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Sample records for film solar cell

  1. 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. ...

  2. 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 ...

  3. 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.

  4. 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...

  5. Thin film cadmium telluride and zinc phosphide solar cells

    SciTech Connect (OSTI)

    Chu, T.

    1984-10-01

    This report describes research performed from June 1982 to October 1983 on the deposition of cadmium telluride films by direct combination of the cadmium and tellurium vapor on foreign substrates. Nearly stoichiometric p-type cadmium telluride films and arsenic-doped p-type films have been prepared reproducibly. Major efforts were directed to the deposition and characterization of heterojunction window materials, indium tin oxide, fluorine-doped tin oxide, cadmium oxide, and zinc oxide. A number of heterojunction solar cells were prepared, and the best thin-film ITO/CdTe solar cells had an AMl efficiency of about 7.2%. Zinc phosphide films were deposited on W/steel substrates by the reaction of zinc and phosphine in a hydrogen flow. Films without intentional doping had an electrical resistivity on the order of 10/sup 6/ ohm-cm, and this resistivity may be reduced to about 5 x 10/sup 4/ ohm-cm by adding hydrogen chloride or hydrogen bromide to the reaction mixture. Lower resistivity films were deposited by adding a controlled amount of silver nitrate solution on to the substrate surface. Major efforts were directed to the deposition of low-resistivity zinc selenide in order to prepare ZnSe/An/sub 3/P/sub 2/ heterojunction thin-film solar cells. However, zinc selenide films deposited by vacuum evaporation and chemical vapor deposition techniques were all of high resistivity.

  6. 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 ...

  7. 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 ...

  8. 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 ...

  9. 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.

  10. Optical and structural properties of sputtered CdS films for thin film solar cell applications

    SciTech Connect (OSTI)

    Kim, Donguk; Park, Young; Kim, Minha; Choi, Youngkwan; Park, Yong Seob; Lee, Jaehyoeng

    2015-09-15

    Graphical abstract: Photo current–voltage curves (a) and the quantum efficiency (QE) (b) for the solar cell with CdS film grown at 300 °C. - Highlights: • CdS thin films were grown by a RF magnetron sputtering method. • Influence of growth temperature on the properties of CdS films was investigated. • At higher T{sub g}, the crystallinity of the films improved and the grains enlarged. • CdS/CdTe solar cells with efficiencies of 9.41% were prepared at 300 °C. - Abstract: CdS thin films were prepared by radio frequency magnetron sputtering at various temperatures. The effects of growth temperature on crystallinity, surface morphology and optical properties of the films were characterized with X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Raman spectra, UV–visible spectrophotometry, and photoluminescence (PL) spectra. As the growth temperature was increased, the crystallinity of the sputtered CdS films was improved and the grains were enlarged. The characteristics of CdS/CdTe thin film solar cell appeared to be significantly influenced by the growth temperature of the CdS films. Thin film CdS/CdTe solar cells with efficiencies of 9.41% were prepared at a growth temperature of 300 °C.

  11. Ablation of film stacks in solar cell fabrication processes

    SciTech Connect (OSTI)

    Harley, Gabriel; Kim, Taeseok; Cousins, Peter John

    2013-04-02

    A dielectric film stack of a solar cell is ablated using a laser. The dielectric film stack includes a layer that is absorptive in a wavelength of operation of the laser source. The laser source, which fires laser pulses at a pulse repetition rate, is configured to ablate the film stack to expose an underlying layer of material. The laser source may be configured to fire a burst of two laser pulses or a single temporally asymmetric laser pulse within a single pulse repetition to achieve complete ablation in a single step.

  12. 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.

  13. Preparation Of Copper Indium Gallium Diselenide Films For Solar Cells

    DOE Patents [OSTI]

    Bhattacharya, Raghu N.; Contreras, Miguel A.; Keane, James; Tennant, Andrew L. , Tuttle, John R.; Ramanathan, Kannan; Noufi, Rommel

    1998-08-08

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

  14. Silicon-film{trademark} on ceramic solar cells. Final report

    SciTech Connect (OSTI)

    Hall, R.B.; Bacon, C.; DiReda, V.; Ford, D.H.; Ingram, A.E.; Lampo, S.M.; Rand, J.A.; Ruffins, T.R.; Barnett, A.M.

    1993-02-01

    The Silicon-Film{trademark} design achieves high performance through the use of a thin silicon layer. Optimally designed thin crystalline solar cells (<50 microns thick) have performance advantages over conventional thick devices. The enhancement in performance requires the incorporation of back-surface passivation and light trapping. The high-performance Silicon-Film{trademark} design employs a metallurgical barrier between the low-cost substrate and the thin silicon layer. The properties of the metallurgical barrier must be engineered to implement specific device requirements, such as high back-surface reflectivity. Recent advances in process development are described here.

  15. 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.

  16. 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.

  17. Methods for fabricating thin film III-V compound solar cell

    DOE Patents [OSTI]

    Pan, Noren; Hillier, Glen; Vu, Duy Phach; Tatavarti, Rao; Youtsey, Christopher; McCallum, David; Martin, Genevieve

    2011-08-09

    The present invention utilizes epitaxial lift-off in which a sacrificial layer is included in the epitaxial growth between the substrate and a thin film III-V compound solar cell. To provide support for the thin film III-V compound solar cell in absence of the substrate, a backing layer is applied to a surface of the thin film III-V compound solar cell before it is separated from the substrate. To separate the thin film III-V compound solar cell from the substrate, the sacrificial layer is removed as part of the epitaxial lift-off. Once the substrate is separated from the thin film III-V compound solar cell, the substrate may then be reused in the formation of another thin film III-V compound solar cell.

  18. New Selection Metric for Design of Thin-Film Solar Cell Absorber...

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

    Maximum Efficiency (SLME) is a new and calculable selection metric to identify new andor improved photovoltaic (PV) absorber candidate materials for thin- film solar cells. ...

  19. Junction Evolution During Fabrication of CdS/CdTe Thin-film PV Solar Cells (Presentation)

    SciTech Connect (OSTI)

    Gessert, T. A.

    2010-09-01

    Discussion of the formation of CdTe thin-film PV junctions and optimization of CdTe thin-film PV solar cells.

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

    SciTech Connect (OSTI)

    Not Available

    2012-09-01

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

  1. Efficiency calculations of thin-film GaAs solar cells on Si substrates

    SciTech Connect (OSTI)

    Yamaguchi, M.; Amano, C.

    1985-11-01

    Dislocation effect upon the efficiency of single-crystal thin-film AlGaAs-GaAs heteroface solar cells on Si substrates is analyzed. Solar-cell properties are calculated based on a simple model; in the model, dislocations act as recombination centers to reduce the minority-carrier diffusion length in each layer and increase the space-charge layer recombination current. Numerical analysis is also carried out to optimize thin-film AlGaAs-GaAs heteroface solar-cell structures. The fabrication of thin-film AlGaAs-GaAs heteroface solar cells with a practical efficiency larger than 18% on Si substrates appears possible if the dislocation density in the thin-film GaAs layer is less than 10/sup 6/ cm/sup -2/.

  2. Record Makes Thin-Film Solar Cell Competitive with Silicon Efficiency...

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

    Record Makes Thin-Film Solar Cell Competitive with Silicon Efficiency March 24, 2008 Researchers at the U.S. Department of Energy's National Renewable Energy Laboratory have moved ...

  3. NREL and Company Researchers Team Up on Thin-Film Solar Cells...

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

    NREL and Company Researchers Team Up on Thin-Film Solar Cells November 12, 2003 Golden, Colo. - An Austin, Tex.-based company is moving toward commercial production of advanced ...

  4. Efficiency considerations for polycrystalline GaAs thin-film solar cells

    SciTech Connect (OSTI)

    Yamaguchi, M.; Itoh, Y.

    1986-07-01

    The effect of grain boundaries upon the efficiency of polycrystalline GaAs thin-film solar cells is analyzed. Solar-cell properties are calculated on a simple model where grain boundaries act as recombination centers to reduce the minority-carrier diffusion length in the solar cell's active layer and increase the space-charge layer recombination current. An effective diffusion length is expressed in terms of grain size, allowing the calculation of short-circuit current density and open-circuit voltage. Excellent agreement is obtained between theory and experiment. The fabrication of thin-film GaAs solar cells with an efficiency greater than 18% appears to be possible if the grain size in the thin-film GaAs layer with thickness of 3 ..mu..m is larger than 1000 ..mu..m.

  5. 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.

  6. Radiation damage of GaAs thin-film solar cells on Si substrates

    SciTech Connect (OSTI)

    Itoh, Y.; Yamaguchi, M.; Nishioka, T.; Yamamoto, A.

    1987-01-15

    1-MeV electron irradiation damages in GaAs thin-film solar cells on Si substrates are examined for the first time. Damage constant for minority-carrier diffusion length in GaAs heteroepitaxial films on Si substrates is found to be the same as that in GaAs homoepitaxial films on GaAs substrates. This agreement suggests that GaAs/Si has the same defect introduction rate with radiation as GaAs/GaAs. The degradation of GaAs solar cells on Si with electron irradiation is less than that of GaAs solar cells on GaAs, because in the present, GaAs films on Si substrates have lower minority-carrier diffusion length compared to GaAs films on GaAs and these films are insensitive to radiation. The p/sup +/-p/sup +/-n AlGaAs-GaAs heteroface solar cell with junction depth of about 0.3 ..mu..m is concluded to be useful for a high-efficiency and radiation-resistant solar cell fabricated on a Si substrate.

  7. Thin film polycrystalline silicon: Promise and problems in displays and solar cells

    SciTech Connect (OSTI)

    Fonash, S.J.

    1995-08-01

    Thin film polycrystalline Si (poly-Si) with its carrier mobilities, potentially good stability, low intragrain defect density, compatibility with silicon processing, and ease of doping activation is an interesting material for {open_quotes}macroelectronics{close_quotes} applications such as TFTs for displays and solar cells. The poly-Si films needed for these applications can be ultra-thin-in the 500{Angstrom} to 1000{Angstrom} thickness range for flat panel display TFTs and in the 4{mu}m to 10{mu}m thickness range for solar cells. Because the films needed for these microelectronics applications can be so thin, an effective approach to producing the films is that of crystallizing a-Si precursor material. Unlike cast materials, poly-Si films made this way can be produced using low temperature processing. Unlike deposited poly-Si films, these crystallized poly-Si films can have grain widths that are much larger than the film thickness and almost atomically smooth surfaces. This thin film poly-Si crystallized from a-Si precursor films, and its promise and problems for TFTs and solar cells, is the focus of this discussion.

  8. Thin film cadmium telluride, zinc telluride, and mercury zinc telluride solar cells

    SciTech Connect (OSTI)

    Chu, T.L. )

    1992-04-01

    This report describes research to demonstrate (1) thin film cadmium telluride solar cells with a quantum efficiency of 75% or higher at 0. 44 {mu}m and a photovoltaic efficiency of 11.5% or greater, and (2) thin film zinc telluride and mercury zinc telluride solar cells with a transparency to sub-band-gap radiation of 65% and a photovoltaic conversion efficiency of 5% and 8%, respectively. Work was directed at (1) depositing transparent conducting semiconductor films by solution growth and metal-organic chemical vapor deposition (MOCVD) technique, (2) depositing CdTe films by close-spaced sublimation (CSS) and MOCVD techniques, (3) preparing and evaluating thin film CdTe solar cells, and (4) preparing and characterizing thin film ZnTe, CD{sub 1-x}Zn{sub 1-x}Te, and Hg{sub 1-x}Zn{sub x}Te solar cells. The deposition of CdS films from aqueous solutions was investigated in detail, and their crystallographic, optical, and electrical properties were characterized. CdTe films were deposited from DMCd and DIPTe at 400{degrees}C using TEGa and AsH{sub 3} as dopants. CdTe films deposited by CSS had significantly better microstructures than those deposited by MOCVD. Deep energy states in CdTe films deposited by CSS and MOCVD were investigated. Thin films of ZnTe, Cd{sub 1- x}Zn{sub x}Te, and Hg{sub 1-x}Zn{sub x}Te were deposited by MOCVD, and their crystallographic, optical, and electrical properties were characterized. 67 refs.

  9. Thin film GaAs solar cells on glass substrates by epitaxial liftoff

    SciTech Connect (OSTI)

    Lee, X.Y.; Goertemiller, M.; Boroditsky, M.; Ragan, R.; Yablonovitch, E.

    1997-02-01

    In this work, we describe the fabrication and operating characteristics of GaAs/AlGaAs thin film solar cells processed by the epitaxial liftoff (ELO) technique. This technique allows the transfer of these cells onto glass substrates. The performance of the lifted-off solar cell is demonstrated by means of electrical measurements under both dark and illuminated conditions. We have also optimized the light trapping conditions in this direct-gap material. The results show that good solar absorption is possible in active layers as thin as 0.32 {mu}m. In such a thin solar cell, the open circuit voltage would be enhanced. We believe that the combination of an epitaxial liftoff thin GaAs film, and nano-texturing can lead to record breaking performance. {copyright} {ital 1997 American Institute of Physics.}

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

    SciTech Connect (OSTI)

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

    2012-06-11

    Tandem solar cells (TSCs), which use two or more materials to absorb sunlight, have achieved power conversion efficiencies of >25% versus 11-20% for commercialized single junction solar cell modules. The key to widespread commercialization of TSCs is to develop the wide-band, top solar cell that is both cheap to fabricate and has a high open-circuit voltage (i.e. >1V). Previous work in TSCs has generally focused on using expensive processing techniques with slow growth rates resulting in costs that are two orders of magnitude too expensive to be used in conventional solar cell modules. The objective of the PLANT PV proposal was to investigate the feasibility of using Ag(In,Ga)Se2 (AIGS) as the wide-bandgap absorber in the top cell of a thin film tandem solar cell (TSC). Despite being studied by very few in the solar community, AIGS solar cells have achieved one of the highest open-circuit voltages within the chalcogenide material family with a Voc of 949mV when grown with an expensive processing technique (i.e. Molecular Beam Epitaxy). PLANT PVâ??s goal in Phase I of the DOE SBIR was to 1) develop the chemistry to grow AIGS thin films via solution processing techniques to reduce costs and 2) fabricate new device architectures with high open-circuit voltage to produce full tandem solar cells in Phase II. PLANT PV attempted to translate solution processing chemistries that were successful in producing >12% efficient Cu(In,Ga)Se2 solar cells by replacing copper compounds with silver. The main thrust of the research was to determine if it was possible to make high quality AIGS thin films using solution processing and to fully characterize the materials properties. PLANT PV developed several different types of silver compounds in an attempt to fabricate high quality thin films from solution. We found that silver compounds that were similar to the copper based system did not result in high quality thin films. PLANT PV was able to deposit AIGS thin films using a

  11. Thin-film solar cell fabricated on a flexible metallic substrate

    DOE Patents [OSTI]

    Tuttle, John R.; Noufi, Rommel; Hasoon, Falah S.

    2006-05-30

    A thin-film solar cell (10) is provided. The thin-film solar cell (10) comprises a flexible metallic substrate (12) having a first surface and a second surface. A back metal contact layer (16) is deposited on the first surface of the flexible metallic substrate (12). A semiconductor absorber layer (14) is deposited on the back metal contact. A photoactive film deposited on the semiconductor absorber layer (14) forms a heterojunction structure and a grid contact (24) deposited on the heterjunction structure. The flexible metal substrate (12) can be constructed of either aluminium or stainless steel. Furthermore, a method of constructing a solar cell is provided. The method comprises providing an aluminum substrate (12), depositing a semiconductor absorber layer (14) on the aluminum substrate (12), and insulating the aluminum substrate (12) from the semiconductor absorber layer (14) to inhibit reaction between the aluminum substrate (12) and the semiconductor absorber layer (14).

  12. Thin-Film Solar Cell Fabricated on a Flexible Metallic Substrate

    DOE Patents [OSTI]

    Tuttle, J. R.; Noufi, R.; Hasoon, F. S.

    2006-05-30

    A thin-film solar cell (10) is provided. The thin-film solar cell (10) comprises a flexible metallic substrate (12) having a first surface and a second surface. A back metal contact layer (16) is deposited on the first surface of the flexible metallic substrate (12). A semiconductor absorber layer (14) is deposited on the back metal contact. A photoactive film deposited on the semiconductor absorber layer (14) forms a heterojunction structure and a grid contact (24) deposited on the heterjunction structure. The flexible metal substrate (12) can be constructed of either aluminium or stainless steel. Furthermore, a method of constructing a solar cell is provided. The method comprises providing an aluminum substrate (12), depositing a semiconductor absorber layer (14) on the aluminum substrate (12), and insulating the aluminum substrate (12) from the semiconductor absorber layer (14) to inhibit reaction between the aluminum substrate (12) and the semiconductor absorber layer (14).

  13. CIGS Thin-Film Solar Cell Research at NREL: FY04 Results and

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

    Accomplishments (Conference) | SciTech Connect 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 Accomplishments × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of DOE's Office of Scientific and Technical Information (OSTI) and is provided as a public service. Visit OSTI to utilize additional

  14. Real time intelligent process control system for thin film solar cell manufacturing

    SciTech Connect (OSTI)

    George Atanasoff

    2010-10-29

    This project addresses the problem of lower solar conversion efficiency and waste in the typical solar cell manufacturing process. The work from the proposed development will lead toward developing a system which should be able to increase solar panel conversion efficiency by an additional 12-15% resulting in lower cost panels, increased solar technology adoption, reduced carbon emissions and reduced dependency on foreign oil. All solar cell manufacturing processes today suffer from manufacturing inefficiencies that currently lead to lower product quality and lower conversion efficiency, increased product cost and greater material and energy consumption. This results in slower solar energy adoption and extends the time solar cells will reach grid parity with traditional energy sources. The thin film solar panel manufacturers struggle on a daily basis with the problem of thin film thickness non-uniformity and other parameters variances over the deposited substrates, which significantly degrade their manufacturing yield and quality. Optical monitoring of the thin films during the process of the film deposition is widely perceived as a necessary step towards resolving the non-uniformity and non-homogeneity problem. In order to enable the development of an optical control system for solar cell manufacturing, a new type of low cost optical sensor is needed, able to acquire local information about the panel under deposition and measure its local characteristics, including the light scattering in very close proximity to the surface of the film. This information cannot be obtained by monitoring from outside the deposition chamber (as traditional monitoring systems do) due to the significant signal attenuation and loss of its scattering component before the reflected beam reaches the detector. In addition, it would be too costly to install traditional external in-situ monitoring systems to perform any real-time monitoring over large solar panels, since it would require

  15. Radiation resistance of thin-film solar cells for space photovoltaic power

    SciTech Connect (OSTI)

    Woodyard, J.R.; Landis, G.A.

    1991-01-01

    Copper indium diselenide, cadmium telluride, and amorphous silicon alloy solar cells have achieved noteworthy performance and are currently being studied for space power applications. Cadmium sulfide cells had been the subject of much effort but are no longer considered for space applications. A review is presented of what is known about the radiation degradation of thin film solar cells in space. Experimental cadmium telluride and amorphous silicon alloy cells are reviewed. Damage mechanisms and radiation induced defect generation and passivation in the amorphous silicon alloy cell are discussed in detail due to the greater amount of experimental data available.

  16. Method and apparatus for fabricating a thin-film solar cell utilizing a hot wire chemical vapor deposition technique

    DOE Patents [OSTI]

    Wang, Qi; Iwaniczko, Eugene

    2006-10-17

    A thin-film solar cell is provided. The thin-film solar cell comprises an a-SiGe:H (1.6 eV) n-i-p solar cell having a deposition rate of at least ten (10) .ANG./second for the a-SiGe:H intrinsic layer by hot wire chemical vapor deposition. A method for fabricating a thin film solar cell is also provided. The method comprises depositing a n-i-p layer at a deposition rate of at least ten (10) .ANG./second for the a-SiGe:H intrinsic layer.

  17. Method of forming particulate materials for thin-film solar cells

    DOE Patents [OSTI]

    Eberspacher, Chris; Pauls, Karen Lea

    2004-11-23

    A method for preparing particulate materials useful in fabricating thin-film solar cells is disclosed. Particulate materials is prepared by the method include for example materials comprising copper and indium and/or gallium in the form of single-phase, mixed-metal oxide particulates; multi-phase, mixed-metal particulates comprising a metal oxide; and multinary metal particulates.

  18. Processing and modeling issues for thin-film solar cell devices. Final report

    SciTech Connect (OSTI)

    Birkmire, R.W.; Phillips, J.E.

    1997-11-01

    During the third phase of the subcontract, IEC researchers have continued to provide the thin film PV community with greater depth of understanding and insight into a wide variety of issues including: the deposition and characterization of CuIn{sub 1-x}Ga{sub x}Se{sub 2}, a-Si, CdTe, CdS, and TCO thin films; the relationships between film and device properties; and the processing and analysis of thin film PV devices. This has been achieved through the systematic investigation of all aspects of film and device production and through the analysis and quantification of the reaction chemistries involved in thin film deposition. This methodology has led to controlled fabrications of 15% efficient CuIn{sub 1-x}Ga{sub x}Se{sub 2} solar cells over a wide range of Ga compositions, improved process control of the fabrication of 10% efficient a-Si solar cells, and reliable and generally applicable procedures for both contacting and doping films. Additional accomplishments are listed below.

  19. Systems and methods for solar cells with CIS and CIGS films made by reacting evaporated copper chlorides with selenium

    SciTech Connect (OSTI)

    Albin, David S.; Noufi, Rommel

    2015-06-09

    Systems and methods for solar cells with CIS and CIGS films made by reacting evaporated copper chlorides with selenium are provided. In one embodiment, a method for fabricating a thin film device comprises: providing a semiconductor film comprising indium (In) and selenium (Se) upon a substrate; heating the substrate and the semiconductor film to a desired temperature; and performing a mass transport through vapor transport of a copper chloride vapor and se vapor to the semiconductor film within a reaction chamber.

  20. PEDOT:PSS emitters on multicrystalline silicon thin-film absorbers for hybrid solar cells

    SciTech Connect (OSTI)

    Junghanns, Marcus; Plentz, Jonathan Andrä, Gudrun; Gawlik, Annett; Höger, Ingmar; Falk, Fritz

    2015-02-23

    We fabricated an efficient hybrid solar cell by spin coating poly(3,4-ethylene-dioxythiophene):polystyrenesulfonate (PEDOT:PSS) on planar multicrystalline Si (mc-Si) thin films. The only 5 μm thin Si absorber layers were prepared by diode laser crystallization of amorphous Si deposited by electron beam evaporation on glass. On these absorber layers, we studied the effect of SiO{sub x} and Al{sub 2}O{sub 3} terminated Si surfaces. The short circuit density and power conversion efficiency (PCE) of the mc-Si/Al{sub 2}O{sub 3}/PEDOT:PSS solar cell increase from 20.6 to 25.4 mA/cm{sup 2} and from 7.3% to 10.3%, respectively, as compared to the mc-Si/SiO{sub x}/PEDOT:PSS cell. Al{sub 2}O{sub 3} lowers the interface recombination and improves the adhesion of the polymer film on the hydrophobic mc-Si thin film. Open circuit voltages up to 604 mV were reached. This study demonstrates the highest PCE so far of a hybrid solar cell with a planar thin film Si absorber.

  1. Polycrystalline GaAs solar cells on low-cost Silicon-Film{trademark} substrates

    SciTech Connect (OSTI)

    Mauk, M.G.; Feyock, B.W.; Hall, R.B.; Cavanaugh, K.D.; Cotter, J.E.

    1997-12-31

    The authors assess the potential of a low-cost, large-area Silicon-Film{trademark} sheet as a substrate for thin-film polycrystalline GaAs solar cells. Silicon-Film is a relatively inexpensive material on which large-grain (>2 mm) polycrystalline GaAs films can be formed. The GaAs epitaxial layers are grown by a simple close-spaced vapor transport (CSVT) technique using water vapor as a transport agent. A recrystallized Ge{sub 1{minus}x}Si{sub x} buffer layer between the GaAs epilayer and Silicon-Film substrate can facilitate growth of the GaAs. Selective epitaxy on patterned, oxide-masked substrates is effective in reducing thermal stress effects.

  2. Characterization of the Electronic and Chemical Structure at the Thin Film Solar Cell Interfaces: June 2005 -- June 2009

    SciTech Connect (OSTI)

    Heske, C.

    2009-09-01

    Study using photoelectron spectroscopy, inverse photoemission, and X-ray absorption and emission to derive the electronic structure of interfaces in CIGSS and CdTe thin-film solar cells.

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

    SciTech Connect (OSTI)

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

    2000-01-04

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

  4. Group I-III-VI.sub.2 semiconductor films for solar cell application

    DOE Patents [OSTI]

    Basol, Bulent M.; Kapur, Vijay K.

    1991-01-01

    This invention relates to an improved thin film solar cell with excellent electrical and mechanical integrity. The device comprises a substrate, a Group I-III-VI.sub.2 semiconductor absorber layer and a transparent window layer. The mechanical bond between the substrate and the Group I-III-VI.sub.2 semiconductor layer is enhanced by an intermediate layer between the substrate and the Group I-III-VI.sub.2 semiconductor film being grown. The intermediate layer contains tellurium or substitutes therefor, such as Se, Sn, or Pb. The intermediate layer improves the morphology and electrical characteristics of the Group I-III-VI.sub.2 semiconductor layer.

  5. InGaN-based thin film solar cells: Epitaxy, structural design, and photovoltaic properties

    SciTech Connect (OSTI)

    Sang, Liwen; Liao, Meiyong; Koide, Yasuo; Sumiya, Masatomo

    2015-03-14

    In{sub x}Ga{sub 1−x}N, with the tunable direct bandgaps from ultraviolet to near infrared region, offers a promising candidate for the high-efficiency next-generation thin-film photovoltaic applications. Although the adoption of thick InGaN film as the active region is desirable to obtain efficient light absorption and carrier collection compared to InGaN/GaN quantum wells structure, the understanding on the effect from structural design is still unclear due to the poor-quality InGaN films with thickness and difficulty of p-type doping. In this paper, we comprehensively investigate the effects from film epitaxy, doping, and device structural design on the performances of the InGaN-based solar cells. The high-quality InGaN thick film is obtained on AlN/sapphire template, and p-In{sub 0.08}Ga{sub 0.92}N is achieved with a high hole concentration of more than 10{sup 18 }cm{sup −3}. The dependence of the photovoltaic performances on different structures, such as active regions and p-type regions is analyzed with respect to the carrier transport mechanism in the dark and under illumination. The strategy of improving the p-i interface by using a super-thin AlN interlayer is provided, which successfully enhances the performance of the solar cells.

  6. Progress in thin film solar photovoltaic technologies

    SciTech Connect (OSTI)

    Ullal, H.S.; Zweibel, K.; Mitchell, R.L. )

    1991-01-01

    This paper focuses on the rapid recent advances made by thin film solar cell technologies, namely, amorphous silicon, copper indium diselenide, and cadmium telluride. It also indicates the several advantages of thin films. Various consumer products and power applications using thin film solar cells are also discussed. The increasing interest among the utilities for PV system applications is also elucidated.

  7. Electrochemical solar cells using CdSe thin film electrodes

    SciTech Connect (OSTI)

    Xiao, Xu-Rui; Tien, H.Ti.

    1983-01-01

    Electrochemical photocells consisting of a CdSe thin film anode and a Pt cathode immersed in 1M Na/sub 2/S-NaOH-S solution have been studied. CdSe thin films were formed on Ti, Cr, Mo, SnO/sub 2/, glassy carbon, and graphite substrates by coating an aqueous mixture of CdSe, ZnCl/sub 2/, and surfactant, subsequently sintering at 400/sup 0/-500/sup 0/C in air. The current-voltage (I-V) relations, output power efficiency, open-circuit voltage, and short-circuit current were measured. Seven percent power conversion efficiency was obtained at 20 mW/cm/sup 2/ light intensity after photoetching. The monochromatic I-V curves were analyzed.

  8. Thin films and solar cells of cadmium telluride and cadmium zinc telluride

    SciTech Connect (OSTI)

    Ferekides, C.S.

    1991-01-01

    The objectives of this dissertation are to investigate (1) the metalorganic chemical vapor deposition (MOCVD) and properties of cadmium telluride (CdTe) and cadmium zinc telluride (Cd(1-x)Zn(z)Te) films and junctions, and their potential application to solar cells, and (2) the fabrication and characterization of CdTe solar cells by the close spaced sublimation (CSS) technique. CdTe and Cd(1-x)Zn(x)Te films have been deposited by MOCVD on a variety of substrates at 300-400 C.The effect of the deposition parameters and post deposition heat treatments on the electrical, optical, and structural properties have been investigated. Heterojunctions of the configuration CdTe/transparent conducting semiconductor (TCS) and Cd(1-x)Zn(x)Te/TCS have been prepared and characterized. CdTe(MOCVD)/CdS and Cd(1-x)Zn(x)Te(E sub g = 1.65eV)/Cd(1-x)Zn(x)S solar cells with efficiencies of 9.9 percent and 2.4 percent, respectively have been fabricated. The as-deposited CdTe(MOCVD)/CdS junctions exhibited high dark current densities due to deflects at the interface associated with small grain size. No effective post-deposition heat treatment has been developed. CdTe/CdS solar cells have also been fabricated by the close spaced sublimation (CSS). Significant improvements in material and processing have been made, and in collaboration with fellow researchers an AM1.5 conversion efficiency of 13.4 percent has been demonstrated, the highest efficiency ever measured for such devices. The highest conversion efficiency for the CdTe(CSS)/CdS solar cell was achieved by reaching high open-circuit voltages and fill factors, while the short-circuit current densities were moderate. These results indicate that further improvements to increase the short-circuit current densities can result in conversion efficiencies over 15 percent.

  9. Low resistance thin film organic solar cell electrodes

    DOE Patents [OSTI]

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

    2008-01-01

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

  10. 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.

  11. Back contact buffer layer for thin-film solar cells

    DOE Patents [OSTI]

    Compaan, Alvin D.; Plotnikov, Victor V.

    2014-09-09

    A photovoltaic cell structure is disclosed that includes a buffer/passivation layer at a CdTe/Back contact interface. The buffer/passivation layer is formed from the same material that forms the n-type semiconductor active layer. In one embodiment, the buffer layer and the n-type semiconductor active layer are formed from cadmium sulfide (CdS). A method of forming a photovoltaic cell includes the step of forming the semiconductor active layers and the buffer/passivation layer within the same deposition chamber and using the same material source.

  12. Light trapping in thin-film solar cells measured by Raman spectroscopy

    SciTech Connect (OSTI)

    Ledinský, M.; Moulin, E.; Bugnon, G.; Meillaud, F.; Ballif, C.; Ganzerová, K.; Vetushka, A.; Fejfar, A.

    2014-09-15

    In this study, Raman spectroscopy is used as a tool to determine the light-trapping capability of textured ZnO front electrodes implemented in microcrystalline silicon (μc-Si:H) solar cells. Microcrystalline silicon films deposited on superstrates of various roughnesses are characterized by Raman micro-spectroscopy at excitation wavelengths of 442 nm, 514 nm, 633 nm, and 785 nm, respectively. The way to measure quantitatively and with a high level of reproducibility the Raman intensity is described in details. By varying the superstrate texture and with it the light trapping in the μc-Si:H absorber layer, we find significant differences in the absolute Raman intensity measured in the near infrared wavelength region (where light trapping is relevant). A good agreement between the absolute Raman intensity and the external quantum efficiency of the μc-Si:H solar cells is obtained, demonstrating the validity of the introduced method. Applications to thin-film solar cells, in general, and other optoelectronic devices are discussed.

  13. Method and making group IIB metal - telluride films and solar cells

    DOE Patents [OSTI]

    Basol, Bulent M.; Kapur, Vijay K.

    1990-08-21

    A technique is disclosed forming thin films (13) of group IIB metal-telluride, such as Cd.sub.x Zn.sub.1-x Te (0.ltoreq.x.ltoreq.1), on a substrate (10) which comprises depositing Te (18) and at least one of the elements (19) of Cd, Zn, and Hg onto a substrate and then heating the elements to form the telluride. A technique is also provided for doping this material by chemically forming a thin layer of a dopant on the surface of the unreacted elements and then heating the elements along with the layer of dopant. A method is disclosed of fabricating a thin film photovoltaic cell which comprises depositing Te and at least one of the elements of Cd, Zn, and Hg onto a substrate which contains on its surface a semiconductor film (12) and then heating the elements in the presence of a halide of the Group IIB metals, causing the formation of solar cell grade Group IIB metal-telluride film and also causing the formation of a rectifying junction, in situ, between the semiconductor film on the substrate and the Group IIB metal-telluride layer which has been formed.

  14. Highly efficient ultrathin-film amorphous silicon solar cells on top of imprinted periodic nanodot arrays

    SciTech Connect (OSTI)

    Yan, Wensheng Gu, Min; Tao, Zhikuo; Ong, Thiam Min Brian

    2015-03-02

    The addressing of the light absorption and conversion efficiency is critical to the ultrathin-film hydrogenated amorphous silicon (a-Si:H) solar cells. We systematically investigate ultrathin a-Si:H solar cells with a 100 nm absorber on top of imprinted hexagonal nanodot arrays. Experimental evidences are demonstrated for not only notable silver nanodot arrays but also lower-cost ITO and Al:ZnO nanodot arrays. The measured external quantum efficiency is explained by the simulation results. The J{sub sc} values are 12.1, 13.0, and 14.3 mA/cm{sup 2} and efficiencies are 6.6%, 7.5%, and 8.3% for ITO, Al:ZnO, and silver nanodot arrays, respectively. Simulated optical absorption distribution shows high light trapping within amorphous silicon layer.

  15. Three-junction solar cells comprised of a thin-film GaInP/GaAs tandem cell mechanically stacked on a Si cell

    SciTech Connect (OSTI)

    Yazawa, Y.; Tamura, K.; Watahiki, S.; Kitatani, T.; Ohtsuka, H.; Warabisako, T.

    1997-12-31

    Three-junction tandem solar cells were fabricated by mechanical stacking of a thin-film GaInP/GaAs monolithic tandem cell and a Si cell. The epitaxial lift-off (ELO) technique was used for the thinning of GaInP/GaAs tandem cells. Both spectral responses of the GaInP top cell and the GaAs middle cell in the thin-film GaInP/GaAs monolithic tandem cell were conserved. The Si cell performance has been improved by reducing the absorption loss in the GaAs substrate.

  16. Electrophoretic deposited TiO2 pigment-based back reflectors for thin film solar cells

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

    Bills, Braden; Morris, Nathan; Dubey, Mukul; Wang, Qi; Fan, Qi Hua

    2015-01-16

    Highly reflective coatings with strong light scattering effect have many applications in optical components and optoelectronic devices. This paper reports titanium dioxide (TiO2) pigment-based reflectors that have 2.5 times higher broadband diffuse reflection than commercially produced aluminum or silver based reflectors and result in efficiency enhancements of a single-junction amorphous Si solar cell. Electrophoretic deposition is used to produce pigment-based back reflectors with high pigment density, controllable film thickness and site-specific deposition. Electrical conductivity of the pigment-based back reflectors is improved by creating electrical vias throughout the pigment-based back reflector by making holes using an electrical discharge / dielectric breakdownmore » approach followed by a second electrophoretic deposition of conductive nanoparticles into the holes. While previous studies have demonstrated the use of pigment-based back reflectors, for example white paint, on glass superstrate configured thin film Si solar cells, this work presents a scheme for producing pigment-based reflectors on complex shape and flexible substrates. Finally, mechanical durability and scalability are demonstrated on a continuous electrophoretic deposition roll-to-roll system which has flexible metal substrate capability of 4 inch wide and 300 feet long.« less

  17. Development of Commercial Technology for Thin Film Silicon Solar Cells on Glass: Cooperative Research and Development Final Report, CRADA Number CRD-07-209

    SciTech Connect (OSTI)

    Sopori, B.

    2013-03-01

    NREL has conducted basic research relating to high efficiency, low cost, thin film silicon solar cell design and the method of making solar cells. Two patents have been issued to NREL in the above field. In addition, specific process and metrology tools have been developed by NREL. Applied Optical Sciences Corp. (AOS) has expertise in the manufacture of solar cells and has developed its own unique concentrator technology. AOS wants to complement its solar cell expertise and its concentrator technology by manufacturing flat panel thin film silicon solar cell panels. AOS wants to take NREL's research to the next level, using it to develop commercially viable flat pane, thin film silicon solar cell panels. Such a development in equipment, process, and metrology will likely produce the lowest cost solar cell technology for both commercial and residential use. NREL's fundamental research capability and AOS's technology and industrial background are complementary to achieve this product development.

  18. Progress in thin film solar photovoltaic technologies

    SciTech Connect (OSTI)

    Ullal, H.S.; Zweibel, K.

    1989-12-01

    This paper focuses on the rapid recent advances made by thin film solar cell technologies, namely, amorphous silicon, copper indium diselenide, and cadmium telluride. It also indicates the several advantages of thin films. Various consumer products and power applications using thin film solar cells are also discussed. The increasing interest among the utilities for PV system applications is also elucidated. 29 refs., 8 figs., 3 tabs.

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

    SciTech Connect (OSTI)

    Morel, D.L.; Ferekides, C.S.

    1994-07-01

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

  20. Large-area Silicon-Film{trademark} panels and solar cells. Final technical report, July 1995--March 1998

    SciTech Connect (OSTI)

    Rand, J.A.; Bai, Y.; Barnett, A.M.; Culik, J.S.; Ford, D.H.; Hall, R.B.; Kendall, C.L.

    1998-09-01

    This report will detail substantial improvements in each of the task areas. A number of new products were developed, including a 130 kW array built using a new panel design. Improvements in laboratory-scale solar cell processing resulted in a confirmed efficiency of 16.6%. A new Silicon-Film{trademark} production sheet machine was built which increased throughput by 70%. Three solar cell fabrication processes were converted from low throughout batch processes to high throughput, continuous, belt processes. These new processes are capable of processing sheet over 31 cm in width. Finally, a new Silicon-Film{trademark} sheet machine was built that demonstrated a sheet width of 38 cm. This tool enabled AstroPower to demonstrate a wide range of solar cell sizes, many of which have generated considerable market interest.

  1. Hybrid ZnO nanowire/a-Si:H thin-film radial junction solar cells using nanoparticle front contacts

    SciTech Connect (OSTI)

    Pathirane, M. Iheanacho, B.; Lee, C.-H.; Wong, W. S.; Tamang, A.; Knipp, D.; Lujan, R.

    2015-10-05

    Hydrothermally synthesized disordered ZnO nanowires were conformally coated with a-Si:H thin-films to fabricate three dimensional hybrid nanowire/thin-film structures. The a-Si:H layer formed a radial junction p-i-n diode solar cell around the ZnO nanowire. The cylindrical hybrid solar cells enhanced light scattering throughout the UV-visible-NIR spectrum (300 nm–800 nm) resulting in a 22% increase in short-circuit current density compared to the reference planar p-i-n device. A fill factor of 69% and a total power conversion efficiency of 6.5% were achieved with the hybrid nanowire solar cells using a spin-on indium tin oxide nanoparticle suspension as the top contact.

  2. Enhanced optoelectronic quality of perovskite thin films with hypophosphorous acid for planar heterojunction solar cells

    SciTech Connect (OSTI)

    Zhang, Wei; Pathak, Sandeep; Sakai, Nobuya; Stergiopoulos, Thomas; Nayak, Pabitra K.; Noel, Nakita K.; Haghighirad, Amir A.; Burlakov, Victor M.; deQuilettes, Dane W.; Sadhanala, Aditya; Li, Wenzhe; Wang, Liduo; Ginger, David S.; Friend, Richard H.; Snaith, Henry J.

    2015-11-30

    Solution-processed metal halide perovskite semiconductors, such as CH3NH3PbI3, have exhibited remarkable performance in solar cells, despite having non-negligible density of defect states. A likely candidate is halide vacancies within the perovskite crystals, or the presence of metallic lead, both generated due to the imbalanced I/Pb stoichiometry which could evolve during crystallization. Herein, we show that the addition of hypophosphorous acid (HPA) in the precursor solution can significantly improve the film quality, both electronically and topologically, and enhance the photoluminescence intensity, which leads to more efficient and reproducible photovoltaic devices. We demonstrate that the HPA can reduce the oxidized I2 back into I-, and our results indicate that this facilitates an improved stoichiometry in the perovskite crystal and a reduced density of metallic lead.

  3. Enhanced optoelectronic quality of perovskite thin films with hypophosphorous acid for planar heterojunction solar cells

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

    Zhang, Wei; Pathak, Sandeep; Sakai, Nobuya; Stergiopoulos, Thomas; Nayak, Pabitra K.; Noel, Nakita K.; Haghighirad, Amir A.; Burlakov, Victor M.; deQuilettes, Dane W.; Sadhanala, Aditya; et al

    2015-11-30

    Solution-processed metal halide perovskite semiconductors, such as CH3NH3PbI3, have exhibited remarkable performance in solar cells, despite having non-negligible density of defect states. A likely candidate is halide vacancies within the perovskite crystals, or the presence of metallic lead, both generated due to the imbalanced I/Pb stoichiometry which could evolve during crystallization. Herein, we show that the addition of hypophosphorous acid (HPA) in the precursor solution can significantly improve the film quality, both electronically and topologically, and enhance the photoluminescence intensity, which leads to more efficient and reproducible photovoltaic devices. We demonstrate that the HPA can reduce the oxidized I2 backmore » into I-, and our results indicate that this facilitates an improved stoichiometry in the perovskite crystal and a reduced density of metallic lead.« less

  4. Polycrystalline thin-film cadmium telluride solar cells fabricated by electrodeposition. Annual technical report

    SciTech Connect (OSTI)

    Trefny, J.U.; Mao, D.

    1998-01-01

    During the past year, Colorado School of Mines (CSM) researchers performed systematic studies of the growth and properties of electrodeposition CdS and back-contact formation using Cu-doped ZnTe, with an emphasis on low Cu concentrations. CSM also started to explore the stability of its ZnTe-Cu contacted CdTe solar cells. Researchers investigated the electrodeposition of CdS and its application in fabricating CdTe/CdS solar cells. The experimental conditions they explored in this study were pH from 2.0 to 3.0; temperatures of 80 and 90 C; CdCl{sub 2} concentration of 0.2 M; deposition potential from {minus}550 to {minus}600 mV vs. Ag/AgCl electrode; [Na{sub 2}S{sub 2}O{sub 4}] concentration between 0.005 and 0.05 M. The deposition rate increases with increase of the thiosulfate concentration and decrease of solution pH. Researchers also extended their previous research of ZnTe:Cu films by investigating films doped with low Cu concentrations (< 5 at. %). The low Cu concentration enabled them to increase the ZnTe:Cu post-annealing temperature without causing excessive Cu diffusion into CdTe or formation of secondary phases. The effects of Cu doping concentration and post-deposition annealing temperature on the structural, compositional, and electrical properties of ZnTe were studied systematically using X-ray diffraction, atomic force microscopy, electron microprobe, Hall effect, and conductivity measurements.

  5. Thin Metal Oxide Films to Modify a Window Layer in CdTe-Based Solar Cells for Improved Performance

    SciTech Connect (OSTI)

    Lemmon, John P.; Polikarpov, Evgueni; Bennett, Wendy D.; Kovarik, Libor

    2012-05-25

    We report on CdS/CdTe photovoltaic devices that contain a thin Ta₂O₅ film deposited onto the CdS window layer by sputtering. We show that for thicknesses below 5 nm, Ta₂O₅ films between CdS and CdTe positively affect the solar cell performance, improving JSC, VOC, and the cell power conversion efficiency despite the insulating nature of the interlayer material. Using the Ta₂O₅ interlayer, a VOC gain of over 100 mV was demonstrated compared to a CdTe/CdS baseline. Application of a 1nm Ta₂O₅ interlayer enabled the fabrication of CdTe solar cells with extremely thin (less than 30 nm) CdS window layers. The efficiency of these cells exceeded that of a base line cell with 95 nm of CdS.

  6. High electron mobility ZnO film for high-performance inverted polymer solar cells

    SciTech Connect (OSTI)

    Lv, Peiwen; Chen, Shan-Ci; Zheng, Qingdong; Huang, Feng Ding, Kai

    2015-04-20

    High-quality ZnO films (ZnO-MS) are prepared via magnetron sputtering deposition with a high mobility of about 2 cm{sup 2}/(V·s) and are used as electron transport layer for inverted polymer solar cells (PSCs) with polymer poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b′] dithiophene-co-3-fluorothieno[3,4-b]thiophene-2-carboxylate]:[6,6]-phenyl C71-butyric acid methyl ester as the active layer. A significant improvement of J{sub SC}, about 20% enhancement in contrast to the devices built on sol-gel derived ZnO film (ZnO-Sol), is found in the ZnO-MS based device. High performance ZnO-MS based PSCs exhibit power conversion efficiency (PCE) up to 8.55%, which is much better than the device based on ZnO-Sol (PCE = 7.78%). Further research on cathode materials is promising to achieve higher performance.

  7. Performance enhancement of thin film silicon solar cells based on distributed Bragg reflector and diffraction grating

    SciTech Connect (OSTI)

    Dubey, R. S.; Saravanan, S.; Kalainathan, S.

    2014-12-15

    The influence of various designing parameters were investigated and explored for high performance solar cells. Single layer grating based solar cell of 50 μm thickness gives maximum efficiency up to 24 % whereas same efficiency is achieved with the use of three bilayers grating based solar cell of 30 μm thickness. Remarkably, bilayer grating based solar cell design not only gives broadband absorption but also enhancement in efficiency with reduced cell thickness requirement. This absorption enhancement is attributed to the high reflection and diffraction from DBR and grating respectively. The obtained short-circuit current were 29.6, 32.9, 34.6 and 36.05 mA/cm{sup 2} of 5, 10, 20 and 30 μm cell thicknesses respectively. These presented designing efforts would be helpful to design and realize new generation of solar cells.

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

    SciTech Connect (OSTI)

    Gale, R.P.

    1994-01-01

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

  9. Thin-Film Photovoltaics on Solar House

    Broader source: Energy.gov [DOE]

    In this photograph, people are reflected on Team Germany's window louvers with integrated thin-film copper indium gallium selenide (CIGS) cells during the U.S. Department of Energy Solar Decathlon...

  10. Large-area Silicon-Film{trademark} panels and solar cells. Phase 2 technical report, January 1996--December 1996

    SciTech Connect (OSTI)

    Rand, J.A.; Barnett, A.M.; Checchi, J.C.; Culik, J.S.; Collins, S.R.; Ford, D.H.; Hall, R.B.; Jackson, E.L.; Kendall, C.L.

    1997-03-01

    The Silicon-Film{trademark} process is on an accelerated path to large-scale manufacturing. A key element in that development is optimizing the specific geometry of both the Silicon-Film{trademark} sheet and the resulting solar cell. That decision has been influenced by cost factors, engineering concerns, and marketing issues. The geometry investigation has focused first on sheet nominally 15 cm wide. This sheet generated solar cells with areas of 240 cm{sup 2} and 675 cm{sup 2}. Most recently, a new sheet fabrication machine was constructed that produces Silicon-Film{trademark} with a width in excess of 30 cm. Test results have indicated that there is no limit to the width of sheet generated by this process. The new wide material has led to prototype solar cells with areas of 300, 400, and 1,800 cm{sup 2}. Significant advances in solar-cell processing have been developed in support of fabricating large-area devices, including uniform emitter diffusion and anti-reflection coatings.

  11. Methods for forming thin-film heterojunction solar cells from I-III-VI.sub. 2

    DOE Patents [OSTI]

    Mickelsen, Reid A.; Chen, Wen S.

    1985-08-13

    An improved thin-film, large area solar cell, and methods for forming the same, having a relatively high light-to-electrical energy conversion efficiency and characterized in that the cell comprises a p-n type heterojunction formed of: (i) a first semiconductor layer comprising a photovoltaic active material selected from the class of I-III-VI.sub.2 chalcopyrite ternary materials which is vacuum deposited in a thin "composition-graded" layer ranging from on the order ot about 2.5 microns to about 5.0 microns (.congruent.2.5 .mu.m to .congruent.5.0 .mu.m) and wherein the lower region of the photovoltaic active material preferably comprises a low resistivity region of p-type semiconductor material having a superimposed region of relatively high resistivity, transient n-type semiconductor material defining a transient p-n homojunction; and (ii), a second semiconductor layer comprising a low resistivity n-type semiconductor material; wherein interdiffusion (a) between the elemental constituents of the two discrete juxtaposed regions of the first semiconductor layer defining a transient p-n homojunction layer, and (b) between the transient n-type material in the first semiconductor layer and the second n-type semiconductor layer, causes the The Government has rights in this invention pursuant to Contract No. EG-77-C-01-4042, Subcontract No. XJ-9-8021-1 awarded by the U.S. Department of Energy.

  12. Methods for forming thin-film heterojunction solar cells from I-III-VI.sub. 2

    DOE Patents [OSTI]

    Mickelsen, Reid A.; Chen, Wen S.

    1982-01-01

    An improved thin-film, large area solar cell, and methods for forming the same, having a relatively high light-to-electrical energy conversion efficiency and characterized in that the cell comprises a p-n type heterojunction formed of: (i) a first semiconductor layer comprising a photovoltaic active material selected from the class of I-III-VI.sub.2 chalcopyrite ternary materials which is vacuum deposited in a thin "composition-graded" layer ranging from on the order of about 2.5 microns to about 5.0 microns (.congruent.2.5.mu.m to .congruent.5.0.mu.m) and wherein the lower region of the photovoltaic active material preferably comprises a low resistivity region of p-type semiconductor material having a superimposed region of relatively high resistivity, transient n-type semiconductor material defining a transient p-n homojunction; and (ii), a second semiconductor layer comprising a low resistivity n-type semiconductor material; wherein interdiffusion (a) between the elemental constituents of the two discrete juxtaposed regions of the first semiconductor layer defining a transient p-n homojunction layer, and (b) between the transient n-type material in the first semiconductor layer and the second n-type semiconductor layer, causes the transient n-type material in The Government has rights in this invention pursuant to Contract No. EG-77-C-01-4042, Subcontract No. XJ-9-8021-1 awarded by the U.S. Department of Energy.

  13. Methods for forming thin-film heterojunction solar cells from I-III-VI{sub 2}

    DOE Patents [OSTI]

    Mickelsen, R.A.; Chen, W.S.

    1985-08-13

    An improved thin-film, large area solar cell, and methods for forming the same are disclosed, having a relatively high light-to-electrical energy conversion efficiency and characterized in that the cell comprises a p-n type heterojunction formed of: (i) a first semiconductor layer comprising a photovoltaic active material selected from the class of I-III-VI{sub 2} chalcopyrite ternary materials which is vacuum deposited in a thin ``composition-graded`` layer ranging from on the order of about 2.5 microns to about 5.0 microns ({approx_equal}2.5 {mu}m to {approx_equal}5.0 {mu}m) and wherein the lower region of the photovoltaic active material preferably comprises a low resistivity region of p-type semiconductor material having a superimposed region of relatively high resistivity, transient n-type semiconductor material defining a transient p-n homojunction; and (ii) a second semiconductor layer comprising a low resistivity n-type semiconductor material; wherein interdiffusion occurs (a) between the elemental constituents of the two discrete juxtaposed regions of the first semiconductor layer defining a transient p-n homojunction layer, and (b) between the transient n-type material in the first semiconductor layer and the second n-type semiconductor layer. 16 figs.

  14. Characterization of Epitaxial Film Silicon Solar Cells Grown on Seeded Display Glass: Preprint

    SciTech Connect (OSTI)

    Young, D. L.; Grover, S.; Teplin, C.; Stradins, P.; LaSalvia, V.; Chuang, T. K.; Couillard, J. G.; Branz, H. M.

    2012-06-01

    We report characterizations of epitaxial film crystal silicon (c-Si) solar cells with open-circuit voltages (Voc) above 560 mV. The 2-um absorber cells are grown by low-temperature (<750 degrees C) hot-wire CVD (HWCVD) on Corning EAGLE XG display glass coated with a layer-transferred (LT) Si seed. The high Voc is a result of low-defect epitaxial Si (epi-Si) growth and effective hydrogen passivation of defects. The quality of HWCVD epitaxial growth on seeded glass substrates depends on the crystallographic quality of the seed and the morphology of the epitaxial growth surface. Heterojunction devices consist of glass/c-Si LT seed/ epi n+ Si:P/epi n- Si:P/intrinsic a-Si:H/p+ a-Si:H/ITO. Similar devices grown on electronically 'dead' n+ wafers have given Voc {approx}630 mV and {approx}8% efficiency with no light trapping features. Here we study the effects of the seed surface polish on epi-Si quality, how hydrogenation influences the device character, and the dominant junction transport physics.

  15. Methods for forming thin-film heterojunction solar cells from I-III-VI[sub 2

    DOE Patents [OSTI]

    Mickelsen, R.A.; Chen, W.S.

    1982-06-15

    An improved thin-film, large area solar cell, and methods for forming the same are disclosed, having a relatively high light-to-electrical energy conversion efficiency and characterized in that the cell comprises a p-n type heterojunction formed of: (1) a first semiconductor layer comprising a photovoltaic active material selected from the class of I-III-VI[sub 2] chalcopyrite ternary materials which is vacuum deposited in a thin composition-graded'' layer ranging from on the order of about 2.5 microns to about 5.0 microns ([approx equal]2.5[mu]m to [approx equal]5.0[mu]m) and wherein the lower region of the photovoltaic active material preferably comprises a low resistivity region of p-type semiconductor material having a superimposed region of relatively high resistivity, transient n-type semiconductor material defining a transient p-n homojunction; and (2), a second semiconductor layer comprising a low resistivity n-type semiconductor material; wherein interdiffusion (a) between the elemental constituents of the two discrete juxtaposed regions of the first semiconductor layer defining a transient p-n homojunction layer, and (b) between the transient n-type material in the first semiconductor layer and the second n-type semiconductor layer, is allowed.

  16. Processing and modeling issues for thin-film solar cell devices: Annual subcontract report, January 16, 1995 -- January 15, 1996

    SciTech Connect (OSTI)

    Birkmire, R.W.; Phillips, J.E.; Buchanan, W.A.; Eser, E.; Hegedus, S.S.; McCandless, B.E.; Meyers, P.V.; Shafarman, W.N.

    1996-08-01

    The overall mission of the Institute of Energy Conversion is the development of thin film photovoltaic cells, modules, and related manufacturing technology and the education of students and professionals in photovoltaic technology. The objectives of this four-year NREL subcontract are to advance the state of the art and the acceptance of thin film PV modules in the areas of improved technology for thin film deposition, device fabrication, and material and device characterization and modeling, relating to solar cells based on CuInSe{sub 2} and its alloys, on a-Si and its alloys, and on CdTe. In the area of CuInSe{sub 2} and its alloys, EEC researchers have produced CuIn{sub 1-x}GaxSe{sub 2} films by selenization of elemental and alloyed films with H{sub 2}Se and Se vapor and by a wide variety of process variations employing co-evaporation of the elements. Careful design, execution and analysis of these experiments has led to an improved understanding of the reaction chemistry involved, including estimations of the reaction rate constants. Investigation of device fabrication has also included studies of the processing of the Mo, US and ZnO deposition parameters and their influence on device properties. An indication of the success of these procedures was the fabrication of a 15% efficiency CuIn{sub 1-x}GaxSe{sub 2} solar cell.

  17. Novel R2R Manufacturable Photonic-Enhanced Thin Film Solar Cells; January 28, 2010 -- January 31, 2011

    SciTech Connect (OSTI)

    Slafer, D.; Dalal, V.

    2012-03-01

    Final subcontract report for PV Incubator project 'Novel R2R Manufacturable Photonic-Enhanced Thin Film Solar Cells.' The goal of this program was to produce tandem Si cells using photonic bandgap enhancement technology developed at ISU and Lightwave Power that would have an NREL-verified efficiency of 7.5% on 0.25 cm{sup 2} area tandem junction cell on plastic substrates. This goal was met and exceeded within the timeframe and budget of the program. On smaller area cells, the efficiency was even higher, {approx}9.5% (not verified by NREL). Appropriate polymers were developed to fabricate photonic and plasmonic devices on stainless steel, Kapton and PEN substrates. A novel photonic-plasmon structure was developed which shows a promise of improving light absorption in thin film cells, a better light absorption than by any other scheme.

  18. Organic solvent vapor sensitive methylammonium lead trihalide film formation for efficient hybrid perovskite solar cells

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

    Lian, Jiarong; Wang, Qi; Yuan, Yongbo; Shao, Yuchuan; Huang, Jinsong

    2015-03-25

    In this study, the anisotropic electronic properties of the perovskite crystals originating from their non-cubic crystal structures can potentially give rise to the grain orientation correlated photovoltaic device performance. Here we report that an organic solvent vapor atmosphere introduced during the spin-coating and formation of perovskite films changes the orientation and size of perovskite grains. It was found that slightly larger but much more oriented methylammonium lead trihalide (CH3NH3PbI3) grains could be obtained under 1,2-dichlorobenzene (DCB) and dimethyl sulfoxide (DMSO) vapor atmospheres. The devices with more oriented grains outperformed regular devices with more random grains by a 50 mV largermore » open circuit voltage as well as a slightly increased fill factor. The device efficiency enhancement can be attributed to the longer charge recombination lifetime resulting from the reduced trap density and oriented grains. This result is important in providing guidelines for comparing the results from various groups because organic solvent vapors are generally present in a sealed glovebox for perovskite solar cell fabrication.« less

  19. Organic solvent vapor sensitive methylammonium lead trihalide film formation for efficient hybrid perovskite solar cells

    SciTech Connect (OSTI)

    Lian, Jiarong; Wang, Qi; Yuan, Yongbo; Shao, Yuchuan; Huang, Jinsong

    2015-03-25

    In this study, the anisotropic electronic properties of the perovskite crystals originating from their non-cubic crystal structures can potentially give rise to the grain orientation correlated photovoltaic device performance. Here we report that an organic solvent vapor atmosphere introduced during the spin-coating and formation of perovskite films changes the orientation and size of perovskite grains. It was found that slightly larger but much more oriented methylammonium lead trihalide (CH3NH3PbI3) grains could be obtained under 1,2-dichlorobenzene (DCB) and dimethyl sulfoxide (DMSO) vapor atmospheres. The devices with more oriented grains outperformed regular devices with more random grains by a 50 mV larger open circuit voltage as well as a slightly increased fill factor. The device efficiency enhancement can be attributed to the longer charge recombination lifetime resulting from the reduced trap density and oriented grains. This result is important in providing guidelines for comparing the results from various groups because organic solvent vapors are generally present in a sealed glovebox for perovskite solar cell fabrication.

  20. Barrier Coatings for Thin Film Solar Cells: Final Subcontract Report, September 1, 2002 -- January 30, 2008

    SciTech Connect (OSTI)

    Olsen, L. C.

    2010-03-01

    This program has involved investigations of the stability of CdTe and copper-indium-gallium-diselenide (CIGS) solar cells under damp heat conditions and effects of barrier coatings.

  1. Light trapping in thin film solar cells using textured photonic crystal

    DOE Patents [OSTI]

    Yi, Yasha; Kimerling, Lionel C.; Duan, Xiaoman; Zeng, Lirong

    2009-01-27

    A solar cell includes a photoactive region that receives light. A photonic crystal is coupled to the photoactive region, wherein the photonic crystal comprises a distributed Bragg reflector (DBR) for trapping the light.

  2. 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.

  3. Thin Film Solar Technologies | Open Energy Information

    Open Energy Info (EERE)

    help OpenEI by expanding it. Thin Film Solar Technologies is a company located in South Africa . References "Thin Film Solar Technologies" Retrieved from "http:...

  4. Electrical properties and surface morphology of electron beam evaporated p-type silicon thin films on polyethylene terephthalate for solar cells applications

    SciTech Connect (OSTI)

    Ang, P. C.; Ibrahim, K.; Pakhuruddin, M. Z.

    2015-04-24

    One way to realize low-cost thin film silicon (Si) solar cells fabrication is by depositing the films with high-deposition rate and manufacturing-compatible electron beam (e-beam) evaporation onto inexpensive foreign substrates such as glass or plastic. Most of the ongoing research is reported on e-beam evaporation of Si films on glass substrates to make polycrystalline solar cells but works combining both e-beam evaporation and plastic substrates are still scarce in the literature. This paper studies electrical properties and surface morphology of 1 µm electron beam evaporated Al-doped p-type silicon thin films on textured polyethylene terephthalate (PET) substrate for application as an absorber layer in solar cells. In this work, Si thin films with different doping concentrations (including an undoped reference) are prepared by e-beam evaporation. Energy dispersion X-ray (EDX) showed that the Si films are uniformly doped by Al dopant atoms. With increased Al/Si ratio, doping concentration increased while both resistivity and carrier mobility of the films showed opposite relationships. Root mean square (RMS) surface roughness increased. Overall, the Al-doped Si film with Al/Si ratio of 2% (doping concentration = 1.57×10{sup 16} atoms/cm{sup 3}) has been found to provide the optimum properties of a p-type absorber layer for fabrication of thin film Si solar cells on PET substrate.

  5. Hydrogenated TiO{sub 2} film for enhancing photovoltaic properties of solar cells and self-sensitized effect

    SciTech Connect (OSTI)

    He, Hongcai; Yang, Kui; Wang, Ning Luo, Feifei; Chen, Haijun

    2013-12-07

    Hydrogenated TiO{sub 2} film was obtained by annealing TiO{sub 2} film at 350 °C for 2 h with hydrogen, and TiO{sub 2} films were prepared by screen printing on fluorine-doped tin oxide glass. Structural characterization by X-ray diffraction and electron microscopy did not show obvious difference between hydrogenated TiO{sub 2} film and pristine TiO{sub 2} film. Through optical and electrochemical characterization, the hydrogenated TiO{sub 2} film showed enhanced absorption and narrowed band gap, as well as reduced TiO{sub 2} surface impedance and dark current. As a result, an obviously enhanced photovoltaic effect was observed in the solar cell with hydrogenated TiO{sub 2} as photoanode without adding any dye due to the self-sensitized effect of hydrogenated TiO{sub 2} film, which excited electrons injecting internal conduction band of TiO{sub 2} to generate more photocurrent.

  6. Large-area silicon-film{sup {trademark}} panels and solar cells. Phase I annual technical report, July 1, 1995--December 31, 1995

    SciTech Connect (OSTI)

    Rand, J.A.; Barnett, A.M.; Checchi, J.C.; Culik, J.S.

    1996-06-01

    AstroPower is establishing a low cost manufacturing process for Silicon-Film{trademark} solar cells and panels by taking advantage of the continuous nature of the Silicon-Film{trademark} technology. Under this effort, each step used in Silicon-Film{trademark} panel fabrication is being developed into a continuous/in-line manufacturing process. The following benefits are expected: an accelerated reduction of PV manufacturing cost for installed systems; a foundation for significantly increased production capacity; and a reduction in handling and waste streams. The process development will be based on a new 31-cm wide continuous Silicon-Film{trademark} sheet. Long-term goals include the development of a 24W, 30 cm x 60 cm Silicon-Film{trademark} solar cell and a manufacturing capability for a 384W, 4 inches x 8 inches Silicon-Film{trademark} panel for deployment in utility-scale applications.

  7. 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.

  8. Thin film solar cells by selenization sulfurization using diethyl selenium as a selenium precursor

    DOE Patents [OSTI]

    Dhere, Neelkanth G.; Kadam, Ankur A.

    2009-12-15

    A method of forming a CIGSS absorber layer includes the steps of providing a metal precursor, and selenizing the metal precursor using diethyl selenium to form a selenized metal precursor layer (CIGSS absorber layer). A high efficiency solar cell includes a CIGSS absorber layer formed by a process including selenizing a metal precursor using diethyl selenium to form the CIGSS absorber layer.

  9. 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%.

  10. Thin film cadmium telluride, zinc telluride, and mercury zinc telluride solar cells. Final subcontract report, 1 July 1988--31 December 1991

    SciTech Connect (OSTI)

    Chu, T.L.

    1992-04-01

    This report describes research to demonstrate (1) thin film cadmium telluride solar cells with a quantum efficiency of 75% or higher at 0. 44 {mu}m and a photovoltaic efficiency of 11.5% or greater, and (2) thin film zinc telluride and mercury zinc telluride solar cells with a transparency to sub-band-gap radiation of 65% and a photovoltaic conversion efficiency of 5% and 8%, respectively. Work was directed at (1) depositing transparent conducting semiconductor films by solution growth and metal-organic chemical vapor deposition (MOCVD) technique, (2) depositing CdTe films by close-spaced sublimation (CSS) and MOCVD techniques, (3) preparing and evaluating thin film CdTe solar cells, and (4) preparing and characterizing thin film ZnTe, CD{sub 1-x}Zn{sub 1-x}Te, and Hg{sub 1-x}Zn{sub x}Te solar cells. The deposition of CdS films from aqueous solutions was investigated in detail, and their crystallographic, optical, and electrical properties were characterized. CdTe films were deposited from DMCd and DIPTe at 400{degrees}C using TEGa and AsH{sub 3} as dopants. CdTe films deposited by CSS had significantly better microstructures than those deposited by MOCVD. Deep energy states in CdTe films deposited by CSS and MOCVD were investigated. Thin films of ZnTe, Cd{sub 1- x}Zn{sub x}Te, and Hg{sub 1-x}Zn{sub x}Te were deposited by MOCVD, and their crystallographic, optical, and electrical properties were characterized. 67 refs.

  11. Process for fabricating polycrystalline semiconductor thin-film solar cells, and cells produced thereby

    DOE Patents [OSTI]

    Wu, Xuanzhi; Sheldon, Peter

    2000-01-01

    A novel, simplified method for fabricating a thin-film semiconductor heterojunction photovoltaic device includes initial steps of depositing a layer of cadmium stannate and a layer of zinc stannate on a transparent substrate, both by radio frequency sputtering at ambient temperature, followed by the depositing of dissimilar layers of semiconductors such as cadmium sulfide and cadmium telluride, and heat treatment to convert the cadmium stannate to a substantially single-phase material of a spinel crystal structure. Preferably, the cadmium sulfide layer is also deposited by radio frequency sputtering at ambient temperature, and the cadmium telluride layer is deposited by close space sublimation at an elevated temperature effective to convert the amorphous cadmium stannate to the polycrystalline cadmium stannate with single-phase spinel structure.

  12. Polycrystalline thin film cadmium telluride solar cells fabricated by electrodeposition. Annual technical report, 20 March 1995--19 March 1996

    SciTech Connect (OSTI)

    Trefny, J.U.; Mao, D.

    1997-04-01

    The objective of this project is to develop improved processes for fabricating CdTe/CdS polycrystalline thin-film solar cells. Researchers used electrodeposition to form CdTe; electrodeposition is a non-vacuum, low-cost technique that is attractive for economic, large-scale production. During the past year, research and development efforts focused on several steps that are most critical to the fabricating high-efficiency CdTe solar cells. These include the optimization of the CdTe electrodeposition process, the effect of pretreatment of CdS substrates, the post-deposition annealing of CdTe, and back-contact formation using Cu-doped ZnTe. Systematic investigations of these processing steps have led to a better understanding and improved performance of the CdTe-based cells. Researchers studied the structural properties of chemical-bath-deposited CdS thin films and their growth mechanisms by investigating CdS samples prepared at different deposition times; investigated the effect of CdCl{sub 2} treatment of CdS films on the photovoltaic performance of CdTe solar cells; studied Cu-doped ZnTe as a promising material for forming stable, low-resistance contacts to the p-type CdTe; and investigated the effect of CdTe and CdS thickness on the photovoltaic performance of the resulting cells. As a result of their systematic investigation and optimization of the processing conditions, researchers improved the efficiency of CdTe/CdS cells using ZnTe back-contact and electrodeposited CdTe. The best CdTe/CdS cell exhibited a V{sub oc} of 0.778 V, a J{sub sc} of 22.4 mA/cm{sup 2}, a FF of 74%, and an efficiency of 12.9% (verified at NREL). In terms of individual parameters, researchers obtained a V{sub oc} over 0.8 V and a FF of 76% on other cells.

  13. Thin film solar energy collector

    SciTech Connect (OSTI)

    Farrauto, R.J.; Myers, H.; Williams, J.C.

    1982-03-23

    A solar energy collector has improved absorptance and emissivity levels comprising: (1) a silver-copper oxide-rhodium oxide solar absorption film, (2) a cerium oxide interlayer and a substrate of quartz, silica glass or metal. The cerium oxide interlayer minimizes agglomeration of the metal particles, maintains a relatively low thermal emittance and improves overall stability.

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

    SciTech Connect (OSTI)

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

    2014-03-07

    Thin-film solar cells based on silicon have emerged as an alternative to standard thick wafers technology, but they are less efficient, because of incomplete absorption of sunlight, and non-radiative recombinations. In this paper, we focus on the case of crystalline silicon (c-Si) devices, and we present a full analytic electro-optical model for p-n junction solar cells with Lambertian light trapping. This model is validated against numerical solutions of the drift-diffusion equations. We use this model to investigate the interplay between light trapping, and bulk and surface recombination. Special attention is paid to surface recombination processes, which become more important in thinner devices. These effects are further amplified due to the textures required for light trapping, which lead to increased surface area. We show that c-Si solar cells with thickness of a few microns can overcome 20% efficiency and outperform bulk ones when light trapping is implemented. The optimal device thickness in presence of light trapping, bulk and surface recombination, is quantified to be in the range of 1080??m, depending on the bulk quality. These results hold, provided the effective surface recombination is kept below a critical level of the order of 100?cm/s. We discuss the possibility of meeting this requirement, in the context of state-of-the-art techniques for light trapping and surface passivation. We show that our predictions are within the capability of present day silicon technologies.

  15. 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.

  16. Electrophoretic deposited TiO2 pigment-based back reflectors for thin film solar cells

    SciTech Connect (OSTI)

    Bills, Braden; Morris, Nathan; Dubey, Mukul; Wang, Qi; Fan, Qi Hua

    2015-01-16

    Highly reflective coatings with strong light scattering effect have many applications in optical components and optoelectronic devices. This paper reports titanium dioxide (TiO2) pigment-based reflectors that have 2.5 times higher broadband diffuse reflection than commercially produced aluminum or silver based reflectors and result in efficiency enhancements of a single-junction amorphous Si solar cell. Electrophoretic deposition is used to produce pigment-based back reflectors with high pigment density, controllable film thickness and site-specific deposition. Electrical conductivity of the pigment-based back reflectors is improved by creating electrical vias throughout the pigment-based back reflector by making holes using an electrical discharge / dielectric breakdown approach followed by a second electrophoretic deposition of conductive nanoparticles into the holes. While previous studies have demonstrated the use of pigment-based back reflectors, for example white paint, on glass superstrate configured thin film Si solar cells, this work presents a scheme for producing pigment-based reflectors on complex shape and flexible substrates. Finally, mechanical durability and scalability are demonstrated on a continuous electrophoretic deposition roll-to-roll system which has flexible metal substrate capability of 4 inch wide and 300 feet long.

  17. Optimal design of one-dimensional photonic crystal back reflectors for thin-film silicon solar cells

    SciTech Connect (OSTI)

    Chen, Peizhuan; Hou, Guofu Zhang, Jianjun Zhang, Xiaodan; Zhao, Ying

    2014-08-14

    For thin-film silicon solar cells (TFSC), a one-dimensional photonic crystal (1D PC) is a good back reflector (BR) because it increases the total internal reflection at the back surface. We used the plane-wave expansion method and the finite difference time domain (FDTD) algorithm to simulate and analyze the photonic bandgap (PBG), the reflection and the absorption properties of a 1D PC and to further explore the optimal 1D PC design for use in hydrogenated amorphous silicon (a-Si:H) solar cells. With identified refractive index contrast and period thickness, we found that the PBG and the reflection of a 1D PC are strongly influenced by the contrast in bilayer thickness. Additionally, light coupled to the top three periods of the 1D PC and was absorbed if one of the bilayers was absorptive. By decreasing the thickness contrast of the absorptive layer relative to the non-absorptive layer, an average reflectivity of 96.7% was achieved for a 1D PC alternatively stacked with a-Si:H and SiO{sub 2} in five periods. This reflectivity was superior to a distributed Bragg reflector (DBR) structure with 93.5% and an Ag film with 93.4%. n-i-p a-Si:H solar cells with an optimal 1D PC-based BR offer a higher short-circuit current density than those with a DBR-based BR or an AZO/Ag-based BR. These results provide new design rules for photonic structures in TFSC.

  18. Development of Thin Film Silicon Solar Cell Using Inkjet Printed Silicon and Other Inkjet Processes: Cooperative Research and Development Final Report, CRADA Number CRD-07-260

    SciTech Connect (OSTI)

    Sopori, B.

    2012-04-01

    The cost of silicon photovoltaics (Si-PV) can be greatly lowered by developing thin-film crystalline Si solar cells on glass or an equally lower cost substrate. Typically, Si film is deposited by thermal evaporation, plasma enhanced chemical vapor deposition, and sputtering. NREL and Silexos have worked under a CRADA to develop technology to make very low cost solar cells using liquid organic precursors. Typically, cyclopentasilane (CPS) is deposited on a glass substrate and then converted into an a-Si film by UV polymerization followed by low-temperature optical process that crystallizes the amorphous layer. This technique promises to be a very low cost approach for making a Si film.

  19. Adhesive for solar control film

    SciTech Connect (OSTI)

    Penn, H.J.

    1984-01-31

    A water-activatable adhesive useful for adhering a solar film, polyester (polyethylene terephthalate) film, to glass or to metal substrates. The adhesive comprises the reacted product of (A) gamma-isocyanatopropyltriethoxy silane, containing a free isocyanate (NCO) group, and (B) a thermoplastic polyester formed by reacting (i) a dibasic acid selected from the group consisting of terephthalic acid, isophthalic acid and hexahydrophthalic acid, and mixtures thereof, with (ii) a polymethylene glycol of the formula HO(CH/sub 2/) /SUB x/ OH where x is an integer from 2 to 10, neopentyl glycol and glycerin, and mixtures thereof, and (iii) an aliphatic dibasic acid selected from the group consisting of those having the formula HOOC(CH/sub 2/) /SUB n/ COOH where n is an integer from 1 to 8, and mixtures of such acids, whereby substantially no free NCO remains in the adhesive. Solar film is used for absorbing and/or reflecting solar radiation. Solar film can be a single sheet of polyester dyed sufficiently to absorb the glare of bright sunlight, or it can be a single sheet of polyester, on one side of which a reflective metal (most often aluminum) is deposited in an amount which can be totally reflective or in an amount which still allows visible light transmission and over which a protective coating is deposited, or it can be a laminated structure of the reflective film adhered to a clear or dyed polyester film by which means the reflective metal is sandwiched between two layers of polyester film, or it can be a laminated structure of a reflective film to a polyolefin film.

  20. Double-layer composite film based on hollow TiO{sub 2} boxes and P25 as photoanode for enhanced efficiency in dye-sensitized solar cells

    SciTech Connect (OSTI)

    Shi, Yue; Zhao, Li Wang, Shimin Li, Jing; Dong, Binghai; Xu, Zuxun; Wan, Li

    2014-11-15

    Highlights: • A novel TiO{sub 2} double-layer composite film is successfully fabricated. • The TiO{sub 2}-HB overlayer exhibited intense scattering ability. • The P25 particles underlayer can enlarge the contact area and increase the contact points between TiO{sub 2}-HB and FTO glass. • TiO{sub 2}-DLL film cells have the maximum conversion efficiency. - Abstract: A TiO{sub 2} double-layer composite film consisting of hollow TiO{sub 2} boxes (HB-TiO{sub 2}) as overlayer and commercial-grade TiO{sub 2} nanoparticles (P25) as underlayer is designed as the photoelectrode of dye-sensitized solar cells (DSSCs). The hollow TiO{sub 2} box has been employed as light-scattering part to increase the optical length in the film and enhance light-harvesting. It was found that the double-layer film cell with lower absorbed dye achieved the highest conversion efficiency and reach up to a maximum value of 6.4%, which is 226% higher than that of pure HB-TiO{sub 2} film cell (η = 1.96%) and 57.2% higher than that of pure P25 particles film cell under identical film thickness at a constant irradiation of 100 mW cm{sup −2}. The enhanced efficiency of double-layer film can be attributed to its light-scattering capability.

  1. Modification of opto-electronic properties of ZnO by incorporating metallic tin for buffer layer in thin film solar cells

    SciTech Connect (OSTI)

    Deepu, D. R.; Jubimol, J.; Kartha, C. Sudha; Louis, Godfrey; Vijayakumar, K. P.; Kumar, K. Rajeev

    2015-06-24

    In this report, the effect of incorporation of metallic tin (Sn) on opto-electronic properties of ZnO thin films is presented. ZnO thin films were deposited through ‘automated chemical spray pyrolysis’ (CSP) technique; later different quantities of ‘Sn’ were evaporated on it and subsequently annealed. Vacuum annealing showed a positive effect on crystallinity of films. Creation of sub band gap levels due to ‘Sn’ diffusion was evident from the absorption and PL spectra. The tin incorporated films showed good photo response in visible region. Tin incorporated ZnO thin films seem to satisfy the desirable criteria for buffer layer in thin film solar cells.

  2. High Volume Manufacturing of Silicon-Film Solar Cells and Modules; Final Subcontract Report, 26 February 2003 - 30 September 2003

    SciTech Connect (OSTI)

    Rand, J. A.; Culik, J. S.

    2005-10-01

    The objective of the PV Manufacturing R&D subcontract was to continue to improve AstroPower's technology for manufacturing Silicon-Film* wafers, solar cells, and modules to reduce costs, and increase production yield, throughput, and capacity. As part of the effort, new technology such as the continuous back metallization screen-printing system and the laser scribing system were developed and implemented. Existing processes, such as the silicon nitride antireflection coating system and the fire-through process were optimized. Improvements were made to the statistical process control (SPC) systems of the major manufacturing processes: feedstock preparation, wafer growth, surface etch, diffusion, and the antireflection coating process. These process improvements and improved process control have led to an increase of 5% relative power, and nearly 15% relative improvement in mechanical and visual yield.

  3. Thin film solar energy collector

    DOE Patents [OSTI]

    Aykan, Kamran; Farrauto, Robert J.; Jefferson, Clinton F.; Lanam, Richard D.

    1983-11-22

    A multi-layer solar energy collector of improved stability comprising: (1) a substrate of quartz, silicate glass, stainless steel or aluminum-containing ferritic alloy; (2) a solar absorptive layer comprising silver, copper oxide, rhodium/rhodium oxide and 0-15% by weight of platinum; (3) an interlayer comprising silver or silver/platinum; and (4) an optional external anti-reflective coating, plus a method for preparing a thermally stable multi-layered solar collector, in which the absorptive layer is undercoated with a thin film of silver or silver/platinum to obtain an improved conductor-dielectric tandem.

  4. Picosecond and nanosecond laser annealing and simulation of amorphous silicon thin films for solar cell applications

    SciTech Connect (OSTI)

    Theodorakos, I.; Zergioti, I.; Tsoukalas, D.; Raptis, Y. S.; Vamvakas, V.

    2014-01-28

    In this work, a picosecond diode pumped solid state laser and a nanosecond Nd:YAG laser have been used for the annealing and the partial nano-crystallization of an amorphous silicon layer. These experiments were conducted as an alternative/complementary to plasma-enhanced chemical vapor deposition method for fabrication of micromorph tandem solar cell. The laser experimental work was combined with simulations of the annealing process, in terms of temperature distribution evolution, in order to predetermine the optimum annealing conditions. The annealed material was studied, as a function of several annealing parameters (wavelength, pulse duration, fluence), as far as it concerns its structural properties, by X-ray diffraction, SEM, and micro-Raman techniques.

  5. (Sr,Ba)(Si,Ge){sub 2} for thin-film solar-cell applications: First-principles study

    SciTech Connect (OSTI)

    Kumar, Mukesh E-mail: mkgarg79@gmail.com; Umezawa, Naoto; Imai, Motoharu

    2014-05-28

    In order to meet the increasing demand for electric power generation from solar energy conversion, the development of efficient light absorber materials has been awaited. To this end, the electronic and optical properties of advanced alkaline-earth-metals disilicides and digermanides (SrSi{sub 2}, BaSi{sub 2}, SrGe{sub 2}, and BaGe{sub 2}) are studied by means of the density functional theory using HSE06 exchange-correlation energy functional. Our calculations show that all these orthorhombic structured compounds have fundamental indirect band gaps in the range E{sub g} ? 0.891.25 eV, which is suitable for solar cell applications. The estimated lattice parameters and band gaps are in good agreement with experiments. Our calculations show that the electronic band structures of all four compounds are very similar except in the vicinity of the ?-point. The valence band of these compounds is made up by Si(Ge)-p states, whereas the conduction band is composed of Sr(Ba)-d states. Their band alignments are carefully determined by estimating the work function of each compound using slab model. The optical properties are discussed in terms of the complex dielectric function ?(?)?=??{sub 1}(?)?+?i?{sub 2}(?). The static and high-frequency dielectric constants are calculated, taking into account the ionic contribution. The absorption coefficient ?(?) demonstrates that a low energy dispersion of the conduction band, which results in a flat conduction band minimum, leads to large optical activity in these compounds. Therefore, alkaline-earth-metals disilicides and digermanides possess great potential as light absorbers for applications in thin-film solar cell technologies.

  6. Photochemical Deposition of Semiconductor Thin Films and Their Application for Solar Cells and Gas Sensors

    SciTech Connect (OSTI)

    Ichimura, M.; Gunasekaran, M.; Sueyoshi, T.

    2009-06-01

    The photochemical deposition (PCD) technique was applied for solar cells and gas sensors. CdS and Cd{sub 1-x}Zn{sub x}S were deposited by PCD. Thiosulfate ions S{sub 2}O{sub 3}{sup 2-} act as a reductant and a sulfur source. The SnS absorption layer was deposited by three-step pulse electrochemical deposition. For the CdS/SnS structure, the best cell showed an efficiency of about 0.2%, while for the Cd{sub 1-x}Zn{sub x}S/SnS structure, an efficiency of up to 0.7% was obtained. For the gas sensor application, SnO{sub 2} was deposited by PCD from a solution containing SnSO{sub 4} and HNO{sub 3}. To enhance the sensitivity to hydrogen, Pd was doped by the photochemical doping method. The current increased by a factor of 10{sup 4} upon exposure to 5000 ppm hydrogen within 1 min at room temperature. 10{sup 3} times conductivity increase was observed even for 50 ppm hydrogen.

  7. A NOVEL LOW THERMAL BUDGET THIN-FILM POLYSILICON FABRICATION PROCESS FOR LARGE-AREA, HIGH-THROUGHPUT SOLAR CELL PRODUCTION

    SciTech Connect (OSTI)

    Yue Kuo

    2010-08-15

    A novel thin-film poly-Si fabrication process has been demonstrated. This low thermal budget process transforms the single- and multi-layer amorphous silicon thin films into a poly-Si structure in one simple step over a pulsed rapid thermal annealing process with the enhancement of an ultrathin Ni layer. The complete poly-Si solar cell was fabricated in a short period of time without deteriorating the underneath glass substrate. The unique vertical crystallization process including the mechanism is discussed. Influences of the dopant type and process parameters on crystal structure will be revealed. The poly-Si film structure has been proved using TEM, XRD, Raman, and XPS methods. The poly-Si solar cell structure and the performance have been examined. In principle, the new process is potentially applicable to produce large-area thin-film poly-Si solar cells at a high throughput and low cost. A critical issue in this process is to prevent the excessive dopant diffusion during crystallization. Process parameters and the cell structure have to be optimized to achieve the production goal.

  8. 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 ...

  9. 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

  10. Solar cells

    DOE Patents [OSTI]

    Peumans, Peter; Uchida, Soichi; Forrest, Stephen R.

    2013-06-18

    Organic photosensitive optoelectronic devices are disclosed. The devises are thin-film crystalline organic optoelectronic devices capable of generating a voltage when exposed to light, and prepared by a method including the steps of: depositing a first organic layer over a first electrode; depositing a second organic layer over the first organic layer; depositing a confining layer over the second organic layer to form a stack; annealing the stack; and finally depositing a second electrode over the second organic layer.

  11. Characterization of reactively sputtered molybdenum oxide films for solar cell application

    SciTech Connect (OSTI)

    Simchi, H.; Boyle, J. H.; Shafarman, W. N.; McCandless, B. E.; Meng, T.

    2013-07-07

    Molybdenum oxide (MoO{sub 3}) thin films were prepared via Radio Frequency (RF) sputtering at different ambient composition and post-deposition annealing. The effects on the structural, optical, and surface properties of the deposited films were investigated. The ambient oxygen concentration O{sub 2}/(O{sub 2} + Ar) was varied from 10% to 100% at 10 mTorr. Post deposition anneals were performed in Ar at 300-500 Degree-Sign C. The films were analyzed using glancing incidence x-ray diffraction (GIXRD), UV/Vis/NIR spectrophotometry, and x-ray photoelectron spectroscopy (XPS). As-deposited films have amorphous structures, independent of the oxygen partial pressure. Annealing at 300 Degree-Sign C in air resulted in crystallization of the molybdenum oxide films to the monoclinic {beta}-MoO{sub 3} phase. Samples annealed at 400 and 500 Degree-Sign C were identified as pure orthorhombic {alpha}-MoO{sub 3} phase with (020) preferred orientation. High resolution XPS studies showed the presence of Mo{sup 6+} (MoO{sub 3}) and Mo{sup 5+} (Mo{sub 4}O{sub 11}) oxidation states at the surface of as deposited and low temperature (300 Degree-Sign C) annealed films, and the Mo{sup 6+} to Mo{sup 5+} did not change much with deposition oxygen partial pressure. Annealing at 400-500 Degree-Sign C suppressed the oxygen deficiency at the surface, resulting in films with composition close to stoichiometric phases. UV/Vis/NIR spectrophotometry revealed that all films have a high optical transmittance (>80%) in the visible range, followed by a steep drop at {lambda} Almost-Equal-To 400 nm indicating a strong absorption due to band-to-band transition. Increasing the oxygen partial pressure had no significant effect on optical transmittance of the films, and the bandgaps in the range of 2.6 eV to 2.9 eV were obtained. Annealing at 300 Degree-Sign C had a negligible effect on the optical properties of the MoO{sub 3} films, but samples annealed at 400 Degree-Sign C and 500 Degree-Sign C exhibited

  12. 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.

  13. Facile method for synthesis of TiO{sub 2} film and its application in high efficiency dye sensitized-solar cell (DSSC)

    SciTech Connect (OSTI)

    Widiyandari, Hendri Gunawan, S. K.V.; Suseno, Jatmiko Endro; Purwanto, Agus; Diharjo, Kuncoro

    2014-02-24

    Dye-sensitized solar cells (DSSC) is a device which converts a solar energy to electrical energy. Different with semiconductor thin film based solar cell, DSSC utilize the sensitized-dye to absorb the photon and semiconductor such as titanium dioxide (TiO{sub 2}) and zinc oxide (ZnO) as a working electrode photoanode. In this report, the preparation of TiO{sub 2} film using a facile method of spray deposition and its application in DSSC have been presented. TiO{sub 2} photoanode was synthesized by growing the droplet of titanium tetraisopropoxide diluted in acid solution on the substrate of conductive glass flourine-doped tin oxide (FTO) with variation of precursor volume. DSSC was assemblied by sandwiching both of photoanode electrode and platinum counter electrode subsequently filling the area between these electrodes with triodine/iodine electrolite solution as redox pairs. The characterization of the as prepared DSSC using solar simulator (AM 1.5G, 100 mW/cm{sup 2}) and I-V source meter Keithley 2400 showed that the performance of DSSC was affected by the precursor volume.. The overall conversion efficiency of DSSC using the optimum TiO{sub 2} film was about 1.97% with the open circuit voltage (V{sub oc}) of 0.73 V, short circuit current density (J{sub sc}) of 4.61 mA and fill factor (FF) of 0.58.

  14. Effect of dopent on the structural and optical properties of ZnS thin film as a buffer layer in solar cell application

    SciTech Connect (OSTI)

    Vashistha, Indu B. Sharma, S. K.; Sharma, Mahesh C.; Sharma, Ramphal

    2015-08-28

    In order to find the suitable alternative of toxic CdS buffer layer, deposition of pure ZnS and doped with Al by chemical bath deposition method have been reported. Further as grown pure and doped thin films have been annealed at 150°C. The structural and surface morphological properties have been characterized by X-Ray diffraction (XRD) and Atomic Force Microscope (AFM).The XRD analysis shows that annealed thin film has been polycrystalline in nature with sphalerite cubic crystal structure and AFM images indicate increment in grain size as well as growth of crystals after annealing. Optical measurement data give band gap of 3.5 eV which is ideal band gap for buffer layer for solar cell suggesting that the obtained ZnS buffer layer is suitable in a low-cost solar cell.

  15. Investigation of blister formation in sputtered Cu{sub 2}ZnSnS{sub 4} absorbers for thin film solar cells

    SciTech Connect (OSTI)

    Bras, Patrice; Sterner, Jan; Platzer-Björkman, Charlotte

    2015-11-15

    Blister formation in Cu{sub 2}ZnSnS{sub 4} (CZTS) thin films sputtered from a quaternary compound target is investigated. While the thin film structure, composition, and substrate material are not correlated to the blister formation, a strong link between sputtering gas entrapment, in this case argon, and blistering effect is found. It is shown that argon is trapped in the film during sputtering and migrates to locally form blisters during the high temperature annealing. Blister formation in CZTS absorbers is detrimental for thin film solar cell fabrication causing partial peeling of the absorber layer and potential shunt paths in the complete device. Reduced sputtering gas entrapment, and blister formation, is seen for higher sputtering pressure, higher substrate temperature, and change of sputtering gas to larger atoms. This is all in accordance with previous publications on blister formation caused by sputtering gas entrapment in other materials.

  16. Damp-Heat Induced Degradation of Transparent Conducting Oxides for Thin Film Solar Cells (Presentation)

    SciTech Connect (OSTI)

    Pern, J.; Noufi, R.; Li, X.; DeHart, C.; To, B.

    2008-05-01

    The objectives are: (1) To achieve a high long-term performance reliability for the thin-film CIGS PV modules with more stable materials, device structure designs, and moisture-resistant encapsulation materials and schemes; (2) to evaluate the DH stability of various transparent conducting oxides (TCOs); (3) to identify the degradation mechanisms and quantify degradation rates; (4) to seek chemical and/or physical mitigation methods, and explore new materials. It's important to note that direct exposure to DH represents an extreme condition that a well-encapsulated thin film PV module may never experience.

  17. 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

  18. CdTe Thin Film Solar Cells and Modules Tutorial; NREL (National Renewable Energy Laboratory)

    SciTech Connect (OSTI)

    Albin, David S.

    2015-06-13

    This is a tutorial presented at the 42nd IEEE Photovoltaics Specialists Conference to cover the introduction, background, and updates on CdTe cell and module technology, including CdTe cell and module structure and fabrication.

  19. 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 ...

  20. 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). ...

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

    SciTech Connect (OSTI)

    Noufi, R.; Zweibel, K.

    2006-05-01

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

  2. Overview and Challenges of Thin Film Solar Electric Technologies

    SciTech Connect (OSTI)

    Ullal, H. S.

    2008-12-01

    In this paper, we report on the significant progress made worldwide by thin-film solar cells, namely, amorphous silicon (a-Si), cadmium telluride (CdTe), and copper indium gallium diselenide (CIGS). Thin-film photovoltaic (PV) technology status is also discussed in detail. In addition, R&D and technology challenges in all three areas are elucidated. The worldwide estimated projection for thin-film PV technology production capacity announcements are estimated at more than 5000 MW by 2010.

  3. Dye sensitized solar cell applications of CdTiO{sub 3}–TiO{sub 2} composite thin films deposited from single molecular complex

    SciTech Connect (OSTI)

    Ehsan, Muhammad Ali; Khaledi, Hamid; Pandikumar, Alagarsamy; Huang, Nay Ming; Arifin, Zainudin; Mazhar, Muhammad

    2015-10-15

    A heterobimetallic complex [Cd{sub 2}Ti{sub 4}(μ-O){sub 6}(TFA){sub 8}(THF){sub 6}]·1.5THF (1) (TFA=trifluoroacetato, THF=tetrahydrofuran) comprising of Cd:Ti (1:2) ratio was synthesized by a chemical reaction of cadmium (II) acetate with titanium (IV) isopropoxide and triflouroacetic acid in THF. The stoichiometry of (1) was recognized by single crystal X-ray diffraction, spectroscopic and elemental analyses. Thermal studies revealed that (1) neatly decomposes at 450 °C to furnish 1:1 ratio of cadmium titanate:titania composite oxides material. The thin films of CdTiO{sub 3}–TiO{sub 2} composite oxides were deposited at 550 °C on fluorine doped tin oxide coated conducting glass substrate in air ambient. The micro-structure, crystallinity, phase identification and chemical composition of microspherical architectured CdTiO{sub 3}–TiO{sub 2} composite thin film have been determined by scanning electron microscopy, X-ray diffraction, Raman spectroscopy and energy dispersive X-ray analysis. The scope of composite thin film having band gap of 3.1 eV was explored as photoanode for dye-sensitized solar cell application. - Graphical abstarct: Microspherical designed CdTiO{sub 3}–TiO{sub 2} composite oxides photoanode film has been fabricated from single source precursor [Cd{sub 2}Ti{sub 4}(μ-O){sub 6}(TFA){sub 8}(THF){sub 6}]·1.5THF via aerosol assisted chemical vapor deposition technique for dye sensitized solar cell application. - Highlights: • Synthesis and characterization of a heterobimetallic Cd–Ti complex. • Fabrication of CdTiO{sub 3}–TiO{sub 2} thin film photoelectrode. • Application as dye sensitized photoanode for solar application.

  4. 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.

  5. Enhancement of current collection in epitaxial lift-off InAs/GaAs quantum dot thin film solar cell and concentrated photovoltaic study

    SciTech Connect (OSTI)

    Sogabe, Tomah Shoji, Yasushi; Tamayo, Efrain; Okada, Yoshitaka; Mulder, Peter; Schermer, John

    2014-09-15

    We report the fabrication of a thin film InAs/GaAs quantum dot solar cell (QD cell) by applying epitaxial lift-off (ELO) approach to the GaAs substrate. We confirmed significant current collection enhancement (?0.91?mA/cm{sup 2}) in the ELO-InAs QD cell within the wavelength range of 700?nm900?nm when compared to the ELO-GaAs control cell. This is almost six times of the sub-GaAs bandgap current collection (?0.16?mA/cm{sup 2}) from the wavelength range of 900?nm and beyond, we also confirmed the ELO induced resonance cavity effect was able to increase the solar cell efficiency by increasing both the short circuit current and open voltage. The electric field intensity of the resonance cavity formed in the ELO film between the Au back reflector and the GaAs front contact layer was analyzed in detail by finite-differential time-domain (FDTD) simulation. We found that the calculated current collection enhancement within the wavelength range of 700?nm900?nm was strongly influenced by the size and shape of InAs QD. In addition, we performed concentrated light photovoltaic study and analyzed the effect of intermediate states on the open voltage under varied concentrated light intensity for the ELO-InAs QD cell.

  6. 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, ...

  7. 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.

  8. 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.

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

    DOE Patents [OSTI]

    Bhattacharya, Raghu N.; Hasoon, Falah S.; Wiesner, Holm; Keane, James; Noufi, Rommel; Ramanathan, Kannan

    1999-02-16

    A photovoltaic cell exhibiting an overall conversion efficiency of 13.6% is prepared from a copper-indium-gallium-diselenide precursor thin film. The film is fabricated by first simultaneously electrodepositing copper, indium, gallium, and selenium onto a glass/molybdenum substrate (12/14). The electrodeposition voltage is a high frequency AC voltage superimposed upon a DC voltage to improve the morphology and growth rate of the film. The electrodeposition is followed by physical vapor deposition to adjust the final stoichiometry of the thin film to approximately Cu(In.sub.1-n Ga.sub.x)Se.sub.2, with the ratio of Ga/(In+Ga) being approximately 0.39.

  10. 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.

  11. Manipulating hybrid structures of polymer/a-Si for thin film solar cells

    SciTech Connect (OSTI)

    Peng, Ying; He, Zhiqun, E-mail: zhqhe@bjtu.edu.cn, E-mail: J.I.B.Wilson@hw.ac.uk; Zhang, Zhi; Liang, Chunjun [Key Laboratory of Luminescence and Optical Information, Ministry of Education, Institute of Optoelectronic Technology, Beijing Jiaotong University, Beijing 100044 (China); Diyaf, Adel; Ivaturi, Aruna; Wilson, John I. B., E-mail: zhqhe@bjtu.edu.cn, E-mail: J.I.B.Wilson@hw.ac.uk [SUPA, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom)

    2014-03-10

    A series of uniform polymer/amorphous silicon hybrid structures have been fabricated by means of solution-casting for polymer and radio frequency excited plasma enhanced chemical vapour deposition for amorphous silicon (a-Si:H). Poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) functioned as a photoactive donor, while the silicon layer acted as an acceptor. It is found that matching the hole mobility of the polymer to the electron mobility of amorphous silicon is critical to improve the photovoltaic performance from hybrid cells. A three-layer p-i-n structure of ITO/PEDOT:PSS(200?nm)/i-Si(450?nm)/n-Si(200?nm)/Al with a power conversion efficiency of 4.78% under a standard test condition was achieved.

  12. 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...

  13. 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.

  14. 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.

  15. 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.

  16. Theoretical Analysis of Effects of Deep Level, Back Contact, and Absorber Thickness on Capacitance-Voltage Profiling of CdTe Thin-Film Solar Cells

    SciTech Connect (OSTI)

    Li, J. V.; Halverson, A. F.; Sulima, O. V.; Bansal, S.; Burst, J. M.; Barnes, T. M.; Gessert, T. A.; Levi, D. H.

    2012-05-01

    The apparent carrier density profile measured by the capacitance-voltage technique in CdTe thin-film solar cells frequently displays a distinctive U-shape. We show that, even assuming a uniform carrier density, such a U-shape may arise from deep levels, a non-ohmic back-contact, and a thin absorber, which are commonly present in practical CdTe thin-film solar cells. A thin CdTe absorber contributes to the right branch of the U-shape due to a punch-through effect at reverse or zero biases, when the CdTe absorber is nearly fully depleted. A rectifying back-contact contributes to both branches of the U-shape due to voltage sharing with the front junction under a forward bias and early punch-through under a reverse bias. Deep levels contribute to the right branch, but also raise the bottom of the U-shape, leading to an overestimate of carrier density.

  17. Thin film photovoltaic cells

    DOE Patents [OSTI]

    Rothwarf, Allen

    1981-01-01

    A solar cell has as its transparent electrical contact a grid made from a non-noble metal by providing a layer of copper oxide between the transparent electrical contact and the absorber-generator.

  18. 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...

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Polycrystalline thin-film cadmium telluride solar cells fabricated by electrodeposition. Annual subcontract report, 20 March 1992--19 March 1993

    SciTech Connect (OSTI)

    Trefny, J.U.; Furtak, T.E.; Wada, N.; Williamson, D.L.; Kim, D.

    1993-08-01

    This report describes progress during the first year of a 3-year program at Colorado School of Mines, based upon earlier studies performed by Ametek Corporation, to develop specific layers of the Ametek n-i-p structure as well as additional studies of several transparent conducting oxides. Thin films of ZnO and ZnO:Al were deposited under various conditions. For the n-layer of the Ametek structure, a dip-coating method was developed for the deposition of CdS films. The authors also present data on the characterization of these films by X-ray diffraction, Raman spectroscopy, scanning tunneling microscopy, small-angle X-ray scattering, and other techniques. They made progress in the electrodeposition of the CdTe i-layer of the Ametek structure. They developed appropriate electrochemical baths and are beginning to understand the role of the many experimental parameters that must be controlled to obtain high-quality films of this material. They explored the possibility of using an electrochemical process for fabricating the ZnTe p-layer. Some preliminary success was achieved, and this step will be pursued in the next phase. Finally, they fabricated a number of ``dot`` solar cells with the structure glass/SnO{sub 2}/CdS/CdTe/Au. Several cells with efficiencies in the range of 5%-6% were obtained, and they are confident, given recent progress, that cells with efficiencies in excess of 10% will be achieved in the near future.

  4. 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,...

  5. Solar Thin Films Inc formerly American United Global Inc | Open...

    Open Energy Info (EERE)

    Films Inc formerly American United Global Inc Jump to: navigation, search Name: Solar Thin Films Inc (formerly American United Global Inc) Place: New York, New York Zip: 10038...

  6. Fabrication and characterization of Al{sub 2}O{sub 3} /Si composite nanodome structures for high efficiency crystalline Si thin film solar cells

    SciTech Connect (OSTI)

    Zhang, Ruiying; Zhu, Jian; Zhang, Zhen; Wang, Yanyan; Qiu, Bocang; Liu, Xuehua; Zhang, Jinping; Zhang, Yi; Fang, Qi; Ren, Zhong; Bai, Yu

    2015-12-15

    We report on our fabrication and characterization of Al{sub 2}O{sub 3}/Si composite nanodome (CND) structures, which is composed of Si nanodome structures with a conformal cladding Al{sub 2}O{sub 3} layer to evaluate its optical and electrical performance when it is applied to thin film solar cells. It has been observed that by application of Al{sub 2}O{sub 3}thin film coating using atomic layer deposition (ALD) to the Si nanodome structures, both optical and electrical performances are greatly improved. The reflectivity of less than 3% over the wavelength range of from 200 nm to 2000 nm at an incident angle from 0° to 45° is achieved when the Al{sub 2}O{sub 3} film is 90 nm thick. The ultimate efficiency of around 27% is obtained on the CND textured 2 μm-thick Si solar cells, which is compared to the efficiency of around 25.75% and 15% for the 2 μm-thick Si nanodome surface-decorated and planar samples respectively. Electrical characterization was made by using CND-decorated MOS devices to measure device’s leakage current and capacitance dispersion. It is found the electrical performance is sensitive to the thickness of the Al{sub 2}O{sub 3} film, and the performance is remarkably improved when the dielectric layer thickness is 90 nm thick. The leakage current, which is less than 4x10{sup −9} A/cm{sup 2} over voltage range of from -3 V to 3 V, is reduced by several orders of magnitude. C-V measurements also shows as small as 0.3% of variation in the capacitance over the frequency range from 10 kHz to 500 kHz, which is a strong indication of surface states being fully passivated. TEM examination of CND-decorated samples also reveals the occurrence of SiO{sub x} layer formed between the interface of Si and the Al{sub 2}O{sub 3} film, which is thin enough that ensures the presence of field-effect passivation, From our theoretical and experimental study, we believe Al{sub 2}O{sub 3} coated CND structures is a truly viable approach to achieving higher device

  7. 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.

  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. Modeling of capacitance transients of thin-film solar cells: A valuable tool to gain information on perturbing layers or interfaces

    SciTech Connect (OSTI)

    Lauwaert, Johan Van Puyvelde, Lisanne; Vrielinck, Henk; Lauwaert, Jeroen; Thybaut, Joris W.

    2014-02-03

    Thin-film electronic and photovoltaic devices often comprise, in addition to the anticipated p-n junctions, additional non-ideal ohmic contacts between layers. This may give rise to additional signals in capacitance spectroscopy techniques that are not directly related to defects in the structure. In this paper, we present a fitting algorithm for transient signals arising from such an additional junction. The fitting results are in excellent agreement with the diode characteristics extracted from static measurements on individual components. Finally, the algorithm is applied for determining the barriers associated with anomalous signals reported for selected CuIn{sub 1x}Ga{sub x}Se{sub 2} and CdTe solar cells.

  10. Effect of heat treatments and window layer processing on the characteristics of CuInGaSe{sub 2} thin film solar cells

    SciTech Connect (OSTI)

    Ramanathan, K.; Contreras, M.A.; Tuttle, J.R.

    1996-05-01

    Interaction between chemical bath deposited CdS and ZnO window layers are a focus of this paper. Low temperature anneals were used to follow the changes at the interface. Optical absorption spectra show that CdS and ZnO intermix upon annealing. When applied to ZnO/CdS/CuInGaSe{sub 2} thin film solar cells, changes in the short and long wavelength response were observed. The latter is attributed to an increase in the energy gap of the absorber by diffusion of S. The interdiffusion is shown to increase the short wavelength collection, and hence the current density of the devices. Photoluminescence data provides some indication of the quality of the interface.

  11. Cadmium-free junction fabrication process for CuInSe.sub.2 thin film solar cells

    DOE Patents [OSTI]

    Ramanathan, Kannan V.; Contreras, Miguel A.; Bhattacharya, Raghu N.; Keane, James; Noufi, Rommel

    1999-01-01

    The present invention provides an economical, simple, dry and controllable semiconductor layer junction forming process to make cadmium free high efficiency photovoltaic cells having a first layer comprised primarily of copper indium diselenide having a thin doped copper indium diselenide n-type region, generated by thermal diffusion with a group II(b) element such as zinc, and a halide, such as chlorine, and a second layer comprised of a conventional zinc oxide bilayer. A photovoltaic device according the present invention includes a first thin film layer of semiconductor material formed primarily from copper indium diselenide. Doping of the copper indium diselenide with zinc chloride is accomplished using either a zinc chloride solution or a solid zinc chloride material. Thermal diffusion of zinc chloride into the copper indium diselenide upper region creates the thin n-type copper indium diselenide surface. A second thin film layer of semiconductor material comprising zinc oxide is then applied in two layers. The first layer comprises a thin layer of high resistivity zinc oxide. The second relatively thick layer of zinc oxide is doped to exhibit low resistivity.

  12. High-Rate Fabrication of a-Si-Based Thin-Film Solar Cells Using Large-Area VHF PECVD Processes

    SciTech Connect (OSTI)

    Deng, Xunming; Fan, Qi Hua

    2011-12-31

    The University of Toledo (UT), working in concert with it’s a-Si-based PV industry partner Xunlight Corporation (Xunlight), has conducted a comprehensive study to develop a large-area (3ft x 3ft) VHF PECVD system for high rate uniform fabrication of silicon absorber layers, and the large-area VHF PECVD processes to achieve high performance a-Si/a-SiGe or a-Si/nc-Si tandem junction solar cells during the period of July 1, 2008 to Dec. 31, 2011, under DOE Award No. DE-FG36-08GO18073. The project had two primary goals: (i) to develop and improve a large area (3 ft × 3 ft) VHF PECVD system for high rate fabrication of > = 8 Å/s a-Si and >= 20 Å/s nc-Si or 4 Å/s a-SiGe absorber layers with high uniformity in film thicknesses and in material structures. (ii) to develop and optimize the large-area VHF PECVD processes to achieve high-performance a-Si/nc-Si or a-Si/a-SiGe tandem-junction solar cells with >= 10% stable efficiency. Our work has met the goals and is summarized in “Accomplishments versus goals and objectives”.

  13. 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...

  14. 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 ...

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

    SciTech Connect (OSTI)

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

    2014-12-21

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

  16. 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.

  17. Thin film photovoltaic cell

    DOE Patents [OSTI]

    Meakin, John D.; Bragagnolo, Julio

    1982-01-01

    A thin film photovoltaic cell having a transparent electrical contact and an opaque electrical contact with a pair of semiconductors therebetween includes utilizing one of the electrical contacts as a substrate and wherein the inner surface thereof is modified by microroughening while being macro-planar.

  18. 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.

  19. SnO{sub 2} films: In-situ template-sacrificial growth and photovoltaic property based on SnO{sub 2}/poly(3-hexyl-thiophene) for hybrid solar cell

    SciTech Connect (OSTI)

    Zhang, Yange; Li, Pinjiang; Xu, Xiaoyun; Wang, Min; Shen, Jinfeng; Zhang, Fujuan; Zheng, Zhi

    2015-10-15

    Highlights: • SnO{sub 2} nanocrystals/thin films were fabricated on ITO glass substrate from preformed SnS thin film as sacrificial template. • The SnO{sub 2} film and SnO{sub 2}/P3HT was characterized by several techniques. • The new hybrid solar cell device was based on the hybrid thin film of SnO{sub 2} NCs and P3HT composites. - Abstract: we described a facile in-situ wet chemical method to prepare SnO{sub 2} thin film on ITO glass substrate from preformed SnS thin film as sacrificial template. The chemical conversion process of SnS to SnO{sub 2} was studied. The SnO{sub 2} film and SnO{sub 2}/P3HT was characterized by several techniques, such as powder X-ray diffract meter (XRD), Raman spectrometer, scanning electron microscope (SEM), atomic force microscope (AFM) and UV–vis spectrophotometer in detail. The new SnO{sub 2}/P3HT hybrid solar cell device showed an open-circuit voltage of 0.185 V, a short-circuit current density of 0.366 mA/cm{sup 2} and a fill factor of 0.247, corresponding to a power conversion efficiency of 0.0167%.

  20. 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.

  1. 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).

  2. Thin film absorber for a solar collector

    DOE Patents [OSTI]

    Wilhelm, William G.

    1985-01-01

    This invention pertains to energy absorbers for solar collectors, and more particularly to high performance thin film absorbers. The solar collectors comprising the absorber of this invention overcome several problems seen in current systems, such as excessive hardware, high cost and unreliability. In the preferred form, the apparatus features a substantially rigid planar frame with a thin film window bonded to one planar side of the frame. An absorber in accordance with the present invention is comprised of two thin film layers that are sealed perimetrically. In a preferred embodiment, thin film layers are formed from a metal/plastic laminate. The layers define a fluid-tight planar envelope of large surface area to volume through which a heat transfer fluid flows. The absorber is bonded to the other planar side of the frame. The thin film construction of the absorber assures substantially full envelope wetting and thus good efficiency. The window and absorber films stress the frame adding to the overall strength of the collector.

  3. 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.

  4. 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.

  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 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

  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. 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.

  8. 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...

  9. Apparatus for forming thin-film heterojunction solar cells employing materials selected from the class of I-III-VI.sub.2 chalcopyrite compounds

    DOE Patents [OSTI]

    Mickelsen, Reid A.; Chen, Wen S.

    1983-01-01

    Apparatus for forming thin-film, large area solar cells having a relatively high light-to-electrical energy conversion efficiency and characterized in that the cell comprises a p-n-type heterojunction formed of: (i) a first semiconductor layer comprising a photovoltaic active material selected from the class of I-III-VI.sub.2 chalcopyrite ternary materials which is vacuum deposited in a thin "composition-graded" layer ranging from on the order of about 2.5 microns to about 5.0 microns (.congruent.2.5 .mu.m to .congruent.5.0 .mu.m) and wherein the lower region of the photovoltaic active material preferably comprises a low resistivity region of p-type semiconductor material having a superimposed region of relatively high resistivity, transient n-type semiconductor material defining a transient p-n homojunction; and (ii), a second semiconductor layer comprising a low resistivity n-type semiconductor material wherein interdiffusion (a) between the elemental constituents of the two discrete juxtaposed regions of the first semiconductor layer defining a transient p-n homojunction layer, and (b) between the transient n-type material in the first semiconductor layer and the second n-type semiconductor layer, causes the transient n-type material in the first semiconductor layer to evolve into p-type material, thereby defining a thin layer heterojunction device characterized by the absence of voids, vacancies and nodules which tend to reduce the energy conversion efficiency of the system.

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

    DOE Patents [OSTI]

    Bhattacharya, Raghu N.; Contreras, Miguel A.; Keane, James; Tennant, Andrew L.; Tuttle, John R.; Ramanathan, Kannan; Noufi, Rommel

    1998-03-24

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

  11. NREL and Stanford Team up on Peel-and-Stick Solar Cells - News...

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

    A scientific paper, "Peel and Stick: Fabricating Thin Film Solar Cells on Universal Substrates," appears in the online version of Scientific Reports, a subsidiary of the British ...

  12. Double Power Output for GaAs Solar Cells Embedded in Luminescent...

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

    Double power output of bifacial thin-film GaAs microscale solar cells is achieved by embedding in luminescent waveguides (LSCs) with light- trapping backside reflectors (BSRs). ...

  13. PowerFilm Solar Inc | Open Energy Information

    Open Energy Info (EERE)

    Solar Inc Place: Boone, Iowa Zip: 50036 7538 Product: Developer of a method for manufacturing thin-film amorphous silicon modules, from silane gas and plastic substrate, using...

  14. Overview and Challenges of Thin Film Solar Electric Technologies

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

    and Challenges of Thin Film Solar Electric Technologies H.S. Ullal Presented at the World Renewable Energy Congress X and Exhibition 2008 Glasgow, Scotland, United Kingdom July ...

  15. Tax Credits Give Thin-Film Solar a Big Boost

    Broader source: Energy.gov [DOE]

    California company will expand its capacity to make its thin-film solar panels by more than ten times, thanks to two Recovery Act tax credits.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Method of fabricating high-efficiency Cu(In,Ga)(Se,S){sub 2} thin films for solar cells

    DOE Patents [OSTI]

    Noufi, R.; Gabor, A.M.; Tuttle, J.R.; Tennant, A.L.; Contreras, M.A.; Albin, D.S.; Carapella, J.J.

    1995-08-15

    A process for producing a slightly Cu-poor thin film of Cu(In,Ga)(Se,S){sub 2} comprises depositing a first layer of (In,Ga){sub x} (Se,S){sub y} followed by depositing just enough Cu+(Se,S) or Cu{sub x} (Se,S) to produce the desired slightly Cu-poor material. In a variation, most, but not all, (about 90 to 99%) of the (In,Ga){sub x} (Se,S){sub y} is deposited first, followed by deposition of all the Cu+(Se,S) or Cu{sub x} (Se,S) to go near stoichiometric, possibly or even preferably slightly Cu-rich, and then in turn followed by deposition of the remainder (about 1 to 10%) of the (In,Ga){sub x} (Se,S){sub y} to end with a slightly Cu-poor composition. In yet another variation, a small portion (about 1 to 10%) of the (In,Ga){sub x} (Se,S){sub y} is first deposited as a seed layer, followed by deposition of all of the Cu+(Se,S) or Cu{sub x} (Se,S) to make a very Cu-rich mixture, and then followed deposition of the remainder of the (In,Ga){sub x} (Se,S){sub y} to go slightly Cu-poor in the final Cu(In,Ga)(Se,S){sub 2} thin film. 5 figs.

  1. Method of fabricating high-efficiency Cu(In,Ga)(SeS).sub.2 thin films for solar cells

    DOE Patents [OSTI]

    Noufi, Rommel; Gabor, Andrew M.; Tuttle, John R.; Tennant, Andrew L.; Contreras, Miguel A.; Albin, David S.; Carapella, Jeffrey J.

    1995-01-01

    A process for producing a slightly Cu-poor thin film of Cu(In,Ga)(Se,S).sub.2 comprises depositing a first layer of (In,Ga).sub.x (Se,S).sub.y followed by depositing just enough Cu+(Se,S) or Cu.sub.x (Se,S) to produce the desired slightly Cu-poor material. In a variation, most, but not all, (about 90 to 99%) of the (In,Ga).sub.x (Se,S).sub.y is deposited first, followed by deposition of all the Cu+(Se,S) or Cu.sub.x (Se,S) to go near stoichiometric, possibly or even preferably slightly Cu-rich, and then in turn followed by deposition of the remainder (about 1 to 10%) of the (In,Ga).sub.x (Se,S).sub.y to end with a slightly Cu-poor composition. In yet another variation, a small portion (about 1 to 10%) of the (In,Ga).sub.x (Se,S).sub.y is first deposited as a seed layer, followed by deposition of all of the Cu+(Se,S) or Cu.sub.x (Se,S) to make a very Cu-rich mixture, and then followed deposition of the remainder of the (In,Ga).sub.x (Se,S).sub.y to go slightly Cu-poor in the final Cu(In,Ga)(Se,S).sub.2 thin film.

  2. 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.

  3. Solar films seen as cheaper alternative to reflective glass

    SciTech Connect (OSTI)

    Andrews, W.

    1982-06-28

    It costs only one-third as much to install solar film used with clear glass as it does to install reflective glass, and further savings will come in maintenance and replacement costs. Except for the Sunbelt, architects and builders are less enthusiastic about the solar films and reluctant to use them in quality construction because of their reputation for deteriorating. Manufacturers note that field-applied films are not as durable as factory-bonded reflective glass. Several users and architects report their experiences with solar-film performance. Two directories list 116 major manufacturers of doors and windows and 33 suppliers of window-treatment products. (DCK)

  4. Optical films for solar energy applications

    SciTech Connect (OSTI)

    Lampert, C.M.

    1983-05-01

    A number of solar energy conversion materials and coatings are considered stratified media. They are generally classified as graded-index media or layered media. With index coatings, two components (such as air and SiO/sub 2/ or Cr and Cr/sub 2/O/sub 3/) are created in a non-linear fashion with depth into the coating. By simple materials admixing, a coating is formed with varying optical constants (n, k). Layered media generally consist of interference films, films with thicknesses below the wavelength of light, made of alternating dissimilar media such as a dielectric and metal combination. This paper presents details of the properties of stratified coatings. Coatings that serve as antireflection films, transparent optical insulation (silica aerogel), thermal heat mirrors, or selective absorbers are also discussed. Both interference and semiconductor types of heat mirrors are evaluated. Four types of selective absorbers are also covered: dendritic optical trapping, graded composite, metal/dielectric tandems, and optical interference techniques.

  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...

  6. 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....

  7. 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 ...

  8. 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.

  9. 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%.

  10. Stabilization of solar films against hi temperature deactivation

    DOE Patents [OSTI]

    Jefferson, Clinton F.

    1984-03-20

    A multi-layer solar energy collector of improved stability comprising: (1) a solar absorptive film consisting essentially of copper oxide, cobalt oxide and manganese oxide; (2) a substrate of quartz, silicate glass or a stainless steel; and (3) an interlayer of platinum, plus a method for preparing a thermally stable multi-layered solar collector, in which the absorptive layer is undercoated with a thin film of platinum to obtain a stable conductor-dielectric tandem.

  11. 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

  12. Tunable Nanocrystalline CZTS for Solar Photovoltaics with No...

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

    PDF Document Publication Nanocrystal Summary (230 KB) Example solar cell Example solar cell Technology Marketing Summary Thin-film solar cells are expected to replace the current ...

  13. 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.

  14. 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...

  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. 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

  18. 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

  19. 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

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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.

  5. 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.

  6. High-Efficiency Polycrystalline CdTe Thin-Film Solar Cells with an Oxygenated Amorphous CdS (a-CdS:O) Window Layer: Preprint

    SciTech Connect (OSTI)

    Wu, X.; Dhere, R. G.; Yan, Y.; Romero, M. J.; Zhang, Y.; Zhou, J.; DeHart, C.; Duda, A.; Perkins, C.; To, B.

    2002-05-01

    In the conventional CdS/CdTe device structure, the poly-CdS window layer has a bandgap of {approx}2.4 eV, which causes absorption in the short-wavelength region. Higher short-circuit current densities (Jsc) can be achieved by reducing the CdS thickness, but this can adversely impact device open-circuit voltage (Voc) and fill factor (FF). Also, poly-CdS film has about 10% lattice mismatch related to the CdTe film, which limits the improvement of device Voc and FF. In this paper, we report a novel window material: oxygenated amorphous CdS film (a-CdS:O) prepared at room temperature by rf sputtering. The a-CdS:O film has a higher optical bandgap (2.5-3.1 eV) than the poly-CdS film and an amorphous structure. The preliminary device results have demonstrated that Jsc of the CdTe device can be greatly improved while maintaining higher Voc and FF. We have fabricated a CdTe cell demonstrating an NREL-confirmed Jsc of 25.85 mA/cm2 and a total-area efficiency of 15.4%.

  7. 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...

  8. 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.

  9. Influence of different sulfur to selenium ratios on the structural and electronic properties of Cu(In,Ga)(S,Se){sub 2} thin films and solar cells formed by the stacked elemental layer process

    SciTech Connect (OSTI)

    Mueller, B. J.; Zimmermann, C.; Haug, V. Koehler, T.; Zweigart, S.; Hergert, F.; Herr, U.

    2014-11-07

    In this study, we investigate the effect of different elemental selenium to elemental sulfur ratios on the chalcopyrite phase formation in Cu(In,Ga)(S,Se){sub 2} thin films. The films are formed by the stacked elemental layer process. The structural and electronic properties of the thin films and solar cells are analyzed by means of scanning electron microscopy, glow discharge optical emission spectrometry, X-ray diffraction, X-ray fluorescence, Raman spectroscopy, spectral photoluminescence as well as current-voltage, and quantum efficiency measurements. The influence of different S/(S+Se) ratios on the anion incorporation and on the Ga/In distribution is investigated. We find a homogenous sulfur concentration profile inside the film from the top surface to the bottom. External quantum efficiency measurements show that the band edge of the solar cell device is shifted to shorter wavelength, which enhances the open-circuit voltages. The relative increase of the open-circuit voltage with S/(S+Se) ratio is lower than expected from the band gap energy trend, which is attributed to the presence of S-induced defects. We also observe a linear decrease of the short-circuit current density with increasing S/(S+Se) ratio which can be explained by a reduced absorption. Above a critical S/(S+Se) ratio of around 0.61, the fill factor drops drastically, which is accompanied by a strong series resistance increase which may be attributed to changes in the back contact or p-n junction properties.

  10. 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 ...

  11. Process and structures for fabrication of solar cells with laser ablation steps to form contact holes

    DOE Patents [OSTI]

    Harley, Gabriel; Smith, David D; Dennis, Tim; Waldhauer, Ann; Kim, Taeseok; Cousins, Peter John

    2013-11-19

    Contact holes of solar cells are formed by laser ablation to accomodate 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 thickness.

  12. 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.

  13. 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.

  14. 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...

  15. 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 ...

  16. 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 ...

  17. Low cost back contact heterojunction solar cells on thin c-Si wafers. Integrating laser and thin film processing for improved manufacturability

    SciTech Connect (OSTI)

    Hegedus, Steven S.

    2015-09-08

    An interdigitated back contact (IBC) Si wafer solar cell with deposited a-Si heterojunction (HJ) emitter and contacts is considered the ultimate single junction Si solar cell design. This was confirmed in 2014 by both Panasonic and Sharp Solar producing IBC-HJ cells breaking the previous record Si solar cell efficiency of 25%. But manufacturability at low cost is a concern for the complex IBC-HJ device structure. In this research program, our goals were to addressed the broad industry need for a high-efficiency c-Si cell that overcomes the dominant module cost barriers by 1) developing thin Si wafers synthesized by innovative, kerfless techniques; 2) integrating laser-based processing into most aspects of solar cell fabrication, ensuring high speed and low thermal budgets ; 3) developing an all back contact cell structure compatible with thin wafers using a simplified, low-temperature fabrication process; and 4) designing the contact patterning to enable simplified module assembly. There were a number of significant achievements from this 3 year program. Regarding the front surface, we developed and applied new method to characterize critical interface recombination parameters including interface defect density Dit and hole and electron capture cross-section for use as input for 2D simulation of the IBC cell to guide design and loss analysis. We optimized the antireflection and passivation properties of the front surface texture and a-Si/a-SiN/a-SiC stack depositions to obtain a very low (< 6 mA/cm2) front surface optical losses (reflection and absorption) while maintaining excellent surface passivation (SRV<5 cm/s). We worked with kerfless wafer manufacturers to apply defect-engineering techniques to improve bulk minority-carrier lifetime of thin kerfless wafers by both reducing initial impurities during growth and developing post-growth gettering techniques. This led insights about the kinetics of nickel, chromium, and dislocations in PV-grade silicon and to

  18. Low cost back contact heterojunction solar cells on thin c-Si wafers. integrating laser and thin film processing for improved manufacturability

    SciTech Connect (OSTI)

    Hegedus, Steven S.

    2015-09-08

    An interdigitated back contact (IBC) Si wafer solar cell with deposited a-Si heterojunction (HJ) emitter and contacts is considered the ultimate single junction Si solar cell design. This was confirmed in 2014 by both Panasonic and Sharp Solar producing IBC-HJ cells breaking the previous record Si solar cell efficiency of 25%. But manufacturability at low cost is a concern for the complex IBC-HJ device structure. In this research program, our goals were to addressed the broad industry need for a high-efficiency c-Si cell that overcomes the dominant module cost barriers by 1) developing thin Si wafers synthesized by innovative, kerfless techniques; 2) integrating laser-based processing into most aspects of solar cell fabrication, ensuring high speed and low thermal budgets ; 3) developing an all back contact cell structure compatible with thin wafers using a simplified, low-temperature fabrication process; and 4) designing the contact patterning to enable simplified module assembly. There were a number of significant achievements from this 3 year program. Regarding the front surface, we developed and applied new method to characterize critical interface recombination parameters including interface defect density Dit and hole and electron capture cross-section for use as input for 2D simulation of the IBC cell to guide design and loss analysis. We optimized the antireflection and passivation properties of the front surface texture and a-Si/a-SiN/a-SiC stack depositions to obtain a very low (< 6 mA/cm2) front surface optical losses (reflection and absorption) while maintaining excellent surface passivation (SRV<5 cm/s). We worked with kerfless wafer manufacturers to apply defect-engineering techniques to improve bulk minority-carrier lifetime of thin kerfless wafers by both reducing initial impurities during growth and developing post-growth gettering techniques. This led insights about the kinetics of nickel, chromium, and dislocations in PV-grade silicon and to

  19. Ascent Solar Technologies Inc | Open Energy Information

    Open Energy Info (EERE)

    Sector: Solar Product: Ascent Solar develops and plans to manufacture CIGS thin-film solar cells and modules for the satellite and high-altitude airship (HAA)...

  20. 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...

  1. 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.

  2. 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 ...

  3. 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.

  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 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

  8. 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

  9. 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.

  10. 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.

  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. 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

  15. 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.

  16. 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)

  17. 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.

  18. Polycrystalline MBE-grown GaAs for solar cells

    SciTech Connect (OSTI)

    Friedman, D.J.; Kurtz, S.R.; Kibbler, A.E.; Al-Jassim, M.; Jones, K.; Keyes, B.; Matson, R.

    1997-02-01

    This paper will discuss initial studies of thin-film GaAs grown by molecular-beam epitaxy for use in developing a thin-film GaAs solar cell. Photocurrent and photoluminescence intensity are related to the material morphology as a function of growth conditions. Growth temperature and V/III ratio have a dramatic effect on the photocurrent. However, it seems likely that even after optimizing such growth parameters, it will be necessary to provide substrates that can provide templates to enhance grain size from the start of thin-film growth. {copyright} {ital 1997 American Institute of Physics.}

  19. Polycrystalline MBE-grown GaAs for solar cells

    SciTech Connect (OSTI)

    Friedman, D. J.; Kurtz, Sarah R.; Kibbler, A. E.; Al-Jassim, M.; Jones, K.; Keyes, B.; Matson, R.

    1997-02-15

    This paper will discuss initial studies of thin-film GaAs grown by molecular-beam epitaxy for use in developing a thin-film GaAs solar cell. Photocurrent and photoluminescence intensity are related to the material morphology as a function of growth conditions. Growth temperature and V/III ratio have a dramatic effect on the photocurrent. However, it seems likely that even after optimizing such growth parameters, it will be necessary to provide substrates that can provide templates to enhance grain size from the start of thin-film growth.

  20. 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...

  1. 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

  2. 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.

  3. 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.

  4. 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...

  5. 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.

  6. 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;

  7. The impact of oxygen incorporation during intrinsic ZnO sputtering on the performance of Cu(In,Ga)Se{sub 2} thin film solar cells

    SciTech Connect (OSTI)

    Lee, Kkotnim; Ok, Eun-A; Park, Jong-Keuk; Kim, Won Mok; Baik, Young-Joon; Jeong, Jeung-hyun; Kim, Donghwan

    2014-08-25

    We investigated the impact of incorporating 2% oxygen during intrinsic ZnO sputtering on the efficiency of Cu(In,Ga)Se{sub 2} solar cells. The added oxygen not only reduced the optical absorption loss of the Al-doped ZnO overlaying layer but also improved the electronic properties of the underlying CdS/Cu(In,Ga)Se{sub 2} by increasing carrier density, lowering defect level, and increasing diffusion length, eventually enhancing J{sub SC}, V{sub OC}, and fill factor. It was found that the Na doping concentration was significantly increased around the CdS/Cu(In,Ga)Se{sub 2} junction due to the plasma-activated oxygen. The improved electronic properties are better explained by the increased Na concentration than simply the oxygen-related defect passivation.

  8. 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.

  9. 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.

  10. 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.