National Library of Energy BETA

Sample records for multijunction solar cells

  1. Multi-junction solar cell device

    DOE Patents [OSTI]

    Friedman, Daniel J.; Geisz, John F.

    2007-12-18

    A multi-junction solar cell device (10) is provided. The multi-junction solar cell device (10) comprises either two or three active solar cells connected in series in a monolithic structure. The multi-junction device (10) comprises a bottom active cell (20) having a single-crystal silicon substrate base and an emitter layer (23). The multi-junction device (10) further comprises one or two subsequent active cells each having a base layer (32) and an emitter layer (23) with interconnecting tunnel junctions between each active cell. At least one layer that forms each of the top and middle active cells is composed of a single-crystal III-V semiconductor alloy that is substantially lattice-matched to the silicon substrate (22). The polarity of the active p-n junction cells is either p-on-n or n-on-p. The present invention further includes a method for substantially lattice matching single-crystal III-V semiconductor layers with the silicon substrate (22) by including boron and/or nitrogen in the chemical structure of these layers.

  2. Voltage-matched configurations for multijunction solar cells

    SciTech Connect (OSTI)

    Gee, J.M.

    1987-01-01

    Novel methods for interconnecting the subcells of a multijunction solar cell are investigated. The subcells are connected in parallel in these new methods. The bandgaps of the subcells must be selected for matched voltages when operated in parallel. We refer to multijunction solar cells with the subcells connected in parallel as having a voltage-matched configuration. Computer analyses of multijunction solar cells with a voltage-matched configuration and with series-connected subcells were performed. Roughly, the same performance with either approach for a multijunction cell with optimized bandgaps was found. Several advantages for the voltage-matched configuration relative to multijunction solar cells with series-connected subcells were identified, including wider selection of bandgaps for optimal performance, less sensitivity to radiation damage, and less sensitivity to spectral variations.

  3. Modeling of the electronic transport in multijunction solar cells

    SciTech Connect (OSTI)

    Rau, U.; Goldbach, M.

    1994-12-31

    Simulations of the electrical transport in multijunction thin-film solar cells made from polycrystalline silicon are presented. The authors investigate the effect of the grain size on the efficiency of the multijunction solar cell. Here, they concentrate on micro crystalline material with a high recombination velocity at the grain boundaries of 10{sup 4}cm/s. Typical results of their calculations demonstrate that based on the multijunction design structure consisting of 8 or more layers efficiencies of 14% may be obtained from 12--20 {micro}m thick solar cells.

  4. Heterojunction for Multi-Junction Solar Cells - Energy Innovation Portal

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

    Photovoltaic Solar Photovoltaic Advanced Materials Advanced Materials Find More Like This Return to Search Heterojunction for Multi-Junction Solar Cells Sandia National Laboratories Contact SNL About This Technology Publications: PDF Document Publication Market Sheet (1,250 KB) Technology Marketing SummarySandia National Laboratories has created a semiconductor p-n heterojunction for use in forming a photodetector that has applications for use in a multi-junction solar cell and detecting light

  5. Superstrate sub-cell voltage-matched multijunction solar cells

    DOE Patents [OSTI]

    Mascarenhas, Angelo; Alberi, Kirstin

    2016-03-15

    Voltage-matched thin film multijunction solar cell and methods of producing cells having upper CdTe pn junction layers formed on a transparent substrate which in the completed device is operatively positioned in a superstate configuration. The solar cell also includes a lower pn junction formed independently of the CdTe pn junction and an insulating layer between CdTe and lower pn junctions. The voltage-matched thin film multijunction solar cells further include a parallel connection between the CdTe pn junction and lower pn junctions to form a two-terminal photonic device. Methods of fabricating devices from independently produced upper CdTe junction layers and lower junction layers are also disclosed.

  6. Voltage-matched multijunction solar cell architectures for integrating PV

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

    technologies - Energy Innovation Portal Find More Like This Return to Search Voltage-matched multijunction solar cell architectures for integrating PV technologies National Renewable Energy Laboratory Contact NREL About This Technology Technology Marketing Summary The U.S. Department of Energy SunShot Initiative aims to reduce the total installed cost of solar energy systems to $.06 per kilowatt-hour (kWh) by the year 2020. Reducing the cost of solar electricity requires that solar cell

  7. Enhanced Photon Recycling in Multijunction Solar Cells

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

    Ferreira, X. Li, E. Yablonovitch, a nd J .A. R ogers, " Device A rchitectures f or E nhanced Photon Recycling in Thin---Film MulQjuncQon Solar Cells." Adv. Energy M ater. (2014). ...

  8. New Multijunction Design Leads to Ultra-Efficient Solar Cell...

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

    as inverted metamorphic multijunctions-a design concept invented at NREL-can achieve ... The figure at right illustrates the materials and design of the NREL cell. First, ...

  9. Antireflection Coating Design for Series Interconnected Multi-Junction Solar Cells

    SciTech Connect (OSTI)

    AIKEN,DANIEL J.

    1999-11-29

    AR coating design for multi-junction solar cells can be more challenging than in the single junction case. Reasons for this are discussed. Analytical expressions used to optimize AR coatings for single junction solar cells are extended for use in monolithic, series interconnected multi-junction solar cell AR coating design. The result is an analytical expression which relates the solar cell performance (through J{sub SC}) directly to the AR coating design through the device reflectance. It is also illustrated how AR coating design can be used to provide an additional degree of freedom for current matching multi-junction devices.

  10. Generalized Optoelectronic Model of Series-Connected Multijunction Solar Cells

    SciTech Connect (OSTI)

    Geisz, John F.; Steiner, Myles A.; Garcia, Ivan; France, Ryan M.; McMahon, William E.; Osterwald, Carl R.; Friedman, Daniel J.

    2015-10-02

    The emission of light from each junction in a series-connected multijunction solar cell, we found, both complicates and elucidates the understanding of its performance under arbitrary conditions. Bringing together many recent advances in this understanding, we present a general 1-D model to describe luminescent coupling that arises from both voltage-driven electroluminescence and voltage-independent photoluminescence in nonideal junctions that include effects such as Sah-Noyce-Shockley (SNS) recombination with n ≠ 2, Auger recombination, shunt resistance, reverse-bias breakdown, series resistance, and significant dark area losses. The individual junction voltages and currents are experimentally determined from measured optical and electrical inputs and outputs of the device within the context of the model to fit parameters that describe the devices performance under arbitrary input conditions. Furthermore, our techniques to experimentally fit the model are demonstrated for a four-junction inverted metamorphic solar cell, and the predictions of the model are compared with concentrator flash measurements.

  11. Generalized Optoelectronic Model of Series-Connected Multijunction Solar Cells

    SciTech Connect (OSTI)

    Geisz, John F.; Steiner, Myles A.; Garcia, Ivan; France, Ryan M.; McMahon, William E.; Osterwald, Carl R.; Friedman, Daniel J.

    2015-11-01

    The emission of light from each junction in a series-connected multijunction solar cell, we found, both complicates and elucidates the understanding of its performance under arbitrary conditions. Bringing together many recent advances in this understanding, we present a general 1-D model to describe luminescent coupling that arises from both voltage-driven electroluminescence and voltage-independent photoluminescence in nonideal junctions that include effects such as Sah-Noyce-Shockley (SNS) recombination with n ≠ 2, Auger recombination, shunt resistance, reverse-bias breakdown, series resistance, and significant dark area losses. The individual junction voltages and currents are experimentally determined from measured optical and electrical inputs and outputs of the device within the context of the model to fit parameters that describe the devices performance under arbitrary input conditions. Furthermore, our techniques to experimentally fit the model are demonstrated for a four-junction inverted metamorphic solar cell, and the predictions of the model are compared with concentrator flash measurements.

  12. Polycrystalline Thin-Film Multijunction Solar Cells

    SciTech Connect (OSTI)

    Noufi, R.; Wu, X.; Abu-Shama, J.; Ramanathan, K; Dhere, R.; Zhou, J.; Coutts, T.; Contreras, M.; Gessert, T.; Ward, J. S.

    2005-11-01

    We present a digest of our research on the thin-film material components that comprise the top and bottom cells of three different material systems and the tandem devices constructed from them.

  13. Cross-Sectional Transport Imaging in a Multijunction Solar Cell

    SciTech Connect (OSTI)

    Haegel, Nancy M.; Ke, Chi-Wen; Taha, Hesham; Guthrey, Harvey; Fetzer, C. M.; King, Richard

    2015-06-14

    Combining highly localized electron-beam excitation at a point with the spatial resolution capability of optical near-field imaging, we have imaged carrier transport in a cross-sectioned multijunction (GaInP/GaInAs/Ge) solar cell. We image energy transport associated with carrier diffusion throughout the full width of the middle (GaInAs) cell and luminescent coupling from point excitation in the top cell GaInP to the middle cell. Supporting cathodoluminescence and near-field photoluminescence measurements demonstrate excitation-dependent Fermi level splitting effects that influence cross-sectioned spectroscopy results as well as transport limitations on the spatial resolution of cross-sectional measurements.

  14. NREL Spurred the Success of Multijunction Solar Cells (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2013-08-01

    Many scientists once believed that high-quality gallium indium phosphide (GaInP) alloys could not be grown for use as semiconductors because the alloys would separate. However, researchers at the National Renewable Energy Laboratory (NREL) thought differently, and they employed GaInP in a material combination that allowed the multijunction cell to flourish. The multijunction cell is now the workhorse that powers satellites and the catalyst for renewed interest in concentrator photovoltaic products.

  15. Analysis of a four lamp flash system for calibrating multi-junction solar cells under concentrated light

    SciTech Connect (OSTI)

    Schachtner, Michael Prado, Marcelo Loyo; Reichmuth, S. Kasimir; Siefer, Gerald; Bett, Andreas W.

    2015-09-28

    It has been known for a long time that the precise characterization of multi-junction solar cells demands spectrally tunable solar simulators. The calibration of innovative multi-junction solar cells for CPV applications now requires tunable solar simulators which provide high irradiation levels. This paper describes the commissioning and calibration of a flash-based four-lamp simulator to be used for the measurement of multi-junction solar cells with up to four subcells under concentrated light.

  16. Materials en Multi-junction Solar Cells to Push CPV Efficiencies...

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

    ceem.ucsb.edurss News and Events - Center for Energy Efficient Materials en Multi-junction Solar Cells to Push CPV Efficiencies Beyond 50% http:www.compoundsemiconductor.net...

  17. Generalized Optoelectronic Model of Series-Connected Multijunction Solar Cells

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

    Geisz, John F.; Steiner, Myles A.; Garcia, Ivan; France, Ryan M.; McMahon, William E.; Osterwald, Carl R.; Friedman, Daniel J.

    2015-10-02

    The emission of light from each junction in a series-connected multijunction solar cell, we found, both complicates and elucidates the understanding of its performance under arbitrary conditions. Bringing together many recent advances in this understanding, we present a general 1-D model to describe luminescent coupling that arises from both voltage-driven electroluminescence and voltage-independent photoluminescence in nonideal junctions that include effects such as Sah-Noyce-Shockley (SNS) recombination with n ≠ 2, Auger recombination, shunt resistance, reverse-bias breakdown, series resistance, and significant dark area losses. The individual junction voltages and currents are experimentally determined from measured optical and electrical inputs and outputs ofmore » the device within the context of the model to fit parameters that describe the devices performance under arbitrary input conditions. Furthermore, our techniques to experimentally fit the model are demonstrated for a four-junction inverted metamorphic solar cell, and the predictions of the model are compared with concentrator flash measurements.« less

  18. Optically enhanced photon recycling in mechanically stacked multijunction solar cells

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

    Steiner, Myles A.; Geisz, John F.; Ward, J. Scott; Garcia, Ivan; Friedman, Daniel J.; King, Richard R.; Chiu, Philip T.; France, Ryan M.; Duda, Anna; Olavarria, Waldo J.; et al

    2015-11-09

    Multijunction solar cells can be fabricated by mechanically bonding together component cells that are grown separately. Here, we present four-junction four-terminal mechanical stacks composed of GaInP/GaAs tandems grown on GaAs substrates and GaInAsP/GaInAs tandems grown on InP substrates. The component cells were bonded together with a low-index transparent epoxy that acts as an angularly selective reflector to the GaAs bandedge luminescence, while simultaneously transmitting nearly all of the subbandgap light. As determined by electroluminescence measurements and optical modeling, the GaAs subcell demonstrates a higher internal radiative limit and, thus, higher subcell voltage, compared with GaAs subcells without the epoxy reflector.more » The best cells demonstrate 38.8 ± 1.0% efficiency under the global spectrum at 1000 W/m2 and ~ 42% under the direct spectrum at ~100 suns. As a result, eliminating the series resistance is the key challenge for further improving the concentrator cells.« less

  19. Optically enhanced photon recycling in mechanically stacked multijunction solar cells

    SciTech Connect (OSTI)

    Steiner, Myles A.; Geisz, John F.; Ward, J. Scott; Garcia, Ivan; Friedman, Daniel J.; King, Richard R.; Chiu, Philip T.; France, Ryan M.; Duda, Anna; Olavarria, Waldo J.; Young, Michelle; Kurtz, Sarah R.

    2015-11-09

    Multijunction solar cells can be fabricated by mechanically bonding together component cells that are grown separately. Here, we present four-junction four-terminal mechanical stacks composed of GaInP/GaAs tandems grown on GaAs substrates and GaInAsP/GaInAs tandems grown on InP substrates. The component cells were bonded together with a low-index transparent epoxy that acts as an angularly selective reflector to the GaAs bandedge luminescence, while simultaneously transmitting nearly all of the subbandgap light. As determined by electroluminescence measurements and optical modeling, the GaAs subcell demonstrates a higher internal radiative limit and, thus, higher subcell voltage, compared with GaAs subcells without the epoxy reflector. The best cells demonstrate 38.8 ± 1.0% efficiency under the global spectrum at 1000 W/m2 and ~ 42% under the direct spectrum at ~100 suns. As a result, eliminating the series resistance is the key challenge for further improving the concentrator cells.

  20. Non-Linear Luminescent Coupling in Series-Connected Multijunction Solar Cells

    SciTech Connect (OSTI)

    Steiner, M. A.; Geisz, J. F.

    2012-06-18

    The assumption of superposition or linearity of photocurrent with solar flux is widespread for calculations and measurements of solar cells. The well-known effect of luminescent coupling in multijunction solar cells has also been assumed to be linear with excess current. Here we show significant non-linearities in luminescent coupling in III-V multijunction solar cells and propose a simple model based on competition between radiative and nonradiative processes in the luminescent junction to explain these non-linearities. We demonstrate a technique for accurately measuring the junction photocurrents under a specified reference spectrum, that accounts for and quantifies luminescent coupling effects.

  1. A comparison of the radiation tolerance characteristics of multijunction solar cells with series and voltage-matched configurations

    SciTech Connect (OSTI)

    Gee, J.M; Curtis, H.B.

    1988-01-01

    The effect of series and voltage-matched configurations on the performance of multijunction solar cells in a radiation environment was investigated. It was found that the configuration of the multijunction solar cell can have a significant impact on its radiation tolerence characteristics.

  2. Design of Semiconductor-Based Back Reflectors for High Voc Monolithic Multijunction Solar Cells: Preprint

    SciTech Connect (OSTI)

    Garcia, I.; Geisz, J.; Steiner, M.; Olson, J.; Friedman, D.; Kurtz, S.

    2012-06-01

    State-of-the-art multijunction cell designs have the potential for significant improvement before going to higher number of junctions. For example, the Voc can be substantially increased if the photon recycling taking place in the junctions is enhanced. This has already been demonstrated (by Alta Devices) for a GaAs single-junction cell. For this, the loss of re-emitted photons by absorption in the underlying layers or substrate must be minimized. Selective back surface reflectors are needed for this purpose. In this work, different architectures of semiconductor distributed Bragg reflectors (DBR) are assessed as the appropriate choice for application in monolithic multijunction solar cells. Since the photon re-emission in the photon recycling process is spatially isotropic, the effect of the incident angle on the reflectance spectrum is of central importance. In addition, the DBR structure must be designed taking into account its integration into the monolithic multijunction solar cells, concerning series resistance, growth economics, and other issues. We analyze the tradeoffs in DBR design complexity with all these requirements to determine if such a reflector is suitable to improve multijunction solar cells.

  3. NREL's Multi-Junction Solar Cells Teach Scientists How to Turn Plants into

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

    Powerhouses - News Releases | NREL NREL's Multi-Junction Solar Cells Teach Scientists How to Turn Plants into Powerhouses May 12, 2011 Plants can overcome their evolutionary legacies to become much better at using biological photosynthesis to produce energy, the kind of energy that can power vehicles in the near future, an all-star collection of biologists, physicists, photochemists, and solar scientists has found. A U.S. Department of Energy (DOE) workshop that drew a prestigious collection

  4. Boosting Accuracy of Testing Multijunction Solar Cells (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2015-01-01

    This NREL Highlight describes research into a more precise technology for measuring efficiency of concentrating solar cells, which will enable the industry to advance.

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

    SciTech Connect (OSTI)

    Meerheim, Rico Krner, 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.

  6. Laboratory instrumentation and techniques for characterizing multi-junction solar cells for space applications

    SciTech Connect (OSTI)

    Woodyard, J.R.

    1995-10-01

    Multi-junction solar cells are attractive for space applications because they can be designed to convert a larger fraction of AMO into electrical power at a lower cost than single-junction cells. The performance of multi-junction cells is much more sensitive to the spectral irradiance of the illuminating source than single-junction cells. The design of high efficiency multi-junction cells for space applications requires matching the optoelectronic properties of the junctions to AMO spectral irradiance. Unlike single-junction cells, it is not possible to carry out quantum efficiency measurements using only a monochromatic probe beam and determining the cell short-circuit current assuming linearity of the quantum efficiency. Additionally, current-voltage characteristics can not be calculated from measurements under non-AMO light sources using spectral-correction methods. There are reports in the literature on characterizing the performance of multi junction cells by measuring and convoluting the quantum efficiency of each junction with the spectral irradiance; the technique is of limited value for the characterization of cell performance under AMO power-generating conditions. The authors report the results of research to develop instrumentation and techniques for characterizing multi junction solar cells for space . An integrated system is described which consists of a standard lamp, spectral radiometer, dual-source solar simulator, and personal computer based current-voltage and quantum efficiency equipment. The spectral radiometer is calibrated regularly using the tungsten-halogen standard lamp which has a calibration based on NIST scales. The solar simulator produces the light bias beam for current-voltage and cell quantum efficiency measurements. The calibrated spectral radiometer is used to `fit` the spectral irradiance of the dual-source solar simulator to WRL AMO data.

  7. NREL Scientists Spurred the Success of Multijunction Solar Cells (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2012-09-01

    Before 1984, many scientists believed that high-quality gallium indium phosphide (GaInP) alloys could not be grown for use as semiconductors because the alloys would separate. One researcher at the Solar Energy Research Institute (SERI) thought differently. His name was Jerry Olson, and his innovative thinking changed solar history. Olson identified a material combination that allowed the multijunction cell to flourish. It is now the workhorse that powers satellites and the catalyst for renewed interest in concentrator photovoltaic (CPV) products.

  8. A high intensity solar cell invention: The edge-illuminated vertical multi-junction (VNJ) solar cell

    SciTech Connect (OSTI)

    Sater, B.L.

    1992-08-07

    This report contains a summary of a High Intensity Solar Cell (HI Cell) development carried out under the NIST/DOE Energy-Related Invention Program. The HI Cell, or Edge-Illuminated vertical Multi-junction Solar Cell, eliminates most major problems encountered with other concentrator solar cell designs. Its high voltage and low series resistance features make it ideally suited for efficient operation at high intensities. Computer modeling shows efficiencies near 30% at 500 suns intensity are possible with state-of-art processing. Development of a working model was largely successful before encountering an unexpected problem during the last fabrication step with the anti-reflection coating. Unfortunately, funding was exhausted before its resolution. Recommendations are made to resolve the AR coating problem and to integrate all the knowledge gained during this development into a viable prototype model. The invention will provide the technical and economic performance needed to make photovoltaic systems cost-effective for wide use.

  9. A high intensity solar cell invention: The edge-illuminated vertical multi-junction (VNJ) solar cell. Final report

    SciTech Connect (OSTI)

    Sater, B.L.

    1992-08-07

    This report contains a summary of a High Intensity Solar Cell (HI Cell) development carried out under the NIST/DOE Energy-Related Invention Program. The HI Cell, or Edge-Illuminated vertical Multi-junction Solar Cell, eliminates most major problems encountered with other concentrator solar cell designs. Its high voltage and low series resistance features make it ideally suited for efficient operation at high intensities. Computer modeling shows efficiencies near 30% at 500 suns intensity are possible with state-of-art processing. Development of a working model was largely successful before encountering an unexpected problem during the last fabrication step with the anti-reflection coating. Unfortunately, funding was exhausted before its resolution. Recommendations are made to resolve the AR coating problem and to integrate all the knowledge gained during this development into a viable prototype model. The invention will provide the technical and economic performance needed to make photovoltaic systems cost-effective for wide use.

  10. 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.

  11. A 2-terminal perovskite/silicon multijunction solar cell enabled by a silicon tunnel junction

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

    Mailoa, Jonathan P.; Bailie, Colin D.; Johlin, Eric C.; Hoke, Eric T.; Akey, Austin J.; Nguyen, William H.; McGehee, Michael D.; Buonassisi, Tonio

    2015-03-24

    With the advent of efficient high-bandgap metal-halide perovskite photovoltaics, an opportunity exists to make perovskite/silicon tandem solar cells. We fabricate a monolithic tandem by developing a silicon-based interband tunnel junction that facilitates majority-carrier charge recombination between the perovskite and silicon sub-cells. We demonstrate a 1 cm2 2-terminal monolithic perovskite/silicon multijunction solar cell with a VOC as high as 1.65 V. As a result, we achieve a stable 13.7% power conversion efficiency with the perovskite as the current-limiting sub-cell, and identify key challenges for this device architecture to reach efficiencies over 25%.

  12. A 2-terminal perovskite/silicon multijunction solar cell enabled by a silicon tunnel junction

    SciTech Connect (OSTI)

    Mailoa, Jonathan P.; Bailie, Colin D.; Johlin, Eric C.; Hoke, Eric T.; Akey, Austin J.; Nguyen, William H.; McGehee, Michael D.; Buonassisi, Tonio

    2015-03-24

    With the advent of efficient high-bandgap metal-halide perovskite photovoltaics, an opportunity exists to make perovskite/silicon tandem solar cells. We fabricate a monolithic tandem by developing a silicon-based interband tunnel junction that facilitates majority-carrier charge recombination between the perovskite and silicon sub-cells. We demonstrate a 1 cm2 2-terminal monolithic perovskite/silicon multijunction solar cell with a VOC as high as 1.65 V. As a result, we achieve a stable 13.7% power conversion efficiency with the perovskite as the current-limiting sub-cell, and identify key challenges for this device architecture to reach efficiencies over 25%.

  13. High-Intensity Silicon Vertical Multi-Junction Solar Cells |...

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

    ... Versatility Can be used in ground-mounted and roof-mounted deployments. Contact Information Mico Perales (216) 535-9200 mico.perales@greenfieldsolar.com GreenField Solar ...

  14. Study of minority carrier diffusion lengths in photoactive layers of multijunction solar cells

    SciTech Connect (OSTI)

    Mintairov, S. A. Andreev, V. M.; Emelyanov, V. M.; Kalyuzhnyy, N. A.; Timoshina, N. K.; Shvarts, M. Z.; Lantratov, V. M.

    2010-08-15

    A technique for determining a minority carrier's diffusion length in photoactive III-V layers of solar cells by approximating their spectral characteristics is presented. Single-junction GaAs, Ge and multi-junction GaAs/Ge, GaInP/GaAs, and GaInP/GaInAs/Ge solar cells fabricated by hydride metal-organic vapor-phase epitaxy (H-MOVPE) have been studied. The dependences of the minority carrier diffusion length on the doping level of p-Ge and n-GaAs are determined. It is shown that the parameters of solid-state diffusion of phosphorus atoms to the p-Ge substrate from the n-GaInP nucleation layer are independent of the thickness of the latter within 35-300 nm. It is found that the diffusion length of subcells of multijunction structures in Ga(In)As layers is smaller in comparison with that of single-junction structures.

  15. Increased efficiency in multijunction solar cells through the incorporation of semimetallic ErAs nanoparticles into the tunnel junction

    SciTech Connect (OSTI)

    Zide, J.M.O.; Kleiman-Shwarsctein, A.; Strandwitz, N.C.; Zimmerman, J.D.; Steenblock-Smith, T.; Gossard, A.C.; Forman, A.; Ivanovskaya, A.; Stucky, G.D.

    2006-04-17

    We report the molecular beam epitaxy growth of Al{sub 0.3}Ga{sub 0.7}As/GaAs multijunction solar cells with epitaxial, semimetallic ErAs nanoparticles at the interface of the tunnel junction. The states provided by these nanoparticles reduce the bias required to pass current through the tunnel junction by three orders of magnitude, and therefore drastically reduce the voltage losses in the tunnel junction. We have measured open-circuit voltages which are 97% of the sum of the constituent cells, which result in nearly double the efficiency of our multijunction cell with a conventional tunnel junction.

  16. High performance anti-reflection coatings for broadband multi-junction solar cells

    SciTech Connect (OSTI)

    AIKEN,DANIEL J.

    2000-02-23

    The success of bandgap engineering has made high efficiency broadband multi-junction solar cells possible with photo-response out to the band edge of Ge. Modeling has been conducted which suggests that current double layer anti-reflection coating technology is not adequate for these devices in certain cases. Approaches for the development of higher performance anti-reflection coatings are examined. A new AR coating structure based on the use of Herpin equivalent layers is presented. Optical modeling suggests a decrease in the solar weighted reflectance of over 2.5{percent} absolute as a result. This structure requires no additional optical material development and characterization because no new optical materials are necessary. Experimental results and a sensitivity analysis are presented.

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

    DOE Patents [OSTI]

    Olson, Jerry M.; Kurtz, Sarah R.

    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

  18. Progress toward technology transition of GaInP{sub 2}/GaAs/Ge multijunction solar cells

    SciTech Connect (OSTI)

    Keener, D.N.; Marvin, D.C.; Brinker, D.J.; Curtis, H.B.; Price, P.M.

    1997-12-31

    The objective of the joint WL/PL/NASA Multijunction Solar Cell Manufacturing Technology (ManTech) Program is to scale up high efficiency GaInP{sub 2}/GaAs/Ge multijunction solar cells to production size, quantity, and yield while limiting the production cost/Watt ($/W) to 15% over GaAs cells. Progress made by the program contractors, Spectrolab and TECSTAR, include, respectively, best cell efficiencies of 25.76% and 24.7% and establishment of 24.2% and 23.8% lot average efficiency baseline designs. The paper also presents side-by-side testing results collected by Phillips Laboratory and NASA Lewis on Phase 1 deliverable cells, which shows compliance with program objectives. Cell performance, pre- and post-radiation, and temperature coefficient results on initial production GaInP{sub 2}/GaAs/Ge solar cells will be presented.

  19. Comparison of Theoretical Efficiencies of Multi-junction Concentrator Solar Cells

    SciTech Connect (OSTI)

    Kurtz, S.; Myers, D.; McMahon, W. E.; Geisz, J.; Steiner, M.

    2008-01-01

    Champion concentrator cell efficiencies have surpassed 40% and now many are asking whether the efficiencies will surpass 50%. Theoretical efficiencies of >60% are described for many approaches, but there is often confusion about the theoretical efficiency for a specific structure. The detailed balance approach to calculating theoretical efficiency gives an upper bound that can be independent of material parameters and device design. Other models predict efficiencies that are closer to those that have been achieved. Changing reference spectra and the choice of concentration further complicate comparison of theoretical efficiencies. This paper provides a side-by-side comparison of theoretical efficiencies of multi-junction solar cells calculated with the detailed balance approach and a common one-dimensional-transport model for different spectral and irradiance conditions. Also, historical experimental champion efficiencies are compared with the theoretical efficiencies.

  20. 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.

  1. Temperature-Dependent Measurements of an Inverted Metamorphic Multijunction (IMM) Solar Cell: Preprint

    SciTech Connect (OSTI)

    Steiner, M. A.; Geisz, J. F.; Friedman, D. J.; Olavarria, W. J.; Duda, A.; Moriarty, T. E.

    2011-07-01

    The inverted metamorphic multijunction (IMM) solar cell has demonstrated efficiencies as high as 40.8% at 25 degrees C and 326 suns concentration. The actual operating temperature in a commercial module, however, is likely to be as much as 50-70 degrees C hotter, reaching as high as 100 degrees C. In order to be able to evaluate the cell performance under these real-world operating conditions, we have measured the open-circuit voltage, short-circuit current density and efficiency at temperatures up to 125 degrees C and concentrations up to 1000 suns, as well as the temperature coefficients of these parameters. Spectral response and one-sun current-voltage characteristics were measured by carefully adjusting the incident spectrum to selectively current-limit the different subcells. Concentrator measurements were taken on a pulsed solar simulator to minimize any additional heating due to the high intensity illumination. We compare our measured values to predictions based on detailed models of various triple junction solar cells. By choosing the optimum bandgaps for high temperature operation, the IMM can potentially result in greater energy production and lower temperature sensitivity under real operating conditions than a Ge-based solar cell.

  2. Temperature-Dependent Measurements of an Inverted Metamorphic Multijunction (IMM) Solar Cell

    SciTech Connect (OSTI)

    Steiner, M. A.; Geisz, J. F.; Friedman, D. J.; Olavarria, W. J.; Duda, A.; Moriarty, T. E.

    2011-01-01

    The inverted metamorphic multijunction (IMM) solar cell has demonstrated efficiencies as high as 40.8% at 25 C and 326 suns concentration. The actual operating temperature in a commercial module, however, is likely to be as much as 50-70 C hotter, reaching as high as 100 C. In order to be able to evaluate the cell performance under these real-world operating conditions, we have measured the open-circuit voltage, short-circuit current density and efficiency at temperatures up to 125 C and concentrations up to 1000 suns, as well as the temperature coefficients of these parameters. Spectral response and one-sun current-voltage characteristics were measured by carefully adjusting the incident spectrum to selectively current-limit the different subcells. Concentrator measurements were taken on a pulsed solar simulator to minimize any additional heating due to the high intensity illumination. We compare our measured values to predictions based on detailed models of various triple junction solar cells. By choosing the optimum bandgaps for high temperature operation, the IMM can potentially result in greater energy production and lower temperature sensitivity under real operating conditions than a Ge-based solar cell.

  3. Stable a-Si:H Based Multijunction Solar Cells with Guidance from Real Time Optics: Annual Report, Phase I: 17 July 1998-16 October 1999

    SciTech Connect (OSTI)

    Wronski, C.R.; Collins, R.W.; Jiao, L.; Ferlauto, A.; Rovira, P.I.; Koval, R.J.; Lu, Z.; Niu, X.

    2000-08-29

    This summary describes tasks of novel improved intrinsic materials for multijunction solar cells, insights into improved stability in materials and solar cells, optimization of solar cell performance with improved intrinsic layers, and optimization of multijunction solar cells. The report characterizes a protocrystalline a-Si:H film growth regime where thin samples retain their amorphous state when their growth time or thickness is limited to small values, even when films are deposited with high hydrogen dilution that results in microcrystalline thick films. The Staebler-Wronski degradation kinetics of films and devices are systematically studied as a function of hydrogen dilution.

  4. Advances on multijunction solar cell characterization aimed at the optimization of real concentrator performance

    SciTech Connect (OSTI)

    Garcia-Linares, Pablo Dominguez, César Voarino, Philippe Besson, Pierre Baudrit, Mathieu

    2014-09-26

    Multijunction solar cells (MJSC) are usually developed to maximize efficiency under test conditions and not under real operation. This is the case of anti-reflective coatings (ARC), which are meant to minimize Fresnel reflection losses for a family of incident rays at room temperature. In order to understand and quantify the discrepancies between test and operation conditions, we have experimentally analyzed the spectral response of MJSC for a variety of incidence angles that are in practice received by a concentrator cell in high-concentration photovoltaic (HCPV) receiver designs. Moreover, we characterize this angular dependence as a function of temperature in order to reproduce real operation conditions. As the refractive index of the silicone is dependent on temperature, an optical mismatch is expected. Regarding other characterization techniques, a method called Relative EL Homogeneity Analysis (RELHA) is applied to processed wafers prior to dicing, allowing to diagnose the wafer crystalline homogeneity for each junction. Finally, current (I)-voltage (V) characterization under strongly unbalanced light spectra has also been carried out for a number of low-level irradiances, providing insight on each junction shunt resistance and corresponding radiative coupling.

  5. Nanostructure Arrays for Multijunction Solar Cells: Final Subcontract Report, 12 May 1999--11 July 2002

    SciTech Connect (OSTI)

    Das, B.

    2004-06-01

    This project developed the process technologies for the fabrication of high-efficiency multijunction photovoltaic cells using semiconductor nanostructure arrays. These devices are expected to provide increased energy conversion efficiency, as well as increased carrier collection efficiency. In addition, this approach provides the ability to tune the absorption spectrum to match selected windows of the solar spectrum. At the same time, these devices can be fabricated using existing industrial electrochemical processing techniques that can substantially reduce the cost of each device. The fabrication technique is based on electrochemical synthesis of II-VI semiconductor quantum wires using a preformed alumina template. This project focused on and solved the technical challenges that need to be addressed for the implementation of such devices. Specific issues addressed include (a) improved pore ordering on thin-film templates, (b) synthesis of II-VI semiconductor nanostructures by both AC and DC deposition, (c) an in-situ barrier-layer engineering process that allow the fabrication of superior-quality materials and improved template/substrate interface, (d) characterization techniques for templates, (e) process technology for creating stacked layers of nanostructures, (f) process throughput and improved apparatus, (g) modeling tools, (h) use of glass substrates, and (i) a nonlithographic surface texturing technique for silicon PV cells. An important outcome of this project is the demonstration of the fabrication technique on glass substrates. This breakthrough provides the possibility of covering buildings with''transparent'' solar cells fabricated on architectural glass. The accomplishments of this project position it well for the next phase of research, namely, creation and optimization of the nanostructure-based PV cells.

  6. InGaAsN/GaAs heterojunction for multi-junction solar cells

    DOE Patents [OSTI]

    Kurtz, Steven R.; Allerman, Andrew A.; Klem, John F.; Jones, Eric D.

    2001-01-01

    An InGaAsN/GaAs semiconductor p-n heterojunction is disclosed for use in forming a 0.95-1.2 eV bandgap photodetector with application for use in high-efficiency multi-junction solar cells. The InGaAsN/GaAs p-n heterojunction is formed by epitaxially growing on a gallium arsenide (GaAs) or germanium (Ge) substrate an n-type indium gallium arsenide nitride (InGaAsN) layer having a semiconductor alloy composition In.sub.x Ga.sub.1-x As.sub.1-y N.sub.y with 070%.

  7. Estimation of the potential efficiency of a multijunction solar cell at a limit balance of photogenerated currents

    SciTech Connect (OSTI)

    Mintairov, M. A. Evstropov, V. V.; Mintairov, S. A.; Shvarts, M. Z.; Timoshina, N. Kh.; Kalyuzhnyy, N. A.

    2015-05-15

    A method is proposed for estimating the potential efficiency which can be achieved in an initially unbalanced multijunction solar cell by the mutual convergence of photogenerated currents: to extract this current from a relatively narrow band-gap cell and to add it to a relatively wide-gap cell. It is already known that the properties facilitating relative convergence are inherent to such objects as bound excitons, quantum dots, donor-acceptor pairs, and others located in relatively wide-gap cells. In fact, the proposed method is reduced to the problem of obtaining such a required light current-voltage (I–V) characteristic which corresponds to the equality of all photogenerated short-circuit currents. Two methods for obtaining the required light I–V characteristic are used. The first one is selection of the spectral composition of the radiation incident on the multijunction solar cell from an illuminator. The second method is a double shift of the dark I–V characteristic: a current shift J{sub g} (common set photogenerated current) and a voltage shift (−J{sub g}R{sub s}), where R{sub s} is the series resistance. For the light and dark I–V characteristics, a general analytical expression is derived, which considers the effect of so-called luminescence coupling in multijunction solar cells. The experimental I–V characteristics are compared with the calculated ones for a three-junction InGaP/GaAs/Ge solar cell with R{sub s} = 0.019 Ω cm{sup 2} and a maximum factual efficiency of 36.9%. Its maximum potential efficiency is estimated as 41.2%.

  8. Chemical beam epitaxy growth of AlGaAs/GaAs tunnel junctions using trimethyl aluminium for multijunction solar cells

    SciTech Connect (OSTI)

    Paquette, B.; DeVita, M.; Turala, A.; Kolhatkar, G.; Boucherif, A.; Jaouad, A.; Aimez, V.; Ars, R.; Wilkins, M.; Wheeldon, J. F.; Walker, A. W.; Hinzer, K.; Fafard, S.

    2013-09-27

    AlGaAs/GaAs tunnel junctions for use in high concentration multijunction solar cells were designed and grown by chemical beam epitaxy (CBE) using trimethyl aluminium (TMA) as the p-dopant source for the AlGaAs active layer. Controlled hole concentration up to 4?10{sup 20} cm{sup ?3} was achieved through variation in growth parameters. Fabricated tunnel junctions have a peak tunneling current up to 6140 A/cm{sup 2}. These are suitable for high concentration use and outperform GaAs/GaAs tunnel junctions.

  9. AlGaAs/InGaAlP tunnel junctions for multijunction solar cells

    SciTech Connect (OSTI)

    SHARPS,P.R.; LI,N.Y.; HILLS,J.S.; HOU,H.; CHANG,PING-CHIH; BACA,ALBERT G.

    2000-05-16

    Optimization of GaInP{sub 2}/GaAs dual and GaInP{sub 2}/GaAs/Ge triple junction cells, and development of future generation monolithic multi-junction cells will involve the development of suitable high bandgap tunnel junctions. There are three criteria that a tunnel junction must meet. First, the resistance of the junction must be kept low enough so that the series resistance of the overall device is not increased. For AMO, 1 sun operation, the tunnel junction resistance should be below 5 x 10{sup {minus}2} {Omega}-cm. Secondly, the peak current density for the tunnel junction must also be larger than the J{sub sc} of the cell so that the tunnel junction I-V curve does not have a deleterious effect on the I-V curve of the multi-junction device. Finally, the tunnel junction must be optically transparent, i.e., there must be a minimum of optical absorption of photons that will be collected by the underlying subcells. The paper reports the investigation of four high bandgap tunnel junctions grown by metal-organic chemical vapor deposition.

  10. High-performance broadband optical coatings on InGaN/GaN solar cells for multijunction device integration

    SciTech Connect (OSTI)

    Young, N. G. Farrell, R. M.; Iza, M.; Speck, J. S.; Perl, E. E.; Keller, S.; Bowers, J. E.; Nakamura, S.; DenBaars, S. P.

    2014-04-21

    We demonstrate InGaN/GaN multiple quantum well solar cells grown by metalorganic chemical vapor deposition on a bulk (0001) substrate with high-performance broadband optical coatings to improve light absorption. A front-side anti-reflective coating and a back-side dichroic mirror were designed to minimize front surface reflections across a broad spectral range and maximize rear surface reflections only in the spectral range absorbed by the InGaN, making the cells suitable for multijunction solar cell integration. Application of optical coatings increased the peak external quantum efficiency by 56% (relative) and conversion efficiency by 37.5% (relative) under 1 sun AM0 equivalent illumination.

  11. Effect of Dual-Function Nano-Structured Silicon Oxide Thin Film on Multi-Junction Solar Cells

    SciTech Connect (OSTI)

    Yan, B.; Sivec, L.; Yue, G.; Jiang, C. S.; Yang, J.; Guha, S.

    2011-01-01

    We present our recent study of using nano-structured hydrogenated silicon oxide films (nc-SiO{sub x}:H) as a dual-function layer in multi-junction solar cells. The nc-SiO{sub x}:H films were deposited using very high frequency glow discharge of a SiH{sub 4} (or Si{sub 2}H{sub 6}), CO{sub 2}, PH{sub 3}, and H{sub 2} gas mixture. By optimizing deposition parameters, we obtained 'dual function' nc-SiO{sub x}:H material characterized by a conductivity suitable for use as an n layer and optical properties suitable for use as an inter-reflection layer. We tested the nc-SiO{sub x}:H by replacing the normal n-type material in the tunnel junction of a multi-junction structure. The advantage of the dual-function nc-SiO{sub x}:H layer is twofold; one is to simplify the cell structure, and the other is to reduce any optical loss associated with the inter-reflection layer. Quantum efficiency measurements show the gain in top cell current is equal to or greater than the loss in bottom cell current for a-Si:H/nc-Si:H structures. In addition, a thinner a-Si:H top cell with the nc-SiO{sub x}:H n layer improves the top-cell stability, thereby providing higher stabilized solar cell efficiency. We also used the dual-function layer between the middle and the bottom cells in a-Si:H/a-SiGe:H/nc-Si:H triple-junction structures. The gain in the middle cell current is {approx}1.0 mA/cm{sup 2}, leading to an initial active-area efficiency of 14.8%.

  12. 100 mm Engineered InP-on-Si Laminate Substrates for InP-based Multijunction Solar Cells

    SciTech Connect (OSTI)

    Atwater, Harry

    2012-06-25

    The project focused on fabrication of InP/Si laminate substrates as templates for growth of InGaAsP/InGaAs and InAlAs/InGaAsP/InGaAs multijunction solar cells. InP/Si template substrates were developed and used as templates for InGaAs solar growth. A novel feature of the program was development of the virtual substrate template, which enables a substrate to be formed with a lattice constant intermediate between those of GaAs and InP. Large-area virtual substrate templates were formed by transfer and bonding of dislocation free InGaAs films wafer onto silicon substrates.

  13. Multi-junction, monolithic solar cell using low-band-gap materials lattice matched to GaAs or Ge

    DOE Patents [OSTI]

    Olson, Jerry M.; Kurtz, Sarah R.; Friedman, Daniel J.

    2001-01-01

    A multi-junction, monolithic, photovoltaic solar cell device is provided for converting solar radiation to photocurrent and photovoltage with improved efficiency. The solar cell device comprises a plurality of semiconductor cells, i.e., active p/n junctions, connected in tandem and deposited on a substrate fabricated from GaAs or Ge. To increase efficiency, each semiconductor cell is fabricated from a crystalline material with a lattice constant substantially equivalent to the lattice constant of the substrate material. Additionally, the semiconductor cells are selected with appropriate band gaps to efficiently create photovoltage from a larger portion of the solar spectrum. In this regard, one semiconductor cell in each embodiment of the solar cell device has a band gap between that of Ge and GaAs. To achieve desired band gaps and lattice constants, the semiconductor cells may be fabricated from a number of materials including Ge, GaInP, GaAs, GaInAsP, GaInAsN, GaAsGe, BGaInAs, (GaAs)Ge, CuInSSe, CuAsSSe, and GaInAsNP. To further increase efficiency, the thickness of each semiconductor cell is controlled to match the photocurrent generated in each cell. To facilitate photocurrent flow, a plurality of tunnel junctions of low-resistivity material are included between each adjacent semiconductor cell. The conductivity or direction of photocurrent in the solar cell device may be selected by controlling the specific p-type or n-type characteristics for each active junction.

  14. Multi-crystalline II-VI based multijunction solar cells and modules

    SciTech Connect (OSTI)

    Hardin, Brian E.; Connor, Stephen T.; Groves, James R.; Peters, Craig H.

    2015-06-30

    Multi-crystalline group II-VI solar cells and methods for fabrication of same are disclosed herein. A multi-crystalline group II-VI solar cell includes a first photovoltaic sub-cell comprising silicon, a tunnel junction, and a multi-crystalline second photovoltaic sub-cell. A plurality of the multi-crystalline group II-VI solar cells can be interconnected to form low cost, high throughput flat panel, low light concentration, and/or medium light concentration photovoltaic modules or devices.

  15. III-V Growth on Silicon Toward a Multijunction Cell

    SciTech Connect (OSTI)

    Geisz, J.; Olson, J.; McMahon, W.; Friedman, D.; Kibbler, A.; Kramer, C.; Young, M.; Duda, A.; Ward, S.; Ptak, A.; Kurtz, S.; Wanlass, M.; Ahrenkiel, P.; Jiang, C. S.; Moutinho, H.; Norman, A.; Jones, K.; Romero, M.; Reedy, B.

    2005-11-01

    A III-V on Si multijunction solar cell promises high efficiency at relatively low cost. The challenges to epitaxial growth of high-quality III-Vs on Si, though, are extensive. Lattice-matched (LM) dilute-nitride GaNPAs solar cells have been grown on Si, but their performance is limited by defects related to the nitrogen. Advances in the growth of lattice-mismatched (LMM) materials make more traditional III-Vs, such as GaInP and GaAsP, very attractive for use in multijunction solar cells on silicon.

  16. Phase transformations during the Ag-In plating and bonding of vertical diode elements of multijunction solar cells

    SciTech Connect (OSTI)

    Klochko, N. P. Khrypunov, G. S.; Volkova, N. D.; Kopach, V. R.; Lyubov, V. N.; Kirichenko, M. V.; Momotenko, A. V.; Kharchenko, N. M.; Nikitin, V. A.

    2013-06-15

    The conditions of the bonding of silicon multijunction solar cells with vertical p-n junctions using Ag-In solder are studied. The compositions of electrodeposited indium films on silicon wafers silver plated by screen printing and silver and indium films fabricated by layer-by-layer electrochemical deposition onto the surface of silicon vertical diode cells silver plated in vacuum are studied. Studying the electrochemical-deposition conditions, structure, and surface morphology of the grown layers showed that guaranteed bonding is provided by 8-min heat treatment at 400 Degree-Sign C under the pressure of a stack of metallized silicon wafers; however, the ratio of the indium and silver layer thicknesses should not exceed 1: 3. As this condition is satisfied, the solder after wafer bonding has the InAg{sub 3} structure (or InAg{sub 3} with an Ag phase admixture), due to which the junction melting point exceeds 700 Degree-Sign C, which guarantees the functioning of such solar cells under concentrated illumination.

  17. Measurement of multijunction cells under close-match conditions

    SciTech Connect (OSTI)

    Wilkinson, V.A.; Goodbody, C.; Williams, W.G.

    1997-12-31

    This paper presents details of a new close-match solar simulator developed for DERA`s Space Power Laboratory for the accurate characterization of multijunction solar cells. The authors present data on the simulator measurements of dual and triple junction cells. The measurements are compared with those made under less ideal spectral conditions.

  18. Light-Biasing Electron-Beam-Induced-Current Measurements for Multijunction Solar Cells: Preprint

    SciTech Connect (OSTI)

    Romero, M. J.; Olson, J. M.; Al-Jassim, M. M.

    2001-10-01

    Presented at the 2001 NCPV Program Review Meeting: Results using light-biasing EBIC are illustrated for dual-junction InGaP/InGaAs solar cells.

  19. Procedures at NREL for Evaluating Multijunction Concentrator Cells

    SciTech Connect (OSTI)

    Moriarty, T.; Emery, K.

    2000-01-01

    The procedures for evaluating the performance of multijunctiion-concentrator cells at the National Renewable Energy Laboratory are described. The accurate measurement of the performance of multijunction cells requires accurate relative-quantum-efficiency-measurements, "matched" reference cells, and a spectrally adjustable solar simulator.

  20. 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.

  1. Multijunction GaInP/GaInAs/Ge solar cells with Bragg reflectors

    SciTech Connect (OSTI)

    Emelyanov, V. M. Kalyuzhniy, N. A.; Mintairov, S. A.; Shvarts, M. Z.; Lantratov, V. M.

    2010-12-15

    Effect of subcell parameters on the efficiency of GaInP/Ga(In)As/Ge tandem solar cells irradiated with 1-MeV electrons at fluences of up to 3 x 10{sup 15} cm{sup -2} has been theoretically studied. The optimal thicknesses of GaInP and GaInAs subcells, which provide the best photocurrent matching at various irradiation doses in solar cells with and without built-in Bragg reflectors, were determined. The dependences of the photoconverter efficiency on the fluence of 1-MeV electrons and on the time of residence in the geostationary orbit were calculated for structures optimized to the beginning and end of their service lives. It is shown that the optimization of the subcell heterostructures for a rated irradiation dose and the introduction of Bragg reflectors into the structure provide a 5% overall increase in efficiency for solar cells operating in the orbit compared with unoptimized cells having no Bragg reflector.

  2. Luminescence based series resistance mapping of III-V multijunction solar cells

    SciTech Connect (OSTI)

    Nesswetter, Helmut; Dyck, Wilhelm; Lugli, Paolo; Bett, Andreas W.; Zimmermann, Claus G.

    2013-11-21

    A method to measure the series resistance of Ga{sub 0.5}In{sub 0.5}P/Ga(In)As/Ge triple-junction solar cells spatially resolved is developed, based on luminescence imaging. With the help of network simulations, the dependence of the local series resistance on the external subcell illumination intensities and biasing voltage is predicted and the optimum measurement conditions are clarified. Experimentally, specially prepared test cells with partially irradiated areas are used to verify the capabilities of the method. It is shown that the method is not sensitive to variations of the dark IV parameters of the subcells.

  3. Profiling the Built-In Electrical Potential in III-V Multijunction Solar Cells (Poster)

    SciTech Connect (OSTI)

    Jiang, C.-S.; Friedman, D. J.; Moutinho, H. R.; Al-Jassim, M. M.

    2006-05-01

    We have observed three electrical potentials at the top, tunneling, and bottom junctions of GnInP{sub 2}/GaAs tandem-junction solar cells, by performing the UHV-SKPM measurement. The effect of laser illumination was avoided by using GaAs laser with photon energy of 1.4 eV for the AFM operation. We also observed higher potentials at the atomic steps than on the terraces for both p-type GaInP{sub 2} epitaxial layer and p-type GaAs substrate, and found that the potential at steps of GaAs substrate depends on the step directions.

  4. Germanium subcells for multijunction GaInP/GaInAs/Ge solar cells

    SciTech Connect (OSTI)

    Kalyuzhnyy, N. A.; Gudovskikh, A. S.; Evstropov, V. V.; Lantratov, V. M.; Mintairov, S. A.; Timoshina, N. Kh.; Shvarts, M. Z.; Andreev, V. M.

    2010-11-15

    Photovoltaic converters based on n-GaInP/n-p-Ge heterostructures grown by the OMVPE under different conditions of formation of the p-n junction are studied. The heterostructures are intended for use as narrow-gap subcells of the GaInP/GaInAs/Ge three-junction solar cells. It is shown that, in Ge p-tn junctions, along with the diffusion mechanism, the tunneling mechanism of the current flow exists; therefore, the two-diode electrical equivalent circuit of the Ge p-n junction is used. The diode parameters are determined for both mechanisms from the analysis of both dark and 'light' current-voltage dependences. It is shown that the elimination of the component of the tunneling current allows one to increase the efficiency of the Ge subcell by {approx}1% with conversion of nonconcentrated solar radiation. The influence of the tunneling current on the efficiency of the Ge-based devices can be in practice reduced to zero at photogenerated current density of {approx}1.5 A/cm{sup 2} due to the use of the concentrated solar radiation.

  5. Profiling the Built-In Electrical Potential in III-V Multijunction Solar Cells

    SciTech Connect (OSTI)

    Jiang, C.-S.; Friedman, D. J.; Moutinho, H. R.; Al-Jassim, M. M.

    2006-01-01

    We report on a direct measurement of the electrical potential on cross-sections of GaInP{sub 2}/GaAs multiple-junction solar cells by using an ultrahigh-vacuum scanning Kelvin probe microscope (UHV-SKPM). The UHV-SKPM allows us to measure the potential without air molecules being adsorbed on the cross-sectional surface. Moreover, it uses a GaAs laser with photon energy of 1.4 eV for the atomic force microscope (AFM) operation. This eliminated the light-absorption-induced bottom-junction flattening and top-junction enhancement, which happened in our previous potential measurement using a 1.85-eV laser for the AFM operation. Three potentials were measured at the top, tunneling, and bottom junctions. Values of the potentials are smaller than the potentials in the bulk. This indicates that the Fermi level on the UHV-cleaved (110) surface was pinned, presumably due to defects upon cleaving. We also observed higher potentials at atomic steps than on the terraces for both GaInP2 epitaxial layer and GaAs substrate. Combining scanning tunneling microscopy (STM) and SKPM measurements, we found that the potential height at steps of the GaAs substrate depends on the step direction, which is probably a direct result of unbalanced cations and anions at the steps.

  6. Profiling the Built-in Electrical Potential in III-V Multijunction Solar Cells: Preprint

    SciTech Connect (OSTI)

    Jiang, C.-S.; Friedman, D. J.; Moutinho, H. R.; Al-Jassim, M. M.

    2006-05-01

    We report on a direct measurement of the electrical potential on cross-sections of GaInP2/GaAs multiple-junction solar cells by using an ultrahigh-vacuum scanning Kelvin probe microscope (UHV-SKPM). The UHV-SKPM allows us to measure the potential without air molecules being adsorbed on the cross-sectional surface. Moreover, it uses a GaAs laser with photon energy of 1.4 eV for the atomic force microscope (AFM) operation. This eliminated the light-absorption-induced bottom-junction flattening and top-junction enhancement, which happened in our previous potential measurement using a 1.85-eV laser for the AFM operation. Three potentials were measured at the top, tunneling, and bottom junctions. Values of the potentials are smaller than the potentials in the bulk. This indicates that the Fermi level on the UHV-cleaved (110) surface was pinned, presumably due to defects upon cleaving. We also observed higher potentials at atomic steps than on the terraces for both GaInP2 epitaxial layer and GaAs substrate. Combining scanning tunneling microscopy (STM) and SKPM measurements, we found that the potential height at steps of the GaAs substrate depends on the step direction, which is probably a direct result of unbalanced cations and anions at the steps.

  7. Optimized III-V Multijunction Concentrator Solar Cells on Patterned Si and Ge Substrates: Final Technical Report, 15 September 2004--30 September 2006

    SciTech Connect (OSTI)

    Ringel, S. A.

    2008-11-01

    Goal is to demo realistic path to III-V multijunction concentrator efficiencies > 40% by substrate-engineering combining compositional grading with patterned epitaxy for small-area cells for high concentration.

  8. Inverted Metamorphic Multijunction (IMM) Cell Processing Instructions

    SciTech Connect (OSTI)

    Duda, A.; Ward, S.; Young, M.

    2012-02-01

    This technical report details the processing schedule used to fabricate Inverted Metamorphic Multijunction (IMM) concentrator solar cells at The National Renewable Energy Laboratory (NREL). These devices are used as experimental test structures to support the research at NREL that is focused on increasing the efficiency of photovoltaic power conversion. They are not intended to be devices suitable for deployment in working concentrator systems primarily because of heat sinking issues. The process schedule was developed to be compatible with small sample sizes and to afford relatively rapid turn-around times, in support of research efforts. The report describes the use of electro deposition of gold for both the back and front contacts. Electro-deposition is used because of its rapid turn around time and because it is a benign metallization technique that is seldom responsible for damage to the semiconductors. The layer transfer technique is detailed including the use of a commercially available adhesive and the etching away of the parent gallium arsenide substrate. Photolithography is used to define front contact grids as well as the mesa area of the cell. Finally, the selective wet chemical etchant system is introduced and its use to reveal the back contact is described.

  9. Boosting Accuracy of Testing Multijunction Solar Cells (Fact Sheet), NREL Highlights in Research & Development, NREL (National Renewable Energy Laboratory)

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

    has developed a more precise technology for measuring efficiency of concentrating solar cells, enabling the industry to advance. Solar researchers have long been unable to reduce an error that occurs during efficiency measurements of triple-absorber, concentrating photovoltaic (CPV) cells- one that is caused by too much spectral irradiance from unfiltered, pulsed xenon solar simulators entering into the bottom subcell during testing. This condition causes an artificial increase in the measured

  10. 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.

  11. Performance of CPV System Using Three Types of III-V Multi-Junction Solar Cells: Preprint

    SciTech Connect (OSTI)

    Hashimoto, J.; Kurtz, S.; Sakurai, K.; Muller, M.; Otani, K.

    2012-04-01

    The performance of sister CPV systems is compared in Japan and the U.S. The conclusion is that the alignment of the systems can affect the design of the solar cells.

  12. Quantum well multijunction photovoltaic cell

    DOE Patents [OSTI]

    Chaffin, R.J.; Osbourn, G.C.

    1983-07-08

    A monolithic, quantum well, multilayer photovoltaic cell comprises a p-n junction comprising a p-region on one side and an n-region on the other side, each of which regions comprises a series of at least three semiconductor layers, all p-type in the p-region and all n-type in the n-region; each of said series of layers comprising alternating barrier and quantum well layers, each barrier layer comprising a semiconductor material having a first bandgap and each quantum well layer comprising a semiconductor material having a second bandgap when in bulk thickness which is narrower than said first bandgap, the barrier layers sandwiching each quantum well layer and each quantum well layer being sufficiently thin that the width of its bandgap is between said first and second bandgaps, such that radiation incident on said cell and above an energy determined by the bandgap of the quantum well layers will be absorbed and will produce an electrical potential across said junction.

  13. Quantum well multijunction photovoltaic cell

    DOE Patents [OSTI]

    Chaffin, Roger J.; Osbourn, Gordon C.

    1987-01-01

    A monolithic, quantum well, multilayer photovoltaic cell comprises a p-n junction comprising a p-region on one side and an n-region on the other side, each of which regions comprises a series of at least three semiconductor layers, all p-type in the p-region and all n-type in the n-region; each of said series of layers comprising alternating barrier and quantum well layers, each barrier layer comprising a semiconductor material having a first bandgap and each quantum well layer comprising a semiconductor material having a second bandgap when in bulk thickness which is narrower than said first bandgap, the barrier layers sandwiching each quantum well layer and each quantum well layer being sufficiently thin that the width of its bandgap is between said first and second bandgaps, such that radiation incident on said cell and above an energy determined by the bandgap of the quantum well layers will be absorbed and will produce an electrical potential across said junction.

  14. NREL: Photovoltaics Research - III-V Multijunction Materials and Devices

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

    R&D III-V Multijunction Materials and Devices R&D NREL has a strong research capability in III-V multijunction photovoltaic (PV) cells. The inverted metamorphic multijunction (IMM) technology, which is fundamentally a new technology path with breakthrough performance and cost advantages, is a particular focus. We invented and first demonstrated the IMM solar cell and introduced it to the PV industry. Our scientists earlier invented and demonstrated the first-ever multijunction PV

  15. Advances in amorphous silicon alloy-based multijunction cells and modules

    SciTech Connect (OSTI)

    Guha, S.; Yang, J.; Banerjee, A.; Glatfelter, T.; Xu, X. )

    1992-12-01

    Multijunction amorphous silicon alloy-based solar cells and modules offer the potential of obtaining high efficiency with long-term stability against light-induced degradation. We have studied the stability of the component cells of the multijunction devices prepared under different deposition conditions. We observe a definite correlation between the microstructure of the intrinsic material and initial and light-degraded performance of the cells. Using suitable deposition conditions and optimum matching of the component cells, we have fabricated double-junction dual-bandgap cells which show stabilized active-area efficiency of 11% after 600 hours of one-sun illumination at 50 [degree]C. Double-junction and triple-junction modules of 900 cm[sup 2] area have been fabricated, and the performance of these panels will be discussed.

  16. PROJECT PROFILE: Stable Perovskite Solar Cells via Chemical Vapor...

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

    Stable Perovskite Solar Cells via Chemical Vapor Deposition PROJECT PROFILE: Stable ... would be suitable for a photovoltaic absorber in a single or multi-junction cell. ...

  17. Commercialization of New Lattice-Matched Multi-Junction Solar Cells Based on Dilute Nitrides: July 8, 2010 - March 7, 2012

    SciTech Connect (OSTI)

    Herb, J.

    2012-04-01

    Final Technical Progress Report for PV Incubator subcontract NAT-0-99013-03. The overall objective of this Incubator subcontract was to complete the work necessary to make commercial ready solar cells using the dilute nitride technology. The specific objectives of this program were aimed at completing the development of a triple-junction solar cell that incorporates a GaInNAs {approx}1eV subcell to the point of commercial readiness, and determining the cell reliability and, if necessary, identifying and eliminating process or material related issues that lead to early-life cell failures. There were three major objectives for Phase 1, each of which focuses on a key element of the solar cell that determines its performance in a commercial CPV system. One objective was to optimize the quality and performance of the key individual components making up the solar cell structure and then to optimize the integration of these components into a complete triple-junction cell. A second objective was to design and test anti-reflective coating that maximizes the light coupled into a 3J cell with a {approx}1 eV bottom cell bandgap. The third objective was to develop Highly Accelerated Life Tests (HALT) protocols and tools for identifying and correcting potential reliability problems. The Phase 2 objectives were a continuation of the work begun in Phase 1 but aimed at optimizing cell performance for commercial requirements. Phase 2 had four primary objectives: (1) develop a glass-matched anti-reflective coating (ARC) and optimize the cell/ARC to give good performance at 60C operating temperature, (2) optimize the cell for good operation at 60C and high concentration, and (3) complete the light biased HALT system and use it to determine what, if any, failures are observed, and (4) determine the reliability limits of the optimized cell.

  18. Stable a-Si:H-Based Multijunction Solar Cells with Guidance from Real-Time Optics: Final Report, 17 July 1998--16 November 2001

    SciTech Connect (OSTI)

    Wronski, C. R.; Collins, R. W.; Pearce, J. M.; Koval, R. J.; Ferlauto, A. S.; Ferreira, G. M.; Chen C.

    2002-08-01

    This report describes the new insights obtained into the growth of hydrogenated silicon (Si:H) films via real-time spectroscopic ellipsometry (RTSE) measurements. Evolutionary phase diagrams were expanded to include the effects of different deposition conditions, including rf power, pressure, and temperature. Detailed studies of degradation kinetics in thin films and corresponding solar cells have been carried out. Both p-i-n and n-i-p solar cells that incorporate Si:H i-layers deposited with and without H2-dilution have been studied. For the first time, direct and reliable correlations have been obtained between the light-induced changes in thin-film materials and the degradation of the corresponding solar cells.

  19. Optimization of Phase-Engineered a-Si:H-Based Multi-Junction Solar Cells: Final Technical Report, October 2001-July 2005

    SciTech Connect (OSTI)

    Wronski, C. R.; Collins, R. W.; Podraza, N. J.; Vlahos, V.; Pearce, J. M.; Deng, J.; Albert, M.; Ferreira, G. M.; Chen, C.

    2006-08-01

    The scope of the work under this subcontract has involved investigating engineered improvements in the performance and stability of solar cells in a systematic way, which included the following four tasks: (1) Materials research and device development; (2) Process improvement directed by real time diagnostics; (3) Device loss mechanisms; and (4) Characterization strategies for advanced materials Our work has resulted in new and important insights into the deposition of a-Si:H-based materials, as well as into the nature of the Staebler-Wronski Effect (SWE). Presumably, many of these insights will be used by industrial partners to develop more systematic approaches in optimizing solar cells for higher performance and stability. This effort also cleared up several serious misconceptions about the nature of the p-layer in cells and the SWE in materials and cells. Finally, the subcontract identified future directions that should be pursued for greater understanding and improvement.

  20. Multijunction III-V Photovoltaics Research

    Broader source: Energy.gov [DOE]

    DOE invests in multijunction III-V solar cell research to drive down the costs of the materials, manufacturing, tracking techniques, and concentration methods used with this technology. Below is a...

  1. Final Report- Low Cost, Epitaxial Growth of II-VI Materials for Multijunction Photovoltaic Cells

    Office of Energy Efficiency and Renewable Energy (EERE)

    Multijunction solar cells have theoretical power conversion efficiencies in excess of 29% under one sun illumination and could become a highly disruptive technology if fabricated using low cost processing techniques to epitaxially grow defect tolerant, thin films on silicon. The PLANT PV/Molecular Foundry team studied the feasibility of using cadmium selenide (CdSe) as the wide band-gap, top cell and Si as the bottom cell in monolithically integrated tandem architecture. The greatest challenge in developing tandem solar cells is depositing wide band gap semiconductors that are both highly doped and have minority carrier lifetimes greater than 1 ns. The proposed research was to determine whether it is possible to rapidly grow CdSe films with sufficient minority carrier lifetimes and doping levels required to produce an open-circuit voltage (Voc) greater than 1.1V using close-space sublimation (CSS).

  2. GaAs, AlGaAs and InGaP Tunnel Junctions for Multi-Junction Solar Cells Under Concentration: Resistance Study

    SciTech Connect (OSTI)

    Wheeldon, Jeffrey F.; Valdivia, Christopher E.; Walker, Alex; Kolhatkar, Gitanja; Hall, Trevor J.; Hinzer, Karin; Masson, Denis; Riel, Bruno; Fafard, Simon; Jaouad, Abdelatif; Turala, Artur; Ares, Richard; Aimez, Vincent

    2010-10-14

    The following four TJ designs, AlGaAs/AlGaAs, GaAs/GaAs, AlGaAs/InGaP and AlGaAs/GaAs are studied to determine minimum doping concentration to achieve a resistance of <10{sup -4} {omega}{center_dot}cm{sup 2} and a peak tunneling current suitable for MJ solar cells up to 1500-suns concentration (operating current of 21 A/cm{sup 2}). Experimentally calibrated numerical models are used to determine how the resistance changes as a function of doping concentration. The AlGaAs/GaAs TJ design is determined to require the least doping concentration to achieve the specified resistance and peak tunneling current, followed by the GaAs/GaAs, and AlGaAs/AlGaAs TJ designs. The AlGaAs/InGaP TJ design can only achieve resistances >5x10{sup -4} {omega}cm{sup 2}.

  3. 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.

  4. Electric characteristics of germanium Vertical Multijunction (VMJ) photovoltaic cells under high intensity illumination

    SciTech Connect (OSTI)

    Unishkov, V.A.

    1997-03-01

    This paper presents the results of the performance evaluation of Vertical Multijunction (VMJ) germanium (Ge) photovoltaic (PV) cells. Vertical Multijunction Germanium Photovoltaic cells offer several advantages for Thermophotovoltaic (TPV) applications such as high intensity light conversion, low series resistance, more efficient coupling to lower temperature sources, high output voltage, simplified heat rejection system as well as potentially simple fabrication technology and low cost photovoltaic converter device. {copyright} {ital 1997 American Institute of Physics.}

  5. Deep-level defects introduced by 1 MeV electron radiation in AlInGaP for multijunction space solar cells

    SciTech Connect (OSTI)

    Lee, H.S.; Yamaguchi, M.; Ekins-Daukes, N. J.; Khan, A.; Takamoto, T.; Agui, T.; Kamimura, K.; Kaneiwa, M.; Imaizumi, M.; Ohshima, T.; Itoh, H.

    2005-11-01

    Presented in this paper are 1 MeV electron irradiation effects on wide-band-gap (1.97 eV) (Al{sub 0.08}Ga{sub 0.92}){sub 0.52}In{sub 0.48}P diodes and solar cells. The carrier removal rate estimated in p-AlInGaP with electron fluence is about 1 cm{sup -1}, which is lower than that in InP and GaAs. From high-temperature deep-level transient spectroscopy measurements, a deep-level defect center such as majority-carrier (hole) trap H2 (E{sub {nu}}+0.90{+-}0.05 eV) was observed. The changes in carrier concentrations ({delta}p) and trap densities as a function of electron fluence were compared, and as a result the total introduction rate, 0.39 cm{sup -1}, of majority-carrier trap centers (H1 and H2) is different from the carrier removal rate, 1 cm{sup -1}, in p-AlInGaP. From the minority-carrier injection annealing (100 mA/cm{sup 2}), the annealing activation energy of H2 defect is {delta}E=0.60 eV, which is likely to be associated with a vacancy-phosphorus Frenkel pair (V{sub p}-P{sub i}). The recovery of defect concentration and carrier concentration in the irradiated p-AlInGaP by injection relates that a deep-level defect H2 acts as a recombination center as well as compensator center.

  6. Bandgap Engineering in High-Efficiency Multijunction Concentrator Cells

    SciTech Connect (OSTI)

    King, R. R.; Sherif, R. A.; Kinsey, G. S.; Kurtz, S.; Fetzer, C. M.; Edmondson, K. M.; Law, D. C.; Cotal, H. L.; Krut, D. D.; Ermer, J. H.; Karam, N. H.

    2005-08-01

    This paper discusses semiconductor device research paths under investigation with the aim of reaching the milestone efficiency of 40%. A cost analysis shows that achieving very high cell efficiencies is crucial for the realization of cost-effective photovoltaics, because of the strongly leveraging effect of efficiency on module packaging and balance-of systems costs. Lattice-matched (LM) GaInP/ GaInAs/ Ge 3-junction cells have achieved the highest independently confirmed efficiency at 175 suns, 25?C, of 37.3% under the standard AM1.5D, low-AOD terrestrial spectrum. Lattice-mismatched, or metamorphic (MM), materials offer still higher potential efficiencies, if the crystal quality can be maintained. Theoretical efficiencies well over 50% are possible for a MM GaInP/ 1.17-eV GaInAs/ Ge 3-junction cell limited by radiative recombination at 500 suns. The bandgap - open circuit voltage offset, (Eg/q) - Voc, is used as a valuable theoretical and experimental tool to characterize multijunction cells with subcell bandgaps ranging from 0.7 to 2.1 eV. Experimental results are presented for prototype 6-junction cells employing an active {approx}1.1-eV dilute nitride GaInNAs subcell, with active-area efficiency greater than 23% and over 5.3 V open-circuit voltage under the 1-sun AM0 space spectrum. Such cell designs have theoretical efficiencies under the terrestrial spectrum at 500 suns concentration exceeding 55% efficiency, even for lattice-matched designs.

  7. Process for mounting a protection diode on a vertical multijunction photovoltaic cell structure and photovoltaic cells obtained

    SciTech Connect (OSTI)

    Arnould, J.

    1982-09-07

    In a stack of diodes forming a vertical multijunction photovoltaic cell, an inversely connected diode is firmly secured to this stack with possible insertion of a intermediate wafer made from a conducting material.

  8. Broad spectrum solar cell

    DOE Patents [OSTI]

    Walukiewicz, Wladyslaw; Yu, Kin Man; Wu, Junqiao; Schaff, William J.

    2007-05-15

    An alloy having a large band gap range is used in a multijunction solar cell to enhance utilization of the solar energy spectrum. In one embodiment, the alloy is In.sub.1-xGa.sub.xN having an energy bandgap range of approximately 0.7 eV to 3.4 eV, providing a good match to the solar energy spectrum. Multiple junctions having different bandgaps are stacked to form a solar cell. Each junction may have different bandgaps (realized by varying the alloy composition), and therefore be responsive to different parts of the spectrum. The junctions are stacked in such a manner that some bands of light pass through upper junctions to lower junctions that are responsive to such bands.

  9. Current and lattice matched tandem solar cell

    DOE Patents [OSTI]

    Olson, Jerry M.

    1987-01-01

    A multijunction (cascade) tandem photovoltaic solar cell device is fabricated of a Ga.sub.x In.sub.1-x P (0.505.ltoreq.X.ltoreq.0.515) top cell semiconductor lattice matched to a GaAs bottom cell semiconductor at a low-resistance heterojunction, preferably a p+/n+ heterojunction between the cells. The top and bottom cells are both lattice matched and current matched for high efficiency solar radiation conversion to electrical energy.

  10. High-Efficiency Multijunction Photovoltaics | Center for Energy Efficient

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

    Materials Efficiency Multijunction Photovoltaics This Task Group focuses on novel approaches to InGaN and multijunction photovoltaics for unprecedented high photovoltaic energy conversion efficiencies. This goal requires development of new techniques for the efficient simultaneous coupling of electrons and photons through the various junctions. Figure 1 shows a device architecture that is one of the goals of the project: a five-junction (5J) solar cell using a high-bandgap InGaN top junction

  11. TJ Solar Cell

    SciTech Connect (OSTI)

    Friedman, Daniel

    2009-04-17

    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.

  12. NREL Solar Cell Wins Federal Technology Transfer Prize - News Releases |

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

    NREL Solar Cell Wins Federal Technology Transfer Prize May 7, 2009 A new class of ultra-light, high-efficiency solar cells developed by the U.S. Department of Energy's National Renewable Energy Laboratory has been awarded a national prize for the commercialization of federally funded research. The Inverted Metamorphic Multijunction (IMM) Solar Cell was named a winner of the 2009 Award for Excellence in Technology Transfer by the Federal Laboratory Consortium for Technology Transfer. The

  13. Multijunction Photovoltaic Technologies for High-Performance Concentrators

    SciTech Connect (OSTI)

    McConnell, R.; Symko-Davies, M.

    2006-01-01

    Multijunction solar cells provide high-performance technology pathways leading to potentially low-cost electricity generated from concentrated sunlight. The National Center for Photovoltaics at the National Renewable Energy Laboratory has funded different III-V multijunction solar cell technologies and various solar concentration approaches. Within this group of projects, III-V solar cell efficiencies of 41% are close at hand and will likely be reported in these conference proceedings. Companies with well-developed solar concentrator structures foresee installed system costs of $3/watt--half of today's costs--within the next 2 to 5 years as these high-efficiency photovoltaic technologies are incorporated into their concentrator photovoltaic systems. These technology improvements are timely as new large-scale multi-megawatt markets, appropriate for high performance PV concentrators, open around the world.

  14. Multijunction Photovoltaic Technologies for High-Performance Concentrators: Preprint

    SciTech Connect (OSTI)

    McConnell, R.; Symko-Davies, M.

    2006-05-01

    Multijunction solar cells provide high-performance technology pathways leading to potentially low-cost electricity generated from concentrated sunlight. The National Center for Photovoltaics at the National Renewable Energy Laboratory has funded different III-V multijunction solar cell technologies and various solar concentration approaches. Within this group of projects, III-V solar cell efficiencies of 41% are close at hand and will likely be reported in these conference proceedings. Companies with well-developed solar concentrator structures foresee installed system costs of $3/watt--half of today's costs--within the next 2 to 5 years as these high-efficiency photovoltaic technologies are incorporated into their concentrator photovoltaic systems. These technology improvements are timely as new large-scale multi-megawatt markets, appropriate for high performance PV concentrators, open around the world.

  15. Ultra-High-Efficiency Multijunction Cell and Receiver Module, Phase 1B: High Performance PV Exploring and Accelerating Ultimate Pathways; Final Subcontract Report, 13 May 2005 - 10 December 2008

    SciTech Connect (OSTI)

    King, R. R.

    2010-03-01

    Spectrolab's two High Performance Photovoltaics primary objectives: (1) develop ultra-high-efficiency concentrator multijunction cells and (2) develop a robust concentrator cell receiver package.

  16. Daily Fill Factor Variation as a Diagnostic Probe of Multijunction Concentrator Systems During Outdoor Operation

    SciTech Connect (OSTI)

    McMahon, W. E.; Emery, K. E.; Friedman, D. J.; Ottoson, L.; Young, M. S.; Ward, J. S.; Kramer, C. M.; Duda, A.; Kurtz, S.

    2007-01-01

    The work presented here is for GaInP2/GaAs tandem cells, but the conclusions are equally valid for GaInP2/GaAs/Ge triple-junction cells. Optimizing a concentrator system which uses multijunction solar cells is challenging because: (a) the conditions are variable, so the solar cells rarely operate under optimal conditions and (b) the conditions are not controlled, so any design problems are difficult to characterize. Any change in the spectral content of direct-beam sunlight as it passes through the concentrator optics is of particular interest, as it can reduce the performance of multijunction cells and is difficult to characterize.

  17. Producing Solar Cells By Surface Preparation For Accelerated Nucleation Of Microcrystalline Silicon On Heterogeneous Substrates.

    DOE Patents [OSTI]

    Yang, Liyou; Chen, Liangfan

    1998-03-24

    Attractive multi-junction solar cells and single junction solar cells with excellent conversion efficiency can be produced with a microcrystalline tunnel junction, microcrystalline recombination junction or one or more microcrystalline doped layers by special plasma deposition processes which includes plasma etching with only hydrogen or other specified etchants to enhance microcrystalline growth followed by microcrystalline. nucleation with a doped hydrogen-diluted feedstock.

  18. 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.

  19. NREL Demonstrates 45.7% Efficiency for Concentrator Solar Cell - News

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

    Releases | NREL NREL Demonstrates 45.7% Efficiency for Concentrator Solar Cell New design for ultra-efficient III-V multijunction cell pushes the limits of solar conversion December 16, 2014 The Energy Department's National Renewable Energy Laboratory has announced the demonstration of a 45.7 percent conversion efficiency for a four-junction solar cell at 234 suns concentration. This achievement represents one of the highest photovoltaic research cell efficiencies achieved across all types

  20. Current- and lattice-matched tandem solar cell

    DOE Patents [OSTI]

    Olson, J.M.

    1985-10-21

    A multijunction (cascade) tandem photovoltaic solar cell device is fabricated of a Ga/sub x/In/sub 1-x/P (0.505 equal to or less than x equal to or less than 0.515) top cell semiconductor lattice-matched to a GaAs bottom cell semiconductor at a low resistance heterojunction, preferably a p/sup +//n/sup +/ heterojunction between the cells. The top and bottom cells are both lattice-matched and current-matched for high efficiency solar radiation conversion to electrical energy.

  1. Current flow and efficiencies of concentrator InGaP/GaAs/Ge solar cells at temperatures below 300K

    SciTech Connect (OSTI)

    Kalinovsky, Vitaly S. Kontrosh, Evgeny V. Dmitriev, Pavel A. Pokrovsky, Pavel V. Chekalin, Alexander V. Andreev, Viacheslav M.

    2014-09-26

    The forward dark current density voltage (J-V) characteristic is one of the most important characteristics of multi-junction solar cells. It indicates that the mechanisms of current flow in the space charge region of photoactive p-n junctions. If one is to idealize the optical and electrical (coupling) elements of the solar cells, it is the J-V characteristic that determines the theoretically possible efficiency of the solar cell. In this paper, using the connection between the dark J-V and photovoltaic (?-J{sub g}) efficiency generated current density characteristics, the effect of current transport mechanisms in the space charge on the efficiency of multi-junction solar cells was investigated in the temperature range of 300 80 K. In the experimental J-V and ?-J{sub g} curves of the multi-junction solar cells, segments corresponding to the dominant current transport mechanisms were identified. The developed method, based on the analysis of forward dark J-V characteristics, makes it possible to identify the parameters affecting the efficiency of the multi-junction solar cells in a wide range of temperatures and solar radiation concentration.

  2. Optimal Materials and Deposition Technique Lead to Cost-Effective Solar Cell with Best-Ever Conversion Efficiency (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2012-07-01

    This fact sheet describes how the SJ3 solar cell was invented, explains how the technology works, and why it won an R&D 100 Award. Based on NREL and Solar Junction technology, the commercial SJ3 concentrator solar cell - with 43.5% conversion efficiency at 418 suns - uses a lattice-matched multijunction architecture that has near-term potential for cells with {approx}50% efficiency. Multijunction solar cells have higher conversion efficiencies than any other type of solar cell. But developers of utility-scale and space applications crave even better efficiencies at lower costs to be both cost-effective and able to meet the demand for power. The SJ3 multijunction cell, developed by Solar Junction with assistance from foundational technological advances by the National Renewable Energy Laboratory, has the highest efficiency to date - almost 2% absolute more than the current industry standard multijunction cell-yet at a comparable cost. So what did it take to create this cell having 43.5% efficiency at 418-sun concentration? A combination of materials with carefully designed properties, a manufacturing technique allowing precise control, and an optimized device design.

  3. 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.

  4. PV Optics: A Software Package for Solar Cells and Module Design

    SciTech Connect (OSTI)

    Sopori, B.

    2007-01-01

    PV Optics is a user-friendly software package developed to design and analyze solar cells and modules. It is applicable to a variety of optical structures, including thin and thick cells with light-trapping structures and metal optics. Using a combination of wave and ray optics to include effects of coherence and interference, it can be used to design single-junction and multijunction solar cells and modules. This paper describes some basic applications of PV Optics for crystalline and amorphous Si solar cell design. We present examples to examine the effects on solar cell performance of wafer thickness, antireflection coating thickness, texture height, and metal loss.

  5. Inverted Metamorphic Cell Development: Cooperative Research and Development Final Report, CRADA Number CRD-05-156

    SciTech Connect (OSTI)

    Wanlass, M.

    2012-05-01

    This CRADA targeted technology transfer of the inverted metamorphic multi-junction (IMM) solar cell innovation from NREL to Emcore Photovoltaics. The technology transfer was successfully completed. Additionally, NREL provided materials characterization of solar cell structures produced at Emcore.

  6. High efficiency solar cells combining a perovskite and a silicon heterojunction solar cells via an optical splitting system

    SciTech Connect (OSTI)

    Uzu, Hisashi E-mail: npark@skku.edu; Ichikawa, Mitsuru; Hino, Masashi; Nakano, Kunihiro; Meguro, Tomomi; Yamamoto, Kenji; Hernández, José Luis; Kim, Hui-Seon; Park, Nam-Gyu E-mail: npark@skku.edu

    2015-01-05

    We have applied an optical splitting system in order to achieve very high conversion efficiency for a full spectrum multi-junction solar cell. This system consists of multiple solar cells with different band gap optically coupled via an “optical splitter.” An optical splitter is a multi-layered beam splitter with very high reflection in the shorter-wave-length range and very high transmission in the longer-wave-length range. By splitting the incident solar spectrum and distributing it to each solar cell, the solar energy can be managed more efficiently. We have fabricated optical splitters and used them with a wide-gap amorphous silicon (a-Si) solar cell or a CH{sub 3}NH{sub 3}PbI{sub 3} perovskite solar cell as top cells, combined with mono-crystalline silicon heterojunction (HJ) solar cells as bottom cells. We have achieved with a 550 nm cutoff splitter an active area conversion efficiency of over 25% using a-Si and HJ solar cells and 28% using perovskite and HJ solar cells.

  7. High Performance Photovoltaic Solar Cells: Cooperative Research and Development Final Report, CRADA Number CRD-05-169

    SciTech Connect (OSTI)

    Steiner, M.

    2012-07-01

    NREL will provide certified measurements of the conversion efficiency at high concentration for several multijunction solar cells that were fabricated by Cyrium Technologies. In an earlier phase of the CRADA, Cyrium provided epitaxially-grown material and NREL processed the samples into devices and measured the performance.

  8. 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).

  9. GaNPAs Solar Cells Lattice-Matched To GaP: Preprint

    SciTech Connect (OSTI)

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

    2002-05-01

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

  10. Performance and Reliability of Multijunction III-V Modules for Concentrator Dish and Central Receiver Applications

    SciTech Connect (OSTI)

    Verlinden, P. J.; Lewandowski, A.; Bingham, C.; Kinsey, G. S.; Sherif, R. A.; Laisch, J. B.

    2006-01-01

    Over the last 15 years, Solar Systems have developed a dense array receiver PV technology for 500X concentrator reflective dish applications. This concentrator PV technology has been successfully deployed at six different locations in Australia, counting for more than 1 MWp of installed peak power. A new Multijunction III-V receiver to replace the current silicon Point-Contact solar cells has recently been developed. The new receiver technology is based on high-efficiency (>32%) Concentrator Ultra Triple Junction (CUTJ) solar cells from Spectrolab, resulting in system power and energy performance improvement of more than 50% compared to the silicon cells. The 0.235 m{sup 2} concentrator PV receiver, designed for continuous 500X operation, is composed of 64 dense array modules, and made of series and parallel-connected solar cells, totaling approximately 1,500 cells. The individual dense array modules have been tested under high intensity pulsed light, as well as with concentrated sunlight at the Solar Systems research facility and at the National Renewable Energy Laboratory's High Flux Solar Furnace. The efficiency of the dense array modules ranges from 30% to 36% at 500X (50 W/cm{sup 2}, AM1.5D low AOD, 21C). The temperature coefficients for power, voltage and current, as well as the influence of Air Mass on the cell responsivity, were measured. The reliability of the dense array multijunction III-V modules has been studied with accelerated aging tests, such as thermal cycling, damp heat and high-temperature soak, and with real-life high-intensity exposure. The first 33 kWp multijunction III-V receiver was recently installed in a Solar Systems dish and tested in real-life 500X concentrated sunlight conditions. Receiver efficiencies of 30.3% and 29.0% were measured at Standard Operating Conditions and Normal Operating Conditions respectively.

  11. Silicon solar cell assembly

    DOE Patents [OSTI]

    Burgess, Edward L.; Nasby, Robert D.; Schueler, Donald G.

    1979-01-01

    A silicon solar cell assembly comprising a large, thin silicon solar cell bonded to a metal mount for use when there exists a mismatch in the thermal expansivities of the device and the mount.

  12. 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.

  13. Lattice-Mismatched GaAs/InGaAs Two-Junction Solar Cells by Direct Wafer Bonding

    SciTech Connect (OSTI)

    Tanabe, K.; Aiken, D. J.; Wanlass, M. W.; Morral, A. F.; Atwater, H. A.

    2006-01-01

    Direct bonded interconnect between subcells of a lattice-mismatched III-V compound multijunction cell would enable dislocation-free active regions by confining the defect network needed for lattice mismatch accommodation to tunnel junction interfaces, while metamorphic growth inevitably results in less design flexibility and lower material quality than is desirable. The first direct-bond interconnected multijunction solar cell, a two-terminal monolithic GaAs/InGaAs two-junction solar cell, is reported and demonstrates viability of direct wafer bonding for solar cell applications. The tandem cell open-circuit voltage was approximately the sum of the subcell open-circuit voltages. This achievement shows direct bonding enables us to construct lattice-mismatched III-V multijunction solar cells and is extensible to an ultrahigh efficiency InGaP/GaAs/InGaAsP/InGaAs four-junction cell by bonding a GaAs-based lattice-matched InGaP/GaAs subcell and an InP-based lattice-matched InGaAsP/InGaAs subcell. The interfacial resistance experimentally obtained for bonded GaAs/InP smaller than 0.10 Ohm-cm{sup 2} would result in a negligible decrease in overall cell efficiency of {approx}0.02%, under 1-sun illumination.

  14. Advanced materials development for multi-junction monolithic photovoltaic devices

    SciTech Connect (OSTI)

    Dawson, L.R.; Reno, J.L.

    1996-07-01

    We report results in three areas of research relevant to the fabrication of monolithic multi-junction photovoltaic devices. (1) The use of compliant intervening layers grown between highly mismatched materials, GaAs and GaP (same lattice constant as Si), is shown to increase the structural quality of the GaAs overgrowth. (2) The use of digital alloys applied to the MBE growth of GaAs{sub x}Sb{sub l-x} (a candidate material for a two junction solar cell) provides increased control of the alloy composition without degrading the optical properties. (3) A nitrogen plasma discharge is shown to be an excellent p-type doping source for CdTe and ZnTe, both of which are candidate materials for a two junction solar cell.

  15. NREL Solar Technologies Recognized with Special R&D 100 Honors...

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

    called the Inverted Metamorphic Multi-Junction solar cell, and a process that uses ink-jet printing to manufacture thin-film photovoltaics were selected for Editor's Choice Awards. ...

  16. Final Report- Technology Enabling Ultra High Concentration Multi-Junction Cells

    Broader source: Energy.gov [DOE]

    Awardee: North Carolina State UniversityLocation: Raleigh, NCSubprogram: PhotovoltaicsFunding Program: Foundational Program to Advance Cell Efficiency (F-PACE) ​Principal Investigator: S. M. Bedair

  17. Light-splitting photovoltaic system utilizing two dual-junction solar cells

    SciTech Connect (OSTI)

    Xiong, Kanglin; Yang, Hui; Lu, Shulong; Dong, Jianrong; Zhou, Taofei; Wang, Rongxin; Jiang, Desheng

    2010-12-15

    There are many difficulties limiting the further development of monolithic multi-junction solar cells, such as the growth of lattice-mismatched material and the current matching constraint. As an alternative approach, the light-splitting photovoltaic system is investigated intensively in different aspects, including the energy loss mechanism and the choice of energy bandgaps of solar cells. Based on the investigation, a two-dual junction system has been implemented employing lattice-matched GaInP/GaAs and InGaAsP/InGaAs cells grown epitaxially on GaAs and InP substrates, respectively. (author)

  18. Raising the Efficiency Ceiling with Multijunction III-V Concentrator Photovoltaics

    SciTech Connect (OSTI)

    King, R. R.; Boca, A.; Edmondson, K. M.; Romero, M. J.; Yoon, H.; Law, D. C.; Fetzer, C. M.; Haddad, M.; Zakaria, A.; Hong, W.; Mesropian, S.; Krut, D. D.; Kinsey, G. S.; Pien, R.; Sherif, R. A.; Karam, N. H.

    2008-01-01

    In this paper, we look at the question 'how high can solar cell efficiency go?' from both theoretical and experimental perspectives. First-principle efficiency limits are analyzed for some of the main candidates for high-efficiency multijunction terrestrial concentrator cells. Many of these cell designs use lattice-mismatched, or metamorphic semiconductor materials in order to tune subcell band gaps to the solar spectrum. Minority-carrier recombination at dislocations is characterized in GaInAs inverted metamorphic solar cells, with band gap ranging from 1.4 to 0.84 eV, by light I-V, electron-beam-induced current (EBIC), and cathodoluminescence (CL). Metamorphic solar cells with a 3-junction GaInP/ GaInAs/ Ge structure were the first cells to reach over 40% efficiency, with an independently confirmed efficiency of 40.7% (AM1.5D, low-AOD, 240 suns, 25 C). The high efficiency of present III-V multijunction cells now in high-volume production, and still higher efficiencies of next-generation cells, is strongly leveraging for low-cost terrestrial concentrator PV systems.

  19. Photovoltaic solar cell

    SciTech Connect (OSTI)

    Nielson, Gregory N.; Gupta, Vipin P.; Okandan, Murat; Watts, Michael R.

    2015-09-08

    A photovoltaic solar concentrator is disclosed with one or more transverse-junction solar cells (also termed point contact solar cells) and a lens located above each solar cell to concentrate sunlight onto the solar cell to generate electricity. Piezoelectric actuators tilt or translate each lens to track the sun using a feedback-control circuit which senses the electricity generated by one or more of the solar cells. The piezoelectric actuators can be coupled through a displacement-multiplier linkage to provide an increased range of movement of each lens. Each lens in the solar concentrator can be supported on a frame (also termed a tilt plate) having three legs, with the movement of the legs being controlled by the piezoelectric actuators.

  20. Heterojunction solar cell

    DOE Patents [OSTI]

    Olson, J.M.

    1994-08-30

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

  1. Heterojunction solar cell

    DOE Patents [OSTI]

    Olson, Jerry M.

    1994-01-01

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

  2. Bifacial solar cell with SnS absorber by vapor transport deposition

    SciTech Connect (OSTI)

    Wangperawong, Artit; Hsu, Po-Chun; Yee, Yesheng; Herron, Steven M.; Clemens, Bruce M.; Cui, Yi; Bent, Stacey F.

    2014-10-27

    The SnS absorber layer in solar cell devices was produced by vapor transport deposition (VTD), which is a low-cost manufacturing method for solar modules. The performance of solar cells consisting of Si/Mo/SnS/ZnO/indium tin oxide (ITO) was limited by the SnS layer's surface texture and field-dependent carrier collection. For improved performance, a fluorine doped tin oxide (FTO) substrate was used in place of the Mo to smooth the topography of the VTD SnS and to make bifacial solar cells, which are potentially useful for multijunction applications. A bifacial SnS solar cell consisting of glass/FTO/SnS/CdS/ZnO/ITO demonstrated front- and back-side power conversion efficiencies of 1.2% and 0.2%, respectively.

  3. NREL Measures IMM Solar Cell Performance for CPV (Fact Sheet), NREL Highlights, Science

    SciTech Connect (OSTI)

    Not Available

    2011-09-01

    New measurement capability supports the development of high-efficiency solar cells for concentrating photovoltaic (CPV) application. NREL scientists recently completed a set of measurements on the performance of an inverted metamorphic multijunction (IMM) solar cell as a function of concentration and cell operating temperature. The triple-junction cell had subcell bandgaps of 1.81, 1.40, and 1.00. Much of the work focused on developing and validating the measurement techniques (i.e., the spectral response of the three subcells was measured at five temperatures, and those data were used to properly adjust the solar simulators at each temperature). Multijunction concentrator solar cells are typically evaluated under flash illumination at 25 C, but this condition significantly underestimates the thermal load on the cell in an actual real-world module, where the steady-state concentrated illumination can raise the operating temperature to as high as 100 C. The NREL-developed measurement technique addresses this issue. This work demonstrated that the IMM cell has better temperature coefficients than its traditional upright, germanium-based, lattice-matched counterpart and will thus perform better in actual CPV applications. This new measurement capability will support NREL's development of IMM cells that are optimally designed for operation at temperatures relevant to actual systems operation.

  4. Innotech Solar AS formerly known as Solar Cell Repower | Open...

    Open Energy Info (EERE)

    Innotech Solar AS formerly known as Solar Cell Repower Jump to: navigation, search Name: Innotech Solar AS (formerly known as Solar Cell Repower) Place: Narvik, Norway Zip: 8512...

  5. 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.

  6. 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.

  7. High-efficiency solar cell and method for fabrication

    DOE Patents [OSTI]

    Hou, Hong Q.; Reinhardt, Kitt C.

    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).

  8. Stable, high-efficiency amorphous silicon solar cells with low hydrogen content

    SciTech Connect (OSTI)

    Fortmann, C.M.; Hegedus, S.S. )

    1992-12-01

    Results and conclusions obtained during a research program of the investigation of amorphous silicon and amorphous silicon based alloy materials and solar cells fabricated by photo-chemical vapor and glow discharge depositions are reported. Investigation of the effects of the hydrogen content in a-si:H i-layers in amorphous silicon solar cells show that cells with lowered hydrogen content i-layers are more stable. A classical thermodynamic formulation of the Staebler-Wronski effect has been developed for standard solar cell operating temperatures and illuminations. Methods have been developed to extract a lumped equivalent circuit from the current voltage characteristic of a single junction solar cell in order to predict its behavior in a multijunction device.

  9. Solar Cells | Open Energy Information

    Open Energy Info (EERE)

    Solar Cells Place: Split, Croatia Zip: 21000 Product: manufacturers of PV modules References: Solar Cells1 This article is a stub. You can help OpenEI by expanding it. Solar...

  10. NREL Develops ZnSiP2 for Silicon-Based Tandem Solar Cells (Fact Sheet), NREL Highlights in Research & Development, NREL (National Renewable Energy Laboratory)

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

    Combining an Earth-abundant chalcopyrite with a silicon layer could significantly boost conversion efficiency above that of single-junction silicon solar cells. A current technological challenge in photovoltaics (PV) is to implement a lattice-matched, optically efficient material to be used in conjunction with silicon for tandem PV cells. III-V materials currently hold the world-record conver- sion efficiencies for both single- and multijunction cells. Researchers at the National Renewable

  11. Photovoltaic solar cell

    DOE Patents [OSTI]

    Nielson, Gregory N; Cruz-Campa, Jose Luis; Okandan, Murat; Resnick, Paul J

    2014-05-20

    A photovoltaic solar cell for generating electricity from sunlight is disclosed. The photovoltaic solar cell comprises a plurality of spaced-apart point contact junctions formed in a semiconductor body to receive the sunlight and generate the electricity therefrom, the plurality of spaced-apart point contact junctions having a first plurality of regions having a first doping type and a second plurality of regions having a second doping type. In addition, the photovoltaic solar cell comprises a first electrical contact electrically connected to each of the first plurality of regions and a second electrical contact electrically connected to each of the second plurality of regions, as well as a passivation layer covering major surfaces and sidewalls of the photovoltaic solar cell.

  12. Solar cell array interconnects

    DOE Patents [OSTI]

    Carey, P.G.; Thompson, J.B.; Colella, N.J.; Williams, K.A.

    1995-11-14

    Electrical interconnects are disclosed for solar cells or other electronic components using a silver-silicone paste or a lead-tin (Pb-Sn) no-clean fluxless solder cream, whereby the high breakage of thin (<6 mil thick) solar cells using conventional solder interconnect is eliminated. The interconnects of this invention employs copper strips which are secured to the solar cells by a silver-silicone conductive paste which can be used at room temperature, or by a Pb-Sn solder cream which eliminates undesired residue on the active surfaces of the solar cells. Electrical testing using the interconnects of this invention has shown that no degradation of the interconnects developed under high current testing, while providing a very low contact resistance value. 4 figs.

  13. Photovoltaic solar cell

    DOE Patents [OSTI]

    Nielson, Gregory N; Okandan, Murat; Cruz-Campa, Jose Luis; Resnick, Paul J

    2013-11-26

    A photovoltaic solar cell for generating electricity from sunlight is disclosed. The photovoltaic solar cell comprises a plurality of spaced-apart point contact junctions formed in a semiconductor body to receive the sunlight and generate the electicity therefrom, the plurality of spaced-apart point contact junctions having a first plurality of regions having a first doping type and a second plurality of regions having a second doping type. In addition, the photovoltaic solar cell comprises a first electrical contact electrically connected to each of the first plurality of regions and a second electrical contact electrically connected to each of the second plurality of regions, as well as a passivation layer covering major surfaces and sidewalls of the photovoltaic solar cell.

  14. Solar cell array interconnects

    DOE Patents [OSTI]

    Carey, Paul G.; Thompson, Jesse B.; Colella, Nicolas J.; Williams, Kenneth A.

    1995-01-01

    Electrical interconnects for solar cells or other electronic components using a silver-silicone paste or a lead-tin (Pb-Sn) no-clean fluxless solder cream, whereby the high breakage of thin (<6 mil thick) solar cells using conventional solder interconnect is eliminated. The interconnects of this invention employs copper strips which are secured to the solar cells by a silver-silicone conductive paste which can be used at room temperature, or by a Pb-Sn solder cream which eliminates undesired residue on the active surfaces of the solar cells. Electrical testing using the interconnects of this invention has shown that no degradation of the interconnects developed under high current testing, while providing a very low contact resistance value.

  15. Nanocrystal Solar Cells

    SciTech Connect (OSTI)

    Gur, Ilan

    2006-12-15

    This dissertation presents the results of a research agenda aimed at improving integration and stability in nanocrystal-based solar cells through advances in active materials and device architectures. The introduction of 3-dimensional nanocrystals illustrates the potential for improving transport and percolation in hybrid solar cells and enables novel fabrication methods for optimizing integration in these systems. Fabricating cells by sequential deposition allows for solution-based assembly of hybrid composites with controlled and well-characterized dispersion and electrode contact. Hyperbranched nanocrystals emerge as a nearly ideal building block for hybrid cells, allowing the controlled morphologies targeted by templated approaches to be achieved in an easily fabricated solution-cast device. In addition to offering practical benefits to device processing, these approaches offer fundamental insight into the operation of hybrid solar cells, shedding light on key phenomena such as the roles of electrode-contact and percolation behavior in these cells. Finally, all-inorganic nanocrystal solar cells are presented as a wholly new cell concept, illustrating that donor-acceptor charge transfer and directed carrier diffusion can be utilized in a system with no organic components, and that nanocrystals may act as building blocks for efficient, stable, and low-cost thin-film solar cells.

  16. Solar Cells: Spin-Cast Bulk Heterojunction Solar Cells: A Dynamical...

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

    Solar Cells: Spin-Cast Bulk Heterojunction Solar Cells: A Dynamical Investigation Solar Cells: Spin-Cast Bulk Heterojunction Solar Cells: A Dynamical Investigation Print Wednesday,...

  17. Application of ITO/Al reflectors for increasing the efficiency of single-crystal silicon solar cells

    SciTech Connect (OSTI)

    Kopach, V. R.; Kirichenko, M. V. Khrypunov, G. S.; Zaitsev, R. V.

    2010-06-15

    It is shown that an increase in the efficiency and manufacturability of single-junction single-crystal silicon photoelectric converters of solar energy requires the use of a back-surface reflector based on conductive transparent indium-tin oxide (ITO) 0.25-2 {mu}m thick. To increase the efficiency and reduce the sensitivity to the angle of light incidence on the photoreceiving surface of multijunction photoelectric converters with vertical diode cells based on single-crystal silicon, ITO/Al reflectors with an ITO layer >1 {mu}m thick along vertical boundaries of diode cells should be fabricated. The experimental study of multijunction photoelectric converters with ITO/Al reflectors at diode cell boundaries shows the necessity of modernizing the used technology of ITO layers to achieve their theoretically calculated thickness.

  18. Multijunction photovoltaic device and fabrication method

    DOE Patents [OSTI]

    Arya, Rajeewa R.; Catalano, Anthony W.

    1993-09-21

    A multijunction photovoltaic device includes first and second amorphous silicon PIN photovoltaic cells in a stacked arrangement. An interface layer, composed of a doped silicon compound, is disposed between the two cells and has a lower bandgap than the respective n- and p-type adjacent layers of the first and second cells. The interface layer forms an ohmic contact with the one or the adjacent cell layers of the same conductivity type, and a tunnel junction with the other of the adjacent cell layers. The disclosed device is fabricated by a glow discharge process.

  19. 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.

  20. Energy Yield Determination of Concentrator Solar Cells using Laboratory Measurements: Preprint

    SciTech Connect (OSTI)

    Geisz, John F.; Garcia, Ivan; McMahon, William E.; Steiner, Myles A.; Ochoa, Mario; France, Ryan M.; Habte, Aron; Friedman, Daniel J.

    2015-09-14

    The annual energy conversion efficiency is calculated for a four junction inverted metamorphic solar cell that has been completely characterized in the laboratory at room temperature using measurements fit to a comprehensive optoelectronic model of the multijunction solar cells. A simple model of the temperature dependence is used to predict the performance of the solar cell under varying temperature and spectra characteristic of Golden, CO for an entire year. The annual energy conversion efficiency is calculated by integrating the predicted cell performance over the entire year. The effects of geometric concentration, CPV system thermal characteristics, and luminescent coupling are highlighted. temperature and spectra characteristic of Golden, CO for an entire year. The annual energy conversion efficiency is calculated by integrating the predicted cell performance over the entire year. The effects of geometric concentration, CPV system thermal characteristics, and luminescent coupling are highlighted.

  1. Cooperative Research between NREL and Solar Junction Corp: Cooperative Research and Development Final Report, CRADA Number CRD-08-306

    SciTech Connect (OSTI)

    Friedman, D.

    2015-03-01

    NREL and Solar Junction Corp. will perform cooperative research on materials and devices that are alternatives to standard approaches with the goal of improving solar cell efficiency while lowering cost. The general purpose of this work is to model the performance of a multi-junction concentrator cell of Solar Junction, Inc. design under normal concentrator operating conditions.

  2. GaNPAs Solar Cells that Can Be Lattice-Matched to Silicon

    SciTech Connect (OSTI)

    Geisz, J. F.; Friedman, D. J.; McMahon, W. E.; Ptak, A. J.; Kibbler, A. E.; Olson, J. M.; Kurtz, S.; Kramer, C.; Young, M.; Duda, A.; Reedy, R. C.; Keyes, B. M.; Dippo, P.; Metzger, W. K.

    2003-05-01

    III-V semiconductors grown on silicon substrates are very attractive for lower-cost, high-efficiency multijunction solar cells, but lattice-mismatched alloys that result in high dislocation densities have been unable to achieve satisfactory performance. GaNxP1-x-yAsy is a direct-gap III-V alloy that can be grown lattice-matched to Si when y= 4.7x - 0.1. We have proposed the use of lattice-matched GaNPAs on silicon for high-efficiency multijunction solar cells. We have grown GaNxP1-x-yAsy on GaP (with a similar lattice constant to silicon) by metal-organic chemical vapor phase epitaxy with direct bandgaps in the range of 1.5 to 2.0 eV. We have demonstrated the performance of single-junction GaNxP1-x-yAsy solar cells grown on GaP substrates and shown improvements in material quality by reducing carbon and hydrogen impurities through optimization of growth conditions. We have achieved quantum efficiencies (QE) in these cells as high as 60% and PL lifetimes as high as 3.0 ns.

  3. Computational Challenges for Nanostructure Solar Cells

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

    Challenges for Nanostructure Solar Cells Computational Challenges for Nanostructure Solar Cells ZZ2.jpg Key Challenges: Current nanostructure solar cells often have energy...

  4. Enabling Thin Silicon Solar Cell Technology

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

    Enabling Thin Silicon Solar Cell Technology Enabling Thin Silicon Solar Cell Technology Print Friday, 21 June 2013 10:49 Generic silicon solar cells showing +45, -45, and ...

  5. Monolithic tandem solar cell

    SciTech Connect (OSTI)

    Wanlass, Mark W.

    1991-01-01

    A single-crystal, monolithic, tandem, photovoltaic solar cell is described which includes (a) an InP substrate having upper and lower surfaces, (b) a first photoactive subcell on the upper surface of the InP substrate, and (c) a second photoactive subcell on the first subcell. The first photoactive subcell is GaInAsP of defined composition. The second subcell is InP. The two subcells are lattice matched. The solar cell can be provided as a two-terminal device or a three-terminal device.

  6. Device characterization for design optimization of 4 junction inverted metamorphic concentrator solar cells

    SciTech Connect (OSTI)

    Geisz, John F.; France, Ryan M.; Steiner, Myles A.; Friedman, Daniel J.; Garca, Ivn

    2014-09-26

    Quantitative electroluminescence (EL) and luminescent coupling (LC) analysis, along with more conventional characterization techniques, are combined to completely characterize the subcell JV curves within a fourjunction (4J) inverted metamorphic solar cell (IMM). The 4J performance under arbitrary spectral conditions can be predicted from these subcell JV curves. The internal radiative efficiency (IRE) of each junction has been determined as a function of current density from the external radiative efficiency using optical modeling, but this required the accurate determination of the individual junction current densities during the EL measurement as affected by LC. These measurement and analysis techniques can be applied to any multijunction solar cell. The 4J IMM solar cell used to illustrate these techniques showed excellent junction quality as exhibited by high IRE and a one-sun AM1.5D efficiency of 36.3%. This device operates up to 1000 suns without limitations due to any of the three tunnel junctions.

  7. Solar Cell Simulation

    K-12 Energy Lesson Plans and Activities Web site (EERE)

    Students model the flow of energy from the sun as it enters a photovoltaic cell, moves along a wire and powers a load. The game-like atmosphere involves the younger students and helps them understand the continuous nature of the flow of energy. For a related lesson, please see the activity “Solar Powered System” (PDF 430 KB).

  8. Amorphous semiconductor solar cell

    DOE Patents [OSTI]

    Dalal, Vikram L.

    1981-01-01

    A solar cell comprising a back electrical contact, amorphous silicon semiconductor base and junction layers and a top electrical contact includes in its manufacture the step of heat treating the physical junction between the base layer and junction layer to diffuse the dopant species at the physical junction into the base layer.

  9. 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.

  10. Leakage pathway layer for solar cell

    SciTech Connect (OSTI)

    Luan, Andy; Smith, David; Cousins, Peter; Sun, Sheng

    2015-12-01

    Leakage pathway layers for solar cells and methods of forming leakage pathway layers for solar cells are described.

  11. Microstructure of amorphous-silicon-based solar cell materials by small-angle x-ray scattering. Annual subcontract report, 6 April 1994--5 April 1995

    SciTech Connect (OSTI)

    Williamson, D.L.

    1995-08-01

    The general objective of this research is to provide detailed microstructural information on the amorphous-silicon-based, thin-film materials under development for improved multijunction solar cells. The experimental technique used is small-angle x-ray scattering (SAXS) providing microstructural data on microvoid fractions, sizes, shapes, and their preferred orientations. Other microstructural features such as alloy segregation, hydrogen-rich clusters and alloy short-range order are probed.

  12. Multijunction photovoltaic device and method of manufacture

    DOE Patents [OSTI]

    Arya, Rejeewa R.; Catalano, Anthony W.; Bennett, Murray

    1995-04-04

    A multijunction photovoltaic device includes first, second, and third amorphous silicon p-i-n photovoltaic cells in a stacked arrangement. The intrinsic layers of the second and third cells are formed of a-SiGe alloys with differing ratios of Ge such that the bandgap of the intrinsic layers respectively decrease from the first uppermost cell to the third lowermost cell. An interface layer, composed of a doped silicon compound, is disposed between the two cells and has a lower bandgap than the respective n- and p-type adjacent layers of the first and second cells. The interface layer forms an ohmic contact with the one of the adjacent cell layers of the same conductivity type, and a tunnel junction with the other of the adjacent cell layers.

  13. Solar Cells Hellas SA | Open Energy Information

    Open Energy Info (EERE)

    Cells Hellas SA Jump to: navigation, search Name: Solar Cells Hellas SA Place: Athens, Greece Product: Greek manufacturer of PV wafers, cells and modules. References: Solar Cells...

  14. Temperature coefficients for GaInP/GaAs/GaInNAsSb solar cells

    SciTech Connect (OSTI)

    Aho, Arto; Isoaho, Riku; Tukiainen, Antti; Polojärvi, Ville; Aho, Timo; Raappana, Marianna; Guina, Mircea

    2015-09-28

    We report the temperature coefficients for MBE-grown GaInP/GaAs/GaInNAsSb multijunction solar cells and the corresponding single junction sub-cells. Temperature-dependent current-voltage measurements were carried out using a solar simulator equipped with a 1000 W Xenon lamp and a three-band AM1.5D simulator. The triple-junction cell exhibited an efficiency of 31% at AM1.5G illumination and an efficiency of 37–39% at 70x real sun concentration. The external quantum efficiency was also measured at different temperatures. The temperature coefficients up to 80°C, for the open circuit voltage, the short circuit current density, and the conversion efficiency were determined to be −7.5 mV/°C, 0.040 mA/cm{sup 2}/°C, and −0.09%/°C, respectively.

  15. Solar cell module lamination process

    DOE Patents [OSTI]

    Carey, Paul G.; Thompson, Jesse B.; Aceves, Randy C.

    2002-01-01

    A solar cell module lamination process using fluoropolymers to provide protection from adverse environmental conditions and thus enable more extended use of solar cells, particularly in space applications. A laminate of fluoropolymer material provides a hermetically sealed solar cell module structure that is flexible and very durable. The laminate is virtually chemically inert, highly transmissive in the visible spectrum, dimensionally stable at temperatures up to about 200.degree. C. highly abrasion resistant, and exhibits very little ultra-violet degradation.

  16. Monolithic tandem solar cell

    DOE Patents [OSTI]

    Wanlass, M.W.

    1994-06-21

    A single-crystal, monolithic, tandem, photovoltaic solar cell is described which includes (a) an InP substrate having upper and lower surfaces, (b) a first photoactive subcell on the upper surface of the InP substrate, (c) a second photoactive subcell on the first subcell; and (d) an optically transparent prismatic cover layer over the second subcell. The first photoactive subcell is GaInAsP of defined composition. The second subcell is InP. The two subcells are lattice matched. 9 figs.

  17. Monolithic tandem solar cell

    DOE Patents [OSTI]

    Wanlass, Mark W. (Golden, CO)

    1994-01-01

    A single-crystal, monolithic, tandem, photovoltaic solar cell is described which includes (a) an InP substrate having upper and lower surfaces, (b) a first photoactive subcell on the upper surface of the InP substrate, (c) a second photoactive subcell on the first subcell; and (d) an optically transparent prismatic cover layer over the second subcell. The first photoactive subcell is GaInAsP of defined composition. The second subcell is InP. The two subcells are lattice matched.

  18. NREL: Measurements and Characterization - Cell Current Versus Voltage (I-V)

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

    Cell Current Versus Voltage (I-V) The National Renewable Energy Laboratory Device Performance group uses three I-V systems to measure performance of individual solar cells. We use two systems for solar concentrator cells - a continuous-illumination concentrator and a high-intensity pulsed solar simulator. For non-concentrator solar cells and multijunction devices we use a Spectrolab X-25 solar simulator. The Spectrolab X-25 test stage also accommodates small modules. The following table provides

  19. Current flow and potential efficiency of solar cells based on GaAs and GaSb p-n junctions

    SciTech Connect (OSTI)

    Andreev, V. M.; Evstropov, V. V.; Kalinovsky, V. S. Lantratov, V. M.; Khvostikov, V. P.

    2009-05-15

    Dependence of the efficiency of single-junction and multijunction solar cells on the mechanisms of current flow in photoactive p-n junctions, specifically on the form of the dark current-voltage characteristic J-V, has been studied. The resistanceless J-V{sub j} characteristic (with the series resistance disregarded) of a multijunction solar cell has the same shape as the characteristic of a single-junction cell: both feature a set of exponential portions. This made it possible to develop a unified analytical method for calculating the efficiency of singlejunction and multijunction solar cells. The equation relating the efficiency to the photogenerated current at each portion of the J-V{sub j} characteristic is derived. For p-n junctions in GaAs and GaSb, the following characteristics were measured: the dark J-V characteristic, the dependence of the open-circuit voltage on the illumination intensity P-V{sub OC}, and the dependence of the luminescence intensity on the forward current L-J. Calculated dependences of potential efficiency (under idealized condition for equality to unity of external quantum yield) on the photogenerated current for single-junction GaAs and GaSb solar cells and a GaAs/GaSb tandem are plotted. The form of these dependences corresponds to the shape of J-V{sub j} characteristics: there are the diffusion- and recombination-related portions; in some cases, the tunneling-trapping portion is also observed. At low degrees of concentration of solar radiation (C < 10), an appreciable contribution to photogenerated current is made by recombination component. It is an increase in this component in the case of irradiation with 6.78-MeV protons or 1-MeV electrons that brings about a decrease in the efficiency of conversion of unconcentrated solar radiation.

  20. Research on stable, high-efficiency amorphous silicon multijunction modules

    SciTech Connect (OSTI)

    Ghosh, M.; DelCueto, J.: Kampas, F.; Xi, J. )

    1993-02-01

    This report describes results from the first phase of a three-phase contract for the development of stable, high-efficiency, same-band-gap, amorphous silicon (a-Si) multijunction photovoltaic (PV) modules. The program involved improving the properties of individual layers of semiconductor and non-semiconductor materials and small-area single-junction and multijunction devices, as well as the multijunction modules. The semiconductor materials research was performed on a-Si p, i, and n layers, and on microcrystalline silicon n layers. These were deposited using plasma-enhanced chemical vapor deposition. The non-semiconductor materials studied were tin oxide, for use as a transparent-conducting-oxide (TCO), and zinc oxide, for use as a back reflector and as a buffer layer between the TCO and the semiconductor layers. Tin oxide was deposited using atmospheric-pressure chemical vapor deposition. Zinc oxide was deposited using magnetron sputtering. The research indicated that the major challenge in the fabrication of a-Si multijunction PV modules is the contact between the two p-i-n cells. A structure that has low optical absorption but that also facilitates the recombination of electrons from the first p-i-n structure with holes from the second p-i-n structure is required. Non-semiconductor layers and a-Si semiconductor layers were tested without achieving the desired result.

  1. Biomimetic Dye Molecules for Solar Cells

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

    Biomimetic Dye Molecules for Solar Cells Print Pressing energy problems provide opportunities for solid-state physicists and chemists to solve a major challenge: solar cell...

  2. Biomimetic Dye Molecules for Solar Cells

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

    Dye Molecules for Solar Cells Print Pressing energy problems provide opportunities for solid-state physicists and chemists to solve a major challenge: solar cell adoption....

  3. Biomimetic Dye Molecules for Solar Cells

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

    Pressing energy problems provide opportunities for solid-state physicists and chemists to solve a major challenge: solar cell adoption. Though solar cells can use energy directly ...

  4. Multiple Exciton Generation Solar Cells

    SciTech Connect (OSTI)

    Luther, J. M.; Semonin, O. E.; Beard, M. C.; Gao, J.; Nozik, A. J.

    2012-01-01

    Heat loss is the major factor limiting traditional single junction solar cells to a theoretical efficiency of 32%. Multiple Exciton Generation (MEG) enables efficient use of the solar spectrum yielding a theoretical power conversion efficiency of 44% in solar cells under 1-sun conditions. Quantum-confined semiconductors have demonstrated the ability to generate multiple carriers but present-day materials deliver efficiencies far below the SQ limit of 32%. Semiconductor quantum dots of PbSe and PbS provide an active testbed for developing high-efficiency, inexpensive solar cells benefitting from quantum confinement effects. Here, we will present recent work of solar cells employing MEG to yield external quantum efficiencies exceeding 100%.

  5. Module level solutions to solar cell polarization

    DOE Patents [OSTI]

    Xavier, Grace , Li; Bo

    2012-05-29

    A solar cell module includes interconnected solar cells, a transparent cover over the front sides of the solar cells, and a backsheet on the backsides of the solar cells. The solar cell module includes an electrical insulator between the transparent cover and the front sides of the solar cells. An encapsulant protectively packages the solar cells. To prevent polarization, the insulator has resistance suitable to prevent charge from leaking from the front sides of the solar cells to other portions of the solar cell module by way of the transparent cover. The insulator may be attached (e.g., by coating) directly on an underside of the transparent cover or be a separate layer formed between layers of the encapsulant. The solar cells may be back junction solar cells.

  6. Un-Nanostructuring Solar Cells | ANSER Center | Argonne-Northwestern...

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

    Un-Nanostructuring Solar Cells Home > Research > ANSER Research Highlights > Un-Nanostructuring Solar Cells...

  7. Solar cell with back side contacts

    DOE Patents [OSTI]

    Nielson, Gregory N; Okandan, Murat; Cruz-Campa, Jose Luis; Resnick, Paul J; Wanlass, Mark Woodbury; Clews, Peggy J

    2013-12-24

    A III-V solar cell is described herein that includes all back side contacts. Additionally, the positive and negative electrical contacts contact compoud semiconductor layers of the solar cell other than the absorbing layer of the solar cell. That is, the positive and negative electrical contacts contact passivating layers of the solar cell.

  8. Solar Cell Wafer

    Broader source: Energy.gov [DOE]

    This photograph features a multi-crystal silicon wafer developed by CaliSolar undergoing performance testing at the National Renewable Energy Laboratory (NREL). The laboratory’s High-Intensity...

  9. TOPCAT Solar Cell Alignment & Energy Concentration Technology...

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

    Thermal Solar Thermal Find More Like This Return to Search TOPCAT Solar Cell Alignment & Energy Concentration Technology Sandia National Laboratories Contact SNL About This ...

  10. State-of-the-Art Solar Simulator Reduces Measurement Time and Uncertainty (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2012-04-01

    One-Sun Multisource Solar Simulator (OSMSS) brings accurate energy-rating predictions that account for the nonlinear behavior of multijunction photovoltaic devices. The National Renewable Energy Laboratory (NREL) is one of only a few International Organization for Standardization (ISO)-accredited calibration labs in the world for primary and secondary reference cells and modules. As such, it is critical to seek new horizons in developing simulators and measurement methods. Current solar simulators are not well suited for accurately measuring multijunction devices. To set the electrical current to each junction independently, simulators must precisely tune the spectral content with no overlap between the wavelength regions. Current simulators do not have this capability, and the overlaps lead to large measurement uncertainties of {+-}6%. In collaboration with LabSphere, NREL scientists have designed and implemented the One-Sun Multisource Solar Simulator (OSMSS), which enables automatic spectral adjustment with nine independent wavelength regions. This fiber-optic simulator allows researchers and developers to set the current to each junction independently, reducing errors relating to spectral effects. NREL also developed proprietary software that allows this fully automated simulator to rapidly 'build' a spectrum under which all junctions of a multijunction device are current matched and behave as they would under a reference spectrum. The OSMSS will reduce the measurement uncertainty for multijunction devices, while significantly reducing the current-voltage measurement time from several days to minutes. These features will enable highly accurate energy-rating predictions that take into account the nonlinear behavior of multijunction photovoltaic devices.

  11. 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.

  12. Development of concentrator solar cells

    SciTech Connect (OSTI)

    Not Available

    1994-08-01

    A limited pilot production run on PESC silicon solar cells for use at high concentrations (200 to 400 suns) is summarized. The front contact design of the cells was modified for operation without prismatic covers. The original objective of the contract was to systematically complete a process consolidation phase, in which all the, process improvements developed during the contract would be combined in a pilot production run. This pilot run was going to provide, a basis for estimating cell costs when produced at high throughput. Because of DOE funding limitations, the Photovoltaic Concentrator Initiative is on hold, and Applied Solar`s contract was operated at a low level of effort for most of 1993. The results obtained from the reduced scope pilot run showed the effects of discontinuous process optimization and characterization. However, the run provided valuable insight into the technical areas that can be optimized to achieve the original goals of the contract.

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

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

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

  14. Plastic Solar Cells See Bright Future | ANSER Center | Argonne...

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

    Plastic Solar Cells See Bright Future Home > News & Events > Plastic Solar Cells See Bright Future Plastic Solar Cells See Bright Future Evanston, Ill---Energy consumption is ...

  15. NREL: Solar Research - Potential of Perovskite Solar Cells Featured...

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

    If not, you'll probably hear more about them soon. Perovskites are a family of materials receiving considerable attention by solar cell researchers due to the rapid rise of solar ...

  16. Game-Changing Advancements in Solar Energy | Department of Energy

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

    Game-Changing Advancements in Solar Energy Game-Changing Advancements in Solar Energy Addthis Record-Breaking Solar 1 of 5 Record-Breaking Solar This concentrating photovoltaic (CPV) cell -- which uses a focused lens to magnify light to 418 times the intensity of the sun -- earned an R&D100 Award and set a new world record of 43.5 percent for solar cell conversion efficiency. The technology is based on high-efficiency multijunction research pioneered by the National Renewable Energy

  17. 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.

  18. Nontoxic quantum dot research improves solar cells

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

    Solar cells made with low-cost, nontoxic copper-based quantum dots can achieve ... LOS ALAMOS, N.M., Dec. 10, 2013-Solar cells made with low-cost, nontoxic copper-based ...

  19. Biomimetic Dye Molecules for Solar Cells

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

    provide opportunities for solid-state physicists and chemists to solve a major challenge: solar cell adoption. Though solar cells can use energy directly from the Sun to produce...

  20. Cermet layer for amorphous silicon solar cells

    DOE Patents [OSTI]

    Hanak, Joseph J.

    1979-01-01

    A transparent high work function metal cermet forms a Schottky barrier in a Schottky barrier amorphous silicon solar cell and adheres well to the P+ layer in a PIN amorphous silicon solar cell.

  1. Compensated amorphous silicon solar cell

    DOE Patents [OSTI]

    Carlson, David E.

    1980-01-01

    An amorphous silicon solar cell incorporates a region of intrinsic hydrogenated amorphous silicon fabricated by a glow discharge wherein said intrinsic region is compensated by P-type dopants in an amount sufficient to reduce the space charge density of said region under illumination to about zero.

  2. Pokeberries Provide Boost for Solar Cells

    Broader source: Energy.gov [DOE]

    Red dye from the pokeberry weed makes their low-cost, fiber-based solar cells even more energy efficient.

  3. Biomimetic Dye Molecules for Solar Cells

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

    Biomimetic Dye Molecules for Solar Cells Print Pressing energy problems provide opportunities for solid-state physicists and chemists to solve a major challenge: solar cell adoption. Though solar cells can use energy directly from the Sun to produce electricity that can be converted efficiently into other kinds of energy, they are currently too costly to compete with traditional (polluting) energy sources. The most cost-effective solar cells are not high-end, high-efficiency single-crystal

  4. Biomimetic Dye Molecules for Solar Cells

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

    Biomimetic Dye Molecules for Solar Cells Print Pressing energy problems provide opportunities for solid-state physicists and chemists to solve a major challenge: solar cell adoption. Though solar cells can use energy directly from the Sun to produce electricity that can be converted efficiently into other kinds of energy, they are currently too costly to compete with traditional (polluting) energy sources. The most cost-effective solar cells are not high-end, high-efficiency single-crystal

  5. Biomimetic Dye Molecules for Solar Cells

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

    Biomimetic Dye Molecules for Solar Cells Print Pressing energy problems provide opportunities for solid-state physicists and chemists to solve a major challenge: solar cell adoption. Though solar cells can use energy directly from the Sun to produce electricity that can be converted efficiently into other kinds of energy, they are currently too costly to compete with traditional (polluting) energy sources. The most cost-effective solar cells are not high-end, high-efficiency single-crystal

  6. Biomimetic Dye Molecules for Solar Cells

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

    Biomimetic Dye Molecules for Solar Cells Print Pressing energy problems provide opportunities for solid-state physicists and chemists to solve a major challenge: solar cell adoption. Though solar cells can use energy directly from the Sun to produce electricity that can be converted efficiently into other kinds of energy, they are currently too costly to compete with traditional (polluting) energy sources. The most cost-effective solar cells are not high-end, high-efficiency single-crystal

  7. Biomimetic Dye Molecules for Solar Cells

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

    Biomimetic Dye Molecules for Solar Cells Biomimetic Dye Molecules for Solar Cells Print Wednesday, 28 April 2010 00:00 Pressing energy problems provide opportunities for solid-state physicists and chemists to solve a major challenge: solar cell adoption. Though solar cells can use energy directly from the Sun to produce electricity that can be converted efficiently into other kinds of energy, they are currently too costly to compete with traditional (polluting) energy sources. The most

  8. Key Physical Mechanisms in Nanostructured Solar Cells

    SciTech Connect (OSTI)

    Dr Stephan Bremner

    2010-07-21

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

  9. Process of making solar cell module

    DOE Patents [OSTI]

    Packer, M.; Coyle, P.J.

    1981-03-09

    A process is presented for the manufacture of solar cell modules. A solution comprising a highly plasticized polyvinyl butyral is applied to a solar cell array. The coated array is dried and sandwiched between at last two sheets of polyvinyl butyral and at least two sheets of a rigid transparent member. The sandwich is laminated by the application of heat and pressure to cause fusion and bonding of the solar cell array with the rigid transparent members to produce a solar cell module.

  10. Biomimetic Dye Molecules for Solar Cells

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

    Biomimetic Dye Molecules for Solar Cells Print Pressing energy problems provide opportunities for solid-state physicists and chemists to solve a major challenge: solar cell adoption. Though solar cells can use energy directly from the Sun to produce electricity that can be converted efficiently into other kinds of energy, they are currently too costly to compete with traditional (polluting) energy sources. The most cost-effective solar cells are not high-end, high-efficiency single-crystal

  11. Biomimetic Dye Molecules for Solar Cells

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

    Biomimetic Dye Molecules for Solar Cells Print Pressing energy problems provide opportunities for solid-state physicists and chemists to solve a major challenge: solar cell adoption. Though solar cells can use energy directly from the Sun to produce electricity that can be converted efficiently into other kinds of energy, they are currently too costly to compete with traditional (polluting) energy sources. The most cost-effective solar cells are not high-end, high-efficiency single-crystal

  12. Biomimetic Dye Molecules for Solar Cells

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

    Biomimetic Dye Molecules for Solar Cells Print Pressing energy problems provide opportunities for solid-state physicists and chemists to solve a major challenge: solar cell adoption. Though solar cells can use energy directly from the Sun to produce electricity that can be converted efficiently into other kinds of energy, they are currently too costly to compete with traditional (polluting) energy sources. The most cost-effective solar cells are not high-end, high-efficiency single-crystal

  13. Biomimetic Dye Molecules for Solar Cells

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

    Biomimetic Dye Molecules for Solar Cells Print Pressing energy problems provide opportunities for solid-state physicists and chemists to solve a major challenge: solar cell adoption. Though solar cells can use energy directly from the Sun to produce electricity that can be converted efficiently into other kinds of energy, they are currently too costly to compete with traditional (polluting) energy sources. The most cost-effective solar cells are not high-end, high-efficiency single-crystal

  14. Effects of Bismuth on Wide-Depletion-Width GaInNAs Solar Cells

    SciTech Connect (OSTI)

    Ptak, A. J.; France, R.; Jiang, C.-S.; Reedy, R. C.

    2008-05-01

    GaInNAs solar cells could be useful in next-generation multijunction solar cells if issues surrounding low photocurrents and photovoltages are surmounted. Wide-depletion-width devices generate significant photocurrent using a p-i-n structure grown by molecular beam epitaxy, but these depletion widths are only realized in a region of parameter space that leads to rough surface morphologies. Here, bismuth is explored as a surfactant for the growth of GaInNAs solar cells. Very low fluxes of Bi are effective at maintaining smooth surfaces, even at high growth temperatures and In contents. However, Bi also increases the net donor concentration in these materials, manifested in our n-on-p device structures as a pn-junction that moves deeper into the base layer with increasing Bi fluxes. Quantum efficiency modeling and scanning kelvin probe microscopy measurements confirm the type conversion of the base layer from p type to n type. Bi incorporation in GaAsBi samples shows signs of surface segregation, leading to a finite buildup time, and this effect may lead to slow changes in the electrical properties of the GaInNAs(Bi) devices. Bi also appears to create a defect level, although this defect level is not deleterious enough to increase the dark current in the devices.

  15. When Function Follows Form: Plastic Solar Cells | ANSER Center...

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

    When Function Follows Form: Plastic Solar Cells Home > Research > ANSER Research Highlights > When Function Follows Form: Plastic Solar Cells...

  16. 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.

  17. Mixed ternary heterojunction solar cell

    SciTech Connect (OSTI)

    Chen, Wen S.; Stewart, John M.

    1992-08-25

    A thin film heterojunction solar cell and a method of making it has a p-type layer of mixed ternary I-III-VI.sub.2 semiconductor material in contact with an n-type layer of mixed binary II-VI semiconductor material. The p-type semiconductor material includes a low resistivity copper-rich region adjacent the back metal contact of the cell and a composition gradient providing a minority carrier mirror that improves the photovoltaic performance of the cell. The p-type semiconductor material preferably is CuInGaSe.sub.2 or CuIn(SSe).sub.2.

  18. Tianjin Jinneng Solar Cell Co Ltd | Open Energy Information

    Open Energy Info (EERE)

    Solar Cell Co Ltd Jump to: navigation, search Name: Tianjin Jinneng Solar Cell Co Ltd Place: Tianjin Municipality, China Zip: 300384 Sector: Solar Product: Chinese manufacturer of...

  19. Hybrid emitter all back contact solar cell

    DOE Patents [OSTI]

    Loscutoff, Paul; Rim, Seung

    2016-04-12

    An all back contact solar cell has a hybrid emitter design. The solar cell has a thin dielectric layer formed on a backside surface of a single crystalline silicon substrate. One emitter of the solar cell is made of doped polycrystalline silicon that is formed on the thin dielectric layer. The other emitter of the solar cell is formed in the single crystalline silicon substrate and is made of doped single crystalline silicon. The solar cell includes contact holes that allow metal contacts to connect to corresponding emitters.

  20. Enabling Thin Silicon Solar Cell Technology

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

    Enabling Thin Silicon Solar Cell Technology Enabling Thin Silicon Solar Cell Technology Print Friday, 21 June 2013 10:49 Generic silicon solar cells showing +45°, -45°, and dendritic crack patterns. The effort to shift U.S. energy reliance from fossil fuels to renewable sources has spurred companies to reduce the cost and increase the reliability of their solar photovoltaics (SPVs). The use of thinner silicon in SPV technologies is being widely adopted because it significantly reduces costs;

  1. Compensated amorphous silicon solar cell

    DOE Patents [OSTI]

    Devaud, Genevieve

    1983-01-01

    An amorphous silicon solar cell including an electrically conductive substrate, a layer of glow discharge deposited hydrogenated amorphous silicon over said substrate and having regions of differing conductivity with at least one region of intrinsic hydrogenated amorphous silicon. The layer of hydrogenated amorphous silicon has opposed first and second major surfaces where the first major surface contacts the electrically conductive substrate and an electrode for electrically contacting the second major surface. The intrinsic hydrogenated amorphous silicon region is deposited in a glow discharge with an atmosphere which includes not less than about 0.02 atom percent mono-atomic boron. An improved N.I.P. solar cell is disclosed using a BF.sub.3 doped intrinsic layer.

  2. 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.

  3. Three-junction solar cell

    DOE Patents [OSTI]

    Ludowise, Michael J. (Cupertino, CA)

    1986-01-01

    A photovoltaic solar cell is formed in a monolithic semiconductor. The cell contains three junctions. In sequence from the light-entering face, the junctions have a high, a medium, and a low energy gap. The lower junctions are connected in series by one or more metallic members connecting the top of the lower junction through apertures to the bottom of the middle junction. The upper junction is connected in voltage opposition to the lower and middle junctions by second metallic electrodes deposited in holes 60 through the upper junction. The second electrodes are connected to an external terminal.

  4. High Efficiency Low-Cost Perovskite Solar Cell Modules

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

    High Efficiency, Low-Cost Perovskite Solar Cell Modules High Efficiency, Low-Cost Perovskite Solar Cell Modules Perovskite solar cells have the ability to greatly increase the adoption of solar power technology: * Low cost - as much as 75% less than current Si solar cells * High efficiency - equal to and possibly slightly greater than Si solar cell technology * Realization of solar panels for grid- based electricity generation * Increased adoption of solar cell technology across the world

  5. Spectral sensitization of nanocrystalline solar cells

    DOE Patents [OSTI]

    Spitler, Mark T.; Ehret, Anne; Stuhl, Louis S.

    2002-01-01

    This invention relates to dye sensitized polycrystalline photoelectrochemical solar cells for use in energy transduction from light to electricity. It concerns the utility of highly absorbing organic chromophores as sensitizers in such cells and the degree to which they may be utilized alone and in combination to produce an efficient photoelectrochemical cell, e.g., a regenerative solar cell.

  6. Cross-sectional electrostatic force microscopy of thin-film solar cells

    SciTech Connect (OSTI)

    Ballif, C.; Moutinho, H. R.; Al-Jassim, M. M.

    2001-01-15

    In a recent work, we showed that atomic force microscopy (AFM) is a powerful technique to image cross sections of polycrystalline thin films. In this work, we apply a modification of AFM, namely, electrostatic force microscopy (EFM), to investigate the electronic properties of cleaved II--VI and multijunction thin-film solar cells. We cleave the devices in such a way that they are still working with their nominal photovoltaic efficiencies and can be polarized for the measurements. This allows us to differentiate between surface effects (work function and surface band bending) and bulk device properties. In the case of polycrystalline CdTe/CdS/SnO{sub 2}/glass solar cells, we find a drop of the EFM signal in the area of the CdTe/CdS interface ({+-}50 nm). This drop varies in amplitude and sign according to the applied external bias and is compatible with an n-CdS/p-CdTe heterojunction model, thereby invalidating the possibility of a deeply buried n-p CdTe homojunction. In the case of a triple-junction GaInP/GaAs/Ge device, we observe a variation of the EFM signal linked to both the material work-function differences and to the voltage bias applied to the cell. We attempt a qualitative explanation of the results and discuss the implications and difficulties of the EFM technique for the study of such thin-film devices.

  7. Development of a 2.0 eV AlGaInP Solar Cell Grown by OMVPE

    SciTech Connect (OSTI)

    Perl, Emmett E.; Simon, John; Geisz, John F.; Olavarria, Waldo; Young, Michelle; Duda, Anna; Dippo, Pat; Friedman, Daniel J.; Steiner, Myles A.

    2015-06-14

    AlGaInP solar cells with a bandgap (Eg) of ~2.0 eV are developed for use in next-generation multijunction photovoltaic devices. This material system is of great interest for both space and concentrator photovoltaics due to its high bandgap, which enables the development of high-efficiency five-junction and six-junction devices and is also useful for solar cells operated at elevated temperatures. In this work, we explore the conditions for the Organometallic Vapor Phase Epitaxy (OMVPE) growth of AlGaInP and study their effects on cell performance. A ~2.0 eV AlGaInP solar cell is demonstrated with an open circuit voltage (VOC) of 1.59V, a bandgap-voltage offset (WOC) of 420mV, a fill factor (FF) of 88.0%, and an efficiency of 14.8%. These AlGaInP cells have attained a similar FF, WOC and internal quantum efficiency (IQE) to the best upright GaInP cells grown in our lab to date.

  8. Search for new solar cell heats up

    SciTech Connect (OSTI)

    Lipkin, R.

    1990-11-05

    Researchers are in the process of developing an organic solar energy cell with a plasticlike material that simplifies the complicated process of creating a working cell - one that is cheap, easy to produce and has a variety of potential applications. The chemical is polyacetylene and can be painted on anything to become a solar cell.

  9. Flipping crystals improves solar-cell performance

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

    Flipping crystals improves solar-cell performance Flipping crystals improves solar-cell performance Perovskite research team spin-casts crystals for efficient and resilient optoelectronic devices. July 6, 2016 Perovskite research team spin-casts crystals for efficient and resilient optoelectronic devices. Three types of large-area solar cells made out of two-dimensional perovskites. At left, a room-temperature cast film; upper middle is a sample with the problematic band gap, and at right is the

  10. Bypass diode for a solar cell

    DOE Patents [OSTI]

    Rim, Seung Bum; Kim, Taeseok; Smith, David D.; Cousins, Peter J.

    2012-03-13

    Bypass diodes for solar cells are described. In one embodiment, a bypass diode for a solar cell includes a substrate of the solar cell. A first conductive region is disposed above the substrate, the first conductive region of a first conductivity type. A second conductive region is disposed on the first conductive region, the second conductive region of a second conductivity type opposite the first conductivity type.

  11. Solar Cell Modules With Improved Backskin

    DOE Patents [OSTI]

    Gonsiorawski, Ronald C.

    2003-12-09

    A laminated solar cell module comprises a front light transmitting support, a plurality of interconnected solar cells encapsulated by a light-transmitting encapsulant material, and an improved backskin formed of an ionomer/nylon alloy. The improved backskin has a toughness and melting point temperature sufficiently great to avoid any likelihood of it being pierced by any of the components that interconnect the solar cells.

  12. Could Material Defects Actually Improve Solar Cells?

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

    Could Material Defects Actually Improve Solar Cells? Could Material Defects Actually Improve Solar Cells? March 21, 2016 Contact: Kathy Kincade, kkincade@lbl.gov, +1 510 495 2124 NRELsolarcell Scientists at the U.S. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL) are using supercomputers to study what may seem paradoxical: certain defects in silicon solar cells may actually improve their performance. The findings, published January 11, 2016 in Applied Physics Letters,

  13. Solar Foundational Program to Advance Cell Efficiency Round 1...

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

    crystalline-Si solar cells for significant efficiency improvements and cost reductions. ... and monocrystalline-Si solar cells, reduce cell costs by 0.10W, and ...

  14. Biomimetic Dye Molecules for Solar Cells

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

    Organic molecules in dye-sensitized solar cells exhibit great potential to increase the efficiency and reduce the cost of photovoltaic power generation by allowing a wide variety ...

  15. Pennsylvania Company Develops Solar Cell Printing Technology

    Broader source: Energy.gov [DOE]

    The technology uses Plextronics’ conductive inks that can be printed by manufacturers worldwide to make solar cells, potentially as easily as they might print a newspaper.

  16. Could Material Defects Actually Improve Solar Cells?

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

    Deep-level defects frequently hamper the efficiency of solar cells, but NREL theoretical research suggests that defects with properly engineered energy levels can improve carrier ...

  17. Solar Cell Research at Lawrence Berkeley

    Broader source: Energy.gov [DOE]

    This photograph features the Solar cell research in the molecular foundry at Lawrence Berkeley National Laboratory. Pictured is researcher Claudia Piliego.

  18. Efficient Polymer Solar Cells - Energy Innovation Portal

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

    Find More Like This Return to Search Efficient Polymer Solar Cells Ames Laboratory Contact ... Ames Laboratory researchers have developed a process for producing more efficient polymer ...

  19. Front contact solar cell with formed emitter

    DOE Patents [OSTI]

    Cousins, Peter John

    2014-11-04

    A bipolar solar cell includes a backside junction formed by an N-type silicon substrate and a P-type polysilicon emitter formed on the backside of the solar cell. An antireflection layer may be formed on a textured front surface of the silicon substrate. A negative polarity metal contact on the front side of the solar cell makes an electrical connection to the substrate, while a positive polarity metal contact on the backside of the solar cell makes an electrical connection to the polysilicon emitter. An external electrical circuit may be connected to the negative and positive metal contacts to be powered by the solar cell. The positive polarity metal contact may form an infrared reflecting layer with an underlying dielectric layer for increased solar radiation collection.

  20. Front contact solar cell with formed emitter

    DOE Patents [OSTI]

    Cousins, Peter John

    2012-07-17

    A bipolar solar cell includes a backside junction formed by an N-type silicon substrate and a P-type polysilicon emitter formed on the backside of the solar cell. An antireflection layer may be formed on a textured front surface of the silicon substrate. A negative polarity metal contact on the front side of the solar cell makes an electrical connection to the substrate, while a positive polarity metal contact on the backside of the solar cell makes an electrical connection to the polysilicon emitter. An external electrical circuit may be connected to the negative and positive metal contacts to be powered by the solar cell. The positive polarity metal contact may form an infrared reflecting layer with an underlying dielectric layer for increased solar radiation collection.

  1. Method for processing silicon solar cells

    DOE Patents [OSTI]

    Tsuo, Y. Simon; Landry, Marc D.; Pitts, John R.

    1997-01-01

    The instant invention teaches a novel method for fabricating silicon solar cells utilizing concentrated solar radiation. The solar radiation is concentrated by use of a solar furnace which is used to form a front surface junction and back-surface field in one processing step. The present invention also provides a method of making multicrystallline silicon from amorphous silicon. The invention also teaches a method of texturing the surface of a wafer by forming a porous silicon layer on the surface of a silicon substrate and a method of gettering impurities. Also contemplated by the invention are methods of surface passivation, forming novel solar cell structures, and hydrogen passivation.

  2. Method for processing silicon solar cells

    DOE Patents [OSTI]

    Tsuo, Y.S.; Landry, M.D.; Pitts, J.R.

    1997-05-06

    The instant invention teaches a novel method for fabricating silicon solar cells utilizing concentrated solar radiation. The solar radiation is concentrated by use of a solar furnace which is used to form a front surface junction and back-surface field in one processing step. The present invention also provides a method of making multicrystalline silicon from amorphous silicon. The invention also teaches a method of texturing the surface of a wafer by forming a porous silicon layer on the surface of a silicon substrate and a method of gettering impurities. Also contemplated by the invention are methods of surface passivation, forming novel solar cell structures, and hydrogen passivation. 2 figs.

  3. Solar Cells: Spin-Cast Bulk Heterojunction Solar Cells: A Dynamical

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

    Investigation Solar Cells: Spin-Cast Bulk Heterojunction Solar Cells: A Dynamical Investigation Solar Cells: Spin-Cast Bulk Heterojunction Solar Cells: A Dynamical Investigation Print Wednesday, 03 April 2013 13:32 Spin-coating is extensively used in the lab-based manufacturing of organic solar cells, including most of the record-setting cells. Aram Amassian and co-workers report in this study the first direct observation of photoactive layer formation as it occurs during spin-coating. The

  4. Amorphous silicon solar cell allowing infrared transmission

    DOE Patents [OSTI]

    Carlson, David E.

    1979-01-01

    An amorphous silicon solar cell with a layer of high index of refraction material or a series of layers having high and low indices of refraction material deposited upon a transparent substrate to reflect light of energies greater than the bandgap energy of the amorphous silicon back into the solar cell and transmit solar radiation having an energy less than the bandgap energy of the amorphous silicon.

  5. Biomimetic Dye Molecules for Solar Cells

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

    The most cost-effective solar cells are not high-end, high-efficiency single-crystal devices, but rather low-end cells based on organic molecules or conducting polymers. Vital ...

  6. Fullerene surfactants and their use in polymer solar cells

    SciTech Connect (OSTI)

    Jen, Kwan-Yue; Yip, Hin-Lap; Li, Chang-Zhi

    2015-12-15

    Fullerene surfactant compounds useful as interfacial layer in polymer solar cells to enhance solar cell efficiency. Polymer solar cell including a fullerene surfactant-containing interfacial layer intermediate cathode and active layer.

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

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

    Nanoscale Size Distribution Explains Performance in Solar Cells Organic Solar Cells: Absolute Measurement of Domain Composition and Nanoscale Size Distribution Explains Performance in Solar Cells Organic Solar Cells: Absolute Measurement of Domain Composition and Nanoscale Size Distribution Explains Performance in Solar Cells Print Tuesday, 22 January 2013 00:00 This front cover represents the morphology and resulting device dynamics in organic solar cell blend films of PTB7 and PC71BM, as

  8. New Morphological Paradigm Uncovered in Organic Solar Cells

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

    Improving Solar Cell Models Organic photovoltaics (OPVs), or solar cells, have the potential to provide a low-cost and renewable source of environmentally friendly energy. ...

  9. Polymer Solar Cells: New Materials, 3D Morphology, and Tandem...

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

    to occur with high quantum efficiency and with minimal losses in energy. Presently, the best polymer solar cells reach power ... polymers for efficient (>5%) solar cells ...

  10. 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...

  11. New Morphological Paradigm Uncovered in Organic Solar Cells

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

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

  12. Nanocrystal Solar Cells Squeeze Extra Juice Out of Sunlight ...

    Office of Science (SC) Website

    Nanocrystal Solar Cells Squeeze Extra Juice Out of Sunlight Basic Energy Sciences (BES) ... More Information 12.01.11 Nanocrystal Solar Cells Squeeze Extra Juice Out of Sunlight ...

  13. Solland Solar Cells BV Shanghai | Open Energy Information

    Open Energy Info (EERE)

    Cells BV Shanghai Jump to: navigation, search Name: Solland Solar Cells BV (Shanghai) Place: Shanghai, Shanghai Municipality, China Zip: 200030 Sector: Solar Product:...

  14. Understanding Collection-Related Losses in Organic Solar Cells...

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

    Understanding Collection-Related Losses in Organic Solar Cells Home > Research > ANSER Research Highlights > Understanding Collection-Related Losses in Organic Solar Cells...

  15. Heterojunction solar cell with passivated emitter surface

    DOE Patents [OSTI]

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

    1994-05-31

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

  16. Bypass diode for a solar cell

    DOE Patents [OSTI]

    Rim, Seung Bum; Kim, Taeseok; Smith, David D; Cousins, Peter J

    2013-11-12

    Methods of fabricating bypass diodes for solar cells are described. In once embodiment, a method includes forming a first conductive region of a first conductivity type above a substrate of a solar cell. A second conductive region of a second conductivity type is formed on the first conductive region. In another embodiment, a method includes forming a first conductive region of a first conductivity type above a substrate of a solar cell. A second conductive region of a second conductivity type is formed within, and surrounded by, an uppermost portion of the first conductive region but is not formed in a lowermost portion of the first conductive region.

  17. Heterojunction solar cell with passivated emitter surface

    DOE Patents [OSTI]

    Olson, Jerry M.; Kurtz, Sarah R.

    1994-01-01

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

  18. Solar cell with silicon oxynitride dielectric layer

    SciTech Connect (OSTI)

    Shepherd, Michael; Smith, David D

    2015-04-28

    Solar cells with silicon oxynitride dielectric layers and methods of forming silicon oxynitride dielectric layers for solar cell fabrication are described. For example, an emitter region of a solar cell includes a portion of a substrate having a back surface opposite a light receiving surface. A silicon oxynitride (SiO.sub.xN.sub.y, 0

  19. Hot Electron Photovoltaics Using Low Cost Materials and Simple Cell Design

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

    - Energy Innovation Portal Solar Photovoltaic Solar Photovoltaic Find More Like This Return to Search Hot Electron Photovoltaics Using Low Cost Materials and Simple Cell Design Lawrence Berkeley National Laboratory Contact LBL About This Technology Technology Marketing Summary"Third-generation" PV technologies are being actively pursued in academic research labs. These include nano-optics, multi-junction architectures, multi-exciton, plasmonics, and lower cost tandem cells. The

  20. Cascade solar cell having conductive interconnects

    DOE Patents [OSTI]

    Borden, Peter G.; Saxena, Ram R.

    1982-10-26

    Direct ohmic contact between the cells in an epitaxially grown cascade solar cell is obtained by means of conductive interconnects formed through grooves etched intermittently in the upper cell. The base of the upper cell is directly connected by the conductive interconnects to the emitter of the bottom cell. The conductive interconnects preferably terminate on a ledge formed in the base of the upper cell.

  1. Solar Systems Pty Ltd | Open Energy Information

    Open Energy Info (EERE)

    technology it has developed for concentrating sunlight by a factor of 500 onto multi-junction PV cells, using parabolic dishes. Went into receivership in September 2009....

  2. Solar cell with a gallium nitride electrode

    DOE Patents [OSTI]

    Pankove, Jacques I.

    1979-01-01

    A solar cell which comprises a body of silicon having a P-N junction therein with a transparent conducting N-type gallium nitride layer as an ohmic contact on the N-type side of the semiconductor exposed to solar radiation.

  3. LQ Energy LDK Solar Q Cells JV | Open Energy Information

    Open Energy Info (EERE)

    LQ Energy LDK Solar Q Cells JV Jump to: navigation, search Name: LQ Energy (LDK Solar & Q-Cells JV) Place: Saxony-Anhalt, Germany Sector: Solar Product: Germany-based JV between...

  4. Indium oxide/n-silicon heterojunction solar cells

    DOE Patents [OSTI]

    Feng, Tom; Ghosh, Amal K.

    1982-12-28

    A high photo-conversion efficiency indium oxide/n-silicon heterojunction solar cell is spray deposited from a solution containing indium trichloride. The solar cell exhibits an Air Mass One solar conversion efficiency in excess of about 10%.

  5. Dye-sensitized solar cells

    DOE Patents [OSTI]

    Skotheim, Terje A. [Berkeley, CA

    1980-03-04

    A low-cost dye-sensitized Schottky barrier solar cell comprised of a substrate of semiconductor with an ohmic contact on one face, a sensitizing dye adsorbed onto the opposite face of the semiconductor, a transparent thin-film layer of a reducing agent over the dye, and a thin-film layer of metal over the reducing agent. The ohmic contact and metal layer constitute electrodes for connection to an external circuit and one or the other or both are made transparent to permit light to penetrate to the dye and be absorbed therein for generating electric current. The semiconductor material chosen to be the substrate is one having a wide bandgap and which therefore is transparent; the dye selected is one having a ground state within the bandgap of the semiconductor to generate carriers in the semiconductor, and a first excited state above the conduction band edge of the semiconductor to readily conduct electrons from the dye to the semiconductor; the reducing agent selected is one having a ground state above the ground state of the sensitizer to provide a plentiful source of electrons to the dye during current generation and thereby enhance the generation; and the metal for the thin-film layer of metal is selected to have a Fermi level in the vicinity of or above the ground state of the reducing agent to thereby amply supply electrons to the reducing agent.

  6. Dye-sensitized solar cells

    DOE Patents [OSTI]

    Skotheim, T.A.

    1980-03-04

    A low-cost dye-sensitized Schottky barrier solar cell is comprised of a substrate of semiconductor with an ohmic contact on one face, a sensitizing dye adsorbed onto the opposite face of the semiconductor, a transparent thin-film layer of a reducing agent over the dye, and a thin-film layer of metal over the reducing agent. The ohmic contact and metal layer constitute electrodes for connection to an external circuit and one or the other or both are made transparent to permit light to penetrate to the dye and be absorbed therein for generating electric current. The semiconductor material chosen to be the substrate is one having a wide bandgap and which therefore is transparent; the dye selected is one having a ground state within the bandgap of the semiconductor to generate carriers in the semiconductor, and a first excited state above the conduction band edge of the semiconductor to readily conduct electrons from the dye to the semiconductor; the reducing agent selected is one having a ground state above the ground state of the sensitizer to provide a plentiful source of electrons to the dye during current generation and thereby enhance the generation; and the metal for the thin-film layer of metal is selected to have a Fermi level in the vicinity of or above the ground state of the reducing agent to thereby amply supply electrons to the reducing agent. 3 figs.

  7. Biomimetic Dye Molecules for Solar Cells

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

    traditional (polluting) energy sources. The most cost-effective solar cells are not high-end, high-efficiency ... what makes them so efficient, and how to mimic them ...

  8. Biomimetic Dye Molecules for Solar Cells

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

    must be identified and fixed before they can be incorporated for use in mass-produced solar cells. This research represents a first step towards establishing a feedback loop to...

  9. Biomimetic Dye Molecules for Solar Cells

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

    Though solar cells can use energy directly from the Sun to produce electricity that can be converted efficiently into other kinds of energy, they are currently too costly to ...

  10. Flipping crystals improves solar-cell performance

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

    Three types of large-area solar cells made out of two-dimensional perovskites. At left, a room-temperature cast film; upper middle is a sample with the problematic band gap, and at ...

  11. NREL Technique Leads to Improved Solar Cells

    Broader source: Energy.gov [DOE]

    Scientists at the Energy Department's National Renewable Energy Laboratory (NREL), in collaboration with researchers at Shanghai Jiao Tong University (SJTU), devised a method to improve perovskite solar cells, making them more efficient and reliable with higher reproducibility.

  12. New Solar Cells to Boost Satellite Power

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

    Solar Cells to Boost Satellite Power For more information contact: George Douglas (303) 275-4096 e:mail: georgedouglas@nrel.gov TECSTAR SIGNS PATENT AGREEMENT WITH NREL Golden, ...

  13. Hybrid Solar Cells via UV Polymerization of Polymer Precursor | Argonne

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

    National Laboratory Solar Cells via UV Polymerization of Polymer Precursor Technology available for licensing: A method to create improved hybrid solar cells through the ultraviolet (UV) polymerization of a polymer precursor. Creates high-performing hybrid solar cells through ultraviolet polymerization of a polymer precursor Cost effective, simple method PDF icon hybrid_solar_cells

  14. Nx-TEC: Next-Generation Thermionic Solar Energy Conversion | Department of

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

    Energy Nx-TEC: Next-Generation Thermionic Solar Energy Conversion Nx-TEC: Next-Generation Thermionic Solar Energy Conversion This presentation was delivered at the SunShot Concentrating Solar Power (CSP) Program Review 2013, held April 23-25, 2013 near Phoenix, Arizona. csp_review_meeting_042313_melosh.pdf (3.66 MB) More Documents & Publications Next-Generation Thermionic Solar Energy Conversion - FY13 Q2 Final Report - Technology Enabling Ultra High Concentration Multi-Junction Cells

  15. Nanoparticle Solar Cell Final Technical Report

    SciTech Connect (OSTI)

    Breeze, Alison, J; Sahoo, Yudhisthira; Reddy, Damoder; Sholin, Veronica; Carter, Sue

    2008-06-17

    The purpose of this work was to demonstrate all-inorganic nanoparticle-based solar cells with photovoltaic performance extending into the near-IR region of the solar spectrum as a pathway towards improving power conversion efficiencies. The field of all-inorganic nanoparticle-based solar cells is very new, with only one literature publication in the prior to our project. Very little is understood regarding how these devices function. Inorganic solar cells with IR performance have previously been fabricated using traditional methods such as physical vapor deposition and sputtering, and solution-processed devices utilizing IR-absorbing organic polymers have been investigated. The solution-based deposition of nanoparticles offers the potential of a low-cost manufacturing process combined with the ability to tune the chemical synthesis and material properties to control the device properties. This work, in collaboration with the Sue Carter research group at the University of California, Santa Cruz, has greatly expanded the knowledge base in this field, exploring multiple material systems and several key areas of device physics including temperature, bandgap and electrode device behavior dependence, material morphological behavior, and the role of buffer layers. One publication has been accepted to Solar Energy Materials and Solar Cells pending minor revision and another two papers are being written now. While device performance in the near-IR did not reach the level anticipated at the beginning of this grant, we did observe one of the highest near-IR efficiencies for a nanoparticle-based solar cell device to date. We also identified several key parameters of importance for improving both near-IR performance and nanoparticle solar cells in general, and demonstrated multiple pathways which showed promise for future commercialization with further research.

  16. Processing Iron Pyrite Nanocrystals for Use in Solar Cells - Energy

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

    Innovation Portal Solar Photovoltaic Solar Photovoltaic Find More Like This Return to Search Processing Iron Pyrite Nanocrystals for Use in Solar Cells Lawrence Berkeley National Laboratory Contact LBL About This Technology Technology Marketing SummaryFor solar energy to become an economically viable energy source, alternative semiconductor materials to be used in solar cells must be found. Silicon, the longtime standard for solar cells, is expensive to process and in ever-growing demand.

  17. Plastic Schottky-barrier solar cells

    DOE Patents [OSTI]

    Waldrop, J.R.; Cohen, M.J.

    1981-12-30

    A photovoltaic cell structure is fabricated from an active medium including an undoped polyacetylene, organic semiconductor. When a film of such material is in rectifying contact with a metallic area electrode, a Schottky-barrier junction is obtained within the body of the cell structure. Also, a gold overlayer passivates a magnesium layer on the undoped polyacetylene film. With the proper selection and location of elements a photovoltaic cell structure and solar cell are obtained.

  18. Third-Generation Solar Cells Using Optical Rectenna - Energy...

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

    The second generation of solar cells focuses on low production costs using thin film cells, which resulted in much lower efficiency rates. The third generation of solar cells has ...

  19. Method of restoring degraded solar cells

    DOE Patents [OSTI]

    Staebler, D.L.

    1983-02-01

    Amorphous silicon solar cells have been shown to have efficiencies which degrade as a result of long exposure to light. Annealing such cells in air at a temperature of about 200 C for at least 30 minutes restores their efficiency. 2 figs.

  20. Liquid cooled, linear focus solar cell receiver

    DOE Patents [OSTI]

    Kirpich, A.S.

    1983-12-08

    Separate structures for electrical insulation and thermal conduction are established within a liquid cooled, linear focus solar cell receiver for use with parabolic or Fresnel optical concentrators. The receiver includes a V-shaped aluminum extrusion having a pair of outer faces each formed with a channel receiving a string of solar cells in thermal contact with the extrusion. Each cell string is attached to a continuous glass cover secured within the channel with spring clips to isolate the string from the external environment. Repair or replacement of solar cells is effected simply by detaching the spring clips to remove the cover/cell assembly without interrupting circulation of coolant fluid through the receiver. The lower surface of the channel in thermal contact with the cells of the string is anodized to establish a suitable standoff voltage capability between the cells and the extrusion. Primary electrical insulation is provided by a dielectric tape disposed between the coolant tube and extrusion. Adjacent solar cells are soldered to interconnect members designed to accommodate thermal expansion and mismatches. The coolant tube is clamped into the extrusion channel with a releasably attachable clamping strip to facilitate easy removal of the receiver from the coolant circuit.

  1. Liquid cooled, linear focus solar cell receiver

    DOE Patents [OSTI]

    Kirpich, Aaron S.

    1985-01-01

    Separate structures for electrical insulation and thermal conduction are established within a liquid cooled, linear focus solar cell receiver for use with parabolic or Fresnel optical concentrators. The receiver includes a V-shaped aluminum extrusion having a pair of outer faces each formed with a channel receiving a string of solar cells in thermal contact with the extrusion. Each cell string is attached to a continuous glass cover secured within the channel with spring clips to isolate the string from the external environment. Repair or replacement of solar cells is effected simply by detaching the spring clips to remove the cover/cell assembly without interrupting circulation of coolant fluid through the receiver. The lower surface of the channel in thermal contact with the cells of the string is anodized to establish a suitable standoff voltage capability between the cells and the extrusion. Primary electrical insulation is provided by a dielectric tape disposed between the coolant tube and extrusion. Adjacent solar cells are soldered to interconnect members designed to accommodate thermal expansion and mismatches. The coolant tube is clamped into the extrusion channel with a releasably attachable clamping strip to facilitate easy removal of the receiver from the coolant circuit.

  2. Method of restoring degraded solar cells

    DOE Patents [OSTI]

    Staebler, David L.

    1983-01-01

    Amorphous silicon solar cells have been shown to have efficiencies which degrade as a result of long exposure to light. Annealing such cells in air at a temperature of about 200.degree. C. for at least 30 minutes restores their efficiency.

  3. NREL Scientists Report First Solar Cell Producing More Electrons In

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

    Photocurrent Than Solar Photons Entering Cell - News Releases | NREL Scientists Report First Solar Cell Producing More Electrons In Photocurrent Than Solar Photons Entering Cell December 15, 2011 Researchers from the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) have reported the first solar cell that produces a photocurrent that has an external quantum efficiency greater than 100 percent when photoexcited with photons from the high energy region of the solar

  4. Method of fabricating a solar cell array

    DOE Patents [OSTI]

    Lazzery, Angelo G.; Crouthamel, Marvin S.; Coyle, Peter J.

    1982-01-01

    A first set of pre-tabbed solar cells are assembled in a predetermined array with at least part of each tab facing upward, each tab being fixed to a bonding pad on one cell and abutting a bonding pad on an adjacent cell. The cells are held in place with a first vacuum support. The array is then inverted onto a second vacuum support which holds the tabs firmly against the cell pads they abut. The cells are exposed to radiation to melt and reflow the solder pads for bonding the tab portions not already fixed to bonding pads to these pads.

  5. The Kanatzidis - Chang Cell: dye sensitized all solid state solar...

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

    The Kanatzidis - Chang Cell: dye sensitized all solid state solar cell Home > Research > ANSER Research Highlights > The Kanatzidis - Chang Cell: dye sensitized all solid state ...

  6. Research on stable, high-efficiency amorphous silicon multijunction modules

    SciTech Connect (OSTI)

    Guha, S. )

    1991-12-01

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

  7. Amorphous silicon materials and solar cells

    SciTech Connect (OSTI)

    Stafford, B.L. )

    1991-01-01

    An International Meeting on Stability of Amorphous Silicon Materials and Solar Cells was held in Denver, CO on February 20--22, 1991. The main objectives of the meeting were to bring to light-and stimulate discussion on-recent advances in (1) understanding the underlying mechanisms of light-induced instability and (2) engineering approaches to stable solar cells. Several of the experimental and theoretical papers presented here, particularly those regarding low-hydrogen-content materials, give cause for optimism that the performance may finally be yielding to worldwide concerted efforts to understand and mitigate it. The four main topics discussed are modeling metastability, experimental data and model verification, materials studies, and solar cell studies.

  8. Fabricating solar cells with silicon nanoparticles

    SciTech Connect (OSTI)

    Loscutoff, Paul; Molesa, Steve; Kim, Taeseok

    2014-09-02

    A laser contact process is employed to form contact holes to emitters of a solar cell. Doped silicon nanoparticles are formed over a substrate of the solar cell. The surface of individual or clusters of silicon nanoparticles is coated with a nanoparticle passivation film. Contact holes to emitters of the solar cell are formed by impinging a laser beam on the passivated silicon nanoparticles. For example, the laser contact process may be a laser ablation process. In that case, the emitters may be formed by diffusing dopants from the silicon nanoparticles prior to forming the contact holes to the emitters. As another example, the laser contact process may be a laser melting process whereby portions of the silicon nanoparticles are melted to form the emitters and contact holes to the emitters.

  9. Method of manufacturing a solar cell panel

    SciTech Connect (OSTI)

    Dubois, P.

    1982-03-30

    The photovoltaic cells are retained and protected by a transparent elastomer layer extruded when hot prior to vulcanization and applied against the cells with a slight pressure to cause it to go into the spaces between cells, and vulcanized by heating, for example at 110* C. Or at 180* C., thanks to the presence of incorporated peroxides. Application in the production of electricity from solar energy.

  10. Solar cell contact formation using laser ablation

    DOE Patents [OSTI]

    Harley, Gabriel; Smith, David D.; Cousins, Peter John

    2014-07-22

    The formation of solar cell contacts using a laser is described. A method of fabricating a back-contact solar cell includes forming a poly-crystalline material layer above a single-crystalline substrate. The method also includes forming a dielectric material stack above the poly-crystalline material layer. The method also includes forming, by laser ablation, a plurality of contacts holes in the dielectric material stack, each of the contact holes exposing a portion of the poly-crystalline materiat layer; and forming conductive contacts in the plurality of contact holes.

  11. 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.

  12. 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.

  13. Solar cell contact formation using laser ablation

    DOE Patents [OSTI]

    Harley, Gabriel; Smith, David; Cousins, Peter

    2012-12-04

    The formation of solar cell contacts using a laser is described. A method of fabricating a back-contact solar cell includes forming a poly-crystalline material layer above a single-crystalline substrate. The method also includes forming a dielectric material stack above the poly-crystalline material layer. The method also includes forming, by laser ablation, a plurality of contacts holes in the dielectric material stack, each of the contact holes exposing a portion of the poly-crystalline material layer; and forming conductive contacts in the plurality of contact holes.

  14. Origami-enabled deformable silicon solar cells

    SciTech Connect (OSTI)

    Tang, Rui; Huang, Hai; Liang, Hanshuang; Liang, Mengbing; Tu, Hongen; Xu, Yong; Song, Zeming; Jiang, Hanqing; Yu, Hongyu

    2014-02-24

    Deformable electronics have found various applications and elastomeric materials have been widely used to reach flexibility and stretchability. In this Letter, we report an alternative approach to enable deformability through origami. In this approach, the deformability is achieved through folding and unfolding at the creases while the functional devices do not experience strain. We have demonstrated an example of origami-enabled silicon solar cells and showed that this solar cell can reach up to 644% areal compactness while maintaining reasonable good performance upon cyclic folding/unfolding. This approach opens an alternative direction of producing flexible, stretchable, and deformable electronics.

  15. Solar cell contact formation using laser ablation

    SciTech Connect (OSTI)

    Harley, Gabriel; Smith, David D.; Cousins, Peter John

    2015-07-21

    The formation of solar cell contacts using a laser is described. A method of fabricating a back-contact solar cell includes forming a poly-crystalline material layer above a single-crystalline substrate. The method also includes forming a dielectric material stack above the poly-crystalline material layer. The method also includes forming, by laser ablation, a plurality of contacts holes in the dielectric material stack, each of the contact holes exposing a portion of the poly-crystalline material layer; and forming conductive contacts in the plurality of contact holes.

  16. Development of high-bandgap AlGaInP solar cells grown by organometallic vapor-phase epitaxy

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

    Perl, Emmett E.; Simon, John; Geisz, John F.; Olavarria, Waldo; Young, Michelle; Duda, Anna; Friedman, Daniel J.; Steiner, Myles A.

    2016-03-29

    AlGaInP solar cells with bandgaps between 1.9 and 2.2 eV are investigated for use in next-generation multijunction photovoltaic devices. This quaternary alloy is of great importance to the development of III-V solar cells with five or more junctions and for cells optimized for operation at elevated temperatures because of the high bandgaps required in these designs. In this work, we explore the conditions for the organometallic vapor-phase epitaxy growth of AlGaInP and study their effects on cell performance. Initial efforts focused on developing ~2.0-eV AlGaInP solar cells with a nominal aluminum composition of 12%. Under the direct spectrum at 1000more » W/m2 (AM1.5D), the best of these samples had an open-circuit voltage of 1.59 V, a bandgap-voltage offset of 440 mV, a fill factor of 88.0%, and an efficiency of 14.8%. We then varied the aluminum composition of the alloy from 0% to 24% and were able to tune the bandgap of the AlGaInP layers from ~1.9 to ~2.2 eV. Furthermore, while the samples with a higher aluminum composition exhibited a reduced quantum efficiency and increased bandgap-voltage offset, the bandgap-voltage offset remained at 500 mV or less, up to a bandgap of ~2.1 eV.« less

  17. Award-Winning Etching Process Cuts Solar Cell Costs

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

    Award-Winning Etching Process Cuts Solar Cell Costs Optimizing solar-cell technology can be a complex job, requiring expertise in material science, physics, and optics to convert as much sunlight as possible into electricity. But despite this complexity, a simple fact is key to making a high-performance solar cell: any sunlight reflected off the cell can't possibly be converted into electricity. Manufacturers have tried to minimize the reflection of sunlight off of solar cells by first

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

    SciTech Connect (OSTI)

    Not Available

    2011-06-01

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

  19. 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.

  20. Final Report - High throughput CIGS solar cell fabrication via...

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

    High throughput CIGS solar cell fabrication via ultra-thin absorber layer with optical ... Contact Materials for Improved Performance CdTe Solar Cells Download the SunShot ...

  1. Konca Solar Cell Wuxi Co Ltd | Open Energy Information

    Open Energy Info (EERE)

    Konca Solar Cell Wuxi Co Ltd Jump to: navigation, search Name: Konca Solar Cell (Wuxi) Co Ltd Place: Wuxi, Jiangsu Province, China Product: China-based PV wafer manufacturer....

  2. Harmful Shunting Mechanisms Found in Silicon Solar Cells (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2011-05-01

    Scientists developed near-field optical microscopy for imaging electrical breakdown in solar cells and identified critical electrical breakdown mechanisms operating in industrial silicon and epitaxial silicon solar cells.

  3. Understanding Collection-Related Losses in Organic Solar Cells | ANSER

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

    Center | Argonne-Northwestern National Laboratory Understanding Collection-Related Losses in Organic Solar Cells Home > Research > ANSER Research Highlights > Understanding Collection-Related Losses in Organic Solar Cells

  4. When Function Follows Form: Plastic Solar Cells | ANSER Center |

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

    Argonne-Northwestern National Laboratory When Function Follows Form: Plastic Solar Cells Home > Research > ANSER Research Highlights > When Function Follows Form: Plastic Solar Cells

  5. 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 ... networks with sharp interfaces in order to produce high-efficiency devices. ...

  6. 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 Structure of All-Polymer Solar Cells Impedes ... networks with sharp interfaces in order to produce high-efficiency devices. ...

  7. A Supramolecular Complex in Small-Molecule Solar Cells based...

    Office of Scientific and Technical Information (OSTI)

    in Small-Molecule Solar Cells based on Contorted Aromatic Molecules Citation Details In-Document Search Title: A Supramolecular Complex in Small-Molecule Solar Cells based on ...

  8. Ohmic contacts for solar cells by arc plasma spraying

    DOE Patents [OSTI]

    Narasimhan, Mandayam C.; Roessler, Barton; Loferski, Joseph J.

    1982-01-01

    The method of applying ohmic contacts to a semiconductor, such as a silicon body or wafer used in solar cells, by the use of arc plasma spraying, and solar cells resulting therefrom.

  9. Ultra-Fast Quantum Efficiency Solar Cell Test - Energy Innovation...

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

    Ultra-Fast Quantum Efficiency Solar Cell Test National Renewable Energy Laboratory Contact NREL About This Technology Real-Time QE quickly measures how each solar cell responds to ...

  10. Research on stable, high-efficiency amorphous silicon multijunction modules. Annual subcontract report, 1 December 1991--31 October 1992

    SciTech Connect (OSTI)

    Ghosh, M.; DelCueto, J.: Kampas, F.; Xi, J.

    1993-02-01

    This report describes results from the first phase of a three-phase contract for the development of stable, high-efficiency, same-band-gap, amorphous silicon (a-Si) multijunction photovoltaic (PV) modules. The program involved improving the properties of individual layers of semiconductor and non-semiconductor materials and small-area single-junction and multijunction devices, as well as the multijunction modules. The semiconductor materials research was performed on a-Si p, i, and n layers, and on microcrystalline silicon n layers. These were deposited using plasma-enhanced chemical vapor deposition. The non-semiconductor materials studied were tin oxide, for use as a transparent-conducting-oxide (TCO), and zinc oxide, for use as a back reflector and as a buffer layer between the TCO and the semiconductor layers. Tin oxide was deposited using atmospheric-pressure chemical vapor deposition. Zinc oxide was deposited using magnetron sputtering. The research indicated that the major challenge in the fabrication of a-Si multijunction PV modules is the contact between the two p-i-n cells. A structure that has low optical absorption but that also facilitates the recombination of electrons from the first p-i-n structure with holes from the second p-i-n structure is required. Non-semiconductor layers and a-Si semiconductor layers were tested without achieving the desired result.

  11. Method of fabricating a solar cell

    DOE Patents [OSTI]

    Pass, Thomas; Rogers, Robert

    2014-02-25

    Methods of fabricating solar cells are described. A porous layer may be formed on a surface of a substrate, the porous layer including a plurality of particles and a plurality of voids. A solution may be dispensed into one or more regions of the porous layer to provide a patterned composite layer. The substrate may then be heated.

  12. Method of fabricating a solar cell

    DOE Patents [OSTI]

    Pass, Thomas; Rogers, Robert

    2016-02-16

    Methods of fabricating solar cells are described. A porous layer may be formed on a surface of a substrate, the porous layer including a plurality of particles and a plurality of voids. A solution may be dispensed into one or more regions of the porous layer to provide a patterned composite layer. The substrate may then be heated.

  13. Tandem junction amorphous silicon solar cells

    DOE Patents [OSTI]

    Hanak, Joseph J.

    1981-01-01

    An amorphous silicon solar cell has an active body with two or a series of layers of hydrogenated amorphous silicon arranged in a tandem stacked configuration with one optical path and electrically interconnected by a tunnel junction. The layers of hydrogenated amorphous silicon arranged in tandem configuration can have the same bandgap or differing bandgaps.

  14. Metal electrode for amorphous silicon solar cells

    DOE Patents [OSTI]

    Williams, Richard

    1983-01-01

    An amorphous silicon solar cell having an N-type region wherein the contact to the N-type region is composed of a material having a work function of about 3.7 electron volts or less. Suitable materials include strontium, barium and magnesium and rare earth metals such as gadolinium and yttrium.

  15. Plastic Schottky barrier solar cells

    DOE Patents [OSTI]

    Waldrop, James R.; Cohen, Marshall J.

    1984-01-24

    A photovoltaic cell structure is fabricated from an active medium including an undoped, intrinsically p-type organic semiconductor comprising polyacetylene. When a film of such material is in rectifying contact with a magnesium electrode, a Schottky-barrier junction is obtained within the body of the cell structure. Also, a gold overlayer passivates the magnesium layer on the undoped polyacetylene film.

  16. NREL Invention Speeds Solar Cell Quality Testing for Industry

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

    Invention Speeds Solar Cell Quality Testing for Industry A solid-state optical system, invented by the National Renewable Energy Laboratory (NREL), measures solar cell quantum efficiency (QE) in less than a second, enabling a suite of new capabilities for solar cell manufacturers. The system was developed with funding in part by the Office of Energy Efficiency and Renewable Energy within the U.S. Department of Energy. QE is a measurement of how cells respond to light across the solar spectrum,

  17. NREL Technique Leads to Improved Perovskite Solar Cells - News Releases |

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

    NREL NREL Technique Leads to Improved Perovskite Solar Cells August 1, 2016 Photo shows a man looking at a handful of solar cells made of perovskite. NREL researcher Mengjin Yang examines hybrid perovskite solar cells in his lab. (Photo by Dennis Schroeder / NREL) Scientists at the Energy Department's National Renewable Energy Laboratory (NREL), in collaboration with researchers at Shanghai Jiao Tong University (SJTU), devised a method to improve perovskite solar cells, making them more

  18. New Morphological Paradigm Uncovered in Organic Solar Cells

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

    New Morphological Paradigm Uncovered in Organic Solar Cells New Morphological Paradigm Uncovered in Organic Solar Cells Print Wednesday, 27 April 2011 00:00 Organic solar cells are made of light, flexible, renewable materials; they require simple and inexpensive processing steps and could produce an economically competitive and environmentally friendly energy source. Understanding the fundamentals of organic solar cell function is therefore vital to uncovering their maximum potential. Models

  19. Nanocluster production for solar cell applications

    SciTech Connect (OSTI)

    Al Dosari, Haila M.; Ayesh, Ahmad I.

    2013-08-07

    This research focuses on the fabrication and characterization of silver (Ag) and silicon (Si) nanoclusters that might be used for solar cell applications. Silver and silicon nanoclusters have been synthesized by means of dc magnetron sputtering and inert gas condensation inside an ultra-high vacuum compatible system. We have found that nanocluster size distributions can be tuned by various source parameters, such as the sputtering discharge power, flow rate of argon inert gas, and aggregation length. Quadrupole mass filter and transmission electron microscopy were used to evaluate the size distribution of Ag and Si nanoclusters. Ag nanoclusters with average size in the range of 3.68.3 nm were synthesized (herein size refers to the nanocluster diameter), whereas Si nanoclusters' average size was controlled to range between 2.9 and 7.4 nm by controlling the source parameters. This work illustrates the ability of controlling the Si and Ag nanoclusters' sizes by proper optimization of the operation conditions. By controlling nanoclusters' sizes, one can alter their surface properties to suit the need to enhance solar cell efficiency. Herein, Ag nanoclusters were deposited on commercial polycrystalline solar cells. Short circuit current (I{sub SC}), open circuit voltage (V{sub OC}), fill factor, and efficiency (?) were obtained under light source with an intensity of 30 mW/cm{sup 2}. A 22.7% enhancement in solar cell efficiency could be measured after deposition of Ag nanoclusters, which demonstrates that Ag nanoclusters generated in this work are useful to enhance solar cell efficiency.

  20. Diffraction: Enhanced Light Absorption of Solar Cells and Photodetectors -

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

    Energy Innovation Portal Solar Thermal Solar Thermal Solar Photovoltaic Solar Photovoltaic Advanced Materials Advanced Materials Find More Like This Return to Search Diffraction: Enhanced Light Absorption of Solar Cells and Photodetectors Sandia National Laboratories Contact SNL About This Technology Publications: PDF Document Publication Market Sheet (890 KB) Technology Marketing SummaryThe solar and photovoltaic industry has grown steadily over the last several years. In order to maintain

  1. Flexible thermal cycle test equipment for concentrator solar cells

    DOE Patents [OSTI]

    Hebert, Peter H.; Brandt, Randolph J.

    2012-06-19

    A system and method for performing thermal stress testing of photovoltaic solar cells is presented. The system and method allows rapid testing of photovoltaic solar cells under controllable thermal conditions. The system and method presents a means of rapidly applying thermal stresses to one or more photovoltaic solar cells in a consistent and repeatable manner.

  2. Method of fabricating a solar cell with a tunnel dielectric layer

    SciTech Connect (OSTI)

    Dennis, Tim; Harrington, Scott; Manning, Jane; Smith, David D.; Waldhauer, Ann

    2015-08-18

    Method of fabricating solar cells with tunnel dielectric layers are described. Solar cells with tunnel dielectric layers are also described.

  3. Method of fabricating a solar cell with a tunnel dielectric layer

    DOE Patents [OSTI]

    Dennis, Tim; Harrington, Scott; Manning, Jane; Smith, David D; Waldhauer, Ann

    2014-04-29

    Methods of fabricating solar cells with tunnel dielectric layers are described. Solar cells with tunnel dielectric layers are also described.

  4. Method of fabricating a solar cell with a tunnel dielectric layer

    DOE Patents [OSTI]

    Dennis, Tim; Harrington, Scott; Manning, Jane; Smith, David; Waldhauer, Ann

    2012-12-18

    Methods of fabricating solar cells with tunnel dielectric layers are described. Solar cells with tunnel dielectric layers are also described.

  5. The Kanatzidis - Chang Cell: dye sensitized all solid state solar cell |

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

    ANSER Center | Argonne-Northwestern National Laboratory The Kanatzidis - Chang Cell: dye sensitized all solid state solar cell Home > Research > ANSER Research Highlights > The Kanatzidis - Chang Cell: dye sensitized all solid state solar cell

  6. 2D Monolayers Could Yield Thinnest Solar Cells Ever

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

    Thinnest solar cells ever 2D Monolayers Could Yield Thinnest Solar Cells Ever October 21, 2013 Contact: Kathy Kincade, +1 510 495 2124, kkincade@lbl.gov Efforts to improve solar cells have historically focused on improving energy conversion efficiencies and lowering manufacturing costs. But new computer simulations have shown how using a different type of material could yield thinner, more lightweight solar panels that provide power densities - watts per kilogram of material - orders of

  7. Solar cell array panel and method of manufacture

    SciTech Connect (OSTI)

    Fraser, A. F.; Alsbach, W. G.

    1985-09-17

    An integral lightweight solar cell panel containing a plurality of interconnected solar cells bonded to a fiber-reinforced polyimide film made from an isoimide-containing precursor. The solar cells can be placed on the reinforced polyimide film while the film is in a partially cured condition and the cells become bonded to the film upon completion of the cure. A transparent polymeric film, such as a polyimide, can be used as protective means for the front surfaces of the cells.

  8. Research on stable, high-efficiency amorphous silicon multijunction modules. Final subcontract report, 1 January 1991--31 August 1994

    SciTech Connect (OSTI)

    Guha, S.

    1994-10-01

    The principal objective of this program is to conduct research on semiconductor materials and non-semiconductor materials to enhance the performance of multibandgap, multijunction, large-area amorphous silicon-based alloy modules. The goal for this program is to demonstrate stabilized module efficiency of 12% for multijunction modules of area greater than 900 cm{sup 2}. Double-junction and triple-junction cells are made on Ag/ZnO back reflector deposited on stainless steel substrates. The top cell uses a-Si alloy; a-SiGe alloy is used for the i layer in the middle and the bottom cells. After evaporation of antireflection coating, silver grids and bus bars are put on the top surface, and the panel is encapsulated in an ethylene vinyl acetate (EVA)/Tefzel structure to make a one-square-foot monolithic module.

  9. Modeling of Silicon Heterojunction Solar Cells

    SciTech Connect (OSTI)

    Luppina, P.; Lugli, P.; Goodnick, S.

    2015-06-14

    Here we present modeling results on crystalline Si/amorphous Si (a-Si) heterojunction solar cells using Sentaurus including various models for defect states in the a-Si barriers, as well as explicit models for the ITO emitter contact. We investigate the impact of the band offsets and barrier heights of the a-Si/c-Si interface, particularly in terms of the open circuit voltage. It is also shown that the solar cell performance is sensitively dependent on the quality of the a-Si in terms of defect states and their distribution, particularly on the emitter side. Finally, we have investigate the role of tunneling and thermionic emission across the heterointerface in terms of transport from the Si to the ITO contact layer

  10. Compensated amorphous-silicon solar cell

    DOE Patents [OSTI]

    Devaud, G.

    1982-06-21

    An amorphous silicon solar cell including an electrically conductive substrate, a layer of glow discharge deposited hydrogenated amorphous silicon having regions of differing conductivity with at least one region of intrinsic hydrogenated amorphous silicon. The layer of hydrogenated amorphous silicon has opposed first and second major surfaces where the first major surface contacts the elecrically conductive substrate and an electrode for electrically contacting the second major surface. The intrinsic hydrogenated amorphous silicon region is deposited in a glow discharge with an atmosphere which includes not less than about 0.02 atom percent mono-atomic boron. An improved N.I.P. solar cell is disclosed using a BF/sub 3/ doped intrinsic layer.

  11. Improved Performance of GaInNAs Solar Cells Grown by Molecular-Beam Epitaxy Using Increased Growth Rate Instead of Surfactants

    SciTech Connect (OSTI)

    Ptak, A. J.; France, R.; Jiang, C. S.; Romero, M. J.

    2009-01-01

    GaInNAs is potentially useful for increasing the conversion efficiency of multijunction solar cells if low photocurrents and photovoltages can be increased. Wide-depletion width devices generate significant photocurrents using an n-i-p structure grown by molecular-beam epitaxy, but these wide depletion widths are only realized in a region of parameter space that leads to rough surface morphologies. Surfactants are effective at reducing the surface roughness, but lead to increased defect densities and changes in the net acceptor or donor concentration. Here, we show that increasing the growth rate of GaInNAs solar cells leads to smooth surfaces without the use of a surfactant, even at high In compositions and substrate temperatures. No degradation in material quality is observed when increasing the growth rate from 1.5 to 3.0 {micro}m/h, but a shunt resistance does appear for the high-growth-rate samples. This shunt is attributed to increased spitting of the Ga cell, leading to an increase in the oval defect density, at the higher effusion cell temperatures used to achieve high growth rates. As with the case of Bi in GaInNAs, increased growth rates also appear to increase the net donor concentration, but it is not clear if these effects have the same cause.

  12. The Silicon Solar Cell Turns 50

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

    Daryl Chapin, Calvin Fuller, and Gerald Pearson likely never imagined inventing a solar ... Being a solar energy enthusiast, he suggested that the investi- gation include solar ...

  13. Composition for applying antireflective coating on solar cell

    SciTech Connect (OSTI)

    Whitehouse, D.L.

    1983-10-25

    A method is disclosed, and the composition, for the application of an antireflective coating on solar cells and the subsequent application of metal contacts comprising applying a screen to the surface of a solar cell, applying a paste comprising a metal alkoxide over the screen, heat treating the cell and metal alkoxide paste, and nickel plating the resultant cell.

  14. Method for applying antireflective coating on solar cell

    SciTech Connect (OSTI)

    Whitehouse, D.L.

    1982-05-04

    A method for the application and the composition of an antireflective coating on solar cells and the subsequent application of metal contacts comprises applying a screen to the surface of a solar cell, applying a paste comprising a metal alkoxide over the screen, heat treating the cell and metal alkoxide paste, and nickel plating the resultant cell.

  15. Solar Photovoltaic Cell/Module Shipments - Energy Information...

    Gasoline and Diesel Fuel Update (EIA)

    Solar Photovoltaic CellModule Shipments Report With data for 2014 | Release Date: July ... changes to strategic planning of companies in the U.S. solar photovoltaic (PV) industry. ...

  16. Student Winners Announced in Solar and Hydrogen Fuel Cell Car...

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

    Student Winners Announced in Solar and Hydrogen Fuel Cell Car Races May 21, 2011 Sixty-five teams from 24 Colorado schools participated in today's Junior Solar Sprint and Hydrogen ...

  17. New Solar Cell Is More Efficient, Less Costly - News Feature...

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

    New Solar Cell Is More Efficient, Less Costly November 8, 2013 In this photo, a researcher in glasses holds a solar wafer about the size of a CD case. In the background are two ...

  18. Inverted amorphous silicon solar cell utilizing cermet layers

    DOE Patents [OSTI]

    Hanak, Joseph J.

    1979-01-01

    An amorphous silicon solar cell incorporating a transparent high work function metal cermet incident to solar radiation and a thick film cermet contacting the amorphous silicon opposite to said incident surface.

  19. The reliability and stability of multijunction amorphous silicon PV modules

    SciTech Connect (OSTI)

    Carlson, D.E.

    1995-11-01

    Solarex is developing a manufacturing process for the commercial production of 8 ft{sup 2} multijunction amorphous silicon (a-Si) PV modules starting in 1996. The device structure used in these multijunction modules is: glass/textured tin oxide/p-i-n/p-i-n/ZnO/Al/EVA/Tedlar where the back junction of the tandem structure contains an amorphous silicon germanium alloy. As an interim step, 4 ft{sup 2} multijunction modules have been fabricated in a pilot production mode over the last several months. The distribution of initial conversion efficiencies for an engineering run of 67 modules (4 ft{sup 2}) is shown. Measurements recently performed at NREL indicate that the actual efficiencies are about 5% higher than those shown, and thus exhibit an average initial conversion efficiency of about 9.5%. The data indicates that the process is relatively robust since there were no modules with initial efficiencies less than 7.5%.

  20. Special section guest editorial: Hybrid organic-inorganic solar cells

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

    Nogueira, Ana Flavia; Rumbles, Garry

    2015-04-06

    In this special section of the Journal of Photonics for Energy, there is a focus on some of the science and technology of a range of different hybrid organic-inorganic solar cells. Prior to 1991 there were many significant scientific research reports of hybrid organic-inorganic solar cells; finally, however, it wasn’t until the dye-sensitized solar cell entered the league table of certified research cell efficiencies that this area experienced an explosion of research activity.

  1. Defect behavior of polycrystalline solar cell silicon

    SciTech Connect (OSTI)

    Schroder, D.K.; Park, S.H.; Hwang, I.G.; Mohr, J.B.; Hanly, M.P.

    1993-05-01

    The major objective of this study, conducted from October 1988 to September 1991, was to gain an understanding of the behavior of impurities in polycrystalline silicon and the influence of these impurities on solar cell efficiency. The authors studied edge-defined film-fed growth (EFG) and cast poly-Si materials and solar cells. With EFG Si they concentrated on chromium-doped materials and cells to determine the role of Cr on solar cell performance. Cast poly-Si samples were not deliberately contaminated. Samples were characterized by cell efficiency, current-voltage, deep-level transient spectroscopy (DLTS), surface photovoltage (SPV), open-circuit voltage decay, secondary ion mass spectrometry, and Fourier transform infrared spectroscopy measurements. They find that Cr forms Cr-B pairs with boron at room temperature and these pairs dissociate into Cr{sub i}{sup +} and B{sup {minus}} during anneals at 210{degrees}C for 10 min. Following the anneal, Cr-B pairs reform at room temperature with a time constant of 230 h. Chromium forms CrSi{sub 2} precipitates in heavily contaminated regions and they find evidence of CrSi{sub 2} gettering, but a lack of chromium segregation or precipitation to grain boundaries and dislocations. Cr-B pairs have well defined DLTS peaks. However, DLTS spectra of other defects are not well defined, giving broad peaks indicative of defects with a range of energy levels in the band gap. In some high-stress, low-efficiency cast poly-Si they detect SiC precipitates, but not in low-stress, high-efficiency samples. SPV measurements result in nonlinear SPV curves in some materials that are likely due to varying optical absorption coefficients due to locally varying stress in the material.

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

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

    Solar Photovoltaic Solar Photovoltaic Find More Like This Return to Search High Efficiency Multiple-Junction Solar Cells Sandia National Laboratories Contact SNL About This Technology Publications: PDF Document Publication Market Sheet (937 KB) Technology Marketing SummarySingle junction solar cells have limited efficiency and fail to extract maximum energy from photons outside of a specific spectral region. Higher efficiency and optical to electrical energy conversion is achieved by stacking

  3. Solar Junction Develops World Record Setting Concentrated Photovoltaic Solar Cell

    Broader source: Energy.gov [DOE]

    EERE supported the development of Solar Junction's concentrated photovoltaic technology that set a world record for conversion efficiency.

  4. TRANSPARENT COATINGS FOR SOLAR CELLS RESEARCH

    SciTech Connect (OSTI)

    Glatkowski, P.J.; Landis, D.A.

    2013-04-16

    Todays solar cells are fabricated using metal oxide based transparent conductive coatings (TCC) or metal wires with optoelectronic performance exceeding that currently possible with Carbon Nanotube (CNT) based TCCs. The motivation for replacing current TCC is their inherent brittleness, high deposition cost, and high deposition temperatures; leading to reduced performance on thin substrates. With improved processing, application and characterization techniques Nanofiber and/or CNT based TCCs can overcome these shortcomings while offering the ability to be applied in atmospheric conditions using low cost coating processes At todays level of development, CNT based TCC are nearing commercial use in touch screens, some types of information displays (i.e. electronic paper), and certain military applications. However, the resistivity and transparency requirements for use in current commercial solar cells are more stringent than in many of these applications. Therefore, significant research on fundamental nanotube composition, dispersion and deposition are required to reach the required performance commanded by photovoltaic devices. The objective of this project was to research and develop transparent conductive coatings based on novel nanomaterial composite coatings, which comprise nanotubes, nanofibers, and other nanostructured materials along with binder materials. One objective was to show that these new nanomaterials perform at an electrical resistivity and optical transparency suitable for use in solar cells and other energy-related applications. A second objective was to generate new structures and chemistries with improved resistivity and transparency performance. The materials also included the binders and surface treatments that facilitate the utility of the electrically conductive portion of these composites in solar photovoltaic devices. Performance enhancement venues included: CNT purification and metallic tube separation techniques, chemical doping, CNT

  5. Solar module having reflector between cells

    DOE Patents [OSTI]

    Kardauskas, Michael J.

    1999-01-01

    A photovoltaic module comprising an array of electrically interconnected photovoltaic cells disposed in a planar and mutually spaced relationship between a light-transparent front cover member in sheet form and a back sheet structure is provided with a novel light-reflecting means disposed between adjacent cells for reflecting light falling in the areas between cells back toward said transparent cover member for further internal reflection onto the solar cells. The light-reflecting comprises a flexible plastic film that has been embossed so as to have a plurality of small V-shaped grooves in its front surface, and a thin light-reflecting coating on said front surface, the portions of said coating along the sides of said grooves forming light-reflecting facets, said grooves being formed so that said facets will reflect light impinging thereon back into said transparent cover sheet with an angle of incidence greater than the critical angle, whereby substantially all of the reflected light will be internally reflected from said cover sheet back to said solar modules, thereby increasing the current output of the module.

  6. 'Nano'tubes, Surface Area & NanoSolar Cells

    K-12 Energy Lesson Plans and Activities Web site (EERE)

    This unit takes students through several introductory lessons designed to gain a better understanding of the 'nano' scale as it relates to the creation of a (dye-sensitized) solar cell (DSSC). The introductory lessons guide students through activities covering volume, surface area and density and exploration of the relationship between these factors. The unit culminates with students building a Gratzel cell, a solar cell employing a layer of nanospheres of TiO2 as the semiconductor and blackberry juice as the light absorber in a non-Si-based solar cell. Students are able to build a small solar cell and test its efficiency.

  7. Economical Pyrite-Based Solar Cells - Energy Innovation Portal

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

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

  8. Solare Cell Roof Tile And Method Of Forming Same

    DOE Patents [OSTI]

    Hanoka, Jack I. (Brookline, MA); Real, Markus (Oberberg, CH)

    1999-11-16

    A solar cell roof tile includes a front support layer, a transparent encapsulant layer, a plurality of interconnected solar cells and a backskin layer. The front support layer is formed of light transmitting material and has first and second surfaces. The transparent encapsulant layer is disposed adjacent the second surface of the front support layer. The interconnected solar cells has a first surface disposed adjacent the transparent encapsulant layer. The backskin layer has a first surface disposed adjacent a second surface of the interconnected solar cells, wherein a portion of the backskin layer wraps around and contacts the first surface of the front support layer to form the border region. A portion of the border region has an extended width. The solar cell roof tile may have stand-offs disposed on the extended width border region for providing vertical spacing with respect to an adjacent solar cell roof tile.

  9. Solar Cell Nanotechnology Final Technical Report

    SciTech Connect (OSTI)

    Das, Biswajit

    2014-05-07

    The objective of this project is to develop a low cost nonlithographic nanofabrication technology for the fabrication of thin film porous templates as well as uniform arrays of semiconductor nanostructures for the implementation of high efficiency solar cells. Solar cells based on semiconductor nanostructures are expected to have very high energy conversion efficiencies due to the increased absorption coefficients of semiconductor nanostructures. In addition, the thin film porous template can be used for optimum surface texturing of solar cells leading to additional enhancement in energy conversion efficiency. An important requirement for these applications is the ability to synthesize nanostructure arrays of different dimensions with good size control. This project employed nanoporous alumina templates created by the anodization of aluminum thin films deposited on glass substrates for the fabrication of the nanostructures and optimized the process parameters to obtain uniform pore diameters. An additional requirement is uniformity or regularity of the nanostructure arrays. While constant current anodization was observed to provide controlled pore diameters, constant voltage anodization was needed for regularity of the nanostructure arrays. Thus a two-step anodization process was investigated and developed in this project for improving the pore size distribution and pore periodicity of the nanoporous alumina templates. CdTe was selected to be the active material for the nanowires, and the process for the successful synthesis of CdTe nanowires was developed in this project. Two different synthesis approaches were investigated in this project, electrochemical and electrophoretic deposition. While electrochemical synthesis was successfully employed for the synthesis of nanowires inside the pores of the alumina templates, the technique was determined to be non-optimum due to the need of elevated temperature that is detrimental to the structural integrity of the

  10. Reducing the Cost of Solar Cells

    SciTech Connect (OSTI)

    Scanlon, B.

    2012-04-01

    Solar-powered electricity prices could soon approach those of power from coal or natural gas thanks to collaborative research with solar startup Ampulse Corporation at the National Renewable Energy Laboratory. Silicon wafers account for almost half the cost of today's solar photovoltaic panels, so reducing or eliminating wafer costs is essential to bringing prices down. Current crystalline silicon technology converts energy in a highly efficient manner; however, that technology is manufactured with processes that could stand some improvement. The industry needs a method that is less complex, creates less waste and uses less energy. First, half the refined silicon is lost as dust in the wafer-sawing process, driving module costs higher. Wafers are sawn off of large cylindrical ingots, or boules, of silicon. A typical 2-meter boule loses as many as 6,000 potential wafers during sawing. Second, the wafers produced are much thicker than necessary. To efficiently convert sunlight into electricity, the wafers need be only one-tenth the typical thickness. NREL, the Oak Ridge National Laboratory and Ampulse have partnered on an approach to eliminate this waste and dramatically lower the cost of the finished solar panels. By using a chemical vapor deposition process to grow the silicon on inexpensive foil, Ampulse is able to make the solar cells just thick enough to convert most of the solar energy into electricity. No more sawdust - and no more wasting refined silicon materials. NREL developed the technology to grow high-quality silicon and ORNL developed the metal foil that has the correct crystal structure to support that growth. Ampulse is installing a pilot manufacturing line in NREL's Process Development Integration Laboratory, where solar companies can work closely with lab scientists on integrated equipment to answer pressing questions related to their technology development, as well as rapidly overcoming R and D challenges and risk. NREL's program is focused on

  11. GaP/Si heterojunction Solar Cells

    SciTech Connect (OSTI)

    Saive, R.; Chen, C.; Emmer, H.; Atwater, H.

    2015-05-11

    Improving the efficiency of solar cells requires the introduction of novel device concepts. Recent developments have shown that in Si solar cell technology there is still room for tremendous improvement. Using the heterojunction with intrinsic thin layer (HIT) approach 25.6 % power conversion efficiency was achieved. However, a-Si as a window and passivation layer comes with disadvantages as a-Si shows low conductivity and high parasitic absorption. Therefore, it is likely that using a crystalline material as window layer with high band gab and high mobility can further improve efficiency. We have studied GaP grown by MOCVD on Si with (001) and (112) orientation. We obtained crystalline layers with carrier mobility around 100 cm2/Vs and which passivate Si as confirmed by carrier lifetime measurements. We performed band alignment studies by X-ray photoelectron spectroscopy yielding a valence band offset of 0.3 eV. Comparing this value with the Schottky-model leads to an interface dipole of 0.59 eV. The open circuit voltage increases with increasing doping and is consistent with the theoretical open circuit voltage deduced from work function difference and interface dipole. We obtain an open circuit voltage of 0.38 V for n-doped GaP with doping levels in the order of 10^17 1/cm^3. In our next steps we will increase the doping level further in order to gain higher open circuit voltage. We will discuss the implications of these findings for GaP/Si heterojunction solar cells.

  12. Cadmium telluride solar cells: Record-breaking voltages

    SciTech Connect (OSTI)

    Poplawsky, Jonathan D.

    2016-01-01

    Here, the performance of CdTe solar cells — cheaper alternatives to silicon photovoltaics — is hampered by their low output voltages, which are normally well below the theoretical limit. Now, record voltages of over 1 V have been reported in single-crystal CdTe heterostructure solar cells, which are close to those of benchmark GaAs cells.

  13. NREL, SLAC Scientists Pinpoint Solar Cell Manufacturing Process - News

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

    Releases | NREL NREL, SLAC Scientists Pinpoint Solar Cell Manufacturing Process April 1, 2016 Scientists at the Energy Department's National Renewable Energy Laboratory (NREL) and SLAC National Accelerator Laboratory have been able to pinpoint for the first time what happens during a key manufacturing process of silicon solar cells. Their paper, "The formation mechanism for printed silver-contacts for silicon solar cells," appears in the journal Nature Communications. The paper was

  14. New Morphological Paradigm Uncovered in Organic Solar Cells

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

    New Morphological Paradigm Uncovered in Organic Solar Cells Print Organic solar cells are made of light, flexible, renewable materials; they require simple and inexpensive processing steps and could produce an economically competitive and environmentally friendly energy source. Understanding the fundamentals of organic solar cell function is therefore vital to uncovering their maximum potential. Models describing critical device functions such as charge separation and transport often depend on

  15. New Morphological Paradigm Uncovered in Organic Solar Cells

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

    New Morphological Paradigm Uncovered in Organic Solar Cells Print Organic solar cells are made of light, flexible, renewable materials; they require simple and inexpensive processing steps and could produce an economically competitive and environmentally friendly energy source. Understanding the fundamentals of organic solar cell function is therefore vital to uncovering their maximum potential. Models describing critical device functions such as charge separation and transport often depend on

  16. New Morphological Paradigm Uncovered in Organic Solar Cells

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

    New Morphological Paradigm Uncovered in Organic Solar Cells Print Organic solar cells are made of light, flexible, renewable materials; they require simple and inexpensive processing steps and could produce an economically competitive and environmentally friendly energy source. Understanding the fundamentals of organic solar cell function is therefore vital to uncovering their maximum potential. Models describing critical device functions such as charge separation and transport often depend on

  17. New Morphological Paradigm Uncovered in Organic Solar Cells

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

    New Morphological Paradigm Uncovered in Organic Solar Cells Print Organic solar cells are made of light, flexible, renewable materials; they require simple and inexpensive processing steps and could produce an economically competitive and environmentally friendly energy source. Understanding the fundamentals of organic solar cell function is therefore vital to uncovering their maximum potential. Models describing critical device functions such as charge separation and transport often depend on

  18. Engineering Metal Impurities in Multicrystalline Silicon Solar Cells

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

    Engineering Metal Impurities in Multicrystalline Silicon Solar Cells Print Transition metals are one of the main culprits in degrading the efficiency of multicrystalline solar cells. With a suite of x-ray microprobe techniques, a multi-institutional collaboration led by researchers from the University of California, Berkeley, and Berkeley Lab studied the distribution of metal clusters in a variety of multicrystalline solar cells before and after processing. Their discovery that the size, spatial

  19. Engineering Metal Impurities in Multicrystalline Silicon Solar Cells

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

    Engineering Metal Impurities in Multicrystalline Silicon Solar Cells Print Transition metals are one of the main culprits in degrading the efficiency of multicrystalline solar cells. With a suite of x-ray microprobe techniques, a multi-institutional collaboration led by researchers from the University of California, Berkeley, and Berkeley Lab studied the distribution of metal clusters in a variety of multicrystalline solar cells before and after processing. Their discovery that the size, spatial

  20. Engineering Metal Impurities in Multicrystalline Silicon Solar Cells

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

    Engineering Metal Impurities in Multicrystalline Silicon Solar Cells Print Transition metals are one of the main culprits in degrading the efficiency of multicrystalline solar cells. With a suite of x-ray microprobe techniques, a multi-institutional collaboration led by researchers from the University of California, Berkeley, and Berkeley Lab studied the distribution of metal clusters in a variety of multicrystalline solar cells before and after processing. Their discovery that the size, spatial

  1. Engineering Metal Impurities in Multicrystalline Silicon Solar Cells

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

    Engineering Metal Impurities in Multicrystalline Silicon Solar Cells Print Transition metals are one of the main culprits in degrading the efficiency of multicrystalline solar cells. With a suite of x-ray microprobe techniques, a multi-institutional collaboration led by researchers from the University of California, Berkeley, and Berkeley Lab studied the distribution of metal clusters in a variety of multicrystalline solar cells before and after processing. Their discovery that the size, spatial

  2. Engineering Metal Impurities in Multicrystalline Silicon Solar Cells

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

    Engineering Metal Impurities in Multicrystalline Silicon Solar Cells Print Transition metals are one of the main culprits in degrading the efficiency of multicrystalline solar cells. With a suite of x-ray microprobe techniques, a multi-institutional collaboration led by researchers from the University of California, Berkeley, and Berkeley Lab studied the distribution of metal clusters in a variety of multicrystalline solar cells before and after processing. Their discovery that the size, spatial

  3. Engineering Metal Impurities in Multicrystalline Silicon Solar Cells

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

    Engineering Metal Impurities in Multicrystalline Silicon Solar Cells Print Transition metals are one of the main culprits in degrading the efficiency of multicrystalline solar cells. With a suite of x-ray microprobe techniques, a multi-institutional collaboration led by researchers from the University of California, Berkeley, and Berkeley Lab studied the distribution of metal clusters in a variety of multicrystalline solar cells before and after processing. Their discovery that the size, spatial

  4. Engineering Metal Impurities in Multicrystalline Silicon Solar Cells

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

    Engineering Metal Impurities in Multicrystalline Silicon Solar Cells Engineering Metal Impurities in Multicrystalline Silicon Solar Cells Print Wednesday, 26 October 2005 00:00 Transition metals are one of the main culprits in degrading the efficiency of multicrystalline solar cells. With a suite of x-ray microprobe techniques, a multi-institutional collaboration led by researchers from the University of California, Berkeley, and Berkeley Lab studied the distribution of metal clusters in a

  5. New Morphological Paradigm Uncovered in Organic Solar Cells

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

    New Morphological Paradigm Uncovered in Organic Solar Cells Print Organic solar cells are made of light, flexible, renewable materials; they require simple and inexpensive processing steps and could produce an economically competitive and environmentally friendly energy source. Understanding the fundamentals of organic solar cell function is therefore vital to uncovering their maximum potential. Models describing critical device functions such as charge separation and transport often depend on

  6. New Morphological Paradigm Uncovered in Organic Solar Cells

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

    New Morphological Paradigm Uncovered in Organic Solar Cells Print Organic solar cells are made of light, flexible, renewable materials; they require simple and inexpensive processing steps and could produce an economically competitive and environmentally friendly energy source. Understanding the fundamentals of organic solar cell function is therefore vital to uncovering their maximum potential. Models describing critical device functions such as charge separation and transport often depend on

  7. New Morphological Paradigm Uncovered in Organic Solar Cells

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

    New Morphological Paradigm Uncovered in Organic Solar Cells Print Organic solar cells are made of light, flexible, renewable materials; they require simple and inexpensive processing steps and could produce an economically competitive and environmentally friendly energy source. Understanding the fundamentals of organic solar cell function is therefore vital to uncovering their maximum potential. Models describing critical device functions such as charge separation and transport often depend on

  8. 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 Structure of All-Polymer Solar Cells Impedes Efficiency Print Wednesday, 27 October 2010 00:00 Organic solar cells are made of thin layers of interpenetrating structures from two different conducting organic materials and are increasingly popular because they are both potentially cheaper to make than those currently in use and can be "painted" or printed onto a variety of surfaces, including flexible films made from the same

  9. Hydrogenation of Dislocation-Limited Heteroepitaxial Silicon Solar Cells:

    Office of Scientific and Technical Information (OSTI)

    Preprint (Conference) | SciTech Connect Conference: Hydrogenation of Dislocation-Limited Heteroepitaxial Silicon Solar Cells: Preprint Citation Details In-Document Search Title: Hydrogenation of Dislocation-Limited Heteroepitaxial Silicon Solar Cells: Preprint Post-deposition hydrogenation by remote plasma significantly improves performance of heteroepitaxial silicon solar cells. Heteroepitaxial deposition of thin crystal silicon on sapphire for photovoltaics (PV) is an excellent model

  10. Intermediate Bandgap Solar Cells From Nanostructured Silicon

    SciTech Connect (OSTI)

    Black, Marcie

    2014-10-30

    This project aimed to demonstrate increased electronic coupling in silicon nanostructures relative to bulk silicon for the purpose of making high efficiency intermediate bandgap solar cells using silicon. To this end, we formed nanowires with controlled crystallographic orientation, small diameter, <111> sidewall faceting, and passivated surfaces to modify the electronic band structure in silicon by breaking down the symmetry of the crystal lattice. We grew and tested these silicon nanowires with <110>-growth axes, which is an orientation that should produce the coupling enhancement.

  11. Method of fabricating bifacial tandem solar cells

    DOE Patents [OSTI]

    Wojtczuk, Steven J; Chiu, Philip T; Zhang, Xuebing; Gagnon, Edward; Timmons, Michael

    2014-10-07

    A method of fabricating on a semiconductor substrate bifacial tandem solar cells with semiconductor subcells having a lower bandgap than the substrate bandgap on one side of the substrate and with subcells having a higher bandgap than the substrate on the other including, first, growing a lower bandgap subcell on one substrate side that uses only the same periodic table group V material in the dislocation-reducing grading layers and bottom subcells as is present in the substrate and after the initial growth is complete and then flipping the substrate and growing the higher bandgap subcells on the opposite substrate side which can be of different group V material.

  12. Research on stable, high-efficiency amorphous silicon multijunction modules. Semiannual subcontract report, 1 March 1993--30 November 1993

    SciTech Connect (OSTI)

    Guha, S.

    1994-03-01

    This report describes the progress made during the first half of Phase III of the R&D program to obtain high-efficiency amorphous silicon alloy multijunction modules. The highlight of the work includes (1) demonstration of the world`s highest initial module efficiency (area of 0.09 m{sup 2}) of 11.4% as confirmed by NREL, and (2) demonstration of stable module efficiency of 9.5% after 1-sun light soaking for 1000 h at 50{degrees}C. In addition, fundamental studies were carried out to improve material properties of the component cells of the multijunction structure and to understand the optical losses associated with the back reflector.

  13. Thinner Film Silicon Solar Cells - Energy Innovation Portal

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

    thin film silicon solar cells with a potential increase in photon energy conversion of up to 20%, a significant improvement over conventional thin film photovoltaic technologies. ...

  14. Low Cost, High Efficiency Tandem Silicon Solar Cells and LEDs...

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

    Building Energy Efficiency Building Energy ... Return to Search Low Cost, High Efficiency Tandem Silicon Solar Cells and LEDs ... gaps will lead to efficient power conversion. ...

  15. New Morphological Paradigm Uncovered in Organic Solar Cells

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

    layer. This improved understanding will guide the future development and optimization of organic solar cells by reducing laborious trial-and-error development and forcing other...

  16. New Morphological Paradigm Uncovered in Organic Solar Cells

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

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

  17. New Morphological Paradigm Uncovered in Organic Solar Cells

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

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

  18. NREL, SLAC Scientists Pinpoint Solar Cell Manufacturing Process...

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

    Laboratory (NREL) and SLAC National Accelerator Laboratory have been able to pinpoint for the first time what happens during a key manufacturing process of silicon solar cells. ...

  19. New Morphological Paradigm Uncovered in Organic Solar Cells

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

    Understanding the fundamentals of organic solar cell function is therefore vital to uncovering their maximum potential. Models describing critical device functions such as charge ...

  20. Organics Energize Solar Cell Research | Argonne Leadership Computing...

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

    energy we have only recently begun to harvest and convert into electricity. Today, most solar panel technologies rely on crystalline silicon photovoltaic cells. Despite their...

  1. 15.01.16 RH Perovskite Solar Cells - JCAP

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

    Fabrication of High Efficiency Perovskite Solar Cells Li, Y., Cooper, J. K., Buonsanti, R., Giannini, G., Liu, Y., Toma, F. M. & Sharp, I. D. Fabrication of Planar Heterojunction ...

  2. Hybrid Organic-Inorganic Halide Perovskite Solar Cells | Department...

    Energy Savers [EERE]

    remain before perovskite solar cells can become a competitive commercial technology. ... semiconductor applications, including thin-film transistors and light-emitting diodes, ...

  3. NREL Achieves World Record Performance For Thin Film Solar Cell...

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

    NREL Achieves World Record Performance For Thin Film Solar Cell Technology Golden, Colo., May 10, 1996 -- Scientists at the U. S. Department of Energy's National Renewable Energy ...

  4. Simple Method Quantifies Recombination Pathways in Solar Cells (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2013-09-01

    NREL's analytic equation uses open-circuit voltage data to determine how much recombination occurs via different channels in a solar cell.

  5. Techniques of Nanoscale Silicon Texturing of Solar Cells - Energy...

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

    Technology Marketing SummarySandia National Laboratories has created a technology that produces an antireflective (matte) surface on a silicon photovoltaic solar cell. The process ...

  6. NREL: News - Scientific American' Recognizes Solar Cell Research

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

    Scientific American' Recognizes Solar Cell Research Monday November 11, 2002 Magazine Names NREL to its First "Scientific American 50" List Golden, CO. - The U.S. Department of ...

  7. Alan J. Heeger, Conductive Polymers, and Plastic Solar Cells

    Office of Scientific and Technical Information (OSTI)

    Alan J. Heeger, Conductive Polymers, and Plastic Solar Cells Resources with Additional Information Patents Videos After receiving 'his physics Ph.D. at the University of...

  8. Process for Fabrication of Efficient Solar Cells - Energy Innovation...

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

    Process for Fabrication of Efficient Solar Cells Ames Laboratory Contact AMES About This ... Benefits 1. Efficient (improves light absorption and power conversion); 2. Economical (can ...

  9. Molecular beam epitaxy of ZnSSe/CdSe short-period superlattices for III–V/II–VI multijunction solar cells

    SciTech Connect (OSTI)

    Sorokin, S. V. Gronin, S. V.; Sedova, I. V.; Klimko, G. V.; Evropeitsev, E. A.; Baidakova, M. V.; Sitnikova, A. A.; Toropov, A. A.; Ivanov, S. V.

    2015-08-15

    Results on the molecular-beam epitaxy growth of short-period alternately-strained ZnS{sub x}Se{sub 1−x}/CdSe superlattices which are pseudomorphic to GaAs (001) substrates and possess effective band-gap values within the range of E{sub g} ≈ 2.5–2.7 eV are presented. Oscillations of the specular-spot intensity in reflection high-energy electron diffraction are used for in situ control of the superlattice parameters. A method to determine the SL parameters (compositions and thicknesses of the constituent layers) based on combined analysis of the grown structures by low-temperature photoluminescence and X-ray diffractometry is developed. It is found that the parameters of the grown ZnS{sub x}Se{sub 1−x}/CdSe superlattices are close to their design values and the density of extended defects in the structures is low even though the structure thickness (∼300 nm) considerably exceeds the critical thickness for bulk II–VI layers with the same lattice-constant mismatch.

  10. Performance model assessment for multi-junction concentrating photovoltaic systems.

    SciTech Connect (OSTI)

    Riley, Daniel M.; McConnell, Robert.; Sahm, Aaron; Crawford, Clark; King, David L.; Cameron, Christopher P.; Foresi, James S.

    2010-03-01

    Four approaches to modeling multi-junction concentrating photovoltaic system performance are assessed by comparing modeled performance to measured performance. Measured weather, irradiance, and system performance data were collected on two systems over a one month period. Residual analysis is used to assess the models and to identify opportunities for model improvement.

  11. Solar Cells Light Up Prison Cells on 'The Rock' - News Feature...

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

    Solar Cells Light Up Prison Cells on 'The Rock' July 23, 2012 This photo shows an island ... The 1,300 solar panels on the Cellhouse building are a dark blue. Enlarge image Alcatraz ...

  12. Laser processing technique for fabricating series-connected and tandem junction series-connected solar cells into a solar battery

    DOE Patents [OSTI]

    Hanak, Joseph J.

    1981-01-01

    A method of fabricating series-connected and tandem junction series-connected solar cells into a solar battery with laser scribing.

  13. 0.7-eV GaInAs Junction for a GaInP/GaAs/GaInAs(1eV)/GaInAs(0.7eV) Four-Junction Solar Cell

    SciTech Connect (OSTI)

    Friedman, D. J.; Geisz, J. F.; Norman, A. G.; Wanlass, M. W.; Kurtz, S. R.

    2006-01-01

    We discuss recent developments in III-V multijunction solar cells, focusing on adding a fourth junction to the Ga{sub 0.5}In{sub 0.5} P/GaAs/Ga{sub 0.75}In{sub 0.25}As inverted three-junction cell. This cell, grown inverted on GaAs so that the lattice-mismatched Ga{sub 0.75}In{sub 0.25}As third junction is the last one grown, has demonstrated 38% efficiency, and 40% is likely in the near future. To achieve still further gains, a lower-bandgap Ga{sub x}In{sub 1-x}As fourth junction could be added to the three-junction structure for a four-junction cell whose efficiency could exceed 45% under concentration. Here, we present the initial development of the Ga{sub x}In{sub 1-x}As fourth junction. Junctions of various bandgaps ranging from 0.88 to 0.73 eV were grown, in order to study the effect of the different amounts of lattice mismatch. At a bandgap of 0.88 eV, junctions were obtained with very encouraging {approx}80% quantum efficiency, 57% fill factor, and 0.36 eV open-circuit voltage. The device performance degrades with decreasing bandgap (i.e., increasing lattice mismatch). We model the four-junction device efficiency vs. fourth junction bandgap to show that an 0.7-eV fourth-junction bandgap, while optimal if it could be achieved in practice, is not necessary; an 0.9-eV bandgap would still permit significant gains in multijunction cell efficiency while being easier to achieve than the lower-bandgap junction.

  14. Laser beam apparatus and method for analyzing solar cells

    DOE Patents [OSTI]

    Staebler, David L.

    1980-01-01

    A laser beam apparatus and method for analyzing, inter alia, the current versus voltage curve at the point of illumination on a solar cell and the open circuit voltage of a solar cell. The apparatus incorporates a lock-in amplifier, and a laser beam light chopper which permits the measurement of the AC current of the solar cell at an applied DC voltage at the position on the solar cell where the cell is illuminated and a feedback scheme which permits the direct scanning measurements of the open circuit voltage. The accuracy of the measurement is a function of the intensity and wavelength of the laser light with respect to the intensity and wavelength distribution of sunlight and the percentage the dark current is at the open circuit voltage to the short circuit current of the solar cell.

  15. Perovskite solar cells self-heal in the dark

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

    Perovskite solar cells self-heal Perovskite solar cells self-heal in the dark Build-up of unwanted charge found to sap photocurrent May 17, 2016 perovskite team From left, Los Alamos researchers Aditya Mohite, Jean-Christophe Blancon and Wanyi Nie study both the cause and a solution for the tendency of perovskite solar cells to degrade in sunlight. Cooling, time in the dark preserve perovskite solar power A new study has found both the cause and a solution for the pesky tendency of perovskite

  16. Shiny quantum dots brighten future of solar cells

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

    Shiny quantum dots brighten future of solar cells Shiny quantum dots brighten future of solar cells The project demonstrates that superior light-emitting properties of quantum dots can be applied in solar energy by helping more efficiently harvest sunlight. April 14, 2014 Quantum dot LSC devices under ultraviolet illumination. Quantum dot LSC devices under ultraviolet illumination. Contact Nancy Ambrosiano Communications Office (505) 667-0471 Email "The key accomplishment is the

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

    SciTech Connect (OSTI)

    Ager, Joel W

    2011-02-14

    TCF funding of a CRADA between LBNL and RSLE leveraged RSLE's original $1M investment in LBNL research and led to development of a solar cell fabrication process that will bring the high efficiency, high voltage hybrid tandem solar cell closer to commercialization. RSLE has already built a pilot line at its Phoenix, Arizona site.

  18. Analytical determination of critical crack size in solar cells

    SciTech Connect (OSTI)

    Chen, C.P.

    1988-05-01

    Although solar cells usually have chips and cracks, no material specifications concerning the allowable crack size on solar cells are available for quality assurance and engineering design usage. Any material specifications that the cell manufacturers use were developed for cosmetic reasons that have no technical basis. Therefore, the Applied Solar Energy Corporation (ASEC) has sponsored a continuing program for the fracture mechanics evaluation of GaAs. Fracture mechanics concepts were utilized to develop an analytical model that can predict the critical crack size of solar cells. This model indicates that the edge cracks of a solar cell are more critical than its surface cracks. In addition, the model suggests that the material specifications on the allowable crack size used for Si solar cells should not be applied to GaAs solar cells. The analytical model was applied to Si and GaAs solar cells, but it would also be applicable to the semiconductor wafers of other materials, such as a GaAs thin film on a Ge substrate, using appropriate input data.

  19. In Situ X-Ray Scattering Helps Optimize Printed Solar Cells

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

    In Situ X-Ray Scattering Helps Optimize Printed Solar Cells In Situ X-Ray Scattering Helps Optimize Printed Solar Cells Print Wednesday, 25 February 2015 00:00 Plastic solar cells...

  20. World-Record Solar Cell a Step Closer to Cheap Solar Energy

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

    World-Record Solar Cell a Step Closer to Cheap Solar Energy For more information contact: George Douglas (303) 275-4096 e:mail: george_douglas@nrel.gov Golden, Colo., Feb. 25, 1999 — Researchers at the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) recently took another step toward reduced costs and increased competitiveness for solar energy by setting a world record for thin-film solar cell efficiency. The measurement of 18.8 percent efficiency for the copper indium

  1. Efficiency of silicon solar cells containing chromium

    DOE Patents [OSTI]

    Frosch, Robert A. Administrator of the National Aeronautics and Space; Salama, Amal M.

    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.

  2. Solar cells incorporating light harvesting arrays

    DOE Patents [OSTI]

    Lindsey, Jonathan S.; Meyer, Gerald J.

    2003-07-22

    A solar cell incorporates a light harvesting array that comprises: (a) a first substrate comprising a first electrode; and (b) a layer of light harvesting rods electrically coupled to the first electrode, each of the light harvesting rods comprising a polymer of Formula I: ##EQU1## wherein m is at least 1, and may be from two, three or four to 20 or more; X.sup.1 is a charge separation group (and preferably a porphyrinic macrocycle, which may be one ligand of a double-decker sandwich compound) having an excited-state of energy equal to or lower than that of X.sup.2 ; and X.sup.2 through X.sup.m+1 are chromophores (and again are preferably porphyrinic macrocycles).

  3. Solar cells incorporating light harvesting arrays

    DOE Patents [OSTI]

    Lindsey, Jonathan S.; Meyer, Gerald J.

    2002-01-01

    A solar cell incorporates a light harvesting array that comprises: (a) a first substrate comprising a first electrode; and (b) a layer of light harvesting rods electrically coupled to the first electrode, each of the light harvesting rods comprising a polymer of Formula I: X.sup.1.paren open-st.X.sup.m+1).sub.m (I) wherein m is at least 1, and may be from two, three or four to 20 or more; X.sup.1 is a charge separation group (and preferably a porphyrinic macrocycle, which may be one ligand of a double-decker sandwich compound) having an excited-state of energy equal to or lower than that of X.sup.2 ; and X.sup.2 through X.sup.m+1 are chromophores (and again are preferably porphyrinic macrocycles).

  4. Special section guest editorial: Hybrid organic-inorganic solar cells

    SciTech Connect (OSTI)

    Nogueira, Ana Flavia; Rumbles, Garry

    2015-04-06

    In this special section of the Journal of Photonics for Energy, there is a focus on some of the science and technology of a range of different hybrid organic-inorganic solar cells. Prior to 1991 there were many significant scientific research reports of hybrid organic-inorganic solar cells; finally, however, it wasn’t until the dye-sensitized solar cell entered the league table of certified research cell efficiencies that this area experienced an explosion of research activity.

  5. High-Efficiency, Commercial Ready CdTe Solar Cells

    SciTech Connect (OSTI)

    Sites, James R.

    2015-11-19

    Colorado State’s F-PACE project explored several ways to increase the efficiency of CdTe solar cells and to better understand the device physics of those cells under study. Increases in voltage, current, and fill factor resulted in efficiencies above 17%. The three project tasks and additional studies are described in detail in the final report. Most cells studied were fabricated at Colorado State using an industry-compatible single-vacuum closed-space-sublimation (CSS) chamber for deposition of the key semiconductor layers. Additionally, some cells were supplied by First Solar for comparison purposes, and a small number of modules were supplied by Abound Solar.

  6. Analysis of bias voltage dependent spectral response in Ga{sub 0.51}In{sub 0.49}P/Ga{sub 0.99}In{sub 0.01}As/Ge triple junction solar cell

    SciTech Connect (OSTI)

    Sogabe, Tomah Ogura, Akio; Okada, Yoshitaka

    2014-02-21

    Spectral response measurement plays great role in characterizing solar cell device because it directly reflects the efficiency by which the device converts the sunlight into an electrical current. Based on the spectral response results, the short circuit current of each subcell can be quantitatively determined. Although spectral response dependence on wavelength, i.e., the well-known external quantum efficiency (EQE), has been widely used in characterizing multijunction solar cell and has been well interpreted, detailed analysis of spectral response dependence on bias voltage (SR ?V{sub bias}) has not been reported so far. In this work, we have performed experimental and numerical studies on the SR??V{sub bias} for Ga{sub 0.51}In{sub 0.49}P/Ga{sub 0.99}In{sub 0.01}As/Ge triple junction solar cell. Phenomenological description was given to clarify the mechanism of operation matching point variation in SR??V{sub bias} measurements. The profile of SR?V{sub bias} curve was explained in detail by solving the coupled two-diode current-voltage characteristic transcend formula for each subcell.

  7. Taking on the Heat in Solar Cells: New Calculations Show Atomic...

    Office of Science (SC) Website

    Taking on the Heat in Solar Cells: New Calculations Show Atomic Vibrations Hurt Efficiency Theoretical modeling of energy loss in solar cells may lead to more efficient materials ...

  8. ANSER Center Chemists Design a First-of-its-Kind Solar Cell Experiment...

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

    Chemistry Students Home > News & Events > ANSER Chemists Design First Solar Cell Lab for Gen Chem Students ANSER Center Chemists Design First Solar Cell Lab for General Chemistry ...

  9. Problem Turned Into Performance for Solar Cells | U.S. DOE Office...

    Office of Science (SC) Website

    Problem Turned Into Performance for Solar Cells Basic Energy Sciences (BES) BES Home About ... Problem Turned Into Performance for Solar Cells Boundaries between crystalline grains - ...

  10. Process development for high-efficiency silicon solar cells

    SciTech Connect (OSTI)

    Gee, J.M.; Basore, P.A.; Buck, M.E.; Ruby, D.S.; Schubert, W.K.; Silva, B.L.; Tingley, J.W.

    1991-01-01

    Fabrication of high-efficiency silicon solar cells in an industrial environment requires a different optimization than in a laboratory environment. Strategies are presented for process development of high-efficiency silicon solar cells, with a goal of simplifying technology transfer into an industrial setting. The strategies emphasize the use of statistical experimental design for process optimization, and the use of baseline processes and cells for process monitoring and quality control. 8 refs.

  11. Effects of angular confinement and concentration to realistic solar cells

    SciTech Connect (OSTI)

    Höhn, O. Kraus, T.; Bläsi, B.; Schwarz, U. T.

    2015-01-21

    In standard solar cells, light impinges under a very small angular range, whereas the solar cell emits light into the whole half space. Due to this expansion of etendué, entropy is generated, which limits the maximal efficiency of solar cells. This limit can be overcome by either increasing the angle of incidence by concentration or by decreasing the angle of emission by an angularly confining element or by a combination of both. In an ideal solar cell with radiative recombination as the only loss mechanism, angular confinement and concentration are thermodynamically equivalent. It is shown that concentration in a device, where non-radiative losses such as Shockley-Read-Hall and Auger recombination are considered, is not equivalent to angular confinement. As soon as non-radiative losses are considered, the gain in efficiency due to angular confinement drops significantly in contrast to the gain caused by concentration. With the help of detailed balance calculations, it is furthermore shown that angular confinement can help to increase the efficiency of solar cells under concentrated sunlight even if no measurable gain is expected for the solar cell under 1-sun-illumination. Our analysis predicts a relative gain of 3.14% relative in efficiency for a realistic solar cell with a concentration factor of 500.

  12. Cost-Effective Replacement for Iodide in Dye-Sensitized Solar Cells -

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

    Energy Innovation Portal Solar Photovoltaic Solar Photovoltaic Find More Like This Return to Search Cost-Effective Replacement for Iodide in Dye-Sensitized Solar Cells Colorado State University Contact CSU About This Technology Publications: PDF Document Publication Electron Transfer Mediator Summary (236 KB) Cross-section of solar cell Cross-section of solar cell Technology Marketing SummaryDye-sensitized solar cells (DSSCs) are used to create electrical energy from sunlight. The cell has

  13. Accelerated aging of GaAs concentrator solar cells

    SciTech Connect (OSTI)

    Gregory, P.E.

    1982-04-01

    An accelerated aging study of AlGaAs/GaAs solar cells has been completed. The purpose of the study was to identify the possible degradation mechanisms of AlGaAs/GaAs solar cells in terrestrial applications. Thermal storage tests and accelerated AlGaAs corrosion studies were performed to provide an experimental basis for a statistical analysis of the estimated lifetime. Results of this study suggest that a properly designed and fabricated AlGaAs/GaAs solar cell can be mechanically rugged and environmentally stable with projected lifetimes exceeding 100 years.

  14. Air stable organic-inorganic nanoparticles hybrid solar cells

    DOE Patents [OSTI]

    Qian, Lei; Yang, Jihua; Xue, Jiangeng; Holloway, Paul H.

    2015-09-29

    A solar cell includes a low work function cathode, an active layer of an organic-inorganic nanoparticle composite, a ZnO nanoparticle layer situated between and physically contacting the cathode and active layers; and a transparent high work function anode that is a bilayer electrode. The inclusion of the ZnO nanoparticle layer results in a solar cell displaying a conversion efficiency increase and reduces the device degradation rate. Embodiments of the invention are directed to novel ZnO nanoparticles that are advantageous for use as the ZnO nanoparticle layers of the novel solar cells and a method to prepare the ZnO nanoparticles.

  15. Method for forming indium oxide/n-silicon heterojunction solar cells

    DOE Patents [OSTI]

    Feng, Tom; Ghosh, Amal K.

    1984-03-13

    A high photo-conversion efficiency indium oxide/n-silicon heterojunction solar cell is spray deposited from a solution containing indium trichloride. The solar cell exhibits an Air Mass One solar conversion efficiency in excess of about 10%.

  16. Dye-sensitized Schottky barrier solar cells

    DOE Patents [OSTI]

    Skotheim, Terje A.

    1978-01-01

    A low-cost dye-sensitized Schottky barrier solar cell comprised of a substrate of semiconductor with an ohmic contact on one face, a sensitizing dye adsorbed onto the opposite face of the semiconductor, a transparent thin-film layer of a reducing agent over the dye, and a thin-film layer of metal over the reducing agent. The ohmic contact and metal layer constitute electrodes for connection to an external circuit and one or the other or both are made transparent to permit light to penetrate to the dye and be absorbed therein for generating electric current. The semiconductor material chosen to be the substrate is one having a wide bandgap and which therefore is transparent; the dye selected is one having a ground state within the bandgap of the semiconductor to generate carriers in the semiconductor, and a first excited state above the conduction band edge of the semiconductor to readily conduct electrons from the dye to the semiconductor; the reducing agent selected is one having a ground state above the ground state of the sensitizer to provide a plentiful source of electrons to the dye during current generation and thereby enhance the generation; and the metal for the thin-film layer of metal is selected to have a Fermi level in the vicinity of or above the ground state of the reducing agent to thereby amply supply electrons to the reducing agent.

  17. Investigation of the texture surface silicon solar cell

    SciTech Connect (OSTI)

    Rongqiang, C.; Huilan, Q.

    1983-10-01

    The optical and electrical properties of the texture surface silicon solar cell are analyzed and discussed. A new method of etching a texture surface by LiOH is presented and the mechanism of etching a texture surface is investigated.

  18. NREL, SLAC Scientists Pinpoint Solar Cell Manufacturing Process

    Broader source: Energy.gov [DOE]

    Scientists at the Energy Department's National Renewable Energy Laboratory (NREL) and SLAC National Accelerator Laboratory have been able to pinpoint for the first time what happens during a key manufacturing process of silicon solar cells.

  19. Enhanced light absorption of solar cells and photodetectors by diffraction

    DOE Patents [OSTI]

    Zaidi, Saleem H.; Gee, James M.

    2005-02-22

    Enhanced light absorption of solar cells and photodetectors by diffraction is described. Triangular, rectangular, and blazed subwavelength periodic structures are shown to improve performance of solar cells. Surface reflection can be tailored for either broadband, or narrow-band spectral absorption. Enhanced absorption is achieved by efficient optical coupling into obliquely propagating transmitted diffraction orders. Subwavelength one-dimensional structures are designed for polarization-dependent, wavelength-selective absorption in solar cells and photodetectors, while two-dimensional structures are designed for polarization-independent, wavelength-selective absorption therein. Suitable one and two-dimensional subwavelength periodic structures can also be designed for broadband spectral absorption in solar cells and photodetectors. If reactive ion etching (RIE) processes are used to form the grating, RIE-induced surface damage in subwavelength structures can be repaired by forming junctions using ion implantation methods. RIE-induced surface damage can also be removed by post RIE wet-chemical etching treatments.

  20. Post-Deposition Treatment Boosts CIGS Solar Cell Performance...

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

    These experiments led to a 16.2%-efficient solar cell fabricated from the CuGa In stacked metal precursor. But the goal was to increase the efficiency and decrease the time ...

  1. Simple Method Quantifies Recombination Pathways in Solar Cells...

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

    NREL's analytic equation uses open-circuit voltage data to determine how much recombination occurs via different channels in a solar cell. Shockley-Reed-Hall recombination plays an ...

  2. Structure of All-Polymer Solar Cells Impedes Efficiency

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

    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 clean-energy...

  3. Approaches to Future Generation Photovoltaics and Solar Fuels: Quantum Dots, Arrays, and Quantum Dot Solar Cells

    SciTech Connect (OSTI)

    Semonin, O.; Luther, J.; Beard, M.; Johnson, J.; Gao, J.; Nozik, A.

    2012-01-01

    One potential, long-term approach to more efficient and lower cost future generation solar cells for solar electricity and solar fuels is to utilize the unique properties of quantum dots (QDs) to control the relaxation pathways of excited states to enhance multiple exciton generation (MEG). We have studied MEG in close-packed PbSe QD arrays where the QDs are electronically coupled in the films and thus exhibit good transport while still maintaining quantization and MEG. We have developed simple, all-inorganic solution-processable QD solar cells that produce large short-circuit photocurrents and power conversion efficiencies above 5% via nanocrystalline p-n junctions. These solar cells show QYs for photocurrent that exceed 100% in the photon energy regions where MEG is possible; the photocurrent MEG QYs as a function of photon energy match those determined via time-resolved spectroscopy Recent analyses of the major effect of MEG combined with solar concentration on the conversion efficiency of solar cells will also be discussed.

  4. NREL Theorizes Defects Could Improve Solar Cells - News Releases | NREL

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

    NREL Theorizes Defects Could Improve Solar Cells January 12, 2016 Drawing of of a good defect. Schematic of a 'good' defect (red cross), which helps collection of electrons from photo-absorber (n-Si), and blocks the holes, hence suppresses carriers recombination. Scientists at the Energy Department's National Renewable Energy Laboratory (NREL) are studying what may seem paradoxical - certain defects in silicon solar cells may actually improve their performance. The findings run counter to

  5. Laser processing of solar cells with anti-reflective coating

    DOE Patents [OSTI]

    Harley, Gabriel; Smith, David D.; Dennis, Tim; Waldhauer, Ann; Kim, Taeseok; Cousins, Peter John

    2016-02-16

    Contact holes of solar cells are formed by laser ablation to accommodate various solar cell designs. Use of a laser to form the contact holes is facilitated by replacing films formed on the diffusion regions with a film that has substantially uniform thickness. Contact holes may be formed to deep diffusion regions to increase the laser ablation process margins. The laser configuration may be tailored to form contact holes through dielectric films of varying thicknesses.

  6. 08.30.16 Stable Planar Solar Cells - JCAP

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

    Defective TiO2 with high photoconductive gain for efficient and stable planar heterojunction perovskite solar cells Li, Y. et al. Defective TiO2 with high photoconductive gain for efficient and stable planar heterojunction perovskite solar cells. Nature Communications, 7, 12446, DOI: 10.1038/ncomms12446 (2016). Defects in TiO2 electron selective contacts to halide perovskite light absorbers are engineered to beneficially reduce photocatalytic degradation and enable a high photoconductive gain.

  7. 15.01.16 RH Perovskite Solar Cells - JCAP

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

    Fabrication of High Efficiency Perovskite Solar Cells Li, Y., Cooper, J. K., Buonsanti, R., Giannini, G., Liu, Y., Toma, F. M. & Sharp, I. D. Fabrication of Planar Heterojunction Perovskite Solar Cells by Controlled Low-Pressure Vapor Annealing. J. Phys. Chem. Lett ., 6, 493-499, DOI: 10.1021/jz502720a (2015). Scientific Achievement A new synthetic method based on low-pressure and reduced-temperature vapor annealing was developed and demonstrated to yield efficient hybrid halide perovskites

  8. 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 materials and are increasingly popular because they are both potentially cheaper to make than those currently in use and can be "painted" or printed onto a variety of surfaces, including flexible films made from the same material as most soda bottles. A large community is exploring a number of promising material

  9. 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 materials and are increasingly popular because they are both potentially cheaper to make than those currently in use and can be "painted" or printed onto a variety of surfaces, including flexible films made from the same material as most soda bottles. A large community is exploring a number of promising material

  10. 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 materials and are increasingly popular because they are both potentially cheaper to make than those currently in use and can be "painted" or printed onto a variety of surfaces, including flexible films made from the same material as most soda bottles. A large community is exploring a number of promising material

  11. 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 materials and are increasingly popular because they are both potentially cheaper to make than those currently in use and can be "painted" or printed onto a variety of surfaces, including flexible films made from the same material as most soda bottles. A large community is exploring a number of promising material

  12. 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 materials and are increasingly popular because they are both potentially cheaper to make than those currently in use and can be "painted" or printed onto a variety of surfaces, including flexible films made from the same material as most soda bottles. A large community is exploring a number of promising material

  13. 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 materials and are increasingly popular because they are both potentially cheaper to make than those currently in use and can be "painted" or printed onto a variety of surfaces, including flexible films made from the same material as most soda bottles. A large community is exploring a number of promising material

  14. 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 materials and are increasingly popular because they are both potentially cheaper to make than those currently in use and can be "painted" or printed onto a variety of surfaces, including flexible films made from the same material as most soda bottles. A large community is exploring a number of promising material

  15. 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 materials and are increasingly popular because they are both potentially cheaper to make than those currently in use and can be "painted" or printed onto a variety of surfaces, including flexible films made from the same material as most soda bottles. A large community is exploring a number of promising material

  16. 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 materials and are increasingly popular because they are both potentially cheaper to make than those currently in use and can be "painted" or printed onto a variety of surfaces, including flexible films made from the same material as most soda bottles. A large community is exploring a number of promising material

  17. NREL Studies Carrier Separation and Transport in Perovskite Solar Cells

    SciTech Connect (OSTI)

    2016-01-01

    NREL scientists studied charge separation and transport in perovskite solar cells by determining the junction structure across the solar device using the nanoelectrical characterization technique of Kelvin probe force microscopy. The distribution of electrical potential across both planar and porous devices demonstrates a p-n junction structure at the interface between titanium dioxide and perovskite. In addition, minority-carrier transport within the devices operates under diffusion/drift. Clarifying the fundamental junction structure provides significant guidance for future research and development. This NREL study points to the fact that improving carrier mobility is a critical factor for continued efficiency gains in perovskite solar cells.

  18. Intermediate band solar cells: Recent progress and future directions

    SciTech Connect (OSTI)

    Okada, Y. Tamaki, R.; Farrell, D. J.; Yoshida, K.; Ahsan, N.; Shoji, Y.; Sogabe, T.; Ekins-Daukes, N. J. Yoshida, M.; Pusch, A.; Hess, O.; Phillips, C. C.; Kita, T.; Guillemoles, J.-F.

    2015-06-15

    Extensive literature and publications on intermediate band solar cells (IBSCs) are reviewed. A detailed discussion is given on the thermodynamics of solar energy conversion in IBSCs, the device physics, and the carrier dynamics processes with a particular emphasis on the two-step inter-subband absorption/recombination processes that are of paramount importance in a successful implementation high-efficiency IBSC. The experimental solar cell performance is further discussed, which has been recently demonstrated by using highly mismatched alloys and high-density quantum dot arrays and superlattice. IBSCs having widely different structures, materials, and spectral responses are also covered, as is the optimization of device parameters to achieve maximum performance.

  19. Tandem Microwire Solar Cells for Flexible High Efficiency Low Cost Photovoltaics

    SciTech Connect (OSTI)

    Atwater, Harry A.

    2015-03-10

    This project has developed components of a waferless, flexible, low-cost tandem multijunction III-V/Si microwire array solar cell technology which combines the efficiency of wafered III-V photovoltaic technologies with the process designed to meet the Sunshot object. The project focused on design of lattice-matched GaAsP/SiGe two junction cell design and lattice-mismatched GaInP/Si tandem cell design. Combined electromagnetic simulation/device physics models using realistic microwire tandem structures were developed that predict >22% conversion efficiency for known material parameters, such as tunnel junction structure, window layer structure, absorber lifetimes and optical absorption and these model indicate a clear path to 30% efficiency for high quality III-V heterostructures. SiGe microwire arrays were synthesized via Cu-catalyzed vapor-liquid-solid (VLS) growth with inexpensive chlorosilane and chlorogermance precursors in an atmospheric pressure reactor. SiGe alloy composition in microwires was found to be limited to a maximum of 12% Ge incorporation during chlorogermane growth, due to the melting of the alloy near the solidus composition. Lattice mismatched InGaP double heterostructures were grown by selective epitaxy with a thermal oxide mask on Si microwire substrates using metallorganic vapor phase epitaxy. Transmission electron microscopy (TEM) analysis confirms the growth of individual step graded layers and a high density of defects near the wire/III-V interface. Selective epitaxy was initiated with a low temperature nucleation scheme under “atomic layer epitaxy” or “flow mediated epitaxy” conditions whereby the Ga and P containing precursors are alternately introduced into the reactor to promote layer-bylayer growth. In parallel to our efforts on conformal GaInP heteroepitaxy on selectively masked Si microwires, we explored direct, axial growth of GaAs on Si wire arrays as another route to a tandem junction architecture. We proposed axial

  20. Photo of the Week: Record-Breaking Solar Cells | Department of Energy

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

    Record-Breaking Solar Cells Photo of the Week: Record-Breaking Solar Cells December 7, 2012 - 2:27pm Addthis Solar Junction, in partnership with NREL, has developed solar cells that reach a record-breaking 44 percent efficiency -- meaning that more than 40 percent of the sunlight the solar cells are exposed to is converted into electrical energy. In this photo, an operator inspects a photolithography tool used to manufacture these solar cells. | Photo by Daniel Derkacs/SolarJunction. Solar

  1. Comparison of single junction AlGaInP and GaInP solar cells grown by molecular beam epitaxy

    SciTech Connect (OSTI)

    Masuda, T; Tomasulo, S; Lang, JR; Lee, ML

    2015-03-07

    We have investigated similar to 2.0 eV (AlxGa1-x)(0.51)In0.49P and similar to 1.9 eV Ga0.51In0.49P single junction solar cells grown on both on-axis and misoriented GaAs substrates by molecular beam epitaxy (MBE). Although lattice-matched (AlxGa1-x)(0.51)In0.49P solar cells are highly attractive for space and concentrator photovoltaics, there have been few reports on the MBE growth of such cells. In this work, we demonstrate open circuit voltages (V-oc) ranging from 1.29 to 1.30 V for Ga0.51In0.49P cells, and 1.35-1.37 V for (AlxGa1-x)(0.51)In0.49P cells. Growth on misoriented substrates enabled the bandgap-voltage offset (W-oc = E-g/q - V-oc) of Ga0.51In0.49P cells to decrease from similar to 575 mV to similar to 565 mV, while that of (AlxGa1-x)(0.51)In0.49P cells remained nearly constant at 620 mV. The constant Woc as a function of substrate offcut for (AlxGa1-x)(0.51)In0.49P implies greater losses from non-radiative recombination compared with the Ga0.51In0.49P devices. In addition to larger Woc values, the (AlxGa1-x)(0.51)In0.49P cells exhibited significantly lower internal quantum efficiency (IQE) values than Ga0.51In0.49P cells due to recombination at the emitter/window layer interface. A thin emitter design is experimentally shown to be highly effective in improving IQE, particularly at short wavelengths. Our work shows that with further optimization of both cell structure and growth conditions, MBE-grown (AlxGa1-x)(0.51)In0.49P will be a promising wide-bandgap candidate material for high-efficiency, lattice-matched multi-junction solar cells. (C) 2015 AIP Publishing LLC.

  2. Thermodynamics of photon-enhanced thermionic emission solar cells

    SciTech Connect (OSTI)

    Reck, Kasper; Hansen, Ole

    2014-01-13

    Photon-enhanced thermionic emission (PETE) cells in which direct photon energy as well as thermal energy can be harvested have recently been suggested as a new candidate for high efficiency solar cells. Here, we present an analytic thermodynamical model for evaluation of the efficiency of PETE solar cells including an analysis of the entropy production due to thermionic emission of general validity. The model is applied to find the maximum efficiency of a PETE cell for given cathode and anode work functions and temperatures.

  3. Solar Photovoltaic Cell Basics | Department of Energy

    Office of Environmental Management (EM)

    ... Innovation U.S. Department of Energy to Invest up to 13.7 Million for Breakthrough Solar Energy Projects Energy Department Announces 12 Million to Accelerate Record-Breaking ...

  4. EERE Success Story-California: TetraCell Silicon Solar Cell Improves

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

    Efficiency, Wins R&D 100 Award | Department of Energy TetraCell Silicon Solar Cell Improves Efficiency, Wins R&D 100 Award EERE Success Story-California: TetraCell Silicon Solar Cell Improves Efficiency, Wins R&D 100 Award August 16, 2013 - 10:41am Addthis EERE Success Story—California: TetraCell Silicon Solar Cell Improves Efficiency, Wins R&D 100 Award TetraSun, in partnership with the National Renewable Energy Laboratory, developed a novel crystalline silicon

  5. 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.

  6. Method Of Making Solar Collectors By In-Situ Encapsulation Of Solar Cells

    DOE Patents [OSTI]

    Carrie, Peter J.; Chen, Kingsley D. D.

    2000-10-24

    A method of making solar collectors by encapsulating photovoltaic cells within a base of an elongated solar collector wherein heat and pressure are applied to the cells in-situ, after an encapsulating material has been applied. A tool is fashioned having a bladder expandable under gas pressure, filling a region of the collector where the cells are mounted. At the same time, negative pressure is applied outside of the bladder, enhancing its expansion. The bladder presses against a platen which contacts the encapsulated cells, causing outgassing of the encapsulant, while heat cures the encapsulant. After curing, the bladder is deflated and the tool may be removed from the collector and base and reflective panels put into place, if not already there, thereby allowing the solar collector to be ready for use.

  7. High Efficiency CdTe and CIGS Thin Film Solar Cells: Highlights...

    Office of Scientific and Technical Information (OSTI)

    Sponsoring Org: USDOE Country of Publication: United States Language: English Subject: 14 SOLAR ENERGY; 36 MATERIALS SCIENCE; EFFICIENCY; ENERGY CONVERSION; SOLAR CELLS; THIN FILMS ...

  8. Development of an electronic device quality aluminum antimonide (AlSb) semiconductor for solar cell applications

    SciTech Connect (OSTI)

    Sherohman, John W; Yee, Jick Hong; Combs, III, Arthur W

    2014-11-11

    Electronic device quality Aluminum Antimonide (AlSb)-based single crystals produced by controlled atmospheric annealing are utilized in various configurations for solar cell applications. Like that of a GaAs-based solar cell devices, the AlSb-based solar cell devices as disclosed herein provides direct conversion of solar energy to electrical power.

  9. Three dimensional amorphous silicon/microcrystalline silicon solar cells

    DOE Patents [OSTI]

    Kaschmitter, James L.

    1996-01-01

    Three dimensional deep contact amorphous silicon/microcrystalline silicon (a-Si/.mu.c-Si) solar cells which use deep (high aspect ratio) p and n contacts to create high electric fields within the carrier collection volume material of the cell. The deep contacts are fabricated using repetitive pulsed laser doping so as to create the high aspect p and n contacts. By the provision of the deep contacts which penetrate the electric field deep into the material where the high strength of the field can collect many of the carriers, thereby resulting in a high efficiency solar cell.

  10. Laminated photovoltaic modules using back-contact solar cells

    DOE Patents [OSTI]

    Gee, James M.; Garrett, Stephen E.; Morgan, William P.; Worobey, Walter

    1999-09-14

    Photovoltaic modules which comprise back-contact solar cells, such as back-contact crystalline silicon solar cells, positioned atop electrically conductive circuit elements affixed to a planar support so that a circuit capable of generating electric power is created. The modules are encapsulated using encapsulant materials such as EVA which are commonly used in photovoltaic module manufacture. The module designs allow multiple cells to be electrically connected in a single encapsulation step rather than by sequential soldering which characterizes the currently used commercial practices.

  11. AstroPower-DOE Collaboration Sets Solar Cell Record

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

    AstroPower-DOE Collaboration Sets Solar Cell Record For more information contact: Kerry Masson, (303) 275-4083 Golden, Colo., April 2, 1997—AstroPower, Inc., today announced it has fabricated a 16.6 percent efficient Silicon-Film™ solar cell as a result of government-industry collaboration with the U.S. Department of Energy (DOE) and DOE's National Renewable Energy Laboratory. The record, set on a 1-square-centimeter cell, was attained under DOE's Photovoltaic Manufacturing Technology (PVMaT)

  12. Three dimensional amorphous silicon/microcrystalline silicon solar cells

    DOE Patents [OSTI]

    Kaschmitter, J.L.

    1996-07-23

    Three dimensional deep contact amorphous silicon/microcrystalline silicon (a-Si/{micro}c-Si) solar cells are disclosed which use deep (high aspect ratio) p and n contacts to create high electric fields within the carrier collection volume material of the cell. The deep contacts are fabricated using repetitive pulsed laser doping so as to create the high aspect p and n contacts. By the provision of the deep contacts which penetrate the electric field deep into the material where the high strength of the field can collect many of the carriers, thereby resulting in a high efficiency solar cell. 4 figs.

  13. Thin film solar cell configuration and fabrication method

    DOE Patents [OSTI]

    Menezes, Shalini

    2009-07-14

    A new photovoltaic device configuration based on an n-copper indium selenide absorber and a p-type window is disclosed. A fabrication method to produce this device on flexible or rigid substrates is described that reduces the number of cell components, avoids hazardous materials, simplifies the process steps and hence the costs for high volume solar cell manufacturing.

  14. 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.

  15. Colloidal quantum dot solar cells on curved and flexible substrates

    SciTech Connect (OSTI)

    Kramer, Illan J.; Moreno-Bautista, Gabriel; Minor, James C.; Kopilovic, Damir; Sargent, Edward H.

    2014-10-20

    Colloidal quantum dots (CQDs) are semiconductor nanocrystals synthesized with, processed in, and deposited from the solution phase, potentially enabling low-cost, facile manufacture of solar cells. Unfortunately, CQD solar cell reports, until now, have only explored batch-processing methods—such as spin-coating—that offer limited capacity for scaling. Spray-coating could offer a means of producing uniform colloidal quantum dot films that yield high-quality devices. Here, we explore the versatility of the spray-coating method by producing CQD solar cells in a variety of previously unexplored substrate arrangements. The potential transferability of the spray-coating method to a roll-to-roll manufacturing process was tested by spray-coating the CQD active layer onto six substrates mounted on a rapidly rotating drum, yielding devices with an average power conversion efficiency of 6.7%. We further tested the manufacturability of the process by endeavoring to spray onto flexible substrates, only to find that spraying while the substrate was flexed was crucial to achieving champion performance of 7.2% without compromise to open-circuit voltage. Having deposited onto a substrate with one axis of curvature, we then built our CQD solar cells onto a spherical lens substrate having two axes of curvature resulting in a 5% efficient device. These results show that CQDs deposited using our spraying method can be integrated to large-area manufacturing processes and can be used to make solar cells on unconventional shapes.

  16. Semiconductor liquid-junction solar cell

    SciTech Connect (OSTI)

    Parkinson, B.A.

    1982-10-29

    A semiconductor liquid junction photocell in which the photocell is in the configuration of a light concentrator and in which the electrolytic solution both conducts current and facilitates the concentration of incident solar radiation onto the semiconductor. The photocell may be in the configuration of a non-imaging concentrator such as a compound parabolic concentrator, or an imaging concentrator such as a lens.

  17. Method of making quasi-grain boundary-free polycrystalline solar cell structure and solar cell structure obtained thereby

    DOE Patents [OSTI]

    Gonzalez, Franklin N.; Neugroschel, Arnost

    1984-02-14

    A new solar cell structure is provided which will increase the efficiency of polycrystalline solar cells by suppressing or completely eliminating the recombination losses due to the presence of grain boundaries. This is achieved by avoiding the formation of the p-n junction (or other types of junctions) in the grain boundaries and by eliminating the grain boundaries from the active area of the cell. This basic concept can be applied to any polycrystalline material; however, it will be most beneficial for cost-effective materials having small grains, including thin film materials.

  18. Effects of cell area on the performance of dye sensitized solar cell

    SciTech Connect (OSTI)

    Khatani, Mehboob E-mail: noranimuti-mohamed@petronas.com.my E-mail: azclement@yahoo.com Mohamed, Norani Muti E-mail: noranimuti-mohamed@petronas.com.my E-mail: azclement@yahoo.com Hamid, Nor Hisham E-mail: noranimuti-mohamed@petronas.com.my E-mail: azclement@yahoo.com Sahmer, Ahmad Zahrin E-mail: noranimuti-mohamed@petronas.com.my E-mail: azclement@yahoo.com Samsudin, Adel E-mail: noranimuti-mohamed@petronas.com.my E-mail: azclement@yahoo.com

    2014-10-24

    Dye sensitized solar cells (DSCs) have significant advantage over the current silicon cells by having low manufacturing cost and potentially high conversion efficiency. Therefore, DSCs are expected to be used as the next generation solar cell device that covers wide range of new applications. In order to achieve highly efficient DSCs for practical application, study on the effect of increasing the cell’s area on the performance of dye sensitized solar need to be carried out. Three different DSC cell areas namely, 1, 12.96 and 93.5 cm{sup 2} respectively were fabricated and analyzed through solar simulator and electrochemical impedance spectroscopy (EIS). From the analysis of electrochemical impedance spectroscopy (EIS), it was observed that the cell’s electron lifetime was influenced significantly by the cell’s area. Although the collection efficiency of all cells recorded to be approximately 100% but higher recombination rate with increased cell area reduced the performance of the cell.

  19. Recyclable organic solar cells on substrates comprising cellulose nanocrystals (CNC)

    SciTech Connect (OSTI)

    Kippelen, Bernard; Fuentes-Hernandez, Canek; Zhou, Yinhua; Moon, Robert; Youngblood, Jeffrey P

    2015-12-01

    Recyclable organic solar cells are disclosed herein. Systems and methods are further disclosed for producing, improving performance, and for recycling the solar cells. In certain example embodiments, the recyclable organic solar cells disclosed herein include: a first electrode; a second electrode; a photoactive layer disposed between the first electrode and the second electrode; an interlayer comprising a Lewis basic oligomer or polymer disposed between the photoactive layer and at least a portion of the first electrode or the second electrode; and a substrate disposed adjacent to the first electrode or the second electrode. The interlayer reduces the work function associated with the first or second electrode. In certain example embodiments, the substrate comprises cellulose nanocrystals that can be recycled. In certain example embodiments, one or more of the first electrode, the photoactive layer, and the second electrode may be applied by a film transfer lamination method.

  20. Quantum Dot Solar Cells with Multiple Exciton Generation

    SciTech Connect (OSTI)

    Hanna, M. C.; Beard, M. C.; Johnson, J. C.; Murphy, J.; Ellingson, R. J.; Nozik, A. J.

    2005-11-01

    We have measured the quantum yield of the multiple exciton generation (MEG) process in quantum dots (QDs) of the lead-salt semiconductor family (PbSe, PbTe, and PbS) using fs pump-probe transient absorption measurements. Very high quantum yields (up to 300%) for charge carrier generation from MEG have been measured in all of the Pb-VI QDs. We have calculated the potential maximum performance of various MEG QD solar cells in the detailed balance limit. We examined a two-cell tandem PV device with singlet fission (SF), QD, and normal dye (N) absorbers in the nine possible series-connected combinations to compare the tandem combinations and identify the combinations with the highest theoretical efficiency. We also calculated the maximum efficiency of an idealized single-gap MEG QD solar cell with M multiplications and its performance under solar concentration.

  1. Method of making a back contacted solar cell

    DOE Patents [OSTI]

    Gee, James M. (Albuquerque, NM)

    1995-01-01

    A back-contacted solar cell having laser-drilled vias connecting the front-surface carrier-collector junction to an electrode grid on the back surface. The structure may also include a rear surface carrier-collector junction connected to the same grid. The substrate is connected to a second grid which is interdigitated with the first. Both grids are configured for easy series connection with neighboring cells. Several processes are disclosed to produce the cell.

  2. Solar Foundational Program to Advance Cell Efficiency Round 2 | Department

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

    of Energy 2 Solar Foundational Program to Advance Cell Efficiency Round 2 The SunShot Foundational Program to Advance Cell Efficiency (F-PACE) aims to increase the efficiency of photovoltaic (PV) cells achieved in the laboratory and on manufacturing lines. Launched in September 2011, the first round of the F-PACE program supported 18 research projects over a 36-month performance period. These efforts laid the technical foundation for significant increases in PV efficiency by identifying cost

  3. Method of making a back contacted solar cell

    DOE Patents [OSTI]

    Gee, J.M.

    1995-11-21

    A back-contacted solar cell is described having laser-drilled vias connecting the front-surface carrier-collector junction to an electrode grid on the back surface. The structure may also include a rear surface carrier-collector junction connected to the same grid. The substrate is connected to a second grid which is interdigitated with the first. Both grids are configured for easy series connection with neighboring cells. Several processes are disclosed to produce the cell. 2 figs.

  4. New approaches for high-efficiency solar cells. Final report

    SciTech Connect (OSTI)

    Bedair, S.M.; El-Masry, N.A.

    1997-12-01

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

  5. Berkeley Lab Sheds Light on Improving Solar Cell Efficiency

    SciTech Connect (OSTI)

    Lawrence Berkeley National Laboratory

    2007-07-20

    Typical manufacturing methods produce solar cells with an efficiency of 12-15%; and 14% efficiency is the bare minimum for achieving a profit. In work performed at the Ernest Orlando Lawrence Berkeley National Laboratory (Berkeley, CA, 5 10-486-577 1)--a US Department of Energy national laboratory that conducts unclassified scientific research and is managed by the University of California--scientist Scott McHugo has obtained keen insights into the impaired performance of solar cells manufactured from polycrystalline silicon. The solar cell market is potentially vast, according to Berkeley Lab. Lightweight solar panels are highly beneficial for providing electrical power to remote locations in developing nations, since there is no need to build transmission lines or truck-in generator fuel. Moreover, industrial nations confronted with diminishing resources have active programs aimed at producing improved, less expensive solar cells. 'In a solar cell, there is a junction between p-type silicon and an n-type layer, such as diffused-in phosphorous', explained McHugo, who is now with Berkeley Lab's Accelerator and Fusion Research Division. 'When sunlight is absorbed, it frees electrons, which start migrating in a random-walk fashion toward that junction. If the electrons make it to the junction; they contribute to the cell's output of electric current. Often, however, before they reach the junction, they recombine at specific sites in the crystal' (and, therefore, cannot contribute to current output). McHugo scrutinized a map of a silicon wafer in which sites of high recombination appeared as dark regions. Previously, researchers had shown that such phenomena occurred not primarily at grain boundaries in the polycrystalline material, as might be expected, but more often at dislocations in the crystal. However, the dislocations themselves were not the problem. Using a unique heat treatment technique, McHugo performed electrical measurements to investigate the material

  6. 0.7-eV GaInAs Junction for a GaInP/GaAs/GaInAs(1-eV)/GaInAs(0.7-eV) Four-Junction Solar Cell: Preprint

    SciTech Connect (OSTI)

    Friedman, D. J.; Geisz, J. F.; Norman, A. G.; Wanlass, M. W.; Kurtz, S. R.

    2006-05-01

    We discuss recent developments in III-V multijunction solar cells, focusing on adding a fourth junction to the Ga0.5In0.5P/GaAs/Ga0.75In0.25As inverted three-junction cell. This cell, grown inverted on GaAs so that the lattice-mismatched Ga0.75In0.25As third junction is the last one grown, has demonstrated 38% efficiency, and 40% is likely in the near future. To achieve still further gains, a lower-bandgap GaxIn1-xAs fourth junction could be added to the three-junction structure for a four-junction cell whose efficiency could exceed 45% under concentration. Here, we present the initial development of the GaxIn1-xAs fourth junction. Junctions of various bandgaps ranging from 0.88 to 0.73 eV were grown, in order to study the effect of the different amounts of lattice mismatch. At a bandgap of 0.88 eV, junctions were obtained with very encouraging {approx}80% quantum efficiency, 57% fill factor, and 0.36 eV open-circuit voltage. The device performance degrades with decreasing bandgap (i.e., increasing lattice mismatch). We model the four-junction device efficiency vs. fourth junction bandgap to show that an 0.7-eV fourth-junction bandgap, while optimal if it could be achieved in practice, is not necessary; an 0.9-eV bandgap would still permit significant gains in multijunction cell efficiency while being easier to achieve than the lower-bandgap junction.

  7. Fabrication of solar cells with counter doping prevention

    DOE Patents [OSTI]

    Dennis, Timothy D; Li, Bo; Cousins, Peter John

    2013-02-19

    A solar cell fabrication process includes printing of dopant sources over a polysilicon layer over backside of a solar cell substrate. The dopant sources are cured to diffuse dopants from the dopant sources into the polysilicon layer to form diffusion regions, and to crosslink the dopant sources to make them resistant to a subsequently performed texturing process. To prevent counter doping, dopants from one of the dopant sources are prevented from outgassing and diffusing into the other dopant source. For example, phosphorus from an N-type dopant source is prevented from diffusing to a P-type dopant source comprising boron.

  8. Solar cells: what you always wanted to know

    SciTech Connect (OSTI)

    Laws, R.J.

    1983-01-01

    This book discusses the development in the photovoltaics field that has made it economically feasible to consider the use of solar cells as an alternative energy source. There are numerous ecological benefits to the use of solar cell generated electricity. Information is presented that can be used by homeowners, architects, and builders, both to develop do-it-yourself systems and as a guide when dealing with professional installers. A special appendix of exercises is provided to give the reader more practice in estimating system requirements.

  9. Process Development for High Voc CdTe Solar Cells

    SciTech Connect (OSTI)

    Ferekides, C. S.; Morel, D. L.

    2011-05-01

    This is a cumulative and final report for Phases I, II and III of this NREL funded project (subcontract # XXL-5-44205-10). The main research activities of this project focused on the open-circuit voltage of the CdTe thin film solar cells. Although, thin film CdTe continues to be one of the leading materials for large-scale cost-effective production of photovoltaics, the efficiency of the CdTe solar cells have been stagnant for the last few years. This report describes and summarizes the results for this 3-year research project.

  10. Thin film solar cell including a spatially modulated intrinsic layer

    SciTech Connect (OSTI)

    Guha, Subhendu; Yang, Chi-Chung; Ovshinsky, Stanford R.

    1989-03-28

    One or more thin film solar cells in which the intrinsic layer of substantially amorphous semiconductor alloy material thereof includes at least a first band gap portion and a narrower band gap portion. The band gap of the intrinsic layer is spatially graded through a portion of the bulk thickness, said graded portion including a region removed from the intrinsic layer-dopant layer interfaces. The band gap of the intrinsic layer is always less than the band gap of the doped layers. The gradation of the intrinsic layer is effected such that the open circuit voltage and/or the fill factor of the one or plural solar cell structure is enhanced.

  11. High-efficiency solar cells using HEM silicon

    SciTech Connect (OSTI)

    Khattak, C.P.; Schmid, F.; Schubert, W.K.

    1994-12-31

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

  12. Substrate for thin silicon solar cells

    DOE Patents [OSTI]

    Ciszek, Theodore F. (Evergreen, CO)

    1995-01-01

    A photovoltaic device for converting solar energy into electrical signals comprises a substrate, a layer of photoconductive semiconductor material grown on said substrate, wherein the substrate comprises an alloy of boron and silicon, the boron being present in a range of from 0.1 to 1.3 atomic percent, the alloy having a lattice constant substantially matched to that of the photoconductive semiconductor material and a resistivity of less than 1.times.10.sup.-3 ohm-cm.

  13. Substrate for thin silicon solar cells

    DOE Patents [OSTI]

    Ciszek, T.F.

    1995-03-28

    A photovoltaic device for converting solar energy into electrical signals comprises a substrate, a layer of photoconductive semiconductor material grown on said substrate, wherein the substrate comprises an alloy of boron and silicon, the boron being present in a range of from 0.1 to 1.3 atomic percent, the alloy having a lattice constant substantially matched to that of the photoconductive semiconductor material and a resistivity of less than 1{times}10{sup {minus}3} ohm-cm. 4 figures.

  14. Copper doped polycrystalline silicon solar cell

    DOE Patents [OSTI]

    Lovelace, Alan M. Administrator of the National Aeronautics and Space; Koliwad, Krishna M.; Daud, Taher

    1981-01-01

    Photovoltaic cells having improved performance are fabricated from polycrystalline silicon containing copper segregated at the grain boundaries.

  15. High-efficiency silicon heterojunction solar cells: Status and perspectives

    SciTech Connect (OSTI)

    De Wolf, S.; Geissbuehler, J.; Loper, P.; Martin de Nicholas, S.; Seif, J.; Tomasi, A.; Ballif, C.

    2015-05-11

    Silicon heterojunction technology (HJT) uses silicon thin-film deposition techniques to fabricate photovoltaic devices from mono-crystalline silicon wafers (c-Si). This enables energy-conversion efficiencies above 21 %, also at industrial-production level. In this presentation we review the present status of this technology and point out recent trends. We first discuss how the properties of thin hydrogenated amorphous silicon (a-Si:H) films can be exploited to fabricate passivating contacts, which is the key to high- efficiency HJT solar cells. Such contacts enable very high operating voltages, approaching the theoretical limits, and yield small temperature coefficients. With this approach, an increasing number of groups are reporting devices with conversion efficiencies well over 20 % on both-sides contacted n-type cells, Panasonic leading the field with 24.7 %. Exciting results have also been obtained on p-type wafers. Despite these high voltages, important efficiency gains can still be made in fill factor and optical design. This requires improved understanding of carrier transport across device interfaces and reduced parasitic absorption in HJT solar cells. For the latter, several strategies can be followed: Short-wavelength losses can be reduced by replacing the front a-Si:H films with wider-bandgap window layers, such as silicon alloys or even metal oxides. Long- wavelength losses are mitigated by introducing new high-mobility TCO’s such as hydrogenated indium oxide, and also by designing new rear reflectors. Optical shadow losses caused by the front metallization grid are significantly reduced by replacing printed silver electrodes with fine-line plated copper contacts, leading also to possible cost advantages. The ultimate approach to minimize optical losses is the implementation of back-contacted architectures, which are completely devoid of grid shadow losses and parasitic absorption in the front layers can be minimized irrespective of electrical

  16. CIGS Thin-Film Solar Cell Research at NREL: FY04 Results and...

    Office of Scientific and Technical Information (OSTI)

    CIGS Thin-Film Solar Cell Research at NREL: FY04 Results and Accomplishments Citation Details In-Document Search Title: CIGS Thin-Film Solar Cell Research at NREL: FY04 Results and ...

  17. Discovering an Active Subspace in a Single-Diode Solar Cell Model...

    Office of Scientific and Technical Information (OSTI)

    Discovering an Active Subspace in a Single-Diode Solar Cell Model Citation Details In-Document Search Title: Discovering an Active Subspace in a Single-Diode Solar Cell Model ...

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

    SciTech Connect (OSTI)

    Not Available

    2011-05-01

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

  19. High-Efficiency GaAs Thin-Film Solar Cell Reliability | Department...

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

    GaAs Thin-Film Solar Cell Reliability High-Efficiency GaAs Thin-Film Solar Cell Reliability Presented at the PV Module Reliability Workshop, February 26 - 27 2013, Golden, Colorado ...

  20. Current enhancement of CdTe-based solar cells (Journal Article...

    Office of Scientific and Technical Information (OSTI)

    Current enhancement of CdTe-based solar cells This content will become publicly available on July 30, 2016 Prev Next Title: Current enhancement of CdTe-based solar cells We ...

  1. Current enhancement of CdTe-based solar cells (Journal Article...

    Office of Scientific and Technical Information (OSTI)

    CdTe-based solar cells Citation Details In-Document Search This content will become publicly available on July 30, 2016 Title: Current enhancement of CdTe-based solar cells We ...

  2. High-efficiency silicon heterojunction solar cells: Status and perspectives

    SciTech Connect (OSTI)

    De Wolf, S.

    2015-04-27

    Silicon heterojunction technology (HJT) uses silicon thin-film deposition techniques to fabricate photovoltaic devices from mono-crystalline silicon wafers (c-Si). This enables energy-conversion efficiencies above 21 %, also at industrial-production level. In this presentation we review the present status of this technology and point out recent trends. We first discuss how the properties of thin hydrogenated amorphous silicon (a-Si:H) films can be exploited to fabricate passivating contacts, which is the key to high- efficiency HJT solar cells. Such contacts enable very high operating voltages, approaching the theoretical limits, and yield small temperature coefficients. With this approach, an increasing number of groups are reporting devices with conversion efficiencies well over 20 % on n-type wafers, Panasonic leading the field with 24.7 %. Exciting results have also been obtained on p-type wafers. Despite these high voltages, important efficiency gains can still be made in fill factor and optical design. This requires improved understanding of carrier transport across device interfaces and reduced parasitic absorption in HJT solar cells. For the latter, several strategies can be followed: Short- wavelength losses can be reduced by replacing the front a-Si:H films with wider-bandgap window layers, such as silicon alloys or even metal oxides. Long-wavelength losses are mitigated by introducing new high-mobility TCO’s such as hydrogenated indium oxide, and also by designing new rear reflectors. Optical shadow losses caused by the front metalisation grid are significantly reduced by replacing printed silver electrodes with fine-line plated copper contacts, leading also to possible cost advantages. The ultimate approach to minimize optical losses is the implementation of back-contacted architectures, which are completely devoid of grid shadow losses and parasitic absorption in the front layers can be minimized irrespective of electrical transport requirements. The

  3. 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.

  4. Enhanced regeneration of degraded polymer solar cells by thermal annealing

    SciTech Connect (OSTI)

    Kumar, Pankaj; Bilen, Chhinder; Zhou, Xiaojing; Belcher, Warwick J.; Dastoor, Paul C.; Feron, Krishna

    2014-05-12

    The degradation and thermal regeneration of poly(3-hexylethiophene) (P3HT):[6,6]-phenyl-C{sub 61}-butyric acid methyl ester (PCBM) and P3HT:indene-C{sub 60} bisadduct (ICBA) polymer solar cells, with Ca/Al and Ca/Ag cathodes and indium tin oxide/poly(ethylene-dioxythiophene):polystyrene sulfonate anode have been investigated. Degradation occurs via a combination of three primary pathways: (1) cathodic oxidation, (2) active layer phase segregation, and (3) anodic diffusion. Fully degraded devices were subjected to thermal annealing under inert atmosphere. Degraded solar cells possessing Ca/Ag electrodes were observed to regenerate their performance, whereas solar cells having Ca/Al electrodes exhibited no significant regeneration of device characteristics after thermal annealing. Moreover, the solar cells with a P3HT:ICBA active layer exhibited enhanced regeneration compared to P3HT:PCBM active layer devices as a result of reduced changes to the active layer morphology. Devices combining a Ca/Ag cathode and P3HT:ICBA active layer demonstrated ∼50% performance restoration over several degradation/regeneration cycles.

  5. Amorphous silicon solar cells techniques for reactive conditions

    SciTech Connect (OSTI)

    Shimizu, Satoshi; Okawa, Kojiro; Kamiya, Toshio; Fortmann, C.M.; Shimizu, Isamu

    1999-07-01

    The preparation of amorphous silicon films and solar cells using SiH{sub 2}Cl{sub 2} source gas and electron cyclotron resonance assisted chemical vapor deposition (ECR-CVD) was investigated. By using buffer layers to protect previously deposited layers improved a-Si:H(Cl) solar cells were prepared and studied. The high quality a-Si:H(Cl) films used in this study exhibited low defect densities ({approximately}10{sup 15} cm{sup {minus}3}) and high stability under illumination even when the deposition rate was increased to {approximately} 15A/s. The solar cells were deposited in the n-i-p sequence. These solar cells achieved V{sub oc} values of {approximately}0.89V and {approximately}3.9% efficiency on Ga doped ZnO (GZO) coated specular substrate. The a-Si:H(Cl) electron and hole {mu}{tau} products were {approximately}10{sup {minus}8} cm{sup 2}/V.

  6. NREL Success Stories - Quest for Inexpensive Silicon Solar Cells

    ScienceCinema (OSTI)

    Branz, Howard

    2013-05-29

    Scientists at the National Renewable Energy Laboratory (NREL) share their story about a successful partnership with Oak Ridge National Laboratory and the Ampulse Corporation and how support from the US Department of Energy's Technology Commercialization & Deployment Fund has helped it and their silicon solar cell research thrive.

  7. Performance model assessment for multi-junction concentrating photovoltaic systems.

    SciTech Connect (OSTI)

    Stein, Joshua S.; Riley, Daniel M.; McConnell, Robert.; Sahm, Aaron; Crawford, Clark; King, David L.; Cameron, Christopher P.; Foresi, James S.

    2010-03-01

    Four approaches to modeling multi-junction concentrating photovoltaic system performance are assessed by comparing modeled performance to measured performance. Measured weather, irradiance, and system performance data were collected on two systems over a one month period. Residual analysis is used to assess the models and to identify opportunities for model improvement. Large photovoltaic systems are typically developed as projects which supply electricity to a utility and are owned by independent power producers. Obtaining financing at favorable rates and attracting investors requires confidence in the projected energy yield from the plant. In this paper, various performance models for projecting annual energy yield from Concentrating Photovoltaic (CPV) systems are assessed by comparing measured system output to model predictions based on measured weather and irradiance data. The results are statistically analyzed to identify systematic error sources.

  8. Optical system for determining physical characteristics of a solar cell

    DOE Patents [OSTI]

    Sopori, Bhushan L.

    2001-01-01

    The invention provides an improved optical system for determining the physical characteristics of a solar cell. The system comprises a lamp means for projecting light in a wide solid-angle onto the surface of the cell; a chamber for receiving the light through an entrance port, the chamber having an interior light absorbing spherical surface, an exit port for receiving a beam of light reflected substantially normal to the cell, a cell support, and an lower aperture for releasing light into a light absorbing baffle; a means for dispersing the reflection into monochromatic components; a means for detecting an intensity of the components; and a means for reporting the determination.

  9. Approach towards high efficiency polycrystalline silicon solar cells

    SciTech Connect (OSTI)

    Rohatgi, A.; Sana, P.; Chen, Z.; Salami, J. )

    1992-12-01

    A combination of theoretical modelling, gettering and passivation, and cell fabrication is presented in this paper to provide guidelines for improving efficiency of polycrystalline solar cells. Theoretical modelling was performed to show that grain boundary barrier height decreases and carrier diffusion length increases with illumination level ([le]50 suns) in those polycrystalline materials where grain boundary dominates the recombination. Model calculations show that the efficiency spread due to grain boundary defect density ([ital N][sub [ital st

  10. Solar Photovoltaic Cell/Module Shipments Report July 2016

    U.S. Energy Information Administration (EIA) Indexed Site

    Photovoltaic Cell/Module Shipments Report July 2016 Independent Statistics & Analysis www.eia.gov U.S. Department of Energy Washington, DC 20585 U.S. Energy Information Administration | Solar Photovoltaic Cell/Module Shipments Report 1 This report was prepared by the U.S. Energy Information Administration (EIA), the statistical and analytical agency within the U.S. Department of Energy. By law, EIA's data, analyses, and forecasts are independent of approval by any other officer or employee

  11. High performance planar p-i-n perovskite solar cells with crown...

    Office of Scientific and Technical Information (OSTI)

    College of Chemistry, Chemical Engineering and Materials Science, Soochow ... INTERFACES; LAYERS; LITHIUM FLUORIDES; OPTIMIZATION; PEROVSKITE; SOLAR CELLS; SPIN-ON ...

  12. 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.

  13. Solar Cells from Earth-Abundant Semiconductors with Plasmon-Enhanced Light Absorption

    SciTech Connect (OSTI)

    Atwater, Harry

    2012-04-30

    Progress is reported in these areas: Plasmonic Light Trapping in Thin Film a-Si Solar Cells; Plasmonic Light Trapping in Thin InGaN Quantum Well Solar Cells; and Earth Abundant Cu{sub 2}O and Zn{sub 3}P{sub 2} Solar Cells.

  14. Biomimetic Dye Molecules for Solar Cells

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

    cell. The class of dye molecules used in this research is related to the dye that gives blue jeans their color. By choosing organic molecules, an enormous repertoire of possible...

  15. Thin-Film Solar Cell Manufacturing

    Broader source: Energy.gov [DOE]

    In this b-roll, thin-film photovoltaic cells are manufactured and deployed in Arizona. Steps shown in the manufacturing process include the screen printing of conductive material onto laminated...

  16. Photo electrochemical and organic-based solar cells

    SciTech Connect (OSTI)

    Lewis, N.S.; Kamat, P.; Spitler, M.

    1996-09-01

    Research in solar photoconversion has resulted in significant advances in the fields of photoelectrochemistry and dye-sensitized solar cells. Progress is also evident in the understanding of solid state organic systems for energy transduction. It is evident, however, that the examination in this report of the accomplishments in these areas serves to highlight the great extent of research that is necessary to establish a technology base sufficient for practical application. Recommendations are made in this report on the directions that this research should take.

  17. Improved Electrodes and Electrolytes for Dye-Based Solar Cells

    SciTech Connect (OSTI)

    Harry R. Allcock; Thomas E. Mallouk; Mark W. Horn

    2011-10-26

    The most important factor in limiting the stability of dye-sensitized solar cells is the use of volatile liquid solvents in the electrolytes, which causes leakage during extended operation especially at elevated temperatures. This, together with the necessary complex sealing of the cells, seriously hampers the industrial-scale manufacturing and commercialization feasibilities of DSSCs. The objective of this program was to bring about a significant improvement in the performance and longevity of dye-based solar cells leading to commercialization. This had been studied in two ways first through development of low volatility solid, gel or liquid electrolytes, second through design and fabrication of TiO2 sculptured thin film electrodes.

  18. Low cost and efficient photovoltaic conversion by nanocrystalline solar cells

    SciTech Connect (OSTI)

    Graetzel, M.

    1996-09-01

    Solar cells are expected to provide environmentally friendly solutions to the world`s energy supply problem. Learning from the concepts used by green plants we have developed a molecular photovoltaic device whose overall efficiency for AM 1.5 solar light to electricity has already attained 8-11%. The system is based on the sensitization of nanocrystalline oxide films by transition metal charge transfer sensitizers. In analogy to photosynthesis, the new chemical solar cell achieves the separation of the light absorption and charge carrier transport processes. Extraordinary yields for the conversion of incident photons into electric current are obtained, exceeding 90% for transition metal complexes within the wavelength range of their absorption band. The use of molten salt electrolytes together with coordination complexes of ruthenium as sensitizers and adequate sealing technology has endowed these cells with a remarkable stability making practical applications feasible. Seven industrial cooperations are presently involved in the development to bring these cells to the market. The first cells will be applied to supply electric power for consumer electronic devices. The launching of production of several products of this type is imminent and they should be on the market within the next two years. Quite aside from their intrinsic merits as photovoltaic device, the mesoscopic oxide semiconductor films developed in our laboratory offer attractive possibilities for a number of other applications. Thus, the first example of a nanocrystalline rocking chair battery will be demonstrated and its principle briefly discussed.

  19. Flexible Thin-Film Silicon Solar Cells

    SciTech Connect (OSTI)

    Vijh, Aarohi; Cao, Simon; Mohring, Brad

    2014-01-11

    High fuel costs, environmental concerns and issues of national energy security have brought increasing attention to a distributed generation program for electricity based on solar technology. Rooftop photovoltaic (PV) systems provide distributed generation since the power is consumed at the point of production, thus eliminating the need for costly additional transmission lines. However, most current photovoltaic modules are heavy and require a significant amount of labor and accessory hardware such as mounting frames for installation on rooftops. This makes rooftop systems impractical or cost prohibitive in many instances. Under this project, Xunlight has advanced its manufacturing process for the production of lightweight, flexible thin-film silicon based photovoltaic modules, and has enhanced the reliability and performance of Xunlights products. These modules are easily unrolled and adhered directly to standard commercial roofs without mounting structures or integrated directly into roofing membrane materials for the lowest possible installation costs on the market. Importantly, Xunlight has now established strategic alliances with roofing material manufacturers and other OEMs for the development of building integrated photovoltaic roofing and other PV-enabled products, and has deployed its products in a number of commercial installations with these business partners.

  20. Method for cleaning a solar cell surface opening made with a solar etch paste

    DOE Patents [OSTI]

    Rohatgi, Ajeet; Meemongkolkiat, Vichai

    2010-06-22

    A thin silicon solar cell having a back dielectric passivation and rear contact with local back surface field is described. Specifically, the solar cell may be fabricated from a crystalline silicon wafer having a thickness from 50 to 500 micrometers. A barrier layer and a dielectric layer are applied at least to the back surface of the silicon wafer to protect the silicon wafer from deformation when the rear contact is formed. At least one opening is made to the dielectric layer. An aluminum contact that provides a back surface field is formed in the opening and on the dielectric layer. The aluminum contact may be applied by screen printing an aluminum paste having from one to 12 atomic percent silicon and then applying a heat treatment at 750 degrees Celsius.

  1. Interface engineering for efficient fullerene-free organic solar cells

    SciTech Connect (OSTI)

    Shivanna, Ravichandran; Narayan, K. S. E-mail: narayan@jncasr.ac.in; Rajaram, Sridhar E-mail: narayan@jncasr.ac.in

    2015-03-23

    We demonstrate the role of zinc oxide (ZnO) morphology and addition of an acceptor interlayer to achieve high efficiency fullerene-free bulk heterojunction inverted organic solar cells. Nanopatterning of the ZnO buffer layer enhances the effective light absorption in the active layer, and the insertion of a twisted perylene acceptor layer planarizes and decreases the electron extraction barrier. Along with an increase in current homogeneity, the reduced work function difference and selective transport of electrons prevent the accumulation of charges and decrease the electron-hole recombination at the interface. These factors enable an overall increase of efficiency to 4.6%, which is significant for a fullerene-free solution-processed organic solar cell.

  2. Transparent conductor-embedding nanolens for Si solar cells

    SciTech Connect (OSTI)

    Kim, Joondong E-mail: junsin@skku.edu Kumar, Melvin David; Yun, Ju-Hyung; Kim, Hongsik; Park, Hyeong-Ho; Lee, Eunsongyi; Kim, Dong-wook; Kim, Hyunyub; Kim, Mingeon; Yi, Junsin E-mail: junsin@skku.edu; Jeong, Chaehwan E-mail: junsin@skku.edu

    2015-04-13

    We present a large-scale applicable nanolens-embedding solar cell. An electrically conductive and optically transparent indium-tin-oxide (ITO) thin film was coated on a Si substrate. After then, periodically patterned ITO nanodome-arrays were formed on the ITO film by using a nano-imprint method. This structure is effective to reduce the incident light reflection for broad wavelengths and also efficient to drive the incident photons into a light-absorbing Si substrate. There exist two electric fields. One is by a p/n junction and the other is by the light absorption into Si. We designed nanolens structures to overlap two electric fields and demonstrate highly improved solar cell performances of current and voltage values from a planar structure.

  3. Towards understanding junction degradation in cadmium telluride solar cells

    SciTech Connect (OSTI)

    Nardone, Marco

    2014-06-21

    A degradation mechanism in cadmium telluride (CdTe/CdS) solar cells is investigated using time-dependent numerical modeling to simulate various temperature, bias, and illumination stress conditions. The physical mechanism is based on defect generation rates that are proportional to nonequilibrium charge carrier concentrations. It is found that a commonly observed degradation mode for CdTe/CdS solar cells can be reproduced only if defects are allowed to form in a narrow region of the absorber layer close to the CdTe/CdS junction. A key aspect of this junction degradation is that both mid-gap donor and shallow acceptor-type defects must be generated simultaneously in response to photo-excitation or applied bias. The numerical approach employed here can be extended to study other mechanisms for any photovoltaic technology.

  4. Modeling Copper Diffusion in Polycrystalline CdTe Solar Cells

    SciTech Connect (OSTI)

    Akis, Richard; Brinkman, Daniel; Sankin, Igor; Fang, Tian; Guo, Da; Vasileska, Dragica; Ringhofer, Christain

    2014-06-06

    It is well known that Cu plays an important role in CdTe solar cell performance as a dopant. In this work, a finite-difference method is developed and used to simulate Cu diffusion in CdTe solar cells. In the simulations, which are done on a two-dimensional (2D) domain, the CdTe is assumed to be polycrystalline, with the individual grains separated by grain boundaries. When used to fit experimental Cu concentration data, bulk and grain boundary diffusion coefficients and activation energies for CdTe can be extracted. In the past, diffusion coefficients have been typically obtained by fitting data to simple functional forms of limited validity. By doing full simulations, the simplifying assumptions used in those analytical models are avoided and diffusion parameters can thus be determined more accurately

  5. Design for the fabrication of high efficiency solar cells

    DOE Patents [OSTI]

    Simmons, Joseph H.

    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.

  6. Methods for improving solar cell open circuit voltage

    DOE Patents [OSTI]

    Jordan, John F.; Singh, Vijay P.

    1979-01-01

    A method for producing a solar cell having an increased open circuit voltage. A layer of cadmium sulfide (CdS) produced by a chemical spray technique and having residual chlorides is exposed to a flow of hydrogen sulfide (H.sub.2 S) heated to a temperature of 400.degree.-600.degree. C. The residual chlorides are reduced and any remaining CdCl.sub.2 is converted to CdS. A heterojunction is formed over the CdS and electrodes are formed. Application of chromium as the positive electrode results in a further increase in the open circuit voltage available from the H.sub.2 S-treated solar cell.

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

    SciTech Connect (OSTI)

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

    1991-01-01

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

  8. Radial electron collection in dye-sensitized solar cells.

    SciTech Connect (OSTI)

    Martinson, A. B. B.; Elam, J. W.; Liu, J.; Pellin, M. J.; Marks, T. J.; Hupp, J. T.; Materials Science Division; Northwestern Univ.

    2008-01-01

    We introduce a new photoelectrode architecture consisting of concentric conducting and semiconducting nanotubes for use in dye-sensitized solar cells (DSSCs). Atomic layer deposition is employed to grow indium tin oxide (ITO) within a porous template and subsequently coat the high area photoelectrode with amorphous TiO2. Compared with control devices lacking a current collector within the pores, the new photoelectrode geometry exhibits dramatically higher current densities, an effect attributed to the radial collection of electrons.

  9. PROJECT PROFILE: Stable Perovskite Solar Cells via Chemical Vapor Deposition

    Broader source: Energy.gov [DOE]

    This project is focused on novel approaches to remove risk related to the development of hybrid perovskite solar cells (HPSCs). Researchers will synthesize a new and chemically stable hybrid organic-inorganic perovskite that eliminates decomposition of the absorber layer upon exposure to water vapor, which is a chief obstacle to widespread use of HPSC technology. They will also demonstrate a unique and industrially-scalable chemical vapor deposition method without halides or iodine, which are the main contributors to perovskite degradation.

  10. Alan J. Heeger, Conductive Polymers, and Plastic Solar Cells

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

    Alan J. Heeger, Conductive Polymers, and Plastic Solar Cells Resources with Additional Information * Patents * Videos After receiving 'his physics Ph.D. at the University of California at Berkeley in 1961, [Alan J.] Heeger would spend the next 20 years teaching the subject at the University of Pennsylvania - while also designing and then launching one of the nation's premiere scientific think tanks: the Laboratory for Research on the Structure of Matter. Alan J. Heeger Courtesy of Randy Lamb,

  11. $6 Million in Awards to Advance Solar Cell Research

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

    $6 Million in Awards to Advance Solar Cell Research For more information contact: George Douglas, 303-275-4096 email: George Douglas Golden, Colo., Apr. 13, 2001 - The U.S. Department of Energy's National Renewable Energy Laboratory (NREL) today announced $6 million in awards to 11 universities and five companies for high tech research into non-conventional, photovoltaic technologies for creating electricity from sunlight. Each award has the potential to create a breakthrough that could

  12. Encapsulant Material For Solar Cell Module And Laminated Glass Applications

    DOE Patents [OSTI]

    Hanoka, Jack I.

    2000-09-05

    An encapsulant material includes a layer of metallocene polyethylene disposed between two layers of ionomer. More specifically, the layer of metallocene polyethylene is disposed adjacent a rear surface of the first ionomer layer, and a second layer of ionomer is disposed adjacent a rear surface of the layer of metallocene polyethylene. The encapsulant material can be used in solar cell module and laminated glass applications.

  13. Junction Transport in Epitaxial Film Silicon Heterojunction Solar Cells

    SciTech Connect (OSTI)

    Young, D. L.; Li, J. V.; Teplin, C. W.; Stradins, P.; Branz, H. M.

    2011-01-01

    We report our progress toward low-temperature HWCVD epitaxial film silicon solar cells on inexpensive seed layers, with a focus on the junction transport physics exhibited by our devices. Heterojunctions of i/p hydrogenated amorphous Si (a-Si) on our n-type epitaxial crystal Si on n{sup ++} Si wafers show space-charge-region recombination, tunneling or diffusive transport depending on both epitaxial Si quality and the applied forward voltage.

  14. Junction Transport in Epitaxial Film Silicon Heterojunction Solar Cells: Preprint

    SciTech Connect (OSTI)

    Young, D. L.; Li, J. V.; Teplin, C. W.; Stradins, P.; Branz, H. M.

    2011-07-01

    We report our progress toward low-temperature HWCVD epitaxial film silicon solar cells on inexpensive seed layers, with a focus on the junction transport physics exhibited by our devices. Heterojunctions of i/p hydrogenated amorphous Si (a-Si) on our n-type epitaxial crystal Si on n++ Si wafers show space-charge-region recombination, tunneling or diffusive transport depending on both epitaxial Si quality and the applied forward voltage.

  15. Solar cell comprising a plasmonic back reflector and method therefor

    DOE Patents [OSTI]

    Ding, I-Kang; Zhu, Jia; Cui, Yi; McGehee, Michael David

    2014-11-25

    A method for forming a solar cell having a plasmonic back reflector is disclosed. The method includes the formation of a nanoimprinted surface on which a metal electrode is conformally disposed. The surface structure of the nanoimprinted surface gives rise to a two-dimensional pattern of nanometer-scale features in the metal electrode enabling these features to collectively form the plasmonic back reflector.

  16. Breakthrough Monitoring Technology Reduces Time and Expense in Solar Cell

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

    Manufacturing Process | U.S. DOE Office of Science (SC) Breakthrough Monitoring Technology Reduces Time and Expense in Solar Cell Manufacturing Process Small Business Innovation Research (SBIR) and Small Business Technology Transfer (STTR) SBIR/STTR Home About Funding Opportunity Announcements (FOAs) Applicant and Awardee Resources Commercialization Assistance Other Resources Awards SBIR/STTR Highlights Reporting Fraud Contact Information Small Business Innovation Research and Small Business

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

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

    Highly Efficient Multigap Solar Cell Materials Lawrence Berkeley National Laboratory Contact LBL About This Technology Publications: PDF Document Publication Yu, K. M., Walukeiwicz, W., Wu J., Shan, W., Beeman, J. W., Scarpulla, M. A., Dubon, O. D., Becla, P. "Diluted II-VI Oxide Semiconductors with Multiple Band Gaps," Physical Review Letters, Vo. 91, No. 24, Dec. 12, 2003. (178 KB) Technology Marketing Summary Scientists at Berkeley Lab have invented multiband gap semiconducting

  18. Lithographic antennas for enhancement of solar cell efficiency

    SciTech Connect (OSTI)

    Kotter, D.K.; Boreman, G.

    1998-04-01

    This report documents proof-of-concept demonstration of the use of lithographic antennas for enhancement of solar-cell efficiency. A micro-sized lithographic antenna array was theoretically modeled, designed and fabricated. Experimental research was performed to validate the ability of the antenna array to concentrate infrared and visible energy onto photovoltaic (PV) materials. The research will serve as the basis for the design of a miniature power source for remote sensors.

  19. Encapsulant Material For Solar Cell Module And Laminated Glass Applications

    DOE Patents [OSTI]

    Hanoka, Jack I.; Klemchuk, Peter P.

    2001-02-13

    An encapsulant material includes a layer of metallocene polyethylene disposed between two layers of an acid copolymer of polyethylene. More specifically, the layer of metallocene polyethylene is disposed adjacent a rear surface of the first layer of the acid copolymer of polyethylene, and a second layer of the acid copolymer of polyethlene is disposed adjacent a rear surface of the layer of metallocene polyethylene. The encapsulant material can be used in solar cell module and laminated glass applications.

  20. Amorphous silicon cell array powered solar tracking apparatus

    DOE Patents [OSTI]

    Hanak, Joseph J.

    1985-01-01

    An array of an even number of amorphous silicon solar cells are serially connected between first and second terminals of opposite polarity. The terminals are connected to one input terminal of a DC motor whose other input terminal is connected to the mid-cell of the serial array. Vane elements are adjacent the end cells to selectively shadow one or the other of the end cells when the array is oriented from a desired attitude relative to the sun. The shadowing of one cell of a group of cells on one side of the mid-cell reduces the power of that group substantially so that full power from the group of cells on the other side of the mid-cell drives the motor to reorient the array to the desired attitude. The cell groups each have a full power output at the power rating of the motor. When the array is at the desired attitude the power output of the two groups of cells balances due to their opposite polarity so that the motor remains unpowered.