology without any energy-saving controls. The latest high-efficiency alternatives with energy-saving controls-including light-emitting diode (LED), induction, and fluorescent technology options-can save building owners over 40% on their parking lot lighting bills while delivering additional benefits such as better-lighted spaces. The Lighting & Electrical team developed a performance specification that

362

High efficiency coaxial klystron-like relativistic backward wave oscillator with a premodulation cavity  

SciTech Connect

The klystron-like relativistic backward wave oscillator (RBWO) combines the transition radiation with Cerenkov radiation and has demonstrated microwave output of high power and high efficiency. The coaxial slow wave structure device can produce microwave with a lower frequency in a smaller cross section. For the purpose of high efficiency, low frequency, and miniaturization, a coaxial klystron-like RBWO with a premodulation cavity is presented. Particle-in-cell simulations show that a microwave with power of 1.15 GW and frequency of 2.1 GHz is generated with conversion efficiency of 48%, whereas for the device with a reflector, the efficiency is 38%.

Xiao Renzhen; Teng Yan; Chen Changhua; Sun Jun [Science and Technology on High Power Microwave Laboratory, Northwest Institute of Nuclear Technology, Xi'an 710024 (China)

2011-11-15T23:59:59.000Z

363

The design of a high efficiency RF power amplifier for an MCM process  

E-Print Network (OSTI)

In this thesis, I addressed issues arising in the design of a high efficiency RF power amplifier for the Draper Laboratory multi-chip module (MCM) process. A design for a 2.3 GHz PCB amplifier using an enhancement-mode ...

Noonan, James (James Keating)

2005-01-01T23:59:59.000Z

364

Nano Sensor Networks for Tailored Operation of Highly Efficient Gas-To-Liquid Fuels Catalysts  

E-Print Network (OSTI)

Nano Sensor Networks for Tailored Operation of Highly Efficient Gas-To-Liquid Fuels Catalysts Eisa Engineering at University of New South Wales. #12;1 Introduction Gas-to-liquid (GTL) compounds are clean fuels for converting natural gas to the liquid hydrocarbons [1]. However, the reaction is a complex network of many

New South Wales, University of

365

2004 ASHRAE. 3 Standing column wells can be used as highly efficient  

E-Print Network (OSTI)

©2004 ASHRAE. 3 ABSTRACT Standing column wells can be used as highly efficient ground heat Performance Simon J. Rees, Ph.D. Jeffrey D. Spitler, Ph.D., P.E. Zheng Deng Member ASHRAE Member ASHRAE Student Member ASHRAE Carl D. Orio Carl N. Johnson, Ph.D. Member ASHRAE Member ASHRAE Simon J. Rees

366

Effect of High Efficiency Lighting on Power Quality in Public Buildings  

Science Conference Proceedings (OSTI)

This power quality (PQ) case study investigates the effect of high efficiency lighting on PQ in public buildings. The buildings scheduled for lighting retrofits that were involved in this study include a graduate center, a hospital facility, and a social services building.

2003-12-31T23:59:59.000Z

367

High efficient numerical techniques for the earthing design and the analysis of grounded phenomena  

E-Print Network (OSTI)

" or "earthing" system of an electrical substation comprises all interconnected grounding fa- cilitiesHigh efficient numerical techniques for the earthing design and the analysis of grounded phenomena for the computational design of grounding systems of electrical installations in uniform and layered soils

Colominas, Ignasi

368

Hydrogen Production via a High-Efficiency Low-Temperature Reformer  

Science Conference Proceedings (OSTI)

Fuel cells are promoted by the US government as a viable alternative for clean and efficient energy generation. It is anticipated that the fuel cell market will rise if the key technical barriers can be overcome. One of them is certainly fuel processing and purification. Existing fuel reforming processes are energy intensive, extremely complicated and capital intensive; these disadvantages handicap the scale-down of existing reforming process, targeting distributed or on-board/stationary hydrogen production applications. Our project involves the bench-scale demonstration of a high-efficiency low-temperature steam reforming process. Hydrogen production can be operated at 350 to 400şC with our invention, as opposed to >800şC of existing reforming. In addition, our proposed process improves the start-up deficiency of conventional reforming due to its low temperature operation. The objective of this project is to demonstrate the invented process concept via a bench scale unit and verify mathematical simulation for future process optimization study. Under this project, we have performed the experimental work to determine the adsorption isotherm, reaction kinetics, and membrane permeances required to perform the process simulation based upon the mathematical model developed by us. A ceramic membrane coated with palladium thin film fabricated by us was employed in this study. The adsorption isotherm for a selected hydrotalcite adsorbent was determined experimentally. Further, the capacity loss under cyclic adsorption/desorption was confirmed to be negligible. Finally a commercial steam reforming catalyst was used to produce the reaction kinetic parameters required for the proposed operating condition. With these input parameters, a mathematical simulation was performed to predict the performance of the invented process. According to our simulation, our invented hybrid process can deliver 35 to 55% methane conversion, in comparison with the 12 and 18-21% conversion of the packed bed and an adsorptive reactor respectively. In addition CO contamination with energy savings and ~50% capital savings over conventional reforming for fuel cell applications. The pollution abatement potential associated with the implementation of fuel cells, including the elimination of nitrogen oxides and CO, and the reduction in volatile organics and CO2, can thus be realized with the implementation of this invented process. The projected total market size for equipment sale for the proposed process in US is $1.5 billion annually.

Paul KT Liu; Theo T. Tsotsis

2006-05-31T23:59:59.000Z

369

Organization  

NLE Websites -- All DOE Office Websites (Extended Search)

Organization Print Organization Print 2012-12 org chart A complete ALS organization chart (June 2013) is available in PDF. Appointed and elected members of advisory panels provide guidance to Berkeley Lab and ALS management in developing the ALS scientific and user programs. ALS Staff Photo staff photo thumb Click on the image to see a recent photo of ALS staff in front of the dome. The photo was taken on May 14, 2013. ALS Management and Advisory Team Steve Kevan, Deputy Division Director, Science Michael J. Banda, Deputy Division Director, Operations Robert W. Schoenlein, Senior Staff Scientist, Next Generation Light Source Initiative Janos Kirz, Scientific Advisor Paul Adams, Division Deputy for Biosciences ALS Scientific, Technical, and User Support Groups Accelerator Physics

370

Organic photovoltaics and concentrators  

E-Print Network (OSTI)

The separation of light harvesting and charge generation offers several advantages in the design of organic photovoltaics and organic solar concentrators for the ultimate end goal of achieving a lower cost solar electric ...

Mapel, Jonathan King

2008-01-01T23:59:59.000Z

371

Illinois solar energy directory  

SciTech Connect

This Directory contains a listing of Illinois solar energy equipment manufacturers, distributors, installers, consultants, home builders, and alternative energy organizations. Discussions of consumer protection, tax credits, and Illinois solar law are included.

1980-01-01T23:59:59.000Z

372

Simulation of dye solar cells: through and beyond one dimension  

Science Conference Proceedings (OSTI)

In this work we present a Computer Aided Design (CAD) software, called TiberCAD, to simulate Dye Sensitized Solar Cells (DSC). DSCs are particularly interesting devices due to their high efficiency (more than 11% on small area and 8% on large area) and ... Keywords: Drift diffusion, Dye sensitized solar cells, Electrochemistry, Finite element methods, Solar cells

Alessio Gagliardi; Matthias Auf Der Maur; Desiree Gentilini; Aldo Carlo

2011-12-01T23:59:59.000Z

373

Heterojunction solar cells  

DOE Green Energy (OSTI)

A qualitative description of semiconductor/semiconductor heterojunction solar cells is given. The two groups of heterojunctions of greatest economic potential, very highly efficient cells for concentrator applications and moderately efficient thin film cells for flat plates, are described with examples. These examples illustrate the role of heterojunctions in surface passivation, monolithic multijunction devices, devices with semiconductors of only one conductivity type, and low-temperature fabrication techniques.

Wagner, S.

1978-01-01T23:59:59.000Z

374

DOE Solar Decathlon: Sponsors  

NLE Websites -- All DOE Office Websites (Extended Search)

Dow Corning Lowe's M.C. Dean Pepco Schneider Electric Supporting Sponsors Contributing Sponsors Where Are the Houses Now? Quick Links Solar Decathlon Home Solar Decathlon 2011 Solar Decathlon 2009 Solar Decathlon 2007 Solar Decathlon 2005 Solar Decathlon 2002 Solar Decathlon 2011 Sponsors The U.S. Department of Energy (DOE) Solar Decathlon is organized by the National Renewable Energy Laboratory, which works in partnership with sponsors at all levels to make this student solar housing competition and event a reality. 2011 Sustaining Sponsors These sponsors made significant contributions-including financial support, materials, volunteers, outreach, and awards-to the success of Solar Decathlon 2011. Learn more about each sponsor and its role in Solar Decathlon 2011. Dow Corning

375

Archimedes Solar GmbH | Open Energy Information  

Open Energy Info (EERE)

a CPV system based on parabolic mirrors concentrating sunbeams on a high efficiency PV cell. References Archimedes Solar GmbH1 LinkedIn Connections CrunchBase Profile No...

376

Economical Pyrite-Based Solar Cells Vaccine for Prevention and ...  

Background The first generation of solar cells, used in 90% of today's cells, have a focus of high efficiency. These cells use a single p-n junction to extract ...

377

Regulated Emissions from a High Efficiency Spark-Ignition with Maximum Engine Power at or Below 19 KW.  

E-Print Network (OSTI)

??Previous research has developed a set of high efficiency generator engines converted from a stock automobile engine. These all employed different variations of squish and… (more)

Mackey, Travis J

2013-01-01T23:59:59.000Z

378

Program on Technology Innovation: High- Efficiency Photovoltaic Research at IRDEP, 2011  

Science Conference Proceedings (OSTI)

 This report describes the advances of the High-Efficiency Photovoltaic (HEPV) program during 2011. The report focuses on the technical advances in the "up-conversion" program, addressing compounds with improved PV energy-conversion potential. Up-conversion uses materials with special optical properties to convert infrared light that cannot be used by standard PV cells into visible light that the cells can efficiently convert to electricity. Results of experiments on up-conversion ...

2012-08-24T23:59:59.000Z

379

Highly-efficient noise-assisted energy transport in classical oscillator systems  

E-Print Network (OSTI)

Photosynthesis is a biological process that involves the highly-efficient transport of energy captured from the sun to a reaction center, where conversion into useful biochemical energy takes place. Even though one can always use a quantum perspective to describe any physical process, since everything follows the laws of Quantum Mechanics, is the use of quantum theory imperative to explain this high efficiency? Making use of the quantum-classical correspondence of electronic energy transfer recently introduced by Eisfeld and Briggs [Phys. Rev. E 85, 046118 (2012)], we show here that the highly-efficient noise-assisted energy transport described by Rebentrost et al. [New J. Phys. 11, 033003 (2009)], and Plenio and Huelga [New J. Phys. 10, 113019 (2008)], as the result of the interplay between the quantum coherent evolution of the photosynthetic system and noise introduced by its surrounding environment, it can be found as well in purely classical systems. The wider scope of applicability of the enhancement of energy transfer assisted by noise might open new ways for developing new technologies aimed at enhancing the efficiency of a myriad of energy transfer systems, from information channels in micro-electronic circuits to long-distance high-voltage electrical lines.

R. de J. León-Montiel; Juan P. Torres

2013-01-08T23:59:59.000Z

380

Kieffer Paper Mill's Recycled Fiber Mill and PSI Energy's High Efficiency Motors Plan  

E-Print Network (OSTI)

The needs of electricity consumers along with the utility industry are rapidly changing. Consumers want electricity to perform more functions, improve efficiencies and help lower the cost of production, all in an environmentally responsible manner. In 1991, PSI Energy developed a comprehensive Demand-Side Management program, called Energy Matters™, aimed at improving the overall end-use efficiency of its customers. Its goal is to reduce summer peak demand 120 megawatts by the summer of 1995. Kieffer Paper Mills in Brownstown, IN had a need to address the efficiency of its new, state-of-the-art pulp processing mill that it was building. With over 4,000 horsepower of process motors going into the new plant, even a modest improvement in motor efficiency would yield significant energy savings. PSI Energy was able to help Kieffer examine the economics of high efficiency motors, and through the PSI Energy High Efficiency Motors Plan encouraged Kieffer Paper Mills to purchase energy efficient motors by helping pay part of the cost differential between high efficiency and standard efficiency models.

Myers, J. A.

1993-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "high-efficiency organic solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

High-efficiency, monolithic, multi-bandgap, tandem photovoltaic energy converters  

DOE Patents (OSTI)

A monolithic, multi-bandgap, tandem solar photovoltaic converter has at least one, and preferably at least two, subcells grown lattice-matched on a substrate with a bandgap in medium to high energy portions of the solar spectrum and at least one subcell grown lattice-mismatched to the substrate with a bandgap in the low energy portion of the solar spectrum, for example, about 1 eV.

Wanlass, Mark W. (Golden, CO)

2011-11-29T23:59:59.000Z

382

Phase II Final Project Report SBIR Project: "A High Efficiency PV to Hydrogen Energy System"  

Science Conference Proceedings (OSTI)

The innovative research conducted for this project contributed greatly to the understanding of generating low-cost hydrogen from solar energy. The project’s research identified two highly leveraging and complementary pathways. The first pathway is to dramatically increase the efficiency of converting sunlight into electricity. Improving solar electric conversion efficiency directly increases hydrogen production. This project produced a world record efficiency for silicon solar cells and contributed to another world record efficiency for a solar concentrator module using multijunction solar cells. The project’s literature review identified a second pathway in which wasted heat from the solar concentration process augments the electrolysis process generating hydrogen. One way to do this is to use a “heat mirror” that reflects the heat-producing infrared and transmits the visible spectrum to the solar cells; this also increases solar cell conversion efficiency. An economic analysis of this concept confirms that, if long-term concentrator photovoltaic (CPV) and solid-oxide electrolyzer cost goals can be achieved, hydrogen will be produced from solar energy cheaper than the cost of gasoline. The potential public benefits from this project are significant. The project has identified a potential energy source for the nation’s future electricity and transportation needs that is entirely “home grown” and carbon free. As CPV enter the nation’s utility markets, the opportunity for this approach to be successful is greatly increased. Amonix strongly recommends further exploration of this project’s findings.

Slade, A; Turner, J; Stone, K; McConnell, R

2008-09-02T23:59:59.000Z

383

Hydrogen Production via a High-Efficiency Low-Temperature Reformer  

DOE Green Energy (OSTI)

Fuel cells are promoted by the US government as a viable alternative for clean and efficient energy generation. It is anticipated that the fuel cell market will rise if the key technical barriers can be overcome. One of them is certainly fuel processing and purification. Existing fuel reforming processes are energy intensive, extremely complicated and capital intensive; these disadvantages handicap the scale-down of existing reforming process, targeting distributed or on-board/stationary hydrogen production applications. Our project involves the bench-scale demonstration of a high-efficiency low-temperature steam reforming process. Hydrogen production can be operated at 350 to 400şC with our invention, as opposed to >800şC of existing reforming. In addition, our proposed process improves the start-up deficiency of conventional reforming due to its low temperature operation. The objective of this project is to demonstrate the invented process concept via a bench scale unit and verify mathematical simulation for future process optimization study. Under this project, we have performed the experimental work to determine the adsorption isotherm, reaction kinetics, and membrane permeances required to perform the process simulation based upon the mathematical model developed by us. A ceramic membrane coated with palladium thin film fabricated by us was employed in this study. The adsorption isotherm for a selected hydrotalcite adsorbent was determined experimentally. Further, the capacity loss under cyclic adsorption/desorption was confirmed to be negligible. Finally a commercial steam reforming catalyst was used to produce the reaction kinetic parameters required for the proposed operating condition. With these input parameters, a mathematical simulation was performed to predict the performance of the invented process. According to our simulation, our invented hybrid process can deliver 35 to 55% methane conversion, in comparison with the 12 and 18-21% conversion of the packed bed and an adsorptive reactor respectively. In addition CO contamination with <10 to 120 ppm is predicted for the invented process depending upon the cycle time for the PSA type operation. In comparison, the adsorption reactor can also deliver a similar CO contaminant at the low end; however, its high end reaches as high as 300 ppm based upon the simulation of our proposed operating condition. Our experimental results for the packed bed and the membrane reactor deliver 12 and 18% conversion at 400°C, approaching the conversion by the mathematical simulation. Due to the time constraint, the experimental study on the conversion of the invented process has not been complete. However, our in-house study using a similar process concept for the water gas shift reaction has demonstrated the reliability of our mathematical simulation for the invented process. In summary, we are confident that the invented process can deliver efficiently high purity hydrogen at a low temperature (~400°C). According to our projection, the invented process can further achieve 5% energy savings and ~50% capital savings over conventional reforming for fuel cell applications. The pollution abatement potential associated with the implementation of fuel cells, including the elimination of nitrogen oxides and CO, and the reduction in volatile organics and CO2, can thus be realized with the implementation of this invented process. The projected total market size for equipment sale for the proposed process in US is $1.5 billion annually.

Paul KT Liu; Theo T. Tsotsis

2006-05-31T23:59:59.000Z

384

Concentrating Solar Power  

Science Conference Proceedings (OSTI)

Oct 10, 2012 ... Program Organizers: Mariappan Paranthaman, Oak Ridge National Laboratory; Winnie Wong-Ng, NIST; Urs Schoop, Global Solar Energy; ...

385

AC conductivity of nanoporous metal-oxide photoanodes for solar energy conversion  

E-Print Network (OSTI)

AC conductivity of nanoporous metal-oxide photoanodes for solar energy conversion Steven J. Konezny and SnO2 play a central role in solar energy conversion applications.1­7 In fact, the discovery of low-cost high-efficiency dye-sensitized solar cells (DSSCs) (i.e., exceeding 10% solar-to-electric energy

386

Structure of All-Polymer Solar Cells Impedes Efficiency  

NLE Websites -- All DOE Office Websites (Extended Search)

Structure of All-Polymer Solar Cells Impedes Efficiency Print Organic solar cells are made of thin layers of interpenetrating structures from two different conducting organic...

387

High efficiency shale oil recovery. Final report, January 1, 1992--June 30, 1993  

SciTech Connect

The Adams Counter-current shale oil recovery process is an improved retorting technology enabling highly efficient oil recovery from oil shale. The high efficiency results primarily from the following facts: it (1) recovers the ash heat to preheat the feed ore; (2) burns and uses the coke energy and (3) operates without using hot ash recycling as a heat carrier. This latter feature is doubly important, contributing to high oil yield and to the generation of highly reactive coke which can be burned below 1000{degree}F, avoiding the endothermal calcination of the mineral carbonates and helping to clean the ash of contaminants. This project demonstrates that oil shale can be retorted under the specified conditions and achieve the objectives of very high efficiency. The project accomplished the following: 51 quartz sand rotary kiln runs provided significant engineering data. A heat transfer value of 107 Btu/hr/ft{sup 2}/{degree}F was obtained at optimum RPM; eight oil shale samples were obtained and preliminary shakedown runs were made. Five of the samples were selected for kiln processing and twelve pyrolysis runs were made on the five different oil shales;average off recovery was 109% of Fisher Assay; retorted residue from all five samples was oxidized at approximately 1000{degree}F. The ash from these runs was oxidized to varying extents, depending on the oil shale and oxidizing temperatures. While 1000{degree}F is adequately hot to provide process heat from coke combustion for these ores, some Eastern oil shales, without mineral carbonates, may be oxidized at higher temperatures, perhaps 100--300 degrees hotter, to obtain a more complete oxidation and utilization of the coke.

Adams, D.C.

1993-09-29T23:59:59.000Z

388

Expert Meeting Report: Achieving the Best Installed Performance from High-Efficiency Residential Gas Furnaces  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Achieving the Best Installed Performance from High- Efficiency Residential Gas Furnaces Larry Brand Partnership for Advanced Residential Retrofit (PARR) March 2012 NOTICE This report was prepared as an account of work sponsored by an agency of the United States government. Neither the United States government nor any agency thereof, nor any of their employees, subcontractors, or affiliated partners makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade

389

L&E: Adopt high-efficiency lighting for your parking lot | The Better  

NLE Websites -- All DOE Office Websites (Extended Search)

lot lot Activities Technology Solutions Teams Lighting & Electrical Space Conditioning Plug & Process Loads Food Service Refrigeration Laboratories Energy Management & Information Systems Public Sector Teams Market Solutions Teams Adopt high-efficiency lighting for your parking lot Most parking lots are illuminated by older high-intensity discharge (HID) lighting technology without any energy-saving controls. New light-emitting diode (LED) technology can cut parking lot lighting energy bills by 40%, or much more with controls, while delivering additional benefits including long life, reduced maintenance costs, and improved lighting uniformity. The Lighting & Electrical team developed a performance specification to help building owners take advantage of these improved lighting

390

Highly efficient coupling of photons from nanoemitters into single-mode optical fibers  

E-Print Network (OSTI)

Highly efficient coupling of photons from nanoemitters into single-mode optical fibers is demonstrated using tapered fibers. 7.4 +/- 1.2 % of the total emitted photons from single CdSe/ZnS nanocrystals were coupled into a 300-nm-diameter tapered fiber. The dependence of the coupling efficiency on the taper diameter was investigated and the coupling efficiency was found to increase exponentially with decreasing diameter. This method is very promising for nanoparticle sensing and single-photon sources.

Masazumi Fujiwara; Kiyota Toubaru; Tetsuya Noda; Hong-Quan Zhao; Shigeki Takeuchi

2012-09-12T23:59:59.000Z

391

High Efficient Secret Key Distillation for Long Distance Continuous Variable Quantum Key Distribution  

E-Print Network (OSTI)

The continuous variable quantum key distribution is expected to provide high secret key rate without single photon source and detector, but the lack of the secure and effective key distillation method makes it unpractical. Here, we present a secure single-bit-reverse-reconciliation protocol combined with secret information concentration and post-selection, which can distill the secret key with high efficiency and low computational complexity. The simulation results show that this protocol can provide high secret key rate even when the transmission fiber is longer than 150km, which may make the continuous variable scheme to outvie the single photon one.

Yi-bo Zhao; Zheng-fu Han; Jin-jian Chen; You-zhen Gui; Guang-can Guo

2006-03-08T23:59:59.000Z

392

Development of an advanced high efficiency coal combustor for boiler retrofit. Summary report  

Science Conference Proceedings (OSTI)

The objective of the program was to develop an advanced coal combustion system for firing beneficiated coal fuels (BCFs) capable of being retrofitted to industrial boilers originally designed for firing natural gas. The High Efficiency Advanced Coal Combustor system is capable of firing microfine coal-water fuel (MCWF), MCWF with alkali sorbent (for SO{sub 2} reduction), and dry microfine coal. Design priorities for the system were that it be simple to operate and offer significant reductions in NO{sub x}, SO{sub x}, and particulate emissions as compared with current coal-fired combustor technology. (VC)

LaFlesh, R.C.; Rini, M.J.; McGowan, J.G.; Beer, J.M.; Toqan, M.A.

1990-04-01T23:59:59.000Z

393

Development of an advanced high efficiency coal combustor for boiler retrofit  

Science Conference Proceedings (OSTI)

The objective of the program was to develop an advanced coal combustion system for firing beneficiated coal fuels (BCFs) capable of being retrofitted to industrial boilers originally designed for firing natural gas. The High Efficiency Advanced Coal Combustor system is capable of firing microfine coal-water fuel (MCWF), MCWF with alkali sorbent (for SO{sub 2} reduction), and dry microfine coal. Design priorities for the system were that it be simple to operate and offer significant reductions in NO{sub x}, SO{sub x}, and particulate emissions as compared with current coal-fired combustor technology. (VC)

LaFlesh, R.C.; Rini, M.J.; McGowan, J.G.; Beer, J.M.; Toqan, M.A.

1990-04-01T23:59:59.000Z

394

High-Efficiency Solar Cells for Large-Scale Electricity Generation & Design Considerations for the Related Optics (Presentation)  

SciTech Connect

The photovoltaic industry has been growing exponentially at an average rate of about 35%/year since 1979. Recently, multijunction concentrator cell efficiencies have surpassed 40%. Combined with concentrating optics, these can be used for electricity generation.

Kurtz, S.; Olson, J.; Geisz, J.; Friedman, D.; McMahon, W.; Ptak, A.; Wanlass, M.k; Kibbler, A.; Kramer, C.; Ward, S.; Duda, A.; Young, M.; Carapella, J.

2007-09-17T23:59:59.000Z

395

Back-Surface Passivation for High-Efficiency Crystalline Silicon Solar Cells: Final Technical Progress Report, September 2010 -- May 2012  

DOE Green Energy (OSTI)

Final technical progress report for TetraSun, a Photovoltaic Technology Incubator awardee within the U.S. Department of Energy's (DOE) SunShot Program.

Schultz-Wittmann, O.

2012-07-01T23:59:59.000Z

396

Manufacturing of High-Efficiency Bi-Facial Tandem Concentrator Solar Cells: February 20, 2009--August 20, 2010  

DOE Green Energy (OSTI)

Spire Semiconductor made concentrator photovoltaic (CPV) cells using a new bi-facial growth process and met both main program goals: a) 42.5% efficiency 500X (AM1.5D, 25C, 100mW/cm2); and b) Ready to supply at least 3MW/year of such cells at end of program. We explored a unique simple fabrication process to make a N/P 3-junction InGaP/GaAs/InGaAs tandem cells . First, the InGaAs bottom cell is grown on the back of a GaAs wafer. The wafers are then loaded into a cassette, spin-rinsed to remove particles, dipped in dilute NH4OH and spin-dried. The wafers are then removed from the cassette loaded the reactor for GaAs middle and InGaP top cell growth on the opposite wafer face (bi-facial growth). By making the epitaxial growth process a bit more complex, we are able to avoid more complex processing (such as large area wafer bonding or epitaxial liftoff) used in the inverted metamorphic (IMM) approach to make similar tandem stacks. We believe the yield is improved compared to an IMM process. After bi-facial epigrowth, standard III-V cell steps (back metal, photolithography for front grid, cap etch, AR coat, dice) are used in the remainder of the process.

Wojtczuk , S.

2011-06-01T23:59:59.000Z

397

High efficiency thin film CdTe solar cells. Second quarterly progress report, June 19-September 18, 1979  

DOE Green Energy (OSTI)

During the second quarter of this program primary emphasis was put into depositing and evaluating both n and p-type CdTe films on a variety of conducting and non-conducting substrates. Improvements in the deposition apparatus permitted preparation of a large number of CdTe films and numerous analytic techniques available at Tufts University were utilized to examine these films. It was found that the introduction of a thin (100 A). In layer between the ITO and the CdTe significantly reduced the previously observed barrier present at the ITO/n-CdTe interface without adversely reducing optical transmission. While the resistivity of the films is still rather high, very recent results show that proper changes in procedure are capable of markedly lowering the resistivity. Preliminary Schottky barrier devices have been made which show promising photovoltaic characteristics.

Serreze, H.B.; Entine, G.; Goldner, R.B.

1979-10-01T23:59:59.000Z

398

Method of fabricating high-efficiency Cu(In,Ga)(Se,S){sub 2} thin films for solar cells  

DOE Patents (OSTI)

A process for producing a slightly Cu-poor thin film of Cu(In,Ga)(Se,S){sub 2} comprises depositing a first layer of (In,Ga){sub x} (Se,S){sub y} followed by depositing just enough Cu+(Se,S) or Cu{sub x} (Se,S) to produce the desired slightly Cu-poor material. In a variation, most, but not all, (about 90 to 99%) of the (In,Ga){sub x} (Se,S){sub y} is deposited first, followed by deposition of all the Cu+(Se,S) or Cu{sub x} (Se,S) to go near stoichiometric, possibly or even preferably slightly Cu-rich, and then in turn followed by deposition of the remainder (about 1 to 10%) of the (In,Ga){sub x} (Se,S){sub y} to end with a slightly Cu-poor composition. In yet another variation, a small portion (about 1 to 10%) of the (In,Ga){sub x} (Se,S){sub y} is first deposited as a seed layer, followed by deposition of all of the Cu+(Se,S) or Cu{sub x} (Se,S) to make a very Cu-rich mixture, and then followed deposition of the remainder of the (In,Ga){sub x} (Se,S){sub y} to go slightly Cu-poor in the final Cu(In,Ga)(Se,S){sub 2} thin film. 5 figs.

Noufi, R.; Gabor, A.M.; Tuttle, J.R.; Tennant, A.L.; Contreras, M.A.; Albin, D.S.; Carapella, J.J.

1995-08-15T23:59:59.000Z

399

Preparation of copper-indium-gallium-diselenide precursor films by electrodeposition for fabricating high efficiency solar cells  

DOE Patents (OSTI)

A photovoltaic cell exhibiting an overall conversion efficiency of 13.6% is prepared from a copper-indium-gallium-diselenide precursor thin film. The film is fabricated by first simultaneously electrodepositing copper, indium, gallium, and selenium onto a glass/molybdenum substrate (12/14). The electrodeposition voltage is a high frequency AC voltage superimposed upon a DC voltage to improve the morphology and growth rate of the film. The electrodeposition is followed by physical vapor deposition to adjust the final stoichiometry of the thin film to approximately Cu(In.sub.1-n Ga.sub.x)Se.sub.2, with the ratio of Ga/(In+Ga) being approximately 0.39.

Bhattacharya, Raghu N. (Littleton, CO); Hasoon, Falah S. (Arvada, CO); Wiesner, Holm (Golden, CO); Keane, James (Lakewood, CO); Noufi, Rommel (Golden, CO); Ramanathan, Kannan (Golden, CO)

1999-02-16T23:59:59.000Z

400

Growth and development of GaInAsP for use in high-efficiency solar cells  

DOE Green Energy (OSTI)

This report describes work done during Phase II of the subcontract. Goals for Phase II include the following: (1) Optimize the GaInAsP cell on GaAs and demonstrate a 500-sun at air mass (AM) 1.5 efficiency of >23%. (2) Develop a window layer, including the evaluation of AlGaAs, GaInP, AlGaAsP, AlGaInP, and GaP. (3) Develop a front-surface contact, with a grid designed for 500-sun concentration, and a goal of a contact resistivity of [approximately]10[sup 5] ohm-cm[sup 2]. (4) Grow GaInAsP cells on Ge, with a goal of a 1-sun (AM 1.5) efficiency of >15%. Accomplishments reported herein include (1) the fabrication of p-on-n and n-on-p GaInAsP cells on GaAs, with the n-on-p cell demonstrating a 10-sun (AM 1.5) active-area efficiency of 23.4% as measured at NREL (2) the evaluation of Al[sub x]Ga([sub 1-x])As, GaInP[sub 2], and AlInP[sub 2] window layers; and (3) the fabrication of GaInAsP cells on Ge, with the demonstration of a p-on-n GaInAsP cell grown on Ge with a 1-sun (AM 1.5) active-area efficiency of 14.4%.

Sharps, P.R. (Research Triangle Inst., Research Triangle Park, NC (United States))

1993-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "high-efficiency organic solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

HIGH EFFICIENCY AMORPHOUS SILICON GERMANIUM SOLAR CELLS X. Liao, W. Du, X. Yang, H. Povolny, X. Xiang and X. Deng  

E-Print Network (OSTI)

-layer/ ITO. The a-SiGe absorber i-layers were deposited using a gas mixture of disilane, germane and hydrogen with a varying germane to disilane ratio and a hydrogen dilution of 50-100. The illuminated I-V measurement

Deng, Xunming

402

High Throughput, Low Toxic Processing of Very Thin, High Efficiency CIGSS Solar Cells: Final Report, December 2008  

DOE Green Energy (OSTI)

The work carried out during this project presents the use of diethylselenium or other organometallic precursors as low-toxicity alternative selenium sources for preparing a high-quality absorber.

Dhere, N. G.

2009-04-01T23:59:59.000Z

403

Singlet-Fission Sensitizers for Ultra-High Efficiency Excitonic Solar Cells: 15 August 2005 - 14 October 2008  

DOE Green Energy (OSTI)

We have considered the potential benefits offered by using singlet fission sensitizers in photovoltaic cells and identified two key issues involved in the search for such sensitizers.

Michl, J.

2008-12-01T23:59:59.000Z

404

Process Optimization for High Efficiency Heterojunction c-Si Solar Cells Fabrication Using Hot-Wire Chemical Vapor Deposition: Preprint  

SciTech Connect

The researchers extensively studied the effects of annealing or thermal history of cell process on the minority carrier lifetimes of FZ n-type c-Si wafers with various i-layer thicknesses from 5 to 60 nm, substrate temperatures from 100 to 350 degrees C, doped layers both p- and n-types, and transparent conducting oxide (TCO).

Ai, Y.; Yuan, H. C.; Page, M.; Nemeth, W.; Roybal, L.; Wang, Q.

2012-06-01T23:59:59.000Z

405

Method of fabricating high-efficiency Cu(In,Ga)(SeS).sub.2 thin films for solar cells  

DOE Patents (OSTI)

A process for producing a slightly Cu-poor thin film of Cu(In,Ga)(Se,S).sub.2 comprises depositing a first layer of (In,Ga).sub.x (Se,S).sub.y followed by depositing just enough Cu+(Se,S) or Cu.sub.x (Se,S) to produce the desired slightly Cu-poor material. In a variation, most, but not all, (about 90 to 99%) of the (In,Ga).sub.x (Se,S).sub.y is deposited first, followed by deposition of all the Cu+(Se,S) or Cu.sub.x (Se,S) to go near stoichiometric, possibly or even preferably slightly Cu-rich, and then in turn followed by deposition of the remainder (about 1 to 10%) of the (In,Ga).sub.x (Se,S).sub.y to end with a slightly Cu-poor composition. In yet another variation, a small portion (about 1 to 10%) of the (In,Ga).sub.x (Se,S).sub.y is first deposited as a seed layer, followed by deposition of all of the Cu+(Se,S) or Cu.sub.x (Se,S) to make a very Cu-rich mixture, and then followed deposition of the remainder of the (In,Ga).sub.x (Se,S).sub.y to go slightly Cu-poor in the final Cu(In,Ga)(Se,S).sub.2 thin film.

Noufi, Rommel (Golden, CO); Gabor, Andrew M. (Boulder, CO); Tuttle, John R. (Denver, CO); Tennant, Andrew L. (Denver, CO); Contreras, Miguel A. (Golden, CO); Albin, David S. (Denver, CO); Carapella, Jeffrey J. (Evergreen, CO)

1995-01-01T23:59:59.000Z

406

Ideal Configuration For Nanoscale Solar Cells - Energy ...  

Technology Marketing Summary The standard design of excitonic solar cells, which includes most organic-based solar cells, is ideal in only two out of ...

407

Solar dish/engine systems  

DOE Green Energy (OSTI)

Solar dish/engine systems convert the energy from the sun into electricity at a very high efficiency. Using a mirror array formed into the shape of a dish, the solar dish focuses the sun`s rays onto a receiver. The receiver transmits the energy to an engine that generates electric power. Because of the high concentration ratios achievable with parabolic dishes and the small size of the receiver, solar dishes are efficient at collecting solar energy at very high temperatures. Tests of prototype systems and components at locations throughout the US have demonstrated net solar to electric conversion efficiencies as high as 30%. This is significantly higher than any other solar technology.

Not Available

1998-04-01T23:59:59.000Z

408

Solar Neutrinos in 2011  

E-Print Network (OSTI)

I give an overview of the recent developments in the solar neutrino field. I focus on the Borexino detector, which has uncovered the solar neutrino spectrum below 5 MeV, providing new tests and confirmation for solar neutrino oscillations. I report on the updated measurements of the 8B solar neutrino flux by water Cherenkov and organic scintillator detectors. I review the precision measurement of the 7Be solar neutrino flux by Borexino and the search for its day-night asymmetry. I present Borexino's latest result on the study of pep and CNO neutrinos. Finally, I discuss the outstanding questions in the field and future solar neutrino experiments.

Chavarria, Alvaro

2012-01-01T23:59:59.000Z

409

Cost Effective, High Efficiency Integrated Systems Approach to Auxilliary Electric Motors  

DOE Green Energy (OSTI)

The CARAT program, carried out by Kinetic Art & Technology Corporation (KAT), has been one of the most commercially successful KAT R&D programs to date. Based on previous development of its technology, KAT designed, constructed and tested a highly efficient motor and controller system under this CARAT program with supplemental commercial funding. Throughout this CARAT effort, the technical objectives have been refined and refocused. Some objectives have been greatly expanded, while others have been minimized. The determining factor in all decisions to refocus the objectives was the commercial need, primarily the needs of KAT manufacturing partners. Several companies are employing the resulting CARAT motor and controller designs in prototypes for commercial products. Two of these companies have committed to providing cost share in order to facilitate the development. One of these companies is a major manufacturing company developing a revolutionary new family of products requiring the ultra-high system efficiency achievable by the KAT motor and controller technologies (known as Segmented ElectroMagnetic Array, or SEMA technology). Another company requires the high efficiency, quiet operation, and control characteristics afforded by the same basic motor and controller for an advanced air filtration product. The combined annual production requirement projected by these two companies exceeds one million units by 2005.

Roy Kessinger Jr.; Keith Seymour; Kanchan Angal; Jason Wolf; Steve Brewer; Leonard Schrank

2003-09-26T23:59:59.000Z

410

The high-efficiency ?-ray spectroscopy setup ?3 at HI?S  

E-Print Network (OSTI)

The existing Nuclear Resonance Fluorescence (NRF) setup at the HI{\\gamma}S facility at the Triangle Universities Nuclear Laboratory at Duke University has been extended in order to perform {\\gamma}-{\\gamma} coincidence experiments. The new setup combines large volume LaBr3:Ce detectors and high resolution HPGe detectors in a very close geometry to offer high efficiency, high energy resolution as well as high count rate capabilities at the same time. The combination of a highly efficient {\\gamma}-ray spectroscopy setup with the mono-energetic high-intensity photon beam of HI{\\gamma}S provides a worldwide unique experimental facility to investigate the {\\gamma}-decay pattern of dipole excitations in atomic nuclei. The performance of the new setup has been assessed by studying the nucleus \\sulfur at 8.125 MeV beam energy. The {\\gamma}-decay branching ratio from the $1^+$ level at 8125.4 keV to the first excited $2^+$ state was determined to 15.7(3)%.

Bastian Löher; Vera Derya; Thomas Aumann; Jacob Beller; Nathan Cooper; Marc Duchene; Janis Endres; Enrico Fiori; Johann Isaak; John Kelley; Michael Knörzer; Norbert Pietralla; Christopher Romig; Marcus Scheck; Heiko Scheit; Joel Silva; Anton P. Tonchev; Werner Tornow; Henry Weller; Volker Werner; Andreas Zilges

2013-04-23T23:59:59.000Z

411

New III-V cell design approaches for very high efficiency. Annual subcontract report, 1 August 1991--31 July 1992  

DOE Green Energy (OSTI)

This report describes to examine new solar cell desip approaches for achieving very high conversion efficiencies. The program consists of two elements. The first centers on exploring new thin-film approaches specifically designed for M-III semiconductors. Substantial efficiency gains may be possible by employing light trapping techniques to confine the incident photons, as well as the photons emitted by radiative recombination. The thin-film approach is a promising route for achieving substantial performance improvements in the already high-efficiency, single-junction, III-V cell. The second element of the research involves exploring desip approaches for achieving high conversion efficiencies without requiring extremely high-quality material. This work has applications to multiple-junction cells, for which the selection of a component cell often involves a compromise between optimum band pp and optimum material quality. It could also be a benefit manufacturing environment by making the cell`s efficiency less dependent on materialquality.

Lundstrom, M.S.; Melloch, M.R.; Lush, G.B.; Patkar, M.P.; Young, M.P. [Purdue Univ., Lafayette, IN (United States)

1993-04-01T23:59:59.000Z

412

Plasmonic excitation of organic double heterostructure solar cells J. K. Mapel, M. Singh, and M. A. Baldoa  

E-Print Network (OSTI)

March 2007 The authors demonstrate that thin film organic photovoltaic cells are efficient detectors quantum efficiency in fullerene­copper phthalocyanine photovoltaic cells is doubled at resonance to 12 polaritons SPPs . The transduction ele- ment is a thin film organic photovoltaic cell.2 Under conven- tional

413

GaNPAs Solar Cells that Can Be Lattice-Matched to Silicon  

DOE Green Energy (OSTI)

III-V semiconductors grown on silicon substrates are very attractive for lower-cost, high-efficiency multijunction solar cells, but lattice-mismatched alloys that result in high dislocation densities have been unable to achieve satisfactory performance. GaNxP1-x-yAsy is a direct-gap III-V alloy that can be grown lattice-matched to Si when y= 4.7x - 0.1. We have proposed the use of lattice-matched GaNPAs on silicon for high-efficiency multijunction solar cells. We have grown GaNxP1-x-yAsy on GaP (with a similar lattice constant to silicon) by metal-organic chemical vapor phase epitaxy with direct bandgaps in the range of 1.5 to 2.0 eV. We have demonstrated the performance of single-junction GaNxP1-x-yAsy solar cells grown on GaP substrates and shown improvements in material quality by reducing carbon and hydrogen impurities through optimization of growth conditions. We have achieved quantum efficiencies (QE) in these cells as high as 60% and PL lifetimes as high as 3.0 ns.

Geisz, J. F.; Friedman, D. J.; McMahon, W. E.; Ptak, A. J.; Kibbler, A. E.; Olson, J. M.; Kurtz, S.; Kramer, C.; Young, M.; Duda, A.; Reedy, R. C.; Keyes, B. M.; Dippo, P.; Metzger, W. K.

2003-05-01T23:59:59.000Z

414

Game-Changing Advancements in Solar Energy | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Game-Changing Advancements in Solar Energy Game-Changing Advancements in Solar Energy Game-Changing Advancements in Solar Energy Addthis Record-Breaking Solar 1 of 5 Record-Breaking Solar This concentrating photovoltaic (CPV) cell -- which uses a focused lens to magnify light to 418 times the intensity of the sun -- earned an R&D100 Award and set a new world record of 43.5 percent for solar cell conversion efficiency. The technology is based on high-efficiency multijunction research pioneered by the National Renewable Energy Laboratory (NREL). | Photo by Daniel Derkacs/Solar Junction. Date taken: 2012-11-29 09:21 Solar Innovation 2 of 5 Solar Innovation Solar Junction's record-breaking SJ3 solar cell is based on EERE-supported multijunction research. | Photo by Daniel Derkacs/Solar Junction Date taken: 2012-11-29 09:21

415

Solar Energy Market Forecast | Open Energy Information  

Open Energy Info (EERE)

Solar Energy Market Forecast Solar Energy Market Forecast Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Solar Energy Market Forecast Agency/Company /Organization: United States Department of Energy Sector: Energy Focus Area: Solar Topics: Market analysis, Technology characterizations Resource Type: Publications Website: giffords.house.gov/DOE%20Perspective%20on%20Solar%20Market%20Evolution References: Solar Energy Market Forecast[1] Summary " Energy markets / forecasts DOE Solar America Initiative overview Capital market investments in solar Solar photovoltaic (PV) sector overview PV prices and costs PV market evolution Market evolution considerations Balance of system costs Silicon 'normalization' Solar system value drivers Solar market forecast Additional resources"

416

Economic On-Grid Solar Energy via Organic Thin Film Technology: 28 September 2007 - 27 October 2008  

DOE Green Energy (OSTI)

Plextronics' PV Incubator goal was to take its organic photovoltaic technology from lab-scale and demonstrate a pathway to 3-W manufacturing capacity (~2010) and 7 cents/kWh LCOE by 2015.

Laird, D.; Bernkopf, J.; Jian, S.; Krieg, J.; Li, S.; McGuiness, C.; Rossier, J.; Storch, M.; Ripnis, R.; Tuttle, R.; Woodworth, B.; Williams, S.

2009-12-01T23:59:59.000Z

417

Extreme Chromatography: Faster, Hotter, SmallerChapter 5 High-efficiency Liquid Chromatography Separations Achieved by Monolithic Silica Columns  

Science Conference Proceedings (OSTI)

Extreme Chromatography: Faster, Hotter, Smaller Chapter 5 High-efficiency Liquid Chromatography Separations Achieved by Monolithic Silica Columns Methods and Analyses eChapters Methods - Analyses Books AOCS Press Downloada

418

Simulation of a High Efficiency Multi-bed Adsorption Heat Pump  

Science Conference Proceedings (OSTI)

Attaining high energy efficiency with adsorption heat pumps is challenging due to thermodynamic losses that occur when the sorbent beds are thermally cycled without effective heat recuperation. The multi-bed concept described here effectively transfers heat from beds being cooled to beds being heated, which enables high efficiency in thermally driven heat pumps. A simplified lumped-parameter model and detailed finite element analysis are used to simulate the performance of an ammonia-carbon sorption compressor, which is used to project the overall heat pump coefficient of performance. The effects of bed geometry and number of beds on system performance are explored, and the majority of the performance benefit is obtained with four beds. Results indicate that a COP of 1.24 based on heat input is feasible at AHRI standard test conditions for residential HVAC equipment. When compared on a basis of primary energy input, performance equivalent to SEER 13 or 14 are theoretically attainable with this system.

TeGrotenhuis, Ward E.; Humble, Paul H.; Sweeney, J. B.

2012-05-01T23:59:59.000Z

419

Stabilization of High Efficiency CdTe Photovoltaic Modules in Controlled Indoor Light Soaking  

Science Conference Proceedings (OSTI)

The performance and stabilization of large-area, high-efficiency 9%, CdTe photovoltaic (PV) modules maintained under controlled light-soaking nominally at 800 Watts/m2 irradiance and 65C module temperature are investigated. Degradation of module performance occurs predominantly in the first few hundred hours of exposure under these conditions; these symptoms included losses in fill factor (FF), open-circuit voltage (Voc), and short-circuit current (Isc), which amount to between 7% and 15% total loss in performance. Higher stabilized performance was achieved with lower copper content in the back contact. Transient effects in module Voc and Isc were observed, suggesting partial annealing thereof when stored under low-light levels. Performance changes are analyzed, aided by monitoring the current-voltage characteristics in situ during exposure.

del Cueto, J. A.; Pruett, J.; Cunningham, D.

2003-05-01T23:59:59.000Z

420

Very High Efficiency Reactor (VHER) Concepts for Electrical Power Generation and Hydrogen Production  

DOE Green Energy (OSTI)

The goal of the Very High Efficiency Reactor study was to develop and analyze concepts for the next generation of nuclear power reactors. The next generation power reactor should be cost effective compared to current power generation plant, passively safe, and proliferation-resistant. High-temperature reactor systems allow higher electrical generating efficiencies and high-temperature process heat applications, such as thermo-chemical hydrogen production. The study focused on three concepts; one using molten salt coolant with a prismatic fuel-element geometry, the other two using high-pressure helium coolant with a prismatic fuel-element geometry and a fuel-pebble element design. Peak operating temperatures, passive-safety, decay heat removal, criticality, burnup, reactivity coefficients, and material issues were analyzed to determine the technical feasibility of each concept.

PARMA JR.,EDWARD J.; PICKARD,PAUL S.; SUO-ANTTILA,AHTI JORMA

2003-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "high-efficiency organic solar" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Demonstration of High Efficiency Elastocaloric Cooling with Large Delta- T Using NiTi Wires  

Science Conference Proceedings (OSTI)

Vapor compression (VC) is by far the most dominant technology for meeting all cooling and refrigeration needs around the world. It is a mature technology with the efficiency of modern compressors approaching the theoretical limit, but its envi-ronmental footprint remains a global problem. VC refrigerants such as hydrochlo-roflurocarbons (HCFCs) and hydrofluorocarbons (HFCs) are a significant source of green house gas (GHG) emissions, and their global warming potential (GWP) is as high as 1000 times that of CO2. It is expected that building space cooling and re-frigeration alone will amount to {approx} 5% of primary energy consumption and {approx}5% of all CO2 emission in U.S. in 2030 . As such, there is an urgent need to develop an al-ternative high-efficiency cooling technology that is affordable and environmentally friendly. Among the proposed candidates, magnetocaloric cooling (MC) is currently received a lot of attention because of its high efficiency. However, MC is inherently expensive because of the requirement of large magnetic field and rare earth materi-als. Here, we demonstrate an entirely new type of solid-state cooling mechanism based on the latent heat of reversible martensitic transformation. We call it elasto-caloric cooling (EC) after the superelastic transformation of austenite it utilizes. The solid-state refrigerant of EC is cost-effective, and it completely eliminates the use of any refrigerants including HCFCs/HFCs. We show that the COP (coefficient of per-formance) of a jugular EC with optimized materials can be as high as > 10 with measured {Delta}T of 17 C.

Cui, Jun; Wu, Yiming; Muehlbauer, Jan; Hwang, Yunho; Radermacher, Reinhard; Fackler, Sean; Wuttig, Manfred; Takeuchi, Ichiro

2012-08-01T23:59:59.000Z

422

DOE Solar Decathlon Coming to National Mall | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Solar Decathlon Coming to National Mall Solar Decathlon Coming to National Mall DOE Solar Decathlon Coming to National Mall October 1, 2009 - 12:00am Addthis WASHINGTON, DC - Early this morning, twenty university-led teams descended on the National Mall along with high-tech, high-efficiency solar-powered homes they have built for the 2009 U.S. Department of Energy Solar Decathlon. Over 800 student competitors from the United States, Canada, Spain and Germany will compete in the 2009 Solar Decathlon. The international competition takes place on the National Mall from October 8 -18 and will showcase high-efficiency, solar-powered homes that include the latest high-tech solutions and money-saving features. The overall winner will be announced on Friday, October 16. This is the fourth time DOE has

423

Next Generation Solar Cell Materials and Devices - Programmaster ...  

Science Conference Proceedings (OSTI)

Symposium, Next Generation Solar Cell Materials and Devices. Sponsorship. Organizer(s), Mark S. Goorsky, University of California, Los Angeles

424

Solar Power Beginner | Open Energy Information  

Open Energy Info (EERE)

Solar Power Beginner Solar Power Beginner Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Solar Power Beginner Agency/Company /Organization: Solar Power Beginner Sector: Energy Focus Area: Renewable Energy, Solar Topics: Resource assessment Website: www.solarpowerbeginner.com/index.html References: Solar Power Beginner[1] Solar Power Beginner is a website that specializes in providing simple solar information to people who are new to solar power. The site features information on photovoltaic panels[2], solar thermal energy[3], and everyday uses for solar power. Also included are interviews[4] with various experts in the solar industry. References ↑ "Solar Power Beginner" ↑ Solar Panels Page ↑ Solar Thermal Page ↑ Solar Interviews Page Retrieved from

425

DOE Solar Decathlon: Solar Decathlon Volunteer Roles  

NLE Websites -- All DOE Office Websites (Extended Search)

Already a Volunteer? Log In Volunteers work alongside U.S. Department of Energy Solar Decathlon 2013 and XPO organizers in a variety of roles. Learn more about these...

426

New, Cost-Competitive Solar Plants for Electric Utilities  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Amonix to develop its 7700 Amonix to develop its 7700 system, which drastically reduces the requirement for costly solar cells by using Fresnel lenses to concentrate sunlight 500 times onto small, highly efficient photovoltaic cells. This reduces the cell area so that expensive solar cell materials can be replaced with inexpensive plastic lenses. Amonix Inc. (Torrance, CA), founded in 1989, develops and

427

CRADA Final Report: Process development for hybrid solar cells  

Science Conference Proceedings (OSTI)

TCF funding of a CRADA between LBNL and RSLE leveraged RSLE's original $1M investment in LBNL research and led to development of a solar cell fabrication process that will bring the high efficiency, high voltage hybrid tandem solar cell closer to commercialization. RSLE has already built a pilot line at its Phoenix, Arizona site.

Ager, Joel W

2011-02-14T23:59:59.000Z

428

SBM Solar | Open Energy Information  

Open Energy Info (EERE)

SBM Solar SBM Solar Jump to: navigation, search Name SBM Solar Place North Carolina Sector Solar Product SBM Solar is a solar panel manufacturer based in North Carolina. References SBM Solar[1] LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! This article is a stub. You can help OpenEI by expanding it. SBM Solar is a company located in North Carolina . References ↑ "SBM Solar" Retrieved from "http://en.openei.org/w/index.php?title=SBM_Solar&oldid=350649" Categories: Clean Energy Organizations Companies Organizations Stubs What links here Related changes Special pages Printable version Permanent link Browse properties 429 Throttled (bot load) Error 429 Throttled (bot load) Throttled (bot load) Guru Meditation: XID: 2084745150

429

NEW OPTIMAL HIGH EFFICIENCY DSP-BASED DIGITAL CONTROLLER DESIGN FOR SUPER HIGH-SPEED PERMANENT  

E-Print Network (OSTI)

MAGNET SYNCHRONOUS MOTOR by LIMEI ZHAO A dissertation submitted in partial fulfillment magnet synchronous motors (PMSM). The PMSMs are a key component for the miniaturic cryocooler and the Florida Solar Energy Center. Advanced motor design methods, control strategies, and rapid progress

Wu, Shin-Tson

430

Modeling and Simulation of Solar PV Arrays under Changing Illumination Conditions  

E-Print Network (OSTI)

from the solar cell. PV has widespread use in niche markets such as consumer electronics, remote area onto a small number of highly efficient solar cells. PV systems mounted on house roofs can be used. Hybrid PV/thermal micro concentrator systems on building roofs are being developed to provide solar PV

Lehman, Brad

431

Current and lattice matched tandem solar cell  

DOE Patents (OSTI)

A multijunction (cascade) tandem photovoltaic solar cell device is fabricated of a Ga.sub.x In.sub.1-x P (0.505.ltoreq.X.ltoreq.0.515) top cell semiconductor lattice matched to a GaAs bottom cell semiconductor at a low-resistance heterojunction, preferably a p+/n+ heterojunction between the cells. The top and bottom cells are both lattice matched and current matched for high efficiency solar radiation conversion to electrical energy.

Olson, Jerry M. (Lakewood, CO)

1987-01-01T23:59:59.000Z

432

ORGANIC PHOTOVOLTAIC DEVICE OPTIMIZATION .  

E-Print Network (OSTI)

??Polymer based organic photovoltaic (OPV) is making great progress on solar cell performance in the past decade. As a potential alternative to conventional expensive photovoltaic… (more)

Nie, Wanyi

2012-01-01T23:59:59.000Z

433

Research on stable, high-efficiency, large-area amorphous silicon based modules -- Task B  

DOE Green Energy (OSTI)

This report documents progress in developing a stable, high- efficiency, four-terminal hybrid tandem module. The module consists of a semi-transparent, thin-film silicon:hydrogen alloy (TFS) top circuit and a copper indium diselenide (CuInSe{sub 2}) bottom circuit. Film deposition and patterning processes were successfully extended to 0.4-m{sup 2} substrates. A 33.2-W (8.4% efficient) module with a 3970-cm{sup 2} aperture area and a white back reflector was demonstrated; without the back reflector, the module produced 30.2 W (7.6% efficient). Placing a laminated, 31.6-W, 8.1%-efficient CuInSe{sub 2} module underneath this TFS module, with an air gap between the two, produces 11.2 W (2.9% efficient) over a 3883-cm{sup 2} aperture area. Therefore, the four-terminal tandem power output is 41.4 W, translating to a 10.5% aperture-area efficiency. Subsequently, a 37.8-W (9.7% aperture-area efficiency) CuInSe{sub 2} module was demonstrated with a 3905-cm{sup 2} aperture area. Future performances of single-junction and tandem modules of this size were modeled, and predicted power outputs exceed 50 W (13% efficient) for CuInSe{sub 2} and 65 W (17% efficient) for TFS/CuInSe{sub 2} tandem modules.

Mitchell, K.W.; Willet, D.R. (Siemens Solar Industries, Camarillo, CA (USA))

1990-10-01T23:59:59.000Z

434

Implications of Low Particulate Matter Emissions on System Fuel Efficiency for High Efficiency Clean Combustion  

DOE Green Energy (OSTI)

Advanced diesel combustion regimes such as High Efficiency Clean Combustion (HECC) offer the benefits of reduced engine out NOX and particulate matter (PM) emissions. Lower PM emissions during advanced combustion reduce the demand on diesel particulate filters (DPFs) and can, thereby, reduce the fuel penalty associated with DPF regeneration. In this study, a SiC DPF was loaded and regenerated on a 1.7-liter 4-cylinder diesel engine operated in conventional and advanced combustion modes at different speed and load conditions. A diesel oxidation catalyst (DOC) and a lean NOX trap (LNT) were also installed in the exhaust stream. Five steady-state speed and load conditions were weighted to estimate Federal Test Procedure (FTP) fuel efficiency. The DPF was loaded using lean-rich cycling with frequencies that resulted in similar levels of NOX emissions downstream of the LNT. The pressure drop across the DPF was measured at a standard point (1500 rpm, 5.0 bar) before and after loading, and a P rise rate was determined for comparison between conventional and advanced combustion modes. Higher PM emissions in conventional combustion resulted in a higher rate of backpressure rise across the DPF at all of the load points leading to more frequent DPF regenerations and higher fuel penalty. The fuel penalty during conventional combustion was 4.2% compared with 3.1% for a mixture of conventional and advanced modes.

Parks, II, James E [ORNL; Prikhodko, Vitaly Y [ORNL

2009-01-01T23:59:59.000Z

435

Development of High Efficiency Carbon Dioxide Commercial Heat Pump Water Heater  

Science Conference Proceedings (OSTI)

Although heat pump water heaters are today widely accepted in both Japan and Europe, where energy costs are high and government incentives for their use exist, acceptance of such products in the US has been limited. While this trend is slowly changing with the introduction of heat pump water heaters into the residential market, but acceptance remains low in the commercial sector. The objective of the presented work is the development of a high efficiency R744 heat pump water heater for commercial applications with effective utilization of the cooling capability for air conditioning and/or refrigeration. The ultimate goal is to achieve total system COP of up to 8. This unit will be targeted at commercial use where some cooling load is typically needed year round, such as restaurants, hotels, nursing homes, and hospitals. This paper presents the performance results from the development of four R744 commercial heat pump water heater packages of approximately 35 kW and comparison to a commercially available baseline R134a unit of the same capacity and footprint. In addition, the influences of an internal heat exchanger and an enhanced evaporator on the system performance are described and recommendations are made for further improvements of the R744 system.

Michael PETERSEN; Chad D. BOWERS; Stefan ELBEL; Pega HRNJAK

2012-07-01T23:59:59.000Z

436

Mobile Source Air Toxics (MSATs) from High Efficiency Clean Combustion: Catalytic Exhaust Treatment Effects  

Science Conference Proceedings (OSTI)

High Efficiency Clean Combustion (HECC) strategies such as homogenous charge compression ignition (HCCI) and pre-mixed charge compression ignition (PCCI) offer much promise for the reduction of NOx and PM from diesel engines. While delivering low PM and low NOx, these combustion modes often produce much higher levels of CO and HC than conventional diesel combustion modes. In addition, partially oxygenated species such as formaldehyde (an MSAT) and other aldehydes increase with HECC modes. The higher levels of CO and HCs have the potential to compromise the performance of the catalytic aftertreatment, specifically at low load operating points. As HECC strategies become incorporated into vehicle calibrations, manufacturers need to avoid producing MSATs in higher quantities than found in conventional combustion modes. This paper describes research on two different HECC strategies, HCCI and PCCI. Engine-out data for several MSAT species (formaldehyde, acetaldehyde, benzene, toluene, ethylbenzene, xylenes, naphthalene, PAHs, diesel PM) as well as other HC species are presented and compared when possible with conventional operation. In addition, catalyst-out values were measured to assess the destruction of individual MSATs over the catalyst. At low engine loads, MSATs were higher and catalyst performance was poorer. Particle sizing results identify large differences between PM from conventional and HECC operation.

Storey, John Morse [ORNL; Lewis Sr, Samuel Arthur [ORNL; Parks, II, James E [ORNL; Barone, Teresa L [ORNL; Prikhodko, Vitaly Y [ORNL

2008-01-01T23:59:59.000Z

437

High-efficiency dc electromagnetic pumps and flow couplers for LMFBRs. Final report  

SciTech Connect

The objective for the study reported here was to evaluate high efficiency direct current electromagnetic pump concepts for use in pool-type liquid metal cooled fast breeder reactors. It was concluded that the conventional direct current pump would not be practical for the high flow rates required, primarily because of the adverse high-current low-voltage supply requirements. However, a relatively new concept - the flow coupler - appears to be much more promising. In this concept, the primary and intermediate fluid flows are linked magnetically - with the intermediate fluid acting as a generator of the current that is used in a pump to drive the primary fluid. In this way the requirement for an external direct current supply and associated busbars is eliminated. Techniques to analyze such flow couplers have been developed and show that overall efficiencies in excess of 60% are attainable in relatively small volumes (3.5m in length, 2.5m in dia). This may permit a reduction in the size of the reactor vessel. Several flow coupler concepts are described which require further evaluation.

McNab, I.R.; Alexion, C.C.

1981-01-01T23:59:59.000Z

438

Generic closed control loop of a high efficiency low volume bioethanol distillery.  

E-Print Network (OSTI)

??Bioethanol is a type of biofuel that is created by fermenting organic materials into a solution called mash. This mash contains water, dead yeast cells,… (more)

Pearson, Andrew

2012-01-01T23:59:59.000Z

439

SolarHub | Open Energy Information  

Open Energy Info (EERE)

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