National Library of Energy BETA

Sample records for high efficiency solar

  1. High efficiency, radiation-hard solar cells

    E-Print Network [OSTI]

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

    2004-01-01

    Igari, and W. Warta, “Solar Cell Efficiency Tables (Version56326 High efficiency, radiation-hard solar cells Finalprototype high efficiency multijunction (MJ) solar cells use

  2. High-Efficiency Solar Cogeneration with Thermophotovoltaic &...

    Office of Environmental Management (EM)

    High-Efficiency Solar Cogeneration with Thermophotovoltaic & Fiber-Optic Daylighting High-Efficiency Solar Cogeneration with Thermophotovoltaic & Fiber-Optic Daylighting Credit:...

  3. Webinar: Highly Efficient Solar Thermochemical Reaction Systems

    Broader source: Energy.gov [DOE]

    Video recording and text version of the Fuel Cell Technologies Office webinar titled "Highly Efficient Solar Thermochemical Reaction Systems," originally presented on January 13, 2015.

  4. Webinar: Highly Efficient Solar Thermochemical Reaction Systems

    Broader source: Energy.gov [DOE]

    The Fuel Cell Technologies Office will present a live webinar titled "Highly Efficient Solar Thermochemical Reaction Systems" on Tuesday, January 13, from 12:00 to 1:00 p.m. Eastern Standard Time.

  5. Highly Efficient Solar Thermochemical Reaction Systems

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Highly Efficient, Solar Thermochemical Reaction Systems (2014 R&D 100 Award Winner) U.S. Department of Energy Fuel Cell Technologies Office 2 Question and Answer * Please type your...

  6. High efficiency, radiation-hard solar cells

    E-Print Network [OSTI]

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

    2004-01-01

    efficiency multijunction (MJ) solar cells use componentsin current multijunction (MJ) solar cells (GaAs and GaInP)

  7. Integrated Solar Thermochemical Reaction System for High Efficiency...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Integrated Solar Thermochemical Reaction System for High Efficiency Production of Electricity Integrated Solar Thermochemical Reaction System for High Efficiency Production of...

  8. High-Efficiency Solar Cogeneration with Thermophotovoltaic &...

    Broader source: Energy.gov (indexed) [DOE]

    targeted 'Solar Cogeneration' technologies to maximize energy generation & energy efficiency from the building's solar insolation resources. Project presents a novel, low-cost...

  9. High Efficiency Solar Integrated Roof Membrane Product

    SciTech Connect (OSTI)

    Partyka, Eric; Shenoy, Anil

    2013-05-15

    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.

  10. High-Temperature High-Efficiency Solar Thermoelectric Generators

    SciTech Connect (OSTI)

    Baranowski, LL; Warren, EL; Toberer, ES

    2014-03-01

    Inspired by recent high-efficiency thermoelectric modules, we consider thermoelectrics for terrestrial applications in concentrated solar thermoelectric generators (STEGs). The STEG is modeled as two subsystems: a TEG, and a solar absorber that efficiently captures the concentrated sunlight and limits radiative losses from the system. The TEG subsystem is modeled using thermoelectric compatibility theory; this model does not constrain the material properties to be constant with temperature. Considering a three-stage TEG based on current record modules, this model suggests that 18% efficiency could be experimentally expected with a temperature gradient of 1000A degrees C to 100A degrees C. Achieving 15% overall STEG efficiency thus requires an absorber efficiency above 85%, and we consider two methods to achieve this: solar-selective absorbers and thermally insulating cavities. When the TEG and absorber subsystem models are combined, we expect that the STEG modeled here could achieve 15% efficiency with optical concentration between 250 and 300 suns.

  11. High efficiency, radiation-hard solar cells

    SciTech Connect (OSTI)

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

    2004-10-22

    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.

  12. Highly efficient light management for perovskite solar cells

    E-Print Network [OSTI]

    Wang, Dong-Lin; Hou, Guo-Jiao; Zhu, Zhen-Gang; Yan, Qing-Bo; Su, Gang

    2015-01-01

    Organic-inorganic halide perovskite solar cells have enormous potential to impact the existing photovoltaic industry. As realizing a higher conversion efficiency of the solar cell is still the most crucial task, a great number of schemes were proposed to minimize the carrier loss by optimizing the electrical properties of the perovskite solar cells. Here, we focus on another significant aspect that is to minimize the light loss by optimizing the light management to gain a high efficiency for perovskite solar cells. In our scheme, the slotted and inverted prism structured SiO2 layers are adopted to trap more light into the solar cells, and a better transparent conducting oxide layer is employed to reduce the parasitic absorption. For such an implementation, the efficiency and the serviceable angle of the perovskite solar cell can be promoted impressively. This proposal would shed new light on developing the high-performance perovskite solar cells.

  13. Solar Energy Materials & Solar Cells 90 (2006) 34073415 High-efficiency flexible CdTe solar cells

    E-Print Network [OSTI]

    Romeo, Alessandro

    2006-01-01

    Solar Energy Materials & Solar Cells 90 (2006) 3407­3415 High-efficiency flexible CdTe solar cells: Solar cells; Thin films; CdTe; Flexible solar cells; Space solar cells; Solar energy ARTICLE IN PRESS for Renewable Energy Systems and Technology), Department of Electronic and Electrical Engineering, Loughborough

  14. High efficiency, radiation-hard solar cells

    E-Print Network [OSTI]

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

    2004-01-01

    M. , “III-V compound multi-junction solar cells: present andand fabricating multi-junction solar cells using a singleanalysis of multi-junction space solar cells,” Nuc. Instrum.

  15. Emerging High-Efficiency Low-Cost Solar Cell Technologies

    E-Print Network [OSTI]

    McGehee, Michael

    J. of Photovoltaics, 2 (2012) p. 303. Si GaAs #12;Why thin film GaAs;Gallium Arsenide · The 1.4 eV band gap is ideal for solar cells. · High quality films are grownEmerging High-Efficiency Low-Cost Solar Cell Technologies Mike McGehee Materials Science

  16. High Efficiency Solar Fuels Reactor Concept

    Broader source: Energy.gov [DOE]

    This presentation was delivered at the SunShot Concentrating Solar Power (CSP) Program Review 2013, held April 23–25, 2013 near Phoenix, Arizona.

  17. Solar Cells, 3 (1981) 337 -340 337 HIGH EFFICIENCY BIFACIAL BACK SURFACE FIELD SOLAR CELLS

    E-Print Network [OSTI]

    del Alamo, Jesús A.

    1981-01-01

    . CUEVAS, A. LUQUE, J. EGUREN and J. DEL ALAMO Instituto de Energia Solar, Escuela Tdcnica Superior deSolar Cells, 3 (1981) 337 - 340 337 HIGH EFFICIENCY BIFACIAL BACK SURFACE FIELD SOLAR CELLS A solar cells are presented. Effi- ciencies of 15.7% and 13.6% were measured under front and back air mass

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

    SciTech Connect (OSTI)

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

    2005-01-01

    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.

  19. High Efficiency Solar Power via Separated Photo and Voltaic Pathways

    SciTech Connect (OSTI)

    Michael J. Naughton

    2009-02-17

    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.

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

    E-Print Network [OSTI]

    Deng, Xunming

    1 High Efficiency and High Rate Deposited Amorphous Silicon-Based Solar Cells PHASE II Annual-Efficiency Single-Junction a-SiGe Solar Cells Section 3 Optimization of High-efficiency a-Si Top Cell Section 4. Figure 2-3 J-V curve of a single-junction a-SiGe solar cell with initial, active-area efficiency

  1. High-efficiency solar cell and method for fabrication

    DOE Patents [OSTI]

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

    1999-01-01

    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).

  2. High-efficiency solar cell and method for fabrication

    DOE Patents [OSTI]

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

    1999-08-31

    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.

  3. Highly Efficient Solar Thermochemical Reaction Systems

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:FinancingPetroleum12,ExecutiveFinancingR Walls - Building America Topa HighHigher|Energy

  4. Sterically Engineered Perylene Dyes for High Efficiency Oriented Fluorophore Luminescent Solar Concentrators

    E-Print Network [OSTI]

    Patrick, David L.

    Sterically Engineered Perylene Dyes for High Efficiency Oriented Fluorophore Luminescent Solar Luminescent solar concentrators (LSCs) collect and concentrate sunlight for use in solar power generation.1 or interior lighting, increasing the combined-cycle efficiency. Accordingly, LSC performance is expressed

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

    SciTech Connect (OSTI)

    2012-01-11

    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.

  6. Modelling and fabrication of high-efficiency silicon solar cells

    SciTech Connect (OSTI)

    Rohatgi, A.; Smith, A.W.; Salami, J.

    1991-10-01

    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.

  7. Air-Stable High-Efficiency Solar Cells Using Improved Single-Walled Carbon Nanotube Films

    E-Print Network [OSTI]

    Maruyama, Shigeo

    1 Air-Stable High-Efficiency Solar Cells Using Improved Single-Walled Carbon Nanotube Films Kehang intensities. The high efficiency and stability demonstrated in this study make SWNT/Si solar cell very front contact KEYWORDS: Single-walled carbon nanotube, solar cell, high efficiency, stability, SWNT

  8. Webinar January 13: Highly Efficient Solar Thermochemical Reaction...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    efficiency, converting methane and water into syngas-a mix of hydrogen and carbon monoxide-and the technology received an R&D 100 Award in 2014. As the solar energy is stored...

  9. Processes for producing low cost, high efficiency silicon solar cells

    DOE Patents [OSTI]

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

    1996-01-01

    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.

  10. ORIGINAL ARTICLE Highly efficient GaAs solar cells by limiting light emission

    E-Print Network [OSTI]

    Polman, Albert

    a non-concentrating system with limited emission angle in a thin, light trapping GaAs solar cellORIGINAL ARTICLE Highly efficient GaAs solar cells by limiting light emission angle Emily D Kosten1 of a high-quality GaAs solar cell is a feasible route to achieving power conversion efficiencies above 38

  11. High Excitation Transfer Efficiency from Energy Relay Dyes in Dye-Sensitized Solar Cells

    E-Print Network [OSTI]

    McGehee, Michael

    High Excitation Transfer Efficiency from Energy Relay Dyes in Dye-Sensitized Solar Cells Brian E soluble energy relay dyes with high molar extinction coefficients. KEYWORDS Solar cell, energy transfer-sensitized solar cells, the excited ERDs must be able to efficiently transfer energy to the sensitizing dyes

  12. Advanced Nanomaterials for High-Efficiency Solar Cells

    SciTech Connect (OSTI)

    Chen, Junhong

    2013-11-29

    Energy supply has arguably become one of the most important problems facing humankind. The exponential demand for energy is evidenced by dwindling fossil fuel supplies and record-high oil and gas prices due to global population growth and economic development. This energy shortage has significant implications to the future of our society, in addition to the greenhouse gas emission burden due to consumption of fossil fuels. Solar energy seems to be the most viable choice to meet our clean energy demand given its large scale and clean/renewable nature. However, existing methods to convert sun light into electricity are not efficient enough to become a practical alternative to fossil fuels. This DOE project aims to develop advanced hybrid nanomaterials consisting of semiconductor nanoparticles (quantum dots or QDs) supported on graphene for cost-effective solar cells with improved conversion efficiency for harvesting abundant, renewable, clean solar energy to relieve our global energy challenge. Expected outcomes of the project include new methods for low-cost manufacturing of hybrid nanostructures, systematic understanding of their properties that can be tailored for desired applications, and novel photovoltaic cells. Through this project, we have successfully synthesized a number of novel nanomaterials, including vertically-oriented graphene (VG) sheets, three-dimensional (3D) carbon nanostructures comprising few-layer graphene (FLG) sheets inherently connected with CNTs through sp{sup 2} carbons, crumpled graphene (CG)-nanocrystal hybrids, CdSe nanoparticles (NPs), CdS NPs, nanohybrids of metal nitride decorated on nitrogen-doped graphene (NG), QD-carbon nanotube (CNT) and QD-VG-CNT structures, TiO{sub 2}-CdS NPs, and reduced graphene oxide (RGO)-SnO{sub 2} NPs. We further assembled CdSe NPs onto graphene sheets and investigated physical and electronic interactions between CdSe NPs and the graphene. Finally we have demonstrated various applications of these nanomaterials in solar cells (both as photoanodes and counter electrodes), gas sensors, and energy storage devices. This research is potentially transformative since the availability of affordable hybrid nanostructures and their fundamental properties will enable various innovative applications of the multifunctional hybrid nanostructures and thus will accelerate new discoveries and inventions in nanoscience and nanotechnology.

  13. Processes for producing low cost, high efficiency silicon solar cells

    DOE Patents [OSTI]

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

    1998-06-16

    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.

  14. Processes for producing low cost, high efficiency silicon solar cells

    DOE Patents [OSTI]

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

    1998-06-16

    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.

  15. High-Efficiency Low-Cost Solar Receiver for Use in a Supercritical...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Low-Cost Solar Receiver for Use in a Supercritical CO2 Recompression Cycle - FY13 Q1 High-Efficiency Low-Cost Solar Receiver for Use in a Supercritical CO2 Recompression Cycle -...

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

    SciTech Connect (OSTI)

    Not Available

    2011-05-01

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

  17. EARTH ABUNDANT MATERIALS FOR HIGH EFFICIENCY HETEROJUNCTION THIN FILM SOLAR CELLS

    E-Print Network [OSTI]

    Ceder, Gerbrand

    materials for thin film solar cells such as CdTe and CIGS suffer from concerns over resource scarcity (eEARTH ABUNDANT MATERIALS FOR HIGH EFFICIENCY HETEROJUNCTION THIN FILM SOLAR CELLS Yun Seog Lee 1 conversion efficiencies should be increased. In terms of reducing module cost, thin film solar cells

  18. Design and Analysis of a High-Efficiency, Cost-Effective Solar Concentrator John H. Reif

    E-Print Network [OSTI]

    Reif, John H.

    1 Design and Analysis of a High-Efficiency, Cost-Effective Solar Concentrator John H. Reif, Kingdom of Saudi Arabia wsalhalabi@kau.edu.sa Abstract Solar concentrating systems are optical systems that concentrate solar energy for conversion into usable energy. Ideally, a solar concentrating system should have

  19. Design and global optimization of high-efficiency solar thermal systems

    E-Print Network [OSTI]

    .5298) Photonic crystals; (350.6050) Solar energy. References and links 1. W. Spirkl and H. Ries, "Solar. Harder and P. Wurfel, "Theoretical limits of thermophotovoltaic solar energy conversion," Semicond. SciDesign and global optimization of high-efficiency solar thermal systems with tungsten cermets David

  20. High-Efficiency Solar Cells for Large-Scale Electricity Generation

    SciTech Connect (OSTI)

    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.

    2008-09-26

    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.

  1. A highly efficient (>6%) Cd1xMnxSe quantum dot sensitized solar cell

    E-Print Network [OSTI]

    Cao, Guozhong

    , suffer from high cost of manufacturing and installation. Now the focus is on next generation solar cellsA highly efficient (>6%) Cd1ÀxMnxSe quantum dot sensitized solar cell Jianjun Tian,*a Lili Lv,a Chengbin Fei,b Yajie Wang,b Xiaoguang Liua and Guozhong Cao*bc Quantum dot sensitized solar cells (QDSCs

  2. innovati nNREL Produces Highly Efficient, Wide-Bandgap, Thin-Film Solar Cells

    E-Print Network [OSTI]

    CIGS solar cells. Their use of the high-temperature glass, designed by SCHOTT AG, allows higher fabrication temperatures, opening the door to new CIGS solar cells employing light-absorbing materials are plentiful. In contrast, CIGS solar cells with wide bandgaps can function at higher efficiencies regardless

  3. High-efficiency ion-implanted silicon solar cells

    SciTech Connect (OSTI)

    Spitzer, M.B.; Tobin, S.P.

    1984-05-01

    The development of solar cells with AM1 coversion efficiency of 18 percent is reported. The cells comprise an n/sup +/-p-p/sup +/ structure fabricated from float zone silicon having resistivity of 0.3 ..cap omega.. cm. The n/sup +/ and p/sup +/ regions are formed by low energy ion implantation and thermal annealing. An important feature of cell fabrication is the growth of SiO/sub 2/ passivation for reduction of surface recombination velocity. Details of both cell fabrication and testing are reported.

  4. ORIGINAL ARTICLE Highly efficient GaAs solar cells by limiting light emission

    E-Print Network [OSTI]

    Atwater, Harry

    ORIGINAL ARTICLE Highly efficient GaAs solar cells by limiting light emission angle Emily D Kosten1. This isotropic emission corresponds to a significant entropy increase in the solar cell, with a corresponding drop in efficiency. Here, using a detailed balance model, we show that limiting the emission angle

  5. Power efficiency for very high temperature solar thermal cavity receivers

    DOE Patents [OSTI]

    McDougal, Allan R. (LaCanada-Flintridge, CA); Hale, Robert R. (Upland, CA)

    1984-01-01

    This invention is an improved solar energy cavity receiver for exposing materials and components to high temperatures. The receiver includes a housing having an internal reflective surface defining a cavity and having an inlet for admitting solar radiation thereto. A photothermal absorber is positioned in the cavity to receive radiation from the inlet. A reflective baffle is positioned between the absorber and the inlet to severely restrict the re-radiation of energy through the inlet. The front surface of the baffle defines a narrow annulus with the internal reflective surface of the housing. The front surface of the baffle is contoured to reflect incoming radiation onto the internal surface of the housing, from which it is reflected through the annulus and onto the front surface of the absorber. The back surface of the baffle intercepts infrared radiation from the front of the absorber. With this arrangement, a high percentage of the solar power input is retained in the cavity; thus, high internal temperatures are attained.

  6. Quantum Dot Solar Cells: High Efficiency through Multiple Exciton Generation

    SciTech Connect (OSTI)

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

    2005-01-01

    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.

  7. ENI Renewable and Non-conventional Energy Prize 2012 High-efficiency solar cells based on nanophotonic design

    E-Print Network [OSTI]

    Polman, Albert

    demonstrated ultra-thin silicon solar cells on glass, world-record efficiency thin-film GaAs solar cells to solar cell design are applicable to other solar cell technologies as well, including thin-film CuInSe2ENI Renewable and Non-conventional Energy Prize 2012 High-efficiency solar cells based

  8. High Efficiency Thin Film CdTe and a-Si Based Solar Cells Annual Technical Report for the Period

    E-Print Network [OSTI]

    Deng, Xunming

    High Efficiency Thin Film CdTe and a-Si Based Solar Cells Annual Technical Report for the Period This report covers the second year 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. The effort on CdTe- based materials

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

    E-Print Network [OSTI]

    Hsu, W. Chuck

    2012-01-01

    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 ...

  10. High Efficiency CdTe Ink-Based Solar Cells Using Nanocrystals (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2015-01-01

    This NREL Highlight is being developed for the 2015 February Alliance S&T Board meeting and describes a solution-processable ink to produce high-efficiency solar cells using low temperature and simple processing.

  11. Formation of Porous Layers by Electrochemical Etching of Germanium and Gallium Arsenide for Cleave Engineered Layer Transfer (CELT) Application in High Efficiency Multi-Junction Solar Cells

    E-Print Network [OSTI]

    Fong, David Michael

    2012-01-01

    Application in High Efficiency Multi-Junction Solar Cells AApplication in High Efficiency Multi-Junction Solar Cells Bycost of high efficiency multi-junction solar cells through a

  12. High temperature performance of high-efficiency, multi-layer solar selective coatings for tower applications

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gray, M. H.; Tirawat, R.; Kessinger, K. A.; Ndione, P. F.

    2015-05-01

    The roadmap to next-generation concentrating solar power plants anticipates a progression to central towers with operating temperatures in excess of 650°C. These higher temperatures are required to drive higher power-cycle efficiencies, resulting in lower cost energy. However, these conditions also place a greater burden on the materials making up the receiver. Any novel absorber material developed for next-generation receivers must be stable in air, cost effective, and survive thousands of heating and cooling cycles. The collection efficiency of a power tower plant can be increased if the energy absorbed by the receiver is maximized while the heat loss from themore »receiver to the environment is minimized. Thermal radiation losses can be significant (>7% annual energy loss) with receivers at temperatures above 650°C. We present progress toward highly efficient and durable solar selective absorbers (SSAs) intended for operating temperatures from 650°C to 1000°C. Selective efficiency (?sel) is defined as the energy retained by the absorber, accounting for both absorptance and emittance, relative to the energy incident on the surface. The low emittance layers of multilayer SSAs are binary compounds of refractory metals whose material properties indicate that coatings formed of these materials should be oxidation resistant in air to 800-1200°C. On this basis, we initially developed a solar selective coating for parabolic troughs. This development has been successfully extended to meet the absorptance and emittance objectives for the more demanding, high temperature regime. We show advancement in coating materials, processing and designs resulting in the initial attainment of target efficiencies ?sel > 0.91 for proposed tower conditions. Additionally, spectral measurements show that these coatings continue to perform at targeted levels after cycling to temperatures of 1000°C in environments of nitrogen and forming gas.« less

  13. High temperature performance of high-efficiency, multi-layer solar selective coatings for tower applications

    SciTech Connect (OSTI)

    Gray, M. H.; Tirawat, R.; Kessinger, K. A.; Ndione, P. F.

    2015-05-01

    The roadmap to next-generation concentrating solar power plants anticipates a progression to central towers with operating temperatures in excess of 650°C. These higher temperatures are required to drive higher power-cycle efficiencies, resulting in lower cost energy. However, these conditions also place a greater burden on the materials making up the receiver. Any novel absorber material developed for next-generation receivers must be stable in air, cost effective, and survive thousands of heating and cooling cycles. The collection efficiency of a power tower plant can be increased if the energy absorbed by the receiver is maximized while the heat loss from the receiver to the environment is minimized. Thermal radiation losses can be significant (>7% annual energy loss) with receivers at temperatures above 650°C. We present progress toward highly efficient and durable solar selective absorbers (SSAs) intended for operating temperatures from 650°C to 1000°C. Selective efficiency (?sel) is defined as the energy retained by the absorber, accounting for both absorptance and emittance, relative to the energy incident on the surface. The low emittance layers of multilayer SSAs are binary compounds of refractory metals whose material properties indicate that coatings formed of these materials should be oxidation resistant in air to 800-1200°C. On this basis, we initially developed a solar selective coating for parabolic troughs. This development has been successfully extended to meet the absorptance and emittance objectives for the more demanding, high temperature regime. We show advancement in coating materials, processing and designs resulting in the initial attainment of target efficiencies ?sel > 0.91 for proposed tower conditions. Additionally, spectral measurements show that these coatings continue to perform at targeted levels after cycling to temperatures of 1000°C in environments of nitrogen and forming gas.

  14. Solion ion source for high-efficiency, high-throughput solar cell manufacturing

    SciTech Connect (OSTI)

    Koo, John Binns, Brant; Miller, Timothy; Krause, Stephen; Skinner, Wesley; Mullin, James

    2014-02-15

    In this paper, we introduce the Solion ion source for high-throughput solar cell doping. As the source power is increased to enable higher throughput, negative effects degrade the lifetime of the plasma chamber and the extraction electrodes. In order to improve efficiency, we have explored a wide range of electron energies and determined the conditions which best suit production. To extend the lifetime of the source we have developed an in situ cleaning method using only existing hardware. With these combinations, source life-times of >200 h for phosphorous and >100 h for boron ion beams have been achieved while maintaining 1100 cell-per-hour production.

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

    SciTech Connect (OSTI)

    Antoniadis, H.

    2011-03-01

    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.

  16. Design for the fabrication of high efficiency solar cells

    DOE Patents [OSTI]

    Simmons, Joseph H. (Gainesville, FL)

    1998-01-01

    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.

  17. Numerical simulation: Toward the design of high-efficiency planar perovskite solar cells

    SciTech Connect (OSTI)

    Liu, Feng; Zhu, Jun E-mail: sydai@ipp.ac.cn; Wei, Junfeng; Li, Yi; Lv, Mei; Yang, Shangfeng; Zhang, Bing; Yao, Jianxi; Dai, Songyuan E-mail: sydai@ipp.ac.cn

    2014-06-23

    Organo-metal halide perovskite solar cells based on planar architecture have been reported to achieve remarkably high power conversion efficiency (PCE, >16%), rendering them highly competitive to the conventional silicon based solar cells. A thorough understanding of the role of each component in solar cells and their effects as a whole is still required for further improvement in PCE. In this work, the planar heterojunction-based perovskite solar cells were simulated with the program AMPS (analysis of microelectronic and photonic structures)-1D. Simulation results revealed a great dependence of PCE on the thickness and defect density of the perovskite layer. Meanwhile, parameters including the work function of the back contact as well as the hole mobility and acceptor density in hole transport materials were identified to significantly influence the performance of the device. Strikingly, an efficiency over 20% was obtained under the moderate simulation conditions.

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

    SciTech Connect (OSTI)

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

    2000-05-01

    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.

  19. High Efficiency Multiple-Junction Solar Cells - Energy Innovation Portal

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverse (Journalvivo Low-DoseOptionsthroughput spectrometer forInnovationandSolar

  20. HIGH EFFICIENCY CdTe/CdS THIN FILM SOLAR CELLS WITH A NOVEL BACK-CONTACT Nicola Romeoa

    E-Print Network [OSTI]

    Romeo, Alessandro

    HIGH EFFICIENCY CdTe/CdS THIN FILM SOLAR CELLS WITH A NOVEL BACK-CONTACT Nicola Romeoa , Alessio in the fabrication of high efficiency CdTe/CdS thin film solar cells. Usually, it is done first by etching the CdTe/CdS structure causing shunt paths by segregating into the grain boundaries or lowering the cell efficiency

  1. In an effort to design a more low cost, highly efficient alternative to the traditional silicon solar cell, our

    E-Print Network [OSTI]

    In an effort to design a more low cost, highly efficient alternative to the traditional silicon solar cell, our research implements lead sulfide nanocrystals as light harvesters. Semiconducting

  2. Current-matched high-efficiency, multijunction monolithic solar cells

    DOE Patents [OSTI]

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

    1993-01-01

    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

  3. Numerical analysis for high-efficiency GaAs solar cells fabricated on Si substrates

    SciTech Connect (OSTI)

    Yamaguchi, M.; Amano, C.; Itoh, Y.

    1989-07-15

    This paper describes some recent developments in GaAs thin-film solar cells fabricated on Si substrates by metalorganic chemical vapor deposition and numerically analyzes them.GaAs solar cells with efficiency of more than 18% are successfully fabricated on Si substrates by reducing the dislocation density. Photovoltaic properties of GaAs/Si cells are analyzed by considering the effect of nonuniform dislocation distribution on recombination properties of GaAs thin films on Si substrates. Numerical analysis shows that the effect of majority-carrier trapping must be considered. High efficiency GaAs solar cells with total-area efficiency of over 20% on Si substrates can be realized if dislocation density can be reduced to less than 5/times/10/sup 5/ cm/sup /minus/2/.

  4. HIGH EFFICIENCY Cu(ln,Ga)SepBASED SOLAR CELLS: PROCESSING OF NOVEL ABSORBER STRUCTURES

    E-Print Network [OSTI]

    Scofield, John H.

    HIGH EFFICIENCY Cu(ln,Ga)SepBASED SOLAR CELLS: PROCESSING OF NOVEL ABSORBER STRUCTURES Miguel A conditions (ASTM E892-87, Global 1000 W/m'). The first attempts to translate this development to larger areas a device performance point of view. In terms of lightweight flexible substrate-for potential space

  5. High Efficiency Nanostructured III-V Photovoltaics for Solar Concentrator Application

    SciTech Connect (OSTI)

    Hubbard, Seth

    2012-09-12

    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.

  6. Highly Efficient Solar Thermochemical Reaction Systems | Department of

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:Financing Tool Fits the Bill Financing ToolSustainableSecurityHighDepartmentEnergy

  7. Highly Efficient Multigap Solar Cell Materials - Energy Innovation Portal

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverse (JournalvivoHigh energyHighland View school Highland

  8. Amorphous silicon/crystalline silicon heterojunctions: The future of high-efficiency silicon solar cells

    E-Print Network [OSTI]

    Firestone, Jeremy

    ;5 Record efficiencies #12;6 Diffused-junction solar cells Diffused-junction solar cell Chemical passivation to ~650 mV #12;7 Silicon heterojunction solar cells a-Si:H provides excellent passivation of c-Si surface Heterojunction solar cell Chemical passivation Chemical passivation #12;8 Voc and silicon heterojunction solar

  9. Formation of Porous Layers by Electrochemical Etching of Germanium and Gallium Arsenide for Cleave Engineered Layer Transfer (CELT) Application in High Efficiency Multi-Junction Solar Cells

    E-Print Network [OSTI]

    Fong, David Michael

    2012-01-01

    Efficiency Multi-Junction Solar Cells A thesis submitted inHigh Efficiency Multi-Junction Solar Cells By David Michaelsubstrate costs of multi-junction solar cells by recycling

  10. High-Efficiency GaInP/GaAs Tandem Solar Cells

    SciTech Connect (OSTI)

    Bertness, K. A.; Friedman, D. J.; Kurtz, S. R.; Kibbler, A. E.; Cramer, C.; Olson, J. M.

    1996-09-01

    GaInP/GaAs tandem solar cells have achieved efficiencies between 25.7-30.2%, depending on illumination conditions. The efficiencies are the highest confirmed two-terminal values measured for any solar cell within each standard illumination category. The monolithic, series-connected design of the tandem cells allows them to be substituted for silicon or gallium arsenide cells in photovoltaic panel systems with minimal design changes. The advantages of using GaInP/GaAs tandem solar cells in space and terrestrial applications are discussed primarily in terms of the reduction in balance-of-system costs that accrues when using a higher efficiency cell. The new efficiency values represent a significant improvement over previous efficiencies for this materials system, and we identify grid design, back interface passivation, and top interface passivation as the three key factors leading to this improvement. In producing the high-efficiency cells, we have addressed nondestructive diagnostics and materials growth reproducibility as well as peak cell performance.

  11. High-efficiency GaInP/GaAs tandem solar cells

    SciTech Connect (OSTI)

    Bertness, K.A.; Friedman, D.J.; Kurtz, S.R.; Kibbler, A.E.; Kramer, C.; Olson, J.M.

    1994-12-01

    GaInP/GaAs tandem solar cells have achieved new record efficiencies, specifically 25.7% under air-mass 0 (AM0) illumination, 29.5% under AM 1.5 global (AM1.5G) illumination, and 30.2% at 140-180x concentration under AM 1.5 direct (AM1.5D) illumination. These values are the highest two-terminal efficiencies achieved by any solar cell under these illumination conditions. The monolithic, series-connected design of the tandem cells allows them to be substituted for silicon or gallium arsenide cells in photovoltaic panel systems with minimal design changes. The advantages of using GaInP/GaAs tandem solar cells in space and terrestrial applications are discussed primarily in terms of the reduction in balance-of-system costs that accrues when using a higher efficiency cell. The new efficiency values represent a significant improvement over previous efficiencies for this materials system, and we identify grid design, back interface passivation, and top interface passivation as the three key factors leading to this improvement. In producing the high-efficiency cells, we have addressed nondestructive diagnostics and materials growth reproducibility as well as peak cell performance. 31 refs.

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

    SciTech Connect (OSTI)

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

    2012-06-11

    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.

  13. HIGH EFFICIENCY AMORPHOUS SILICON GERMANIUM SOLAR CELLS X. Liao, W. Du, X. Yang, H. Povolny, X. Xiang and X. Deng

    E-Print Network [OSTI]

    Deng, Xunming

    -SiGe) alloy has been widely used as narrow bandgap i-layers in multi-junction a-Si based solar cells [1, 2HIGH EFFICIENCY AMORPHOUS SILICON GERMANIUM SOLAR CELLS X. Liao, W. Du, X. Yang, H. Povolny, X ABSTRACT We report high-efficiency single-junction a-SiGe n-i-p solar cells deposited using rf PECVD

  14. High Efficiency Thin Film CdTe and a-Si Based Solar Cells Final Technical Report for the Period

    E-Print Network [OSTI]

    Deng, Xunming

    High Efficiency Thin Film CdTe and a-Si Based Solar Cells Final Technical Report for the PeriodTe-based thin-film solar cells and on high efficiency a-Si-based thin-film solar cells. Phases I and II have-SiGe bottom cells. · Studied the sputter deposition of ITO films for the top electrode on a-Si cells and found

  15. Bifacial Si Heterojunction-Perovskite Organic-Inorganic Tandem to Produce Highly Efficient Solar Cell

    E-Print Network [OSTI]

    Asadpour, Reza; Khan, M Ryyan; Alam, Muhammad A

    2015-01-01

    As single junction thin-film technologies, both Si heterojunction (HIT) and Perovskite based solar cells promise high efficiencies at low cost. One expects that a tandem cell design with these cells connected in series will improve the efficiency further. Using a self-consistent numerical modeling of optical and transport characteristics, however, we find that a traditional series connected tandem design suffers from low Jsc due to band-gap mismatch and current matching constraints. It requires careful thickness optimization of Perovskite to achieve any noticeable efficiency gain. Specifically, a traditional tandem cell with state-of-the-art HIT (24%) and Perovskite (20%) sub-cells provides only a modest tandem efficiency of ~25%. Instead, we demonstrate that a bifacial HIT/Perovskite tandem design decouples the optoelectronic constraints and provides an innovative path for extraordinary efficiencies. In the bifacial configuration, the same state-of the-art sub-cells achieve a normalized output of 33%, exceed...

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

    E-Print Network [OSTI]

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

    2013-01-01

    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.

  17. Highly efficient inverted organic solar cells using amino acid modified indium tin oxide as cathode

    SciTech Connect (OSTI)

    Li, Aiyuan; Nie, Riming; Deng, Xianyu; Wei, Huaixin; Li, Yanqing; Tang, Jianxin; Zheng, Shizhao; Wong, King-Young

    2014-03-24

    In this paper, we report that highly efficient inverted organic solar cells were achieved by modifying the surface of indium tin oxide (ITO) using an amino acid, Serine (Ser). With the modification of the ITO surface, device efficiency was significantly enhanced from 0.63% to 4.17%, accompanied with an open circuit voltage (Voc) that was enhanced from 0.30?V to 0.55?V. Ultraviolet and X-ray photoelectron spectroscopy studies indicate that the work function reduction induced by the amino acid modification resulting in the decreased barrier height at the ITO/organic interface played a crucial role in the enhanced performances.

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

    E-Print Network [OSTI]

    Deng, Xunming

    of narrow bandgap a-SiGe and µc-SiGe films deposited using different hydrogen dilution Section 3 Triple-junction a-Si Solar Cells with Heavily Doped Thin Interface Layers at the Tunnel Junctions Section 4 High 3-1 I-V performance of triple cell having heavily doped tunnel-junction interface layers

  19. High bandwidth-efficiency solar-blind AlGaN Schottky photodiodes with low dark current

    E-Print Network [OSTI]

    High bandwidth-efficiency solar-blind AlGaN Schottky photodiodes with low dark current T. Tut a , N.38Ga0.62N/GaN heterojunction solar-blind Schottky photodetectors with low dark current, high responsivity, and fast pulse response were demonstrated. A five-step microwave compatible fabrication process

  20. High Efficiency Solar-based Catalytic Structure for CO{sub 2} Reforming

    SciTech Connect (OSTI)

    Menkara, Hisham

    2013-09-30

    Throughout this project, we developed and optimized various photocatalyst structures for CO{sub 2} reforming into hydrocarbon fuels and various commodity chemical products. We also built several closed-loop and continuous fixed-bed photocatalytic reactor system prototypes for a larger-scale demonstration of CO{sub 2} reforming into hydrocarbons, mainly methane and formic acid. The results achieved have indicated that with each type of reactor and structure, high reforming yields can be obtained by refining the structural and operational conditions of the reactor, as well as by using various sacrificial agents (hole scavengers). We have also demonstrated, for the first time, that an aqueous solution containing acid whey (a common bio waste) is a highly effective hole scavenger for a solar-based photocatalytic reactor system and can help reform CO{sub 2} into several products at once. The optimization tasks performed throughout the project have resulted in efficiency increase in our conventional reactors from an initial 0.02% to about 0.25%, which is 10X higher than our original project goal. When acid whey was used as a sacrificial agent, the achieved energy efficiency for formic acid alone was ~0.4%, which is 16X that of our original project goal and higher than anything ever reported for a solar-based photocatalytic reactor. Therefore, by carefully selecting sacrificial agents, it should be possible to reach energy efficiency in the range of the photosynthetic efficiency of typical crop and biofuel plants (1-3%).

  1. Response to "Comment on `Towards high efficiency thin-film crystalline silicon solar cells: The roles of light trapping and non-radiative recombinations'" [J. Appl. Phys. 117,

    E-Print Network [OSTI]

    Response to "Comment on `Towards high efficiency thin-film crystalline silicon solar cells high efficiency thin-film crystalline silicon solar cells: The roles of light trapping and non.1063/1.4905182 Towards high efficiency thin-film crystalline silicon solar cells: The roles of light trapping and non

  2. Ultrathin, high-efficiency, broad-band, omni-acceptance, organic solar cells enhanced by

    E-Print Network [OSTI]

    : Three of central challenges in solar cells are high light coupling into solar cell, high light trapping electrode, and in-between a polymer photovoltaic active layer (P3HT/PCBM) of 85 nm thick (1/3 average

  3. Towards high efficiency thin-film crystalline silicon solar cells: The roles of light trapping and non-radiative recombinations

    E-Print Network [OSTI]

    important evaluation criterion for photovoltaic (PV) technology. Therefore, research on novel structuresTowards high efficiency thin-film crystalline silicon solar cells: The roles of light trapping February 2014; published online 3 March 2014) Thin-film solar cells based on silicon have emerged

  4. Study of a-SiGe:H films and nip devices used in high efficiency triple junction solar cells

    E-Print Network [OSTI]

    Deng, Xunming

    -layers in multi-junction amorphous silicon based solar cells [1]. The advantage is that by varying the amountStudy of a-SiGe:H films and n­i­p devices used in high efficiency triple junction solar cells and n­i­p solar cells for GeH4=Si2H6 ratio varying from 1.43 to 0. This results in a variation of band

  5. High-efficiency GaAs solar cells grown by molecular-beam epitaxy

    SciTech Connect (OSTI)

    Melloch, M.R. (School of Electrical Engineering, Purdue University, West Lafayette, Indiana 47907 (USA)); Tobin, S.P. (Spire Corporation, Patriots Park, Bedford, Massachusetts 01730 (USA)); Stellwag, T.B. (School of Electrical Engineering, Purdue University, West Lafayette, Indiana 47907 (USA)); Bajgar, C. (Spire Corporation, Patriots Park, Bedford, Massachusetts 01730 (USA)); Keshavarzi, A.; Lundstrom, M.S. (School of Electrical Engineering, Purdue University, West Lafayette, Indiana 47907 (USA)); Emery, K. (Solar Energy Research Institute, Golden, Colorado 80401 (USA))

    1990-03-01

    Previously, solar cells fabricated from molecular-beam epitaxually (MBE)-grown material have been inferior in performance to those fabricated from metalorganic chemical vapor deposited (MOCVD) material. We have obtained 1-sun air mass (AM) 1.5 efficiencies of 23.8% for 0.25 cm{sup 2} GaAs solar cells fabricated on MBE-grown material. This is the first solar cell fabricated on MBE material which is of comparable performance to solar cells fabricated on MOCVD material. Details of the MBE system preparation and film growth procedure along with a detailed evaluation of the solar cells will be presented.

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

    SciTech Connect (OSTI)

    Carmody, M.; Gilmore, A.

    2011-05-01

    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.

  7. Bifacial Si Heterojunction-Perovskite Organic-Inorganic Tandem to Produce Highly Efficient Solar Cell

    E-Print Network [OSTI]

    Reza Asadpour; Raghu V. K. Chavali; M. Ryyan Khan; Muhammad A. Alam

    2015-05-15

    As single junction thin-film technologies, both Si heterojunction (HIT) and Perovskite based solar cells promise high efficiencies at low cost. One expects that a tandem cell design with these cells connected in series will improve the efficiency further. Using a self-consistent numerical modeling of optical and transport characteristics, however, we find that a traditional series connected tandem design suffers from low Jsc due to band-gap mismatch and current matching constraints. It requires careful thickness optimization of Perovskite to achieve any noticeable efficiency gain. Specifically, a traditional tandem cell with state-of-the-art HIT (24%) and Perovskite (20%) sub-cells provides only a modest tandem efficiency of ~25%. Instead, we demonstrate that a bifacial HIT/Perovskite tandem design decouples the optoelectronic constraints and provides an innovative path for extraordinary efficiencies. In the bifacial configuration, the same state-of the-art sub-cells achieve a normalized output of 33%, exceeding the bifacial HIT performance at practical albedo reflections. Unlike the traditional design, this bifacial design is relatively insensitive to Perovskite thickness variations, which may translate to simpler manufacture and higher yield.

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

    E-Print Network [OSTI]

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

    2008-01-01

    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 ...

  9. Thin silicon foils produced by epoxy-induced spalling of silicon for high efficiency solar cells

    SciTech Connect (OSTI)

    Martini, R., E-mail: roberto.martini@imec.be [Department of Electrical Engineering, KU Leuven, Kasteelpark 10, 3001 Leuven (Belgium); imec, Kapeldreef 75, 3001 Leuven (Belgium); Kepa, J.; Stesmans, A. [Department of Physics, KU Leuven, Celestijnenlaan 200 D, 3001 Leuven (Belgium); Debucquoy, M.; Depauw, V.; Gonzalez, M.; Gordon, I. [imec, Kapeldreef 75, 3001 Leuven (Belgium); Poortmans, J. [Department of Electrical Engineering, KU Leuven, Kasteelpark 10, 3001 Leuven (Belgium); imec, Kapeldreef 75, 3001 Leuven (Belgium); Universiteit Hasselt, Martelarenlaan 42, B-3500 Hasselt (Belgium)

    2014-10-27

    We report on the drastic improvement of the quality of thin silicon foils produced by epoxy-induced spalling. In the past, researchers have proposed to fabricate silicon foils by spalling silicon substrates with different stress-inducing materials to manufacture thin silicon solar cells. However, the reported values of effective minority carrier lifetime of the fabricated foils remained always limited to ?100??s or below. In this work, we investigate epoxy-induced exfoliated foils by electron spin resonance to analyze the limiting factors of the minority carrier lifetime. These measurements highlight the presence of disordered dangling bonds and dislocation-like defects generated by the exfoliation process. A solution to remove these defects compatible with the process flow to fabricate solar cells is proposed. After etching off less than 1??m of material, the lifetime of the foil increases by more than a factor of 4.5, reaching a value of 461??s. This corresponds to a lower limit of the diffusion length of more than 7 times the foil thickness. Regions with different lifetime correlate well with the roughness of the crack surface which suggests that the lifetime is now limited by the quality of the passivation of rough surfaces. The reported values of the minority carrier lifetime show a potential for high efficiency (>22%) thin silicon solar cells.

  10. High throughput parallel backside contacting and periodic texturing for high-efficiency solar cells

    DOE Patents [OSTI]

    Daniel, Claus; Blue, Craig A.; Ott, Ronald D.

    2014-08-19

    Disclosed are configurations of long-range ordered features of solar cell materials, and methods for forming same. Some features include electrical access openings through a backing layer to a photovoltaic material in the solar cell. Some features include textured features disposed adjacent a surface of a solar cell material. Typically the long-range ordered features are formed by ablating the solar cell material with a laser interference pattern from at least two laser beams.

  11. Thermodynamics, Entropy, Information and the Efficiency of Solar Cells

    E-Print Network [OSTI]

    Abrams, Zeev R.

    2012-01-01

    reciprocity of solar energy conversion. Physica E 14, 71 (94. P. Würfel, Solar energy conversion with hot electronsHigh-Efficiency Solar Energy Conversion Through Flux

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

    SciTech Connect (OSTI)

    Not Available

    2012-09-01

    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.'

  13. Incorporating photon recycling into the analytical drift-diffusion model of high efficiency solar cells

    SciTech Connect (OSTI)

    Lumb, Matthew P.; Steiner, Myles A.; Geisz, John F.; Walters, Robert J.

    2014-11-21

    The analytical drift-diffusion formalism is able to accurately simulate a wide range of solar cell architectures and was recently extended to include those with back surface reflectors. However, as solar cells approach the limits of material quality, photon recycling effects become increasingly important in predicting the behavior of these cells. In particular, the minority carrier diffusion length is significantly affected by the photon recycling, with consequences for the solar cell performance. In this paper, we outline an approach to account for photon recycling in the analytical Hovel model and compare analytical model predictions to GaAs-based experimental devices operating close to the fundamental efficiency limit.

  14. Solar ADEPT: Efficient Solar Energy Systems

    SciTech Connect (OSTI)

    2011-01-01

    Solar ADEPT Project: The 7 projects that make up ARPA-E's Solar ADEPT program, short for 'Solar Agile Delivery of Electrical Power Technology,' aim to improve the performance of photovoltaic (PV) solar energy systems, which convert the sun's rays into electricity. Solar ADEPT projects are integrating advanced electrical components into PV systems to make the process of converting solar energy to electricity more efficient.

  15. Efficient solar cooling: first ever non-tracking solar collectors powering a double effect absorption chiller

    E-Print Network [OSTI]

    Poiry, Heather Marie

    2011-01-01

    A. and Winston, R. (1980) “Solar collectors for low and49: Delta T of the solar collectors during an efficiencyHigh-temperature, Solar Collectors for Mass Production.

  16. Layer-By-Layer Self-Assembly of CIGS Nanoparticles and Polymers for All-Solution Processable Low-Cost, High-Efficiency Solar Cells

    E-Print Network [OSTI]

    Zhou, Yaoqi

    -Cost, High-Efficiency Solar Cells Tung Ho1 , Robert Vittoe3 , Namratha Kakumanu2 , Sudhir Shrestha2-Purdue University Indianapolis (IUPUI), Indianapolis, IN 46202 Thin film solar cells made from copper indium gallium thereby affecting solar cell efficiency. This research aims to study various polymer materials to replace

  17. Influence of perimeter recombination on high-efficiency GaAs p/n heteroface solar cells

    SciTech Connect (OSTI)

    De Moulin, P.D.; Lundstrom, M.S.; Carpenter, M.S.; Melloch, M.R. (School of Electrical Engineering, Purdue Univ., West Lafayette, IN (US)); Tobin, S.P. (Spire Corp., Bedford, MA (US))

    1988-08-01

    Perimeter recombination currents have been characterized for 0.5 x 0.5- and 2 x 2-cm/sup 2/ p/n GaAs solar cells. Measurements show that perimeter recombination dominates the n = 2 dark current component of these high-efficiency solar cells. The results also suggest that perimeter recombination will be substantial even in much larger area solar cells. Although little influence on open-circuit voltage is expected, perimeter recombination may adversely affect the cell's one-sun fill factor. Because of its importance to one-sun applications, recombination at the junction perimeter must be suppressed before GaAs solar cells approach their limiting conversion efficiencies.

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

    E-Print Network [OSTI]

    Armstrong, Paul Barber

    2010-01-01

    50% improvement in solar cell efficiency. The synthesis of asignificantly higher solar cell efficiencies relative tofor obtaining high efficiency solar cells. According to

  19. The role of Förster Resonance Energy Transfer in luminescent solar concentrator efficiency and color tunability

    E-Print Network [OSTI]

    Balaban, Benjamin

    2013-01-01

    IN LUMINESCENT SOLAR CONCENTRATOR EFFICIENCY AND COLORM.A. Baldo, "High-efficiency organic solar concentrators forin luminescent solar concentrator efficiency and color

  20. ATOMIC-LAYER-DEPOSITED ALUMINUM OXIDE FOR THE SURFACE PASSIVATION OF HIGH-EFFICIENCY SILICON SOLAR CELLS

    E-Print Network [OSTI]

    ATOMIC-LAYER-DEPOSITED ALUMINUM OXIDE FOR THE SURFACE PASSIVATION OF HIGH-EFFICIENCY SILICON SOLAR- contacted rear being either passivated by atomic-layer- deposited Al2O3 or by stacks consisting-Si passivation to thermal processes. ATOMIC-LAYER-DEPOSITED Al2O3 Recently, it was shown that thin films

  1. DEVELOPMENT OF HIGH EFFICIENCY FLEXIBLE CdTe SOLAR CELLS A.Romeo, M. Arnold, D.L. Btzner, H. Zogg and A.N. Tiwari*

    E-Print Network [OSTI]

    Romeo, Alessandro

    applications that require a very high specific power (ratio of output electrical power to the solar module specific power is an important issue for space solar cells: if satellites are lighter they are easierDEVELOPMENT OF HIGH EFFICIENCY FLEXIBLE CdTe SOLAR CELLS A.Romeo, M. Arnold, D.L. Bätzner, H. Zogg

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

    SciTech Connect (OSTI)

    None

    2010-01-01

    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.

  3. Highly efficient organic multi-junction solar cells with a thiophene based donor material

    SciTech Connect (OSTI)

    Meerheim, Rico Körner, Christian; Leo, Karl

    2014-08-11

    The efficiency of organic solar cells can be increased by serial stacked subcells even upon using the same absorber material. For the multi-junction devices presented here, we use the small molecule donor material DCV5T-Me. The subcell currents were matched by optical transfer matrix simulation, allowing an efficiency increase from 8.3% for a single junction up to 9.7% for a triple junction cell. The external quantum efficiency of the subcells, measured under appropriate light bias illumination, is spectrally shifted due to the microcavity of the complete stack, resulting in a broadband response and an increased cell current. The increase of the power conversion efficiency upon device stacking is even stronger for large area cells due to higher influence of the resistance of the indium tin oxide anode, emphasizing the advantage of multi-junction devices for large-area applications.

  4. High-efficiency GaAs/Ge monolithic tandem solar cells

    SciTech Connect (OSTI)

    Tobin, S.P.; Vernon, S.M.; Bajgar, C.; Haven, V.E.; Geoffroy, L.M.; Lillington, D.R.

    1988-05-01

    High photovoltaic efficiency and light weight are important criteria for spacecraft power applications. Present GaAs cells are approaching their efficiency limits, but are not efficient or light enough for future needs. The authors have investigated tandem cells of GaAs grown by MOCVD on thin Ge to address both higher efficiency and reduced weight. GaAs/Ge monolithic tandem cells of 4-cm/sup 2/ area have been produced with independently verified efficiencies up to 21.7 percent (AMO, one sun, 25/sup 0/C, total area). Under AM1.5 Global conditions, efficiencies are up to 24.3 percent. These are the highest one-sun efficiencies reported for GaAs/Ge cells, and the highest efficiency for a two-terminal monolithic tandem cell.

  5. New strategy to promote conversion efficiency using high-index nanostructures in thin-film solar cells

    E-Print Network [OSTI]

    Wang, DongLin

    2014-01-01

    Nano-scaled metallic or dielectric structures may provide various ways to trap light into thin-film solar cells for improving the conversion efficiency. In most schemes, the textured active layers are involved into light trapping structures that can provide perfect optical benefits but also bring undesirable degradation of electrical performance. Here we propose a novel approach to design high-performance thin-film solar cells. In our strategy, a flat active layer is adopted for avoiding electrical degradation, and an optimization algorithm is applied to seek for an optimized light trapping structure for the best optical benefit. As an example, we show that the efficiency of a flat a-Si:H thin-film solar cell can be promoted close to the certified highest value. It is also pointed out that, by choosing appropriate dielectric materials with high refractive index (>3) and high transmissivity in wavelength region of 350nm-800nm, the conversion efficiency of solar cells can be further enhanced.

  6. Concentrating Solar Power: Efficiently Leveraging Equilibrium...

    Energy Savers [EERE]

    Concentrating Solar Power: Efficiently Leveraging Equilibrium Mechanisms for Engineering New Thermochemical Storage Concentrating Solar Power: Efficiently Leveraging Equilibrium...

  7. High efficiency multijunction amorphous silicon alloy-based solar cells and modules

    SciTech Connect (OSTI)

    Guha, S.; Yang, J.; Banerjeee, A.; Glatfelter, T.; Hoffman, K.; Xu, X. )

    1994-06-30

    We have achieved initial efficiency of 11.4% as confirmed by National Renewable Energy Laboratory (NREL) on a multijunction amorphous silicon alloy photovoltaic module of one-square-foot-area. [bold This] [bold is] [bold the] [bold highest] [bold initial] [bold efficiency] [bold confirmed] [bold by] [bold NREL] [bold for] [bold any] [bold thin] [bold film] [bold photovoltaic] [bold module]. After light soaking for 1000 hours at 50 [degree]C under one-sun illumination, a module with initial efficiency of 11.1% shows a stabilized efficiency of 9.5%. Key factors that led to this high performance are discussed.

  8. NANO REVIEW Enhancing Solar Cell Efficiencies through 1-D Nanostructures

    E-Print Network [OSTI]

    Chen, Junhong

    energy is not occurring due to the high cost and inadequate efficiencies of existing solar cells of solar energy is the high cost and inadequate efficiencies of existing solar cells. InnovationsNANO REVIEW Enhancing Solar Cell Efficiencies through 1-D Nanostructures Kehan Yu Æ Junhong Chen

  9. Evaluation of annual efficiencies of high temperature central receiver concentrated solar power plants with thermal energy storage.

    SciTech Connect (OSTI)

    Ehrhart, Brian David; Gill, David Dennis

    2013-07-01

    The current study has examined four cases of a central receiver concentrated solar power plant with thermal energy storage using the DELSOL and SOLERGY computer codes. The current state-of-the-art base case was compared with a theoretical high temperature case which was based on the scaling of some input parameters and the estimation of other parameters based on performance targets from the Department of Energy SunShot Initiative. This comparison was done for both current and high temperature cases in two configurations: a surround field with an external cylindrical receiver and a north field with a single cavity receiver. There is a fairly dramatic difference between the design point and annual average performance, especially in the solar field and receiver subsystems, and also in energy losses due to the thermal energy storage being full to capacity. Additionally, there are relatively small differences (<2%) in annual average efficiencies between the Base and High Temperature cases, despite an increase in thermal to electric conversion efficiency of over 8%. This is due the increased thermal losses at higher temperature and operational losses due to subsystem start-up and shut-down. Thermal energy storage can mitigate some of these losses by utilizing larger thermal energy storage to ensure that the electric power production system does not need to stop and re-start as often, but solar energy is inherently transient. Economic and cost considerations were not considered here, but will have a significant impact on solar thermal electric power production strategy and sizing.

  10. Mesoporous TiO2 beads for high efficiency CdS/ CdSe quantum dot co-sensitized solar cells

    E-Print Network [OSTI]

    Cao, Guozhong

    Mesoporous TiO2 beads for high efficiency CdS/ CdSe quantum dot co-sensitized solar cells Ru Zhou-sensitized solar cell (QDSC) application. The photoanode films were composed of submicrometer-sized beads consisting of packed TiO2 nanocrystallites. A power conversion efficiency up to 4.05% has been achieved

  11. Improving Solar-Cell Efficiency

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2003 | 2002 2001 | 2000 | 1998 | Subscribe to APS Science Highlights rss feed Improving Solar Cell Efficiency October 7, 2014 Bookmark and Share The two-dimensional grazing...

  12. Improved power efficiency for very-high-temperature solar-thermal-cavity receivers

    DOE Patents [OSTI]

    McDougal, A.R.; Hale, R.R.

    1982-04-14

    This invention is an improved solar energy cavity receiver for exposing materials and components to high temperatures. The receiver includes a housing having an internal reflective surface defining a cavity and having an inlet for admitting solar radiation thereto. A photothermal absorber is positiond in the cavity to receive radiation from the inlet. A reflective baffle is positioned between the absorber and the inlet to severely restrict the re-radiation of energy through the inlet. The front surface of the baffle defines a narrow annulus with the internal reflective surface of the housing. The front surface of the baffle is contoured to reflect incoming radiation onto the internal surface of the housing, from which it is reflected through the annulus and onto the front surface of the absorber. The back surface of the baffle intercepts radiation from the front of the absorber. With this arrangement, a high percentage of the solar power input is retained in the cavity; thus, high internal temperatues are attained.

  13. Performance and Loss Analyses of High-Efficiency CBD-ZnS/Cu(In1-xGax)Se2 Thin-Film Solar Cells

    E-Print Network [OSTI]

    Sites, James R.

    1 Performance and Loss Analyses of High-Efficiency CBD-ZnS/Cu(In1-xGax)Se2 Thin-Film Solar Cells, Setagaya-ku, Tokyo 157-8572, Japan (Received ) KEYWORDS: ZnS buffer, Cu(In,Ga)Se2, thin-film solar cells alternative to CdS in polycrystalline thin-film Cu(In1-xGax)Se2 (CIGS) solar cells. Cells with efficiency

  14. Where solar thermal meets photovoltaic for high-efficiency power conversion

    E-Print Network [OSTI]

    Bierman, David M. (David Matthew)

    2014-01-01

    To develop disruptive techniques which generate power from the Sun, one must understand the aspects of existing technologies that limit performance. Solar thermal and solar photovoltaic schemes dominate today's solar market ...

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

    SciTech Connect (OSTI)

    Vernon, S.M. )

    1993-04-01

    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.

  16. The goal of this work is to develop low cost and highly efficient hybrid solar cells based on semiconductor nanoparticles (NPs). Hybrid solar cells have been demonstrated to take advantages of both inorganic and

    E-Print Network [OSTI]

    The goal of this work is to develop low cost and highly efficient hybrid solar cells based on semiconductor nanoparticles (NPs). Hybrid solar cells have been demonstrated to take advantages of both to improve optical and electrical properties of photovoltaic devices. Hybrid solar cells having long-armed Cd

  17. Final Report: Tunable Narrow Band Gap Absorbers For Ultra High Efficiency Solar Cells

    SciTech Connect (OSTI)

    Bedair, Salah M.; Hauser, John R.; Elmasry, Nadia; Colter, Peter C.; Bradshaw, G.; Carlin, C. Z.; Samberg, J.; Edmonson, Kenneth

    2012-07-31

    We report on a joint research program between NCSU and Spectrolab to develop an upright multijunction solar cell structure with a potential efficiency exceeding the current record of 41.6% reported by Spectrolab. The record efficiency Ge/GaAs/InGaP triple junction cell structure is handicapped by the fact that the current generated by the Ge cell is much higher than that of both the middle and top cells. We carried out a modification of the record cell structure that will keep the lattice matched condition and allow better matching of the current generated by each cell. We used the concept of strain balanced strained layer superlattices (SLS), inserted in the i-layer, to reduce the bandgap of the middle cell without violating the desirable lattice matched condition. For the middle GaAs cell, we have demonstrated an n-GaAs/i-(InGaAs/GaAsP)/p-GaAs structure, where the InxGa1-xAs/GaAs1-yPy SLS is grown lattice matched to GaAs and with reduced bandgap from 1.43 eV to 1.2 eV, depending upon the values of x and y.

  18. Single-Walled Carbon Nanotubes and Graphene as Highly Efficient Hole Extraction and Transport Layer for Solar Cells

    E-Print Network [OSTI]

    Maruyama, Shigeo

    for Solar Cells Shigeo Maruyama, Kehang Cui, Takaaki Chiba, Xiao Chen, Rong Xiang, Shohei Chiashi Department in various kinds of solar cells [1-4]. We found out that three-dimensional honeycomb structured SWNTs was also demonstrated in perovskite solar cells [3] and organic solar cells [4] with high PCE. More

  19. High-Efficiency Solar Cogeneration with T-PV and Fiber Optic Daylighting

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:FinancingPetroleum12,ExecutiveFinancing ProgramsDepartmentHigh-Efficiency Parking Lighting||Joseph

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

    SciTech Connect (OSTI)

    Deng, X.

    2006-01-01

    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.

  1. 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

    SciTech Connect (OSTI)

    Ravi, T. S.

    2013-05-01

    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.

  2. Research on high-efficiency, multiple-gap, multijunction, amorphous-silicon-based alloy thin-film solar cells

    SciTech Connect (OSTI)

    Guha, S. )

    1989-06-01

    This report presents results of research on advancing our understanding of amorphous-silicon-based alloys and their use in small-area multijunction solar cells. The principal objectives of the program are to develop a broad scientific base for the chemical, structural, optical, and electronic properties of amorphous-silicon-based alloys; to determine the optimum properties of these alloy materials as they relate to high-efficiency cells; to determine the optimum device configuration for multijunction cells; and to demonstrate proof-of-concept, multijunction, a-Si-alloy-based solar cells with 18% efficiency under standard AM1.5 global insolation conditions and with an area of at least 1 cm{sup 2}. A major focus of the work done during this reporting period was the optimization of a novel, multiple-graded structure that enhances cell efficiency through band-gap profiling. The principles of the operation of devices incorporating such a structure, computer simulations of those, and experimental results for both single- and multijunction cells prepared by using the novel structure are discussed in detail. 14 refs., 35 figs., 7 tabs.

  3. Approaches To Integrating A HIgh Penertration Of Solar PV and CPV Onto The Electrical Grid

    E-Print Network [OSTI]

    Hill, Steven Craig

    2013-01-01

    Second, a solar cell's efficiency increases underproduce large-area, high-efficiency solar cells than it issystems [58]. Solar cell efficiencies can be dramatically

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

    E-Print Network [OSTI]

    Judkins, Zachara Steele

    2007-01-01

    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 ...

  5. Earth abundant materials for high efficiency heterojunction thin film solar cells

    E-Print Network [OSTI]

    Buonassisi, Tonio

    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 ...

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

    SciTech Connect (OSTI)

    Not Available

    2011-08-01

    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.

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

    SciTech Connect (OSTI)

    Not Available

    1984-01-01

    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.

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

    SciTech Connect (OSTI)

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

    2011-09-29

    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).

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

    SciTech Connect (OSTI)

    Yamaguchi, Masafumi; Bouzazi, Boussairi; Suzuki, Hidetoshi; Ikeda, Kazuma; Kojima, Nobuaki; Ohshita, Yoshio

    2012-10-06

    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.

  10. Formation of Porous Layers by Electrochemical Etching of Germanium and Gallium Arsenide for Cleave Engineered Layer Transfer (CELT) Application in High Efficiency Multi-Junction Solar Cells

    E-Print Network [OSTI]

    Fong, David Michael

    2012-01-01

    III! V Multijunction Solar Cells,” (2003). J. F. Geisz, etEfficiency Multi-Junction Solar Cells A thesis submitted inEfficiency Multi-Junction Solar Cells By David Michael Fong

  11. Ultrahigh Efficiency Multiband Solar Cells Final Report for Director's Innovation Initiative Project DII-2005-1221

    E-Print Network [OSTI]

    Ager III, Joel W.; Walukiewicz, W.; Yu, Kin Man

    2006-01-01

    Igari, and W. Warta, “Solar Cell Efficiency Tables (VersionGreen et al. , “Solar cell efficiency tables (version 25),”this design are used in high-efficiency solar panels used on

  12. Heteroepitaxial (Al)GaAs structures on Ge and Si for advanced high-efficiency solar cells

    SciTech Connect (OSTI)

    Vernon, S.M.; Spitzer, M.B.; Tobin, S.P.; Wolfson, R.G.

    1984-05-01

    The results of heteroepitaxial growth of GaAs and GaAlAs directly on Si are presented, and applications to new cell structures are suggested. The novel feature of this work is the elimination of a Ge lattice transition region. This feature not only reduces the cost of substrate preparation, but also makes possible the fabrication of high efficiency monolithic cascade structures. All films to be discussed were grown by organometallic chemical vapor deposition at atmospheric pressure. This process yielded reproducible, large-area films of GaAs, grown directly on Si, that are tightly adherent and smooth, and are characterized by a defect density of 5 X 10/sup 6/ cm/sup -2/. Preliminary studies indicate that GaAlAs can also be grown in this way. The use of a 20-layer superlattice to reduce dislocations was attempted, although in this experiment a Ge-coated Si substrate was utilized. Also presented are several low-cost and/or low-weight structures which make use of these heteroepitaxial layers in the construction of high-efficiency solar cells.

  13. High-efficiency Al sub 0. 22 Ga sub 0. 78 As solar cells grown by molecular beam epitaxy

    SciTech Connect (OSTI)

    Melloch, M.R. (School of Electrical Engineering, Purdue University, West Lafayette, Indiana 47907 (USA)); Tobin, S.P.; Bajgar, C. (Spire Corporation, Patriots Park, Bedford, MA (USA)); Keshavarzi, A.; Stellwag, T.B.; Lush, G.B.; Lundstrom, M.S. (School of Electrical Engineering, Purdue University, West Lafayette, IN (USA)); Emery, K. (Solar Energy Research Institute, Golden, CO (USA))

    1990-07-02

    The quality of {ital pn} junction photodetectors made of Al{sub 0.2}Ga{sub 0.8}As has been investigated as a first step in the optimization of tandem solar cells. We have obtained 1 sun AM1.5 efficiencies of 16.1% for 0.25 cm{sup 2} Al{sub 0.22}Ga{sub 0.78}As solar cells fabricated from molecular beam epitaxy (MBE) material. This efficiency is 3.2 percentage points higher than the previously best reported efficiency of 12.9% for an Al{sub 0.2}Ga{sub 0.8}As solar cell fabricated from MBE material.

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

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservationBio-Inspired Solar FuelTechnologyTel: Name: Rm.mountains"

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

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservationBio-Inspired Solar FuelTechnologyTel: Name: Rm.mountains"Cells The

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

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservationBio-Inspired Solar FuelTechnologyTel: Name: Rm.mountains"Cells

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

    SciTech Connect (OSTI)

    Walker, K.; Joslin, S.

    2011-05-01

    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.

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

    SciTech Connect (OSTI)

    Noufi, R.; Zweibel, K.

    2006-05-01

    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.

  19. An Unconventional Route to High-Efficiency Dye-Sensitized Solar Cells via Embedding Graphitic Thin Films into TiO2 Nanoparticle

    E-Print Network [OSTI]

    Lin, Zhiqun

    120-750, Korea School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States # Department of Materials Science and Engineering, Iowa State University production due to their high solar energy conversion efficiency as well as relatively low fabrication cost.1

  20. Forming high efficiency silicon solar cells using density-graded anti-reflection surfaces

    DOE Patents [OSTI]

    Yuan, Hao-Chih; Branz, Howard M.; Page, Matthew R.

    2014-09-09

    A method (50) is provided for processing a graded-density AR silicon surface (14) to provide effective surface passivation. The method (50) includes positioning a substrate or wafer (12) with a silicon surface (14) in a reaction or processing chamber (42). The silicon surface (14) has been processed (52) to be an AR surface with a density gradient or region of black silicon. The method (50) continues with heating (54) the chamber (42) to a high temperature for both doping and surface passivation. The method (50) includes forming (58), with a dopant-containing precursor in contact with the silicon surface (14) of the substrate (12), an emitter junction (16) proximate to the silicon surface (14) by doping the substrate (12). The method (50) further includes, while the chamber is maintained at the high or raised temperature, forming (62) a passivation layer (19) on the graded-density silicon anti-reflection surface (14).

  1. Forming high-efficiency silicon solar cells using density-graded anti-reflection surfaces

    DOE Patents [OSTI]

    Yuan, Hao-Chih; Branz, Howard M.; Page, Matthew R.

    2015-07-07

    A method (50) is provided for processing a graded-density AR silicon surface (14) to provide effective surface passivation. The method (50) includes positioning a substrate or wafer (12) with a silicon surface (14) in a reaction or processing chamber (42). The silicon surface (14) has been processed (52) to be an AR surface with a density gradient or region of black silicon. The method (50) continues with heating (54) the chamber (42) to a high temperature for both doping and surface passivation. The method (50) includes forming (58), with a dopant-containing precursor in contact with the silicon surface (14) of the substrate (12), an emitter junction (16) proximate to the silicon surface (14) by doping the substrate (12). The method (50) further includes, while the chamber is maintained at the high or raised temperature, forming (62) a passivation layer (19) on the graded-density silicon anti-reflection surface (14).

  2. High Efficiency CdTe/CdS Thin Film Solar Cells Prepared by Treating CdTe Films with a Freon Gas in Substitution of CdCl2

    E-Print Network [OSTI]

    Romeo, Alessandro

    High Efficiency CdTe/CdS Thin Film Solar Cells Prepared by Treating CdTe Films with a Freon Gas a sufficient conversion efficiency to be considered for an industrial application. The fabrication process observed. Solar cell efficiency obtained with this treatment, close to 16%, is comparable if not larger

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

    SciTech Connect (OSTI)

    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.

    2000-01-01

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

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

    SciTech Connect (OSTI)

    Guha, S.; Yang, J.

    2005-10-01

    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.

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

    SciTech Connect (OSTI)

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

    1999-07-01

    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.

  6. PERFORMANCE ANALYSIS OF A WINDOWED HIGH TEMPERATURE GAS RECEIVER USING A SUSPENSION OF ULTRAFINE CARBON PARTICLES AS THE SOLAR ABSORBER

    E-Print Network [OSTI]

    Fisk, William J.

    2012-01-01

    incident solar intensity on receiver efficiency and receiverA,J,, "The Efficiency of High Temperature Solar ReceiversThe efficiency increases with incident solar intensity but

  7. Light-induced V{sub oc} increase and decrease in high-efficiency amorphous silicon solar cells

    SciTech Connect (OSTI)

    Stuckelberger, M., E-mail: michael.stuckelberger@epfl.ch; Riesen, Y.; Despeisse, M.; Schüttauf, J.-W.; Haug, F.-J.; Ballif, C. [Ecole Polytechnique Fédérale de Lausanne (EPFL), Institute of Microengineering (IMT), Photovoltaics and Thin-Film Electronics Laboratory, Rue de la Maladière 71, CH-2000 Neuchâtel (Switzerland)

    2014-09-07

    High-efficiency amorphous silicon (a-Si:H) solar cells were deposited with different thicknesses of the p-type amorphous silicon carbide layer on substrates of varying roughness. We observed a light-induced open-circuit voltage (V{sub oc}) increase upon light soaking for thin p-layers, but a decrease for thick p-layers. Further, the V{sub oc} increase is enhanced with increasing substrate roughness. After correction of the p-layer thickness for the increased surface area of rough substrates, we can exclude varying the effective p-layer thickness as the cause of the substrate roughness dependence. Instead, we explain the observations by an increase of the dangling-bond density in both the p-layer—causing a V{sub oc} increase—and in the intrinsic absorber layer, causing a V{sub oc} decrease. We present a mechanism for the light-induced increase and decrease, justified by the investigation of light-induced changes of the p-layer and supported by Advanced Semiconductor Analysis simulation. We conclude that a shift of the electron quasi-Fermi level towards the conduction band is the reason for the observed V{sub oc} enhancements, and poor amorphous silicon quality on rough substrates enhances this effect.

  8. Correlating High Power Conversion Efficiency of PTB7:PC71BM Inverted Organic Solar Cells to Nanoscale Structure

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Das, Sanjib; Keum, Jong Kahk; Browning, Jim; Gu, Gong; Yang, Bin; Do, Changwoo; Chen, Wei; Chen, Jihua; Ivanov, Ilia N; Hong, Kunlun; et al

    2015-07-16

    Advances in materials design and device engineering led to inverted organic solar cells (i-OSCs) with superior power conversion efficiencies (PCEs) to their conventional counterparts, in addition to the well-known better ambient stability. Despite the significant progress, however, it has so far been unclear how the morphologies of the photoactive layer and its interface with the cathode modifying layer impact device performance. Here, we report an in-depth morphology study of the i-OSC active and cathode modifying layers, employing a model system with the well-established bulk-heterojunction, PTB7:PC71BM as the active layer and poly-[(9,9-bis(3 -(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] (PFN) as the cathode surface modifying layer. Wemore »have also identified the role of a processing additive, 1,8-diiodooctane (DIO), used in the spin-casting of the active layer to increase PCE. Using a variety of characterization techniques, we demonstrate that the high PCEs of i-OSCs are due to the smearing (diffusion) of electron-accepting PC71BM into the PFN layer, resulting in improved electron transport. The PC71BM diffusion occurs after spin-casting the active layer onto the PFN layer, when residual solvent molecules act as a plasticizer. The DIO additive, with a higher boiling point than the host solvent, has a longer residence time in the spin-cast active layer, resulting in more PC71BM smearing and therefore more efficient electron transport. This work provides important insight and guidance to further enhancement of i-OSC performance by materials and interface engineering.« less

  9. Correlating High Power Conversion Efficiency of PTB7:PC71BM Inverted Organic Solar Cells with Nanoscale Structures

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Das, Sanjib; Keum, Jong Kahk; Browning, Jim; Gu, Gong; Yang, Bin; Do, Changwoo; Chen, Wei; Chen, Jihua; Ivanov, Ilia N; Hong, Kunlun; et al

    2015-07-16

    Advances in materials design and device engineering led to inverted organic solar cells (i-OSCs) with superior power conversion efficiencies (PCEs) to their conventional counterparts, in addition to the well-known better ambient stability. Despite the significant progress, however, it has so far been unclear how the morphologies of the photoactive layer and its interface with the cathode modifying layer impact device performance. Here, we report an in-depth morphology study of the i-OSC active and cathode modifying layers, employing a model system with the well-established bulk-heterojunction, PTB7:PC71BM as the active layer and poly-[(9,9-bis(3 -(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] (PFN) as the cathode surface modifying layer. Wemore »have also identified the role of a processing additive, 1,8-diiodooctane (DIO), used in the spin-casting of the active layer to increase PCE. Using a variety of characterization techniques, we demonstrate that the high PCEs of i-OSCs are due to the smearing (diffusion) of electron-accepting PC71BM into the PFN layer, resulting in improved electron transport. The PC71BM diffusion occurs after spin-casting the active layer onto the PFN layer, when residual solvent molecules act as a plasticizer. The DIO additive, with a higher boiling point than the host solvent, has a longer residence time in the spin-cast active layer, resulting in more PC71BM smearing and therefore more efficient electron transport. This work provides important insight and guidance to further enhancement of i-OSC performance by materials and interface engineering.« less

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

    DOE Patents [OSTI]

    Sopori, Bhushan L. (Denver, CO)

    1999-01-01

    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.

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

    DOE Patents [OSTI]

    Sopori, B.L.

    1999-04-27

    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.

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

    DOE Patents [OSTI]

    Sopori, Bhushan L. (Denver, CO)

    2001-01-01

    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.

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

    SciTech Connect (OSTI)

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

    1999-09-16

    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.

  14. Berkeley Lab Sheds Light on Improving Solar Cell Efficiency

    E-Print Network [OSTI]

    Lawrence Berkeley National Laboratory

    2007-01-01

    light on improving solar cell efficiency Ernest Orlandomethods produce solar cells with an efficiency of 12-15%;

  15. Towards high efficiency thin-film crystalline silicon solar cells: The roles of light trapping and non-radiative recombinations

    SciTech Connect (OSTI)

    Bozzola, A. Kowalczewski, P.; Andreani, L. C.

    2014-03-07

    Thin-film solar cells based on silicon have emerged as an alternative to standard thick wafers technology, but they are less efficient, because of incomplete absorption of sunlight, and non-radiative recombinations. In this paper, we focus on the case of crystalline silicon (c-Si) devices, and we present a full analytic electro-optical model for p-n junction solar cells with Lambertian light trapping. This model is validated against numerical solutions of the drift-diffusion equations. We use this model to investigate the interplay between light trapping, and bulk and surface recombination. Special attention is paid to surface recombination processes, which become more important in thinner devices. These effects are further amplified due to the textures required for light trapping, which lead to increased surface area. We show that c-Si solar cells with thickness of a few microns can overcome 20% efficiency and outperform bulk ones when light trapping is implemented. The optimal device thickness in presence of light trapping, bulk and surface recombination, is quantified to be in the range of 10–80??m, depending on the bulk quality. These results hold, provided the effective surface recombination is kept below a critical level of the order of 100?cm/s. We discuss the possibility of meeting this requirement, in the context of state-of-the-art techniques for light trapping and surface passivation. We show that our predictions are within the capability of present day silicon technologies.

  16. INTERNAL QUANTUM EFFICIENCY OF BACK ILLUMINATED n+ pp+ SOLAR CELLS

    E-Print Network [OSTI]

    del Alamo, Jesús A.

    629 INTERNAL QUANTUM EFFICIENCY OF BACK ILLUMINATED n+ pp+ SOLAR CELLS A. LUQUE, J. EGUREN and J+ layer of the back illuminated n+ pp+ solar cells has been carried out, and compared, 1 1. Introduction. - High intensity silicon solar cells, illuminated on the surface opposite

  17. An easy-to-fabricate low-temperature TiO{sub 2} electron collection layer for high efficiency planar heterojunction perovskite solar cells

    SciTech Connect (OSTI)

    Conings, B.; Baeten, L.; Jacobs, T.; Dera, R.; D’Haen, J.; Manca, J.; Boyen, H.-G.

    2014-08-01

    Organometal trihalide perovskite solar cells arguably represent the most auspicious new photovoltaic technology so far, as they possess an astonishing combination of properties. The impressive and brisk advances achieved so far bring forth highly efficient and solution processable solar cells, holding great promise to grow into a mature technology that is ready to be embedded on a large scale. However, the vast majority of state-of-the-art perovskite solar cells contains a dense TiO{sub 2} electron collection layer that requires a high temperature treatment (>450?°C), which obstructs the road towards roll-to-roll processing on flexible foils that can withstand no more than ?150?°C. Furthermore, this high temperature treatment leads to an overall increased energy payback time and cumulative energy demand for this emerging photovoltaic technology. Here we present the implementation of an alternative TiO{sub 2} layer formed from an easily prepared nanoparticle dispersion, with annealing needs well within reach of roll-to-roll processing, making this technology also appealing from the energy payback aspect. Chemical and morphological analysis allows to understand and optimize the processing conditions of the TiO{sub 2} layer, finally resulting in a maximum obtained efficiency of 13.6% for a planar heterojunction solar cell within an ITO/TiO{sub 2}/CH{sub 3}NH{sub 3}PbI{sub 3-x}Cl{sub x}poly(3-hexylthiophene)/Ag architecture.

  18. High Throughput, Low Toxic Processing of Very Thin, High Efficiency CIGSS Solar Cells: Final Report, December 2008

    SciTech Connect (OSTI)

    Dhere, N. G.

    2009-04-01

    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.

  19. High efficiency and high concentration in photovoltaics

    SciTech Connect (OSTI)

    Yamaguchi, Masafumi; Luque, A.

    1999-10-01

    In this paper, the authors present the state-of-the-art of multijunction solar cells and the future prospects of this technology. Their use in terrestrial applications will likely be for concentrators operating at very high concentrations. Some trends are also discussed and the authors present a cost calculation showing that highly efficient cells under very high concentration would be able to produce electricity at costs competitive with electricity generation costs for some utilities.

  20. "Approaches to Ultrahigh Efficiency Solar Energy Conversion"...

    Office of Science (SC) Website

    "Approaches to Ultrahigh Efficiency Solar Energy Conversion" Webinar Energy Frontier Research Centers (EFRCs) EFRCs Home Centers Research Science Highlights News & Events EFRC News...

  1. Ames Lab 101: Improving Solar Cell Efficiency

    ScienceCinema (OSTI)

    Biswas, Rana

    2012-08-29

    Rana Biswas, a scientist with the Ames Laboratory, discusses his team's research in creating more efficient solar cells and working with Iowa Thin Film to produce these cells.

  2. DESIGN APPROACHES AND MATERIALS PROCESSES FOR ULTRAHIGH EFFICIENCY LATTICE MISMATCHED MULTI-JUNCTION SOLAR CELLS

    E-Print Network [OSTI]

    Atwater, Harry

    of the minority carrier lifetime. INTRODUCTION High efficiency triple junction solar cells have recently been heterostructures grown in a multi-junction solar cell-like structure by MOCVD. Initial solar cell data are also of the materials used in multi-junction solar cells must be optimized to efficiently absorb as much of the solar

  3. Nanofluid-based receivers for high-temperature, high-flux direct solar collectors

    E-Print Network [OSTI]

    Lenert, Andrej

    2010-01-01

    Solar power plants with surface receivers have low overall energy conversion efficiencies due to large emissive losses at high temperatures. Alternatively, volumetric receivers promise increased performance because solar ...

  4. Material requirements for the adoption of unconventional silicon crystal and wafer growth techniques for high-efficiency solar cells

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Hofstetter, Jasmin; del Cañizo, Carlos; Wagner, Hannes; Castellanos, Sergio; Buonassisi, Tonio

    2015-10-15

    Silicon wafers comprise approximately 40% of crystalline silicon module cost and represent an area of great technological innovation potential. Paradoxically, unconventional wafer-growth techniques have thus far failed to displace multicrystalline and Czochralski silicon, despite four decades of innovation. One of the shortcomings of most unconventional materials has been a persistent carrier lifetime deficit in comparison to established wafer technologies, which limits the device efficiency potential. In this perspective article, we review a defect-management framework that has proven successful in enabling millisecond lifetimes in kerfless and cast materials. Control of dislocations and slowly diffusing metal point defects during growth, coupled tomore »effective control of fast-diffusing species during cell processing, is critical to enable high cell efficiencies. As a result, to accelerate the pace of novel wafer development, we discuss approaches to rapidly evaluate the device efficiency potential of unconventional wafers from injection-dependent lifetime measurements.« less

  5. Thermodynamics, Entropy, Information and the Efficiency of Solar Cells

    E-Print Network [OSTI]

    Abrams, Zeev R.

    2012-01-01

    Physical Limits to Solar Cell Efficiency, in Energy and theCarnot factor in solar-cell efficiencies. J. Phys. D: Appl.and A.J. Nozik, Solar conversion efficiency of photovoltaic

  6. Berkeley Lab Sheds Light on Improving Solar Cell Efficiency

    E-Print Network [OSTI]

    Lawrence Berkeley National Laboratory

    2007-01-01

    light on improving solar cell efficiency Ernest Orlandomanufacturing methods produce solar cells with an efficiencythe impaired performance of solar cells manufactured from

  7. InGaAs/GaAsP strain balanced multi-quantum wires grown on misoriented GaAs substrates for high efficiency solar cells

    SciTech Connect (OSTI)

    Alonso-Álvarez, D.; Thomas, T.; Führer, M.; Hylton, N. P.; Ekins-Daukes, N. J.; Lackner, D.; Philipps, S. P.; Bett, A. W.; Sodabanlu, H.; Fujii, H.; Watanabe, K.; Sugiyama, M.; Nasi, L.; Campanini, M.

    2014-08-25

    Quantum wires (QWRs) form naturally when growing strain balanced InGaAs/GaAsP multi-quantum wells (MQW) on GaAs [100] 6° misoriented substrates under the usual growth conditions. The presence of wires instead of wells could have several unexpected consequences for the performance of the MQW solar cells, both positive and negative, that need to be assessed to achieve high conversion efficiencies. In this letter, we study QWR properties from the point of view of their performance as solar cells by means of transmission electron microscopy, time resolved photoluminescence and external quantum efficiency (EQE) using polarised light. We find that these QWRs have longer lifetimes than nominally identical QWs grown on exact [100] GaAs substrates, of up to 1??s, at any level of illumination. We attribute this effect to an asymmetric carrier escape from the nanostructures leading to a strong 1D-photo-charging, keeping electrons confined along the wire and holes in the barriers. In principle, these extended lifetimes could be exploited to enhance carrier collection and reduce dark current losses. Light absorption by these QWRs is 1.6 times weaker than QWs, as revealed by EQE measurements, which emphasises the need for more layers of nanostructures or the use light trapping techniques. Contrary to what we expected, QWR show very low absorption anisotropy, only 3.5%, which was the main drawback a priori of this nanostructure. We attribute this to a reduced lateral confinement inside the wires. These results encourage further study and optimization of QWRs for high efficiency solar cells.

  8. High Efficiency CdTe and CIGS Thin Film Solar Cells: Highlights of the Technologies Challenges (Presentation)

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield MunicipalTechnical Report:Speeding accessby aLED Street LightingFrom theHigh Efficiency CdTe and CIGS

  9. High-Efficiency Low-Cost Solar Receiver for Use in a Supercritical CO2 Recompression Cycle

    Broader source: Energy.gov [DOE]

    This presentation was delivered at the SunShot Concentrating Solar Power (CSP) Program Review 2013, held April 23–25, 2013 near Phoenix, Arizona.

  10. Remnant PbI{sub 2}, an unforeseen necessity in high-efficiency hybrid perovskite-based solar cells?

    SciTech Connect (OSTI)

    Cao, Duyen H.; Stoumpos, Constantinos C.; Malliakas, Christos D.; Katz, Michael J.; Hupp, Joseph T. E-mail: m-kanatzidis@northwestern.edu; Kanatzidis, Mercouri G. E-mail: m-kanatzidis@northwestern.edu; Farha, Omar K.

    2014-09-01

    Perovskite-containing solar cells were fabricated in a two-step procedure in which PbI{sub 2} is deposited via spin-coating and subsequently converted to the CH{sub 3}NH{sub 3}PbI{sub 3} perovskite by dipping in a solution of CH{sub 3}NH{sub 3}I. By varying the dipping time from 5 s to 2 h, we observe that the device performance shows an unexpectedly remarkable trend. At dipping times below 15 min the current density and voltage of the device are enhanced from 10.1 mA/cm{sup 2} and 933 mV (5 s) to 15.1 mA/cm{sup 2} and 1036 mV (15 min). However, upon further conversion, the current density decreases to 9.7 mA/cm{sup 2} and 846 mV after 2 h. Based on X-ray diffraction data, we determined that remnant PbI{sub 2} is always present in these devices. Work function and dark current measurements showed that the remnant PbI{sub 2} has a beneficial effect and acts as a blocking layer between the TiO{sub 2} semiconductor and the perovskite itself reducing the probability of back electron transfer (charge recombination). Furthermore, we find that increased dipping time leads to an increase in the size of perovskite crystals at the perovskite-hole-transporting material interface. Overall, approximately 15 min dipping time (?2% unconverted PbI{sub 2}) is necessary for achieving optimal device efficiency.

  11. Preparation of copper-indium-gallium-diselenide precursor films by electrodeposition for fabricating high efficiency solar cells

    DOE Patents [OSTI]

    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)

    1999-02-16

    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.

  12. Towards high efficiency thin-film crystalline silicon solar cells: The roles of light trapping and non-radiative recombinations

    E-Print Network [OSTI]

    ://dx.doi.org/10.1063/1.4867008] I. INTRODUCTION A central focus of crystalline silicon (c-Si) solar cell research important evaluation criterion for photovoltaic (PV) technology. Therefore, research on novel structures

  13. High efficiency InGaAs solar cells on Si by InP layer transfer James M. Zahler

    E-Print Network [OSTI]

    Atwater, Harry

    illumination was achieved using an InGaP/GaAs/InGaAs triple-junction cell design with an In- GaAs bottom cell.1 benefit from such an InP/Si substrate.2 Additionally, a proposed four-junction solar cell, fabri- cated for bulk InP in the fabrication of such a four-junction solar cell could significantly reduce the substrate

  14. Efficient solar cooling: first ever non-tracking solar collectors powering a double effect absorption chiller

    E-Print Network [OSTI]

    Poiry, Heather Marie

    2011-01-01

    able to operate with a solar thermal efficiency of 50% at afor the total solar irradiation Efficiency is calculated by:of the solar collector thermal efficiency. 6.2 Chiller

  15. High-Efficiency Receivers for Supercritical Carbon Dioxide Cycles...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    More Documents & Publications High-Efficiency Low-Cost Solar Receiver for Use in a Supercritical CO2 Recompression Cycle - FY13 Q1 High-Efficiency Receivers for...

  16. High-efficiency, thin-film solar cells. Annual subcontractor report, 1 July 1991--30 June 1992

    SciTech Connect (OSTI)

    Gale, R.P.

    1994-01-01

    This report describes work on a 3-year research program to investigate thin-film GaAs/GaInP cells using the cleavage of lateral epitaxial film for transfer (CLEFT) technique, and to determine the process to enable overgrowth of GaAs films using organometallic chemistry. Application of the CLEFT thin-film technique to GaInP/GaAs solar cells and organometallic overgrowth was investigated. A problem of alloy contamination was identified and controlled, leading to higher quality layers. Solar cell structures were grown and fabricated using previously determined growth parameters for GaAs and GaInP. With the improved materials developed significant improvements were made in solar cell performance. Conditions for in-situ overgrowth by organometallic chemical vapor deposition (OMCVD) were determined and continuous GaAs layers were grown over a separation mask layer. The layers were successfully separated from their substrate using the CLEFT process, demonstrating the application of overgrowth using OM chemistry with HCl.

  17. Ion implanted silicon solar cells with 18% conversion efficiency

    SciTech Connect (OSTI)

    Spitzer, M.B.; Keavney, C.J.; Milstein, J.B.; Tobin, S.P.

    1984-05-01

    The results of research on the basic understanding of high efficiency in silicon solar cells are presented. It is shown that through the use of low resistivity silicon, texture-etching, ion implantation, surface passivation, and Ta/sub 2/O/sub 5/ antireflection coatings, very high performance can be obtained. Cells with 18% AMI conversion efficiency (100 mW/cm/sup 2/, 28/sup 0/C) are reported, and research to increase the performance to much higher levels is described.

  18. High efficiency incandescent lighting

    DOE Patents [OSTI]

    Bermel, Peter; Ilic, Ognjen; Chan, Walker R.; Musabeyoglu, Ahmet; Cukierman, Aviv Ruben; Harradon, Michael Robert; Celanovic, Ivan; Soljacic, Marin

    2014-09-02

    Incandescent lighting structure. The structure includes a thermal emitter that can, but does not have to, include a first photonic crystal on its surface to tailor thermal emission coupled to, in a high-view-factor geometry, a second photonic filter selected to reflect infrared radiation back to the emitter while passing visible light. This structure is highly efficient as compared to standard incandescent light bulbs.

  19. High-Efficiency Solar Cells for Large-Scale Electricity Generation & Design Considerations for the Related Optics (Presentation)

    SciTech Connect (OSTI)

    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.

    2007-09-17

    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.

  20. High Efficiency, Clean Combustion

    SciTech Connect (OSTI)

    Donald Stanton

    2010-03-31

    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

  1. Los Alamos Discovers Super Efficient Solar Using Perovskite Crystals

    SciTech Connect (OSTI)

    Mohite, Aditya; Nie, Wanyi

    2015-01-29

    State-of-the-art photovoltaics using high-purity, large-area, wafer-scale single-crystalline semiconductors grown by sophisticated, high temperature crystal-growth processes offer promising routes for developing low-cost, solar-based clean global energy solutions for the future. Solar cells composed of the recently discovered material organic-inorganic perovskites offer the efficiency of silicon, yet suffer from a variety of deficiencies limiting the commercial viability of perovskite photovoltaic technology. In research to appear in Science, Los Alamos National Laboratory researchers reveal a new solution-based hot-casting technique that eliminates these limitations, one that allows for the growth of high-quality, large-area, millimeter-scale perovskite crystals and demonstrates that highly efficient and reproducible solar cells with reduced trap assisted recombination can be realized.

  2. Optical design and efficiency improvement for organic luminescent solar concentrators

    E-Print Network [OSTI]

    Hirst, Linda

    in a standard flat-plate PV panel3 . Nonimaging Optics: Efficient Design for Illumination and SolarOptical design and efficiency improvement for organic luminescent solar concentrators Chunhua Wanga and efficiency improvement method. Keywords: Organic luminescent solar concentrators, Photovoltaic, solar energy

  3. TiO{sub 2} nanospheres and spiny nanospheres for high conversion efficiency in dye-sensitized solar cells with gel electrolyte

    SciTech Connect (OSTI)

    Wang, Juangang, E-mail: shanxiwangjuangang@126.com; Chen, Tie-dan [College of Chemistry and Material Science, Huaibei Normal University, Huaibei 235000, Anhui (China)

    2014-04-07

    In this paper, the TiO{sub 2} nanospheres and spiny nanospheres were synthesized as the photoanode films of dye-sensitized solar cells (DSSCs) with quasi-solid electrolyte for the improvement of solar conversion efficiency. For a given film thickness, the spherical photoanode films have shorter electron transport time and several times slower recombination than those of nanoparticles, indicating that the charge-collection efficiencies of the spherical photoanodes were markedly improved. DSSCs containing the TiO{sub 2} spherical photoelectrode exhibited higher short circuit current because of this specific morphology.

  4. Structure of All-Polymer Solar Cells Impedes Efficiency

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (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...

  5. Low-cost, Efficient, Flexible Solar Cells with 3D Nanopillar...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Fan at Berkeley Lab have invented a method for growing highly regular, single-crystalline nanopillar arrays of optically active semiconductors to produce efficient, 3D solar...

  6. Ultrahigh Efficiency Multiband Solar Cells Final Report for Director's Innovation Initiative Project DII-2005-1221

    E-Print Network [OSTI]

    Ager III, Joel W.; Walukiewicz, W.; Yu, Kin Man

    2006-01-01

    triple junction (3J) cells under maximum concentration [2,3] and cells of this design are used in high-efficiency solar

  7. A Novel Low Cost Solar Central Inverters Topology With 99.2 % Efficiency Heiko Preckwinkel and

    E-Print Network [OSTI]

    Noé, Reinhold

    A Novel Low Cost Solar Central Inverters Topology With 99.2 % Efficiency Heiko Preckwinkel IGBT-based 3-level modules are limited to about 300- 600 A nominal current. A Novel Low Cost Solar)», «Transformer», Abstract For solar central inverters, high efficiency is still a very important issue

  8. Efficient Organic Solar Cells with Helical Perylene Diimide Electron M. Tuan Trinh,

    E-Print Network [OSTI]

    Efficient Organic Solar Cells with Helical Perylene Diimide Electron Acceptors Yu Zhong, M. Tuan, and recombination mechanisms in a highly efficient fullerene-free organic bulk-heterojunction (BHJ) solar cell. The majority of organic solar cells utilize fullerene and its derivatives (PC61BM, PC71BM, etc

  9. Solar Energy Materials & Solar Cells 91 (2007) 15991610 Improving solar cell efficiency using photonic band-gap materials

    E-Print Network [OSTI]

    Dowling, Jonathan P.

    2007-01-01

    efficiency of solar cell devices without using concentrators. r 2007 Elsevier B.V. All rights reserved) solar energy conversion systems (or solar cells) are the most widely used power systems. HoweverSolar Energy Materials & Solar Cells 91 (2007) 1599­1610 Improving solar cell efficiency using

  10. High Penetration Solar Deployment Funding Opportunity

    Broader source: Energy.gov [DOE]

    Through the High Penetration Solar Deployment program, DOE is funding solar projects that are accelerating the placement of solar photovoltaic (PV) systems into existing and newly designed...

  11. Nanocrystal Solar Cells

    E-Print Network [OSTI]

    Gur, Ilan

    2006-01-01

    will enable optimal solar cell efficiencies in multiple bandlow cost, high efficiency hybrid solar cells. 4.6 Conclusioncosts and improving efficiencies of solar photovoltaic

  12. Thermodynamics, Entropy, Information and the Efficiency of Solar Cells

    E-Print Network [OSTI]

    Abrams, Zeev R.

    2012-01-01

    At Silicon Solar Cell Performance. Energ. Conv. 11, 63 (efficiency of solar cells. Sol. Energ. Mat. Sol. C. 139. E.Solar Cells: Comparison between Carrier Multiplication and Down- Conversion, Sol. Energ.

  13. Thermodynamics, Entropy, Information and the Efficiency of Solar Cells

    E-Print Network [OSTI]

    Abrams, Zeev R.

    2012-01-01

    two terminal tandem solar cell. Physica E 14, 96 (2002).ultimate efficiency of solar cells. Sol. Energ. Mat. Sol. C.91, 43. T. Markvart, Solar cell as a heat engine: energy–

  14. Thermodynamics, Entropy, Information and the Efficiency of Solar Cells

    E-Print Network [OSTI]

    Abrams, Zeev R.

    2012-01-01

    efficiency of a specific solar cell design. Graph reproducedrequired for most solar cell designs (as a function of thewould make use of 3D solar cell designs such as micro- or

  15. Thermodynamics, Entropy, Information and the Efficiency of Solar Cells

    E-Print Network [OSTI]

    Abrams, Zeev R.

    2012-01-01

    91, 43. T. Markvart, Solar cell as a heat engine: energy–Tiedje, Physical Limits to Solar Cell Efficiency, in EnergyThe Carnot Factor in Solar-Cell Theory. Solid State

  16. Minding the Gap Makes for More Efficient Solar Cells

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Minding the Gap Makes for More Efficient Solar Cells Minding the Gap Makes for More Efficient Solar Cells Print Thursday, 19 December 2013 11:01 Using novel materials to develop...

  17. Energy Efficiency First, Zero Energy Ready Homes, and Solar PV...

    Office of Environmental Management (EM)

    Energy Efficiency First, Zero Energy Ready Homes, and Solar PV Updates Energy Efficiency First, Zero Energy Ready Homes, and Solar PV Updates April 29, 2015 11:00AM to 12:30PM MDT...

  18. Manufacturing of High-Efficiency Bi-Facial Tandem Concentrator Solar Cells: February 20, 2009--August 20, 2010

    SciTech Connect (OSTI)

    Wojtczuk , S.

    2011-06-01

    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.

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

    SciTech Connect (OSTI)

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

    1996-01-01

    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.

  20. Computationally Efficient Modeling of High-Efficiency Clean Combustion...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    & Publications Computationally Efficient Modeling of High-Efficiency Clean Combustion Engines Computationally Efficient Modeling of High-Efficiency Clean Combustion Engines...

  1. WORKING QUANTUM EFFICIENCY OF CDTE SOLAR CELL Zimeng Cheng

    E-Print Network [OSTI]

    WORKING QUANTUM EFFICIENCY OF CDTE SOLAR CELL Zimeng Cheng 1 , Kwok Lo 2 , Jingong Pan 1 , Dongguo, the quantum efficiency of CdTe solar cell with various optical biases, which is titled as "Working Quantum Efficiency (WQE)", is measured. The result is compared with industrialized amorphous silicon solar cell

  2. Reliable wet-chemical cleaning of natively oxidized high-efficiency Cu(In,Ga)Se{sub 2} thin-film solar cell absorbers

    SciTech Connect (OSTI)

    Lehmann, Jascha; Lehmann, Sebastian; Lauermann, Iver; Rissom, Thorsten; Kaufmann, Christian A.; Lux-Steiner, Martha Ch.; Bär, Marcus; Sadewasser, Sascha

    2014-12-21

    Currently, Cu-containing chalcopyrite-based solar cells provide the highest conversion efficiencies among all thin-film photovoltaic (PV) technologies. They have reached efficiency values above 20%, the same performance level as multi-crystalline silicon-wafer technology that dominates the commercial PV market. Chalcopyrite thin-film heterostructures consist of a layer stack with a variety of interfaces between different materials. It is the chalcopyrite/buffer region (forming the p-n junction), which is of crucial importance and therefore frequently investigated using surface and interface science tools, such as photoelectron spectroscopy and scanning probe microscopy. To ensure comparability and validity of the results, a general preparation guide for “realistic” surfaces of polycrystalline chalcopyrite thin films is highly desirable. We present results on wet-chemical cleaning procedures of polycrystalline Cu(In{sub 1-x}Ga{sub x})Se{sub 2} thin films with an average x?=?[Ga]/([In]?+?[Ga])?=?0.29, which were exposed to ambient conditions for different times. The hence natively oxidized sample surfaces were etched in KCN- or NH{sub 3}-based aqueous solutions. By x-ray photoelectron spectroscopy, we find that the KCN treatment results in a chemical surface structure which is – apart from a slight change in surface composition – identical to a pristine as-received sample surface. Additionally, we discover a different oxidation behavior of In and Ga, in agreement with thermodynamic reference data, and we find indications for the segregation and removal of copper selenide surface phases from the polycrystalline material.

  3. HIGH EFFICIENCY SYNGAS GENERATION

    SciTech Connect (OSTI)

    Robert J. Copeland; Yevgenia Gershanovich; Brian Windecker

    2005-02-01

    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.

  4. Thermal efficiency of single-pass solar air collector

    SciTech Connect (OSTI)

    Ibrahim, Zamry; Ibarahim, Zahari; Yatim, Baharudin; Ruslan, Mohd Hafidz

    2013-11-27

    Efficiency of a finned single-pass solar air collector was studied. This paper presents the experimental study to investigate the effect of solar radiation and mass flow rate on efficiency. The fins attached at the back of absorbing plate to improve the thermal efficiency of the system. The results show that the efficiency is increased proportional to solar radiation and mass flow rate. Efficiency of the collector archived steady state when reach to certain value or can be said the maximum performance.

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

    SciTech Connect (OSTI)

    Wanlass, M.

    2012-07-01

    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.

  6. High-efficiency photovoltaic cells

    DOE Patents [OSTI]

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

    1982-06-21

    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.

  7. High efficiency diamond solar cells

    DOE Patents [OSTI]

    Gruen, Dieter M. (Downers Grove, IL)

    2008-05-06

    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.

  8. High Efficiency Integrated Package

    SciTech Connect (OSTI)

    Ibbetson, James

    2013-09-15

    Solid-state lighting based on LEDs has emerged as a superior alternative to inefficient conventional lighting, particularly incandescent. LED lighting can lead to 80 percent energy savings; can last 50,000 hours – 2-50 times longer than most bulbs; and contains no toxic lead or mercury. However, to enable mass adoption, particularly at the consumer level, the cost of LED luminaires must be reduced by an order of magnitude while achieving superior efficiency, light quality and lifetime. To become viable, energy-efficient replacement solutions must deliver system efficacies of ? 100 lumens per watt (LPW) with excellent color rendering (CRI > 85) at a cost that enables payback cycles of two years or less for commercial applications. This development will enable significant site energy savings as it targets commercial and retail lighting applications that are most sensitive to the lifetime operating costs with their extended operating hours per day. If costs are reduced substantially, dramatic energy savings can be realized by replacing incandescent lighting in the residential market as well. In light of these challenges, Cree proposed to develop a multi-chip integrated LED package with an output of > 1000 lumens of warm white light operating at an efficacy of at least 128 LPW with a CRI > 85. This product will serve as the light engine for replacement lamps and luminaires. At the end of the proposed program, this integrated package was to be used in a proof-of-concept lamp prototype to demonstrate the component’s viability in a common form factor. During this project Cree SBTC developed an efficient, compact warm-white LED package with an integrated remote color down-converter. Via a combination of intensive optical, electrical, and thermal optimization, a package design was obtained that met nearly all project goals. This package emitted 1295 lm under instant-on, room-temperature testing conditions, with an efficacy of 128.4 lm/W at a color temperature of ~2873K and 83 CRI. As such, the package’s performance exceeds DOE’s warm-white phosphor LED efficacy target for 2013. At the end of the program, we assembled an A19 sized demonstration bulb housing the integrated package which met Energy Star intensity variation requirements. With further development to reduce overall component cost, we anticipate that an integrated remote converter package such as developed during this program will find application in compact, high-efficacy LED-based lamps, particularly those requiring omnidirectional emission.

  9. High flux solar energy transformation

    DOE Patents [OSTI]

    Winston, R.; Gleckman, P.L.; O'Gallagher, J.J.

    1991-04-09

    Disclosed are multi-stage systems for high flux transformation of solar energy allowing for uniform solar intensification by a factor of 60,000 suns or more. Preferred systems employ a focusing mirror as a primary concentrative device and a non-imaging concentrator as a secondary concentrative device with concentrative capacities of primary and secondary stages selected to provide for net solar flux intensification of greater than 2000 over 95 percent of the concentration area. Systems of the invention are readily applied as energy sources for laser pumping and in other photothermal energy utilization processes. 7 figures.

  10. High flux solar energy transformation

    DOE Patents [OSTI]

    Winston, Roland (Chicago, IL); Gleckman, Philip L. (Chicago, IL); O'Gallagher, Joseph J. (Flossmoor, IL)

    1991-04-09

    Disclosed are multi-stage systems for high flux transformation of solar energy allowing for uniform solar intensification by a factor of 60,000 suns or more. Preferred systems employ a focusing mirror as a primary concentrative device and a non-imaging concentrator as a secondary concentrative device with concentrative capacities of primary and secondary stages selected to provide for net solar flux intensification of greater than 2000 over 95 percent of the concentration area. Systems of the invention are readily applied as energy sources for laser pumping and in other photothermal energy utilization processes.

  11. Optical Design Considerations for High Conversion Efficiency in Photovoltaics

    E-Print Network [OSTI]

    Ganapati, Vidya

    2015-01-01

    thermophotovoltaics. In solar photovoltaics, radiation fromto the efficiency of solar photovoltaics can have largeof efficiency in solar photovoltaics, and looks at how

  12. GaInNAs Structures Grown by MBE for High-Efficiency Solar Cells: Final Report; 25 June 1999--24 August 2002

    SciTech Connect (OSTI)

    Tu, C. W.

    2003-08-01

    The focus of this work is to improve the quality of GaInNAs by advanced thin-film growth techniques, such as digital-alloy growth techniques and migration-enhanced epitaxy (MEE). The other focus is to further investigate the properties of such materials, which are potentially beneficial for high-efficiency, multijunction solar cells. 400-nm-thick strain-compensated Ga0.92In0.08As/GaN0.03As0.97 short-period superlattices (SPSLs) are grown lattice-matched to GaAs substrates. The photoluminescence (PL) intensity of digital alloys is 3 times higher than that of random alloys at room temperature, and the improvement is even greater at low temperature, by a factor of about 12. The room-temperature PL intensity of the GaInNAs quantum well grown by the strained InAs/GaN0.023As SPSL growth mode is higher by a factor 5 as compare to the continuous growth mode. The SPSL growth method allows for independent adjustment of the In-to-Ga ratio without group III competition. MEE reduces the low-energy tail of PL, and PL peaks become more intense and sharper. The twin peaks photoluminescence of GaNAs grown on GaAs was observed at room temperature. The peaks splitting increase with increase in nitrogen alloy content. The strain-induced splitting of light-hole and heavy-hole bands of tensile-strained GaNAs is proposed as an explanation of such behavior.

  13. Efficiency of silicon solar cells containing chromium

    DOE Patents [OSTI]

    Frosch, Robert A. Administrator of the National Aeronautics and Space (New Port Beach, CA); Salama, Amal M. (New Port Beach, CA)

    1982-01-01

    Efficiency of silicon solar cells containing about 10.sup.15 atoms/cm.sup.3 of chromium is improved about 26% by thermal annealing of the silicon wafer at a temperature of 200.degree. C. to form chromium precipitates having a diameter of less than 1 Angstrom. Further improvement in efficiency is achieved by scribing laser lines onto the back surface of the wafer at a spacing of at least 0.5 mm and at a depth of less than 13 micrometers to preferentially precipitate chromium near the back surface and away from the junction region of the device. This provides an economical way to improve the deleterious effects of chromium, one of the impurities present in metallurgical grade silicon material.

  14. SUPPORTING INFORMATION Si Microwire Solar Cells: Improved Efficiency with a

    E-Print Network [OSTI]

    S1 SUPPORTING INFORMATION Si Microwire Solar Cells: Improved Efficiency with a Conformal SiO2 Layer improvements (%) of Si microwire solar cells (6 µµµµm height) after conformal SiO2 coating SiO2 thickness Jsc

  15. High Efficient Natural Gas Technologies

    Broader source: Energy.gov (indexed) [DOE]

    by: Eric Burgis Energy Solutions Center 610-796-1946 eburgis@escenter.org High Efficient Natural Gas Technologies FUPWG 5814 2 Energy Solutions Center Inc. - All Rights...

  16. Solar thermophotovoltaic efficiency potentials : surpassing photovoltaic device efficiencies

    E-Print Network [OSTI]

    Barnes, Kathryn M

    2012-01-01

    Solar energy has gained more attention in recent years due to increased concerns about the continued use of fossil fuels. Solar energy is a form of renewable energy, and solar energy technology does not release greenhouse ...

  17. Thermodynamics, Entropy, Information and the Efficiency of Solar Cells

    E-Print Network [OSTI]

    Abrams, Zeev R.

    2012-01-01

    workings of solar cells and photovoltaic power conversion tostate-of-the-art photovoltaic cells. Prog. Photovolt: Res.efficiency of an ideal photovoltaic cell with charge carrier

  18. Band Alignment Engineering in Highly Efficient Planar Perovskite...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Band Alignment Engineering in Highly Efficient Planar Perovskite Solar Cells September 22, 2015 at 4:30 pm36-428 Juan-Pablo Correa-Baena COLE POLYTECHNIQUE FDRALE DE...

  19. High-Efficiency Receivers for Supercritical Carbon Dioxide Cycles...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    R&D award program. The team, led by Brayton Energy, aims to develop and demonstrate a low-cost, high-efficiency solar receiver that is compatible with s-CO2 cycles and modern...

  20. High-Efficiency Receivers for Supercritical Carbon Dioxide Cycles...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    2012. progressreportsunshotbraytonfy12q4.pdf More Documents & Publications High-Efficiency Low-Cost Solar Receiver for Use in a Supercritical CO2 Recompression Cycle - FY13 Q1...

  1. High external quantum efficiency and fill-factor InGaN/GaN heterojunction solar cells grown by NH3-based molecular beam epitaxy

    SciTech Connect (OSTI)

    Lang, J. R.; Neufeld, C. J.; Hurni, C. A.; Cruz, S. C.; Matioli, E.; Mishra, U. K.; Speck, J. S.

    2011-04-01

    High external quantum efficiency (EQE) p-i-n heterojunction solar cellsgrown by NH3 -based molecular beam epitaxy are presented. EQE values including optical losses are greater than 50% with fill-factors over 72% when illuminated with a 1 sun AM0 spectrum. Optical absorptionmeasurements in conjunction with EQE measurements indicate an internal quantum efficiency greater than 90% for the InGaN absorbing layer. By adjusting the thickness of the top p-type GaN window contact layer, it is shown that the short-wavelength (<365 nm) quantum efficiency is limited by the minority carrier diffusion length in highly Mg-doped p-GaN.

  2. Formation of Porous Layers by Electrochemical Etching of Germanium and Gallium Arsenide for Cleave Engineered Layer Transfer (CELT) Application in High Efficiency Multi-Junction Solar Cells

    E-Print Network [OSTI]

    Fong, David Michael

    2012-01-01

    technique for LM triple junction solar cell grown on porousAnother common triple-junction solar cell utilizes a GaAstechnique for LM triple junction solar cell grown on porous

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

    SciTech Connect (OSTI)

    Vernon, S.M.

    1993-04-01

    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.

  4. Solar cell efficiency enhancement via light trapping in printable resonant

    E-Print Network [OSTI]

    Grandidier, Jonathan

    Solar cell efficiency enhancement via light trapping in printable resonant dielectric nanosphere, photovoltaics, resonant dielectric structures, solar cells * Corresponding author: e-mail jgrandid for addressing the key challenge of light trapping in thin-film solar cells. We experimentally and theoretically

  5. Investigating the efficiency of Silicon Solar cells at

    E-Print Network [OSTI]

    Attari, Shahzeen Z.

    Investigating the efficiency of Silicon Solar cells at different temperatures and wavelengths to study the characteristics of silicon photovoltaic cells (solar cells). We vary the wavelength of light as well as the temperature of the solar cell to investigate how the open voltage across the cell varies

  6. Highly Mismatched Alloys for Intermediate Band Solar Cells

    E-Print Network [OSTI]

    2005-01-01

    comparison to multijunction solar cells. A detailed balanceachieved with multijunction solar cells based on standardmultijunction designs for improving the power conversion efficiency of solar cells [

  7. Upconversion as a Viable Route to Increased Efficiency Solar Energy

    E-Print Network [OSTI]

    Firestone, Jeremy

    Upconversion as a Viable Route to Increased Efficiency Solar Energy Conversion Joshua Zide, Matt University of Delaware Energy Institute #12;Efficiency drives reduced $/W.... http://www.nrel.gov/ncpv/! Shockley-Queisser Limit! *adopted from http://www.lbl.gov/Science-Articles/Archive/MSD-full-spectrum-solar

  8. Comparative efficiencies of solar energy collectors Laboratoire de Technologie Optique

    E-Print Network [OSTI]

    Boyer, Edmond

    57 Comparative efficiencies of solar energy collectors M. Duban Laboratoire de Technologie Optique to make a compari- son between the different kinds of solar collectors : for instance, a paraboloid of the geometric efficiencies of basic collectors, by examining the cons- tancy with which each of them collects

  9. Formation of Porous Layers by Electrochemical Etching of Germanium and Gallium Arsenide for Cleave Engineered Layer Transfer (CELT) Application in High Efficiency Multi-Junction Solar Cells

    E-Print Network [OSTI]

    Fong, David Michael

    2012-01-01

    Motivation Multi-junction (MJ) solar cells show particular promise as a future clean renewable energy

  10. Amorphous Si Thin Film Based Photocathodes with High Photovoltage for Efficient Hydrogen Production

    E-Print Network [OSTI]

    Javey, Ali

    Amorphous Si Thin Film Based Photocathodes with High Photovoltage for Efficient Hydrogen Production for solar hydrogen production. With platinum as prototypical cocatalyst, a photocurrent onset potential of 0 for solar hydrogen production. KEYWORDS: Water splitting, hydrogen production, photochemistry, high

  11. Optimized Designs and Materials for Nanostructure Based Solar Cells

    E-Print Network [OSTI]

    Shao, Qinghui

    2009-01-01

    impact ionization and solar cell efficiency,” J. Appl. Phys.intermediate band high efficiency solar cell,” Prog. Inthe application of high efficiency solar cells [1-5]. The

  12. New GaInP/GaAs/GaInAs, Triple-Bandgap, Tandem Solar Cell for High-Efficiency Terrestrial Concentrator Systems

    SciTech Connect (OSTI)

    Kurtz, S.; Wanlass, M.; Kramer, C.; Young, M.; Geisz, J.; Ward, S.; Duda, A.; Moriarty, T.; Carapella, J.; Ahrenkiel, P.; Emery. K.; Jones, K.; Romero, M.; Kibbler, A.; Olson, J.; Friedman, D.; McMahon, W.; Ptak, A.

    2005-11-01

    GaInP/GaAs/GaInAs three-junction cells are grown in an inverted configuration on GaAs, allowing high quality growth of the lattice matched GaInP and GaAs layers before a grade is used for the 1-eV GaInAs layer. Using this approach an efficiency of 37.9% was demonstrated.

  13. Upside-Down Solar Cell Achieves Record Efficiencies (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2010-12-01

    The inverted metamorphic multijunction (IMM) solar cell is an exercise in efficient innovation - literally, as the technology boasted the highest demonstrated efficiency for converting sunlight into electrical energy at its debut in 2005. Scientists at the National Renewable Energy Laboratory (NREL) inverted the conventional photovoltaic (PV) structure to revolutionary effect, achieving solar conversion efficiencies of 33.8% and 40.8% under one-sun and concentrated conditions, respectively.

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

    E-Print Network [OSTI]

    Summers, Edward K

    2010-01-01

    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 ...

  15. Improved efficiency of smooth and aligned single walled carbon nanotube/silicon hybrid solar cells

    E-Print Network [OSTI]

    Reed, Mark

    and versatility of CNTs in energy storage and conversion devices. In fact, CNT has already been used to contactImproved efficiency of smooth and aligned single walled carbon nanotube/silicon hybrid solar cells on silicon (Si) together with post treatments result in SWNT/Si hybrid solar cells with unprecedented high

  16. Ultrahigh Efficiency Multiband Solar Cells Final Report for Director's Innovation Initiative Project DII-2005-1221

    E-Print Network [OSTI]

    Ager III, Joel W.; Walukiewicz, W.; Yu, Kin Man

    2006-01-01

    W. Warta, “Solar Cell Efficiency Tables (Version 21),” Prog.Marti. , “Increasing the Efficiency of Ideal Solar Cells byP. Corkish, “Limiting efficiency of a multi-band solar cell

  17. CRADA Final Report: Process development for hybrid solar cells

    E-Print Network [OSTI]

    Ager, Joel W

    2011-01-01

    the high efficiency, high voltage hybrid tandem solar celltarget efficiency of 30%, the hybrid tandem solar cells have

  18. Ultrahigh Efficiency Multiband Solar Cells Final Report for Director's Innovation Initiative Project DII-2005-1221

    E-Print Network [OSTI]

    Ager III, Joel W.; Walukiewicz, W.; Yu, Kin Man

    2006-01-01

    Assessment of Multijunction Solar Cell Performance inS. Igari, and W. Warta, “Solar Cell Efficiency Tables (C. , “Assessment of Multijunction Solar Cell Performance in

  19. New solar cell technology captures high-energy photons more efficientl...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    (click to enlarge) Argonne's Center for Nanoscale Materials (click to enlarge) New solar cell technology captures high-energy photons more efficiently By Jared Sagoff *...

  20. Recent progress in enhancing solar-to-hydrogen efficiency

    SciTech Connect (OSTI)

    Chen, Jianqing; Yang, Donghui; Song, Dan; Jiang, Jinghua; Ma, Aibin; Hu, Michael Z.; Ni, Chaoying

    2015-01-01

    Solar water splitting is a promising and ideal route for renewable production of hydrogen by using the most abundant resources of solar light and water. Focusing on the working principal of solar water splitting, including photon absorption and exciton generation in semiconductor, exciton separation and transfer to the surface of semiconductor, and respective electron and hole reactions with absorbed surface species to generate hydrogen and oxygen, this review covers the comprehensive efforts and findings made in recent years on the improvement for the solar-to-hydrogen efficiency (STH) determined by a combination of light absorption process, charge separation and migration, and catalytic reduction and oxidation reactions. Critical evaluation is attempted on the strategies for improving solar light harvesting efficiency, enhancing charge separation and migration, and improving surface reactions. Towards the end, new and emerging technologies for boosting the STH efficiency are discussed on multiple exciton generation, up-conversion, multi-strategy modifications and the potentials of organometal hybrid perovskite materials.

  1. DEVELOPMENT OF A NOVEL PRECURSOR FOR THE PREPARATION BY SELENIZATION OF HIGH EFFICIENCY CuInGaSe2/CdS THIN FILM SOLAR CELLS

    E-Print Network [OSTI]

    Romeo, Alessandro

    /CdS THIN FILM SOLAR CELLS N. Romeo1 , A. Bosio1 , V. Canevari2 , R. Tedeschi1 , S. Sivelli1 , A. Solar cells prepared by depositing in sequence on top of the CuInGaSe2 film 60 nm of CdS, 100 nm of pure(InGa)Se2, Thin Films, Selenization 1 INTRODUCTION CuInGaSe2 based solar cells exhibit the highest

  2. Estimating the Cost and Energy Efficiency of a Solar Water Heater...

    Broader source: Energy.gov (indexed) [DOE]

    Solar water heaters are more efficient the gas or electric heaters. | Chart credit ENERGY STAR Solar water heaters are more efficient the gas or electric heaters. | Chart credit...

  3. High-Flux Microchannel Solar Receiver

    Broader source: Energy.gov [DOE]

    This fact sheet describes a high-flux, microchannel solar receiver project awarded under the DOE's 2012 SunShot Concentrating Solar Power R&D award program. The team, led by Oregon State University, is working to demonstrate a microchannel-based solar receiver capable of absorbing high solar flux, while using a variety of liquid and gaseous working fluids. High-flux microchannel receivers have the potential to dramatically reduce the size and cost of a solar receiver by minimizing re-radiation and convective losses.

  4. Parabolic trough solar collectors : design for increasing efficiency

    E-Print Network [OSTI]

    Figueredo, Stacy L. (Stacy Lee), 1981-

    2011-01-01

    Parabolic trough collectors are a low cost implementation of concentrated solar power technology that focuses incident sunlight onto a tube filled with a heat transfer fluid. The efficiency and cost of the parabolic trough ...

  5. Silicon Ink Technology Offers Path to Higher Efficiency Solar...

    Broader source: Energy.gov (indexed) [DOE]

    Silicon Ink Technology Offers Path to Higher Efficiency Solar Cells at Lower Cost Partnering with Sunnyvale-based Innovalight, which was acquired by DuPont in July 2011, EERE...

  6. Multi-scale framework for the accelerated design of high-efficiency...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Multi-scale framework for the accelerated design of high-efficiency organic photovoltaic cells Organic and hybrid organicinorganic solar cells (OSC) offer a promising low-cost...

  7. High Efficiency Engine Technologies Program

    SciTech Connect (OSTI)

    Rich Kruiswyk

    2010-07-13

    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.

  8. "Tuning" microalgae for high photosynthesis efficiency

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    "Tuning" Microalgae For High Photosynthesis Efficiency "Tuning" microalgae for high photosynthesis efficiency Los Alamos scientist Richard Sayre and his team of researchers have...

  9. Mode Splitting for Efficient Plasmoinc Thin-film Solar Cell

    E-Print Network [OSTI]

    Li, Tong; Jiang, Chun

    2010-01-01

    We propose an efficient plasmonic structure consisting of metal strips and thin-film silicon for solar energy absorption. We numerically demonstrate the absorption enhancement in symmetrical structure based on the mode coupling between the localized plasmonic mode in Ag strip pair and the excited waveguide mode in silicon slab. Then we explore the method of symmetry-breaking to excite the dark modes that can further enhance the absorption ability. We compare our structure with bare thin-film Si solar cell, and results show that the integrated quantum efficiency is improved by nearly 90% in such thin geometry. It is a promising way for the solar cell.

  10. CuInSe2 and its alloys are the leading choice for absorber layers in high-efficiency thin film solar cells due to their direct gap, high absorption coefficient and

    E-Print Network [OSTI]

    Rockett, Angus

    in CuInSe2. Epitaxial CuInSe2 thin films were deposited on GaAs bicrystal substrates using a hybrid film solar cells due to their direct gap, high absorption coefficient and excellent thermal stability epilayers to the GaAs bicrystal substrate. This allows isolation and optical characterization of individual

  11. Sunshot Initiative High Penetration Solar Portal

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    The DOE SunShot Initiative is a collaborative national initiative to make solar energy cost-competitive with other forms of energy by the end of the decade. Reducing the installed cost of solar energy systems by about 75% will drive widespread large-scale adoption of this renewable energy and restore U.S. leadership in the global clean energy race. The High Penetration Solar Portal was created as a resource to aggregate the most relevant and timely information related to high penetration solar scenarios and integrating solar into the grid. The site is designed so that utilities, grant awardees, regulators, researchers, and other solar professionals can easily share data, case studies, lessons learned, and demonstration project findings. [from https://solarhighpen.energy.gov/about_the_high_penetration_solar_portal

  12. NREL Researchers Demonstrate External Quantum Efficiency Surpassing 100% in a Quantum Dot Solar Cell (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2011-12-01

    A new device that produces and collects multiple electrons per photon could yield inexpensive, high-efficiency photovoltaics. A new device developed through research at the National Renewable Energy Laboratory (NREL) reduces conventional losses in photovoltaic (PV) solar cells, potentially increasing the power conversion efficiency-but not the cost-of the solar cells. Solar cells convert optical energy from the sun into usable electricity; however, almost 50% of the incident energy is lost as heat with present-day technologies. High-efficiency, multi-junction cells reduce this heat loss, but their cost is significantly higher. NREL's new device uses excess energy in solar photons to create extra charges rather than heat. This was achieved using 5-nanometer-diameter quantum dots of lead selenide (PbSe) tightly packed into a film. The researchers chemically treated the film, and then fabricated a device that yielded an external quantum efficiency (number of electrons produced per incident photon) exceeding 100%, a value beyond that of all current solar cells for any incident photon. Quantum dots are known to efficiently generate multiple excitons (a bound electron-hole pair) per absorbed high-energy photon, and this device definitively demonstrates the collection of multiple electrons per photon in a PV cell. The internal quantum efficiency corrects for photons that are not absorbed in the photoactive layer and shows that the PbSe film generates 30% to 40% more electrons in the high-energy spectral region than is possible with a conventional solar cell. While the unoptimized overall power conversion efficiency is still low (less than 5%), the results have important implications for PV because such high quantum efficiency can lead to more electrical current produced than possible using present technologies. Furthermore, this fabrication is also amenable to inexpensive, high-throughput roll-to-roll manufacturing.

  13. Project Profile: Development and Productization of High-Efficiency, Low-Cost Building-Integrated PV Shingles Using Monocrystalline Silicon Thin-Film Solar Cells

    Office of Energy Efficiency and Renewable Energy (EERE)

    The Solexel-OC team is developing a BIPV roofing shingle product that includes low-profile solar modules and a unique attachment system that will be fastened directly to the roof and incorporates...

  14. European Photovoltaic Solar Energy Conference, Frankfurt, Germany, 24-28 September 2012, 2AO.2.4 HIGH EFFICIENCY BACK-CONTACT BACK-JUNCTION SILICON SOLAR CELLS WITH CELL

    E-Print Network [OSTI]

    as minimizing the consumption of energy and material. The effect of the cell thickness on the solar cell27th European Photovoltaic Solar Energy Conference, Frankfurt, Germany, 24-28 September 2012, 2AO.2 Institute for Solar Energy Research Hamelin (ISFH), Am Ohrberg 1, D-31860 Emmerthal, Germany 2 Renewable

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

    E-Print Network [OSTI]

    Viswanathan, R.

    2011-01-01

    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-

  16. Estimating the Cost and Energy Efficiency of a Solar Water Heater...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Estimating the Cost and Energy Efficiency of a Solar Water Heater Estimating the Cost and Energy Efficiency of a Solar Water Heater March 2, 2015 - 3:09pm Addthis Solar water...

  17. Toward High-Performance Organic-Inorganic Hybrid Solar Cells: Bringing Conjugated Polymers and Inorganic Nanocrystals in Close

    E-Print Network [OSTI]

    Lin, Zhiqun

    to traditional silicon solar cells due to the capacity of producing high- efficiency solar energy in a cost of nanostructured high-performance, lightweight, flexible, large-area, and low- cost hybrid solar cells. HoweverToward High-Performance Organic-Inorganic Hybrid Solar Cells: Bringing Conjugated Polymers

  18. Limiting and realistic efficiencies of multi-junction solar Photonic Materials Group, FOM institute AMOLF, Amsterdam

    E-Print Network [OSTI]

    Polman, Albert

    Limiting and realistic efficiencies of multi-junction solar cells Photonic Materials Group, FOM of multi-junction solar cells, varying the number of subcells, the concentration of solar light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.4 Multi-junction Solar cells

  19. Recent developments in high-efficiency PV cells

    SciTech Connect (OSTI)

    Deb, S.

    2000-05-22

    Enormous progress has been made in recent years on a number of photovoltaic (PV) materials and devices in terms of conversion efficiencies. Ultrahigh-efficiency (>30{percent}) PV cells have been fabricated from gallium arsenide (GaAs) and its ternary alloys such as gallium indium phosphide (GaInP{sub 2}). The high-efficiency GaAs-based solar cells are being produced on a commercial scale, particularly for space applications. Efficiencies in the range of 18{percent} to 24{percent} have been achieved in traditional silicon-based devices fabricated from both multicrystalline and single-crystal materials. Major advances in efficiency have also been made on various thin-film solar cells based on amorphous silicon (aSi:H), copper gallium indium diselenide (CIGS), and cadmium telluride materials. This paper gives a brief overview of the recent progress in PV cell efficiencies based on these materials and devices.

  20. High Efficiency Room Air Conditioner

    SciTech Connect (OSTI)

    Bansal, Pradeep

    2015-01-01

    This project was undertaken as a CRADA project between UT-Battelle and Geberal Electric Company and was funded by Department of Energy to design and develop of a high efficiency room air conditioner. A number of novel elements were investigated to improve the energy efficiency of a state-of-the-art WAC with base capacity of 10,000 BTU/h. One of the major modifications was made by downgrading its capacity from 10,000 BTU/hr to 8,000 BTU/hr by replacing the original compressor with a lower capacity (8,000 BTU/hr) but high efficiency compressor having an EER of 9.7 as compared with 9.3 of the original compressor. However, all heat exchangers from the original unit were retained to provide higher EER. The other subsequent major modifications included- (i) the AC fan motor was replaced by a brushless high efficiency ECM motor along with its fan housing, (ii) the capillary tube was replaced with a needle valve to better control the refrigerant flow and refrigerant set points, and (iii) the unit was tested with a drop-in environmentally friendly binary mixture of R32 (90% molar concentration)/R125 (10% molar concentration). The WAC was tested in the environmental chambers at ORNL as per the design rating conditions of AHAM/ASHRAE (Outdoor- 95F and 40%RH, Indoor- 80F, 51.5%RH). All these modifications resulted in enhancing the EER of the WAC by up to 25%.

  1. EE Solar Energy Efficiency Solar | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX E LISTStar2-0057-EA Jump to:of the NationalDynetek Europe GmbHED F Man (Krefeld,EE Solar

  2. Cu(In,Ga)Se2 alloys are the leading choice for absorber layers in high-efficiency thin film solar cells due to their direct gap, high absorption

    E-Print Network [OSTI]

    Rockett, Angus

    film solar cells due to their direct gap, high absorption coefficient and excellent thermal stability]/[In+Ga]SubstrateCrystalSample *Negligible amount of Ga diffused into back of film from substrate; not detectable by EDX Device structure GaAs(In,Ga)SePhotoluminescence Excitation Spectroscopy of Cu(In,Ga)Se22 Thin FilmsThin Films Damon Hebert, Julio Soares, Marie Mayer, Angus

  3. DEVELOPMENT OF A NOVEL PRECURSOR FOR THE PREPARATION BY SELENIZATION OF HIGH EFFICIENCY CuInGaSe2/CdS THIN FILM SOLAR CELLS

    E-Print Network [OSTI]

    Romeo, Alessandro

    /CdS THIN FILM SOLAR CELLS N. Romeo1 , A. Bosio1 , V. Canevari2 , R. Tedeschi1 , S. Sivelli1 , A, Italy 3 Scientific and Technological Department, University of Verona, Italy 4 ETH Zürich Thin Films@phys.ethz.ch ABSTRACT: A novel precursor suitable to prepare uniform CuInGaSe2 thin films on an 1 inch2 area has been

  4. Tunable Localized Surface Plasmon-Enabled Broadband Light-Harvesting Enhancement for High-Efficiency Panchromatic Dye-Sensitized Solar Cells

    E-Print Network [OSTI]

    Dang, Xiangnan

    In photovoltaic devices, light harvesting (LH) and carrier collection have opposite relations with the thickness of the photoactive layer, which imposes a fundamental compromise for the power conversion efficiency (PCE). ...

  5. High-Power Solar PanelHigh-Power Solar Panel Gives your mission electricity.

    E-Print Network [OSTI]

    Waliser, Duane E.

    Medium-Power Solar Panel 15 25 Gives your mission electricity. 8 POWER LIMIT 15 PROS: Low cost, medium mass. LastsHigh-Power Solar PanelHigh-Power Solar Panel 25 Gives your mission electricity. 9 POWER LIMIT 20 40 PROS: Medium cost, medium mass. Lasts a few years. CONS: Must have sunlight. Only works during daylight

  6. Intermediate Mirrors to Reach Theoretical Efficiency Limits of Multi-Bandgap Solar Cells

    E-Print Network [OSTI]

    Ganapati, Vidya; Yablonovitch, Eli

    2014-01-01

    Creating a single bandgap solar cell that approaches the Shockley-Queisser limit requires a highly reflective rear mirror. This mirror enhances the voltage of the solar cell by providing photons with multiple opportunities for escaping out the front surface. Efficient external luminescence is a pre-requisite for high voltage. Intermediate mirrors in a multijunction solar cell can enhance the voltage for each cell in the stack. These intermediate mirrors need to have the added function of transmitting the below bandgap photons to the next cell in the stack. In this work, we quantitatively establish the efficiency increase possible with the use of intermediate selective reflectors between cells in a tandem stack. The absolute efficiency increase can be up to ~6% in dual bandgap cells with optimal intermediate and rear mirrors. A practical implementation of an intermediate selective mirror is an air gap sandwiched by antireflection coatings. The air gap provides perfect reflection for angles outside the escape c...

  7. Efficient Polymer Solar Cells - Energy Innovation Portal

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submitKansas Nuclear Profile 2010MesoscopyStaffEfficiency ExchangeStartup America

  8. Plasmonic Nanostructure Design for Efficient Light Coupling into Solar Cells

    E-Print Network [OSTI]

    Atwater, Harry

    . Photovoltaics (PV) technology is currently enjoying sub- stantial growth and investment. Although there are manyPlasmonic Nanostructure Design for Efficient Light Coupling into Solar Cells Vivian E. Ferry, Luke Physics, California Institute of Technology, Pasadena, California 91125 Received July 25, 2008; Revised

  9. New Multijunction Design Leads to Ultra-Efficient Solar Cell; Highlights in Research & Development, NREL (National Renewable Energy Laboratory)

    SciTech Connect (OSTI)

    2015-09-01

    NREL has demonstrated a 45.7% conversion efficiency for a four-junction solar cell at 234 suns concentration. This achievement represents one of the highest photovoltaic research cell efficiencies ever achieved across all types of solar cells. NREL's new solar cell, which is designed for operation in a concentrator photovoltaic (CPV) system where it can receive more than 1,000 suns of concentrated sunlight, greatly improves earlier designs by adding an additional high quality absorber layer to achieve an ultra-high efficiency.

  10. Efficiency enhancement of luminescent solar concentrations for photovoltaic technologies

    E-Print Network [OSTI]

    Wang, Chunhua

    2011-01-01

    1.1 Solar Energy . . . . . . . . .glass-?lms. Solar Energy Materials and Solar Cells, 33(4):concentrator. Solar Energy Materials and Solar Cells, 93(8):

  11. High Penetration Solar Deployment | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    24.7 million to fund six projects to increase the growth of grid-tied solar photovoltaic systems. Part of the SunShot Systems Integration efforts, the goal of the High...

  12. A low cost high flux solar simulator

    E-Print Network [OSTI]

    Codd, Daniel S.

    A low cost, high flux, large area solar simulator has been designed, built and characterized for the purpose of studying optical melting and light absorption behavior of molten salts. Seven 1500 W metal halide outdoor ...

  13. High temperature solar selective coatings

    DOE Patents [OSTI]

    Kennedy, Cheryl E

    2014-11-25

    Improved solar collectors (40) comprising glass tubing (42) attached to bellows (44) by airtight seals (56) enclose solar absorber tubes (50) inside an annular evacuated space (54. The exterior surfaces of the solar absorber tubes (50) are coated with improved solar selective coatings {48} which provide higher absorbance, lower emittance and resistance to atmospheric oxidation at elevated temperatures. The coatings are multilayered structures comprising solar absorbent layers (26) applied to the meta surface of the absorber tubes (50), typically stainless steel, topped with antireflective Savers (28) comprising at least two layers 30, 32) of refractory metal or metalloid oxides (such as titania and silica) with substantially differing indices of refraction in adjacent layers. Optionally, at least one layer of a noble metal such as platinum can be included between some of the layers. The absorbent layers cars include cermet materials comprising particles of metal compounds is a matrix, which can contain oxides of refractory metals or metalloids such as silicon. Reflective layers within the coating layers can comprise refractory metal silicides and related compounds characterized by the formulas TiSi. Ti.sub.3SiC.sub.2, TiAlSi, TiAN and similar compounds for Zr and Hf. The titania can be characterized by the formulas TiO.sub.2, Ti.sub.3O.sub.5. TiOx or TiO.sub.xN.sub.1-x with x 0 to 1. The silica can be at least one of SiO.sub.2, SiO.sub.2x or SiO.sub.2xN.sub.1-x with x=0 to 1.

  14. High-Performance Home Technologies: Solar Thermal & Photovoltaic...

    Energy Savers [EERE]

    High-Performance Home Technologies: Solar Thermal & Photovoltaic Systems; Volume 6 Building America Best Practices Series High-Performance Home Technologies: Solar Thermal &...

  15. Project Profile: High-Flux Microchannel Solar Receiver | Department...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    high-temperature solar receivers by applying microchannel heat-transfer technology to solar-receiver design. The extremely high heat-transfer rates afforded by microchannels...

  16. High Temperature Thermal Array for Next Generation Solar Thermal...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    High Temperature Thermal Array for Next Generation Solar Thermal Power Production High Temperature Thermal Array for Next Generation Solar Thermal Power Production This...

  17. High Operating Temperature Heat Transfer Fluids for Solar Thermal...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    High Operating Temperature Heat Transfer Fluids for Solar Thermal Power Generation FY13 Q1 High Operating Temperature Heat Transfer Fluids for Solar Thermal Power Generation FY13...

  18. Kauai, Hawaii: Solar Resource Analysis and High-Penetration PV...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Kauai, Hawaii: Solar Resource Analysis and High-Penetration PV Potential Kauai, Hawaii: Solar Resource Analysis and High-Penetration PV Potential This study looks at the technical...

  19. Core/Shell heterojunction nanowire solar cell fabricated by lithographically patterned nanowire electrodeposition method

    E-Print Network [OSTI]

    Ghosh, Somnath

    2012-01-01

    cavities to improve the solar cell efficiency. I have alsocould improve the solar cell efficiency. The second part isfor fabricating high-efficiency solar cell. Traditionally,

  20. Photonic Design: From Fundamental Solar Cell Physics to Computational Inverse Design

    E-Print Network [OSTI]

    Miller, Owen Dennis

    2012-01-01

    I The Physics of High-Efficiency Solar Cells 2 Luminescentint , on theoretical solar cell efficiency. The shortfall isjunction, flat-plate solar cell efficiency records over

  1. Theory of Current Transients in Planar Semiconductor Devices: Insights and Applications to Organic Solar Cells

    E-Print Network [OSTI]

    Hawks, SA; Finck, BY; Schwartz, BJ

    2015-01-01

    Dyakonov, Organic solar cell efficiencies under the aspectfor low-cost, high-efficiency solar cells, J. Phys. Chem.dependent efficiencies of organic bulk heterojunction solar

  2. Improved high temperature solar absorbers for use in Concentrating Solar Power central receiver applications.

    SciTech Connect (OSTI)

    Stechel, Ellen Beth; Ambrosini, Andrea; Hall, Aaron Christopher; Lambert, Timothy L.; Staiger, Chad Lynn; Bencomo, Marlene

    2010-09-01

    Concentrating solar power (CSP) systems use solar absorbers to convert the heat from sunlight to electric power. Increased operating temperatures are necessary to lower the cost of solar-generated electricity by improving efficiencies and reducing thermal energy storage costs. Durable new materials are needed to cope with operating temperatures >600 C. The current coating technology (Pyromark High Temperature paint) has a solar absorptance in excess of 0.95 but a thermal emittance greater than 0.8, which results in large thermal losses at high temperatures. In addition, because solar receivers operate in air, these coatings have long term stability issues that add to the operating costs of CSP facilities. Ideal absorbers must have high solar absorptance (>0.95) and low thermal emittance (<0.05) in the IR region, be stable in air, and be low-cost and readily manufacturable. We propose to utilize solution-based synthesis techniques to prepare intrinsic absorbers for use in central receiver applications.

  3. Efficient Solar Concentrators: Affordable Energy from Water and Sunlight

    SciTech Connect (OSTI)

    2010-01-01

    Broad Funding Opportunity Announcement Project: Teledyne is developing a liquid prism panel that tracks the position of the sun to help efficiently concentrate its light onto a solar cell to produce power. Typically, solar tracking devices have bulky and expensive mechanical moving parts that require a lot of power and are often unreliable. Teledyne’s liquid prism panel has no bulky and heavy supporting parts—instead it relies on electrowetting. Electrowetting is a process where an electric field is applied to the liquid to control the angle at which it meets the sunlight above and to control the angle of the sunlight to the focusing lensthe more direct the angle to the focusing lens, the more efficiently the light can be concentrated to solar panels and converted into electricity. This allows the prism to be tuned like a radio to track the sun across the sky and steer sunlight into the solar cell without any moving mechanical parts. This process uses very little power and requires no expensive supporting hardware or moving parts, enabling efficient and quiet rooftop operation for integration into buildings.

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

    E-Print Network [OSTI]

    Armstrong, Paul Barber

    2010-01-01

    results in a 50% improvement in solar cell efficiency. Theimprovement in performance over previously reported P3HT:PDI solar cells.solar cells. However, not all the PL is quenched, indicating that additional improvement

  5. Techniques for Maximizing Efficiency of Solar Energy Harvesting Systems (Invited Paper)

    E-Print Network [OSTI]

    Shinozuka, Masanobu

    Techniques for Maximizing Efficiency of Solar Energy Harvesting Systems (Invited Paper) Pai H requiring battery replacement. This paper ex- amines technical issues with solar energy harvesting. First power point tracking, energy harvest- ing, solar panel, photovoltaic cell, supercapacitor, ultracapac

  6. Efficient solar anti-neutrino production in random magnetic fields

    E-Print Network [OSTI]

    O. G. Miranda; T. I. Rashba; A. I. Rez; J. W. F. Valle

    2004-05-12

    We have shown that the electron anti-neutrino appearance in the framework of the spin flavor conversion mechanism is much more efficient in the case of neutrino propagation through random than regular magnetic field. This result leads to much stronger limits on the product of the neutrino transition magnetic moment and the solar magnetic field based on the recent KamLAND data. We argue that the existence of the random magnetic fields in the solar convective zone is a natural sequence of the convective zone magnetic field evolution.

  7. High Energy Particles in the Solar Corona

    E-Print Network [OSTI]

    A. Widom; Y. N. Srivastava; L. Larsen

    2008-04-16

    Collective Ampere law interactions producing magnetic flux tubes piercing through sunspots into and then out of the solar corona allow for low energy nuclear reactions in a steady state and high energy particle reactions if a magnetic flux tube explodes in a violent event such as a solar flare. Filamentous flux tubes themselves are vortices of Ampere currents circulating around in a tornado fashion in a roughly cylindrical geometry. The magnetic field lines are parallel to and largely confined within the core of the vortex. The vortices may thereby be viewed as long current carrying coils surrounding magnetic flux and subject to inductive Faraday and Ampere laws. These laws set the energy scales of (i) low energy solar nuclear reactions which may regularly occur and (ii) high energy electro-weak interactions which occur when magnetic flux coils explode into violent episodic events such as solar flares or coronal mass ejections.

  8. Estimating the Cost and Energy Efficiency of a Solar Water Heater...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    the Cost and Energy Efficiency of a Solar Water Heater March 2, 2015 - 3:09pm Addthis Solar water heaters are more efficient the gas or electric heaters. | Chart credit ENERGY...

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

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (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...

  10. Nanoscale Imaging of Photocurrent 2 and Efficiency in CdTe Solar...

    Office of Scientific and Technical Information (OSTI)

    Nanoscale Imaging of Photocurrent 2 and Efficiency in CdTe Solar Cells. Citation Details In-Document Search Title: Nanoscale Imaging of Photocurrent 2 and Efficiency in CdTe Solar...

  11. Advanced Review High efficiency photovoltaics: on

    E-Print Network [OSTI]

    Delaware, University of

    price and its relation to market electricity sales price. The current gap between PV energy price the research and development opportunities for high-efficiency PV and projects the required efficiency-priceAdvanced Review High efficiency photovoltaics: on the way to becoming a major electricity source

  12. High Efficiency Fans and High Efficiency Electrical Motors 

    E-Print Network [OSTI]

    Breedlove, C. W.

    1989-01-01

    operates from 800 hours to 1500 hours per year or 15% of the year. Sixty percent of the connected horsepower is operating pneumatic air fans. These pneumatic fans transport the seed cotton, cotton lint, cottonseed and cotton trash throughout... efficiency will be consistent and ongoing. Since pneumat cs use 60% of the total power consumed in a cotton gin it seemed the most likely pace to improve efficiency. Each fan's sys em was redesigned and engineered. Not on y were old inefficient fans...

  13. Efficiency enhancement of luminescent solar concentrations for photovoltaic technologies

    E-Print Network [OSTI]

    Wang, Chunhua

    2011-01-01

    glass-?lms. Solar Energy Materials and Solar Cells, 33(4):concentrator. Solar Energy Materials and Solar Cells, 93(8):concentrator. Solar Energy Materials and Solar Cells, 91(1):

  14. DISSERTATION Investigation of Spatial Variations in Collection Efficiency of Solar Cells

    E-Print Network [OSTI]

    Sites, James R.

    DISSERTATION Investigation of Spatial Variations in Collection Efficiency of Solar Cells Submitted BY JASON F. HILTNER ENTITLED INVESTIGATION OF SPATIAL VARIATIONS IN COLLECTION EFFICIENCY OF SOLAR CELLS OF SOLAR CELLS In an effort to investigate spatial variations in solar cells, an apparatus which is capable

  15. Toward a Low-CarMunicipal Financing for Energy Efficiency and Solar Power

    E-Print Network [OSTI]

    Kammen, Daniel M.

    Toward a Low-CarMunicipal Financing for Energy Efficiency and Solar Power By Merrian C. Fuller, such as improving energy efficiency and add- ing solar photovoltaics (PV) and solar thermal systems to buildings Berkeley to address this barrier by making financing for solar power installations and energy

  16. 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

    SciTech Connect (OSTI)

    Fatemi, H.

    2012-07-01

    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.

  17. NCTCOG Solar Ready II Project: Clean Air Through Energy Efficiency 

    E-Print Network [OSTI]

    Clark,L.

    2014-01-01

    an sa s Id ah o K an sa s M is si ss ip p i W yo m in g O kl ah o m a N eb ra sk a A la sk a N o rt h D ak o ta So u th D ak o ta M e ga w at ts Installed Capacity (MW) 2013 2% of US Capacity Source: U.S. Solar Market Trends 2013 8 ESL-KT-14... Installed Capacity 9 ESL-KT-14-11-12 CATEE 2014: Clean Air Through Efficiency Conference, Dallas, Texas Nov. 18-20 Plano Solar Advocates - Solarize Plano 2013-2014 Results Measure Target Actual 2013 Total Initial Enrollment 20 200+ Contracts Signed...

  18. Efficiency enhancement of luminescent solar concentrations for photovoltaic technologies

    E-Print Network [OSTI]

    Wang, Chunhua

    2011-01-01

    for generating low-cost solar power, LSC development facesand lowering the cost, luminescent solar concentrations (cells. Using solar concentrators, the cost of solar energy

  19. Efficiency enhancement of luminescent solar concentrations for photovoltaic technologies

    E-Print Network [OSTI]

    Wang, Chunhua

    2011-01-01

    1.1 Solar Energy . . . . . . . . .Ho?mann. Photovoltaic Solar Energy Gen- eration. Opticalon ?uorescent glass-?lms. Solar Energy Materials and Solar

  20. NANOCOMPOSITE ENABLED SENSITIZED SOLAR CELL

    E-Print Network [OSTI]

    Phuyal, Dibya

    2012-01-01

    W. , Dunlop, E.D. Solar Cell efficiency tables (version 38).Grätzel. A Low-Cost, High-Efficiency Solar Cell Based on Dyeand E.D. Dunlop. Solar Cell efficiency tables (version 38).

  1. Technology Development for High Efficiency Clean Diesel Engines...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    High Efficiency Clean Diesel Engines and a Pathway to 50% Thermal Efficiency Technology Development for High Efficiency Clean Diesel Engines and a Pathway to 50% Thermal Efficiency...

  2. High efficiency turbine blade coatings.

    SciTech Connect (OSTI)

    Youchison, Dennis L.; Gallis, Michail A.

    2014-06-01

    The development of advanced thermal barrier coatings (TBCs) of yttria stabilized zirconia (YSZ) that exhibit lower thermal conductivity through better control of electron beam - physical vapor deposition (EB-PVD) processing is of prime interest to both the aerospace and power industries. This report summarizes the work performed under a two-year Lab-Directed Research and Development (LDRD) project (38664) to produce lower thermal conductivity, graded-layer thermal barrier coatings for turbine blades in an effort to increase the efficiency of high temperature gas turbines. This project was sponsored by the Nuclear Fuel Cycle Investment Area. Therefore, particular importance was given to the processing of the large blades required for industrial gas turbines proposed for use in the Brayton cycle of nuclear plants powered by high temperature gas-cooled reactors (HTGRs). During this modest (~1 full-time equivalent (FTE)) project, the processing technology was developed to create graded TBCs by coupling ion beam-assisted deposition (IBAD) with substrate pivoting in the alumina-YSZ system. The Electron Beam - 1200 kW (EB-1200) PVD system was used to deposit a variety of TBC coatings with micron layered microstructures and reduced thermal conductivity below 1.5 W/m.K. The use of IBAD produced fully stoichiometric coatings at a reduced substrate temperature of 600 oC and a reduced oxygen background pressure of 0.1 Pa. IBAD was also used to successfully demonstrate the transitioning of amorphous PVD-deposited alumina to the -phase alumina required as an oxygen diffusion barrier and for good adhesion to the substrate Ni2Al3 bondcoat. This process replaces the time consuming thermally grown oxide formation required before the YSZ deposition. In addition to the process technology, Direct Simulation Monte Carlo plume modeling and spectroscopic characterization of the PVD plumes were performed. The project consisted of five tasks. These included the production of layered periodic microstructures in the coating, the Direct Simulation Monte Carlo (DSMC) modeling of particle transport in the PVD plume, functional graded layer development, the deposition of all layers to form a complete coating, and materials characterization including thermal testing. Ion beam-assisted deposition, beam sharing through advanced digital rastering, substrate pivoting, hearth calorimetry, infrared imaging, fiber optic-enabled optical emission spectroscopy and careful thermal management were used to achieve all the milestones outlined in the FY02 LDRD proposal.

  3. Highly Efficient Coherent Raman Generation 

    E-Print Network [OSTI]

    Hua, Xia

    2014-08-04

    explore detection and sensing applications, and achieve further improvement of efficiency by using field enhancement due to surface plasmon resonances in aggregates of gold nanoparticles. By scanning the time delay of the probe pulse, we demonstrate a new...

  4. The mission of the UC Davis Solar Collaborative is simple: to find ways to make solar cells more efficient. Even in theory, the efficiency of conventional solar cells is limited to a disappointing 31%. However, this limit is based

    E-Print Network [OSTI]

    solar photon excites only a single electron. A recent breakthrough showed that one photon may exciteMission The mission of the UC Davis Solar Collaborative is simple: to find ways to make solar cells more efficient. Even in theory, the efficiency of conventional solar cells is limited

  5. High Energy Efficiency Air Conditioning

    SciTech Connect (OSTI)

    Edward McCullough; Patrick Dhooge; Jonathan Nimitz

    2003-12-31

    This project determined the performance of a new high efficiency refrigerant, Ikon B, in a residential air conditioner designed to use R-22. The refrigerant R-22, used in residential and small commercial air conditioners, is being phased out of production in developed countries beginning this year because of concerns regarding its ozone depletion potential. Although a replacement refrigerant, R-410A, is available, it operates at much higher pressure than R-22 and requires new equipment. R-22 air conditioners will continue to be in use for many years to come. Air conditioning is a large part of expensive summer peak power use in many parts of the U.S. Previous testing and computer simulations of Ikon B indicated that it would have 20 - 25% higher coefficient of performance (COP, the amount of cooling obtained per energy used) than R-22 in an air-cooled air conditioner. In this project, a typical new R-22 residential air conditioner was obtained, installed in a large environmental chamber, instrumented, and run both with its original charge of R-22 and then with Ikon B. In the environmental chamber, controlled temperature and humidity could be maintained to obtain repeatable and comparable energy use results. Tests with Ikon B included runs with and without a power controller, and an extended run for several months with subsequent analyses to check compatibility of Ikon B with the air conditioner materials and lubricant. Baseline energy use of the air conditioner with its original R-22 charge was measured at 90 deg F and 100 deg F. After changeover to Ikon B and a larger expansion orifice, energy use was measured at 90 deg F and 100 deg F. Ikon B proved to have about 19% higher COP at 90 deg F and about 26% higher COP at 100 deg F versus R-22. Ikon B had about 20% lower cooling capacity at 90 deg F and about 17% lower cooling capacity at 100 deg F versus R-22 in this system. All results over multiple runs were within 1% relative standard deviation (RSD). All of these values agree well with previous results and computer simulations of Ikon B performance versus R-22. The lower cooling capacity of Ikon B is not a concern unless a particular air conditioner is near its maximum cooling capacity in application. Typically, oversized A/C systems are installed by contractors to cover contingencies. In the extended run with Ikon B, which lasted about 4.5 months at 100 deg F ambient temperature and 68% compressor on time, the air conditioner performed well with no significant loss of energy efficiency. Post-run analysis of the refrigerant, compressor lubricant oil, compressor, compressor outlet tubing, and the filter/dryer showed minor effects but nothing that was considered significant. The project was very successful. All objectives were achieved, and the performance of Ikon B indicates that it can easily be retrofitted into R-22 air conditioners to give 15 - 20% energy savings and a 1 - 3 year payback of retrofit costs depending on location and use. Ikon B has the potential to be a successful commercial product.

  6. Band structure engineering for solar energy applications: ZnO1-xSex films and devices

    E-Print Network [OSTI]

    Mayer, Marie Annette

    2012-01-01

    material properties. Solar efficiencies are limited by bandfor achieving high efficiency solar cells include utilizingconditions, the solar-to-hydrogen efficiency (STH) can be

  7. Project Profile: High-Temperature Solar Selective Coating Development...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Solar Selective Coating Development for Power Tower Receivers Project Profile: High-Temperature Solar Selective Coating Development for Power Tower Receivers Sandia National...

  8. High Efficiency Fuel Reactivity Controlled Compression Ignition...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    High Efficiency Fuel Reactivity Controlled Compression Ignition Combustion An optimized dual-fuel PCCI concept, RCCI, is proposed. deer10reitz.pdf More Documents & Publications...

  9. Nanostructured Thermoelectric Materials and High Efficiency Power...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Nanostructured Thermoelectric Materials and High Efficiency Power Generation Modules Home Author: T. Hogan, A. Downey, J. Short, S. D. Mahanti, H. Schock, E. Case Year: 2007...

  10. High Efficiency Modular Chemical Processes (HEMCP)

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    - ADVANCED MANUFACTURING OFFICE High Efficiency Modular Chemical Processes (HEMCP) Modular Process Intensification Framework for R&D Targets Advanced Manufacturing Office...

  11. Building Energy-Efficiency Best Practice Policies and Policy Packages

    E-Print Network [OSTI]

    Levine, Mark

    2014-01-01

    as photovoltaics (PV) and solar water heaters, and directheat pumps, solar water heaters, and solar PV systems. Theshading measures, solar water heaters, and high efficiency

  12. Highly Mismatched Alloys for Intermediate Band Solar Cells

    SciTech Connect (OSTI)

    Walukiewicz, W.; Yu, K.M.; Wu, J.; Ager III, J.W.; Shan, W.; Scrapulla, M.A.; Dubon, O.D.; Becla, P.

    2005-03-21

    It has long been recognized that the introduction of a narrow band of states in a semiconductor band gap could be used to achieve improved power conversion efficiency in semiconductor-based solar cells. The intermediate band would serve as a ''stepping stone'' for photons of different energy to excite electrons from the valence to the conduction band. An important advantage of this design is that it requires formation of only a single p-n junction, which is a crucial simplification in comparison to multijunction solar cells. A detailed balance analysis predicts a limiting efficiency of more than 50% for an optimized, single intermediate band solar cell. This is higher than the efficiency of an optimized two junction solar cell. Using ion beam implantation and pulsed laser melting we have synthesized Zn{sub 1-y}Mn{sub y}O{sub x}Te{sub 1-x} alloys with x<0.03. These highly mismatched alloys have a unique electronic structure with a narrow oxygen-derived intermediate band. The width and the location of the band is described by the Band Anticrossing model and can be varied by controlling the oxygen content. This provides a unique opportunity to optimize the absorption of solar photons for best solar cell performance. We have carried out systematic studies of the effects of the intermediate band on the optical and electrical properties of Zn{sub 1-y}Mn{sub y}O{sub x}Te{sub 1-x} alloys. We observe an extension of the photovoltaic response towards lower photon energies, which is a clear indication of optical transitions from the valence to the intermediate band.

  13. Black oxide nanoparticles as durable solar absorbing material for high-temperature concentrating solar power system

    E-Print Network [OSTI]

    California at San Diego, University of

    Available online 8 January 2015 Keywords: Concentrating solar power Solar absorber Cobalt oxide Light trapping High temperature a b s t r a c t Concentrating solar power is becoming an increasingly important an increasingly urgent need for human society [1,2]. Concentrating solar power (CSP) systems (or solar thermal sys

  14. High Efficiency Electron-Laser Interactions in Tapered Helical Undulators

    E-Print Network [OSTI]

    Duris, Joseph

    2015-01-01

    Demonstration of high-trapping efficiency and narrow energylaser accelerator for efficient production of high qualityand J. S. Wurtele. High-efficiency extraction of microwave

  15. Path to High Efficiency Gasoline Engine | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Path to High Efficiency Gasoline Engine Path to High Efficiency Gasoline Engine Path to High Efficiency Gasoline Engine deer10johansson.pdf More Documents & Publications Partially...

  16. High Efficiency Broadband Envelope-Tracking Power Amplifiers

    E-Print Network [OSTI]

    Yan, Jonmei Johana

    M. ,   “   Wideband High Efficiency Envelope Tracking PowerPeter  M. ,  “High-Efficiency Envelope Tracking High PowerMemory! DPD! Drain! Efficiency! (%)! Gain! (dB)! Output!

  17. TJ Solar Cell (GaInP/GaAs/Ge Ultrahigh-Efficiency Solar Cells

    SciTech Connect (OSTI)

    Friedman, Daniel

    2002-04-17

    This talk will discuss recent developments in III-V multijunction photovoltaic technology which have led to the highest-efficiency solar cells ever demonstrated. The relationship between the materials science of III-V semiconductors and the achievement of record solar cell efficiencies will be emphasized. For instance, epitaxially-grown GAInP has been found to form a spontaneously-ordered GaP/InP (111) superlattice. This ordering affects the band gap of the material, which in turn affects the design of solar cells which incorporate GaInP. For the next generation of ultrahigh-efficiency III-V solar cells, we need a new semiconductor which is lattice-matched to GaAs, has a band gap of 1 eV, and has long minority-carrier diffusion lengths. Out of a number of candidate materials, the recently-discovered alloy GaInNAs appears to have the greatest promise. This material satisfies the first two criteria, but has to date shown very low diffusion lengths, a problem which is our current focus in the development of these next-generation cells.

  18. The importance of surface texture to high silicon solar cell performance

    SciTech Connect (OSTI)

    Spitzer, M.B.; Bajgar, C.; Keavney, C.J.; Tobin, S.P.

    1984-08-01

    This paper reviews the utilization of surface texture for attainment of high conversion efficiency in Si p/n junction solar cells. Advantages and disadvantages of surface texture are discussed, and recent research on high efficiency ion-implanted cells that demonstrates some important aspects of texture is reviewed. Texture-etched cells with AMI conversion efficiency of 18% are reported and the manner in which use of texture might lead to even higher efficiency is discussed.

  19. U.S. Department of Energy Solar Decathlon: Challenging Students to Build Energy Efficient, Cost-Effective, and Attractive Solar-Powered Houses

    SciTech Connect (OSTI)

    Simon, J.

    2012-01-01

    The U.S. Department of Energy Solar Decathlon challenges collegiate teams to design, build, and operate solar-powered houses that are cost-effective, energy-efficient, and attractive. The winner of the competition is the team that best blends affordability, consumer appeal, and design excellence with optimal energy production and maximum efficiency. The paper discusses the solutions developed for the event. We believe that the solutions implemented for Solar Decathlon 2011 represent current trends and that by analyzing, critiquing, and exposing the solutions pursued, the industry can become better suited to address challenges of the future. Constructing a solar community using high-efficiency design and unique materials while remaining code compliant, safe, and effective results in solutions that are market relevant, important, and interesting to the industry as a whole.

  20. Multiscale approaches to high efficiency photovoltaics

    E-Print Network [OSTI]

    Connolly, J P; Mencaraglia, D; Rimada, Julio C; Nejim, Ahmed; Sanchez, G

    2015-01-01

    While renewable energies are achieving parity around the globe, efforts to reach higher solar cell efficiencies becomes ever more difficult as they approach the limiting efficiency. The so-called third generation concepts attempt to break this limit through a combination of novel physical processes and new materials and concepts in organic and inorganic systems. Some examples of semi-empirical modelling in the field are reviewed, in particular for multispectral solar cells on silicon (french ANR project MULTISOLSI). Their achievements are outlined, and the limits of these approaches shown. This introduces the main topic of this contribution, which is the use of multiscale experimental and theoretical techniques to go beyond the semi-empirical understanding of these systems. This approach has already led to great advances at modelling which have led to modelling software which is widely known. Yet a survey of the topic reveals a fragmentation of efforts across disciplines, firstly, such as organic and inorgani...

  1. Promising Technology: High-Efficiency Rooftop Units

    Broader source: Energy.gov [DOE]

    High-efficiency rooftop air conditioning units (RTUs) can significantly reduce heating, cooling, and ventilation energy consumption. High efficiency RTUs incorporate variable speed controls to minimize fan and compressor energy while capturing and reusing heat, cold, and humidity from a building’s exhaust air.

  2. Monolithically interconnected GaAs solar cells: A new interconnection technology for high voltage solar cell output

    SciTech Connect (OSTI)

    Dinetta, L.C.; Hannon, M.H.

    1995-10-01

    Photovoltaic linear concentrator arrays can benefit from high performance solar cell technologies being developed at AstroPower. Specifically, these are the integration of thin GaAs solar cell and epitaxial lateral overgrowth technologies with the application of monolithically interconnected solar cell (MISC) techniques. This MISC array has several advantages which make it ideal for space concentrator systems. These are high system voltage, reliable low cost monolithically formed interconnections, design flexibility, costs that are independent of array voltage, and low power loss from shorts, opens, and impact damage. This concentrator solar cell will incorporate the benefits of light trapping by growing the device active layers over a low-cost, simple, PECVD deposited silicon/silicon dioxide Bragg reflector. The high voltage-low current output results in minimal 12R losses while properly designing the device allows for minimal shading and resistance losses. It is possible to obtain open circuit voltages as high as 67 volts/cm of solar cell length with existing technology. The projected power density for the high performance device is 5 kW/m for an AMO efficiency of 26% at 1 5X. Concentrator solar cell arrays are necessary to meet the power requirements of specific mission platforms and can supply high voltage power for electric propulsion systems. It is anticipated that the high efficiency, GaAs monolithically interconnected linear concentrator solar cell array will enjoy widespread application for space based solar power needs. Additional applications include remote man-portable or ultra-light unmanned air vehicle (UAV) power supplies where high power per area, high radiation hardness and a high bus voltage or low bus current are important. The monolithic approach has a number of inherent advantages, including reduced cost per interconnect and increased reliability of array connections. There is also a high potential for a large number of consumer products.

  3. Efficiency enhancement of luminescent solar concentrations for photovoltaic technologies

    E-Print Network [OSTI]

    Wang, Chunhua

    2011-01-01

    ing ?uorescent dye for solar energy conversion based on aimprove the the solar energy conversion e?ciency. Outputcheaper solar energy concentration and conversion methods,

  4. Efficiency enhancement of luminescent solar concentrations for photovoltaic technologies

    E-Print Network [OSTI]

    Wang, Chunhua

    2011-01-01

    by one-sun solar simulator. . . . . . . . . . . . . . .two kinds of solar concentrators, one is based on geomet-to utilize the whole solar spectrum, one of the methods is

  5. Thermodynamics, Entropy, Information and the Efficiency of Solar Cells

    E-Print Network [OSTI]

    Abrams, Zeev R.

    2012-01-01

    of analytical expressions for solar cell fill factors.Solar Cells 7, 31. A. Luque and V. Andreev, Concentratorenergy gap terrestrial solar cells. J. Appl. Phys. 51,

  6. Design of hybrid nanoheterostructure systems for enhanced quantum and solar conversion efficiencies in dye-sensitized solar cells

    SciTech Connect (OSTI)

    K?l?ç, Bayram E-mail: kbayramkilic@gmail.com; Telli, Hakan; Ba?aran, Ali; Pirge, Gursev; Tüzemen, Sebahattin

    2015-04-07

    Dye sensitized solar cells (DSSCs) with an innovative design involving controlled-morphology vertically aligned (VA) ZnO nanowires within mesoporous TiO{sub 2} structures with ultrahigh surface area for implementation as photoanodes are herein reported. Although TiO{sub 2} nanostructures exhibit excellent power conversion efficiency, the electron transport rate is low owing to low electron mobility. To overcome this, ZnO nanowires with high electron mobility have been investigated as potential candidates for photoanodes. However, the power conversion efficiency of ZnO nanowires is still lower than that of TiO{sub 2} owing to their low internal surface area. Consequently, in this work, vertical growth of ZnO nanowires within mesoporous TiO{sub 2} structures is carried out to increase their solar power conversion efficiency. The photovoltaic performance of solar cells using ZnO nanowires, mesoporous TiO{sub 2}, and TiO{sub 2}/ZnO hybrid structures are compared. The VA TiO{sub 2}/ZnO hybrid structures are found to provide direct electron transfer compared with the tortuous pathway of zero-dimensional nanostructures, resulting in an increased conversion efficiency. It is demonstrated that the light scattering of the photoanode film is increased and electron recombination is decreased when an appropriate amount of mesoporous TiO{sub 2} is used as a substrate for ZnO nanowires. The DSSC fabricated with the TiO{sub 2}/ZnO hybrid photoanode prepared with 15.8?wt. % TiO{sub 2} showed the highest conversion efficiency of 7.30%, approximately 5%, 18%, and 40% higher than that of DSSCs fabricated with 3.99?wt. % TiO{sub 2}, pure TiO{sub 2}, and pure ZnO photoanodes, respectively.

  7. Solar energy conversion via hot electron internal photoemission in metallic nanostructures: Efficiency estimates

    SciTech Connect (OSTI)

    Leenheer, Andrew J.; Narang, Prineha; Atwater, Harry A.; Lewis, Nathan S.

    2014-04-07

    Collection of hot electrons generated by the efficient absorption of light in metallic nanostructures, in contact with semiconductor substrates can provide a basis for the construction of solar energy-conversion devices. Herein, we evaluate theoretically the energy-conversion efficiency of systems that rely on internal photoemission processes at metal-semiconductor Schottky-barrier diodes. In this theory, the current-voltage characteristics are given by the internal photoemission yield as well as by the thermionic dark current over a varied-energy barrier height. The Fowler model, in all cases, predicts solar energy-conversion efficiencies of <1% for such systems. However, relaxation of the assumptions regarding constraints on the escape cone and momentum conservation at the interface yields solar energy-conversion efficiencies as high as 1%–10%, under some assumed (albeit optimistic) operating conditions. Under these conditions, the energy-conversion efficiency is mainly limited by the thermionic dark current, the distribution of hot electron energies, and hot-electron momentum considerations.

  8. Efficient solar cooling: first ever non-tracking solar collectors powering a double effect absorption chiller

    E-Print Network [OSTI]

    Poiry, Heather Marie

    2011-01-01

    Based Performance Analysis of a Solar Absorption Cooling andExperimental Investigation of a Solar Adsorption ChillerKreith, Jan F. Kreider. "Solar Cooling." Principles of Solar

  9. FINE-LINE PRINTED 5 BUSBAR PERC SOLAR CELLS WITH CONVERSION EFFICIENCIES Thorsten Dullweber1

    E-Print Network [OSTI]

    efficiencies of full-area Al- BSF solar cells are indicated as well. Passivated Emitter and Rear Cells (PERCFINE-LINE PRINTED 5 BUSBAR PERC SOLAR CELLS WITH CONVERSION EFFICIENCIES BEYOND 21% ThorstenH, Berthelsdorfer Str. 111 A, 09599 Freiberg, Germany ABSTRACT: We evaluate industrial-type PERC solar cells

  10. Solar power conversion efficiency in modulated silicon nanowire photonic Alexei Deinega and Sajeev John

    E-Print Network [OSTI]

    John, Sajeev

    Solar power conversion efficiency in modulated silicon nanowire photonic crystals Alexei Deinega://jap.aip.org/about/rights_and_permissions #12;Solar power conversion efficiency in modulated silicon nanowire photonic crystals Alexei Deinegaa that using only 1 lm of silicon, sculpted in the form of a modulated nanowire photonic crystal, solar power

  11. Toward a Low-CarMunicipal Financing for Energy Efficiency and Solar Power

    E-Print Network [OSTI]

    Kammen, Daniel M.

    Toward a Low-CarMunicipal Financing for Energy Efficiency and Solar Power By Merrian C. Fuller of the Inter- governmental Panel on Climate Change (IPCC). Thus far much of the effort has been focused, such as improving energy efficiency and add- ing solar photovoltaics (PV) and solar thermal systems to buildings

  12. The role of three-dimensional morphology on the efficiency of hybrid polymer solar cells

    E-Print Network [OSTI]

    Schmidt, Volker

    1 The role of three-dimensional morphology on the efficiency of hybrid polymer solar cells Stefan D.a.j.janssen@tue.nl #12;2 Abstract: The efficiency of polymer solar cells critically depends on the intimacy of mixing and quantitative correlation between solar cell performance, photophysical data and the three

  13. Efficient light harvesting in multiple-device stacked structure for polymer solar cells

    E-Print Network [OSTI]

    Efficient light harvesting in multiple-device stacked structure for polymer solar cells Vishal structure of polymer solar cells for efficient light harvesting. Two polymer photovoltaic cells are stacked harvesting has been demonstrated for organic solar cells uti- lizing tandem structure.11,12 However

  14. METAL BLACKS AS SCATTERING CENTERS TO INCREASE THE EFFICIENCY OF THIN FILM SOLAR CELLS

    E-Print Network [OSTI]

    Peale, Robert E.

    METAL BLACKS AS SCATTERING CENTERS TO INCREASE THE EFFICIENCY OF THIN FILM SOLAR CELLS by DEEP R surface of thin-film solar cells to improve efficiency. The principle is that scattering, which film solar cell. The particular types of particles investigated here are known as "metal-black", well

  15. High Rate Laser Pitting Technique for Solar Cell Texturing

    SciTech Connect (OSTI)

    Hans J. Herfurth; Henrikki Pantsar

    2013-01-10

    High rate laser pitting technique for solar cell texturing Efficiency of crystalline silicon solar cells can be improved by creating a texture on the surface to increase optical absorption. Different techniques have been developed for texturing, with the current state-of-the-art (SOA) being wet chemical etching. The process has poor optical performance, produces surfaces that are difficult to passivate or contact and is relatively expensive due to the use of hazardous chemicals. This project shall develop an alternative process for texturing mc-Si using laser micromachining. It will have the following features compared to the current SOA texturing process: -Superior optical surfaces for reduced front-surface reflection and enhanced optical absorption in thin mc-Si substrates -Improved surface passivation -More easily integrated into advanced back-contact cell concepts -Reduced use of hazardous chemicals and waste treatment -Similar or lower cost The process is based on laser pitting. The objective is to develop and demonstrate a high rate laser pitting process which will exceed the rate of former laser texturing processes by a factor of ten. The laser and scanning technologies will be demonstrated on a laboratory scale, but will use inherently technologies that can easily be scaled to production rates. The drastic increase in process velocity is required for the process to be implemented as an in-line process in PV manufacturing. The project includes laser process development, development of advanced optical systems for beam manipulation and cell reflectivity and efficiency testing. An improvement of over 0.5% absolute in efficiency is anticipated after laser-based texturing. The surface textures will be characterized optically, and solar cells will be fabricated with the new laser texturing to ensure that the new process is compatible with high-efficiency cell processing. The result will be demonstration of a prototype process that is suitable for scale-up to a production tool and process. The developed technique will have an reducing impact on product pricing. As efficiency has a substantial impact on the economics of solar cell production due to the high material cost content; in essence, improved efficiency through cost-effective texturing reduces the material cost component since the product is priced in terms of $/W. The project is a collaboration between Fraunhofer USA, Inc. and a c-Si PV manufacturer.

  16. Thermal Strategies for High Efficiency Thermoelectric Power Generation...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Strategies for High Efficiency Thermoelectric Power Generation Thermal Strategies for High Efficiency Thermoelectric Power Generation Developing integrated TE system configurations...

  17. Efficiency of a solar collector with internal boiling

    SciTech Connect (OSTI)

    Neeper, D.A.

    1986-01-01

    The behavior of a solar collector with a boiling fluid is analyzed to provide a simple algebraic model for future systems simulations, and to provide guidance for testing. The efficiency equation is developed in a form linear in the difference between inlet and saturation (boiling) temperatures, whereas the expression upon which ASHRAE Standard 109P is based utilizes the difference between inlet and ambient temperatures. The coefficient of the revised linear term is a weak function of collector parameters, weather, and subcooling of the working fluid. For a glazed flat-plate collector with metal absorber, the coefficient is effectively constant. Therefore, testing at multiple values of insolation and subcooling, as specified by ASHRAE 109P, should not be necessary for most collectors. The influences of collector properties and operating conditions on efficiency are examined.

  18. HIGH-POWER, HIGH-EFFICIENCY FELS

    E-Print Network [OSTI]

    Sessler, A.M.

    2008-01-01

    M. Kumada, "Scaling of the FEL-ID Equations", ELF Note 128,Instability in a High-power, Short- Wavelength FEL", Proc.of the Ninth FEL" Conference, Williamsburg (1988), and

  19. Maximizing Efficiency of Solar-Powered Systems by Load Matching

    E-Print Network [OSTI]

    Shinozuka, Masanobu

    energy. However, solar powered sys- tems must also consider the output level of the solar panel for power be counterproductive. Another problem that is of particular importance to solar pan- els is load matching. Solar panels is around 0.7­1.2, solar panels have a much larger Ri value as a function of the solar output and current

  20. Thermal Conductivity Enhancement of High Temperature Phase Change Materials for Concentrating Solar Power Plant Applications

    E-Print Network [OSTI]

    Roshandell, Melina

    2013-01-01

    materials (PCM) in solar thermal concentrating technologyeffective and efficient solar thermal electricity generatorbeen considered for solar thermal energy storages. These are

  1. Technology Development for Light Duty High Efficient Diesel Engines...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Light Duty High Efficient Diesel Engines Technology Development for Light Duty High Efficient Diesel Engines Improve the efficiency of diesel engines for light duty applications...

  2. High concentration low wattage solar arrays and their applications

    SciTech Connect (OSTI)

    Hoffmann, R.; OGallagher, J.; Winston, R.

    1997-02-01

    Midway Labs currently produces a 335x concentrator module that has reached as high as 19{percent} active area efficiency in production. The current production module uses the single crystal silicon back contact SunPower cell. The National Renewable Energy Lab has developed a multi junction cell using GalnP/GaAs technologies. The high efficiency ({gt}30{percent}) and high cell voltage offer an opportunity for Midway Labs to develop a tracking concentrator module that will provide 24 volts in the 140 to 160 watt range. This voltage and wattage range is applicable to a range of small scale water pumping applications that make up the bulk of water pumping solar panel sales. {copyright} {ital 1997 American Institute of Physics.}

  3. Efficient high density train operations

    DOE Patents [OSTI]

    Gordon, Susanna P. (Oakland, CA); Evans, John A. (Hayward, CA)

    2001-01-01

    The present invention provides methods for preventing low train voltages and managing interference, thereby improving the efficiency, reliability, and passenger comfort associated with commuter trains. An algorithm implementing neural network technology is used to predict low voltages before they occur. Once voltages are predicted, then multiple trains can be controlled to prevent low voltage events. Further, algorithms for managing inference are presented in the present invention. Different types of interference problems are addressed in the present invention such as "Interference. During Acceleration", "Interference Near Station Stops", and "Interference During Delay Recovery." Managing such interference avoids unnecessary brake/acceleration cycles during acceleration, immediately before station stops, and after substantial delays. Algorithms are demonstrated to avoid oscillatory brake/acceleration cycles due to interference and to smooth the trajectories of closely following trains. This is achieved by maintaining sufficient following distances to avoid unnecessary braking/accelerating. These methods generate smooth train trajectories, making for a more comfortable ride, and improve train motor reliability by avoiding unnecessary mode-changes between propulsion and braking. These algorithms can also have a favorable impact on traction power system requirements and energy consumption.

  4. New Funding Boosts Carbon Capture, Solar Energy and High Gas...

    Energy Savers [EERE]

    New Funding Boosts Carbon Capture, Solar Energy and High Gas Mileage Cars and Trucks New Funding Boosts Carbon Capture, Solar Energy and High Gas Mileage Cars and Trucks June 11,...

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

    SciTech Connect (OSTI)

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

    2008-09-02

    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.

  6. Bilayer Polymer Solar Cells with Improved Power Conversion Efficiency and Enhanced Spectrum Coverage

    SciTech Connect (OSTI)

    Kekuda, Dhananjaya [Department of Physics, Manipal Institute of Technology, Manipal University, Manipal, India 576 104 (India); Chu, Chih-Wei [Research Center for Applied Science, Academia Sinica, Taipei, Taiwan 300 13 (China)

    2011-10-20

    We demonstrate the construction of an efficient bilayer polymer solar cell comprising of Poly(3-hexylthiophene)(P3HT) as a p-type semiconductor and asymmetric fullerene (C{sub 70}) as n-type counterparts. The bilayer configuration was very efficient compared to the individual layer performance and it behaved like a regular p-n junction device. The photovoltaic characteristic of the bilayers were studied under AM 1.5 solar radiation and the optimized device parameters are the following: Voc = 0.5V, Jsc = 10.1 mA/cm{sup 2}, FF = 0.60 and power conversion efficiency of 3.6 %. A high fill factor of {approx}0.6 was achieved, which is only slightly reduced at very intense illumination. Balanced mobility between p-and n-layers is achieved which is essential for achieving high device performance. Correlation between the crystallinity, morphology and the transport properties of the active layers is established. The External quantum efficiency (EQE) spectral distribution of the bilayer devices with different processing solvents correlates well with the trends of short circuit current densities (J{sub sc}) measured under illumination. Efficiency of the bilayer devices with rough P3HT layer was found to be about 3 times higher than those with a planar P3HT surface. Hence it is desirable to have a larger grains with a rough surface of P3HT layer for providing larger interfacial area for the exciton dissociation.

  7. Material and Device Analysis for Efficiency Improvement in Epitaxial Crystalline Solar Cells: Cooperative Research and Development Final Report, CRADA Number CRD-11-433

    SciTech Connect (OSTI)

    Sopori, B.

    2014-01-01

    Crystal Solar has a novel approach for producing low-cost, monocrystalline silicon wafers that are capable of yielding high-efficiency solar cells. The approach involves epitaxial growth of the substrate and a proprietary lift-off technology. Crystal Solar will send selected wafers and cells to NREL for characterization and analyses. NREL will apply a variety of techniques to help identify mechanism(s) that limit the cell efficiency and suggest suitable approaches for mitigation.

  8. Effects of Spectral Error in Efficiency Measurements of GaInAs-Based Concentrator Solar Cells

    SciTech Connect (OSTI)

    Osterwald, C. R.; Wanlass, M. W.; Moriarty, T.; Steiner, M. A.; Emery, K. A.

    2014-03-01

    This technical report documents a particular error in efficiency measurements of triple-absorber concentrator solar cells caused by incorrect spectral irradiance -- specifically, one that occurs when the irradiance from unfiltered, pulsed xenon solar simulators into the GaInAs bottom subcell is too high. For cells designed so that the light-generated photocurrents in the three subcells are nearly equal, this condition can cause a large increase in the measured fill factor, which, in turn, causes a significant artificial increase in the efficiency. The error is readily apparent when the data under concentration are compared to measurements with correctly balanced photocurrents, and manifests itself as discontinuities in plots of fill factor and efficiency versus concentration ratio. In this work, we simulate the magnitudes and effects of this error with a device-level model of two concentrator cell designs, and demonstrate how a new Spectrolab, Inc., Model 460 Tunable-High Intensity Pulsed Solar Simulator (T-HIPSS) can mitigate the error.

  9. Organic Tandem Solar Cells: Design and Formation

    E-Print Network [OSTI]

    Chen, Chun-Chao

    2015-01-01

    78-85. F. Dimroth, “ High-efficiency solar cells from III-Vand E. D. Dunlop, ?Solar cell efficiency tables (versionOptimizing the organic solar cell efficiency: Role of the

  10. Multicolor, High Efficiency, Nanotextured LEDs

    SciTech Connect (OSTI)

    Jung Han; Arto Nurmikko

    2011-09-30

    We report on research results in this project which synergize advanced material science approaches with fundamental optical physics concepts pertaining to light-matter interaction, with the goal of solving seminal problems for the development of very high performance light emitting diodes (LEDs) in the blue and green for Solid State Lighting applications. Accomplishments in the duration of the contract period include (i) heteroepitaxy of nitrogen-polar LEDs on sapphire, (ii) heteroepitaxy of semipolar (11{bar 2}2) green LEDs on sapphire, (iii) synthesis of quantum-dot loaded nanoporous GaN that emits white light without phosphor conversion, (iv) demonstration of the highest quality semipolar (11{bar 2}2) GaN on sapphire using orientation-controlled epitaxy, (v) synthesis of nanoscale GaN and InGaN medium, and (vi) development of a novel liftoff process for manufacturing GaN thin-film vertical LEDs. The body of results is presented in this report shows how a solid foundation has been laid, with several noticeable accomplishments, for innovative research, consistent with the stated milestones.

  11. Thermodynamics, Entropy, Information and the Efficiency of Solar Cells

    E-Print Network [OSTI]

    Abrams, Zeev R.

    2012-01-01

    a photovoltaic solar cell is one which produces electricitythe current of the solar cell is one of the main themes ofsingle junction solar cell is one that is thermodynamically

  12. Thermodynamics, Entropy, Information and the Efficiency of Solar Cells

    E-Print Network [OSTI]

    Abrams, Zeev R.

    2012-01-01

    11 th E. C. Photovoltaic Solar Energy Conference, Montreal,of analytical expressions for solar cell fill factors.Solar Cells 7, 31. A. Luque and V. Andreev, Concentrator

  13. Thermodynamics, Entropy, Information and the Efficiency of Solar Cells

    E-Print Network [OSTI]

    Abrams, Zeev R.

    2012-01-01

    materials. The multi-junction solar cell is an obviousmulti-junction cell was envisioned from the outset of solar cellthe solar cell intact (such as the dc, uc or multi- junction

  14. Efficient solar cooling: first ever non-tracking solar collectors powering a double effect absorption chiller

    E-Print Network [OSTI]

    Poiry, Heather Marie

    2011-01-01

    to close the solar valve turn off Natural Gas and switch tonatural gas and using solar thermal energy. There is a solar valve

  15. Efficient solar cooling: first ever non-tracking solar collectors powering a double effect absorption chiller

    E-Print Network [OSTI]

    Poiry, Heather Marie

    2011-01-01

    2004) “Advances in solar thermal electricity technology”.1: Comparison of the pros and cons for various solar thermalof Three Concentrating Solar Thermal Units Designed with

  16. Efficient solar cooling: first ever non-tracking solar collectors powering a double effect absorption chiller

    E-Print Network [OSTI]

    Poiry, Heather Marie

    2011-01-01

    solar energy to the solar thermal collector system was calculated by: Equationenergy equation from equation 4.3 Balance of System Now that the solar

  17. Efficient solar cooling: first ever non-tracking solar collectors powering a double effect absorption chiller

    E-Print Network [OSTI]

    Poiry, Heather Marie

    2011-01-01

    cost effective solar thermal collector capable of producinghow to design a solar thermal collector that could achievedesign and model solar thermal collectors. In 2007 our group

  18. Efficiency enhancement of luminescent solar concentrations for photovoltaic technologies

    E-Print Network [OSTI]

    Wang, Chunhua

    2011-01-01

    are like multi-junction solar cells [GH05]. Fourth, dyes canof the solar spectrum like multi-junction cells to improve

  19. Powering a Home with Just 25 Watts of Solar PV. Super-Efficient Appliances Can Enable Expanded Off-Grid Energy Service Using Small Solar Power Systems

    SciTech Connect (OSTI)

    Phadke, Amol A.; Jacobson, Arne; Park, Won Young; Lee, Ga Rick; Alstone, Peter; Khare, Amit

    2015-04-01

    Highly efficient direct current (DC) appliances have the potential to dramatically increase the affordability of off-grid solar power systems used for rural electrification in developing countries by reducing the size of the systems required. For example, the combined power requirement of a highly efficient color TV, four DC light emitting diode (LED) lamps, a mobile phone charger, and a radio is approximately 18 watts and can be supported by a small solar power system (at 27 watts peak, Wp). Price declines and efficiency advances in LED technology are already enabling rapidly increased use of small off-grid lighting systems in Africa and Asia. Similar progress is also possible for larger household-scale solar home systems that power appliances such as lights, TVs, fans, radios, and mobile phones. When super-efficient appliances are used, the total cost of solar home systems and their associated appliances can be reduced by as much as 50%. The results vary according to the appliances used with the system. These findings have critical relevance for efforts to provide modern energy services to the 1.2 billion people worldwide without access to the electrical grid and one billion more with unreliable access. However, policy and market support are needed to realize rapid adoption of super-efficient appliances.

  20. High-Efficiency Inverter for Photovoltaic Applications

    E-Print Network [OSTI]

    Perreault, Dave

    , photovoltaic power systems, AC module. I. INTRODUCTION A. Motivation and Background The market for roof and associated con- trol method suitable for high efficiency DC to AC grid-tied power conversion. This approach) applications. The topology is based on a series resonant inverter, a high frequency transformer, and a novel

  1. Molecular solution processing of metal chalcogenide thin film solar cells

    E-Print Network [OSTI]

    Yang, Wenbing

    2013-01-01

    S. Guha, High-Efficiency Cu2ZnSnSe4 Solar Cells with a TiNfurther improvement on CZTS solar cells efficiency. Finally,Route to High-Efficiency CZTSSe Thin-film Solar Cells, Proc.

  2. 19.2% Efficient InP Heterojunction Solar Cell with Electron-Selective TiO2 Contact

    E-Print Network [OSTI]

    Javey, Ali

    19.2% Efficient InP Heterojunction Solar Cell with Electron-Selective TiO2 Contact Xingtian Yin for solar energy conversion.20 The most efficient InP solar cells use a homojunction configurationP to form a heterojunction solar cell with an efficiency of 17.4%.23,24 Here, by employing a TiO2 electron

  3. Efficient solar cooling: first ever non-tracking solar collectors powering a double effect absorption chiller

    E-Print Network [OSTI]

    Poiry, Heather Marie

    2011-01-01

    natural gas and using solar thermal energy. There is a solarnatural gas or on solar thermal energy before it will switchavailable solar energy to the solar thermal collector system

  4. The Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) Mission

    E-Print Network [OSTI]

    California at Berkeley, University of

    The Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) Mission R. P. fla B. Dennis, G mission is to investigate the physics of particle acceleration and energy release in solar flares, through-ray/gamma-ray spectroscopy 1. INTRODUCTION The primary scientific objective of the Reuven Ramaty High Energy Solar

  5. Efficiency enhancement of luminescent solar concentrations for photovoltaic technologies

    E-Print Network [OSTI]

    Wang, Chunhua

    2011-01-01

    collectors to harness the energy. Passive solar techniques include orienting a build- ing to the Sun,

  6. High Penetration Solar Distributed Generation Study on Oahu ...

    Office of Environmental Management (EM)

    on Oahu High Penetration Solar Distributed Generation Study on Oahu The rooftop solar PV on Hawai'i's Mauna Lani Bay Hotel generates 75 kW of electricity. Photo from...

  7. High Performance Solar Control Office Windows

    E-Print Network [OSTI]

    King, William J.

    2011-01-01

    windows for solar heat transmission and retention forheat retention capability without seriously affecting their transmission

  8. Optimization of the absorption efficiency of an amorphous-silicon thin-film tandem solar cell

    E-Print Network [OSTI]

    to bring down the cost of photovoltaic (PV) solar cells has gained huge momentum, and many strategiesOptimization of the absorption efficiency of an amorphous-silicon thin-film tandem solar cell-wave approach was used to compute the plane-wave absorptance of a thin-film tandem solar cell with a metallic

  9. Nanodome Solar Cells with Efficient Light Management and Self-Cleaning

    E-Print Network [OSTI]

    Fan, Shanhui

    Nanodome Solar Cells with Efficient Light Management and Self-Cleaning Jia Zhu, Ching-Mei Hsu 94305 ABSTRACT Here for the first time, we demonstrate novel nanodome solar cells, which have periodic and enhance absorption over a broad spectral range. Nanodome solar cells with only a 280 nm thick hydrogenated

  10. Improving the efficiency of water splitting in dye-sensitized solar cells by using a biomimetic

    E-Print Network [OSTI]

    Improving the efficiency of water splitting in dye-sensitized solar cells by using a biomimetic studied this problem in dye-sensitized solar cells where a molecular dye and a porous TiO2 electrode act 16802; b Department of Chemistry and Biochemistry and Center for Bioinspired Solar Fuel Production

  11. Enhanced efficiency of thin film solar cells using a shifted dual grating plasmonic structure

    E-Print Network [OSTI]

    Levy, Uriel

    Enhanced efficiency of thin film solar cells using a shifted dual grating plasmonic structure Ronen, "Light absorption enhancement in thin-film solar cells using whispering gallery modes in dielectric in thin film solar cells," Appl. Phys. Lett. 99(13), 131114 (2011). 10. H. R. Stuart and D. G. Hall

  12. Efficient, air-stable colloidal quantum dot solar cells encapsulated using atomic layer deposition of a nanolaminate barrier

    SciTech Connect (OSTI)

    Ip, Alexander H.; Labelle, André J.; Sargent, Edward H.

    2013-12-23

    Atomic layer deposition was used to encapsulate colloidal quantum dot solar cells. A nanolaminate layer consisting of alternating alumina and zirconia films provided a robust gas permeation barrier which prevented device performance degradation over a period of multiple weeks. Unencapsulated cells stored in ambient and nitrogen environments demonstrated significant performance losses over the same period. The encapsulated cell also exhibited stable performance under constant simulated solar illumination without filtration of harsh ultraviolet photons. This monolithically integrated thin film encapsulation method is promising for roll-to-roll processed high efficiency nanocrystal solar cells.

  13. Measure Guideline: High Efficiency Natural Gas Furnaces

    SciTech Connect (OSTI)

    Brand, L.; Rose, W.

    2012-10-01

    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.

  14. High efficiency switching-mode amplifiers for wireless communication systems

    E-Print Network [OSTI]

    Hung, Tsai-Pi

    2008-01-01

    M. Asbeck, “Design of high-efficiency current-mode class-Dand G. Rabjohn, “A high efficiency Chireix Out- phasingE-A new class of high efficiency tuned single-ended power

  15. High-performance ternary blend polymer solar cells involving both energy transfer and hole relay processes

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Lu, Luyao; Chen, Wei; Xu, Tao; Yu, Luping

    2015-06-04

    The integration of multiple materials with complementary absorptions into a single junction device is regarded as an efficient way to enhance the power conversion efficiency (PCE) of organic solar cells (OSCs). However, because of increased complexity with one more component, only limited high-performance ternary systems have been demonstrated previously. Here we report an efficient ternary blend OSC with a PCE of 9.2%. We show that the third component can reduce surface trap densities in the ternary blend. Detailed studies unravel that the improved performance results from synergistic effects of enlarged open circuit voltage, suppressed trap-assisted recombination, enhanced light absorption, increasedmore »hole extraction, efficient energy transfer and better morphology. The working mechanism and high device performance demonstrate new insights and design guidelines for high-performance ternary blend solar cells and suggest that ternary structure is a promising platform to boost the efficiency of OSCs.« less

  16. High efficiency novel window air conditioner

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Bansal, Pradeep

    2015-07-24

    This paper presents the technical development of a high efficiency window air conditioner. In order to achieve higher energy efficiency ratio (EER), the original capacity of the R410A unit was downgraded by replacing the original compressor with a lower capacity but higher EER compressor, while all heat exchangers and the chassis from the original unit were retained. The other subsequent major modifications included – the AC fan motor being replaced with a brushless high efficiency electronically commuted motor (ECM) motor, the capillary tube being replaced with a needle valve to better control the refrigerant flow and refrigerant set points, andmore »R410A being replaced with drop-in environmentally friendly binary mixture of R32 (85% molar concentration)/R125 (15% molar concentration). All these modifications resulted in significant EER enhancement of the modified unit.« less

  17. High efficiency novel window air conditioner

    SciTech Connect (OSTI)

    Bansal, Pradeep

    2015-07-24

    This paper presents the technical development of a high efficiency window air conditioner. In order to achieve higher energy efficiency ratio (EER), the original capacity of the R410A unit was downgraded by replacing the original compressor with a lower capacity but higher EER compressor, while all heat exchangers and the chassis from the original unit were retained. The other subsequent major modifications included – the AC fan motor being replaced with a brushless high efficiency electronically commuted motor (ECM) motor, the capillary tube being replaced with a needle valve to better control the refrigerant flow and refrigerant set points, and R410A being replaced with drop-in environmentally friendly binary mixture of R32 (85% molar concentration)/R125 (15% molar concentration). All these modifications resulted in significant EER enhancement of the modified unit.

  18. Oncor Energy Efficiency Programs Solar Photovoltaic and Demand Response 

    E-Print Network [OSTI]

    Tyra, K.; Hanel, J.

    2012-01-01

    Excitonic photovoltaic devices, including organic, hybrid organic/inorganic, and dye-sensitized solar cells, are attractive alternatives to conventional inorganic solar cells due to their potential for low cost and low ...

  19. Efficiency enhancement of luminescent solar concentrations for photovoltaic technologies

    E-Print Network [OSTI]

    Wang, Chunhua

    2011-01-01

    convert solar energy directly into electricity. A PV cell isSolar energy is a prominent renewable source of electricitysolar energy will become a very prominent renewable source of electricity.

  20. 14%-efficient flexible CdTe solar cells on ultra-thin glass substrates

    SciTech Connect (OSTI)

    Rance, W. L.; Burst, J. M.; Reese, M. O.; Gessert, T. A.; Metzger, W. K.; Barnes, T. M. [National Renewable Energy Laboratory, Golden, Colorado 80401 (United States); Meysing, D. M.; Wolden, C. A. [Colorado School of Mines, Golden, Colorado 80401 (United States); Garner, S.; Cimo, P. [Corning Incorporated, Corning, New York 14831 (United States)

    2014-04-07

    Flexible glass enables high-temperature, roll-to-roll processing of superstrate devices with higher photocurrents than flexible polymer foils because of its higher optical transmission. Using flexible glass in our high-temperature CdTe process, we achieved a certified record conversion efficiency of 14.05% for a flexible CdTe solar cell. Little has been reported on the flexibility of CdTe devices, so we investigated the effects of three different static bending conditions on device performance. We observed a consistent trend of increased short-circuit current and fill factor, whereas the open-circuit voltage consistently dropped. The quantum efficiency under the same static bend condition showed no change in the response. After storage in a flexed state for 24 h, there was very little change in device efficiency relative to its unflexed state. This indicates that flexible glass is a suitable replacement for rigid glass substrates, and that CdTe solar cells can tolerate bending without a decrease in device performance.

  1. Advanced Combustion Technology to Enable High Efficiency Clean...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Technology to Enable High Efficiency Clean Combustion Advanced Combustion Technology to Enable High Efficiency Clean Combustion Summary of advanced combustion research at Cummins...

  2. Tailored Materials for High Efficiency CIDI Engines (Caterpillar...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    High Efficiency CIDI Engines (Caterpillar CRADA) Tailored Materials for High Efficiency CIDI Engines (Caterpillar CRADA) 2009 DOE Hydrogen Program and Vehicle Technologies Program...

  3. Unregulated Emissions from High-Efficiency Clean Combustion Modes...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Unregulated Emissions from High-Efficiency Clean Combustion Modes - ORNL-FEERC Unregulated Emissions from High-Efficiency Clean Combustion Modes - ORNL-FEERC Poster presentation at...

  4. Novel Materials for High Efficiency Direct Methanol Fuel Cells...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Materials for High Efficiency Direct Methanol Fuel Cells Novel Materials for High Efficiency Direct Methanol Fuel Cells Presented at the Department of Energy Fuel Cell Projects...

  5. Highly Energy Efficient Directed Green Liquor Utilization (D...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Highly Energy Efficient Directed Green Liquor Utilization (D-GLU) Pulping Highly Energy Efficient Directed Green Liquor Utilization (D-GLU) Pulping This factsheet describes a...

  6. High Thermal Efficiency and Low Emissions with Supercritical...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    High Thermal Efficiency and Low Emissions with Supercritical Gasoline Injection-Ignition in a Light Duty Engine High Thermal Efficiency and Low Emissions with Supercritical...

  7. Energy Efficiency Opportunities in Federal High Performance Computing...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Energy Efficiency Opportunities in Federal High Performance Computing Data Centers Energy Efficiency Opportunities in Federal High Performance Computing Data Centers Case study...

  8. Enabling the Next Generation of High Efficiency Engines | Department...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    the Next Generation of High Efficiency Engines Enabling the Next Generation of High Efficiency Engines Discusses challenges and opportunities for next generation internal...

  9. Electrical and Thermal Transport Optimization of High Efficient...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Electrical and Thermal Transport Optimization of High Efficient n-type Skutterudites Electrical and Thermal Transport Optimization of High Efficient n-type Skutterudites Work on...

  10. Syngas Enhanced High Efficiency Low Temperature Combustion for...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Enhanced High Efficiency Low Temperature Combustion for Clean Diesel Engines Syngas Enhanced High Efficiency Low Temperature Combustion for Clean Diesel Engines A significant...

  11. Low Temperature Combustion Demonstrator for High Efficiency Clean...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Demonstrator for High Efficiency Clean Combustion Low Temperature Combustion Demonstrator for High Efficiency Clean Combustion Applied low temperature combustion to the Navistar...

  12. Low-Temperature Combustion Demonstrator for High-Efficiency Clean...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Low-Temperature Combustion Demonstrator for High-Efficiency Clean Combustion Low-Temperature Combustion Demonstrator for High-Efficiency Clean Combustion 2010 DOE Vehicle...

  13. Evaluation of High Efficiency Clean Combustion (HECC) Strategies...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    High Efficiency Clean Combustion (HECC) Strategies for Meeting Future Emissions Regulations in Light-Duty Engines Evaluation of High Efficiency Clean Combustion (HECC) Strategies...

  14. Combustion Targets for Low Emissions and High Efficiency | Department...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Targets for Low Emissions and High Efficiency Combustion Targets for Low Emissions and High Efficiency 2005 Diesel Engine Emissions Reduction (DEER) Conference Presentations and...

  15. Low Temperature Combustion Demonstrator for High Efficiency Clean...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Low Temperature Combustion Demonstrator for High Efficiency Clean Combustion Low Temperature Combustion Demonstrator for High Efficiency Clean Combustion 2009 DOE Hydrogen Program...

  16. High Efficiency Microturbine with Integral Heat Recovery - Presentatio...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    High Efficiency Microturbine with Integral Heat Recovery - Presentation by Capstone Turbine Corporation, June 2011 High Efficiency Microturbine with Integral Heat Recovery -...

  17. High Efficiency Microturbine with Integral Heat Recovery - Fact...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    High Efficiency Microturbine with Integral Heat Recovery - Fact Sheet, 2014 High Efficiency Microturbine with Integral Heat Recovery - Fact Sheet, 2014 Capstone Turbine...

  18. Greensburg Implements High-Efficiency Building Codes to Achieve...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Greensburg Implements High-Efficiency Building Codes to Achieve Long-Term Energy Savings Greensburg Implements High-Efficiency Building Codes to Achieve Long-Term Energy Savings...

  19. Progress toward Development of a High-Efficiency Zonal Thermoelectric...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    toward Development of a High-Efficiency Zonal Thermoelectric HVAC System for Automotive Applications Progress toward Development of a High-Efficiency Zonal Thermoelectric HVAC...

  20. Development of a High-Efficiency Zonal Thermoelectric HVAC System...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    a High-Efficiency Zonal Thermoelectric HVAC System for Automotive Applications Development of a High-Efficiency Zonal Thermoelectric HVAC System for Automotive Applications...

  1. Analyses Guided Optimization of Wide Range and High Efficiency...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Analyses Guided Optimization of Wide Range and High Efficiency Turbocharger Compressor Analyses Guided Optimization of Wide Range and High Efficiency Turbocharger Compressor...

  2. Heavy-Duty Engine Combustion Optimization for High Thermal Efficiency...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Combustion Optimization for High Thermal Efficiency Targeting EPA 2010 Emissions Heavy-Duty Engine Combustion Optimization for High Thermal Efficiency Targeting EPA 2010 Emissions...

  3. Glass-like thermal conductivity in high efficiency thermoelectric...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Glass-like thermal conductivity in high efficiency thermoelectric materials Glass-like thermal conductivity in high efficiency thermoelectric materials Discusses strategies to...

  4. Impact of High Solar Penetration in the Western Interconnection

    SciTech Connect (OSTI)

    Lew, D.; Miller, N.; Clark, K.; Jordan, G.; Gao, Z.

    2010-12-01

    This paper presents an overview of the variable characteristics of solar power, as well as the accompanying grid dynamic performance and operational economics for a system with significant solar generation. The paper will show results of economic operational simulations of a very high solar generation future for the western half of the United States.

  5. Efficiency enhancement of InGaN/GaN solar cells with nanostructures

    SciTech Connect (OSTI)

    Bai, J.; Yang, C. C.; Athanasiou, M.; Wang, T.

    2014-02-03

    We demonstrate InGaN/GaN multi-quantum-well solar cells with nanostructures operating at a wavelength of 520?nm. Nanostructures with a periodic nanorod or nanohole array are fabricated by means of modified nanosphere lithography. Under 1 sun air-mass 1.5 global spectrum illumination, a fill factor of 50 and an open circuit voltage of 1.9?V are achieved in spite of very high indium content in InGaN alloys usually causing degradation of crystal quality. Both the nanorod array and the nanohole array significantly improve the performance of solar cells, while a larger enhancement is observed for the nanohole array, where the conversion efficiency is enhanced by 51%.

  6. Efficient solar cooling: first ever non-tracking solar collectors powering a double effect absorption chiller

    E-Print Network [OSTI]

    Poiry, Heather Marie

    2011-01-01

    of a Solar Absorption Cooling and Heating System in CarnegieUsed for Grain Depot Cooling." Applied Thermal EngineeringKreith, Jan F. Kreider. "Solar Cooling." Principles of Solar

  7. Efficient solar cooling: first ever non-tracking solar collectors powering a double effect absorption chiller

    E-Print Network [OSTI]

    Poiry, Heather Marie

    2011-01-01

    an idea about how to design a solar thermal collector thatof great interest in the design of solar energy systems. TheRhodes. "Design and Performance of a Solar Powered Heating

  8. Efficient solar cooling: first ever non-tracking solar collectors powering a double effect absorption chiller

    E-Print Network [OSTI]

    Poiry, Heather Marie

    2011-01-01

    Ari Rabl, “Active Solar Collectors and Their Applications,”A. and Winston, R. (1980) “Solar collectors for low anda standard flat plate solar collector, and to the right is a

  9. Efficient solar cooling: first ever non-tracking solar collectors powering a double effect absorption chiller

    E-Print Network [OSTI]

    Poiry, Heather Marie

    2011-01-01

    natural gas and using solar thermal energy. There is a solarnatural gas or on solar thermal energy before it will switcha solar thermal system, strictly in terms of energy only.

  10. Limits in high efficiency quantum frequency conversion

    E-Print Network [OSTI]

    Nicolás Quesada; J. E. Sipe

    2015-08-13

    Frequency conversion is an enabling process in many quantum information protocols. In this letter we study fundamental limits to high efficiency frequency conversion imposed by time ordering corrections. Using the Magnus expansion, we argue that these corrections, which are usually considered detrimental, can be used to increase the efficiency of conversion under certain circumstances. The corrections induce a nonlinear behaviour in the probability of upconversion as a function of the pump intensity, significantly modifying the sinusoidal Rabi oscillations that are otherwise expected. Finally, by using a simple scaling argument, we explain why cascaded frequency conversion devices attenuate time ordering corrections, allowing the construction of near ideal quantum pulse gates.

  11. High voltage series connected tandem junction solar battery

    DOE Patents [OSTI]

    Hanak, Joseph J. (Lawrenceville, NJ)

    1982-01-01

    A high voltage series connected tandem junction solar battery which comprises a plurality of strips of tandem junction solar cells of hydrogenated amorphous silicon having one optical path and electrically interconnected by a tunnel junction. The layers of hydrogenated amorphous silicon, arranged in a tandem configuration, can have the same bandgap or differing bandgaps. The tandem junction strip solar cells are series connected to produce a solar battery of any desired voltage.

  12. Efficient solar cooling: first ever non-tracking solar collectors powering a double effect absorption chiller

    E-Print Network [OSTI]

    Poiry, Heather Marie

    2011-01-01

    to buffer the incoming solar power to the glycol loop so asarea the available power to the solar thermal collector was

  13. Polymer Separators for High Power, High Efficiency Microbial Fuel Cells

    E-Print Network [OSTI]

    1 Polymer Separators for High Power, High Efficiency Microbial Fuel Cells Guang Chen, Bin) was dissolved in 23 g H2O at 90 °C to prepare ~8 wt% transparent viscous polymer solution. To this solution in the water-swollen membranes. MFC reactor construction Anodes were composed of ammonia-treated carbon brushes

  14. Water Impacts of High Solar PV Electricity Penetration

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Water Impacts of High Solar PV Electricity Penetration Jordan Macknick and Stuart Cohen National Renewable Energy Laboratory (NREL) Technical Report NRELTP-6A20-63011 September...

  15. 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]

    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)

    1998-03-24

    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.

  16. Efficient methylammonium lead iodide perovskite solar cells with active layers from 300 to 900 nm

    SciTech Connect (OSTI)

    Momblona, C.; Malinkiewicz, O.; Soriano, A.; Gil-Escrig, L.; Bandiello, E.; Scheepers, M.; Bolink, H. J.; Edri, E.

    2014-08-01

    Efficient methylammonium lead iodide perovskite-based solar cells have been prepared in which the perovskite layer is sandwiched in between two organic charge transporting layers that block holes and electrons, respectively. This configuration leads to stable and reproducible devices that do not suffer from strong hysteresis effects and when optimized lead to efficiencies close to 15%. The perovskite layer is formed by using a dual-source thermal evaporation method, whereas the organic layers are processed from solution. The dual-source thermal evaporation method leads to smooth films and allows for high precision thickness variations. Devices were prepared with perovskite layer thicknesses ranging from 160 to 900 nm. The short-circuit current observed for these devices increased with increasing perovskite layer thickness. The main parameter that decreases with increasing perovskite layer thickness is the fill factor and as a result optimum device performance is obtained for perovskite layer thickness around 300 nm. However, here we demonstrate that with a slightly oxidized electron blocking layer the fill factor for the solar cells with a perovskite layer thickness of 900 nm increases to the same values as for the devices with thin perovskite layers. As a result the power conversion efficiencies for the cells with 300 and 900 nm are very similar, 12.7% and 12%, respectively.

  17. Towards the efficiency limits of silicon solar cells: how thin is too thin?

    E-Print Network [OSTI]

    Kowalczewski, Piotr

    2015-01-01

    It is currently possible to fabricate crystalline silicon solar cells with the absorber thickness ranging from a few hundreds of micrometers (conventional wafer-based cells) to devices as thin as $1\\,\\mu\\mathrm{m}$. In this work, we use a model single-junction solar cell to calculate the limits of energy conversion efficiency and estimate the optimal absorber thickness. The limiting efficiency for cells in the thickness range between 40 and $500\\,\\mu\\mathrm{m}$ is very similar and close to 29%. In this regard, we argue that decreasing the thickness below around $40\\,\\mu\\mathrm{m}$ is counter-productive, as it significantly reduces the maximum achievable efficiency, even when optimal light trapping is implemented. We analyse the roles of incomplete light trapping and extrinsic (bulk and surface) recombination mechanisms. For a reasonably high material quality, consistent with present-day fabrication techniques, the optimal thickness is always higher than a few tens of micrometers. We identify incomplete light ...

  18. High-efficiency carrier multiplication through direct photogeneration of

    E-Print Network [OSTI]

    Loss, Daniel

    of a variety of optoelectronic and photocatalytic devices, including solar cells, low-threshold lasers of multi-exciton populations in CdSe and PbSe nanocrystals and propose a model of how such populations multiplication (CM) for increasing the photocurrent of solar cells3­7 . CM is very efficient in quantum

  19. Efficiency enhancement of luminescent solar concentrations for photovoltaic technologies

    E-Print Network [OSTI]

    Wang, Chunhua

    2011-01-01

    and V.U. Ho?mann. Photovoltaic Solar Energy Gen- eration.Concentrations for Photovoltaic Technologies A dissertationThirteenth IEEE Photovoltaic Specialists Conference- 1978—

  20. Efficiency enhancement of luminescent solar concentrations for photovoltaic technologies

    E-Print Network [OSTI]

    Wang, Chunhua

    2011-01-01

    the manufacturing of solar cells and photovoltaic arrays hasfor providing us Photovoltaic cells, lumines- cent materialsthe currently available photovoltaic cells. The property of

  1. Geothermal, Energy Efficiency, and Solar PV Opportunities at Nissan USE 

    E-Print Network [OSTI]

    Ford, R.; Ong, J.; Reeder, J.; Sridar, V.; Zhang, R.

    2014-01-01

    is Driving Innovation ESL-IE-14-05-04 Proceedings of the Thrity-Sixth Industrial Energy Technology Conference New Orleans, LA. May 20-23, 2014 Research Areas Geothermal Solar Photovoltaics EE Verification ESL-IE-14-05-04 Proceedings of the Thrity... of the Thrity-Sixth Industrial Energy Technology Conference New Orleans, LA. May 20-23, 2014 Solar Costs Declining Solar Costs = Panels + O&M + Decom RMI Projected Commercial Solar Costs ESL-IE-14-05-04 Proceedings of the Thrity-Sixth Industrial Energy...

  2. Structure of All-Polymer Solar Cells Impedes Efficiency

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    thin films of semiconducting polymers as a possible alternative to silicon-based solar cells. Such devices would have the advantages of being cheap to produce,...

  3. Silicon Ink Technology Offers Path to Higher Efficiency Solar...

    Office of Environmental Management (EM)

    analysis. Partnering with National Labs Brings Cutting Edge Technology to Market Thin film solar panels produced by General Electric's PrimeStar in Arvada, Colorado | Image...

  4. Thermodynamics, Entropy, Information and the Efficiency of Solar Cells

    E-Print Network [OSTI]

    Abrams, Zeev R.

    2012-01-01

    and P.T. Landsberg, Thermodynamics and reciprocity of solar59. E. Yablonovitch, Thermodynamics of the fluorescentC. 139. E. Yablonovitch, Thermodynamics of the fluorescent

  5. Structure of All-Polymer Solar Cells Impedes Efficiency

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    device technology that will help realize the intrinsic potential of these materials. Solar Panels To Go Photovoltaic cells are a key component of most visions of a...

  6. Enhanced efficiency of graphene-silicon Schottky junction solar cells by doping with Au nanoparticles

    SciTech Connect (OSTI)

    Liu, X.; Zhang, X. W. Yin, Z. G.; Meng, J. H.; Gao, H. L.; Zhang, L. Q.; Zhao, Y. J.; Wang, H. L.

    2014-11-03

    We have reported a method to enhance the performance of graphene-Si (Gr/Si) Schottky junction solar cells by introducing Au nanoparticles (NPs) onto the monolayer graphene and few-layer graphene. The electron transfer between Au NPs and graphene leads to the increased work function and enhanced electrical conductivity of graphene, resulting in a remarkable improvement of device efficiency. By optimizing the initial thickness of Au layers, the power conversion efficiency of Gr/Si solar cells can be increased by more than three times, with a maximum value of 7.34%. These results show a route for fabricating efficient and stable Gr/Si solar cells.

  7. Maximizing Efficiency in Two-step Solar-thermochemical Fuel Production

    SciTech Connect (OSTI)

    Ermanoski, I.

    2015-05-01

    Widespread solar fuel production depends on its economic viability, largely driven by the solar-to-fuel conversion efficiency. Herein, the material and energy requirements in two-step solar-thermochemical cyclesare considered.The need for advanced redox active materials is demonstrated, by considering the oxide mass flow requirements at a large scale. Two approaches are also identified for maximizing the efficiency: optimizing reaction temperatures, and minimizing the pressure in the thermal reduction step by staged thermal reduction. The results show that each approach individually, and especially the two in conjunction, result in significant efficiency gains.

  8. New Fabrication Method Improves the Efficiency and Economics of Solar Cells (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2012-07-01

    Synthetic fabrication strategy optimizes the illumination geometry and transport properties of dye-sensitized solar cells. Using oriented titanium oxide (TiO{sub 2}) nanotube (NT) arrays has shown promise for dye-sensitized solar cells (DSSCs). High solar conversion efficiency requires that the incident light enters the cell from the photoelectrode side. However, for NT-based DSSCs, the light normally enters the cell through the counter electrode because a nontransparent titanium foil is typically used as the substrate for forming the aligned NTs and for making electrical contact with them. It has been synthetically challenging to prepare transparent TiO{sub 2} NT electrodes by directly anodizing Ti metal films on transparent conducting oxide (TCO) substrates because it is difficult to control the synthetic conditions. National Renewable Energy Laboratory (NREL) researchers have developed a general synthetic strategy for fabricating transparent TiO{sub 2} NT films on TCO substrates. With the aid of a conducting Nb-doped TiO{sub 2} (NTO) layer between the Ti film and TCO substrate, the Ti film can be anodized completely without degrading the TCO. The NTO layer protects the TCO from degradation through a self-terminating mechanism by arresting the electric field-assisted dissolution process at the NT-NTO interface. NREL researchers found that the illumination direction and wavelength of the light incident on the DSSCs strongly influenced the incident photon-to-current conversion efficiency, light-harvesting, and charge-collection properties, which, in turn, affect the photocurrent density, photovoltage, and solar energy conversion efficiency. Researchers also examined the effects of NT film thickness on the properties and performance of DSSCs and found that illuminating the cell from the photoelectrode side substantially increased the conversion efficiency compared with illuminating it from the counter-electrode side. This method solves a key challenge in fabricating NT-based DSSCs and determines an optimal illumination direction to use in these cells. The synthetic fabrication strategy will improve the economics and conversion efficiency of DSSCs.

  9. Optimization of a high efficiency FEL amplifier

    E-Print Network [OSTI]

    Schneidmiller, E A

    2014-01-01

    The problem of an efficiency increase of an FEL amplifier is now of great practical importance. Technique of undulator tapering in the post-saturation regime is used at the existing x-ray FELs LCLS and SACLA, and is planned for use at the European XFEL, Swiss FEL, and PAL XFEL. There are also discussions on the future of high peak and average power FELs for scientific and industrial applications. In this paper we perform detailed analysis of the tapering strategies for high power seeded FEL amplifiers. Application of similarity techniques allows us to derive universal law of the undulator tapering.

  10. 19th European Photovoltaic Solar Energy Conference Pre-Print 4AV.1.45 QUANTUM EFFICIENCY OF CdTe SOLAR CELLS IN FORWARD BIAS

    E-Print Network [OSTI]

    Sites, James R.

    19th European Photovoltaic Solar Energy Conference Pre-Print 4AV.1.45 QUANTUM EFFICIENCY OF CdTe SOLAR CELLS IN FORWARD BIAS M. Gloeckler and J. R. Sites Department of Physics, Colorado State@lamar.colostate.edu ABSTRACT: When the quantum efficiency of a CdS/CdTe solar cell is measured under forward voltage

  11. High-Temperature Solar Thermoelectric Generators (STEG)

    Broader source: Energy.gov [DOE]

    This presentation was delivered at the SunShot Concentrating Solar Power (CSP) Program Review 2013, held April 23–25, 2013 near Phoenix, Arizona.

  12. High Efficiency Colloidal Quantum Dot Phosphors

    SciTech Connect (OSTI)

    Kahen, Keith

    2013-12-31

    The project showed that non-Cd containing, InP-based nanocrystals (semiconductor materials with dimensions of ~6 nm) have high potential for enabling next-generation, nanocrystal-based, on chip phosphors for solid state lighting. Typical nanocrystals fall short of the requirements for on chip phosphors due to their loss of quantum efficiency under the operating conditions of LEDs, such as, high temperature (up to 150 °C) and high optical flux (up to 200 W/cm2). The InP-based nanocrystals invented during this project maintain high quantum efficiency (>80%) in polymer-based films under these operating conditions for emission wavelengths ranging from ~530 to 620 nm. These nanocrystals also show other desirable attributes, such as, lack of blinking (a common problem with nanocrystals which limits their performance) and no increase in the emission spectral width from room to 150 °C (emitters with narrower spectral widths enable higher efficiency LEDs). Prior to these nanocrystals, no nanocrystal system (regardless of nanocrystal type) showed this collection of properties; in fact, other nanocrystal systems are typically limited to showing only one desirable trait (such as high temperature stability) but being deficient in other properties (such as high flux stability). The project showed that one can reproducibly obtain these properties by generating a novel compositional structure inside of the nanomaterials; in addition, the project formulated an initial theoretical framework linking the compositional structure to the list of high performance optical properties. Over the course of the project, the synthetic methodology for producing the novel composition was evolved to enable the synthesis of these nanomaterials at a cost approximately equal to that required for forming typical conventional nanocrystals. Given the above results, the last major remaining step prior to scale up of the nanomaterials is to limit the oxidation of these materials during the tens of thousands of hours of LED operation. Once the LED phosphor lifetime specifications are met, these nanocrystals will enable white LEDs for solid state lighting to simultaneously have increased efficiency and improved light quality, in addition to enabling the creation of custom light spectrums. These improvements to white LEDs will help accelerate the adoption of SSL, leading to large savings in US and worldwide energy costs.

  13. Thermodynamics, Entropy, Information and the Efficiency of Solar Cells

    E-Print Network [OSTI]

    Abrams, Zeev R.

    2012-01-01

    CIGS, so the addition of the dc layer would not alter the material choice for a solar cell.solar cell, the use of GaAs has recently become feasible due to scalable manufacturing techniques, and compound materials such as CIGS (

  14. Efficiency enhancement of luminescent solar concentrations for photovoltaic technologies

    E-Print Network [OSTI]

    Wang, Chunhua

    2011-01-01

    improvement, the device performance is approaching the thermodynamic limit of similar to 28% for single- junction Si solar cells.improvement by PbS near infrared QDs due to the broaden absorption spectrum and near infrared emission properties for PV solar cells.

  15. Maintaining surface-phase purity is key to efficient open air fabricated cuprous oxide solar cells

    E-Print Network [OSTI]

    Hoye, Robert L. Z.; Brandt, Riley E.; Ievskaya, Yulia; Heffernan, Shane; Musselman, Kevin P.; Buonassisi, Tonio; MacManus-Driscoll, Judith L.

    2015-02-20

    Electrochemically deposited Cu 2O solar cells are receiving growing attention owing to a recent doubling in efficiency. This was enabled by the controlled chemical environment used in depositing doped ZnO layers by atomic layer deposition, which...

  16. Core-Shell Nanopillar Array Solar Cells using Cadmium Sulfide Coating on Indium Phosphide Nanopillars

    E-Print Network [OSTI]

    Tu, Bor-An Clayton

    2013-01-01

    A low-cost, high-efficiency solar cell based on dye-F. Dimroth, “High-efficiency solar cells from III-V compoundpower conversion efficiency of solar cells, quantification

  17. InGaAsP/InP intrastep quantum wells for enhanced solar energy conversion

    E-Print Network [OSTI]

    Chen, Winnie Victoria

    2012-01-01

    A low-cost, high-efficiency solar cell based on dye-well devices for high-efficiency tandem solar cells,” Solarbalance limit for solar cell efficiency (using a blackbody

  18. Semiconductor heterostructures and optimization of light-trapping structures for efficient thin-film solar cells

    E-Print Network [OSTI]

    Yu, Edward T.

    and optimization of light-trapping structures for efficient thin-film solar cells Claiborne O McPheeters1 , Dongzhi elements are integrated for light trapping. Measurements and simulations of GaAs solar cells with less than in their performance. Keywords: quantum-well, quantum-dot, scattering, diffraction, thin-film, GaAs, InAs, photovoltaic

  19. 15.7% Efficient 10-?m-Thick Crystalline Silicon Solar Cells Using Periodic Nanostructures

    E-Print Network [OSTI]

    Branham, Matthew Sanders

    Only ten micrometer thick crystalline silicon solar cells deliver a short-circuit current of 34.5 mA cm[superscript ?2] and power conversion efficiency of 15.7%. The record performance for a crystalline silicon solar cell ...

  20. Charge Trapping in High Efficiency Alternating Copolymers: Implication...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Charge Trapping in High Efficiency Alternating Copolymers: Implications in Organic Photovoltaic Device Efficiency Home > Research > ANSER Research Highlights > Charge Trapping in...

  1. High Engine Efficiency at 2010 Emissions | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Engine Efficiency at 2010 Emissions High Engine Efficiency at 2010 Emissions 2005 Diesel Engine Emissions Reduction (DEER) Conference Presentations and Posters 2005deernelson.pdf...

  2. High-Efficiency Window Air Conditioners - Building America Top...

    Energy Savers [EERE]

    Efficiency Window Air Conditioners - Building America Top Innovation High-Efficiency Window Air Conditioners - Building America Top Innovation This photo shows a window air...

  3. High Efficiency Microturbine with Integral Heat Recovery - Fact...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Efficiency Microturbine with Integral Heat Recovery - Fact Sheet, 2014 High Efficiency Microturbine with Integral Heat Recovery - Fact Sheet, 2014 Capstone Turbine Corporation, in...

  4. Advanced High Efficiency Clean Diesel Combustion with Low Cost...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Efficiency Clean Diesel Combustion with Low Cost for Hybrid Engines Advanced High Efficiency Clean Diesel Combustion with Low Cost for Hybrid Engines Clean, in-cylinder combustion...

  5. High Efficiency Full Expansion (FEx) Engine for Automotive Application...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Full Expansion (FEx) Engine for Automotive Applications High Efficiency Full Expansion (FEx) Engine for Automotive Applications Large increases in engine thermal efficiency result...

  6. Electron Transfer Dynamics in Efficient Molecular Solar Cells

    SciTech Connect (OSTI)

    Meyer, Gerald John

    2014-10-01

    This research provided new mechanistic insights into surface mediated photochemical processes relevant to solar energy conversion. In this past three years our research has focused on oxidation photo-redox chemistry and on the role surface electric fields play on basic spectroscopic properties of molecular-semiconductor interfaces. Although this research as purely fundamental science, the results and their interpretation have relevance to applications in dye sensitized and photogalvanic solar cells as well as in the storage of solar energy in the form of chemical bonds.

  7. Solar and Energy Efficiency Justice | Department of Energy

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX E LIST OF APPLICABLE DIRECTIVES PursuantEnergySolar FlareSolarSolar and Energy

  8. PROJECT PROFILE: High-Efficiency, Low-Cost, One-Sun, III-V Photovoltaics

    Broader source: Energy.gov [DOE]

    Low-cost III-V photovoltaics have the potential to lower the levelized cost of energy (LCOE) because III-V cells outperform silicon in terms of efficiency and annual energy harvesting efficiency. In this project, researchers will address both the high costs of III-V epitaxy and single crystal substrates. Hydride vapor phase epitaxy (HVPE) is the most promising inexpensive, rapid-growth technique for high efficiency, III-V materials. The continued development of high-throughput HVPE, will be coupled with novel epitaxial liftoff strategies to enable III-V solar cells that are cost-competitive under one-sun conditions.

  9. High Quantum Efficiency OLED Lighting Systems

    SciTech Connect (OSTI)

    Shiang, Joseph [General Electric (GE) Global Research, Fairfield, CT (United States)

    2011-09-30

    The overall goal of the program was to apply improvements in light outcoupling technology to a practical large area plastic luminaire, and thus enable the product vision of an extremely thin form factor high efficiency large area light source. The target substrate was plastic and the baseline device was operating at 35 LPW at the start of the program. The target LPW of the program was a >2x improvement in the LPW efficacy and the overall amount of light to be delivered was relatively high 900 lumens. Despite the extremely difficult challenges associated with scaling up a wet solution process on plastic substrates, the program was able to make substantial progress. A small molecule wet solution process was successfully implemented on plastic substrates with almost no loss in efficiency in transitioning from the laboratory scale glass to large area plastic substrates. By transitioning to a small molecule based process, the LPW entitlement increased from 35 LPW to 60 LPW. A further 10% improvement in outcoupling efficiency was demonstrated via the use of a highly reflecting cathode, which reduced absorptive loss in the OLED device. The calculated potential improvement in some cases is even larger, ~30%, and thus there is considerable room for optimism in improving the net light coupling efficacy, provided absorptive loss mechanisms are eliminated. Further improvements are possible if scattering schemes such as the silver nanowire based hard coat structure are fully developed. The wet coating processes were successfully scaled to large area plastic substrate and resulted in the construction of a 900 lumens luminaire device.

  10. High Efficiency Cold Climate Heat Pump

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:FinancingPetroleum12,ExecutiveFinancing ProgramsDepartment of¡ ¢HelpHigh Efficiency Cold Climate

  11. Structure of All-Polymer Solar Cells Impedes Efficiency

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    that will help realize the intrinsic potential of these materials. Solar Panels To Go Photovoltaic cells are a key component of most visions of a clean-energy future. However,...

  12. Efficient light-trapping nanostructures in thin silicon solar cells

    E-Print Network [OSTI]

    Han, Sang Eon

    We examine light-trapping in thin crystalline silicon periodic nanostructures for solar cell applications. Using group theory, we show that light-trapping can be improved over a broad band when structural mirror symmetry ...

  13. Efficient light trapping structure in thin film silicon solar cells

    E-Print Network [OSTI]

    Sheng, Xing

    Thin film silicon solar cells are believed to be promising candidates for continuing cost reduction in photovoltaic panels because silicon usage could be greatly reduced. Since silicon is an indirect bandgap semiconductor, ...

  14. California: TetraCell Silicon Solar Cell Improves Efficiency...

    Broader source: Energy.gov (indexed) [DOE]

    used in traditional screen printed solar cells-with copper, which is much lower in cost and subject to less market-based price volatility. This technology also allows for...

  15. Structure of All-Polymer Solar Cells Impedes Efficiency

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    are not sharp enough. This insight will lead to new approaches to all-polymer device technology that will help realize the intrinsic potential of these materials. Solar Panels To...

  16. Structure of All-Polymer Solar Cells Impedes Efficiency

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    in model all-polymer solar cells is caused by domains that are too large and interfaces that are not sharp enough. This insight will lead to new approaches to all-polymer...

  17. High Efficiency, Illumination Quality OLEDs for Lighting

    SciTech Connect (OSTI)

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

    2008-03-31

    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

  18. High Efficient Clean Combustion for SuperTruck | Department of...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Efficient Clean Combustion for SuperTruck High Efficient Clean Combustion for SuperTruck Presentation given at the 16th Directions in Engine-Efficiency and Emissions Research...

  19. High Efficiency Microturbine with Integral Heat Recovery

    SciTech Connect (OSTI)

    2010-10-01

    Fact sheet: this project will develop a clean, cost-effective 370 kW microturbine with 42% net electrical efficiency and 85% total CHP efficiency.

  20. Affordable Solar Energy Solar Powder is a solar-energy company that has developed an innovative technology that will set a new

    E-Print Network [OSTI]

    Jawitz, James W.

    and distribute high-efficiency, high yield, low cost solar panels. The company is making green energy more and selenium. CIGS was chosen because of its high cell efficiency, high energy yield, and now with Solar Powder-powder that is mixed with a secret Solar Powder solvent to allow for liquid application. Solar Powder solar panels can

  1. NANOCOMPOSITE ENABLED SENSITIZED SOLAR CELL

    E-Print Network [OSTI]

    Phuyal, Dibya

    2012-01-01

    potential as a low-cost solar energy conversion technology.Grätzel. A Low-Cost, High-Efficiency Solar Cell Based on Dye1) reducing the cost of solar cells by depositing

  2. Improving the Power Conversion Efficiency of Ultrathin Organic Solar Cells by Incorporating Plasmonic Effects of Spheroidal Metallic Nanoparticles

    E-Print Network [OSTI]

    Park, Namkyoo

    Improving the Power Conversion Efficiency of Ultrathin Organic Solar Cells by Incorporating be exploited to achieve efficient harvesting of solar energy. Notably, the incorporation of plasmonic effects can allow the light harvesting capability of a solar cell to be maintained even as the thickness

  3. Solution-Processed Organic Solar Cells with Power Conversion Efficiencies of 2.5% using Benzothiadiazole/Imide-Based Acceptors

    E-Print Network [OSTI]

    McGehee, Michael

    Solution-Processed Organic Solar Cells with Power Conversion Efficiencies of 2.5% using achieved 0.1% power-conversion efficiency. KEYWORDS: organic electronics, solar cells, photovoltaic devices significantly different behav- iors in bulk heterojunction (BHJ) solar cells using poly(3-hexylthiophene) (P3HT

  4. Microscale solar cells for high concentration on polycrystalline Cu(In,Ga)Se2 Myriam Paire,1,2,3,4,a)

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    thin film solar cell material,7 and efficiencies over 20% were achieved recently. We study CIGS to decrease with illumination. The device described in this letter is a glass/Mo/CIGS/ CdS/ZnO solar cellMicroscale solar cells for high concentration on polycrystalline Cu(In,Ga)Se2 thin films Myriam

  5. New Metallization Technique Suitable for 6-MW Pilot Production of Efficient Multicrystalline Solar Cells Using Upgraded Metallurgical Silicon: Final Technical Progress Report, December 17, 2007-- June 16, 2009

    Broader source: Energy.gov [DOE]

    This report describes CaliSolar's work as a Photovoltaic Technology Incubator awardee within the U.S. Department of Energy's Solar Energy Technologies Program. The term of this subcontract with the National Renewable Energy Laboratory was two years. During this time, CaliSolar evolved from a handful of employees to over 100 scientists, engineers, technicians, and operators. On the technical side, the company transitioned from a proof-of-concept through pilot-scale to large-scale industrial production. A fully automated 60-megawatt manufacturing line was commissioned in Sunnyvale, California. The facility converts upgraded metallurgical-grade silicon feedstock to ingots, wafers, and high-efficiency multicrystalline solar cells.

  6. New Metallization Technique Suitable for 6-MW Pilot Production of Efficient Multicrystalline Solar Cells Using Upgraded Metallurgical Silicon: Final Technical Progress Report, December 17, 2007 -- June 16, 2009

    SciTech Connect (OSTI)

    Ounadjela, K.; Blosse, A.

    2010-08-01

    This report describes CaliSolar's work as a Photovoltaic Technology Incubator awardee within the U.S. Department of Energy's Solar Energy Technologies Program. The term of this subcontract with the National Renewable Energy Laboratory was two years. During this time, CaliSolar evolved from a handful of employees to over 100 scientists, engineers, technicians, and operators. On the technical side, the company transitioned from a proof-of-concept through pilot-scale to large-scale industrial production. A fully automated 60-megawatt manufacturing line was commissioned in Sunnyvale, California. The facility converts upgraded metallurgical-grade silicon feedstock to ingots, wafers, and high-efficiency multicrystalline solar cells.

  7. Analysis of the efficiency of intermediate band solar cells based on quantum dot supercrystals

    SciTech Connect (OSTI)

    Heshmati, S; Golmohammadi, S; Abedi, K; Taleb, H

    2014-03-28

    We have studied the influence of the quantum-dot (QD) width and the quantum-dot conduction band (QD-CB) offset on the efficiency of quantum-dot intermediate band solar cells (QD-IBSCs). Simulation results demonstrate that with increasing QD-CB offset and decreasing QD width, the maximum efficiency is achieved. (laser applications and other topics in quantum electronics)

  8. Structure of All-Polymer Solar Cells Impedes Efficiency

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    cells. Such devices would have the advantages of being cheap to produce, lightweight, and flexible. The catch? Their efficiency in converting light into electricity is still...

  9. Development of a New Generation, High Efficiency PEM Fuel Cell...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    a New Generation, High Efficiency PEM Fuel Cell Based, CHP System Development of a New Generation, High Efficiency PEM Fuel Cell Based, CHP System Part of a 100 million fuel cell...

  10. Development of High-Efficiency Clean Combustion Engines Designs...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    High-Efficiency Clean Combustion Engines Designs for SI and CI Engines Development of High-Efficiency Clean Combustion Engines Designs for SI and CI Engines 2010 DOE Vehicle...

  11. High throughput solar cell ablation system

    DOE Patents [OSTI]

    Harley, Gabriel; Pass, Thomas; Cousins, Peter John; Viatella, John

    2014-10-14

    A solar cell is formed using a solar cell ablation system. The ablation system includes a single laser source and several laser scanners. The laser scanners include a master laser scanner, with the rest of the laser scanners being slaved to the master laser scanner. A laser beam from the laser source is split into several laser beams, with the laser beams being scanned onto corresponding wafers using the laser scanners in accordance with one or more patterns. The laser beams may be scanned on the wafers using the same or different power levels of the laser source.

  12. High throughput solar cell ablation system

    DOE Patents [OSTI]

    Harley, Gabriel; Pass, Thomas; Cousins, Peter John; Viatella, John

    2012-09-11

    A solar cell is formed using a solar cell ablation system. The ablation system includes a single laser source and several laser scanners. The laser scanners include a master laser scanner, with the rest of the laser scanners being slaved to the master laser scanner. A laser beam from the laser source is split into several laser beams, with the laser beams being scanned onto corresponding wafers using the laser scanners in accordance with one or more patterns. The laser beams may be scanned on the wafers using the same or different power levels of the laser source.

  13. High efficiency Brayton cycles using LNG

    DOE Patents [OSTI]

    Morrow, Charles W. (Albuquerque, NM)

    2006-04-18

    A modified, closed-loop Brayton cycle power conversion system that uses liquefied natural gas as the cold heat sink media. When combined with a helium gas cooled nuclear reactor, achievable efficiency can approach 68 76% (as compared to 35% for conventional steam cycle power cooled by air or water). A superheater heat exchanger can be used to exchange heat from a side-stream of hot helium gas split-off from the primary helium coolant loop to post-heat vaporized natural gas exiting from low and high-pressure coolers. The superheater raises the exit temperature of the natural gas to close to room temperature, which makes the gas more attractive to sell on the open market. An additional benefit is significantly reduced costs of a LNG revaporization plant, since the nuclear reactor provides the heat for vaporization instead of burning a portion of the LNG to provide the heat.

  14. High Efficiency Organic Light Emitting Devices for Lighting

    SciTech Connect (OSTI)

    So, Franky; Tansu, Nelson; Gilchrist, James

    2013-06-30

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

  15. Simulation of High Efficiency Clean Combustion Engines and Detailed...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    ongoing work exploring fuel chemistry, analysis of and improving simulation methodologies for high efficiency clean combustion regimes, and computational performance...

  16. High temperature solar thermal technology: The North Africa Market

    SciTech Connect (OSTI)

    Not Available

    1990-12-01

    High temperature solar thermal (HTST) technology offers an attractive option for both industrialized and non-industrialized countries to generate electricity and industrial process steam. The purpose of this report is to assess the potential market for solar thermal applications in the North African countries of Algeria, Egypt, Morocco and Tunisia. North Africa was selected because of its outstanding solar resource base and the variety of applications to be found there. Diminishing oil and gas resources, coupled with expanding energy needs, opens a large potential market for the US industry. The US high temperature solar trough industry has little competition globally and could build a large market in these areas. The US is already familiar with certain solar markets in North Africa due to the supplying of substantial quantities of US-manufactured flat plate collectors to this region.

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

    E-Print Network [OSTI]

    Viswanathan, R.

    2011-01-01

    of Various Coatings, Substrate Materials and Solar Collectorl'Optimiz ctive Coatings for Solar Collectors", N77-11529,on High Efficiency Solar Collector Coatings", N77 -30286,

  18. Tucson, Arizona: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE)

    Broader source: Energy.gov [DOE]

    This brochure provides an overview of the challenges and successes of Tucson, AZ, a 2007 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  19. Knoxville, Tennessee: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE)

    Broader source: Energy.gov [DOE]

    This brochure provides an overview of the challenges and successes of Knoxville, TN, a 2008 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  20. Milwaukee, Wisconsin: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE)

    Broader source: Energy.gov [DOE]

    This brochure provides an overview of the challenges and successes of Milwaukee, WI, a 2008 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  1. Pittsburgh, Pennsylvania: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE)

    Broader source: Energy.gov [DOE]

    This brochure provides an overview of the challenges and successes of Pittsburgh, PA, a 2007 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  2. Houston, Texas: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE)

    Broader source: Energy.gov [DOE]

    This brochure provides an overview of the challenges and successes of Houston, TX, a 2008 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  3. Austin, Texas: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE)

    Broader source: Energy.gov [DOE]

    This brochure provides an overview of the challenges and successes of Austin, Texas, a 2007 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  4. Sacramento, California: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE)

    Broader source: Energy.gov [DOE]

    This brochure provides an overview of the challenges and successes of Sacramento, CA, a 2008 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  5. Ann Arbor, Michigan: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE)

    Office of Energy Efficiency and Renewable Energy (EERE)

    This brochure provides an overview of the challenges and successes of Ann Arbor, Michigan, a 2007 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  6. Salt Lake City, Utah: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE)

    Office of Energy Efficiency and Renewable Energy (EERE)

    This brochure provides an overview of the challenges and successes of Salt Lake City, UT, a 2007 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  7. Berkeley, California: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE)

    Office of Energy Efficiency and Renewable Energy (EERE)

    This brochure provides an overview of the challenges and successes of Berkeley, CA, a 2007 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  8. Boston Massachusetts: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE)

    Office of Energy Efficiency and Renewable Energy (EERE)

    This brochure provides an overview of the challenges and successes of Boston, MA, a 2007 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  9. Orlando, Florida: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE)

    Office of Energy Efficiency and Renewable Energy (EERE)

    This brochure provides an overview of the challenges and successes of Orlando, FL, a 2008 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  10. Madison, Wisconsin: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE)

    Broader source: Energy.gov [DOE]

    This brochure provides an overview of the challenges and successes of Madison, WI, a 2007 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  11. Santa Rosa, California: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE)

    Office of Energy Efficiency and Renewable Energy (EERE)

    This brochure provides an overview of the challenges and successes of Santa Rosa, CA, a 2008 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  12. Denver, Colorado: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE)

    Office of Energy Efficiency and Renewable Energy (EERE)

    This brochure provides an overview of the challenges and successes of Denver, Colorado, a 2008 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  13. New Orleans, Louisiana: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE)

    Broader source: Energy.gov [DOE]

    This brochure provides an overview of the challenges and successes of New Orleans, LA, a 2007 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  14. Seattle, Washington: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE)

    Broader source: Energy.gov [DOE]

    This brochure provides an overview of the challenges and successes of Seattle, WA, a 2008 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  15. San Diego, California: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE)

    Broader source: Energy.gov [DOE]

    This brochure provides an overview of the challenges and successes of San Diego, CA, a 2007 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  16. Philadelphia, Pennsylvania: Solar in Action (Brochure), Solar America Cities, Energy Efficiency & Renewable Energy (EERE)

    Office of Energy Efficiency and Renewable Energy (EERE)

    This brochure provides an overview of the challenges and successes of Philadelphia, PA, a 2008 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

  17. PV Solar Site Assessment (Milwaukee High School)

    Broader source: Energy.gov [DOE]

    The purpose of this assessment is to provide site-specific information on how a solar electric (also referred to as a photovoltaic, or PV) system would perform at your location, including information on estimated physical size, rated output, energy production, costs, financial incentives and mounting options. Site assessors are required to present unbiased information and may not recommend contractors or products.

  18. HIGH-EFFICIENCY POWER AMPLIFIERS FOR LINEAR TRANSMITTERS

    E-Print Network [OSTI]

    Popovic, Zoya

    HIGH-EFFICIENCY POWER AMPLIFIERS FOR LINEAR TRANSMITTERS by N´ESTOR DAVID L´OPEZ B.S., University;This thesis entitled: High-Efficiency Power Amplifiers for Linear Transmitters written by N´estor David in the above mentioned discipline #12;L´opez, N´estor David (Ph.D., Electrical Engineering) High-Efficiency

  19. High-Performance Home Technologies: Solar Thermal & Photovoltaic Systems

    SciTech Connect (OSTI)

    Baechler, M.; Gilbride, T.; Ruiz, K.; Steward, H.; Love, P.

    2007-06-01

    This document is the sixth volume of the Building America Best Practices Series. It presents information that is useful throughout the United States for enhancing the energy efficiency practices in the specific climate zones that are presented in the first five Best Practices volumes. It provides an introduction to current photovoltaic and solar thermal building practices. Information about window selection and shading is included.

  20. Ultrahigh Efficiency Multiband Solar Cells Final Report forDirector's Innovation Initiative Project DII-2005-1221

    SciTech Connect (OSTI)

    Ager III, Joel W.; Walukiewicz, W.; Yu, Kin Man

    2006-03-29

    The unique properties of the semiconductor ZnTeO were explored and developed to make multiband solar cells. Like a multijunction cell, multiband solar cells use different energy gaps to convert the majority of the solar spectrum to electrical current while minimizing losses due to heating. Unlike a multijunction cell, this is accomplished within a single material in a multiband cell. ZnTe{sub 1-x}O{sub x} films with x up to 2% were synthesized and shown to have the requisite unique band structure (2 conduction bands) for multiband function. Prototype solar cells based on an n-type ZnTe{sub 1-x}O{sub x} multiband top layer and a p-type ZnTe substrate were fabricated. Contacts to the cell and the series resistance of the substrate were identified as challenges for good electrical performance. Both photovoltage and small photocurrents were demonstrated under AMO illumination. A second semiconductor system, GaN{sub x}As{sub 1-y-x}P{sub y}, was shown to have multiband function. This alloy system may have the greatest potential to realize the promise of high efficiency multiband solar cells because of the relatively advanced technology base that exists for the manufacturing of III-V-alloy-based IC and opto-electronic devices (including multijunction solar cells).