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Sample records for cigs solar cells

  1. Degradation of CIGS solar cells

    NARCIS (Netherlands)

    Theelen, M.J.

    2015-01-01

    Thin film CIGS solar cells and individual layers within these solar cells have been tested in order to assess their long term stability. Alongside with the execution of standard tests, in which elevated temperatures and humidity levels are used, the solar cells have also been exposed to a combinatio

  2. Device Modeling and Characterization for CIGS Solar Cells

    Science.gov (United States)

    Song, Sang Ho

    We studied the way to achieve high efficiency and low cost of CuIn1-xGaxSe2 (CIGS) solar cells. The Fowler-Nordheim (F-N) tunneling currents at low bias decreased the shunt resistances and degraded the fill factor and efficiency. The activation energies of majority traps were directly related with F-N tunneling currents by the energy barriers. Air anneals decreased the efficiency from 7.74% to 5.18% after a 150 °C, 1000 hour anneal. The decrease of shunt resistance due to F-N tunneling and the increase of series resistance degrade the efficiencies of solar cells. Air anneal reduces the free carrier densities by the newly generated Cu interstitial defects (Cui). Mobile Cui defects induce the metastability in CIGS solar cell. Since oxygen atoms are preferred to passivate the Se vacancies thus Cu interstitial defects explains well metastability of CIGS solar cells. Lattice mismatch and misfit stress between layers in CIGS solar cells can explain the particular effects of CIGS solar cells. The misfits of 35.08° rotated (220/204) CIGS to r-plane (102) MoSe2 layers are 1% ˜ -4% lower than other orientation and the lattice constants of two layers in short direction are matched at Ga composition x=0.35. This explains well the preferred orientation and the maximum efficiency of Ga composition effects. Misfit between CIGS and CdS generated the dislocations in CdS layer as the interface traps. Thermionic emission currents due to interface traps limit the open circuit voltage at high Ga composition. The trap densities were calculated by critical thickness and dislocation spacing and the numerical device simulation results were well matched with the experimental results. A metal oxide broken-gap p-n heterojunction is suggested for tunnel junction for multi-junction polycrystalline solar cells and we examined the characteristics of broken-gap tunnel junction by numerical simulation. Ballistic transport mechanism explains well I-V characteristics of broken-gap junction. P

  3. Integration of Solar Cells on Top of CMOS Chips - Part II: CIGS Solar Cells

    NARCIS (Netherlands)

    Lu, Jiwu; Liu, Wei; Kovalgin, Alexey Y.; Sun, Yun; Schmitz, Jurriaan

    2011-01-01

    We present the monolithic integration of deepsubmicrometer complementary metal–oxide–semiconductor (CMOS) microchips with copper indium gallium (di)selenide (CIGS) solar cells. Solar cells are manufactured directly on unpackaged CMOS chips. The microchips maintain comparable electronic performance,

  4. Flexible CIGS solar cells and mini-modules (Flexcim)

    Energy Technology Data Exchange (ETDEWEB)

    Tiwari, A. N.

    2007-08-15

    This final report for the Swiss Federal Office of Energy (SFOE) reports on a project that has contributed significantly to further developments in the field of Cu(In,Ga)Se{sub 2} thin film solar cells on flexible substrates such as plastic and metal foils. Process optimisation at low temperature deposition conditions is reported on that have resulted in a new world record of the highest achieved solar conversion efficiency for any solar cell on plastic substrate: cells with an efficiency of 14.1% were obtained. Efficiencies beyond 15% are to be sought for by the reduction of reflection losses. The results obtained are presented in both illustrations and in graphical form. The authors state that more work, especially on up-scaling of CIGS deposition and further increasing the efficiency of flexible solar modules, is needed.

  5. Monolithic DSSC/CIGS tandem solar cell fabricated by a solution process

    OpenAIRE

    Moon, Sung Hwan; Park, Se Jin; Kim, Sang Hoon; Lee, Min Woo; Han, Jisu; Kim, Jin Young; Kim, Honggon; Hwang, Yun Jeong; Lee, Doh-Kwon; Min, Byoung Koun

    2015-01-01

    Tandem architecture between organic (dye-sensitized solar cell, DSSC) and inorganic (CuInGaSe2 thin film solar cell, CIGS) single-junction solar cells was constructed particularly based on a solution process. Arc-plasma deposition was employed for the Pt interfacial layer to minimize the damage to the layers of the CIGS bottom cell. Solar cell efficiency of 13% was achieved, which is significant progress from individual single-junction solar cells (e.g., 7.25 and 6.2% for DSSC and CIGS, respe...

  6. Highly stable tandem solar cell monolithically integrating dye-sensitized and CIGS solar cells

    Science.gov (United States)

    Chae, Sang Youn; Park, Se Jin; Joo, Oh-Shim; Jun, Yongseok; Min, Byoung Koun; Hwang, Yun Jeong

    2016-01-01

    A highly stable monolithic tandem solar cell was developed by combining the heterogeneous photovoltaic technologies of dye-sensitized solar cell (DSSC) and solution-processed CuInxGa1-xSeyS1-y (CIGS) thin film solar cells. The durability of the tandem cell was dramatically enhanced by replacing the redox couple from to [Co(bpy)3]2+ /[Co(bpy)3]3+), accompanied by a well-matched counter electrode (PEDOT:PSS) and sensitizer (Y123). A 1000 h durability test of the DSSC/CIGS tandem solar cell in ambient conditions resulted in only a 5% decrease in solar cell efficiency. Based on electrochemical impedance spectroscopy and photoelectrochemical cell measurement, the enhanced stability of the tandem cell is attributed to minimal corrosion by the cobalt-based polypyridine complex redox couple. PMID:27489138

  7. All-Nonvacuum-Processed CIGS Solar Cells Using Scalable Ag NWs/AZO-Based Transparent Electrodes.

    Science.gov (United States)

    Wang, Mingqing; Choy, Kwang-Leong

    2016-07-01

    With record cell efficiency of 21.7%, CIGS solar cells have demonstrated to be a very promising photovoltaic (PV) technology. However, their market penetration has been limited due to the inherent high cost of the cells. In this work, to lower the cost of CIGS solar cells, all nonvacuum-processed CIGS solar cells were designed and developed. CIGS absorber was prepared by the annealing of electrodeposited metallic layers in a chalcogen atmosphere. Nonvacuum-deposited Ag nanowires (NWs)/AZO transparent electrodes (TEs) with good transmittance (92.0% at 550 nm) and high conductivity (sheet resistance of 20 Ω/□) were used to replace the vacuum-sputtered window layer. Additional thermal treatment after device preparation was conducted at 220 °C for a few of minutes to improve both the value and the uniformity of the efficiency of CIGS pixel cell on 5 × 5 cm substrate. The best performance of the all-nonvacuum-fabricated CIGS solar cells showed an efficiency of 14.05% with Jsc of 34.82 mA/cm(2), Voc of 0.58 V, and FF of 69.60%, respectively, which is comparable with the efficiency of 14.45% of a reference cell using a sputtered window layer. PMID:27299854

  8. An optimized efficient dual junction InGaN/CIGS solar cell: A numerical simulation

    Science.gov (United States)

    Farhadi, Bita; Naseri, Mosayeb

    2016-08-01

    The photovoltaic performance of an efficient double junction InGaN/CIGS solar cell including a CdS antireflector top cover layer is studied using Silvaco ATLAS software. In this study, to gain a desired structure, the different design parameters, including the CIGS various band gaps, the doping concentration and the thickness of CdS layer are optimized. The simulation indicates that under current matching condition, an optimum efficiency of 40.42% is achieved.

  9. Expanding Thermal Plasma Chemical Vapour Deposition of ZnO:Al Layers for CIGS Solar Cells

    Directory of Open Access Journals (Sweden)

    K. Sharma

    2014-01-01

    Full Text Available Aluminium-doped zinc oxide (ZnO:Al grown by expanding thermal plasma chemical vapour deposition (ETP-CVD has demonstrated excellent electrical and optical properties, which make it an attractive candidate as a transparent conductive oxide for photovoltaic applications. However, when depositing ZnO:Al on CIGS solar cell stacks, one should be aware that high substrate temperature processing (i.e., >200°C can damage the crucial underlying layers/interfaces (such as CIGS/CdS and CdS/i-ZnO. In this paper, the potential of adopting ETP-CVD ZnO:Al in CIGS solar cells is assessed: the effect of substrate temperature during film deposition on both the electrical properties of the ZnO:Al and the eventual performance of the CIGS solar cells was investigated. For ZnO:Al films grown using the high thermal budget (HTB condition, lower resistivities, ρ, were achievable (~5 × 10−4 Ω·cm than those grown using the low thermal budget (LTB conditions (~2 × 10−3 Ω·cm, whereas higher CIGS conversion efficiencies were obtained for the LTB condition (up to 10.9% than for the HTB condition (up to 9.0%. Whereas such temperature-dependence of CIGS device parameters has previously been linked with chemical migration between individual layers, we demonstrate that in this case it is primarily attributed to the prevalence of shunt currents.

  10. CIGS absorber layer with double grading Ga profile for highly efficient solar cells

    Science.gov (United States)

    Saadat, M.; Moradi, M.; Zahedifar, M.

    2016-04-01

    It is well-known that the band gap grading in CIGS solar cells is crucial for achieving highly efficient solar cells. We stimulate a CIGS solar cell and investigate the effects of the band gap grading on performance of the CIGS solar cell, where Ga/(Ga + In) ratio (GGI) at back (Cb) and front (Cf) of the absorber layer are considered constant. Our simulations show that by increasing the GGI at middle of CIGS absorber layer (Cm), the JSC decreases and VOC increases independent of the distance of the Cm from the back contact (Xm). For Cm lower than Cf, JSC increases and VOC decreases when the Xm shifts to the front of the CIGS layer. The behavior of JSC and VOC became reverse for the case of Cm greater than Cf. Almost in all of the structures, efficiency and FF have same behaviors. Our simulations show that the highest efficiency is obtained at Cm = 0.8 and Xm = 200 nm.

  11. Graded Carrier Concentration Absorber Profile for High Efficiency CIGS Solar Cells

    Directory of Open Access Journals (Sweden)

    Antonino Parisi

    2015-01-01

    Full Text Available We demonstrate an innovative CIGS-based solar cells model with a graded doping concentration absorber profile, capable of achieving high efficiency values. In detail, we start with an in-depth discussion concerning the parametrical study of conventional CIGS solar cells structures. We have used the wxAMPS software in order to numerically simulate cell electrical behaviour. By means of simulations, we have studied the variation of relevant physical and chemical parameters—characteristic of such devices—with changing energy gap and doping density of the absorber layer. Our results show that, in uniform CIGS cell, the efficiency, the open circuit voltage, and short circuit current heavily depend on CIGS band gap. Our numerical analysis highlights that the band gap value of 1.40 eV is optimal, but both the presence of Molybdenum back contact and the high carrier recombination near the junction noticeably reduce the crucial electrical parameters. For the above-mentioned reasons, we have demonstrated that the efficiency obtained by conventional CIGS cells is lower if compared to the values reached by our proposed graded carrier concentration profile structures (up to 21%.

  12. Investigation of Some Transparent Metal Oxides as Damp Heat Protective Coating for CIGS Solar Cells: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Pern, F. J.; Yan, F.; Zaaunbrecher, B.; To, B.; Perkins, J.; Noufi, R.

    2012-10-01

    We investigated the protective effectiveness of some transparent metal oxides (TMO) on CIGS solar cell coupons against damp heat (DH) exposure at 85oC and 85% relative humidity (RH). Sputter-deposited bilayer ZnO (BZO) with up to 0.5-um Al-doped ZnO (AZO) layer and 0.2-um bilayer InZnO were used as 'inherent' part of device structure on CdS/CIGS/Mo/SLG. Sputter-deposited 0.2-um ZnSnO and atomic layer deposited (ALD) 0.1-um Al2O3 were used as overcoat on typical BZO/CdS/CIGS/Mo/SLG solar cells. The results were all negative -- all TMO-coated CIGS cells exhibited substantial degradation in DH. Combining the optical photographs, PL and EL imaging, SEM surface micro-morphology, coupled with XRD, I-V and QE measurements, the causes of the device degradations are attributed to hydrolytic corrosion, flaking, micro-cracking, and delamination induced by the DH moisture. Mechanical stress and decrease in crystallinity (grain size effect) could be additional degrading factors for thicker AZO grown on CdS/CIGS.

  13. 铜铟镓硒(CIGS)薄膜太阳能电池的研究进展%Progress in Research of CIGS Thin Film Solar Cells

    Institute of Scientific and Technical Information of China (English)

    王波; 刘平; 李伟; 马凤仓; 刘新宽; 陈小红

    2011-01-01

    综述了CIGS薄膜太阳能电池近年来的研究进展.概述了CIGS薄膜的组织结构、性能特性及其之间的联系;介绍了CIGS薄膜吸收层的多种制备方法,如多元共蒸发法、溅射后硒化法、电沉积法、喷涂高温分解法等;概述了Na掺杂对CIGS电池性能的促进作用及其机理;总结了柔性衬底CIGS薄膜太阳能电池的研究情况;最后从理论和实验研究方面展望了CIGS薄膜太阳能电池的研究方向.%The recent progress of CIGS thin film solar cells is reviewed. The microstructure, properties and their relations of CIGS are summarized. Various preparation methods of CIGS absorber layer, such as co-evaporation, selenization after sputtering, electrodeposition, and spray pyrolysis etc are introduced. The influence of doping Na in performance and its mechanism of CIGS cells are summarized. The research of flexible CIGS cells are summed up, and the theoretical and experimental research directions of CIGS thin film solar cells are finally prospected.

  14. Recycling of high purity selenium from CIGS solar cell waste materials.

    Science.gov (United States)

    Gustafsson, Anna M K; Foreman, Mark R StJ; Ekberg, Christian

    2014-10-01

    Copper indium gallium diselenide (CIGS) is a promising material in thin film solar cell production. To make CIGS solar cells more competitive, both economically and environmentally, in comparison to other energy sources, methods for recycling are needed. In addition to the generally high price of the material, significant amounts of the metals are lost in the manufacturing process. The feasibility of recycling selenium from CIGS through oxidation at elevated temperatures was therefore examined. During oxidation gaseous selenium dioxide was formed and could be separated from the other elements, which remained in solid state. Upon cooling, the selenium dioxide sublimes and can be collected as crystals. After oxidation for 1h at 800°C all of the selenium was separated from the CIGS material. Two different reduction methods for reduction of the selenium dioxide to selenium were tested. In the first reduction method an organic molecule was used as the reducing agent in a Riley reaction. In the second reduction method sulphur dioxide gas was used. Both methods resulted in high purity selenium. This proves that the studied selenium separation method could be the first step in a recycling process aimed at the complete separation and recovery of high purity elements from CIGS.

  15. Sodium-Doped Molybdenum Targets for Controllable Sodium Incorporation in CIGS Solar Cells: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Mansfield, L. M.; Repins, I. L.; Glynn, S.; Carducci, M. D.; Honecker, D. M.; Pankow, J.; Young, M.; DeHart, C.; Sundaramoorthy, R.; Beall, C. L.; To, B.

    2011-07-01

    The efficiency of Cu(In,Ga)Se2 (CIGS) solar cells is enhanced when Na is incorporated in the CIGS absorber layer. This work examines Na incorporation in CIGS utilizing Na-doped Mo sputtered from targets made with sodium molybdate-doped (MONA) powder. Mo:Na films with varying thicknesses were sputtered onto Mo-coated borosilicate glass (BSG) or stainless steel substrates for CIGS solar cells. By use of this technique, the Na content of CIGS can be varied from near-zero to higher than that obtained from a soda-lime glass (SLG) substrate. Targets and deposition conditions are described. The doped Mo films are analyzed, and the resulting devices are compared to devices fabricated on Mo-coated SLG as well as Mo-coated BSG with NaF. Completed devices utilizing MONA exceeded 15.7% efficiency without anti-reflective coating, which was consistently higher than devices prepared with the NaF precursor. Strategies for minimizing adhesion difficulties are presented.

  16. The impact of atmospheric species on the degradation of CIGS solar cells

    NARCIS (Netherlands)

    Theelen, M.; Foster, C.; Steijvers, H.; Barreau, N.; Vroon, Z.; Zeman, M.

    2015-01-01

    CIGS solar cells were exposed to liquid water purged with the atmospheric gases carbon dioxide (CO2), oxygen (O2), nitrogen (N2) and air in order to investigate their chemical degradation behavior. The samples were analyzed by electrical, compositional and optical me

  17. Recycling of high purity selenium from CIGS solar cell waste materials

    International Nuclear Information System (INIS)

    Highlights: • A new method for recycling of selenium from CIGS solar cell materials is presented. • Separation of selenium as selenium dioxide after heating in oxygen atmosphere. • Complete selenium separation after oxidation of <63 μm particles at 800 °C for 1 h. • After reduction of selenium dioxide the selenium purity was higher than 99.999 wt%. - Abstract: Copper indium gallium diselenide (CIGS) is a promising material in thin film solar cell production. To make CIGS solar cells more competitive, both economically and environmentally, in comparison to other energy sources, methods for recycling are needed. In addition to the generally high price of the material, significant amounts of the metals are lost in the manufacturing process. The feasibility of recycling selenium from CIGS through oxidation at elevated temperatures was therefore examined. During oxidation gaseous selenium dioxide was formed and could be separated from the other elements, which remained in solid state. Upon cooling, the selenium dioxide sublimes and can be collected as crystals. After oxidation for 1 h at 800 °C all of the selenium was separated from the CIGS material. Two different reduction methods for reduction of the selenium dioxide to selenium were tested. In the first reduction method an organic molecule was used as the reducing agent in a Riley reaction. In the second reduction method sulphur dioxide gas was used. Both methods resulted in high purity selenium. This proves that the studied selenium separation method could be the first step in a recycling process aimed at the complete separation and recovery of high purity elements from CIGS

  18. Simulation of CIGS Thin Film Solar Cells Using AMPS-1D

    Directory of Open Access Journals (Sweden)

    J.R. Ray

    2011-01-01

    Full Text Available The solar cell structure based on copper indium gallium diselenide (CIGS as the absorber layer, cadmium sulfide (CdS as a buffer layer un-doped (i and Aluminium (Al doped zinc oxide (ZnO as a window layer was simulated using the one dimensional simulation program called analysis of microelectronic and photonic structures (AMPS-1D. In the simulation, the thickness of CIGS layer was varied from 300 to 3000 nm. The rest of layer’s thicknesses were kept constant, viz. 60 nm for CdS, and 80 nm and 500 nm for i- and Al-ZnO, respectively. By varying thickness of CIGS layer the simulated device performance was demonstrate in the form of current-voltage (I-V characteristics and quantum efficiency (QE.

  19. Impacts of electron irradiation on the optical and electrical properties of CIGS thin films and solar cells

    International Nuclear Information System (INIS)

    Full text : A thin film solar cell composed of polycrystalline Cu(In,Ga)Se2 (CIGS) is essentially light-weight and shows high conversion efficiency and excellent radiation tolerance. These characteristics lead to CIGS solar cells very attractive for space applications. However, only a few irradiation studies have been carried out on CIGS thin films and entire solar cell structure, resulting in limited knowledge on the mechanisms responsible for the irradiation-induced damage. In addition, the cell performance is known to change due to the damp heat and/or light soaking effects. Accordingly, understanding the degradation mechanisms of CIGS, ZnO, a buffer, Mo, and even glass components is necessary for not only space use but also commercial use. In this presentation, electron irradiation effects will be discussed for CIGS solar cells and each layer that composed the CIGS solar cell structure such as CIGS, CdS, undoped ZnO, and Ga- or Al-doped ZnO films. Electron irradiation experiments were carried out using the DYNAMITRON electron accelerator. The electron energy was fixed at 2 MeV and the fluence was varied between 1 * 1013 and 1 * 1018 cm-2. All the irradiated CIGS films exhibited common PL peaks originating from donor to acceptor transitions. PL peak intensity due to Cu-related point defects, which did not affect solar cell performance significantly, increased in CIGS thin films with increasing electron irradiation. Conversely, transmittance spectra of all the irradiated ZnO and ZnO:Al films did not change by the electron irradiation up to 6 * 1017 cm-2. The normalized performance parameters of the irradiated CIGS solar cell such as Voc, Jsc, and η are shown in article as a function of irradiation fluence. η tended to decrease in comparison with Voc and Jsc for large irradiation fluence. Shunt resistance and series resistance of the CIGS solar cells degraded even though the resistivity of each layer did not change after electron irradiation. The result

  20. Alternative back contact for CIGS solar cells built on sodium-free substrates

    OpenAIRE

    Söderström, Wilhelm

    2011-01-01

    It is widely known that the element sodium plays a vital role in providing highefficiency CIGS solar cells and that when cells are built on sodium free substrates theyneed an alternative (a substitute) sodium source. In this study a molybdenum-sodiumcompound has been deposited, investigated and evaluated as an alternative backcontact layer containing sodium. The compound had a 5 at % sodium concentrationand it was manufactured by an Austrian company called Plansee. The aim of the studywas to ...

  1. Characterization of carrier concentration in CIGS solar cells by scanning capacitance microscopy

    International Nuclear Information System (INIS)

    Thin films of copper indium gallium selenide (CIGS) designed for highly efficient solar cell material were investigated to characterize the two-dimensional carrier distribution using scanning capacitance microscopy (SCM). We optimized a preparation method of the cross-section samples and concluded that bevel polishing by 25° to 30° was effective for crumbly polycrystalline materials such as CIGS, so as to provide not the surface property of cracked crystalline grains but the cross-section property of individual cut grains. Because of improvement in this preparation procedure, changes in carrier distribution have been observed directly in the active CIGS layer before and after turning on a 100 W halogen lamp irradiation. A calibration curve between carrier concentration N and SCM's dC/dV signals was applied for qualitatively calculating relative values of N in CIGS. Increased carrier concentration peaks on the grains were estimated to become about three times as high as those with the light on. (paper)

  2. Ecotoxicological assessment of solar cell leachates: Copper indium gallium selenide (CIGS) cells show higher activity than organic photovoltaic (OPV) cells.

    Science.gov (United States)

    Brun, Nadja Rebecca; Wehrli, Bernhard; Fent, Karl

    2016-02-01

    Despite the increasing use of photovoltaics their potential environmental risks are poorly understood. Here, we compared ecotoxicological effects of two thin-film photovoltaics: established copper indium gallium selenide (CIGS) and organic photovoltaic (OPV) cells. Leachates were produced by exposing photovoltaics to UV light, physical damage, and exposure to environmentally relevant model waters, representing mesotrophic lake water, acidic rain, and seawater. CIGS cell leachates contained 583 μg L(-1) molybdenum at lake water, whereas at acidic rain and seawater conditions, iron, copper, zinc, molybdenum, cadmium, silver, and tin were present up to 7219 μg L(-1). From OPV, copper (14 μg L(-1)), zinc (87 μg L(-1)) and silver (78 μg L(-1)) leached. Zebrafish embryos were exposed until 120 h post-fertilization to these extracts. CIGS leachates produced under acidic rain, as well as CIGS and OPV leachates produced under seawater conditions resulted in a marked hatching delay and increase in heart edema. Depending on model water and solar cell, transcriptional alterations occurred in genes involved in oxidative stress (cat), hormonal activity (vtg1, ar), metallothionein (mt2), ER stress (bip, chop), and apoptosis (casp9). The effects were dependent on the concentrations of cationic metals in leachates. Addition of ethylenediaminetetraacetic acid protected zebrafish embryos from morphological and molecular effects. Our study suggests that metals leaching from damaged CIGS cells, may pose a potential environmental risk.

  3. Ecotoxicological assessment of solar cell leachates: Copper indium gallium selenide (CIGS) cells show higher activity than organic photovoltaic (OPV) cells.

    Science.gov (United States)

    Brun, Nadja Rebecca; Wehrli, Bernhard; Fent, Karl

    2016-02-01

    Despite the increasing use of photovoltaics their potential environmental risks are poorly understood. Here, we compared ecotoxicological effects of two thin-film photovoltaics: established copper indium gallium selenide (CIGS) and organic photovoltaic (OPV) cells. Leachates were produced by exposing photovoltaics to UV light, physical damage, and exposure to environmentally relevant model waters, representing mesotrophic lake water, acidic rain, and seawater. CIGS cell leachates contained 583 μg L(-1) molybdenum at lake water, whereas at acidic rain and seawater conditions, iron, copper, zinc, molybdenum, cadmium, silver, and tin were present up to 7219 μg L(-1). From OPV, copper (14 μg L(-1)), zinc (87 μg L(-1)) and silver (78 μg L(-1)) leached. Zebrafish embryos were exposed until 120 h post-fertilization to these extracts. CIGS leachates produced under acidic rain, as well as CIGS and OPV leachates produced under seawater conditions resulted in a marked hatching delay and increase in heart edema. Depending on model water and solar cell, transcriptional alterations occurred in genes involved in oxidative stress (cat), hormonal activity (vtg1, ar), metallothionein (mt2), ER stress (bip, chop), and apoptosis (casp9). The effects were dependent on the concentrations of cationic metals in leachates. Addition of ethylenediaminetetraacetic acid protected zebrafish embryos from morphological and molecular effects. Our study suggests that metals leaching from damaged CIGS cells, may pose a potential environmental risk. PMID:26615488

  4. A study on the optics of copper indium gallium (di)selenide (CIGS) solar cells with ultra-thin absorber layers

    NARCIS (Netherlands)

    Xu, M.; Wachters, A.J.H.; Deelen, J. van; Mourad, M.C.D.; Buskens, P.J.P.

    2014-01-01

    We present a systematic study of the effect of variation of the zinc oxide (ZnO) and copper indium gallium (di)selenide (CIGS) layer thickness on the absorption characteristics of CIGS solar cells using a simulation program based on finite element method (FEM). We show that the absorption in the CIG

  5. Characterizing the effects of silver alloying in chalcopyrite CIGS solar cells with junction capacitance methods

    Energy Technology Data Exchange (ETDEWEB)

    Erslev, Peter T.; Hanket, Gregory M.; Shafarman, William N.; Cohen, J. David

    2009-04-01

    A variety of junction capacitance-based characterization methods were used to investigate alloys of Ag into Cu(In1-xGax)Se2 photovoltaic solar cells over a broad range of compositions. These alloys show encouraging trends of increasing VOC with increasing Ag content, opening the possibility of wide-gap cells for use in tandem device applications. Drive level capacitance profiling (DLCP) has shown very low free carrier concentrations for all Ag-alloyed devices, in some cases less than 1014 cm-3, which is roughly an order of magnitude lower than that of CIGS devices. Transient photocapacitance spectroscopy has revealed very steep Urbach edges, with energies between 10 meV and 20 meV, in the Ag-alloyed samples. This is in general lower than the Urbach edges measured for standard CIGS samples and suggests a significantly lower degree of structural disorder.

  6. Simulation of the Efficiency of CdS/CIGS Tandem Multi-Junction Solar Cells Using AMPS-1D

    CERN Document Server

    Mirkamali, Ashrafalsadat S

    2016-01-01

    In this paper we conduct numerical simulation of CdS/CIGS solar cells by use of the AMPS-1D software aiming to formulate the optimal design of the new multi-junction tandem solar cell providing its most efficient operation. We start with the numerical simulation of single-junction CdS/CIGS solar cells, which shows that its highest efficiency of 17.3% could be achieved by the thickness of CIGS p-layer of 200 nm. This result is in a good agreement with experimental data where the highest efficiency was 17.1% with the solar cell thickness of 1 micron. By use of the results of the numerical simulation of the single-junction solar cells we developed the design and conducted optimization of the new multi-junction tandem CdS/CIGS solar cell structure. Numerical simulation shows that the maximum efficiency of this solar cell is equal to 48.3%, which could be obtained with the thickness of the CIGS p-layer of 600 nm at a standard illumination of AM 1.5.

  7. Semi-transparent perovskite solar cells for tandems with silicon and CIGS

    KAUST Repository

    Bailie, Colin D.

    2015-01-01

    © 2015 The Royal Society of Chemistry. A promising approach for upgrading the performance of an established low-bandgap solar technology without adding much cost is to deposit a high bandgap polycrystalline semiconductor on top to make a tandem solar cell. We use a transparent silver nanowire electrode on perovskite solar cells to achieve a semi-transparent device. We place the semi-transparent cell in a mechanically-stacked tandem configuration onto copper indium gallium diselenide (CIGS) and low-quality multicrystalline silicon (Si) to achieve solid-state polycrystalline tandem solar cells with a net improvement in efficiency over the bottom cell alone. This work paves the way for integrating perovskites into a low-cost and high-efficiency (>25%) tandem cell.

  8. Optical Metrology for CIGS Solar Cell Manufacturing and its Cost Implications

    Science.gov (United States)

    Sunkoju, Sravan Kumar

    Solar energy is a promising source of renewable energy which can meet the demand for clean energy in near future with advances in research in the field of photovoltaics and cost reduction by commercialization. Availability of a non-contact, in-line, real time robust process control strategies can greatly aid in reducing the gap between cell and module efficiencies, thereby leading to cost-effective large-scale manufacturing of high efficiency CIGS solar cells. In order to achieve proper process monitoring and control for the deposition of the functional layers of CuIn1-xGaxSe 2 (CIGS) based thin film solar cell, optical techniques such as spectroscopic reflectometry and polarimetry are advantageous because they can be set up in an unobtrusive manner in the manufacturing line, and collect data in-line and in-situ. The use of these techniques requires accurate optical models that correctly represent the properties of the layers being deposited. In this study, Spectroscopic ellipsometry (SE) has been applied for the characterization of each individual stage of CIGS layers deposited using the 3-stage co-evaporation process along with the other functional layers. Dielectric functions have been determined for the energy range from 0.7 eV to 5.1 eV. Critical-point line-shape analysis was used in this study to determine the critical point energies of the CIGS based layers. To control the compositional and thickness uniformity of all the functional layers during the fabrication of CIGS solar cells over large areas, multilayer photovoltaics (PV) stack optical models were developed with the help of extracted dielectric functions. In this study, mapping capability of RC2 spectroscopic ellipsometer was used to map all the functional layer thicknesses of a CIGS solar cell in order to probe the spatial non-uniformities that can affect the performance of a cell. The optical functions for each of the stages of CIGS 3-stage deposition process along with buffer layer and transparent

  9. Recent Progress in CIGS Thin Film Solar Cell Research at NREL: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Ramanathan, K.; Hasoon, F. S.; Al-Thani, H.; Alleman, J.; Keane, J.; Dolan, J.; Contreras, M. A.; Bhattacharya, R.; Noufi, R.

    2001-10-01

    Presented at the 2001 NCPV Program Review Meeting: This paper summarizes our work toward improving reproducibility in fabricating high efficiency absorbers and devices. This paper summarizes our work toward improving reproducibility in fabricating high efficiency absorbers and devices. This resulted in the fabrication of a CIGS cell with an efficiency of 21% under concentrated light. We compare devices fabricated with CdS and with Cd solution treatment alone. A high conversion efficiency of 15.7% is obtained with the latter, and we attribute this to the n-type doping afforded by Cd. The work is extended to absorbers provided by Siemens Solar Industries (SSI).

  10. Improvement in efficiency of solar cell by removing Cu2-xSe from CIGS film surface

    Institute of Scientific and Technical Information of China (English)

    Li Wei; Sun Yun; Liu Wei; Li Feng-Yan; Zhou Lin

    2006-01-01

    CIGS thin films are deposited by sputtering and selenization.The synthesis of semiconducting polycrystalline thin films and characteristics of devices based on the CIGS absorbing layers are investigated.Their microstructures are characterized by X-ray diffraction and Raman spectroscopy.The results reveal that there exist metallic Cu2-xSe compounds in CIGS film surfaces and the compounds are thought to be responsible for the degradation of the open circuit voltage of solar cells.The optimization of selenization temperature profile and copper content in the precursor surfaces is studied,concluding that the conversion efficiency may be improved by removing metallic Cu2-xSe compounds from the surfaces of CIGS thin films.

  11. Molybdenum Back-Contact Optimization for CIGS Thin Film Solar Cell

    Directory of Open Access Journals (Sweden)

    J.R. Ray

    2011-01-01

    Full Text Available Molybdenum (Mo thin films are most widely used as an ohmic back-contact in the copper indium diselenide (CIS and its alloy copper indium gallium diselenide (CIGS based thin film solar cell. Radio frequency (RF magnetron sputtering system used to deposit Mo thin films on soda lime glass substrate. The deposition was carried out using argon (Ar gas at different Ar controlled (working pressures (1 mTorr to 10 mTorr and at different RF powers (60 W to 100 W. The influence of both the working pressure and the RF power on the Mo thin films was studied by investigating its structural, morphological, electrical, and optical measurements. The results reveal that a stress-free, low-sheet-resistance (~1 Ω/cm2, and reflecting (~ 55 % Mo thin film was observed at 1 mTorr working pressure and 100 W RF power.

  12. CIGS Thin Film Solar Cells, phase 2 Uppsala University Final report 2006-01-01 - 2007-06-14

    Energy Technology Data Exchange (ETDEWEB)

    Edoff, Marika (Thin Film Solar Cell group, Dep. Technical Sciences, Uppsala Univ., P.O. Box 534, SE-751 21 Uppsala (Sweden)) (and others)

    2007-06-15

    The project CIGS Thin Film Solar Cells, phase 2 has been going on for 18,5 months and was interrupted in advance on the 14th of June, 2007. The decision to shorten the period was taken by the board of the Swedish Energy Agency the 14th of February. It was decided to reevaluate and re-direct the financial support to the group. A new project, CIGS Thin Film Solar Cells, phase 3, superseded this project and will go on for the initially planned project period (until 2009-12-31). During the project much of the focus has been on research on Cd-free buffer layers, with an emphasis on the interface properties between the CIGS and the buffer layer. (CIGS is a commonly used acronym for Cu(In,Ga)Se{sub 2}, which is the active absorption layer in this type of solar cells) The combination of high quality CIGS and the new buffer layers has been another field of interest. CIGS solar cell module development and computer modelling of solar cells and modules has been the third major research area. The results show that the group still holds a position as one of the leaders in the world in this field. The 18.5 % efficient Cd-free solar cell, which was obtained and independently confirmed is only one percent away from the world record and in addition it is Cd-free using a Zn(O,S) buffer layer (the world record from NREL contains Cd). By alloying ZnO with MgO instead of ZnS almost equally good results can be achieved. During the last half year an 18.1 % cell has been measured with a (Zn,Mg)O buffer layer. Solar cell module technology includes several research issues, both fundamental as e.g. modelling of cell voltage and losses as a function of distance from interconnect to interconnect, but also more development as e.g. encapsulation routines. The harsh environment test (damp heat test) run at 85 deg C and 85 % relative humidity for 1000 hours was passed for both a small (12.5x12.5 cm2) and a large (27.5x30 cm2) module within the degradation limits stated by the IEC standards, using

  13. Improving Performance of CIGS Solar Cells by Annealing ITO Thin Films Electrodes

    Directory of Open Access Journals (Sweden)

    Chuan Lung Chuang

    2015-01-01

    Full Text Available Indium tin oxide (ITO thin films were grown on glass substrates by direct current (DC reactive magnetron sputtering at room temperature. Annealing at the optimal temperature can considerably improve the composition, structure, optical properties, and electrical properties of the ITO film. An ITO sample with a favorable crystalline structure was obtained by annealing in fixed oxygen/argon ratio of 0.03 at 400°C for 30 min. The carrier concentration, mobility, resistivity, band gap, transmission in the visible-light region, and transmission in the near-IR regions of the ITO sample were -1.6E+20 cm−3, 2.7E+01 cm2/Vs, 1.4E-03 Ohm-cm, 3.2 eV, 89.1%, and 94.7%, respectively. Thus, annealing improved the average transmissions (400–1200 nm of the ITO film by 16.36%. Moreover, annealing a copper-indium-gallium-diselenide (CIGS solar cell at 400°C for 30 min in air improved its efficiency by 18.75%. The characteristics of annealing ITO films importantly affect the structural, morphological, electrical, and optical properties of ITO films that are used in solar cells.

  14. Simulation Study of Effects, Operating Temperature and Layer Thickness on Thin Film CIGS Solar Cell Performance

    Directory of Open Access Journals (Sweden)

    A.D. Pogrebnjak

    2011-01-01

    Full Text Available SCAPS- program is designed basically for the simulation and studying the properties of photonic devices. We explored the important controllable design parameters affecting the performance of the hetero junction solar cells, as operating temperature that we noticed increasing in J-V characteristics by increasing T, the effect of thickness of each layer on the performance of the cell was studied, an increasing of J-V characteristics with increasing p-layer , In the numerical example, 3 μm absorber layer and CdS layer 0.05 μm, ZnO layer 0.1 μm, works the best for given doping density, if we change the optimum value , the efficiency can reach to 17.72 % with FF 83.88 %, Voc = 0.725 Volt, Jsc = 29.07 mA/cm2 at 300 K, in this case, we have come out the optimum parameters to achieve the best performance of this type of cell, and then to made comparison with practical CIGS cell.

  15. Thin film solar cells based on CdTe and Cu(In,Ga)Se{sub 2} (CIGS) compounds

    Energy Technology Data Exchange (ETDEWEB)

    Gladyshev, P P [International University of Nature, Society and Man ' Dubna' , Dubna (Russian Federation); Filin, S V; Puzynin, A I; Tanachev, I A; Rybakova, A V; Tuzova, V V; Kozlovskiy, S A [Center of High Technologies of FSUE ' Applied Acoustics Research Institute' , Dubna (Russian Federation); Gremenok, V F; Mudryi, A V; Zaretskaya, E P [State Scientific and Production Association ' Scientific-Practical Materials, Researcher Center of National Academy of Sciences of Belarus' , Minsk (Belarus); Zalesskiy, V B; Kravchenko, V M; Leonova, U R; Khodin, A A; Pilipovich, V A; Polikanin, A M [Institute of Physics of National Academy of Sciences of Belarus, Minsk (Belarus); Khrypunov, G S; Chernyh, E P; Kovtun, N A [National Technical University ' Kharkov Politechnical Institute' , Kharkov (Ukraine); Belonogov, E K, E-mail: pavel.gladyshev@niipa.ru [Voronej State Technical University, Voronej (Russian Federation)

    2011-04-01

    We are publishing recent results in chalcogenide photoelectric convertors fabrication, which are efforts of many scientific teams from Russia, Belarus, Ukraine, and Kazakhstan. Competitively high efficiency of photoelectric convertors (11.4% for CdTe and 11% for CIGS) was achieved in the process of our work. Furthermore, luminescent filters for improvement of spectral response of such chalcogenide solar cells in a short wavelengths region were also developed and investigated here.

  16. Process parameter impact on properties of sputtered large-area Mo bilayers for CIGS thin film solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Badgujar, Amol C.; Dhage, Sanjay R., E-mail: dhage@arci.res.in; Joshi, Shrikant V.

    2015-08-31

    Copper indium gallium selenide (CIGS) has emerged as a promising candidate for thin film solar cells, with efficiencies approaching those of silicon-based solar cells. To achieve optimum performance in CIGS solar cells, uniform, conductive, stress-free, well-adherent, reflective, crystalline molybdenum (Mo) thin films with preferred orientation (110) are desirable as a back contact on large area glass substrates. The present study focuses on cylindrical rotating DC magnetron sputtered bilayer Mo thin films on 300 mm × 300 mm soda lime glass (SLG) substrates. Key sputtering variables, namely power and Ar gas flow rates, were optimized to achieve best structural, electrical and optical properties. The Mo films were comprehensively characterized and found to possess high degree of thickness uniformity over large area. Best crystallinity, reflectance and sheet resistance was obtained at high sputtering powers and low argon gas flow rates, while mechanical properties like adhesion and residual stress were found to be best at low sputtering power and high argon gas flow rate, thereby indicating a need to arrive at a suitable trade-off during processing. - Highlights: • Sputtering of bilayer molybdenum thin films on soda lime glass • Large area deposition using rotating cylindrical direct current magnetron • Trade of sputter process parameters power and pressure • High uniformity of thickness and best electrical properties obtained • Suitable mechanical and optical properties of molybdenum are achieved for CIGS application.

  17. Stability of CIGS solar cells and component materials evaluated by a step-stress accelerated degradation test method

    Science.gov (United States)

    Pern, F. J.; Noufi, R.

    2012-10-01

    A step-stress accelerated degradation testing (SSADT) method was employed for the first time to evaluate the stability of CuInGaSe2 (CIGS) solar cells and device component materials in four Al-framed test structures encapsulated with an edge sealant and three kinds of backsheet or moisture barrier film for moisture ingress control. The SSADT exposure used a 15°C and then a 15% relative humidity (RH) increment step, beginning from 40°C/40%RH (T/RH = 40/40) to 85°C/70%RH (85/70) as of the moment. The voluminous data acquired and processed as of total DH = 3956 h with 85/70 = 704 h produced the following results. The best CIGS solar cells in sample Set-1 with a moisture-permeable TPT backsheet showed essentially identical I-V degradation trend regardless of the Al-doped ZnO (AZO) layer thickness ranging from standard 0.12 μm to 0.50 μm on the cells. No clear "stepwise" feature in the I-V parameter degradation curves corresponding to the SSADT T/RH/time profile was observed. Irregularity in I-V performance degradation pattern was observed with some cells showing early degradation at low T/RH = 70/70. Results of (electrochemical) impedance spectroscopy (ECIS) analysis indicate degradation of the CIGS solar cells corresponded to increased series resistance Rs (ohm) and degraded parallel (minority carrier diffusion/recombination) resistance Rp, capacitance C, overall time constant Rp*C, and "capacitor quality" factor (CPE-P), which were related to the cells' p-n junction properties. Heating at 85/70 appeared to benefit the CIGS solar cells as indicated by the largely recovered CPE-P factor. Device component materials, Mo on soda lime glass (Mo/SLG), bilayer ZnO (BZO), AlNi grid contact, and CdS/CIGS/Mo/SLG in test structures with TPT showed notable to significant degradation at T/RH >= 70/70. At T/RH = 85/70, substantial blistering of BZO layers on CIGS cell pieces was observed that was not seen on BZO/glass, and a CdS/CIGS sample displayed a small darkening and then

  18. Stability of CIGS Solar Cells and Component Materials Evaluated by a Step-Stress Accelerated Degradation Test Method: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Pern, F. J.; Noufi, R.

    2012-10-01

    A step-stress accelerated degradation testing (SSADT) method was employed for the first time to evaluate the stability of CuInGaSe2 (CIGS) solar cells and device component materials in four Al-framed test structures encapsulated with an edge sealant and three kinds of backsheet or moisture barrier film for moisture ingress control. The SSADT exposure used a 15oC and then a 15% relative humidity (RH) increment step, beginning from 40oC/40%RH (T/RH = 40/40) to 85oC/70%RH (85/70) as of the moment. The voluminous data acquired and processed as of total DH = 3956 h with 85/70 = 704 h produced the following results. The best CIGS solar cells in sample Set-1 with a moisture-permeable TPT backsheet showed essentially identical I-V degradation trend regardless of the Al-doped ZnO (AZO) layer thickness ranging from standard 0.12 μm to 0.50 μm on the cells. No clear 'stepwise' feature in the I-V parameter degradation curves corresponding to the SSADT T/RH/time profile was observed. Irregularity in I-V performance degradation pattern was observed with some cells showing early degradation at low T/RH < 55/55 and some showing large Voc, FF, and efficiency degradation due to increased series Rs (ohm-cm2) at T/RH ≥ 70/70. Results of (electrochemical) impedance spectroscopy (ECIS) analysis indicate degradation of the CIGS solar cells corresponded to increased series resistance Rs (ohm) and degraded parallel (minority carrier diffusion/recombination) resistance Rp, capacitance C, overall time constant Rp*C, and 'capacitor quality' factor (CPE-P), which were related to the cells? p-n junction properties. Heating at 85/70 appeared to benefit the CIGS solar cells as indicated by the largely recovered CPE-P factor. Device component materials, Mo on soda lime glass (Mo/SLG), bilayer ZnO (BZO), AlNi grid contact, and CdS/CIGS/Mo/SLG in test structures with TPT showed notable to significant degradation at T/RH ≥ 70/70. At T/RH = 85/70, substantial blistering of

  19. Effect of deposition pressure on the properties of magnetron-sputter-deposited molybdenum back contacts for CIGS solar cells

    Science.gov (United States)

    Li, Weimin; Yan, Xia; Aberle, Armin G.; Venkataraj, Selvaraj

    2015-08-01

    Molybdenum (Mo) thin films were deposited onto soda-lime glass substrates by DC magnetron sputtering of a Mo target at various chamber pressures ranging from 1.5 × 10-3 to 7.5 × 10-3 mbar. The film properties were analysed with regards to their application as back electrode in copper indium gallium diselenide (CIGS) solar cells. It is observed that the resulting film morphology and microstructure were strongly affected by deposition pressure. Mo films deposited at a low pressure possess a high density and a low sheet resistance. These films also have a compact microstructure and a compressive strain, which lead to poor adhesion. The adhesion can be improved by increasing the chamber pressure, which has negative effects on the sheet resistance, optical reflection and porosity of the films. On the basis of these results, a method has been established to fabricate low-resistivity Mo films on soda-lime glass with very good adhesion for CIGS solar cell applications.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  1. Flexible CIGS solar cells on large area polymer foils with in-line deposition methods and application of alternative back contacts - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Tiwari, A. N.

    2009-08-15

    This illustrated report for the Swiss Federal Office of Energy (SFOE) summarises the work performed within this project and also reports on synergies with other projects that helped to make a significant contribution to the development of CIGS thin film solar cells on flexible substrates such as polymer foils. The project's aims were to learn more about up-scaling issues and to demonstrate the abilities required for the processing of layers on large area polyimide foils for flexible CIGS solar cells. Custom-built evaporators that were designed and constructed in-house are described. A CIGS system for in-line deposition was also modified for roll-to-roll deposition and alternative electrical back contacts to conventional ones were evaluated on flexible polyimide foils. The objectives of the project and the results obtained are looked at and commented on in detail.

  2. RESEARCH ON CIS AND CIGS THIN FILM SOLAR CELLS%CIS和CIGS薄膜太阳电池的研究

    Institute of Scientific and Technical Information of China (English)

    孙云; 王俊清; 杜兆峰; 舒保健; 于刚; 温国忠; 周祯华; 孙健; 李长健; 张丽珠

    2001-01-01

    P type CIS and CIGS thin films are fabricated by evaporating selenylation method,and so are N type CdS.They compose heterogeneity PN junction solar cells.After annealing,the cells'efficiencies reach 8.83%and 9.13% respectively.CIS Fabricating technology and key problems are discussed.The opinions about annealing are given in this article.%采用蒸发硒化方法制备了P型CIS(铜铟硒)和CIGS(铜铟镓硒)薄膜,用蒸发法制备N型CdS(硫化镉),二者组成异质PN结太阳电池。经退火处理,CIS和CIGS薄膜太阳电池的效率分别达到8.83%和9.13%。对制膜过程中衬底的选择,背电极的制备,CIS各元素蒸发控制和镓的掺入等工艺技术问题进行了深入的讨论,对电池的退火处理提出了自己的见解。

  3. High-temperature stability of molybdenum (Mo) back contacts for CIGS solar cells: a route towards more robust back contacts

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Ju-Heon; Yoon, Kwan-Hee; Jeong, Jeung-hyun [Solar Cell Research Center, Korea Institute of Science and Technology, 39-1, Seoul 136-791 (Korea, Republic of); Kim, Won Mok; Park, Jong-Keuk; Baik, Young-Joon [Electronic Materials Research Center, Korea Institute of Science and Technology, 39-1, Seoul 136-791 (Korea, Republic of); Seong, Tae-Yeon, E-mail: jhjeong@kist.re.kr [Department of Materials Science and Engineering, College of Engineering, Korea University, Seoul 136-701 (Korea, Republic of)

    2011-10-26

    The thermal stability of Mo thin films is indispensable to Cu(In,Ga)Se{sub 2} (CIGS) solar cells: CIGS films are deposited above 500 deg. C. The thermal stabilities of Mo thin films with dense to porous Mo microstructures, which are varied by controlling the sputtering pressure, are investigated. Interface failures are found to occur in buckling mode in denser Mo films, whereas cracking arises in less dense films. The failure modes are apparently dependent on the sign of the residual stress: the former is due to compressive stress, whereas the latter is due to tensile stress. Interestingly, the softening of soda-lime glass at high temperatures reconfigures the film stresses to be more compressive after annealing, which in turn triggers buckling even in films that are tensile-stressed in the as-deposited states. We conclude that the appropriate processing conditions for thermally stable back contacts cannot be obtained with the simple single layer approach. On the basis of this relationship between microstructure, residual stress and the failure modes, it is shown that improvements in film adhesion can widen the processing window for the preparation of robust back contacts, i.e. with a conventional bilayer approach and substrate roughening. Since the bilayer approach employed more compliant porous structures in the bottom layer, back contacts that are better suited to higher stress and temperature can be produced. Furthermore, substrate roughening might make the back contact more conductive as well as more stable because adhesion can be enhanced without the use of an electrically resistive buffer layer.

  4. The Effect of Sputtering Parameters on the Film Properties of Molybdenum Back Contact for CIGS Solar Cells

    Directory of Open Access Journals (Sweden)

    Peng-cheng Huang

    2013-01-01

    Full Text Available Molybdenum (Mo thin films are widely used as a back contact for CIGS-based solar cells. This paper determines the optimal settings for the sputtering parameters for an Mo thin film prepared on soda lime glass substrates, using direct current (dc magnetron sputtering, with a metal Mo target, in an argon gas environment. A Taguchi method with an L9 orthogonal array, the signal-to-noise ratio, and an analysis of variances is used to determine the performance characteristics of the coating operation. The main sputtering parameters, such as working pressure (mTorr, dc power (W, and substrate temperature (°C, are optimized with respect to the structural features, surface morphology, and electrical properties of the Mo films. An adhesive tape test is performed on each film to determine the adhesion strength of the films. The experimental results show that the working pressure has the dominant effect on electrical resistivity and reflectance. The intensity of the main peak (110 for the Mo film increases and the full width at half maximum decreases gradually as the sputtering power is increased. Additionally, the application of an Mo bilayer demonstrates good adherence and low resistivity.

  5. Photoelectrochemical water splitting for hydrogen production using combination of CIGS2 solar cell and RuO2 photocatalyst

    International Nuclear Information System (INIS)

    This paper presents the development of photoelectrochemical (PEC) cell for water splitting setup using multiple band gap combination of CuIn1-xGa xS2 (CIGS2) thin-film photovoltaic (PV) cell and ruthenium oxide (RuO2) photocatalyst. FSEC PV Materials Lab has developed a PEC setup consisting of two illuminated CIGS2 cells, a ruthenium oxide (RuO2) anode deposited on titanium sheet for oxygen evolution and a platinum foil cathode for hydrogen evolution. With this combination, a PEC efficiency of 4.29% has been achieved. This paper also presents the research aimed at further improvements in the PEC efficiency by employing highly efficient photoanode that can be illuminated by photons not absorbed at the PV cell and by increasing the concentration of electrolyte solution (pH 10). The former will be achieved by employing a p-type transparent and conducting layer at the back of PV cell to transmit the unabsorbed photons, and the latter will reduce the resistance offered by the electrolyte. Concentration of the electrolyte was increased by five times, and the I-V characteristics of both RuO2 and RuS2 were measured with and without illumination. The results indicate that PEC efficiencies of over 9% can be achieved using RuS2 with illumination and five times concentrated pH 10 solution instead of pH 10 with normal concentration

  6. Physics-Based Compact Model for CIGS and CdTe Solar Cells: From Voltage-Dependent Carrier Collection to Light-Enhanced Reverse Breakdown: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Xingshu; Alam, Muhammad Ashraful; Raguse, John; Garris, Rebekah; Deline, Chris; Silverman, Timothy

    2015-10-15

    In this paper, we develop a physics-based compact model for copper indium gallium diselenide (CIGS) and cadmium telluride (CdTe) heterojunction solar cells that attributes the failure of superposition to voltage-dependent carrier collection in the absorber layer, and interprets light-enhanced reverse breakdown as a consequence of tunneling-assisted Poole-Frenkel conduction. The temperature dependence of the model is validated against both simulation and experimental data for the entire range of bias conditions. The model can be used to characterize device parameters, optimize new designs, and most importantly, predict performance and reliability of solar panels including the effects of self-heating and reverse breakdown due to partial-shading degradation.

  7. In-situ growth of a CdS window layer by vacuum thermal evaporation for CIGS thin film solar cell applications

    International Nuclear Information System (INIS)

    Highly crystalline and transparent CdS films are grown by utilizing the vacuum thermal evaporation (VTE) method. The structural, surface morphological, and optical properties of the films are studied and compared with those prepared by chemical bath deposition (CBD). It is found that the films deposited at a high substrate temperature (200 °C) have a preferential orientation along (002) which is consistent with CBD-grown films. Absorption spectra reveal that the films are highly transparent and the optical band gap values are found to be in a range of 2.44 eV–2.56 eV. CuIn1−xGaxSe2 (CIGS) solar cells with in-situ VTE-grown CdS films exhibit higher values of Voc together with smaller values of Jsc than those from CBD. Eventually the conversion efficiency and fill factor become slightly better than those from the CBD method. Our work suggests that the in-situ thermal evaporation method can be a competitive alternative to the CBD method, particularly in the physical- and vacuum-based CIGS technology. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  8. High efficiency CIGS and CIS cells with CVD ZnO buffer layers

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, L.C.; Lei, W.; Addis, F.W. [Washington State Univ./Tri-Cities, Richland, WA (United States); Shafarman, W.N. [Univ. of Delaware, Newark, DE (United States). Inst. of Energy Conversion; Contreras, M.A.; Ramanathan, K. [National Renewable Energy Lab., Golden, CO (United States)

    1997-12-31

    This paper describes investigations of CIS and CIGS solar cells with ZnO buffer layers. These studies are a result of a team effort between investigators at Washington State University (WSU), the Institute of Energy Conversion (IEC) and the National Renewable Energy Laboratory (NREL). Cells with ZnO buffer layers were fabricated with both Siemens CIS and NREL CIGS substrates. An active area efficiency of 13.95% was achieved for a ZnO/CIGS cell. ZnO buffer layers are grown by reacting a zinc adduct with tetrahydrofuran using a two-step approach: growth of approximately 100 {angstrom} of ZnO at 250 C; and then growth of 500 to 700 {angstrom} of ZnO at 100 C. The high temperature step is necessary to achieve good cell performance. It appears that exposure of CIGS to hydrogen at 250 C may remove contaminants and/or passivate recombination centers on the surface and subsurface regions.

  9. Chemical deposition methods for Cd-free buffer layers in CI(G)S solar cells: Role of window layers

    International Nuclear Information System (INIS)

    It is currently possible to prepare Cd-free Cu(In,Ga)Se2-based solar cells with efficiencies similar or higher than their CdS references. In these cells, higher efficiencies are generally obtained from soft chemical-based techniques giving conformal depositions such as chemical bath deposition (CBD), ion layer gas reaction (ILGAR) or atomic layer deposition (ALD). However most of these devices are characterized by their pronounced transient behaviour. The aim of this paper is to compare these different chemical-based methods (CBD, ALD, ILGAR...) and to try to provide evidence for the dominant influence of the interface between the Cd-free buffer layer and the window layer on the performance and on the metastable electronic behaviour of these solar cells.

  10. Improving the efficiency of copper indium gallium (Di-selenide (CIGS solar cells through integration of a moth-eye textured resist with a refractive index similar to aluminum doped zinc oxide

    Directory of Open Access Journals (Sweden)

    M. Burghoorn

    2014-12-01

    Full Text Available Textured transparent conductors are widely used in thin-film silicon solar cells. They lower the reflectivity at interfaces between different layers in the cell and/or cause an increase in the path length of photons in the Si absorber layer, which both result in an increase in the number of absorbed photons and, consequently, an increase in short-circuit current density (Jsc and cell efficiency. Through optical simulations, we recently obtained strong indications that texturing of the transparent conductor in copper indium gallium (di-selenide (CIGS solar cells is also optically advantageous. Here, we experimentally demonstrate that the Jsc and efficiency of CIGS solar cells with an absorber layer thickness (dCIGS of 0.85 μm, 1.00 μm and 2.00 μm increase through application of a moth-eye textured resist with a refractive index that is sufficiently similar to AZO (nresist = 1.792 vs. nAZO = 1.913 at 633 nm to avoid large optical losses at the resist-AZO interface. On average, Jsc increases by 7.2%, which matches the average reduction in reflection of 7.0%. The average relative increase in efficiency is slightly lower (6.0%. No trend towards a larger relative increase in Jsc with decreasing dCIGS was observed. Ergo, the increase in Jsc can be fully explained by the reduction in reflection, and we did not observe any increase in Jsc based on an increased photon path length.

  11. Investigation of an Electrochemical Method for Separation of Copper, Indium, and Gallium from Pretreated CIGS Solar Cell Waste Materials

    Directory of Open Access Journals (Sweden)

    Anna M. K. Gustafsson

    2015-01-01

    Full Text Available Recycling of the semiconductor material copper indium gallium diselenide (CIGS is important to ensure a future supply of indium and gallium, which are relatively rare and therefore expensive elements. As a continuation of our previous work, where we recycled high purity selenium from CIGS waste materials, we now show that copper and indium can be recycled by electrodeposition from hydrochloric acid solutions of dissolved selenium-depleted material. Suitable potentials for the reduction of copper and indium were determined to be −0.5 V and −0.9 V (versus the Ag/AgCl reference electrode, respectively, using cyclic voltammetry. Electrodeposition of first copper and then indium from a solution containing the dissolved residue from the selenium separation and ammonium chloride in 1 M HCl gave a copper yield of 100.1 ± 0.5% and an indium yield of 98.1 ± 2.5%. The separated copper and indium fractions contained no significant contamination of the other elements. Gallium remained in solution together with a small amount of indium after the separation of copper and indium and has to be recovered by an alternative method since electrowinning from the chloride-rich acid solution was not effective.

  12. Non-Stoichiometric Amorphous Indium Selenide Thin Films as a Buffer Layer for CIGS Solar Cells with Various Temperatures in Rapid Thermal Annealing.

    Science.gov (United States)

    Yoo, Myoung Han; Kim, Nam-Hoon

    2016-05-01

    The conventional structure of most of copper indium gallium diselenide (Culn(1-x)Ga(x)Se2, CIGS) solar cells includes a CdS thin film as a buffer layer. Cd-free buffer layers have attracted great interest for use in photovoltaic applications to avoid the use of hazardous and toxic materials. The RF magnetron sputtering method was used with an InSe2 compound target to prepare the indium selenide precursor. Rapid thermal annealing (RTA) was conducted in ambient N2 gas to control the concentration of volatile Se from the precursor with a change in temperature. The nature of the RTA-treated indium selenide thin films remained amorphous under annealing temperatures of ≤ 700 degrees C. The Se concentration of the RTA-treated specimens demonstrated an opposite trend to the annealing temperature. The optical transmittance and band gap energies were 75.33% and 2.451-3.085 eV, respectively, and thus were suitable for the buffer layer. As the annealing temperature increased, the resistivity decreased by an order-of-magnitude from 10(4) to 10(1) Ω-cm. At lower Se concentrations, the conductivity abruptly changed from p-type to n-type without crystallite formation in the amorphous phase, with the carrier concentration in the order of 10(17) cm(-3). PMID:27483873

  13. Electrodeposition of Mg doped ZnO thin film for the window layer of CIGS solar cell

    Science.gov (United States)

    Wang, Mang; Yi, Jie; Yang, Sui; Cao, Zhou; Huang, Xiaopan; Li, Yuanhong; Li, Hongxing; Zhong, Jianxin

    2016-09-01

    Mg doped ZnO (ZMO) film with the tunable bandgap can adjust the conduction band offset of the window/chalcopyrite absorber heterointerface to positive to reduce the interface recombination and resulting in an increasement of chalcopyrite based solar cell efficiency. A systematic study of the effect of the electrodeposition potential on morphology, crystalline structure, crystallographic orientation and optical properties of ZMO films was investigated. It is interestingly found that the prepared doped samples undergo a significant morphological change induced by the deposition potential. With negative shift of deposition potential, an obvious morphology evolution from nanorod structrue to particle covered films was observed. A possible growth mechanism for explaining the morphological change is proposed and briefly discussed. The combined optical techniques including absorption, transmission and photoluminescence were used to study the obtained ZMO films deposited at different potential. The sample deposited at -0.9 V with the hexagonal nanorods morphology shows the highest optical transparency of 92%. The photoluminescence spectra reveal that the crystallization of the hexagonal nanorod ZMO thin film deoposited at -0.9 V is much better than the particles covered ZMO thin film. Combining the structural and optical properties analysis, the obtained normal hexagonal nanorod ZMO thin film could potentially be useful in nanostructured chalcopyrite solar cells to improve the device performance.

  14. Research Progress on Buffer Layer Materials of CIGS Thin Film Solar Cell%CIGS薄膜太阳能电池缓冲层材料的研究进展

    Institute of Scientific and Technical Information of China (English)

    王卫兵; 刘平; 李伟; 马凤仓; 刘新宽; 陈小红

    2012-01-01

    CIGS薄膜太阳能电池的缓冲层为低带隙CIGS吸收层与高带隙ZnO窗口层之间形成过渡,减少两者带隙的晶格失配和带隙失调,并可防止溅射ZnO窗口层时给CIGS吸收层带来损害等,对提高CIGS薄膜太阳能电池效率起了重要作用.介绍了CIGS薄膜太阳能电池缓冲层材料的分类和制备工艺,主要阐述了CdS、ZnS及In2S3薄膜缓冲层材料及化学水浴法、原子层化学气相沉积法、金属化合物化学气相沉积法等制备工艺的研究现状,最后指出CIGS太阳能电池缓冲层在制备工艺、环境保护及大规模工业化生产中遇到的问题,并展望了其发展方向.%The buffer layers of CTGS thin film solar cells can form transition layers between low band gap CIGS absorber layers and high band gap of ZnO window layers, which reduces the lattice matching and band gap difference, and prevents damage of CIGS absorber layer from sputtering ZnO window layer, and therefore plays an important role in improving efficiency of CIGS thin film solar cells. Classification and preparation technology of CIGS thim film solar cells material are discussed, including the research progress of CdS,ZnS and In2S3 thin film buffer layer materials, and chemical bath deposition (CBD), atomic layer chemical vapor deposition (ALCVD), metal organic chemical vapor deposition (MOCVD) and other preparation technologies. The problems and development directions of buffer layer materials of CIGS thin film solar cells in preparation process, environment protection and large-scale industrial production are finally prospected.

  15. E-Cigs May Damage Cells in Mouth

    Science.gov (United States)

    ... 159657.html E-Cigs May Damage Cells in Mouth Findings suggest a possible increase in the risk ... The oral cavity is the portion of the mouth behind the teeth and gums. The researchers believe ...

  16. Zn1-xMgxO用于CIGS太阳电池的研究进展%Developments of CIGS Solar Cells with Zn1-xMgxO Films

    Institute of Scientific and Technical Information of China (English)

    江秋怡; 王卿璞; 王汉斌; 王丹丹; 武丽伟; 李福杰

    2013-01-01

    Zn1-xMgxO透过率高、带隙可调,且与CIGS太阳电池在晶格和能带结构上匹配良好,可用作CIGS太阳电池缓冲层、窗口层,因此制备高质量的Zn1-xMgxO薄膜是提高太阳电池性能的关键.文章介绍了Zn1-xMgxO薄膜的结构特性、光学特性及制备方法;从Mg含量、Zn1-xMgxO膜厚及Zn1-xMgxO/CIGS界面处缺陷密度等方面概述了Zn1-xMgxO用于CIGS太阳电池的研究进展,并比较了Zn1-xMgxO与In2S3,ZnS,CdS等其他材料作缓冲层的CIGS太阳电池性能的差别.%With high transparency,adjustable band gap and good match with CIGS in lattice and energy band structure,Zn1-xMgxO is regarded as the suitable material for the buffer layer and window layer of CIGS solar cells,so the fabrication of high quality Zn1-xMgxO films becomes to be the key problem for improving the efficiency of CIGS solar cells.In this paper,the preparation methods and structural and optical characteristics of Zn1-xMgxO films are introduced;and also the effects of concentration of Mg,the film thickness and the defect density on solar cells are summarized.As well it is compared the performance of solar cells with Zn1-xMgxO buffer layer with those applying other buffer layer materials.

  17. Development of Electrodeposited CIGS Solar Cells: Cooperative Research and Development Final Report, CRADA Number CRD-09-357

    Energy Technology Data Exchange (ETDEWEB)

    Neale, Nathan [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-09-01

    At present, most PV materials are fabricated by vacuum technologies. Some of the many disadvantages of vacuum technology are complicated instrumentation, material waste, high cost of deposition per surface area, and instability of some compounds at the deposition temperature. Solution-based approaches for thin-film deposition on large areas are particularly desirable because of the low capital cost of the deposition equipment, relative simplicity of the processes, ease of doping, uniform deposition on a variety of substrates (including interior and exterior of tubes and various nonplanar devices), and potential compatibility with high-throughput (e.g., roll-to-roll) processing. Of the nonsilicon solar photovoltaic device modules that have been deployed to date, those based on the n-CdS/p-CdTe is a leading candidate. Two features in the optical characteristics of CdTe absorber are particularly attractive for photovoltaic conversion of sunlight; (a) its energy bandgap of 1.5 eV, which provides an optimal match with the solar spectrum and thus facilitates its efficient utilization and (b) the direct mode of the main optical transition which results in a large absorption coefficient and turn permits the use of thin layer (1-2 um) of active material. Thin films of CdTe required for these devices have been fabricated by a variety of methods (e.g., vapor transport deposition, vacuum deposition, screen printing and close-spaced sublimation). Electrodeposition is another candidate deserves more attention. This project will focus on delivering low-cost, high efficiency electrodeposited CdTe-based device.

  18. Design, development and manufacture of high-efficiency low-cost solar modules based on CIGS PVICs

    Science.gov (United States)

    Eldada, Louay

    2010-02-01

    We describe the design, development and manufacture of solar power panels based on photovoltaic integrated circuits (PVICs) with high-quality high-uniformity Copper Indium Gallium Selenide (CIGS) thin films produced with the unique combination of low-cost ink-based and physical vapor deposition (PVD) based nanoengineered precursor thin films and a reactive transfer printing method. Reactive transfer is a two-stage process relying on chemical reaction between two separate precursor films to form CIGS, one deposited on the substrate and the other on a printing plate in the first stage. In the second stage, these precursors are brought into intimate contact and rapidly reacted under pressure in the presence of an electrostatic field while heat is applied. The use of two independent thin films provides the benefits of independent composition and flexible deposition technique optimization, and eliminates pre-reaction prior to the synthesis of CIGS. High quality CIGS with large grains on the order of several microns, and of preferred crystallographic orientation, are formed in just several minutes based on compositional and structural analysis by XRF, SIMS, SEM and XRD. Cell efficiencies of 14% and module efficiencies of 12% have been achieved using this method. When atmospheric pressure deposition of inks is utilized for the precursor films, the approach additionally provides lower energy consumption, higher throughput, and further reduced capital equipment cost with higher uptime.

  19. Numerical Analysis of In2S3 Layer Thickness, Band Gap and Doping Density for Effective Performance of a CIGS Solar Cell Using SCAPS

    Science.gov (United States)

    Khoshsirat, Nima; Md Yunus, Nurul Amziah

    2016-11-01

    The effect of indium sulfide buffer layer's geometrical and electro-optical properties on the Copper-Indium-Gallium-diSelenide solar cell performance using numerical simulation is investigated. The numerical simulation software used is a solar cell capacitance simulator in (SCAPS). The innermost impacts of buffer layer thickness, band gap, and doping density on the cells output parameters such as open circuit voltage, short circuit current density, fill factor, and the efficiency were extensively simulated. The results show that the cell efficiency, which was innovatively illustrated as a two-dimensional contour plot function, depends on the buffer layer electron affinity and doping density by keeping all the other parameters at a steady state. The analysis, which was made from this numerical simulation, has revealed that the optimum electron affinity is to be 4.25 ± 0.2 eV and donor density of the buffer layer is over 1× 10 ^{17} cm^{-3}. It is also shown that the cell with an optimum thin buffer layer has higher performance and efficiency due to the lower optical absorption of the buffer layer.

  20. Nd:YAG laser annealing investigation of screen-printed CIGS layer on PET: Layer annealing method for photovoltaic cell fabrication process

    KAUST Repository

    Alsaggaf, Ahmed

    2014-06-01

    Cu(In, Ga)Se2 (CIGS) ink was formulated from CIGS powder, polyvinyl butyral PVB, terpineol and polyester/polyamine co-polymeric dispersant KD-1. Thin films with different thicknesses were deposited on PET substrate using screen-printing followed by heat treatment using a Nd:YAG laser. The structure and morphology of the heated thin films were studied. The characterization of the CIGS powder, ink, and film was done using TGA, SEM, FIB, EDS, and XRD. TGA analysis shows that the CIGS ink is drying at 200 °C, which is well below the decomposition temperature of the PET substrate. It was observed by SEM that 20 pulses of 532nm and 60 mJ/cm2 Nd:YAG laser annealing causes atomic diffusion on the near surface area. Furthermore, FIB cross section images were utilized to monitor the effect of laser annealing in the depth of the layer. Laser annealing effects were compared to as deposited layer using XRD in reference to CIGS powder. The measurement shows that crystallinity of deposited CIGS is retained while EDS quantification and atomic ratio result in gradual loss of selenium as laser energy increases. The laser parameters were tuned in an effort to utilize laser annealing of screen-printed CIGS layer as a layer annealing method for solar cell fabrication process.

  1. Efficiency enhancement in two-cell CIGS photovoltaic system with low-cost optical spectral splitter.

    Science.gov (United States)

    Maragliano, Carlo; Apostoleris, Harry; Bronzoni, Matteo; Rampino, Stefano; Stefancich, Marco; Chiesa, Matteo

    2016-01-25

    Spectrum splitting represents a valid alternative to multi-junction solar cells for broadband light-to-electricity conversion. While this concept has existed for decades, its adoption at the industrial scale is still stifled by high manufacturing costs and inability to scale to large areas. Here we report the experimental validation of a novel design that could allow the widespread adoption of spectrum splitting as a low-cost approach to high efficiency photovoltaic conversion. Our system consists of a prismatic lens that can be manufactured using the same methods employed for conventional CPV optic production, and two inexpensive CuInGaSe(2) (CIGS) solar cells having different composition and, thus, band gaps. We demonstrate a large improvement in cell efficiency under the splitter and show how this can lead to substantial increases in system output at competitive cost using existing technologies. PMID:26832577

  2. Cu(In,Ga)Se{sub 2} solar cells with superstrate structure using lift-off process

    Energy Technology Data Exchange (ETDEWEB)

    Osada, Shintaro; Anegawa, Takaya; Takakura, Hideyuki [College of Science and Engineering, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu 525-8577 (Japan); Abe, Yasuhiro; Minemoto, Takashi [Ritsumeikan Global Innovation Research Organization, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu 525-8577 (Japan)

    2011-01-15

    Cu(In,Ga)Se{sub 2} (CIGS) solar cells with a superstrate structure were fabricated using a lift-off process. To widen the variety of substrate choices for CIGS solar cells, a lift-off process was developed without an intentional sacrificial layer between the CIGS and Mo back-contact layers. The CIGS solar cells fabricated on Mo/soda-lime glass (SLG) were transferred to an alternative SLG substrate. The conversion efficiency of the CIGS solar cells with the superstrate structure was 5.1%, which was almost half that of the CIGS solar cells with a substrate structure prior to the lift-off process. The low conversion efficiency was caused by the high series resistance and low shunt resistance, which would be due to the junction resistance between the CIGS/back contact and cracks introduced during the lift-off process, respectively. (author)

  3. Peeled-off flexible Cu(In,Ga)Se2 solar cells and Na diffusion effects on cell performances

    Science.gov (United States)

    Sadono, Adiyudha; Ogihara, Tomohiro; Hino, Masashi; Yamamoto, Kenji; Yamada, Akira

    2016-07-01

    Na diffusion on Cu(In,Ga)Se2 (CIGS) solar cells fabricated on top of polyimide-coated soda-lime glass (SLG) substrate were investigated. Polyimide-coated SLG that can be used as substrate for fabricating flexible solar cells by peeled-off process, shown to have the same efficiency with SLG reference which is around 12%, indicating diffusion of almost same amount of Na from the substrates into the CIGS. Additional Na incorporation by NaF post-deposition treatment (PDT) were applied to CIGS deposited on substrates with different Na quantity to understand the Na diffusion effect prior and post CIGS deposition. Improvement of cells performance were observed for CIGS deposited on both substrates with or without Na diffusion. Final conversion efficiency of 15% was achieved after PDT for CIGS deposited on Na-contained substrates suggesting that PDT can be used even for CIGS with Na diffusion from the substrate. [Figure not available: see fulltext.

  4. A Novel Semiconductor CIGS Photovoltaic Material and Thin-Film ED Technology

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In order to achieve low-cost high-efficiency thin-film solar cells, a novel Semiconductor Photovoltaic (PV) active material CuIn1-xGaxSe2 (CIGS) and thin-film Electro-Deposition (ED) technology is explored. Firstly,the PV materials and technologies is investigated, then the detailed experimental processes of CIGS/Mo/glass structure by using the novel ED technology and the results are reported. These results shows that high quality CIGS polycrystalline thin-films can be obtained by the ED method, in which the polycrystalline CIGS is definitely identified by the (112), (204, 220) characteristic peaks of the tetragonal structure, the continuous CIGS thin-film layers with particle average size of about 2μm of length and around 1.6μm of thickness. The thickness and solargrade quality of CIGS thin-films can be produced with good repeatability. Discussion and analysis on the ED technique, CIGS energy band and sodium (Na) impurity properties, were also performed. The alloy CIGS exhibits not only increasing band-gap with increasing x, but also a change in material properties that is relevant to the device operation. The beneficial impurity Na originating from the low-cost soda-lime glass substrate becomes one prerequisite for high quality CIGS films. These novel material and technology are very useful for low-cost high-efficiency thin-film solar cells and other devices.

  5. Electrochemical etching of molybdenum for shunt removal in thin film solar cells

    NARCIS (Netherlands)

    Hovestad, A.; Bressers, P.M.M.C.; Meertens, R.M.; Frijters, C.H.; Voorthuijzen, W.P.

    2015-01-01

    High yield and reproducible production is a major challenge in up-scaling thin film Cu(In,Ga)Se2(CIGS) solar cells to large area roll-to-roll industrial manufacturing. Pinholes enabling Ohmic contact between the ZnO:Al front-contact and Mo back contact of the CIGS cell create electrical shunts that

  6. Cu(In,Ga)Se2 solar cells with controlled conduction band offset of window/Cu(In,Ga)Se2 layers

    International Nuclear Information System (INIS)

    Our group studied the effects of conduction band offset of window/Cu(In,Ga)Se2 (CIGS) layers on CIGS-based solar cell performance. To control the conduction band offset, we considered the use of a window layer of Zn1-xMgxO thin film with a controllable band gap as an alternative to the conventional window layer using CdS film. From the measurement of valence band offset between Zn1-xMgxO/CIGS layers and the band gap of each layer, we confirmed that the conduction band offset of Zn1-xMgxO/CIGS layers could be controlled by changing the Mg content of the Zn1-xMgxO film. The CIGS-based solar cells prepared for this study consisted of an ITO/Zn1-xMgxO/CIGS/Mo/soda-lime glass structure. When the conduction band minimum of Zn1-xMgxO was higher than that of CIGS, the performance of CIGS-based solar cells with a Zn1-xMgxO window layer was equivalent to that of CIGS-based solar cells with CdS window layers. We confirmed that the control of the conduction band offset of the window/CIGS layers decreases the majority carrier recombination via the Zn1-xMgxO/CIGS interface defects. [copyright] 2001 American Institute of Physics

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

    Science.gov (United States)

    Pudov, Alexei; Sites, James; Nakada, Tokio

    2002-06-01

    Chemically deposited ZnS has been investigated as a buffer layer alternative to cadmium sulfide (CdS) in polycrystalline thin-film Cu(In1-xGax)Se2 (CIGS) solar cells. Cells with efficiency of up to 18.1% based on chemical bath deposition (CBD)-ZnS{\\slash}CIGS heterostructures have been fabricated. This paper presents the performance and loss analyses of these cells based on the current-voltage (J-V) and spectral response curves, as well as comparisons with high efficiency CBD-CdS/CIGS and crystalline silicon counterparts. The CBD-ZnS/CIGS devices have effectively reached the efficiency of the current record CBD-CdS/CIGS cell. The effects of the superior current of the CBD-ZnS/CIGS cell and the superior junction quality of the CBD-CdS/CIGS cell on overall performance nearly cancel each other.

  8. Highly reflective rear surface passivation design for ultra-thin Cu(In,Ga)Se2 solar cells

    International Nuclear Information System (INIS)

    Al2O3 rear surface passivated ultra-thin Cu(In,Ga)Se2 (CIGS) solar cells with Mo nano-particles (NPs) as local rear contacts are developed to demonstrate their potential to improve optical confinement in ultra-thin CIGS solar cells. The CIGS absorber layer is 380 nm thick and the Mo NPs are deposited uniformly by an up-scalable technique and have typical diameters of 150 to 200 nm. The Al2O3 layer passivates the CIGS rear surface between the Mo NPs, while the rear CIGS interface in contact with the Mo NP is passivated by [Ga]/([Ga] + [In]) (GGI) grading. It is shown that photon scattering due to the Mo NP contributes to an absolute increase in short circuit current density of 3.4 mA/cm2; as compared to equivalent CIGS solar cells with a standard back contact. - Highlights: • Proof-of-principle ultra-thin CIGS solar cells have been fabricated. • The cells have Mo nano-particles (NPs) as local rear contacts. • An Al2O3 film passivates the CIGS rear surface between these nano-particles. • [Ga]/([Ga] + [In]) grading is used to reduce Mo-NP/CIGS interface recombination

  9. Barrier effect of AlN film in flexible Cu(In,Ga)Se2 solar cells on stainless steel foil and solar cell

    International Nuclear Information System (INIS)

    Highlights: • The adhension between AlN film and Mo are verygood. • AlN film can be effectively used as the barrier of flexible CIGS solar cell on SS substrate. • AlN film is suitable as the insulation barrier of flexible CIGS solar cell on SS substrate. - Abstract: The AlN film deposited by DC magnetron sputtering on stainless steel (SS) foils was used as the barrier in flexible Cu(In,Ga)Se2 (CIGS) solar cells on stainless steel foil and characterized comprehensively by X-ray diffraction (XRD), scanning electron microscopy (SEM), I–V, and QE measurements study. The study of AlN as insulation barrier in the flexible CIGS solar cell showed that the adhesion strength between the SS foil and the deposited AlN film was very strong even after annealing at high temperature at 530 °C. More importantly, a high resistance of over 10 MΩ was remained with the film with thickness of around 200 nm after annealing. This indicates that the AlN film is suitable as an effective insulation barrier in flexible CIGS solar cells based on SS foil. In addition, the XRD and SEM results showed that the AlN film did not influence the crystal structure of the Mo film which was deposited upon the AlN layer and used as the electrical contact in CIGS solar cells. It was found that the AlN film contributed to an improved crystallinity of the Mo contact layer compared to the bare SS foil. The combined results of secondary ion mass spectrometry, I–V and EQE measurements of the corresponding flexible CIGS solar cells confirmed that 1 μm-thick AlN film could be used as an efficient barrier layer in CIGS solar cells on SS foil

  10. Copper zinc tin sulfide-based thin film solar cells

    CERN Document Server

    Ito, Kentaro

    2014-01-01

    Beginning with an overview and historical background of Copper Zinc Tin Sulphide (CZTS) technology, subsequent chapters cover properties of CZTS thin films, different preparation methods of CZTS thin films, a comparative study of CZTS and CIGS solar cell, computational approach, and future applications of CZTS thin film solar modules to both ground-mount and rooftop installation. The semiconducting compound (CZTS) is made up earth-abundant, low-cost and non-toxic elements, which make it an ideal candidate to replace Cu(In,Ga)Se2 (CIGS) and CdTe solar cells which face material scarcity and tox

  11. Advances in thin-film solar cells

    CERN Document Server

    Dharmadasa, I M

    2012-01-01

    This book concentrates on the latest developments in our understanding of solid-state device physics. The material presented is mainly experimental and based on CdTe thin-film solar cells. It extends these new findings to CIGS thin-film solar cells and presents a new device design based on graded bandgap multilayer solar cells. This design has been experimentally tested using the well-researched GaAs/AlGaAs system and initial devices have shown impressive device parameters. These devices are capable of absorbing all radiation (UV, visible, and infra-red) within the solar spectrum and combines

  12. Characterization of Damp-Heat Degradation of CuInGaSe2 Solar Cell Components and Devices by (Electrochemical) Impedance Spectroscopy: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Pern, F. J. J.; Noufi, R.

    2011-09-01

    This work evaluated the capability of (electrochemical) impedance spectroscopy (IS, or ECIS as used here) to monitor damp heat (DH) stability of contact materials, CuInGaSe2 (CIGS) solar cell components, and devices. Cell characteristics and its variation of the CIGS devices were also examined by the ECIS.

  13. Analysis of Effects Resulted from Changing the Buffer Layer Material on Optimization of Cu (In 1-x,Gax Se2 Thin Filmsolar cell(CIGS and Simulation of Cell Structure

    Directory of Open Access Journals (Sweden)

    Nafise Shams

    2013-12-01

    Full Text Available Due tothe present globalunderstandingabout utilization ofrenewable energysources as constantcleanones, PVpowerhas beenthefocused bymanyresearch centers. Research of developmentofPhotovoltaic Energyis generally done in tow fields:reducingcosts andincreasing efficiency. CIGS thin film solar cells are of particular importance among the other types of the same category, due to the flexibility and yields of about 20%.Thispaper examines theperformance ofnanostructuredCIGSsolarcellsare discussed. The impact of changing material in the buffer layer of cell structure on electrical properties and the overall performance is evaluated. The optimized efficiency is also determined using simulation tools.

  14. Effect of rear-surface buffer layer on performance of lift-off Cu(In,Ga)Se2 solar cells

    Science.gov (United States)

    Aoyagi, Kenta; Tamura, Akihiro; Takakura, Hideyuki; Minemoto, Takashi

    2014-01-01

    The effect of an Au and MoOx rear-surface buffer layer inserted between Cu(In,Ga)Se2 (CIGS) and ZnO:Al on solar cell performances was examined. The lift-off CIGS solar cell without a rear-surface buffer layer showed particular characteristics of two series-connected diodes in the reverse direction, and its short-circuit current density was almost zero. In contrast, the Au or MoOx rear-surface buffer layer improved these characteristics. Although the lift-off CIGS solar cell with the Au rear-surface buffer layer showed shunt characteristics and low efficiency, the efficiency of the lift-off CIGS solar cell with the MoOx rear-surface buffer layer was approximately 50% of that of substrate-type CIGS solar cells. Diode parameters of lift-off CIGS solar cells were determined by fitting analysis of current density-voltage curves using a proposed new equivalent circuit model for lift-off CIGS solar cells.

  15. Investigation of the effects of rear surface recombination on the Cu(In,Ga)Se2 solar cell performances

    Science.gov (United States)

    Umehara, Takeshi; Iinuma, Shohei; Yamada, Akira

    2016-07-01

    This study investigated the band profile design of Cu(In,Ga)Se2 (CIGS) solar cells by considering the rear surface recombination. We compared the structures assuming the back surface field (BSF), passivation and graded band profile by using device simulator. As a result, it was found that the band structure of a combination of a flat-band and a single-graded profile is the suitable structure for CIGS solar cells with the absorber thickness of around 1.0 μm. In addition, the back passivation technique is unnecessary in the case of CIGS solar cells with a band profiling technique. We proposed that the band structure of a combination of a flat-band and a single-graded profile is the most practical and effective way for CIGS solar cells. [Figure not available: see fulltext.

  16. Distortions to current-voltage curves of cigs cells with sputtered Zinc(Oxygen,Sulfur) buffer layers

    Science.gov (United States)

    Song, Tao

    Sputtered-deposited Zn(O,S) is an attractive alternative to CdS for Cu(In,Ga)Se 2 (CIGS) thin-film solar cells' buffer layer. It has a higher band gap and thus allows greater blue photon collection to achieve higher photon current. The primary goal of the thesis is to investigate the effects of the secondary barrier at the buffer-absorber interface on the distortions to current-voltage (J-V) curves of sputtered-Zn(O,S)/CIGS solar cells. A straightforward photodiode model is employed in the numerical simulation to explain the physical mechanisms of the experimental J-V distortions including J-V crossover and red kink. It is shown that the secondary barrier is influenced by both the internal material properties, such as the conduction-band offset (CBO) and the doping density of Zn(O,S), and the external conditions, such as the light intensity and operating temperature. A key parameter for the sputter deposition of Zn(O,S) has been the oxygen fraction in the argon beam. It is found that the CBO varies with the oxygen fraction in the argon beam at a fixed temperature. With a greater CBO (DeltaEC>0.3 eV), the resulting energy barrier limits the electron current flowing across the interface and thus leads to the J-V distortion. Two different ZnS targets, non-indium and indium-doped one, were used to deposit the Zn(O,S) buffer layer. At the same oxygen fraction in argon beam, a non-In-doped Zn(O,S) buffer with a smaller amount of doping forms a greater secondary barrier to limit the electron current due to the compensation of the Zn(O,S) buffer layer. In addition, the temperature-dependent J-V crossover can be explained by the temperature-dependent impact of the secondary barrier - at lower temperature in the dark, the maximum distortion-free barrier is reduced and results in a more serious current limitation, indicating a greater J-V crossover. It is also found that, under low-intensity illumination, there is a lower doping density of Zn(O,S) due to a smaller amount of

  17. Spatial atmospheric ALD of functional layers for CIGS Solar Cells

    NARCIS (Netherlands)

    Illiberi, A.; Frijters, C.; Balder, J.E.; Poodt, P.W.G.; Roozeboom, F.

    2015-01-01

    Spatial Atmosperic Atomic Layer Depositon combines the advantages of temporal ALD, i.e. excellent control of film composition and uniformity over large area substrates, with high growth rages (up tot nm/s). In this paper we present a short overview of our research acctivity carried out on S-ALD of f

  18. Enhanced Conversion Efficiency of Cu(In,Ga)Se2 Solar Cells via Electrochemical Passivation Treatment.

    Science.gov (United States)

    Tsai, Hung-Wei; Thomas, Stuart R; Chen, Chia-Wei; Wang, Yi-Chung; Tsai, Hsu-Sheng; Yen, Yu-Ting; Hsu, Cheng-Hung; Tsai, Wen-Chi; Wang, Zhiming M; Chueh, Yu-Lun

    2016-03-01

    Defect control in Cu(In,Ga)Se2 (CIGS) materials, no matter what the defect type or density, is a significant issue, correlating directly to PV performance. These defects act as recombination centers and can be briefly categorized into interface recombination and Shockley-Read-Hall (SRH) recombination, both of which can lead to reduced PV performance. Here, we introduce an electrochemical passivation treatment for CIGS films that can lower the oxygen concentration at the CIGS surface as observed by X-ray photoelectron spectrometer analysis. Temperature-dependent J-V characteristics of CIGS solar cells reveal that interface recombination is suppressed and an improved rollover condition can be achieved following our electrochemical treatment. As a result, the surface defects are passivated, and the power conversion efficiency performance of the solar cell devices can be enhanced from 4.73 to 7.75%.

  19. Degradation mechanism of Cu(In,Ga)Se2 solar cells induced by exposure to air

    Science.gov (United States)

    Nishinaga, Jiro; Kamikawa, Yukiko; Koida, Takashi; Shibata, Hajime; Niki, Shigeru

    2016-07-01

    The degradation mechanism of unencapsulated Cu(In,Ga)Se2 (CIGS) solar cells upon exposure to air has been investigated. Exposure to air at room temperature slightly reduces the conversion efficiency of CIGS solar cells. However, this conversion efficiency decreases significantly under damp heat testing at 85 °C and a relative humidity of 85% for 15 h. The shunt resistance and conversion efficiency are completely recovered after removing the side edges of the CIGS solar cells by mechanical scribing. This result suggests that low-resistive layers are formed on the sidewalls of the solar cells during damp heat testing. In addition, alkaline solution etching has been confirmed to be an effective way of removing the low-resistive layers. The low-resistive layers on the sidewalls are identified to be molybdenum oxides and sodium molybdate by Auger electron spectroscopy. After etching the oxides on the sidewalls, the saturation current density and ideality factor are confirmed to be improved.

  20. Thin-film solar cells on perlite glass-ceramic substrates

    Science.gov (United States)

    Petrosyan, Stepan G.; Babayan, Virab H.; Musayelyan, Ashot S.; Harutyunyan, Levon A.; Zalesski, Valery B.; Kravchenko, Vladimir M.; Leonova, Tatyana R.; Polikanin, Alexander M.; Khodin, Alexander A.

    2013-06-01

    For the first time, thin-film CIGS solar cells have been fabricated by co-evaporation on specially developed non-conducting perlite (an aluminum potassium sodium silicate natural mineral of volcanic origin) glass-ceramic substrates to develop a fully integrated photovoltaic and building element. Such glass-ceramic material can meet the physical requirements to solar cells substrates as well as the cost goals. The preliminary data presented show that CIGS solar cells deposited on ceramic substrates can exhibit efficiency higher than 10%.

  1. Flexible Cu(In,Ga)Se2 thin-film solar cells%柔性铜铟镓硒薄膜太阳电池

    Institute of Scientific and Technical Information of China (English)

    闫礼; 乔在祥

    2011-01-01

    The general structure and researching status of flexible Cu (In,Ga)Se2 (CIGS) thin-film solar cells was described.The crucial technologies and challenges in the development of flexible CIGS solar cells were also involved.%介绍了柔性铜铟镓硒薄膜太阳电池的基本结构、研究现况、关键技术,同时指出了未来面临的挑战.

  2. Ultrafast pump-probe reflectance spectroscopy: Why sodium makes Cu(In,Ga)Se2 solar cells better

    KAUST Repository

    Eid, Jessica

    2015-04-14

    Although Cu(In,Ga)Se2 (CIGS) solar cells have the highest efficiency of any thin-film solar cell, especially when sodium is incorporated, the fundamental device properties of ultrafast carrier transport and recombination in such cells remain not fully understood. Here, we explore the dynamics of charge carriers in CIGS absorber layers with varying concentrations of Na by femtosecond (fs) broadband pump-probe reflectance spectroscopy with 120 fs time resolution. By analyzing the time-resolved transient spectra in a different time domain, we show that a small amount of Na integrated by NaF deposition on top of sputtered Cu(In,Ga) prior to selenization forms CIGS, which induces slower recombination of the excited carriers. Here, we provide direct evidence for the elongation of carrier lifetimes by incorporating Na into CIGS.

  3. Solar cells

    Science.gov (United States)

    Cuquel, A.; Roussel, M.

    The physical and electronic characteristics of solar cells are discussed in terms of space applications. The principles underlying the photovoltaic effect are reviewed, including an analytic model for predicting the performance of individual cells and arrays of cells. Attention is given to the effects of electromagnetic and ionizing radiation, micrometeors, thermal and mechanical stresses, pollution and degassing encountered in space. The responses of different types of solar cells to the various performance-degrading agents are examined, with emphasis on techniques for quality assurance in the manufacture and mounting of Si cells.

  4. The influence of Na on metastable defect kinetics in CIGS materials

    Energy Technology Data Exchange (ETDEWEB)

    Erslev, Peter T. [University of Oregon Physics Department, Eugene, Oregon (United States)], E-mail: perslev@uoregon.edu; Lee, Jin Woo [University of Oregon Physics Department, Eugene, Oregon (United States); Shafarman, William N. [Institute of Energy Conversion, University of Delaware, Newark, Delaware (United States); Cohen, J. David [University of Oregon Physics Department, Eugene, Oregon (United States)

    2009-02-02

    The electronic properties of matched pairs of Cu(In{sub x}Ga{sub 1-x})Se{sub 2} (CIGS) solar cells, with and without normal sodium levels, were studied by junction capacitance methods including admittance spectroscopy, drive level capacitance profiling (DLCP) and transient photocapacitance spectroscopy (TPC). The capacitance profiling measurements revealed a large deep defect density in the vicinity of the barrier interface that was likely responsible for the lower performance of the reduced Na samples. The metastable properties of CIGS solar cells were also examined, and these revealed marked differences between the two types of samples. These results directly address the predictions of theoretical microscopic models that have been proposed to account for metastable effects in CIGS.

  5. Effect of Rapid Thermal Annealing of CIGS Thin Film as an Absorber Layer

    Directory of Open Access Journals (Sweden)

    J.R. Ray

    2013-05-01

    Full Text Available The influence of rapid post-deposition thermal annealing (500 °C for 2 minutes on the CIGS thin films of different thicknesses (0.4 to 1.0 m has been investigated. The deposition of CIGS is carried out using the flash evaporation at the substrate temperature of 250 °C. The as-grown and annealed CIGS is characterized by XRD, SEM, EDS, TEM, optical transmission, reflection, and electrical measurements. Lowering the thickness of CIGS absorber shows the remarkable influence on crystal structure, surface morphology, and composition of the overall film. Further improvement was observed by the rapid annealing process. Cu-rich composition was observed for annealed CIGS thin film having a thickness below 0.6 μm, while for 1.0 m thickness the composition is slightly Cu-poor and the compactly packed faceted grains observed. Optical band gap near to 1.05 eV and the electrical resistivity in the order of 104 Ωcm shows its future use as an absorber layer for CIGS solar cell. Furthermore, an attempt of making CIGS / CdS hetero-structure shows ideal behavior of the Schottky hetero-structure with the ideality factor of 1.5.

  6. Optical and electrical properties of electron-irradiated Cu(In,Ga)Se{sub 2} solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Hirose, Y.; Warasawa, M. [Department of Electrical Engineering, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda 278-8510 (Japan); Takakura, K. [Department of Information, Communication and Electrical Engineering, Kumamoto National College of Technology, 2659-2 Suya, Koshi, Kumamoto 861-1102 (Japan); Kimura, S. [Department of Electrical Engineering, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda 278-8510 (Japan); Chichibu, S.F. [CANTech, Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba, Sendai 980-8577 (Japan); Ohyama, H. [Department of Information, Communication and Electrical Engineering, Kumamoto National College of Technology, 2659-2 Suya, Koshi, Kumamoto 861-1102 (Japan); Sugiyama, M., E-mail: mutsumi@rs.noda.tus.ac.jp [Department of Electrical Engineering, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda 278-8510 (Japan)

    2011-08-31

    The optical and electrical properties of electron-irradiated Cu(In,Ga)Se{sub 2} (CIGS) solar cells and the thin films that composed the CIGS solar cell structure were investigated. The transmittance of indium tin oxide (ITO), ZnO:Al, ZnO:Ga, undoped ZnO, and CdS thin films did not change for a fluence of up to 1.5 x 10{sup 18} cm{sup -2}. However, the resistivity of ZnO:Al and ZnO:Ga, which are generally used as window layers for CIGS solar cells, increased with increasing irradiation fluence. For CIGS thin films, the photoluminescence peak intensity due to Cu-related point defects, which do not significantly affect solar cell performance, increased with increasing electron irradiation. In CIGS solar cells, decreasing J{sub SC} and increasing R{sub s} reflected the influence of irradiated ZnO:Al, and decreasing V{sub OC} and increasing R{sub sh} mainly tended to reflect the pn-interface properties. These results may indicate that the surface ZnO:Al thin film and several heterojunctions tend to degrade easily by electron irradiation as compared with the bulk of semiconductor-composed solar cells.

  7. Process Development for CIGS-Based Thin-Film Photovoltaic Modules; Phase I Technical Report, 5 February 1998--4 February 1999

    Energy Technology Data Exchange (ETDEWEB)

    Britt, J., Wiedeman, S.; Wendt, R.; Albright, S.

    1999-09-13

    This report describes work performed by Global Solar Energy (GSE) under Phase I of this subcontract. GSE has initiated an extensive and systematic plan to accelerate the commercialization of thin-film photovoltaics (PV) on copper indium gallium diselenide (CIGS). GSE is developing the technology to deposit and monolithically integrate CIGS photovoltaics on a flexible substrate. CIGS-deposited on flexible substrates can be fabricated into either flexible or rigid modules. Low-cost, rigid PV panels for remote power, bulk/utility, telecommunications, and rooftop applications will be produced by affixing the flexible CIGS to an expensive rigid panel by lamination or adhesive. In the GSE approach, long (up to 700 m) continuous rolls of substrate are processed, as opposed to individual small glass plates. In combination with roll-to-roll processing, GSE is developing evaporation deposition operations that enable low-cost and high-efficiency CIGS modules. Efforts are under way to transition the CIGS deposition process into manufacturing at GSE. CIGS process development is focused on synchronizing the operation of the effusion sources, the Se delivery profile, substrate temperature, and a host of other parameters. GSE has selected an interconnect scheme and procured, installed, and tested the equipment necessary to implement the cell interconnection for thin-film CIGS modules on a polyimide substrate.

  8. Solar cells

    International Nuclear Information System (INIS)

    A method of producing solar cells is described which consists of producing a substantially monocrystalline tubular body of silicon or other suitable semiconductor material, treating this body to form an annular rectifying junction and then cutting it longitudinally to form a number of nearly flat ribbons from which the solar cells are fabricated. The P=N rectifying junction produced by the formation of silicon dioxide on the layers at the inner and outer surfaces of the body can be formed by ion-implantation or diffusion. (U.K.)

  9. Thin film metallic glass as a diffusion barrier for copper indium gallium selenide solar cell on stainless steel substrate: A feasibility study

    Science.gov (United States)

    Diyatmika, Wahyu; Xue, Lingjun; Lin, Tai-Nan; Chang, Chia-wen; Chu, Jinn P.

    2016-08-01

    The feasibility of using Zr53.5Cu29.1Al6.5Ni10.9 thin-film metallic glass (TFMG) as a diffusion barrier for copper indium gallium selenide (CIGS) solar cells on stainless steel (SS) is investigated. The detrimental Fe diffusion from SS into CIGS is found to be effectively hindered by the introduction of a 70-nm-thick TFMG barrier; the cell performance is thus improved. Compared with the 2.73% of CIGS on bare SS, a higher efficiency of 5.25% is obtained for the cell with the Zr52Cu32Al9Ni7 TFMG barrier.

  10. CIG-DB: the database for human or mouse immunoglobulin and T cell receptor genes available for cancer studies

    Directory of Open Access Journals (Sweden)

    Furue Motoki

    2010-07-01

    Full Text Available Abstract Background Immunoglobulin (IG or antibody and the T-cell receptor (TR are pivotal proteins in the immune system of higher organisms. In cancer immunotherapy, the immune responses mediated by tumor-epitope-binding IG or TR play important roles in anticancer effects. Although there are public databases specific for immunological genes, their contents have not been associated with clinical studies. Therefore, we developed an integrated database of IG/TR data reported in cancer studies (the Cancer-related Immunological Gene Database [CIG-DB]. Description This database is designed as a platform to explore public human and murine IG/TR genes sequenced in cancer studies. A total of 38,308 annotation entries for IG/TR proteins were collected from GenBank/DDBJ/EMBL and the Protein Data Bank, and 2,740 non-redundant corresponding MEDLINE references were appended. Next, we filtered the MEDLINE texts by MeSH terms, titles, and abstracts containing keywords related to cancer. After we performed a manual check, we classified the protein entries into two groups: 611 on cancer therapy (Group I and 1,470 on hematological tumors (Group II. Thus, a total of 2,081 cancer-related IG and TR entries were tabularized. To effectively classify future entries, we developed a computational method based on text mining and canonical discriminant analysis by parsing MeSH/title/abstract words. We performed a leave-one-out cross validation for the method, which showed high accuracy rates: 94.6% for IG references and 94.7% for TR references. We also collected 920 epitope sequences bound with IG/TR. The CIG-DB is equipped with search engines for amino acid sequences and MEDLINE references, sequence analysis tools, and a 3D viewer. This database is accessible without charge or registration at http://www.scchr-cigdb.jp/, and the search results are freely downloadable. Conclusions The CIG-DB serves as a bridge between immunological gene data and cancer studies, presenting

  11. Characteristics of Ga-Rich Cu(In, Ga)Se2 Solar Cells Grown on Ga-Doped ZnO Back Contact.

    Science.gov (United States)

    Sun, Qian; Kim, Kyoung-Bo; Jeon, Chan-Wook

    2016-05-01

    Wide bandgap Cu(In,Ga)Se2 (CIGS) thin films were deposited on Ga-rich Ga:ZnO (GZO) or MoN/GZO by single-stage co-evaporation. CIGS/TCO interface phases, such as resistive n-type Ga2O3, which are likely to have formed during the high temperature growth of Ga-rich CIGS, can deteriorate the solar cell performance. Although some Ga accumulation was observed in both of the CIGS/GZO and CIGS/MoN/GZO interfaces formed at 520 degrees C, the Ga oxide layer was absent. On the other hand, their current-voltage characteristics showed strong roll-over behavior regardless of the MoN diffusion barrier. The strong Schottky barrier formation at the CLGS/GZO junction due to the low work function of GZO, was attributed to current blocking at a high forward bias.

  12. Characteristics of Ga-Rich Cu(In, Ga)Se2 Solar Cells Grown on Ga-Doped ZnO Back Contact.

    Science.gov (United States)

    Sun, Qian; Kim, Kyoung-Bo; Jeon, Chan-Wook

    2016-05-01

    Wide bandgap Cu(In,Ga)Se2 (CIGS) thin films were deposited on Ga-rich Ga:ZnO (GZO) or MoN/GZO by single-stage co-evaporation. CIGS/TCO interface phases, such as resistive n-type Ga2O3, which are likely to have formed during the high temperature growth of Ga-rich CIGS, can deteriorate the solar cell performance. Although some Ga accumulation was observed in both of the CIGS/GZO and CIGS/MoN/GZO interfaces formed at 520 degrees C, the Ga oxide layer was absent. On the other hand, their current-voltage characteristics showed strong roll-over behavior regardless of the MoN diffusion barrier. The strong Schottky barrier formation at the CLGS/GZO junction due to the low work function of GZO, was attributed to current blocking at a high forward bias. PMID:27483870

  13. Solar cells

    Science.gov (United States)

    Treble, F. C.

    1980-11-01

    The history, state of the art, and future prospects of solar cells are reviewed. Solar cells are already competitive in a wide range of low-power applications, and during the 1980's they are expected to become cheaper to run than diesel or gasoline generators, the present mainstay of isolated communities. At this stage they will become attractive for water pumping, irrigation, and rural electrification, particularly in developing countries. With further cost reduction, they may be used to augment grid supplies in domestic, commercial, institutional, and industrial premises. Cost reduction to the stage where photovoltaics becomes economic for large-scale power generation in central stations depends on a technological breakthrough in the development of thin-film cells. DOE aims to reach this goal by 1990, so that by the end of the century about 20% of the estimated annual additions to their electrical generating capacity will be photovoltaic.

  14. A simulation study of the effect of the diverse valence-band offset and the electronic activity at the grain boundaries on the performance of polycrystalline Cu(In,Ga)Se{sub 2} solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Nerat, Marko, E-mail: marko.nerat@fe.uni-lj.si; Smole, Franc; Topic, Marko

    2011-08-31

    The paper presents a two-dimensional simulation study of a polycrystalline Cu(In,Ga)Se{sub 2} (CIGS) solar cell with various shapes of grains inside the CIGS absorber layer. The grain boundaries (GBs) with a diverse valence-band offset (VBO) and the density of defect states (N{sub tA}) are considered so as to evaluate their effects on the performance of the CIGS cell. The numerical simulations show that a CIGS cell with column-like grains can achieve a high conversion efficiency ({eta}), while the {eta} of a CIGS cell with diamond-like grains is low if the VBO at the GBs exceeds 0.4 eV. The VBO at which the {eta} of the CIGS cell with diamond-like grains peaks is found at 0.20-0.27 eV. A favorable VBO mainly depends on the shape of the grains, but it also depends on the N{sub tA}. The simulations of the CIGS cells in the substrate and superstrate configurations showed that their performances change if the VBO is varied. This result also implies that the configuration of the CIGS cell is important and the substrate configuration with larger grains in the space-charge region has a considerable advantage if the VBO ranges from 0 eV to 0.2 eV.

  15. Deep absorption band in Cu(In,Ga)Se{sub 2} thin films and solar cells observed by transparent piezoelectric photothermal spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Shirakata, Sho; Atarashi, Akiko [Faculty of Engineering, Ehime University, Matsuyama 790-8577 (Japan); Yagi, Masakazu [Kagawa National College of Technology, Mitoyo-shi 769-1192 (Japan)

    2015-06-15

    The photo-acoustic spectroscopy (PAS) using a transparent piezoelectric photo-thermal (Tr-PPT) method was carried out on Cu(In,Ga)Se{sub 2} (CIGS) thin films (both CIGS/Mo/SLG and CdS/CIGS/Mo/SLG) and solar cells (ZnO/CdS/CIGS/Mo/SLG). Using the Tr-PPT method, the high background absorption in the below gap region observed in both a microphone and a conventional transducer PAS spectra was strongly reduced. This high background absorption came from the CIGS/Mo interface. This result proves that the Tr-PPT PAS is the surface sensitive method. In the below-band region, a bell-shape deep absorption band has been observed at 0.76 eV, in which a full-width at the half-maximum value was 70-120 meV. This deep absorption band was observed for both CdS/CIGS/Mo/SLG and ZnO/CdS/CIGS/Mo/SLG structures. The peak energy of the absorption band was independent of the alloy composition for 0.25≤Ga/III≤0.58. Intensity of the PA signal was negatively correlated to the Na concentration at the CIGS film surface. The origin of the 0.76 eV peak is discussed with relation to native defects such as a Cu-vacancy-related defect (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Estimation of defect activation energy around pn interfaces of Cu(In,Ga)Se2 solar cells using impedance spectroscopy

    Science.gov (United States)

    Sakakura, Hidenori; Itagaki, Masayuki; Sugiyama, Mutsumi

    2016-01-01

    We investigate the defect activation energy around the pn interface of Cu(In,Ga)Se2 (CIGS)-based solar cells using a simple electrochemical impedance spectroscopy. By applying AC and DC voltages to the solar cells, we observed an “inductive” element around the pn interface, which is ignored in conventional deep-level transient spectroscopy or admittance spectroscopy. A defect model is evaluated by proposing an equivalent circuit that includes a positive/negative constant phase element (CPE) to represent the area around the CdS/CIGS interface. By fitting the impedance data, the CPE index and CPE constant show a relationship with the defect activation energy or defect concentration. This result is significant because it may help reveal the defect properties of CIGS solar cells or any other semiconductor devices.

  17. Advantages of using amorphous indium zinc oxide films for window layer in Cu(In,Ga)Se2 solar cells

    International Nuclear Information System (INIS)

    The advantages of using indium zinc oxide (IZO) films instead of conventional Ga-doped zinc oxide (ZnO:Ga) films for Cu(In,Ga)Se2 (CIGS) solar cells are described. The electrical properties of IZO are independent of film thickness. IZO films have higher mobility (30–40 cm2/Vs) and lower resistivity (4–5 × 10−4 Ω cm) compared to ZnO:Ga films deposited without intentional heating, because the number of grain boundaries in amorphous IZO films is small. The properties of a CIGS solar cell using IZO at the window layer were better than those obtained using a conventional ZnO:Ga at the window layer; moreover, the properties tended to be independent of thickness. These results indicate that use of IZO as a transparent conducting oxide layer is expected to increase the efficiency of CIGS solar cells.

  18. Trap-assisted recombination for ohmic-like contact at p-type Cu(In,Ga)Se2/back n-type TCO interface in superstrate-type solar cell

    Science.gov (United States)

    Chantana, Jakapan; Arai, Hiroyuki; Minemoto, Takashi

    2016-07-01

    Cu(In,Ga)Se2 (CIGS) solar cells with superstrate-type structure of soda-lime glass (SLG)/epoxy/Al/ZnO:Al (AZO)/ZnO/CdS/CIGS/back n-type transparent conductive oxide (TCO) electrode/Al are fabricated by lift-off process. AZO or In2O3:Sn (ITO) is used as the back n-type TCO electrode. Ohmic-like contact between p-type CIGS and n-type D-TCO (damage-TCO), namely, D-AZO or D-ITO, is formed through the trap-assisted recombination. The D-TCO, meaning TCO with high sputtering damage on the CIGS surface, is prepared under the optimization of its deposition condition, namely, the power density of 2.4 W/cm2 for D-AZO or 3.3 W/cm2 for D-ITO, for high defect density on the CIGS surface to promote the trap-assisted recombination. Ultimately, the superstrate-type CIGS solar cell with a bi-layer of D-AZO/AZO as back n-type TCO electrode with conversion efficiency (η) of 9.2% is achieved, which is 70% of η of the substrate-type CIGS solar cell before lift-off process. The bi-layer of D-AZO/AZO is utilized owing to high resistivity of D-AZO (about 0.1 Ω cm). On the other hand, the superstrate-type CIGS solar cell with D-ITO as the back n-type TCO electrode with η of 10.4% is attained, which is 93.7% of η of the substrate-type CIGS solar cell, where the resistivity of the D-ITO layer is low at about 5.0 × 10-3 Ω cm.

  19. DEGRADATION OF SOLAR CELLS PARAMETERS FABRICATED ON THE BASIS OF Cu(In,GaSe2 SEMICONDUCTOR SOLID SOLUTIONS UNDER ELECTRON IRRADIATION

    Directory of Open Access Journals (Sweden)

    A. V. Mudryi

    2014-01-01

    Full Text Available Polycrystalline Cu(In,GaSe2 (CIGS thin films were grown on molybdenum-coated soda-lime glass substrates by co-evaporation of the elements Cu, In, Ga and Se from independent sources. The effect of electron irradiation on the electrical and optical properties of CIGS thin films and solar cells with the structure ZnO:Al/i-ZnO/CdS/CIGS/Mo/glass was studied. It was found that the degradation of the electrical parameters of solar cells (open-circuit voltage, short-circuit current density and efficiency took place due to the formation of radiation defects (recombination centers with deep energy levels in the bandgap of CIGS. It was revealed that after electron irradiation intensity of near band-edge luminescence band at about 1,1 eV decreased considerably and bands of luminescence with maxima at 0,93 and 0,75 eV appeared.

  20. Interfacial quality improvement of Cu(In,Ga)Se2 thin film solar cells by Cu-depletion layer formation

    Science.gov (United States)

    Nishimura, Takahito; Toki, Soma; Sugiura, Hiroki; Nakada, Kazuyoshi; Yamada, Akira

    2016-09-01

    Se irradiation with time, t Se, was introduced after the second stage of a three-stage process to control the Cu2Se layer during Cu(In,Ga)Se2 (CIGS) deposition. Open circuit voltage and fill factor of CIGS solar cells could be improved by introducing Se irradiation. We concluded that the control of the Cu2Se layer led to the formation of a Cu-depletion CIGS layer (CDL), which improved conversion efficiency owing to suppression of interfacial recombination by a valence band offset formed between CIGS and the CDL. Finally, highest efficiency of 19.8% was achieved with t Se of 5 min. This very simple and new technique is promising for the improvement of photovoltaic performance.

  1. Characteristics of Cu(In,Ga)Se{sub 2} (CIGS) thin films deposited by a direct solution coating process

    Energy Technology Data Exchange (ETDEWEB)

    Park, Myoung Guk [Photovoltaic Center, Korea Institute of Energy Research, 71-2 JangDong, YuseongGu, DaeJeon 305-343 (Korea, Republic of); Ahn, Se Jin, E-mail: swisstel@kier.re.kr [Photovoltaic Center, Korea Institute of Energy Research, 71-2 JangDong, YuseongGu, DaeJeon 305-343 (Korea, Republic of); Yun, Jae Ho; Gwak, Jihye; Cho, Ara; Ahn, Seoung Kyu; Shin, Keeshik [Photovoltaic Center, Korea Institute of Energy Research, 71-2 JangDong, YuseongGu, DaeJeon 305-343 (Korea, Republic of); Nam, Dahyun; Cheong, Hyeonsik [Department of Physics, Sogang University, Seoul 121-742 (Korea, Republic of); Yoon, Kyunghoon [Photovoltaic Center, Korea Institute of Energy Research, 71-2 JangDong, YuseongGu, DaeJeon 305-343 (Korea, Republic of)

    2012-02-05

    Highlights: Black-Right-Pointing-Pointer Double layered CIGS/carbon films prepared by a direct solution coating. Black-Right-Pointing-Pointer Controllability of compositions of the CIGS layer. Black-Right-Pointing-Pointer Effects of Cu and Ga contents on properties of the CIGS layer. Black-Right-Pointing-Pointer Structure of the bottom carbon layer. - Abstract: Cu(In,Ga)Se{sub 2} (CIGS) thin films were formed by a direct non-vacuum coating and a subsequent selenization of low cost precursor solutions, and their compositional, structural and optical properties were characterized. Selenized films showed a double-layered structure with an upper layer of chalcopyrite CIGS and an amorphous bottom layer mainly composed of carbon. For the upper CIGS layer, good compositional controllability for Cu and Ga was confirmed by linear relationship between metal ratios of the precursor solution and those of the selenized films. Effects of Cu and Ga contents on structural and optical properties of the films were also characterized by X-ray diffraction (XRD), Raman and photoluminescence (PL) analyses, and the results were interpreted by defect supercluster formation (V{sub Cu}-In{sub Cu}) in Cu-deficient films and mass and size difference between In and Ga, respectively. Further, the bottom layer was found to be mostly composed of conductive amorphous carbon, which is the main current flow path in the completed solar cells.

  2. A facile chemical-mechanical polishing lift-off transfer process toward large scale Cu(In,Ga)Se2 thin-film solar cells on arbitrary substrates

    Science.gov (United States)

    Tseng, Kuan-Chun; Yen, Yu-Ting; Thomas, Stuart R.; Tsai, Hung-Wei; Hsu, Cheng-Hung; Tsai, Wen-Chi; Shen, Chang-Hong; Shieh, Jia-Min; Wang, Zhiming M.; Chueh, Yu-Lun

    2016-02-01

    The fabrication of Cu(In,Ga)Se2 (CIGS) solar cells on flexible substrates is a non-trivial task due to thermal and ion diffusion related issues. In order to circumvent these issues, we have developed a chemical-mechanical polishing lift-off (CMPL) transfer process, enabling the direct transfer of CIGS solar cells from conventional soda-lime glass (SLG) onto arbitrary flexible substrates up to 4 cm2 in size. The structural and compositional nature of the pre- and post-transferred films is examined using electron microscopy, X-ray diffraction analysis, Raman and photoluminescence spectroscopy. We demonstrate the fabrication of solar cells on a range of flexible substrates while being able to maintain 75% cell efficiency (η) when compared to pre-transferred solar cells. The results obtained in this work suggest that our transfer process offers a highly promising approach toward large scale fabrication of CIGS-based solar cells on a wide variety of flexible substrates, suitable for use in the large scale CIGS photovoltaic industry.The fabrication of Cu(In,Ga)Se2 (CIGS) solar cells on flexible substrates is a non-trivial task due to thermal and ion diffusion related issues. In order to circumvent these issues, we have developed a chemical-mechanical polishing lift-off (CMPL) transfer process, enabling the direct transfer of CIGS solar cells from conventional soda-lime glass (SLG) onto arbitrary flexible substrates up to 4 cm2 in size. The structural and compositional nature of the pre- and post-transferred films is examined using electron microscopy, X-ray diffraction analysis, Raman and photoluminescence spectroscopy. We demonstrate the fabrication of solar cells on a range of flexible substrates while being able to maintain 75% cell efficiency (η) when compared to pre-transferred solar cells. The results obtained in this work suggest that our transfer process offers a highly promising approach toward large scale fabrication of CIGS-based solar cells on a wide

  3. Flexible Cu(In,Ga)Se2 solar cells fabricated using a polyimide-coated soda-lime glass substrate

    Science.gov (United States)

    Sadono, Adiyudha; Hino, Masashi; Ichikawa, Mitsuru; Yamamoto, Kenji; Kurokawa, Yasuyoshi; Konagai, Makoto; Yamada, Akira

    2015-08-01

    Flexible solar cells with a Cu(In,Ga)Se2 (CIGS) absorber layer were fabricated on a polyimide thin film using a lift-off process. Polyimide-coated soda-lime glass (SLG) was used as a substrate for fabricating CIGS solar cells before the lift-off process conducted to make the cells flexible. A conversion efficiency of 13.4% was achieved by low temperature deposition; this value is comparable to that obtained by direct deposition on a rigid glass substrate even without an external Na source. The final conversion efficiency after the lift-off process was 12.7% with some area correction due to the partial peeling-off between CIGS and Mo. Open-circuit voltage and fill factor did not change before and after the lift-off process, suggesting that the lift-off process did not give any physical damage.

  4. CZTSSe thin film solar cells: Surface treatments

    Science.gov (United States)

    Joglekar, Chinmay Sunil

    Chalcopyrite semiconducting materials, specifically CZTS, are a promising alternative to traditional silicon solar cell technology. Because of the high absorption coefficient; films of the order of 1 micrometer thickness are sufficient for the fabrication of solar cells. Liquid based synthesis methods are advantageous because they are easily scalable using the roll to roll manufacturing techniques. Various treatments are explored in this study to enhance the performance of the selenized CZTS film based solar cells. Thiourea can be used as a sulfur source and can be used to tune band gap of CZTSSe. Bromine etching can be used to manipulate the thickness of sintered CZTSSe film. The etching treatment creates recombination centers which lead to poor device performance. Various after treatments were used to improve the performance of the devices. It was observed that the performance of the solar cell devices could not be improved by any of the after treatment steps. Other surface treatment processes are explored including KCN etching and gaseous H2S treatments. Hybrid solar cells which included use of CIGS nanoparticles at the interface between CZTSSe and CdS are also explored.

  5. Electrodeposition of CuIn1-xGaxSe2 Materials for Solar Cells:

    International Nuclear Information System (INIS)

    This report describes our scientific understanding of the CIGS materials system, solar cells, and processes. Through DOE support, the investigators developed much of the technology and device fabrication infrastructure applied to electrodeposited (ED) materials. The electrodeposition process is simple and fast, and can synthesize multinary precursors for subsequent processing into CuInxGa1-xSe2 (CIGS) thin-film absorbers for solar cells. The device fabricated by using electrodeposited CIGS precursor layers resulted in total-area conversion efficiencies up to 15.4%. As-deposited precursors are Cu-rich CIGS. Additional In, Ga, and Se (up to 50%) are added to the precursor films by physical vapor deposition (PVD) to adjust the final semiconductor film composition to about Cu0.95In0.75Ga0.25Se2. The ED device parameters are compared with those of an 18.8% PVD device. The tools used for comparison are current-voltage, capacitance-voltage, and spectral response characteristics. The individual parameters of the device prepared from ED precursor films showed no significant deterioration from those of the PVD CIGS cells. We also developed a buffer-based electrodeposition bath. Using the buffer solution enhances the stability of the electrodeposition process, and no metal oxides or hydroxides precipitate out of the solution. The buffer-based bath also deposits more gallium in the precursor films. As-deposited precursors are stoichiometric or slightly Cu-rich CIGS. Only a minimal amount (5%-10% of total materials) of indium was added to the ED precursor films by PVD to obtain a 9.4%-efficient device. In general, the films and devices have been characterized by inductively coupled plasma spectrometry, Auger electron spectroscopy, X-ray diffraction, electron-probe microanalysis, current-voltage, capacitance-voltage, and spectral response

  6. Buffer layer selection for CuIn1 − xGa xSe2 based thin film solar cells

    International Nuclear Information System (INIS)

    In this work, device modeling and simulation studies have been carried out with a variety of buffer layers over CIGS absorption layer. The band diagram, electric field variation and I/V curves are analyzed and device performance parameters i.e. efficiency, open circuit voltage, short circuit current, quantum efficiency are calculated. The efficiency of CIGS solar cell with ZnSe buffer layer is found comparable with that of CdS layer. The highest short circuit current is found for solar cell with ZnSe buffer layer, whereas the ZnS/CIGS heterojunction provides the highest quantum efficiency in the structures considered. The device physics is discussed and the effect of thickness of buffer layers and absorption layer is studied in order to find a more efficient and stable solar cell. (papers)

  7. Characteristics of CIGS photovoltaic devices co-evaporated with various Se flux rates at low temperatures

    Science.gov (United States)

    Huang, Chia-Hua; Lin, Chun-Ping; Jan, Yueh-Lin

    2016-08-01

    Cu(In,Ga)Se2 (CIGS) films were prepared by a single-stage co-evaporation process at Se flux rates of 10 Å s-1, 20 Å s-1, and 30 Å s-1 and substrate temperatures ranging from 400 °C to 500 °C. The flux rates of the Cu, In, Ga, and Se were kept constant throughout each deposition of the films. The grain sizes, surface morphologies, and crystallinity of the CIGS films improved with increasing substrate temperatures or Se flux rates. The causes of the formation of voids on the surface of CIGS films deposited with a low Se flux rate of 10 Å s-1 at substrate temperatures of 475 °C and 500 °C were addressed. The higher Se flux rates of 20 Å s-1 and 30 Å s-1 repressed the formation of voids for the CIGS films deposited at the relatively higher substrate temperatures of 475 °C and 500 °C. The conversion efficiencies of CIGS solar cells were significantly improved by increasing the substrate temperatures or the Se flux rates, largely contributed from the enhancement of the open-circuit voltage and fill factor because of the restraint of the carrier recombination. The short-circuit current densities were slightly enhanced by the increment of the substrate temperatures or the Se flux rates, resulting from the improved crystalline quality of the CIGS films. Moreover, the EQE results suggest that the effective carrier-diffusion lengths of the films deposited at the relatively high substrate temperatures were increased, leading to the enhancement of the short-circuit current density. The efficiencies of CIGS solar cells prepared with a Se flux rate of 10 Å s-1 improved from 10% to 12.4% when the substrate temperatures increased from 400 °C to 500 °C. The efficiencies of cells deposited at the substrate temperature of 500 °C improved to 15.4% as the Se flux rates increased from 10 Å s-1 to 30 Å s-1.

  8. Synthesis of Cu-Poor Copper-Indium-Gallium-Diselenide Nanoparticles by Solvothermal Route for Solar Cell Applications

    Directory of Open Access Journals (Sweden)

    Chung Ping Liu

    2014-01-01

    Full Text Available Copper-indium-gallium-diselenide (CIGS thin films were fabricated using precursor nanoparticle ink and sintering technology. The precursor was a Cu-poor quaternary compound with constituent ratios of Cu/(In+Ga=0.603, Ga/(In+Ga=0.674, and Se/(Cu+In+Ga=1.036. Cu-poor CIGS nanoparticles of chalcopyrite for solar cells were successfully synthesized using a relatively simple and convenient elemental solvothermal route. After a fixed reaction time of 36 h at 180°C, CIGS nanocrystals with diameters in the range of 20–70 nm were observed. The nanoparticle ink was fabricated by mixing CIGS nanoparticles, a solvent, and an organic polymer. Analytical results reveal that the Cu-poor CIGS absorption layer prepared from a nanoparticle-ink polymer by sintering has a chalcopyrite structure and a favorable composition. For this kind of sample, its mole ratio of Cu : In : Ga : Se is equal to 0.617 : 0.410 : 0.510 : 2.464 and related ratios of Ga/(In+Ga and Cu/(In+Ga are 0.554 and 0.671, respectively. Under the condition of standard air mass 1.5 global illumination, the conversion efficiency of the solar cell fabricated by this kind of sample is 4.05%.

  9. Encapsulation of Cu(InGa)Se{sub 2} solar cell with Al{sub 2}O{sub 3} thin-film moisture barrier grown by atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Carcia, P.F.; McLean, R.S. [DuPont Research and Development, Experimental Station, Wilmington, DE 19880-0400 (United States); Hegedus, Steven [Institute of Energy Conversion, University of Delaware, Newark, DE 19716-3820 (United States)

    2010-12-15

    We compared the moisture sensitivity of a Cu(InGa)Se{sub 2} (CIGS) photovoltaic cell protected by 55 nm thick Al{sub 2}O{sub 3}, grown by atomic layer deposition (ALD), with equivalent CIGS cells protected with a glass or a polyester lid. Aging studies for more than 1000 h at 85 C/85% relative humidity with simulated solar illumination showed that the ALD Al{sub 2}O{sub 3} thin-film barrier provided superior moisture protection for the CIGS cell, i.e. no reduction in open circuit voltage or fill factor occurred, compared to cells protected with a glass or plastic lid. We concluded that a moisture barrier grown by ALD could have broad applicability as a strategy for extending the lifetime of flexible CIGS cells. (author)

  10. SiO{sub 2} and Al{sub 2}O{sub 3}/SiO{sub 2} coatings for increasing emissivity of Cu(In, Ga)Se{sub 2} thin-film solar cells for space applications

    Energy Technology Data Exchange (ETDEWEB)

    Shimazaki, Kazunori [Japan Aerospace Exploration Agency (JAXA), Institute of Aerospace Technology, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505 (Japan)], E-mail: shimazaki.kazunori@jaxa.jp; Imaizumi, Mitsuru [Japan Aerospace Exploration Agency (JAXA), Institute of Aerospace Technology, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505 (Japan)], E-mail: imaizumi.mitsuru@jaxa.jp; Kibe, Koichi [Japan Aerospace Exploration Agency (JAXA), Institute of Aerospace Technology, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505 (Japan)], E-mail: kibe.koichi@jaxa.jp

    2008-02-29

    In this study, optical coatings were investigated as substitutes for the coverglass on flexible thin-film space solar cells. The inherent low emissivity of copper-indium-gallium-diselenide (CIGS) thin-film solar cells was increased using optical coatings for thermal balance in space. Evaporated silicon dioxide (SiO{sub 2}) and an additional aluminum oxide (Al{sub 2}O{sub 3}) coating on the CIGS solar cell increased the emissivity from 0.18 to 0.77. Higher emissivity was realized with the Al{sub 2}O{sub 3}/SiO{sub 2} double-layer coating than with the SiO{sub 2} single-layer coating. The straightforward double-layer coating gives the CIGS solar cells appropriate radiative properties for keeping the cell within a permissible temperature range in space.

  11. Study the Effect of Annealing Temperature on Optical properties For CIGS Films

    Directory of Open Access Journals (Sweden)

    Harith I. Jaafer

    2015-07-01

    Full Text Available In this research CIGS films were obtained by a drop-coating method and subsequently annealed in nitrogen atmosphere .Optical management is a way to improve the solar cell performance .The optical properties of CIGS films were characterized by UV-vis. Study the optical properties of the deferent concentrations of liquid solutions of CIGS ink, and the absorption still constant from the wavelength range 400 to 600nm ,and then began increase gradually from wavelength range 650nm of all concentrations but it seems more strong absorption of concentration (100 % due to the content of Copper nitrate trihydrate. The transmittance of 50% ,and 100% concentrations is greater than 80 % and reach 100% between wavelength range 400 to 600nm,but it increase in 12%, and 25% concentrations and get up to 100% between wavelength range 350 to 600nm.Thus due to more homogeneity of liquid solutions of CIGS ink. Found that the effect of annealing at 525°C on absorption spectra of all concentrations (12.5, 25, 50, and 100% it’s still height and constant in the wavelength range 380–800 nm and the values of absorbance approximately between 120 to 200%, while the transmittance of all reduced and get the values under 10% of transmittance ,and the increasing of the concentrations at this temperature may be reduce of transmittance.

  12. Modeling solar cells: A method for improving their efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Morales-Acevedo, Arturo, E-mail: amorales@solar.cinvestav.mx [Centro de Investigacion y de Estudios Avanzados del IPN, Electrical Engineering Department, Avenida IPN No. 2508, 07360 Mexico, D.F. (Mexico); Hernandez-Como, Norberto; Casados-Cruz, Gaspar [Centro de Investigacion y de Estudios Avanzados del IPN, Electrical Engineering Department, Avenida IPN No. 2508, 07360 Mexico, D.F. (Mexico)

    2012-09-20

    After a brief discussion on the theoretical basis for simulating solar cells and the available programs for doing this we proceed to discuss two examples that show the importance of doing numerical simulation of solar cells. We shall concentrate in silicon Heterojunction Intrinsic Thin film aSi/cSi (HIT) and CdS/CuInGaSe{sub 2} (CIGS) solar cells. In the first case, we will show that numerical simulation indicates that there is an optimum transparent conducting oxide (TCO) to be used in contact with the p-type aSi:H emitter layer although many experimental researchers might think that the results can be similar without regard of the TCO film used. In this case, it is shown that high work function TCO materials such as ZnO:Al are much better than smaller work function films such as ITO. HIT solar cells made with small work function TCO layers (<4.8 eV) will never be able to reach the high efficiencies already reported experimentally. It will also be discussed that simulations of CIGS solar cells by different groups predict efficiencies around 18-19% or even less, i.e. below the record efficiency reported experimentally (20.3%). In addition, the experimental band-gap which is optimum in this case is around 1.2 eV while several theoretical results predict a higher optimum band-gap (1.4-1.5 eV). This means that there are other effects not included in most of the simulation models developed until today. One of them is the possible presence of an interfacial (inversion) layer between CdS and CIGS. It is shown that this inversion layer might explain the smaller observed optimum band-gap, but some efficiency is lost. It is discussed that another possible explanation for the higher experimental efficiency is the possible variation of Ga concentration in the CIGS film causing a gradual variation of the band-gap. This band-gap grading might help improve the open-circuit voltage and, if it is appropriately done, it can also cause the enhancement of the photo-current density.

  13. Scientific Approach to Renewable Energy Through Solar Cells

    Science.gov (United States)

    Rao, M. C.

    Renewable energy is increasingly viewed as critically important globally. Solar cells convert the energy of the sun into electricity. The method of converting solar energy to electricity is pollution free, and appears a good practical solution to the global energy problems. Energy policies have pushed for different technologies to decrease pollutant emissions and reduce global climate change. Photovoltaic technology, which utilizes sunlight to generate energy, is an attractive alternate energy source because it is renewable, harmless and domestically secure. Transparent conducting metal oxides, being n-type were used extensively in the production of heterojunction cells using p-type Cu2O. The long held consensus is that the best approach to improve cell efficiency in Cu2O-based photovoltaic devices is to achieve both p- and n-type Cu2O and thus p-n homojunction of Cu2O solar cells. Silicon, which, next to oxygen, is the most represented element in the earth's crust, is used for the production of monocrystalline silicon solar cells. Silicon is easily obtained and processed and it is not toxic and does not form compounds that would be environmentally harmful. In contemporary electronic industry silicon is the main semiconducting element. Thin-film cadmium telluride (CdTe) solar cells are the basis of a significant technology with major commercial impact on solar energy production. Polycrystalline thin-film solar cells such as CuInSe2 (CIS), Cu (In, Ga) Se2 (CIGS) and CdTe compound semiconductors are important for terrestrial applications because of their high efficiency, long-term stable performance and potential for low-cost production. Highest record efficiencies of 19.2% for CIGS and 16.5% for CdTe have been achieved.

  14. Hydrazine-Free Solution-Deposited CuIn(S,Se)2 Solar Cells by Spray Deposition of Metal Chalcogenides

    Energy Technology Data Exchange (ETDEWEB)

    Arnou, Panagiota; van Hest, Maikel F. A. M.; Cooper, Carl S.; Malkov, Andrei V.; Walls, John M.; Bowers, Jake W.

    2016-05-18

    Solution processing of semiconductors, such as CuInSe2 and its alloys (CIGS), can significantly reduce the manufacturing costs of thin film solar cells. Despite the recent success of solution deposition approaches for CIGS, toxic reagents such as hydrazine are usually involved, which introduce health and safety concerns. Here, we present a simple and safer methodology for the preparation of high-quality CuIn(S, Se)2 absorbers from metal sulfide solutions in a diamine/dithiol mixture. The solutions are sprayed in air, using a chromatography atomizer, followed by a postdeposition selenization step. Two different selenization methods are explored resulting in power conversion efficiencies of up to 8%.

  15. Impact of secondary barriers on copper-indium-gallium-selenide solar-cell operation

    Science.gov (United States)

    Pudov, Alexei O.

    Thin-film solar cells based on CuInSe2 (CIS) absorber with a band gap of Eg = 1.0 eV and also based on CuIn1-x GaxSe2 (CIGS) alloy absorbers with a band-gap range of Eg = 1.0--1.67 eV are investigated in this work. Intermediate "buffer" semiconductor layers in p-n junctions of CIGS solar cells often improve photodiode properties of the devices. The primary goal of the thesis is to study secondary barriers in the conduction band at the buffer/absorber interface, which may limit current transport and thus reduce the efficiency of the solar cells. The secondary goal is to explore alternative wide-bandgap buffers in CIGS cell structures. CIGS cells with standard CdS buffer layers, and alternative ZnS(O,OH) and InS(O,OH) buffer layers were studied. CdS/CuIn1-xGaxSe2 solar cells with variable Ga content have a range of conduction-band offsets (DeltaEc) in the junction from moderately positive (spike offsets) in CdS/CuInSe2 to moderately negative (cliff offsets) in CdS/CuGaSe 2. Moderate conduction-band spikes in CdS/CIS and low-Ga CdS/CIGS are expected to cause distortions in diode current-voltage (J-V) curves of such solar cells under "red" illumination (hnu < Eg(buffer)); no J-V distortions are expected for high-Ga CdS/CIGS with cliff offsets. These predictions were confirmed in experiments: the distortions were absent for cells with Eg above 1.2--1.3 eV, at which CdS/CIGS DeltaE c is near zero. Experiments and numerical simulations showed that one approach to reduce secondary barriers and J-V distortions in low-Ga high-spike cells is to thin the buffer layer(s). Blue photons (hnu above Eg(buffer)) in the solar spectrum induce photoconductivity in the otherwise compensated buffers, which also results in lowering of the secondary barriers. It was shown that CIGS cells with CdS, InS(O,OH), and ZnS(O,OH) buffers have a similar response to "blue" photons: J-V distortion, if present under red light, is reduced or entirely disappears with blue-light exposure within minutes

  16. Nanostructured Organic Solar Cells

    DEFF Research Database (Denmark)

    Radziwon, Michal Jędrzej; Rubahn, Horst-Günter; Madsen, Morten

    Recent forecasts for alternative energy generation predict emerging importance of supporting state of art photovoltaic solar cells with their organic equivalents. Despite their significantly lower efficiency, number of application niches are suitable for organic solar cells. This work reveals...... the principles of bulk heterojunction organic solar cells fabrication as well as summarises major differences in physics of their operation....

  17. Solar Photovoltaic Cells.

    Science.gov (United States)

    Mickey, Charles D.

    1981-01-01

    Reviews information on solar radiation as an energy source. Discusses these topics: the key photovoltaic material; the bank theory of solids; conductors, semiconductors, and insulators; impurity semiconductors; solid-state photovoltaic cell operation; limitations on solar cell efficiency; silicon solar cells; cadmium sulfide/copper (I) sulfide…

  18. Efficiency enhancement calculations of state-of-the-art solar cells by luminescent layers with spectral shifting, quantum cutting, and quantum tripling function

    NARCIS (Netherlands)

    Ten Kate, O.M.; De Jong, M.; Hintzen, H.T.; Van der Kolk, E.

    2013-01-01

    Solar cells of which the efficiency is not limited by the Shockley-Queisser limit can be obtained by integrating a luminescent spectral conversion layer into the cell structure. We have calculated the maximum efficiency of state-of-the-art c-Si, pc-Si, a-Si, CdTe, GaAs, CIS, CIGS, CGS, GaSb, and Ge

  19. Growth of Zn doped Cu(In, Ga)Se 2 thin films by RF sputtering for solar cell applications

    Science.gov (United States)

    Li, Z. Q.; Liu, Q. Q.; Li, J. J.; Sun, Z.; Chen, Y. W.; Yang, Z.; Huang, S. M.

    2012-02-01

    Cu(In, Ga)Se 2 (CIGS) surface was modified with Zn doping using a magnetron sputtering method. CuInGa:Zn precursor films targeting a CuIn 0.7Ga 0.3Se 2 stoichiometry with increasing Zn content from 0 to 0.8 at% were prepared onto Mo-coated glass substrates via co-sputtering of Cu-Ga alloy, In and Zn targets. The CuInGa:Zn precursors were then selenized with solid Se pellets. The structures and morphologies of grown Zn doped CIGS films were found to depend on the Zn content. At zinc doping level ranging between 0.2 and 0.6 at%, the Zn doping improved the crystallinity and surface morphology of CIGS films. Compared with the performance of the non-doped CIGS cell, the fabricated CIGS solar cell displayed a relative efficiency enhancement of 9-22% and the maximum enhancement was obtained at a Zn content of 0.4 at%.

  20. PEROVSKITE SOLAR CELLS (REVIEW ARTICLE)

    OpenAIRE

    Benli, Deniz Ahmet

    2015-01-01

    A solar cell is a device that converts sunlight into electricity. There are different types of solar cells but this report mainly focuses on a type of new generation solar cell that has the name organo-metal halide perovskite, shortly perovskite solar cells. In this respect, the efficiency of power conversion is taken into account to replace the dominancy of traditional and second generation solar cell fields by perovskite solar cells. Perovskite solar cell is a type of solar cell including a...

  1. 2D - Finite element model of a CIGS module

    Energy Technology Data Exchange (ETDEWEB)

    Janssen, G.J.M.; Slooff, L.H.; Bende, E.E. [ECN Solar Energy, Petten (Netherlands)

    2012-09-15

    The performance of thin-film CIGS modules is often limited due to inhomogeneities in CIGS layers. A 2-dimensional Finite Element Model for CIGS modules is demonstrated that predicts the impact of such inhomogeneities on the module performance. Results are presented of a module with a region of poor diode characteristics. It is concluded that according to this model the effects of poor diodes depend strongly on their location in the module and on their dispersion over the module surface. Due to its generic character the model can also be applied to other series connections of photovoltaic cells.

  2. Non-ionizing energy loss calculations for modeling electron-induced degradation of Cu(In, Ga)Se2 thin-film solar cells

    Science.gov (United States)

    Lu, Ming; Xu, Jing; Huang, Jian-Wei

    2016-09-01

    The lowest energies which make Cu, In, Ga, and Se atoms composing Cu(In, Ga)Se2 (CIGS) material displaced from their lattice sites are evaluated, respectively. The non-ionizing energy loss (NIEL) for electron in CIGS material is calculated analytically using the Mott differential cross section. The relation of the introduction rate (k) of the recombination centers to NIEL is modified, then the values of k at different electron energies are calculated. Degradation modeling of CIGS thin-film solar cells irradiated with various-energy electrons is performed according to the characterization of solar cells and the recombination centers. The validity of the modeling approach is verified by comparison with the experimental data. Project supported by the National Natural Science Foundation of China (Grant No. 11547151).

  3. Degradation of Cu(In, Ga)Se2 thin-film solar cells due to the ionization effect of low-energy electrons

    International Nuclear Information System (INIS)

    Cu (In, Ga)Se2 (CIGS) solar cells were irradiated with 100 keV electrons to reveal the characteristics of created radiation defects. 100 keV electrons cannot produce any displacement defects in CIGS. Low-fluence electrons improve the electrical performance of the CIGS solar cells due to the change in the conductive type of donor to acceptor in a metastable defect, which is equivalent to the light-soaking effect. However, high fluence electrons cause the cell performance to decline. From analysis based on changes in carrier density and electroluminescence, defects causing the decline in performance include donor- and non-radiative types. In addition, red-on-bias experiments showed an increase in IIICu defects due to electron irradiation. Based on these results, the degradation in the electrical performance of the CIGS solar cells irradiated with high electron fluence would be attributable to a change in the conductive type of IIICu defects. - Highlights: • Cu(In,Ga)Se2 Solar cells were irradiated with 100 and 250 keV electrons at low temperature. • These electrons degraded the electrical performance of Cu(In,Ga)Se2 sola cells. • The electrons induced ⅢCu defects in Cu(In,Ga)Se2

  4. Solar cell concentrating system

    International Nuclear Information System (INIS)

    This study reviews fabrication techniques and testing facilities for different solar cells under concentration which have been developed and tested. It is also aimed to examine solar energy concentrators which are prospective candidates for photovoltaic concentrator systems. This may provide an impetus to the scientists working in the area of solar cell technology

  5. ZnS/Zn(O,OH)S-based buffer layer deposition for solar cells

    Science.gov (United States)

    Bhattacharya, Raghu N.

    2009-11-03

    The invention provides CBD ZnS/Zn(O,OH)S and spray deposited ZnS/Zn(O,OH)S buffer layers prepared from a solution of zinc salt, thiourea and ammonium hydroxide dissolved in a non-aqueous/aqueous solvent mixture or in 100% non-aqueous solvent. Non-aqueous solvents useful in the invention include methanol, isopropanol and triethyl-amine. One-step deposition procedures are described for CIS, CIGS and other solar cell devices.

  6. Effect of zinc addition on properties of cadmium sulfide layer and performance of Cu(In,Ga)Se2 solar cell

    International Nuclear Information System (INIS)

    Cd(1−x)ZnxS (CdS:Zn) thin films were grown on an indium tin oxide-coated glass substrate and Cu(In,Ga)Se2 (CIGS) surface by chemical bath deposition for solar cell applications, and their composition, and optical properties were studied to decide the optimum process conditions for buffer layer growth. The average conversion efficiency of CIGS solar panels (24-in.) with the CdS:Zn layer was 0.35% higher than that of conventional solar panels mainly because of the increased open-circuit voltage. This efficiency improvement was not due to modification of the optical properties of the buffer layer, but due to the change in the deposition rate during buffer layer growth. - Highlights: ► CdS:Zn buffer layers were fabricated for Cu(In,Ga)Se2 (CIGS) photovoltaic (PV) panels. ► Composition of buffer layers on indium–tin–oxide (ITO) and CIGS was investigated. ► Transmittance of CdS:Zn on ITO coated glass showed 5% higher than CdS. ► Efficiency of CdS:Zn solution adopted panels showed 0.47% higher than that with CdS. ► However, it was revealed that only Cd and S ions were found at the surface of CIGS

  7. Analysis of heterointerface recombination by Zn{sub 1-x}Mg{sub x}O for window layer of Cu(In,Ga)Se{sub 2} solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Kiyoteru; Minemoto, Takashi; Takakura, Hideyuki [College of Science and Engineering, Ritsumeikan University, 1-1-1, Nojihigashi, Kusatsu, Shiga 525-8577 (Japan)

    2009-04-15

    An adjustment of a conduction band offset (CBO) of a window/absorber heterointerface is important for high efficiency Cu(In,Ga)Se{sub 2} (CIGS) solar cells. In this study, the heterointerface recombination was characterized by the reduction of the thickness of a CdS layer and the adjustment of a CBO value by a Zn{sub 1-x}Mg{sub x}O (ZMO) layer. In ZnO/CdS/CIGS solar cells, open-circuit voltage (V{sub oc}) and shunt resistance (R{sub sh}) decreased with reducing the CdS thickness. In constant, significant reductions of V{sub oc} and R{sub sh} were not observed in ZMO/CdS/CIGS solar cells. With decreasing the CdS thickness, the CBO of (ZnO or ZMO)/CIGS become dominant for recombination. Also, the dominant mechanisms of recombination of the CIGS solar cells are discussed by the estimation of an activation energy obtained from temperature-dependent current-voltage measurements. (author)

  8. Modelling Defects Acceptors And Determination Of Electric Model From The Nyquist Plot And Bode In Thin Film CIGS

    Directory of Open Access Journals (Sweden)

    Demba Diallo

    2015-08-01

    Full Text Available Abstract The performance of the chalcopyrite material CuInGaSe2 CIGS used as an absorber layer in thin-film photovoltaic devices is significantly affected by the presence of native defects. Multivalent defects e.g. double acceptors or simple acceptor are important immaterial used in solar cell production in general and in chalcopyrite materials in particular. We used the thin film solar cell simulation software SCAPS to enable the simulation of multivalent defects with up to five different charge states.Algorithms enabled us to simulate an arbitrary number of possible states of load. The presented solution method avoids numerical inaccuracies caused by the subtraction of two almost equal numbers. This new modelling facility is afterwards used to investigate the consequences of the multivalent character of defects for the simulation of chalcopyrite based CIGS. The capacitance increase with the evolution of the number of defects C- f curves have found to have defect dependence.

  9. Photovoltaic solar cell

    Science.gov (United States)

    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.

  10. Alternative Window Schemes for CuInSe2-Based Solar Cells Final Report: 3 November 1995-December 1997; FINAL

    International Nuclear Information System (INIS)

    This work demonstrated high-efficiency CIGS cells based on highly resistive ZnO buffer layers grown by MOCVD. One cell based on NREL CIGS and a ZnO buffer layer exhibited an active-area efficiency of nearly 14%. This result is one of the best efficiencies reported for a ''direct'' ZnO/CIGS cell made with a vacuum process

  11. Antimony assisted low-temperature processing of CuIn1-xGaxSe2-ySy solar cells

    International Nuclear Information System (INIS)

    Application of the Sb-doping method to low-temperature (≤ 400 oC) processing of CuIn1-xGaxSe2-ySy (CIGS) solar cells is explored, using a hydrazine-based approach to deposit the absorber films. Power conversion efficiencies of 10.5% and 8.4% have been achieved for CIGS devices (0.45 cm2 device area) processed at 400 oC and 360 oC, respectively, with an Sb-incorporation level at 1.2 mol % (relative to the moles of CIGS). Significant Sb-induced grain size enhancement was confirmed for these low processing temperatures using cross-sectional scanning electron microscopy, and an average 2-3% absolute efficiency improvement was achieved in Sb-doped samples compared to their Sb-free sister samples. With Sb inclusion, the CIGS film grain growth temperature is lowered to well below 450 oC, a range compatible with flexible polymer substrate materials such as polyimide. This method opens up access to opportunities in low-temperature processing of CIGS solar cells, an area that is being actively pursued using both traditional vacuum-based as well as other solution-based deposition techniques.

  12. Atmospheric spatial atomic layer deposition of Zn(O,S) buffer layer for Cu(In,Ga)Se2 solar cells

    NARCIS (Netherlands)

    Frijters, C.H.; Poodt, P.; Illeberi, A.

    2016-01-01

    Zinc oxysulfide has been grown by spatial atomic layer deposition (S-ALD) and successfully applied as buffer layer in Cu(In, Ga)Se2 (CIGS) solar cells. S-ALD combines high deposition rates (up to nm/s) with the advantages of conventional ALD, i.e. excellent control of film composition and superior u

  13. Investigation of defect properties in Cu(In,Ga)Se 2 solar cells by deep-level transient spectroscopy

    Science.gov (United States)

    Kerr, L. L.; Li, Sheng S.; Johnston, S. W.; Anderson, T. J.; Crisalle, O. D.; Kim, W. K.; Abushama, J.; Noufi, R. N.

    2004-09-01

    The performance of the chalcopyrite material Cu(In,Ga)Se 2 (CIGS) used as an absorber layer in thin-film photovoltaic devices is significantly affected by the presence of native defects. The deep-level transient spectroscopy (DLTS) technique is used in this work to characterize the defect properties, yielding relevant information about the defect types, their capture cross-sections, and energy levels and densities in the CIGS cells. Three solar cells developed using different absorber growth technologies were analyzed using DLTS, capacitance-voltage ( C- V), and capacitance-temperature ( C- T) techniques. It was found that CIS cells grown at the University of Florida exhibits a middle-gap defect level that may relate to the cell's low fill factor and open-circuit voltage values observed. A high efficiency ( ηc>18%) CIGS cell produced by the National Renewable Energy Laboratory (NREL) was found to contain three minority-carrier (electron) traps and a 13% CIGS cell produced by the Energy Photovoltaics Inc. (EPV) exhibited one majority (hole) trap. The approach followed using the DLTS technique serves as a paradigm for revealing the presence of significant defect levels in absorber materials, and may be used to support the identification of remedial processing operations.

  14. Copper variation in Cu(In,Ga)Se2 solar cells with indium sulphide buffer layer

    International Nuclear Information System (INIS)

    In the manufacturing of Cu(In,Ga)Se2 (CIGS) thin film solar cells the application of a buffer layer on top of the absorber is essential to obtain high efficiency devices. Regarding the roll-to-roll production of CIGS cells and modules a vacuum deposition process for the buffer is preferable to the conventional cadmium sulphide buffer deposited in a chemical bath. Promising results have already been achieved for the deposition of indium sulphide buffer by different vacuum techniques. The solar device performance is very sensitive to the conditions at the absorber-buffer heterojunction. In view of optimization we investigated the influence of the Cu content in the absorber on the current-voltage characteristics. In this work the integral copper content was varied between 19 and 23 at.% in CIGS on glass substrates. An improvement of the cell performance by enhanced open circuit voltage was observed for a reduction to ~ 21 at.% when thermally evaporated indium sulphide was applied as the buffer layer. The influence of stoichiometry deviations on the transport mechanism and secondary barriers in the device was studied using detailed dark and light current-voltage analysis and admittance spectroscopy and compared to the reference CdS-buffered cells. We conclude that the composition of the absorber in the interface region affects current transport in InxSy-buffered and CdS-buffered cells in different ways hence optimal Cu content in those two types of devices is different. - Highlights: • Influence of Cu-variation in CIGS cells with InxSy buffer layer on cell performance • Enhanced efficiency by slight reduction of Cu-content to 21 at.% • Contribution of tunnelling-enhanced interface recombination for higher Cu-content

  15. Progress on Low-Temperature Pulsed Electron Deposition of CuInGaSe2 Solar Cells

    Directory of Open Access Journals (Sweden)

    Massimo Mazzer

    2016-03-01

    Full Text Available The quest for single-stage deposition of CuInGaSe2 (CIGS is an open race to replace very effective but capital intensive thin film solar cell manufacturing processes like multiple-stage coevaporation or sputtering combined with high pressure selenisation treatments. In this paper the most recent achievements of Low Temperature Pulsed Electron Deposition (LTPED, a novel single stage deposition process by which CIGS can be deposited at 250 °C, are presented and discussed. We show that selenium loss during the film deposition is not a problem with LTPED as good crystalline films are formed very close to the melting temperature of selenium. The mechanism of formation of good ohmic contacts between CIGS and Mo in the absence of any MoSe2 transition layers is also illustrated, followed by a brief summary of the measured characteristics of test solar cells grown by LTPED. The 17% efficiency target achieved by lab-scale CIGS devices without bandgap modulation, antireflection coating or K-doping is considered to be a crucial milestone along the path to the industrial scale-up of LTPED. The paper ends with a brief review of the open scientific and technological issues related to the scale-up and the possible future applications of the new technology.

  16. Characteristics of molybdenum bilayer back contacts for Cu(In,Ga)Se{sub 2} solar cells on Ti foils

    Energy Technology Data Exchange (ETDEWEB)

    Roger, Charles, E-mail: charles.rgr@gmail.com [CEA, LITEN, 17 Rue des Martyrs, 38054 Grenoble Cedex 9 (France); Noël, Sébastien; Sicardy, Olivier; Faucherand, Pascal; Grenet, Louis; Karst, Nicolas; Fournier, Hélène; Roux, Frédéric [CEA, LITEN, 17 Rue des Martyrs, 38054 Grenoble Cedex 9 (France); Ducroquet, Frédérique [IMEP-LAHC, Minatec, Grenoble-INP, CNRS UMR 5130, 38016 Grenoble (France); Brioude, Arnaud [Laboratoire des Multimatériaux et Interfaces, UMR 5615, Villeurbanne (France); Perraud, Simon [CEA, LITEN, 17 Rue des Martyrs, 38054 Grenoble Cedex 9 (France)

    2013-12-02

    Molybdenum back contact properties are critical for Cu(In,Ga)Se{sub 2} (CIGS) solar cell performance on metallic substrates. In this work, we investigated the properties of sputter-deposited Mo bilayer back contacts on Ti foils. The morphology, electrical resistivity, optical reflectance and residual mechanical stress of the bottom Mo layer were modified by varying the working pressure during its deposition. Working pressures ranging from 0.27 Pa to 4.00 Pa were used. The top Mo layer was deposited using constant conditions at a pressure of 0.13 Pa. It was demonstrated that unlike a Mo monolayer, the use of a Mo bilayer allows controlling the mechanical stress at the Mo/CIGS interface without degrading the optical reflectance and the electrical resistance of the back contact. It was also found that the morphology of the bottom Mo layer affects the growth of the top Mo layer, resulting in a modified back contact surface morphology. This induces changes in the crystalline orientation of the CIGS layer. The resulting solar cell characteristics strongly vary as a function of the bottom Mo layer deposition pressure. A bottom Mo layer growth at 2.93 Pa allows improving the solar cell conversion efficiency by 1.5 times compared to a bottom Mo layer deposited at 0.27 Pa. Using the improved Mo bilayer back contact, a maximum solar cell efficiency of 10.0% was obtained without sodium addition nor anti-reflection coating. - Highlights: • Mo bilayer back contacts for Cu(In,Ga)Se{sub 2} solar cells were grown on Ti substrates. • The sputtering pressure of the bottom Mo layer was varied between 0.27 Pa and 4 Pa. • The top Mo layer controls the optical and electrical properties of the back contact. • The structure of the bottom Mo layer influences the morphology of the top Mo layer. • The back contact affects the CIGS texture, device series resistance and efficiency.

  17. Efficiently-designed hybrid tandem photovoltaic with organic and inorganic single cells

    Science.gov (United States)

    Vincent, Premkumar; Bae, Jin-Hyuk; Kim, Hyeok

    2016-05-01

    Conjugated polymers for solar-cell applications have been extensively studied and have proven highly beneficial in tandem solar-cell structures. This study focuses on achieving power conversion efficiencies of greater than 10% when in tandem with a highly efficient copper indium gallium diselenide (CIGS) solar cell. The optimal design is suggested based on the result of optical simulations on the organic-CIGS tandem structure. This is one of the first reports to show theoretically an organic-CIGS tandem solar cell to obtain an efficiency of greater than 10%. The best PCE was at a thickness of 200 nm for PTB7:PCBM, the active layer of the organic solar cell, and 400 nm for CIGS active layer. Our best datum showed an efficiency of 11.41% with a short-circuit current density of 11.56 mA/cm2 and a good spectral response at our optimized thicknesses.

  18. Rectenna solar cells

    CERN Document Server

    Moddel, Garret

    2013-01-01

    Rectenna Solar Cells discusses antenna-coupled diode solar cells, an emerging technology that has the potential to provide ultra-high efficiency, low-cost solar energy conversion. This book will provide an overview of solar rectennas, and provide thorough descriptions of the two main components: the diode, and the optical antenna. The editors discuss the science, design, modeling, and manufacturing of the antennas coupled with the diodes. The book will provide concepts to understanding the challenges, fabrication technologies, and materials required to develop rectenna structures. Written by e

  19. In-Situ Probing Plasmonic Energy Transfer in Cu(In, Ga)Se2 Solar Cells by Ultrabroadband Femtosecond Pump-Probe Spectroscopy

    Science.gov (United States)

    Chen, Shih-Chen; Wu, Kaung-Hsiung; Li, Jia-Xing; Yabushita, Atsushi; Tang, Shih-Han; Luo, Chih Wei; Juang, Jenh-Yih; Kuo, Hao-Chung; Chueh, Yu-Lun

    2015-12-01

    In this work, we demonstrated a viable experimental scheme for in-situ probing the effects of Au nanoparticles (NPs) incorporation on plasmonic energy transfer in Cu(In, Ga)Se2 (CIGS) solar cells by elaborately analyzing the lifetimes and zero moment for hot carrier relaxation with ultrabroadband femtosecond pump-probe spectroscopy. The signals of enhanced photobleach (PB) and waned photoinduced absorption (PIA) attributable to surface plasmon resonance (SPR) of Au NPs were in-situ probed in transient differential absorption spectra. The results suggested that substantial carriers can be excited from ground state to lower excitation energy levels, which can reach thermalization much faster with the existence of SPR. Thus, direct electron transfer (DET) could be implemented to enhance the photocurrent of CIGS solar cells. Furthermore, based on the extracted hot carrier lifetimes, it was confirmed that the improved electrical transport might have been resulted primarily from the reduction in the surface recombination of photoinduced carriers through enhanced local electromagnetic field (LEMF). Finally, theoretical calculation for resonant energy transfer (RET)-induced enhancement in the probability of exciting electron-hole pairs was conducted and the results agreed well with the enhanced PB peak of transient differential absorption in plasmonic CIGS film. These results indicate that plasmonic energy transfer is a viable approach to boost high-efficiency CIGS solar cells.

  20. Behavior of Photocarriers in the Light-Induced Metastable State in the p-n Heterojunction of a Cu(In,Ga)Se2 Solar Cell with CBD-ZnS Buffer Layer.

    Science.gov (United States)

    Lee, Woo-Jung; Yu, Hye-Jung; Wi, Jae-Hyung; Cho, Dae-Hyung; Han, Won Seok; Yoo, Jisu; Yi, Yeonjin; Song, Jung-Hoon; Chung, Yong-Duck

    2016-08-31

    We fabricated Cu(In,Ga)Se2 (CIGS) solar cells with a chemical bath deposition (CBD)-ZnS buffer layer grown with varying ammonia concentrations in aqueous solution. The solar cell performance was degraded with increasing ammonia concentration, due to actively dissolved Zn atoms during CBD-ZnS precipitation. These formed interfacial defect states, such as hydroxide species in the CBD-ZnS film, and interstitial and antisite Zn defects at the p-n heterojunction. After light/UV soaking, the CIGS solar cell performance drastically improved, with a rise in fill factor. With the Zn-based buffer layer, the light soaking treatment containing blue photons induced a metastable state and enhanced the CIGS solar cell performance. To interpret this effect, we suggest a band structure model of the p-n heterojunction to explain the flow of photocarriers under white light at the initial state, and then after light/UV soaking. The determining factor is a p+ defect layer, containing an amount of deep acceptor traps, located near the CIGS surface. The p+ defect layer easily captures photoexcited electrons, and then when it becomes quasi-neutral, attracts photoexcited holes. This alters the barrier height and controls the photocurrent at the p-n junction, and fill factor values, determining the solar cell performance.

  1. Quantum dot solar cells

    CERN Document Server

    Wu, Jiang

    2013-01-01

    The third generation of solar cells includes those based on semiconductor quantum dots. This sophisticated technology applies nanotechnology and quantum mechanics theory to enhance the performance of ordinary solar cells. Although a practical application of quantum dot solar cells has yet to be achieved, a large number of theoretical calculations and experimental studies have confirmed the potential for meeting the requirement for ultra-high conversion efficiency. In this book, high-profile scientists have contributed tutorial chapters that outline the methods used in and the results of variou

  2. Dye Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Di Wei

    2010-03-01

    Full Text Available Dye sensitized solar cell (DSSC is the only solar cell that can offer both the flexibility and transparency. Its efficiency is comparable to amorphous silicon solar cells but with a much lower cost. This review not only covers the fundamentals of DSSC but also the related cutting-edge research and its development for industrial applications. Most recent research topics on DSSC, for example, applications of nanostructured TiO2, ZnO electrodes, ionic liquid electrolytes, carbon nanotubes, graphene and solid state DSSC have all been included and discussed.

  3. Solar cell radiation handbook

    Science.gov (United States)

    Tada, H. Y.; Carter, J. R., Jr.; Anspaugh, B. E.; Downing, R. G.

    1982-01-01

    The handbook to predict the degradation of solar cell electrical performance in any given space radiation environment is presented. Solar cell theory, cell manufacturing and how they are modeled mathematically are described. The interaction of energetic charged particles radiation with solar cells is discussed and the concept of 1 MeV equivalent electron fluence is introduced. The space radiation environment is described and methods of calculating equivalent fluences for the space environment are developed. A computer program was written to perform the equivalent fluence calculations and a FORTRAN listing of the program is included. Data detailing the degradation of solar cell electrical parameters as a function of 1 MeV electron fluence are presented.

  4. Photovoltaic solar cell

    Energy Technology Data Exchange (ETDEWEB)

    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.

  5. Photovoltaic solar cell

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. Investigation of sputtered Mo layers on soda-lime glass substrates for CIGS solar cells

    International Nuclear Information System (INIS)

    The influences of deposition parameters on the structural, electrical and mechanical properties of the molybdenum films deposited on the soda-lime glass substrates by dc magnetron sputtering were investigated. The results revealed that there was a significant impact of working pressure on the properties of as-deposited Mo films. The surface morphology of films varied from dense to porous microstructure as working pressure was increased. Under low working pressure, the films possessed low resistivity but poor adhesion. In contrast, the films deposited at high working pressure exhibited good adhesion but high resistivity. Moreover, the high sputtering power and the low sputtering voltage reduced the resistivity and enhanced the adhesion of Mo films, respectively. In order to improve the resistivity and adhesion of Mo films, a bi-layer structure deposited under different conditions was studied. Under the given deposition conditions, both low resistivity of 9.71 µΩ cm and good adhesion have been achieved for the Mo films with a bi-layer structure. (paper)

  7. Thinning of CIGS solar cells: Part I: Chemical processing in acidic bromine solutions

    Energy Technology Data Exchange (ETDEWEB)

    Bouttemy, M.; Tran-Van, P. [Institut Lavoisier de Versailles (ILV-UMR 8180 CNRS/UVSQ), 45 av. des Etats Unis, 78035 Versailles (France); Gerard, I., E-mail: gerard@chimie.uvsq.fr [Institut Lavoisier de Versailles (ILV-UMR 8180 CNRS/UVSQ), 45 av. des Etats Unis, 78035 Versailles (France); Hildebrandt, T.; Causier, A. [Institut Lavoisier de Versailles (ILV-UMR 8180 CNRS/UVSQ), 45 av. des Etats Unis, 78035 Versailles (France); Pelouard, J.L.; Dagher, G. [Laboratoire de Photonique et de Nanostructures (LPN-CNRS), route de Nozay 91460 Marcoussis (France); Jehl, Z.; Naghavi, N. [Institut de Recherche et Developpement sur l' Energie Photovoltaique (IRDEP -UMR 7174 CNRS/EDF/Chimie-ParisTech), 6 quai Watier, 78401 Chatou (France); Voorwinden, G.; Dimmler, B. [Wuerth Elektronik Research GmbH, Industriestr. 4, 70565 Stuttgart (Germany); Powalla, M. [Zentrum fuer Sonnenenergie- und Wasserstoff-Forschung (ZSW), Industriestr. 6, 70565 Stuttgart (Germany); Guillemoles, J.F. [Institut de Recherche et Developpement sur l' Energie Photovoltaique (IRDEP -UMR 7174 CNRS/EDF/Chimie-ParisTech), 6 quai Watier, 78401 Chatou (France); Lincot, D. [Laboratoire de Photonique et de Nanostructures (LPN-CNRS), route de Nozay 91460 Marcoussis (France); Etcheberry, A. [Institut Lavoisier de Versailles (ILV-UMR 8180 CNRS/UVSQ), 45 av. des Etats Unis, 78035 Versailles (France)

    2011-08-31

    CIGSe absorber was etched in HBr/Br{sub 2}/H{sub 2}O to prepare defined thicknesses of CIGSe between 2.7 and 0.5 {mu}m. We established a reproducible method of reducing the absorber thickness via chemical etching. We determine the dissolution kinetics rate of CIGSe using trace analysis by graphite furnace atomic absorption spectrometry of Ga and Cu. The roughness of the etching surface decreases during the first 500 nm of the etching to a steady state value of the root-mean-square roughness near 50 nm. X-ray photoelectron spectroscopy analyses demonstrate an etching process occurring with a constant chemical composition of the treated surface acidic bromine solutions provide a controlled chemical thinning process resulting in an almost flat surface and a very low superficial Se{sup 0} enrichment.

  8. Manufacturing technology development for CuInGaSe2 solar cell modules

    Science.gov (United States)

    Stanbery, B. J.

    1991-11-01

    The report describes research performed by Boeing Aerospace and Electronics under the Photovoltaic Manufacturing Technology project. We anticipate that implementing advanced semiconductor device fabrication techniques to the production of large area CuIn(1-x)Ga(x)Se2 (CIGS)/Cd(1-y)Zn(y)S/ZnO monolithically integrated thin film solar cell modules will enable 15 pct. median efficiencies to be achieved in high volume manufacturing. We do not believe that CuInSe2 (CIS) can achieve this efficiency in production without sufficient gallium to significantly increase the band gap, thereby matching it better to the solar spectrum (i.e., x greater than or = 0.2). Competing techniques for CIS film formation have not been successfully extended to CIGS devices with such high band gaps. The SERI-confirmed intrinsic stability of CIS-based photovoltaics renders them far superior to a-Si:H-based devices, making a 30 year module lifetime feasible. The minimal amounts of cadmium used in the structure we propose, compared to CdTe-based devices, makes them environmentally safer and more acceptable to both consumers and relevant regulatory agencies. Large area integrated thin film CIGS modules are the product most likely to supplant silicon modules by the end of this decade and enable the cost improvements which will lead to rapid market expansion.

  9. Manufacturing technology development for CuInGaSe sub 2 solar cell modules

    Energy Technology Data Exchange (ETDEWEB)

    Stanbery, B.J. (Boeing Aerospace and Electronics Co., Seattle, WA (United States))

    1991-11-01

    The report describes research performed by Boeing Aerospace and Electronics under the Photovoltaic Manufacturing Technology project. We anticipate that implementing advanced semiconductor device fabrication techniques to the production of large-area CuIn{sub 1-x}Ga{sub x}Se{sub 2} (CIGS)/Cd{sub 1-y}Zn{sub y}S/ZnO monolithically integrated thin-film solar cell modules will enable 15% median efficiencies to be achieved in high-volume manufacturing. We do not believe that CuInSe{sub 2} (CIS) can achieve this efficiency in production without sufficient gallium to significantly increase the band gap, thereby matching it better to the solar spectrum (i.e., x{ge}0.2). Competing techniques for CIS film formation have not been successfully extended to CIGS devices with such high band gaps. The SERI-confirmed intrinsic stability of CIS-based photovoltaics renders them far superior to a-Si:H-based devices, making a 30-year module lifetime feasible. The minimal amounts of cadmium used in the structure we propose, compared to CdTe-based devices, makes them environmentally safer and more acceptable to both consumers and relevant regulatory agencies. Large-area integrated thin-film CIGS modules are the product most likely to supplant silicon modules by the end of this decade and enable the cost improvements which will lead to rapid market expansion.

  10. Structure and properties of CIGS films based on one-stage RF-sputtering process at low substrate temperature

    Institute of Scientific and Technical Information of China (English)

    Yong Yan; Shasha Li; Yufeng Ou; Yaxin Ji; Chuanpeng Yan; Lian Liu; Zhou Yu; Yong Zhao

    2014-01-01

    Currently, Nanjing South Railway Station planning to implement slate roof renovation is integrating solar cell modules into traditional roof materials to gen-erate clean energy. Copper-indium-gallium diselenide (CuIn1-xGaxSe2, CIGS) is one of the most promising materials for thin film solar cells. Cu(In1-xGax)Se2 films were deposited by a one-step radio frequency magnetron sputtering process at low substrate temperature. X-ray diffraction, Raman, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and electrical and optical measurements were carried out to investigate the deposited films. The results reveal that a temperature of 320 ?C is critical for near-stoichiometric CIGS films with uniform surface morphology. Cu-rich phase particulates are found at less than this temperature. The sample deposited at 380 ?C gives well-crystalline single-phase CIGS film. Furthermore, the electrical and optical performances of the absorber layer are improved significantly with the increasing substrate temperature.

  11. Nanocrystal Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    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.

  12. Identification and Analysis of Distinct Features in Imaging Thin-Film Solar Cells: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Zaunbrecher, K. N.; Johnston, S. W.; Sites, J. R.

    2012-06-01

    Electroluminescence and photoluminescence (EL and PL) are two imaging techniques employed at NREL that are used to qualitatively evaluate solar cells. In this work, imaging lab-scale CdTe and CIGS devices provides information about small-area PV response, which will aid in determining the effects of non-uniformities on cell performance. EL, PL, and dark lock-in thermography signatures are first catalogued. Their responses to varying conditions are then studied. Further analysis includes acquiring spectral data, making microscopy measurements, and correlating luminescence to device performance. The goal of this work is to quantitatively determine non-uniformity effects on cell performance using rapid imaging techniques.

  13. Nanostructured Semiconductor Device Design in Solar Cells

    Science.gov (United States)

    Dang, Hongmei

    We demonstrate the use of embedded CdS nanowires in improving spectral transmission loss and the low mechanical and electrical robustness of planar CdS window layer and thus enhancing the quantum efficiency and the reliability of the CdS-CdTe solar cells. CdS nanowire window layer enables light transmission gain at 300nm-550nm. A nearly ideal spectral response of quantum efficiency at a wide spectrum range provides an evidence for improving light transmission in the window layer and enhancing absorption and carrier generation in absorber. Nanowire CdS/CdTe solar cells with Cu/graphite/silver paste as back contacts, on SnO2/ITO-soda lime glass substrates, yield the highest efficiency of 12% in nanostructured CdS-CdTe solar cells. Reliability is improved by approximately 3 times over the cells with the traditional planar CdS counterpart. Junction transport mechanisms are delineated for advancing the basic understanding of device physics at the interface. Our results prove the efficacy of this nanowire approach for enhancing the quantum efficiency and the reliability in windowabsorber type solar cells (CdS-CdTe, CdS-CIGS and CdS-CZTSSe etc) and other optoelectronic devices. We further introduce MoO3-x as a transparent, low barrier back contact. We design nanowire CdS-CdTe solar cells on flexible foils of metals in a superstrate device structure, which makes low-cost roll-to-roll manufacturing process feasible and greatly reduces the complexity of fabrication. The MoO3 layer reduces the valence band offset relative to the CdTe, and creates improved cell performance. Annealing as-deposited MoO3 in N 2 reduces series resistance from 9.98 O/cm2 to 7.72 O/cm2, and hence efficiency of the nanowire solar cell is improved from 9.9% to 11%, which efficiency comparable to efficiency of planar counterparts. When the nanowire solar cell is illuminated from MoO 3-x /Au side, it yields an efficiency of 8.7%. This reduction in efficiency is attributed to decrease in Jsc from 25.5m

  14. Investigations into alterntive substrate, absorber, and buffer layer processing for Cu(In,Ga)Se{sub 2}-based solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Tuttle, J.R.; Berens, T.A.; Keane, J. [National Renewable Energy Lab., Golden, CO (United States)] [and others

    1996-05-01

    High-performance Cu(In,Ga)Se{sub 2}(CIGS)-based solar cells are presently fabricated within a narrow range of processing options. In this contribution, alternative substrate, absorber, and buffer layer processing is considered. Cell performance varies considerably when alternative substrates are employed. These variations are narrowed with the addition of Na via a Na{sub 2}S compound. Sputtered and electrodeposited CIGS precursors and completed absorbers show promise as alternatives to evaporation. A recrystallization process is required to improve their quality. (In,Ga){sub y}Se buffer layers contribute to cell performance above 10. Further improvements in these alternatives will lead to combined cell performance greater than 10% in the near term.

  15. Welded solar cell interconnection

    Science.gov (United States)

    Stofel, E. J.; Browne, E. R.; Meese, R. A.; Vendura, G. J.

    1982-01-01

    The efficiency of the welding of solar-cell interconnects is compared with the efficiency of soldering such interconnects, and the cases in which welding may be superior are examined. Emphasis is placed on ultrasonic welding; attention is given to the solar-cell welding machine, the application of the welding process to different solar-cell configurations, producibility, and long-life performance of welded interconnects. Much of the present work has been directed toward providing increased confidence in the reliability of welding using conditions approximating those that would occur with large-scale array production. It is concluded that there is as yet insufficient data to determine which of three methods (soldering, parallel gap welding, and ultrasonic welding) provides the longest-duration solar panel life.

  16. Parameterization of solar cells

    Science.gov (United States)

    Appelbaum, J.; Chait, A.; Thompson, D.

    1992-10-01

    The aggregation (sorting) of the individual solar cells into an array is commonly based on a single operating point on the current-voltage (I-V) characteristic curve. An alternative approach for cell performance prediction and cell screening is provided by modeling the cell using an equivalent electrical circuit, in which the parameters involved are related to the physical phenomena in the device. These analytical models may be represented by a double exponential I-V characteristic with seven parameters, by a double exponential model with five parameters, or by a single exponential equation with four or five parameters. In this article we address issues concerning methodologies for the determination of solar cell parameters based on measured data points of the I-V characteristic, and introduce a procedure for screening of solar cells for arrays. We show that common curve fitting techniques, e.g., least squares, may produce many combinations of parameter values while maintaining a good fit between the fitted and measured I-V characteristics of the cell. Therefore, techniques relying on curve fitting criteria alone cannot be directly used for cell parameterization. We propose a consistent procedure which takes into account the entire set of parameter values for a batch of cells. This procedure is based on a definition of a mean cell representing the batch, and takes into account the relative contribution of each parameter to the overall goodness of fit. The procedure is demonstrated on a batch of 50 silicon cells for Space Station Freedom.

  17. Copper variation in Cu(In,Ga)Se{sub 2} solar cells with indium sulphide buffer layer

    Energy Technology Data Exchange (ETDEWEB)

    Spiering, S., E-mail: stefanie.spiering@zsw-bw.de [Zentrum für Sonnenenergie- und Wasserstoff-Forschung (ZSW) Baden-Wuerttemberg, Industriestrasse 6, 70565 Stuttgart (Germany); Paetel, S.; Kessler, F. [Zentrum für Sonnenenergie- und Wasserstoff-Forschung (ZSW) Baden-Wuerttemberg, Industriestrasse 6, 70565 Stuttgart (Germany); Igalson, M.; Abdel Maksoud, H. [Warsaw University of Technology (WUT), Faculty of Physics, Koszykowa 75, 00-662 Warszawa (Poland)

    2015-05-01

    In the manufacturing of Cu(In,Ga)Se{sub 2} (CIGS) thin film solar cells the application of a buffer layer on top of the absorber is essential to obtain high efficiency devices. Regarding the roll-to-roll production of CIGS cells and modules a vacuum deposition process for the buffer is preferable to the conventional cadmium sulphide buffer deposited in a chemical bath. Promising results have already been achieved for the deposition of indium sulphide buffer by different vacuum techniques. The solar device performance is very sensitive to the conditions at the absorber-buffer heterojunction. In view of optimization we investigated the influence of the Cu content in the absorber on the current-voltage characteristics. In this work the integral copper content was varied between 19 and 23 at.% in CIGS on glass substrates. An improvement of the cell performance by enhanced open circuit voltage was observed for a reduction to ~ 21 at.% when thermally evaporated indium sulphide was applied as the buffer layer. The influence of stoichiometry deviations on the transport mechanism and secondary barriers in the device was studied using detailed dark and light current-voltage analysis and admittance spectroscopy and compared to the reference CdS-buffered cells. We conclude that the composition of the absorber in the interface region affects current transport in In{sub x}S{sub y}-buffered and CdS-buffered cells in different ways hence optimal Cu content in those two types of devices is different. - Highlights: • Influence of Cu-variation in CIGS cells with In{sub x}S{sub y} buffer layer on cell performance • Enhanced efficiency by slight reduction of Cu-content to 21 at.% • Contribution of tunnelling-enhanced interface recombination for higher Cu-content.

  18. Cu(In,Ga)Se{sub 2} solar cells with double layered buffers grown by chemical bath deposition

    Energy Technology Data Exchange (ETDEWEB)

    Li, Z.Q.; Shi, J.H.; Zhang, D.W.; Liu, Q.Q.; Sun, Z.; Chen, Y.W. [Engineering Research Center for Nanophotonics and Advanced Instrument, Ministry of Education, Department of Physics, East China Normal University, North Zhongshan Rd. 3663, Shanghai 200062 (China); Yang, Z. [Key Laboratory for Thin Film and Microfabrication of the Ministry of Education, Research Institute of Micro/Nano Science and Technology, Shanghai Jiao Tong University, Shanghai 200240 (China); Huang, S.M., E-mail: engp5591@yahoo.com [Engineering Research Center for Nanophotonics and Advanced Instrument, Ministry of Education, Department of Physics, East China Normal University, North Zhongshan Rd. 3663, Shanghai 200062 (China)

    2011-10-31

    In based mixture In{sub x}(OH,S){sub y} buffer layers deposited by chemical bath deposition technique are a viable alternative to the traditional cadmium sulfide buffer layer in thin film solar cells. We report on the results of manipulating the absorber/buffer interface between the chalcopyrite Cu(In,Ga)Se{sub 2} (CIGS) absorber and CdS or ZnS buffer by addition of a thin In based mixture layer. It is shown that the presence of thin In{sub x}(OH,S){sub y} at the CIGS absorber/CdS or ZnS buffer interfaces greatly improve the solar cell performances. The performances of CIGS cells using dual buffer layers composed of In{sub x}(OH,S){sub y}/CdS or In{sub x}(OH,S){sub y}/ZnS increased by 22.4% and 51.6%, as compared to the single and standard CdS or ZnS buffered cells, respectively.

  19. Fabricating Cu(In,Ga)Se2 solar cells on flexible substrates by a new roll-to-roll deposition system suitable for industrial applications

    International Nuclear Information System (INIS)

    In this work, a new hybrid sputtering–evaporation system providing a scalable process for deposition of Cu(In,Ga)Se2 (CIGS) layers is presented. The growth apparatus has been designed and realized to fit a size suitable for direct industrial transfer. In this process the metal precursors are first of all sputtered on rotating transfer devices, then evaporated on the substrate by local heating in a Se atmosphere. The desired thickness and composition of the CIGS film are obtained by repeated sputtering–evaporation cycles. The cylindrical geometry of the deposition chamber has been designed to accommodate different types of flexible substrates with a maximum size of 20 × 120 cm2 in a roll-to-roll configuration. Several techniques, including secondary ion mass spectrometry, Raman and photoluminescence spectroscopies, x-ray diffraction, scanning electron microscopy, external quantum efficiency, and I–V under 1 Sun illumination, have been used to test both the as-grown CIGS layers and the solar cell devices based on them. A significant performance and good control of Ga grading and Na content were obtained for solar cells grown at 450 °C on polyimide substrates with high deposition rates. In spite of the fact that the present efficiency record for CIGS solar cells on polyimide substrates is 20.4%, the 10.1% obtained using the hybrid method presented in this work is significant because the growth apparatus meets the requirements for direct industrial transfer. In fact, this process is being transferred in a 1 MW production line, where standard CIGS layers are deposited at low temperature on flexible substrates in a single-step process with a 1 mm sec−1 substrate velocity. (paper)

  20. Solar cell element

    Energy Technology Data Exchange (ETDEWEB)

    Nakano, Akihiko; Matsumoto, Hitoshi; Uda, Hiroshi; Komatsu, Yasumitsu; Ikegami, Kiyoharu.

    1989-05-18

    In the existing CdS/CdTe-based solar cell element, nothing is formed except the component effective for generating electromotive force and the components necessary for leading, collecting and extracting the generated electricity, hence even when the element shows deterioration of its performance during its usage, it has been difficult to analyze the above situation. In addition, it has also a defect that its characteristic such as the transfer efficiency in the neighborhood of its glass substrate in connection also with its manufacturing process. In order to solve the above problematical points, this invention proposes, with regard to a CdS-based solar cell element composed by forming a thin film on its substrate, to make a blank space on the above substrate and form thereon a thin film which composes the solar cell element concerned alone or in a piling up manner. 4 figs.

  1. Optoelectronics of solar cells

    CERN Document Server

    Smestad, Greg P

    2002-01-01

    With concerns about worldwide environmental security, global warming, and climate change due to emissions of carbon dioxide from the burning of fossil fuels, it is desirable to have a wide range of energy technologies in a nation's portfolio. Photovoltaics, or solar cells, are a viable option as a nonpolluting renewable energy source. This text is designed to be an overview of photovoltaic solar cells for those in the fields of optics and optical engineering, as well as those who are interested in energy policy, economics, and the requirements for efficient photo-to-electric energy conversion.

  2. Characterization of solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Haerkoenen, J.; Tuominen, E.; Nybergh, K.; Ezer, Y.; Yli-Koski, M.; Sinkkonen, J. [Helsinki Univ. of Technology, Otaniemi (Finland). Dept. of Electrical and Communications Engineering

    1998-10-01

    Photovoltaic research in the Electron Physics Laboratory started in 1993, when laboratory joined the national TEKES/NEMO 2 research program. Since the beginning of the project, characterization as well as experimentally orientated development of the fabrication process of the solar cells were carried out parallery. The process development research started by the initiatives of the Finnish industry. At the moment a large amount of the laboratory personnel works on solar cell research and the financing comes mainly from external projects. The funding for the research has come from TEKES, Ministry of Education, Finnish Academy, GETA graduate school, special equipment grants of the university, and from the laboratory

  3. Investigation of CdZnS Buffer Layers on the Performance of CuInGaSe2 and CuGaSe2 Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Song, J.; Li, S. S.; Chen, L.; Noufi, R.; Anderson, T. J.; Crisalle, O. D.

    2006-01-01

    Cu(In,Ga)Se{sub 2} (CIGS) and CuGaSe{sub 2} (CGS) solar cells were fabricated using Cd{sub 1-x}Zn{sub x}S (CdZnS) buffer layers prepared by chemical bath deposition (CBD) with relative Zn compositions in the CBD bath values of X{sub bath} = 0 (i.e., pure CdS), 0.1, 0.2, 0.3, 0.4, and 0.5. The cell performance parameters of CIGS and CGS films treated with a KCN solution were investigated and compared to cells without KCN treatment. It was found that absorber films treated with KCN etching prior to the buffer CBD step show an improved cell performance for both the CIGS and CGS cells deposited with either CdS or CdZnS buffer layer. A CIGS cell with CdZnS buffer layer of X{sub bath} = 0.2 produced a 13% AM1.5G conversion efficiency with higher V{sub oc}, J{sub sc}, and FF values as compared to the CdZnS/CIGS cells with different Zn contents. Results of photo- J-V and quantum efficiency (QE) measurements reveal that the CGS cell with CdZnS buffer layer of X{sub bath} = 0.3 performed better than the CGS cell deposited with a pure CdS buffer layer. This result is suggested as a result of an increased photocurrent at shorter wavelengths and a more favorable conduction band-offset at the CdZnS/CGS junction.

  4. Advanced Processing of CdTe- and CuIn{sub x}Ga{sub 1{minus}x}Se{sub 2}-Based Solar Cells; Phase I Report

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-09-05

    The main tasks of the cadmium telluride portion of this project include the development of simplified processing for fabricating high-efficiency CdTe solar cells, studies on the long-term stability of CdTe devices, and the development of alternative transparent conducting oxides, window layers, and back contacts. The second portion of this project focused on CIGS solar cells. The main tasks include the development of a manufacturable process for CIGS devices and the development of high-band-gap alloys for use in tandem cell structures. Additional objectives include development of improved junction formation processing and contributing to the overall understanding of these materials and devices. Because the processing is manufacturing-driven, the authors use an all solid-state, simplified two-step process that relaxes the level of deposition control required.

  5. NASA Facts, Solar Cells.

    Science.gov (United States)

    National Aeronautics and Space Administration, Washington, DC.

    The design and function of solar cells as a source of electrical power for unmanned space vehicles is described in this pamphlet written for high school physical science students. The pamphlet is one of the NASA Facts Science Series (each of which consists of four pages) and is designed to fit in the standard size three-ring notebook. Review…

  6. Improved efficiency of a large-area Cu(In,Ga)Se₂ solar cell by a nontoxic hydrogen-assisted solid Se vapor selenization process.

    Science.gov (United States)

    Wu, Tsung-Ta; Hu, Fan; Huang, Jyun-Hong; Chang, Chia-ho; Lai, Chih-chung; Yen, Yu-Ting; Huang, Hou-Ying; Hong, Hwen-Fen; Wang, Zhiming M; Shen, Chang-Hong; Shieh, Jia-Min; Chueh, Yu-Lun

    2014-04-01

    A nontoxic hydrogen-assisted solid Se vapor selenization process (HASVS) technique to achieve a large-area (40 × 30 cm(2)) Cu(In,Ga)Se2 (CIGS) solar panel with enhanced efficiencies from 7.1 to 10.8% (12.0% for active area) was demonstrated. The remarkable improvement of efficiency and fill factor comes from improved open circuit voltage (Voc) and reduced dark current due to (1) decreased interface recombination raised from the formation of a widened buried homojunction with n-type Cd(Cu) participation and (2) enhanced separation of electron and hole carriers resulting from the accumulation of Na atoms on the surface of the CIGS film. The effects of microstructural, compositional, and electrical characteristics with hydrogen-assisted Se vapor selenization, including interdiffusion of atoms and formation of buried homojunction, were examined in detail. This methodology can be also applied to CIS (CuInSe2) thin film solar cells with enhanced efficiencies from 5.3% to 8.5% (9.4% for active area) and provides a facile approach to improve quality of CIGS and stimulate the nontoxic progress in the large scale CIGS PV industry.

  7. Interaction of ultra-short laser pulses with CIGS and CZTSe thin films

    Science.gov (United States)

    Gečys, P.; Markauskas, E.; Dudutis, J.; Račiukaitis, G.

    2014-01-01

    The thin-film solar cell technologies based on complex quaternary chalcopyrite and kesterite materials are becoming more attractive due to their potential for low production costs and optimal spectral performance. As in all thin-film technologies, high efficiency of small cells might be maintained with the transition to larger areas when small segments are interconnected in series to reduce photocurrent and related ohmic losses in thin films. Interconnect formation is based on the three scribing steps, and the use of a laser is here crucial for performance of the device. We present our simulation and experimental results on the ablation process investigations in complex CuIn1- x Ga x Se2 (CIGS) and Cu2ZnSn(S,Se)4 (CZTSe) cell's films using ultra-short pulsed infrared (~1 μm) lasers which can be applied to the damage-free front-side scribing processes. Two types of processes were investigated—direct laser ablation of ZnO:Al/CIGS films with a variable pulse duration of a femtosecond laser and the laser-induced material removal with a picosecond laser in the ZnO:Al/CZTSe structure. It has been found that the pulse energy and the number of laser pulses have a significantly stronger effect on the ablation quality in ZnO:Al/CIGS thin films rather than the laser pulse duration. For the thin-film scribing applications, it is very important to carefully select the processing parameters and use of ultra-short femtosecond pulses does not have a significant advantage compared to picosecond laser pulses. Investigations with the ZnO:Al/CZTSe thin films showed that process of the absorber layer removal was triggered by a micro-explosive effect induced by high pressure of sublimated material due to a rapid temperature increase at the molybdenum-CZTSe interface.

  8. Progress in Thin Film Solar Cells Based on Cu2ZnSnS4

    OpenAIRE

    Hongxia Wang

    2011-01-01

    The research in thin film solar cells has been dominated by light absorber materials based on CdTe and Cu(In,Ga)Se2 (CIGS) in the last several decades. The concerns of environment impact of cadmium and the limited availability of indium in those materials have driven the research towards developing new substitute light absorbers made from earth abundant, environment benign materials. Cu2ZnSnS4 (CZTS) semiconductor material has emerged as one of the most promising candidates for this aim and h...

  9. Characterization of solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Haerkoenen, J.; Tuominen, E.; Nybergh, K.; Ezer, Y.; Yli-Koski, M.; Sinkkonen, J. [Helsinki Univ. of Technology (Finland). Dept. of Electrical and Communications Engineering

    1998-12-31

    Photovoltaic research began at the Electron Physics Laboratory of the Helsinki University of Tehnology in 1993, when the laboratory joined the national NEMO 2 research program. During the early stages of the photovoltaic research the main objective was to establish necessary measurement and characterisation routines, as well as to develop the fabrication process. The fabrication process development work has been supported by characterisation and theoretical modelling of the solar cells. Theoretical investigations have been concerned with systematic studies of solar cell parameters, such as diffusion lengths, surface recombination velocities and junction depths. The main result of the modelling and characterisation work is a method which is based on a Laplace transform of the so-called spatial collection efficiency function of the cell. The basic objective of the research has been to develop a fabrication process cheap enough to be suitable for commercial production

  10. Recycling of Indium From CIGS Photovoltaic Cells: Potential of Combining Acid-Resistant Nanofiltration with Liquid-Liquid Extraction.

    NARCIS (Netherlands)

    Zimmermann, Y.S.; Niewersch, C.; Lenz, M.; Corvini, P.F.X.; Schäffer, A.; Wintgens, T.

    2014-01-01

    Electronic consumer products such as smartphones, TV, computers, light-emitting diodes, and photovoltaic cells crucially depend on metals and metalloids. So-called “urban mining” considers them as secondary resources since they may contain precious elements at concentrations many times higher than t

  11. Alternative Window Schemes for CuInSe2-Based Solar Cells Final Report: 3 November 1995-December 1997

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, L.C. (Electronic Materials Laboratory: Washington State University at Tri-Cities)

    1998-10-26

    This work demonstrated high-efficiency CIGS cells based on highly resistive ZnO buffer layers grown by MOCVD. One cell based on NREL CIGS and a ZnO buffer layer exhibited an active-area efficiency of nearly 14%. This result is one of the best efficiencies reported for a ''direct'' ZnO/CIGS cell made with a vacuum process.

  12. Loss mechanisms in hydrazine-processed Cu2ZnSn(Se,S)4 solar cells

    Science.gov (United States)

    Gunawan, Oki; Todorov, Teodor K.; Mitzi, David B.

    2010-12-01

    We present a device characterization study for hydrazine-processed kesterite Cu2ZnSn(Se,S)4 (CZTSSe) solar cells with a focus on pinpointing the main loss mechanisms limiting device efficiency. Temperature-dependent study and time-resolved photoluminescence spectroscopy on these cells, in comparison to analogous studies on a reference Cu(In,Ga)(Se,S)2 (CIGS) cell, reveal strong recombination loss at the CZTSSe/CdS interface, very low minority-carrier lifetimes, and high series resistance that diverges at low temperature. These findings help identify the key areas for improvement of these CZTSSe cells in the quest for a high-performance indium- and tellurium-free solar cell.

  13. Behavior of deep level defects on voltage-induced stress of Cu(In,Ga)Se2 solar cells

    International Nuclear Information System (INIS)

    The behavior of deep level defects by a voltage-induced stress for CuInGaSe2 (CIGS) solar cells has been investigated. CIGS solar cells were used with standard structures which are Al-doped ZnO/i-ZnO/CdS/CIGSe2/Mo on soda lime glass, and that resulted in conversion efficiencies as high as 16%. The samples with the same structure were isothermally stressed at 100 °C under the reverse voltages. The voltage-induced stressing in CIGS samples causes a decrease in the carrier density and conversion efficiency. To investigate the behavior of deep level defects in the stressed CIGS cells, photo-induced current transient spectroscopy was utilized, and normally 3 deep level defects (including 2 hole traps and 1 electron trap) were found to be located at 0.18 eV and 0.29 eV above the valence band maximum (and 0.36 eV below the conduction band). In voltage-induced cells, especially, it was found that the decrease of the hole carrier density could be responsible for the increase of the 0.29 eV defect, which is known to be observed in less efficient CIGS solar cells. And the carrier density and the defects are reversible at least to a large extent by resting at room-temperature without the bias voltage. From optical capture kinetics in photo-induced current transient spectroscopy measurement, the types of defects could be distinguished into the isolated point defect and the extended defect. In this work, it is suggested that the increase of the 0.29 eV defect by voltage-induced stress could be due to electrical activation accompanied by a loss of positive ion species and the activated defect gives rise to reduction of the carrier density. - Highlights: • We investigated behavior of deep level defects by voltage-induced stress. • Defect generation could affect the decrease of the conversion efficiency of cells. • Defect generation could be electrically activated by a loss of positive ion species. • Type of defects could be studied with models of point defects and

  14. Behavior of deep level defects on voltage-induced stress of Cu(In,Ga)Se{sub 2} solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Lee, D.W.; Cho, S.E. [Department of Physics and Semiconductor Science, Dongguk University, Seoul (Korea, Republic of); Jeong, J.H. [Solar Cell Center, Korea Institute of Science and Technology, Seoul (Korea, Republic of); Cho, H.Y., E-mail: hycho@dongguk.edu [Department of Physics and Semiconductor Science, Dongguk University, Seoul (Korea, Republic of)

    2015-05-01

    The behavior of deep level defects by a voltage-induced stress for CuInGaSe{sub 2} (CIGS) solar cells has been investigated. CIGS solar cells were used with standard structures which are Al-doped ZnO/i-ZnO/CdS/CIGSe{sub 2}/Mo on soda lime glass, and that resulted in conversion efficiencies as high as 16%. The samples with the same structure were isothermally stressed at 100 °C under the reverse voltages. The voltage-induced stressing in CIGS samples causes a decrease in the carrier density and conversion efficiency. To investigate the behavior of deep level defects in the stressed CIGS cells, photo-induced current transient spectroscopy was utilized, and normally 3 deep level defects (including 2 hole traps and 1 electron trap) were found to be located at 0.18 eV and 0.29 eV above the valence band maximum (and 0.36 eV below the conduction band). In voltage-induced cells, especially, it was found that the decrease of the hole carrier density could be responsible for the increase of the 0.29 eV defect, which is known to be observed in less efficient CIGS solar cells. And the carrier density and the defects are reversible at least to a large extent by resting at room-temperature without the bias voltage. From optical capture kinetics in photo-induced current transient spectroscopy measurement, the types of defects could be distinguished into the isolated point defect and the extended defect. In this work, it is suggested that the increase of the 0.29 eV defect by voltage-induced stress could be due to electrical activation accompanied by a loss of positive ion species and the activated defect gives rise to reduction of the carrier density. - Highlights: • We investigated behavior of deep level defects by voltage-induced stress. • Defect generation could affect the decrease of the conversion efficiency of cells. • Defect generation could be electrically activated by a loss of positive ion species. • Type of defects could be studied with models of point defects

  15. Development and manufacture of reactive-transfer-printed CIGS photovoltaic modules

    Science.gov (United States)

    Eldada, Louay; Sang, Baosheng; Lu, Dingyuan; Stanbery, Billy J.

    2010-09-01

    In recent years, thin-film photovoltaic (PV) companies started realizing their low manufacturing cost potential, and grabbing an increasingly larger market share from multicrystalline silicon companies. Copper Indium Gallium Selenide (CIGS) is the most promising thin-film PV material, having demonstrated the highest energy conversion efficiency in both cells and modules. However, most CIGS manufacturers still face the challenge of delivering a reliable and rapid manufacturing process that can scale effectively and deliver on the promise of this material system. HelioVolt has developed a reactive transfer process for CIGS absorber formation that has the benefits of good compositional control, high-quality CIGS grains, and a fast reaction. The reactive transfer process is a two stage CIGS fabrication method. Precursor films are deposited onto substrates and reusable print plates in the first stage, while in the second stage, the CIGS layer is formed by rapid heating with Se confinement. High quality CIGS films with large grains were produced on a full-scale manufacturing line, and resulted in high-efficiency large-form-factor modules. With 14% cell efficiency and 12% module efficiency, HelioVolt started to commercialize the process on its first production line with 20 MW nameplate capacity.

  16. Nanowire Solar Cells

    Science.gov (United States)

    Garnett, Erik C.; Brongersma, Mark L.; Cui, Yi; McGehee, Michael D.

    2011-08-01

    The nanowire geometry provides potential advantages over planar wafer-based or thin-film solar cells in every step of the photoconversion process. These advantages include reduced reflection, extreme light trapping, improved band gap tuning, facile strain relaxation, and increased defect tolerance. These benefits are not expected to increase the maximum efficiency above standard limits; instead, they reduce the quantity and quality of material necessary to approach those limits, allowing for substantial cost reductions. Additionally, nanowires provide opportunities to fabricate complex single-crystalline semiconductor devices directly on low-cost substrates and electrodes such as aluminum foil, stainless steel, and conductive glass, addressing another major cost in current photovoltaic technology. This review describes nanowire solar cell synthesis and fabrication, important characterization techniques unique to nanowire systems, and advantages of the nanowire geometry.

  17. Effect of substrate temperatures on evaporated In2S3 thin film buffer layers for Cu(In,Ga)Se2 solar cells

    International Nuclear Information System (INIS)

    For the realization of vacuum in-line process in the fabrication of Cu(In,Ga)Se2 (CIGS) solar cells, In2S3 thin film buffer layers for CIGS have been deposited on glasses and CIGS layers with a thickness of about 650 Å by thermal evaporation process. During the thermal evaporation, the temperature of the substrate was varied from room temperature to 500 °C by heating and the grown In2S3 films were investigated and analyzed in terms of the optimized buffer layer for CIGS solar cells. From the results of scanning electron microscope and X-ray diffraction, the In2S3 thin film deposited at a higher substrate temperature showed the larger grain size and the films have amorphous structural characteristics. Although the structural characteristics such as the atomic ratio of In to S and transmittance of the In2S3 thin films were not proportional to temperature, it was possible to obtain the large optical band gap of In2S3 films of about 3.8–3.9 eV enough to be used as the buffer layer of CIGS. - Highlights: • In2S3 films were deposited at various substrate temperatures by thermal evaporation. • The atomic ratio of In to S in the In2S3 film has the highest value at 300 °C. • The In2S3 film has a band gap of about 3.8 eV because of its amorphous structure. • The In2S3 film is expected to be used as a buffer layer by in-line vacuum process

  18. Nanostructures for Organic Solar Cells

    DEFF Research Database (Denmark)

    Goszczak, Arkadiusz Jarosław

    2016-01-01

    The experimental work in this thesis is focused on the fabrication of nanostructures that can be implemented in organic solar cell (OSC) architecture for enhancement of the device performance. Solar devices made from organic material are gaining increased attention, compared to their inorganic...... for organic solar cell applications, opening new patterning possibilities....

  19. Transparent solar cell window module

    Energy Technology Data Exchange (ETDEWEB)

    Chau, Joseph Lik Hang; Chen, Ruei-Tang; Hwang, Gan-Lin; Tsai, Ping-Yuan [Nanopowder and Thin Film Technology Center, ITRI South, Industrial Technology Research Institute, Tainan County 709 (China); Lin, Chien-Chu [I-Lai Acrylic Corporation, Tainan City (China)

    2010-03-15

    A transparent solar cell window module based on the integration of traditional silicon solar cells and organic-inorganic nanocomposite material was designed and fabricated. The transparent solar cell window module was composed of a nanocomposite light-guide plate and traditional silicon solar cells. The preparation of the nanocomposite light-guide plate is easy without modification of the traditional casting process, the nanoparticles sol can be added directly to the polymethyl methacrylate (PMMA) monomer syrup during the process. The solar energy collected by this window can be used to power up small household electrical appliances. (author)

  20. Silicon heterojunction solar cells

    CERN Document Server

    Fahrner, W R; Neitzert, H C

    2006-01-01

    The world of today must face up to two contradictory energy problems: on the one hand, there is the sharply growing consumer demand in countries such as China and India. On the other hand, natural resources are dwindling. Moreover, many of those countries which still possess substantial gas and oil supplies are politically unstable. As a result, renewable natural energy sources have received great attention. Among these, solar-cell technology is one of the most promising candidates. However, there still remains the problem of the manufacturing costs of such cells. Many attempts have been made

  1. Carbon Nanotube Solar Cells

    OpenAIRE

    Klinger, Colin; Patel, Yogeshwari; Postma, Henk W. Ch.

    2012-01-01

    We present proof-of-concept all-carbon solar cells. They are made of a photoactive side of predominantly semiconducting nanotubes for photoconversion and a counter electrode made of a natural mixture of carbon nanotubes or graphite, connected by a liquid electrolyte through a redox reaction. The cells do not require rare source materials such as In or Pt, nor high-grade semiconductor processing equipment, do not rely on dye for photoconversion and therefore do not bleach, and are easy to fabr...

  2. Fiscal 1994 New Sunshine Program achievement report. Development of photovoltaic power generation system practicalization technology - Research on practicalization of thin-film solar cell manufacturing technology (Technology for higher quality - Development of CuInSe{sub 2} solar cell manufacturing technology); 1994 nendo taiyoko hatsuden system jitsuyoka gijutsu kaihatsu seika hokokusho. Usumaku taiyo denchi seizo gijutsu no jitsuyoka kenkyu (kohinshitsuka gijutsu (CuInSe{sub 2} taiyo denchi seizo no gijutsu kaihatsu))

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-03-01

    The aim is to develop solar cells that exhibit conversion efficiency of 12% in a 10cm times 10cm-large minimodule. When a substrate made of soda lime glass with an SiO{sub 2} coating thereon is used, high reproducibility is achieved in the manufacture of CuInSe{sub 2} (CIS) thin-film solar cells. For the manufacture of a high-quality Cu(InGa)Se{sub 2}(CIGS) light absorbing thin-film layer, it is necessary to develop high-quality precursor film manufacturing and gas phase selenization technologies. A laminated precursor film formed by sputtering is selenized in a H{sub 2}Se gas atmosphere for the formation of CuInSe{sub 2} and CIGS light absorbing thin-film layers, and 16 ZnO/CdS/CIS-structured thin film solar cells built into a 10cm times 10cm-large substrate exhibit conversion efficiency of 11.6%. A CIGS cell using a sulfur-containing Zn compound buffer layer exhibits conversion efficiency of 12.1%. Conditions for the manufacture of a ZnO:Al transparent conductive film are studied. Dependence of CIS-based solar cell output characteristics on temperature and irradiation may be compensated for under the JIS (Japanese Industrial Standard) compensatory formula. The CIS-based thin-film solar cell suffers but a little reduction in output due to temperature rise, and may be therefore said to be excellent. (NEDO)

  3. Space solar cells - tradeoff analysis

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, M.R. [ISRO Satellite Centre, Bangalore (India). Power Systems Group

    2003-05-15

    This paper summarizes the study that had the objective to tradeoff space solar cells and solar array designs to determine the best choice of solar cell and array technology that would be more beneficial in terms of mass, area and cost for different types of space missions. Space solar cells, which are commercially now available in the market and to be available in the near future, were considered for this trade study. Four solar array designs: rigid, flexible, thin film flexible and concentrator solar arrays were considered for assessment. Performance of the solar cells along with solar array designs were studied for two types of space missions:geo synchronous orbit (GEO) and low earth orbit (LEO) spacecraft. The Solar array designs assumed were to provide 15 kW power for 15 years mission life in GEO and 5 kW power for 5 years mission life in LEO altitudes. To perform tradeoff analysis a spread sheet model was developed that calculates the size, mass and estimates the cost of solar arrays based on different solar cell and array technologies for given set of mission requirements. Comparative performance metrics (W/kg, W/m{sup 2}, kg/m{sup 2}, and $/W) were calculated for all solar arrays studied and compared, at the solar array subsystem level and also at the spacecraft system level. The trade analysis results show that high-efficiency multijunction solar cells bring lot of cost advantages for both types of missions. The trade study also shows that thin film solar cells with moderate efficiency with ultra lightweight flexible array design may become competitive with well-established single crystalline solar cell technologies in the future. (author)

  4. Space solar cells. Tradeoff analysis

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, M. Raja [Power Systems Group, Solar Panels Division, ISRO Satellite Centre, Bangalore 560017 (India)

    2003-05-15

    This paper summarizes the study that had the objective to tradeoff space solar cells and solar array designs to determine the best choice of solar cell and array technology that would be more beneficial in terms of mass, area and cost for different types of space missions. Space solar cells, which are commercially now available in the market and to be available in the near future, were considered for this trade study. Four solar array designs: rigid, flexible, thin film flexible and concentrator solar arrays were considered for assessment. Performance of the solar cells along with solar array designs were studied for two types of space missions: geo synchronous orbit (GEO) and low earth orbit (LEO) spacecraft. The Solar array designs assumed were to provide 15kW power for 15 years mission life in GEO and 5kW power for 5 years mission life in LEO altitudes. To perform tradeoff analysis a spread sheet model was developed that calculates the size, mass and estimates the cost of solar arrays based on different solar cell and array technologies for given set of mission requirements. Comparative performance metrics (W/kg, W/m{sup 2}, kg/m{sup 2}, and $/W) were calculated for all solar arrays studied and compared, at the solar array subsystem level and also at the spacecraft system level. The trade analysis results show that high-efficiency multijunction solar cells bring lot of cost advantages for both types of missions. The trade study also show that thin film solar cells with moderate efficiency with ultra lightweight flexible array design may become competitive with well-established single crystalline solar cell technologies in the future.

  5. Optimization of the ZnS Buffer Layer by Chemical Bath Deposition for Cu(In,Ga)Se2 Solar Cells.

    Science.gov (United States)

    Jeon, Dong-Hwan; Hwang, Dae-Kue; Kim, Dae-Hwan; Kang, Jin-Kyu; Lee, Chang-Seop

    2016-05-01

    We evaluated a ZnS buffer layer prepared using a chemical bath deposition (CBD) process for application in cadmium-free Cu(In,Ga)Se2 (CIGS) solar cells. The ZnS buffer layer showed good transmittance (above 90%) in the spectral range from 300 to 800 nm and was non-toxic compared with the CdS buffer layers normally used in CIGS solar cells. The CBD process was affected by several deposition conditions. The deposition rate was dependent on the ammonia concentration (complexing agent). When the ammonia concentration was either too high or low, a decrease in the deposition rate was observed. In addition, post heat treatments at high temperatures had detrimental influences on the ZnS buffer layers because portions of the ZnS thin films were transformed into ZnO. With optimized deposition conditions, a CIGS solar cell with a ZnS buffer layer showed an efficiency of 14.18% with a 0.23 cm2 active area under 100 mW/cm2 illumination.

  6. Elemental depth profiling in Cu(In, Ga)Se 2 solar cells using micro-PIXE on a bevelled section

    Science.gov (United States)

    Spemann, D.; Otte, K.; Lorenz, M.; Butz, T.

    2005-04-01

    Cu(In, Ga)Se2 (CIGS) solar cells deposited on polyimide foils by the Solarion company in a web-coater based process using sputter and evaporation techniques were investigated in the ion beam laboratory LIPSION of the University of Leipzig by means of Rutherford Backscattering Spectrometry (RBS) and Particle Induced X-ray Emission (PIXE) using a 2.25 MeV proton microbeam. From these measurements the composition of the absorber as well as the lateral homogeneity and the film thicknesses of the individual layers of the solar cell could be determined under some reasonable assumptions. Quantitative depth profiling of the individual elements was performed by micro-PIXE measurements on a bevelled section of a CIGS solar cell prepared by ion beam etching. It revealed small concentration-depth-gradients for Cu, In, Ga and Se within the CIGS absorber layer. Furthermore, a remarkable amount of Cd from the overlying CdS buffer layer was found to be present in the absorber layer. Secondary Neutral Mass Spectrometry (SNMS) measurements were applied on the same samples for comparison.

  7. Beneficial effect of post-deposition treatment in high-efficiency Cu(In,Ga)Se2 solar cells through reduced potential fluctuations

    Science.gov (United States)

    Jensen, S. A.; Glynn, S.; Kanevce, A.; Dippo, P.; Li, J. V.; Levi, D. H.; Kuciauskas, D.

    2016-08-01

    World-record power conversion efficiencies for Cu(In,Ga)Se2 (CIGS) solar cells have been achieved via a post-deposition treatment with alkaline metals, which increases the open-circuit voltage and fill factor. We explore the role of the potassium fluoride (KF) post-deposition treatment in CIGS by employing energy- and time-resolved photoluminescence spectroscopy and electrical characterization combined with numerical modeling. The bulk carrier lifetime is found to increase with post-deposition treatment from 255 ns to 388 ns, which is the longest charge carrier lifetime reported for CIGS, and within ˜40% of the radiative limit. We find evidence that the post-deposition treatment causes a decrease in the electronic potential fluctuations. These potential fluctuations have previously been shown to reduce the open-circuit voltage and the device efficiency in CIGS. Additionally, numerical simulations based on the measured carrier lifetimes and mobilities show a diffusion length of ˜10 μm, which is ˜4 times larger than the film thickness. Thus, carrier collection in the bulk is not a limiting factor for device efficiency. By considering differences in doping, bandgap, and potential fluctuations, we present a possible explanation for the voltage difference between KF-treated and untreated samples.

  8. Beneficial Effect of Post-Deposition Treatment in High-Efficiency Cu(In,Ga)Se2 Solar Cells through Reduced Potential Fluctuations

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Soren A.; Glynn, Stephen; Kanevce, Ana; Dippo, Pat; Li, Jian V.; Levi, Dean H.; Kuciauskas, Darius

    2016-08-14

    World-record power conversion efficiencies for Cu(In,Ga)Se2 (CIGS) solar cells have been achieved via a post-deposition treatment with alkaline metals, which increases the open-circuit voltage and fill factor. We explore the role of the potassium fluoride (KF) post-deposition treatment in CIGS by employing energy- and time-resolved photoluminescence spectroscopy and electrical characterization combined with numerical modeling. The bulk carrier lifetime is found to increase with post-deposition treatment from 255 ns to 388 ns, which is the longest charge carrier lifetime reported for CIGS, and within ~40% of the radiative limit. We find evidence that the post-deposition treatment causes a decrease in the electronic potential fluctuations. These potential fluctuations have previously been shown to reduce the open-circuit voltage and the device efficiency in CIGS. Additionally, numerical simulations based on the measured carrier lifetimes and mobilities show a diffusion length of ~10 um, which is ~4 times larger than the film thickness. Thus, carrier collection in the bulk is not a limiting factor for device efficiency. By considering differences in doping, bandgap, and potential fluctuations, we present a possible explanation for the voltage difference between KF-treated and untreated samples.

  9. Efficiency enhancement calculations of state-of-the-art solar cells by luminescent layers with spectral shifting, quantum cutting, and quantum tripling function

    OpenAIRE

    Kate, ten, F.J.W.; Jong, de, T.; Hintzen, HTJM Bert; Kolk, van der, J.P.

    2013-01-01

    Solar cells of which the efficiency is not limited by the Shockley-Queisser limit can be obtained by integrating a luminescent spectral conversion layer into the cell structure. We have calculated the maximum efficiency of state-of-the-art c-Si, pc-Si, a-Si, CdTe, GaAs, CIS, CIGS, CGS, GaSb, and Ge solar cells with and without an integrated spectral shifting, quantum cutting, or quantum tripling layer using their measured internal quantum efficiency (IQE) curves. Our detailed balance limit ca...

  10. Performance of Photovoltaic Modules of Different Solar Cells

    Directory of Open Access Journals (Sweden)

    Ankita Gaur

    2013-01-01

    Full Text Available In this paper, an attempt of performance evaluation of semitransparent and opaque photovoltaic (PV modules of different generation solar cells, having the maximum efficiencies reported in the literature at standard test conditions (STC, has been carried out particularly for the months of January and June. The outdoor performance is also evaluated for the commercially available semitransparent and opaque PV modules. Annual electrical energy, capitalized cost, annualized uniform cost (unacost, and cost per unit electrical energy for both types of solar modules, namely, semitransparent and opaque have also been computed along with their characteristics curves. Semitransparent PV modules have shown higher efficiencies compared to the opaque ones. Calculations show that for the PV modules made in laboratory, CdTe exhibits the maximum annual electrical energy generation resulting into minimum cost per unit electrical energy, whereas a-Si/nc-Si possesses the maximum annual electrical energy generation giving minimum cost per unit electrical energy when commercially available solar modules are concerned. CIGS has shown the lowest capitalized cost over all other PV technologies.

  11. Cascade Organic Solar Cells

    KAUST Repository

    Schlenker, Cody W.

    2011-09-27

    We demonstrate planar organic solar cells consisting of a series of complementary donor materials with cascading exciton energies, incorporated in the following structure: glass/indium-tin-oxide/donor cascade/C 60/bathocuproine/Al. Using a tetracene layer grown in a descending energy cascade on 5,6-diphenyl-tetracene and capped with 5,6,11,12-tetraphenyl- tetracene, where the accessibility of the π-system in each material is expected to influence the rate of parasitic carrier leakage and charge recombination at the donor/acceptor interface, we observe an increase in open circuit voltage (Voc) of approximately 40% (corresponding to a change of +200 mV) compared to that of a single tetracene donor. Little change is observed in other parameters such as fill factor and short circuit current density (FF = 0.50 ± 0.02 and Jsc = 2.55 ± 0.23 mA/cm2) compared to those of the control tetracene-C60 solar cells (FF = 0.54 ± 0.02 and Jsc = 2.86 ± 0.23 mA/cm2). We demonstrate that this cascade architecture is effective in reducing losses due to polaron pair recombination at donor-acceptor interfaces, while enhancing spectral coverage, resulting in a substantial increase in the power conversion efficiency for cascade organic photovoltaic cells compared to tetracene and pentacene based devices with a single donor layer. © 2011 American Chemical Society.

  12. Solar cell materials developing technologies

    CERN Document Server

    Conibeer, Gavin J

    2014-01-01

    This book presents a comparison of solar cell materials, including both new materials based on organics, nanostructures and novel inorganics and developments in more traditional photovoltaic materials. It surveys the materials and materials trends in the field including third generation solar cells (multiple energy level cells, thermal approaches and the modification of the solar spectrum) with an eye firmly on low costs, energy efficiency and the use of abundant non-toxic materials.

  13. Thermal Management of Solar Cells

    OpenAIRE

    Saadah, Mohammed Ahmed

    2013-01-01

    The focus on solar cells as a source of photovoltaic energy is rapidly increasing nowadays. The amount of sun's energy entering earth surface in one hour is more than the world consume in one year. The photovoltaic market has been increasing by more than 20% annually since 2002. Improving solar cells aims at increasing the power conversion efficiency and reducing manufacturing costs. Crystalline silicon is the most commonly used material in making solar cells with more than 90% market use. So...

  14. Diffused quantum well solar cell

    OpenAIRE

    Lee, ASW; Li, EH; Cheng, Y

    1995-01-01

    An alternative multi-bandgap solar cell made of diffused quantum well (DFQW) as the absorber is proposed here. The modeling of the spectral response and energy conversion efficiency of the solar cell will be shown. Significant enhancement in energy conversion efficiency is demonstrated when compared to that of the single bandgap cells.

  15. Bifacial tandem solar cells

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-06-14

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

  16. Dye Sensitized Solar Cell, DSSC

    Directory of Open Access Journals (Sweden)

    Pongsatorn Amornpitoksuk

    2003-07-01

    Full Text Available A dye sensitized solar cell is a new type of solar cell. The operating system of this solar cell type is similar to plant’s photosynthesis process. The sensitizer is available for absorption light and transfer electrons to nanocrystalline metal oxide semiconductor. The ruthenium(II complexes with polypyridyl ligands are usually used as the sensitizers in solar cell. At the present time, the complex of [Ru(2,2',2'’-(COOH3- terpy(NCS3] is the most efficient sensitizer. The total photon to current conversion efficiency was approximately 10% at AM = 1.5.

  17. Space Solar Cell Characterization Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Measures, characterizes, and analyzes photovoltaic materials and devices. The primary focus is the measurement and characterization of solar cell response...

  18. A comparative study on charge carrier recombination across the junction region of Cu2ZnSn(S,Se4 and Cu(In,GaSe2 thin film solar cells

    Directory of Open Access Journals (Sweden)

    Mohammad Abdul Halim

    2016-03-01

    Full Text Available A comparative study with focusing on carrier recombination properties in Cu2ZnSn(S,Se4 (CZTSSe and the CuInGaSe2 (CIGS solar cells has been carried out. For this purpose, electroluminescence (EL and also bias-dependent time resolved photoluminescence (TRPL using femtosecond (fs laser source were performed. For the similar forward current density, the EL-intensity of the CZTSSe sample was obtained significantly lower than that of the CIGS sample. Primarily, it can be attributed to the existence of excess amount of non-radiative recombination center in the CZTSSe, and/or CZTSSe/CdS interface comparing to that of CIGS sample. In case of CIGS sample, TRPL decay time was found to increase with the application of forward-bias. This can be attributed to the reduced charge separation rate resulting from the reduced electric-field at the junction. However, in CZTSSe sample, TRPL decay time has been found almost independent under the forward and reverse-bias conditions. This phenomenon indicates that the charge recombination rate strongly dominates over the charge separation rate across the junction of the CZTSSe sample. Finally, temperature dependent VOC suggests that interface related recombination in the CZTSSe solar cell structure might be one of the major factors that affect EL-intensity and also, TRPL decay curves.

  19. Quantum Junction Solar Cells

    KAUST Repository

    Tang, Jiang

    2012-09-12

    Colloidal quantum dot solids combine convenient solution-processing with quantum size effect tuning, offering avenues to high-efficiency multijunction cells based on a single materials synthesis and processing platform. The highest-performing colloidal quantum dot rectifying devices reported to date have relied on a junction between a quantum-tuned absorber and a bulk material (e.g., TiO 2); however, quantum tuning of the absorber then requires complete redesign of the bulk acceptor, compromising the benefits of facile quantum tuning. Here we report rectifying junctions constructed entirely using inherently band-aligned quantum-tuned materials. Realizing these quantum junction diodes relied upon the creation of an n-type quantum dot solid having a clean bandgap. We combine stable, chemically compatible, high-performance n-type and p-type materials to create the first quantum junction solar cells. We present a family of photovoltaic devices having widely tuned bandgaps of 0.6-1.6 eV that excel where conventional quantum-to-bulk devices fail to perform. Devices having optimal single-junction bandgaps exhibit certified AM1.5 solar power conversion efficiencies of 5.4%. Control over doping in quantum solids, and the successful integration of these materials to form stable quantum junctions, offers a powerful new degree of freedom to colloidal quantum dot optoelectronics. © 2012 American Chemical Society.

  20. Carbon nanotube solar cells.

    Directory of Open Access Journals (Sweden)

    Colin Klinger

    Full Text Available We present proof-of-concept all-carbon solar cells. They are made of a photoactive side of predominantly semiconducting nanotubes for photoconversion and a counter electrode made of a natural mixture of carbon nanotubes or graphite, connected by a liquid electrolyte through a redox reaction. The cells do not require rare source materials such as In or Pt, nor high-grade semiconductor processing equipment, do not rely on dye for photoconversion and therefore do not bleach, and are easy to fabricate using a spray-paint technique. We observe that cells with a lower concentration of carbon nanotubes on the active semiconducting electrode perform better than cells with a higher concentration of nanotubes. This effect is contrary to the expectation that a larger number of nanotubes would lead to more photoconversion and therefore more power generation. We attribute this to the presence of metallic nanotubes that provide a short for photo-excited electrons, bypassing the load. We demonstrate optimization strategies that improve cell efficiency by orders of magnitude. Once it is possible to make semiconducting-only carbon nanotube films, that may provide the greatest efficiency improvement.

  1. An Introduction to Solar Cells

    Science.gov (United States)

    Feldman, Bernard J.

    2010-01-01

    Most likely, solar cells will play a significant role in this country's strategy to address the two interrelated issues of global warming and dependence on imported oil. The purpose of this paper is to present an explanation of how solar cells work at an introductory high school, college, or university physics course level. The treatment presented…

  2. Performance improvement of CdS/Cu(In,Ga)Se2 solar cells after rapid thermal annealing

    Institute of Scientific and Technical Information of China (English)

    Chen Dong-Sheng; Yang Jie; Xu Fei; Zhou Ping-Hua; Du Hui-Wei; Shi Jian-Wei; Yu Zheng-Shan

    2013-01-01

    In this paper,we investigated the effect of rapid thermal annealing (RTA) on solar cell performance.An opto-electric conversion efficiency of 11.75% (Voc =0.64 V,Jsc =25.88 mA/cm2,FF=72.08%) was obtained under AM 1.5G when the cell was annealed at 300 ℃ for 30 s.The annealed solar cell showed an average absolute efficiency 1.5% higher than that of the as-deposited one.For the microstructure analysis and the physical phase confirmation,X-ray diffraction (XRD),Raman spectra,front surface reflection (FSR),internal quantum efficiency (IQE),and X-ray photoelectron spectroscopy (XPS) were respectively applied to distinguish the causes inducing the efficiency variation.All experimental results implied that the RTA eliminated recombination centers at the p-n junction,reduced the surface optical losses,enhanced the blue response of the CdS buffer layer,and improved the ohmic contact between Mo and Cu(In,Ga)Se2 (CIGS) layers.This leaded to the improved performance of CIGS solar cell.

  3. Back wall solar cell

    Science.gov (United States)

    Brandhorst, H. W., Jr. (Inventor)

    1978-01-01

    A solar cell is disclosed which comprises a first semiconductor material of one conductivity type with one face having the same conductivity type but more heavily doped to form a field region arranged to receive the radiant energy to be converted to electrical energy, and a layer of a second semiconductor material, preferably highly doped, of opposite conductivity type on the first semiconductor material adjacent the first semiconductor material at an interface remote from the heavily doped field region. Instead of the opposite conductivity layer, a metallic Schottky diode layer may be used, in which case no additional back contact is needed. A contact such as a gridded contact, previous to the radiant energy may be applied to the heavily doped field region of the more heavily doped, same conductivity material for its contact.

  4. Upconversion in solar cells.

    Science.gov (United States)

    van Sark, Wilfried Gjhm; de Wild, Jessica; Rath, Jatin K; Meijerink, Andries; Schropp, Ruud Ei

    2013-02-15

    The possibility to tune chemical and physical properties in nanosized materials has a strong impact on a variety of technologies, including photovoltaics. One of the prominent research areas of nanomaterials for photovoltaics involves spectral conversion. Modification of the spectrum requires down- and/or upconversion or downshifting of the spectrum, meaning that the energy of photons is modified to either lower (down) or higher (up) energy. Nanostructures such as quantum dots, luminescent dye molecules, and lanthanide-doped glasses are capable of absorbing photons at a certain wavelength and emitting photons at a different (shorter or longer) wavelength. We will discuss upconversion by lanthanide compounds in various host materials and will further demonstrate upconversion to work for thin-film silicon solar cells.

  5. Progress in polymer solar cell

    Institute of Scientific and Technical Information of China (English)

    LI LiGui; LU GuangHao; YANG XiaoNiu; ZHOU EnLe

    2007-01-01

    This review outlines current progresses in polymer solar cell. Compared to traditional silicon-based photovoltaic (PV) technology, the completely different principle of optoelectric response in the polymer cell results in a novel configuration of the device and more complicated photovoltaic generation process. The conception of bulk-heterojunction (BHJ) is introduced and its advantage in terms of morphology is addressed. The main aspects including the morphology of photoactive layer, which limit the efficiency and stability of polymer solar cell, are discussed in detail. The solutions to boosting up both the efficiency and stability (lifetime) of the polymer solar cell are highlighted at the end of this review.

  6. Challenge of replacing CdS in CuInSe{sub 2}-based solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, L.C.; Addis, F.W.; Lei, W.; Aguilar, H. [Washington State University at Tri-Cities, 100 Sprout Rd., Richland, Washington 99352 (United States)

    1997-02-01

    This paper discusses some key issues concerning the replacement of CdS buffer layers in CIS solar cell structures, and describes investigations of alternative buffer layers deposited by MOCVD. One apparently unique property of CdS buffer layers grown by CBD is that a ZnO TCO can be deposited on top of a CdS/CIS structure without significantly degrading the photovoltaic properties of the CdS-CIS junction. Investigation of alternative buffer materials such as high resistance ZnO (i-ZnO), ZnSe and InSe have first identified MOCVD growth procedures that yield Al/X/CIS test structures (X=i-ZnO, ZnSe and InSe) with good properties, and then addressed the challenge of fabricating efficient, complete cells with conductive ZnO top contact layers. These studies have been conducted with Siemens CIS and CIGSS substrates, and with NREL CIGS substrates. A total area efficiency of 12.7{percent} and estimated active area efficiency of 13.4{percent} is reported for a CIGS cell with an i-ZnO buffer layer grown by MOCVD. {copyright} {ital 1997 American Institute of Physics.}

  7. Challenge of replacing CdS in CuInSe2-based solar cells

    Science.gov (United States)

    Olsen, Larry C.; Addis, F. William; Lei, Wenhua; Aguilar, Heriberto

    1997-02-01

    This paper discusses some key issues concerning the replacement of CdS buffer layers in CIS solar cell structures, and describes investigations of alternative buffer layers deposited by MOCVD. One apparently unique property of CdS buffer layers grown by CBD is that a ZnO TCO can be deposited on top of a CdS/CIS structure without significantly degrading the photovoltaic properties of the CdS-CIS junction. Investigation of alternative buffer materials such as high resistance ZnO (i-ZnO), ZnSe and InSe have first identified MOCVD growth procedures that yield Al/X/CIS test structures (X=i-ZnO, ZnSe and InSe) with good properties, and then addressed the challenge of fabricating efficient, complete cells with conductive ZnO top contact layers. These studies have been conducted with Siemens CIS and CIGSS substrates, and with NREL CIGS substrates. A total area efficiency of 12.7% and estimated active area efficiency of 13.4% is reported for a CIGS cell with an i-ZnO buffer layer grown by MOCVD.

  8. Photon management in solar cells

    CERN Document Server

    Rau, Uwe; Gombert, Andreas

    2015-01-01

    Written by renowned experts in the field of photon management in solar cells, this one-stop reference gives an introduction to the physics of light management in solar cells, and discusses the different concepts and methods of applying photon management. The authors cover the physics, principles, concepts, technologies, and methods used, explaining how to increase the efficiency of solar cells by splitting or modifying the solar spectrum before they absorb the sunlight. In so doing, they present novel concepts and materials allowing for the cheaper, more flexible manufacture of solar cells and systems. For educational purposes, the authors have split the reasons for photon management into spatial and spectral light management. Bridging the gap between the photonics and the photovoltaics communities, this is an invaluable reference for materials scientists, physicists in industry, experimental physicists, lecturers in physics, Ph.D. students in physics and material sciences, engineers in power technology, appl...

  9. Effective absorption coefficient for graded band-gap semiconductors and the expected photocurrent density in solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Morales-Acevedo, Arturo [CINVESTAV del IPN, Electrical Engineering Department, Avenida IPN No. 2508, 07360 Mexico, D. F. (Mexico)

    2009-01-15

    A simple model for the generation of carriers by photons incident on a (linearly) decreasing band-gap material, such as has been described in recent CIGS solar cells, is developed. The model can be generalized for different cases such as increasing band-gap grading or for having a more complex band-gap profile. The model developed for direct band semiconductors such as CIGS or AlGaAs allows us to define an effective absorption coefficient, so that the ideal photocurrent density can be calculated in a similar manner as for solar cells with non-graded band-gap materials. We show that this model gives completely different results as those expected from intuitive approaches for calculating this ideal photocurrent density. We also show that grading of the band-gap of the absorbing material in solar cells makes the photocurrent less sensitive to the total band-gap change, in such a way that the design of the band-gap variation can be more flexible in order to have other advantages such as higher built-in voltage or higher back surface field in the device structure. (author)

  10. Hydrogenated indium oxide window layers for high-efficiency Cu(In,Ga)Se2 solar cells

    International Nuclear Information System (INIS)

    High mobility hydrogenated indium oxide is investigated as a transparent contact for thin film Cu(In,Ga)Se2 (CIGS) solar cells. Hydrogen doping of In2O3 thin films is achieved by injection of H2O water vapor or H2 gas during the sputter process. As-deposited amorphous In2O3:H films exhibit a high electron mobility of ∼50 cm2/Vs at room temperature. A bulk hydrogen concentration of ∼4 at. % was measured for both optimized H2O and H2-processed films, although the H2O-derived film exhibits a doping gradient as detected by elastic recoil detection analysis. Amorphous IOH films are implemented as front contacts in CIGS based solar cells, and their performance is compared with the reference ZnO:Al electrodes. The most significant feature of IOH containing devices is an enhanced open circuit voltage (VOC) of ∼20 mV regardless of the doping approach, whereas the short circuit current and fill factor remain the same for the H2O case or slightly decrease for H2. The overall power conversion efficiency is improved from 15.7% to 16.2% by substituting ZnO:Al with IOH (H2O) as front contacts. Finally, stability tests of non-encapsulated solar cells in dry air at 80 °C and constant illumination for 500 h demonstrate a higher stability for IOH-containing devices

  11. Plastic Solar Cells: Understanding the Special Additive

    OpenAIRE

    van Franeker, Jacobus J.; Janssen, René A. J.

    2015-01-01

    Solar cells use freely available sunlight to make electricity. At the present time, solar electricity does not come cheap, because solar panels are rather expensive. Now imagine that we could reduce costs by printing solar panels like we print newspapers! We can do just that with plastic solar cells. In this article, we explain the basic working principles of these novel plastic solar cells and then show how a stunning threefold increase in solar energy efficiency can be achieved by including...

  12. Emitter/absorber interface of CdTe solar cells

    Science.gov (United States)

    Song, Tao; Kanevce, Ana; Sites, James R.

    2016-06-01

    The performance of CdTe solar cells can be very sensitive to the emitter/absorber interface, especially for high-efficiency cells with high bulk lifetime. Performance losses from acceptor-type interface defects can be significant when interface defect states are located near mid-gap energies. Numerical simulations show that the emitter/absorber band alignment, the emitter doping and thickness, and the defect properties of the interface (i.e., defect density, defect type, and defect energy) can all play significant roles in the interface recombination. In particular, a type I heterojunction with small conduction-band offset (0.1 eV ≤ ΔEC ≤ 0.3 eV) can help maintain good cell efficiency in spite of high interface defect density, much like with Cu(In,Ga)Se2 (CIGS) cells. The basic principle is that positive ΔEC, often referred to as a "spike," creates an absorber inversion and hence a large hole barrier adjacent to the interface. As a result, the electron-hole recombination is suppressed due to an insufficient hole supply at the interface. A large spike (ΔEC ≥ 0.4 eV), however, can impede electron transport and lead to a reduction of photocurrent and fill-factor. In contrast to the spike, a "cliff" (ΔEC CdTe solar cells, but the CdS/CdTe interface is in the cliff category and is not favorable from the band-offset perspective. The ΔEC of other n-type emitter choices, such as (Mg,Zn)O, Cd(S,O), or (Cd,Mg)Te, can be tuned by varying the elemental ratio for an optimal positive value of ΔEC. These materials are predicted to yield higher voltages and would therefore be better candidates for the CdTe-cell emitter.

  13. Impact of Cu-rich growth on the Cu2ZnSnSe4 surface morphology and related solar cells behavior

    Science.gov (United States)

    Ding, Sun; Yang, Ge; Li, Zhang; Shengzhi, Xu; Ze, Chen; Ning, Wang; Xuejiao, Liang; Changchun, Wei; Ying, Zhao; Xiaodan, Zhang

    2016-01-01

    In order to study the influence of Cu-rich growth on the performance of the Cu2ZnSnSe4 (CZTSe) thin film solar cells, a multi-stage co-evaporation process is applied. The CZTSe films are grown at a lower substrate temperature to reduce the existence time of Cux Sey at the first period caused by the volatility of SnSex. This study examines the surface morphology and device performance in Cu-rich growth and close-to-stoichiometric growth. Although the grain size of Cu-rich growth film increases a little, the difference was not dramatic as the results of CIGS reported previously. A model based on the grain boundary migration theory is proposed to explain the experimental results. The mechanisms of Cu-rich growth between CZTSe and CIGS might be different. Project supported by the Specialized Research Fund for the PhD Program of Higher Education (No. 20120031110039).

  14. Analysis on the Performance of Copper Indium Gallium Selenide (CIGS Based Photovoltaic Thermal

    Directory of Open Access Journals (Sweden)

    Zulkepli Afzam

    2016-01-01

    Full Text Available This paper deals with the efficiency improvement of Copper Indium Gallium Selenide (CIGS Photovoltaic (PV and also solar thermal collector. Photovoltaic thermal (PV/T can improve overall efficiency for PV and also solve the problem of limited roof space at urban area. Objective of this study is to clarify the effect of mass flow rate on the efficiency of the PV/T system. A CIGS solar cell is used with rated output power 65 W and 1.18 m2 of area. 4 set of experiments were carried out, which were: thermal collector with 0.12 kg/s flow rate, PV/T with 0.12 kg/s flow rate, PV/T with 0.09 kg/s flow rate and PV. It was found that PV/T with 0.12 kg/s flow rate had the highest electrical efficiency, 2.92 %. PV/T with 0.09 kg/s flow rate had the lowest electrical efficiency, 2.68 %. It also had 2 % higher overall efficiency. The efficiency gained is low due to several factors. The rated output power of the PV is low for the area of 1.18 m2. The packing factor of the PV also need to be considered as it may not be operated at the optimal packing factor. Furthermore, aluminium sheet of the PV may affect the PV temperature due to high thermal conductivity. Further study on more values of mass flow rate and also other parameters that affect the efficiency of the PV/T is necessary.

  15. Fundamentals of thin solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Yablonovitch, E. [Univ. of California, Los Angeles, CA (United States)

    1995-08-01

    It is now widely recognized that thin solar cells can present certain advantages for performance and cost. This is particularly the case when light trapping in the semiconductor film is incorporated, as compensation for the diminished single path thickness of the solar cell. In a solar cell thinner than a minority carrier diffusion length, the current collection is of course very easy. More importantly the concentration of an equivalent number of carriers in a thinner volume results in a higher Free Energy, or open circuit voltage. This extra Free Energy may be regarded as due to the concentration factor, just as it would be for photons, electrons, or for any chemical species. The final advantage of a thin solar cell is in the diminished material usage, a factor of considerable importance when we consider the material cost of the high quality semiconductors which we hope to employ.

  16. Flexible Cu(In,Ga)Se2 Thin-Film Solar Cells on Polyimide Substrate by Low-Temperature Deposition Process

    Institute of Scientific and Technical Information of China (English)

    ZHANG Li; HE Qing; JIANG Wei-Long; LI Chang-Jian; SUN Yun

    2008-01-01

    The electrical and structural properties of polycrystalline Cu(In,Ga)Se2 films grown on polyimide (PI) substrates below 400℃ via one-stage and three-stage co-evaporation process have been investigated by x-ray diffraction spectra (XRD),scanning electron microscopy (SEM) and Hall effect measurement.As shown by XRD spectra,the stoichiometric CIGS films obtained by one-stage process exhibit the characteristic diffraction peaks of the (In0.68Ga0.32)2Se3 and Cu(In0.7Ga0.3)2Se.It is also found that the film structures indicate more columnar and compact than the three-stage process films from SEM images.The stoichiometric CIGS films obtained by three-stage process exhibit the coexistence of the secondary phase of (In0.68Ga0.32)2Se3,Cu2-xSe and Cu(In0.7Ga0.3)2Se.High net carrier concentration and sheet conductivity are also observed for this kind of film,related to the presence of Cu2-xSe phase.As a result,when the CIGS film growth temperature is below 400℃,the three-stage process is inefficient for solar cells.By using the one-stage co-evaporation process,the flexible CIGS solar cell on a PI substrate with the best conversion efficiency of 6.38% is demonstrated (active area 0.16cm2).

  17. Manufacturing technology development for CuInGaSe{sub 2} solar cell modules. Final subcontract report, 9 January 1991--14 April 1991

    Energy Technology Data Exchange (ETDEWEB)

    Stanbery, B.J. [Boeing Aerospace and Electronics Co., Seattle, WA (US)

    1991-11-01

    The report describes research performed by Boeing Aerospace and Electronics under the Photovoltaic Manufacturing Technology project. We anticipate that implementing advanced semiconductor device fabrication techniques to the production of large-area CuIn{sub 1-x}Ga{sub x}Se{sub 2} (CIGS)/Cd{sub 1-y}Zn{sub y}S/ZnO monolithically integrated thin-film solar cell modules will enable 15% median efficiencies to be achieved in high-volume manufacturing. We do not believe that CuInSe{sub 2} (CIS) can achieve this efficiency in production without sufficient gallium to significantly increase the band gap, thereby matching it better to the solar spectrum (i.e., x{>=}0.2). Competing techniques for CIS film formation have not been successfully extended to CIGS devices with such high band gaps. The SERI-confirmed intrinsic stability of CIS-based photovoltaics renders them far superior to a-Si:H-based devices, making a 30-year module lifetime feasible. The minimal amounts of cadmium used in the structure we propose, compared to CdTe-based devices, makes them environmentally safer and more acceptable to both consumers and relevant regulatory agencies. Large-area integrated thin-film CIGS modules are the product most likely to supplant silicon modules by the end of this decade and enable the cost improvements which will lead to rapid market expansion.

  18. Solar cell with back side contacts

    Energy Technology Data Exchange (ETDEWEB)

    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.

  19. Thin-film solar cell

    NARCIS (Netherlands)

    Metselaar, J.W.; Kuznetsov, V.I.

    1998-01-01

    The invention relates to a thin-film solar cell provided with at least one p-i-n junction comprising at least one p-i junction which is at an angle alpha with that surface of the thin-film solar cell which collects light during operation and at least one i-n junction which is at an angle beta with t

  20. Thin film CIGS photovoltaic modules: monolithic integration and advanced packaging for high performance, high reliability and low cost

    Science.gov (United States)

    Eldada, Louay

    2011-01-01

    In recent years, thin-film photovoltaic companies started realizing their low manufacturing cost potential, and have been grabbing an increasingly larger market share. Copper Indium Gallium Selenide (CIGS) is the most promising thin-film PV material, having demonstrated the highest energy conversion efficiency in both cells and modules. However, most CIGS manufacturers still face the challenge of delivering a reliable and rapid manufacturing process that can scale effectively and deliver on the promise of this material system. HelioVolt has developed a reactive transfer process for CIGS absorber formation that has the benefits of good compositional control, and a fast high-quality CIGS reaction. The reactive transfer process is a two stage CIGS fabrication method. Precursor films are deposited onto substrates and reusable cover plates in the first stage, while in the second stage the CIGS layer is formed by rapid heating with Se confinement. HelioVolt also developed best-in-class packaging technologies that provide unparalleled environmental stability. High quality CIGS films with large grains were fabricated on the production line, and high-performance highreliability monolithic modules with a form factor of 120 cm × 60 cm are being produced at high yield and low cost. With conversion efficiency levels around 14% for cells and 12% for modules, HelioVolt is commercializing the process on its first production line with 20 MW capacity, and is planning its next GW-scale factory.

  1. Industrial Silicon Wafer Solar Cells

    Directory of Open Access Journals (Sweden)

    Dirk-Holger Neuhaus

    2007-01-01

    Full Text Available In 2006, around 86% of all wafer-based silicon solar cells were produced using screen printing to form the silver front and aluminium rear contacts and chemical vapour deposition to grow silicon nitride as the antireflection coating onto the front surface. This paper reviews this dominant solar cell technology looking into state-of-the-art equipment and corresponding processes for each process step. The main efficiency losses of this type of solar cell are analyzed to demonstrate the future efficiency potential of this technology. In research and development, more various advanced solar cell concepts have demonstrated higher efficiencies. The question which arises is “why are new solar cell concepts not transferred into industrial production more frequently?”. We look into the requirements a new solar cell technology has to fulfill to have an advantage over the current approach. Finally, we give an overview of high-efficiency concepts which have already been transferred into industrial production.

  2. Comparison of manufactured and modeled solar cell

    OpenAIRE

    Strachala, D.; Hylský, J.

    2015-01-01

    The aim of the work is to compare the model of monocrystalline silicon solar cell in PC1D with the real solar cell structure in terms of using a model in manufacture process. Real solar cell was firstly measured and analyzed to determine input parameters for a simulation and then realized in free available PC1D software. Degree of conformity of modeled and real solar cell was in the end established for basic prediction of solar cell parameters before manufacturing process.

  3. Solar electron source and thermionic solar cell

    Directory of Open Access Journals (Sweden)

    Parham Yaghoobi

    2012-12-01

    Full Text Available Common solar technologies are either photovoltaic/thermophotovoltaic, or use indirect methods of electricity generation such as boiling water for a steam turbine. Thermionic energy conversion based on the emission of electrons from a hot cathode into vacuum and their collection by an anode is also a promising route. However, thermionic solar conversion is extremely challenging as the sunlight intensity is too low for heating a conventional cathode to thermionic emission temperatures in a practical manner. Therefore, compared to other technologies, little has been done in this area, and the devices have been mainly limited to large experimental apparatus investigated for space power applications. Based on a recently observed “Heat Trap” effect in carbon nanotube arrays, allowing their efficient heating with low-power light, we report the first compact thermionic solar cell. Even using a simple off-the-shelf focusing lens, the device delivered over 1 V across a load. The device also shows intrinsic storage capacity.

  4. Advances in Perovskite Solar Cells

    Science.gov (United States)

    Zuo, Chuantian; Bolink, Henk J.; Han, Hongwei; Huang, Jinsong

    2016-01-01

    Organolead halide perovskite materials possess a combination of remarkable optoelectronic properties, such as steep optical absorption edge and high absorption coefficients, long charge carrier diffusion lengths and lifetimes. Taken together with the ability for low temperature preparation, also from solution, perovskite‐based devices, especially photovoltaic (PV) cells have been studied intensively, with remarkable progress in performance, over the past few years. The combination of high efficiency, low cost and additional (non‐PV) applications provides great potential for commercialization. Performance and applications of perovskite solar cells often correlate with their device structures. Many innovative device structures were developed, aiming at large‐scale fabrication, reducing fabrication cost, enhancing the power conversion efficiency and thus broadening potential future applications. This review summarizes typical structures of perovskite solar cells and comments on novel device structures. The applications of perovskite solar cells are discussed.

  5. Novel wide band gap materials for highly efficient thin film tandem solar cells. Final report

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-06-11

    thin films using a mixture of solution and physical vapor deposition processing, but these films lacked the p-type doping levels that are required to make decent solar cells. Over the course of the project PLANT PV was able to fabricate efficient CIGS solar cells (8.7%) but could not achieve equivalent performance using AIGS. During the nine-month grant PLANT PV set up a variety of thin film characterization tools (e.g. drive-level capacitance profiling) at the Molecular Foundry, a Department of Energy User Facility, that are now available to both industrial and academic researchers via the grant process. PLANT PV was also able to develop the back end processing of thin film solar cells at Lawrence Berkeley National Labs to achieve 8.7% efficient CIGS solar cells. This processing development will be applied to other types of thin film PV cells at the Lawrence Berkeley National Labs. While PLANT PV was able to study AIGS film growth and optoelectronic properties we concluded that AIGS produced using these methods would have a limited efficiency and would not be commercially feasible. PLANT PV did not apply for the Phase II of this grant.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-06-11

    mixture of solution and physical vapor deposition processing, but these films lacked the p-type doping levels that are required to make decent solar cells. Over the course of the project PLANT PV was able to fabricate efficient CIGS solar cells (8.7%) but could not achieve equivalent performance using AIGS. During the nine-month grant PLANT PV set up a variety of thin film characterization tools (e.g. drive-level capacitance profiling) at the Molecular Foundry, a Department of Energy User Facility, that are now available to both industrial and academic researchers via the grant process. PLANT PV was also able to develop the back end processing of thin film solar cells at Lawrence Berkeley National Labs to achieve 8.7% efficient CIGS solar cells. This processing development will be applied to other types of thin film PV cells at the Lawrence Berkeley National Labs. While PLANT PV was able to study AIGS film growth and optoelectronic properties we concluded that AIGS produced using these methods would have a limited efficiency and would not be commercially feasible. PLANT PV did not apply for the Phase II of this grant.

  7. Polymer tandem solar cells

    NARCIS (Netherlands)

    Hadipour, Afshin

    2007-01-01

    The global demand for energy is expanding continually. Therefore, realization of green power sources are needed since combustion of fossil fuels will have serious consequences for the climate on the Earth. With a photovoltaic device, the solar light can be converted into electricity which is the mos

  8. Effects of surface treatments on high mobility ITiO coated glass substrates for dye sensitized solar cells and their tandem solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Bowers, J.W.; Upadhyaya, H.M. [Centre for Renewable Energy Systems Technology, Department of Electronic and Electrical Engineering, Loughborough University, Leicestershire LE11 3TU (United Kingdom); Nakada, T. [Department of Electrical Engineering and Electronics, Aoyama Gakuin University, Setagaya-ku, Tokyo 157-8572 (Japan); Tiwari, A.N. [Laboratory for Thin Films and Photovoltaics, EMPA (Swiss Federal Laboratories for Material Testing and Research), Ueberlandstrasse 129, CH-8600 Duebendorf (Switzerland)

    2010-04-15

    Dye sensitized solar cells (DSCs) have the potential to be used as a top device in a tandem solar cell structure with a bottom Cu(In,Ga)Se{sub 2} (CIGS) cell. Optical losses, however, within the fluorine doped tin oxide (FTO) conducting electrode used with DSCs limit the light available for the bottom cell for photocurrent generation, and therefore the whole device. High mobility transparent conducting oxides have the potential to reduce these optical losses, since the transmission in the near infrared of these substrates is high compared to standard conducting oxides. Attempts have in the past been made to use these conducting oxide substrates as the electrodes in DSCs; however delamination of the deposited TiO{sub 2} layer and an increase in sheet resistance of the high mobility material have caused problems. Here we present alternative surface treatments to ensure that delamination is significantly reduced, as well as a method to recover lost conductivity of heated indium oxide films, which result in transparent cells of over 7% efficiency, which is close to that reached on standard FTO substrates. (author)

  9. Solar cell is not absolutely ecologically sound

    Energy Technology Data Exchange (ETDEWEB)

    Van Calmthout, M.

    1988-11-01

    The University of Utrecht, Netherlands, inventorized the social costs of a large-scale solar cell industry in particular with regard to the environmental impacts. During production and dismantlement of photovoltaic systems hazardous wastes and dangerous situations can be released respectively can occur. The most important results are discussed. Four solar cell technologies are highlighted: the crystalline silicon solar cell, the amorphous silicon solar cell, the CdS/CuInSe/sub 2/ solar cell, and the GaAs solar cell. 1 fig., 1 tab.

  10. Solar cell circuit and method for manufacturing solar cells

    Science.gov (United States)

    Mardesich, Nick (Inventor)

    2010-01-01

    The invention is a novel manufacturing method for making multi-junction solar cell circuits that addresses current problems associated with such circuits by allowing the formation of integral diodes in the cells and allows for a large number of circuits to readily be placed on a single silicon wafer substrate. The standard Ge wafer used as the base for multi-junction solar cells is replaced with a thinner layer of Ge or a II-V semiconductor material on a silicon/silicon dioxide substrate. This allows high-voltage cells with multiple multi-junction circuits to be manufactured on a single wafer, resulting in less array assembly mass and simplified power management.

  11. Current-Enhanced Quantum Well Solar Cells

    Institute of Scientific and Technical Information of China (English)

    LOU Chao-Gang; SUN Qiang; XU Jun; ZHANG Xiao-Bing; LEI Wei; WANG Bao-Ping; CHEN Wen-Jun; QIAO Zai-Xiang

    2006-01-01

    We present the experimental results that demonstrate the enhancement of the short-circuit current of quantum well solar cells. The spectral response shows that the introduction of quantum wells extends the absorption spectrum of solar cells. The current densities under different truncated spectrums significantly increase, showing that quantum well solar cells are suitable to be the middle cells of GaInP/GaAs/Ge triple-junction solar cells to increase their overall conversion efficiency.

  12. Analysis of CdTe solar cells in relation to materials issues

    International Nuclear Information System (INIS)

    By now, extensive experimental research is available on thin film solar cells based on CdTe and on CIGS, and their electrical and optical behaviour is characterised by a multitude of diverse characterisation techniques. At the same time, numerical simulation programmes have matured and are available to the research community to assist in interpreting these measurements consistently. Once multiple measurements are (more or less) quantitatively described, the numerical simulation can be used to explore the effect of a variation of materials parameter (e.g. the presence or absence of a property, or variation in a range of values) to the final solar cell characteristics. Examples of such analysis for CdTe solar cells are shown. In CdTe cells, much research has been devoted to the activation treatment of the absorber, and to the technology of the back contact. Analysis of ample measurements has evidenced the crucial role of the profile of the (effective) doping density through the device. It will be illustrated how this relative simple (but hardly mastered) materials property has a far reaching influence to the cell characteristics such as roll-over and cross-over of I-V curves, also in dependence on illumination and voltage, conventional and apparent quantum efficiency, and finally fill factor and efficiency

  13. Photon upconversion for thin film solar cells

    NARCIS (Netherlands)

    de Wild, J.

    2012-01-01

    In this research one of the many possible methods to increase the efficiency of solar cells is described. The method investigated is based on adapting the solar light in such a way that the solar cell can convert more light into electricity. The part of the solar spectrum that is adapted is the part

  14. Nanosecond laser-induced selective removal of the active layer of CuInGaSe2 solar cells by stress-assisted ablation

    Science.gov (United States)

    Buzás, András; Geretovszky, Zsolt

    2012-06-01

    We demonstrate that laser pulses of nanosecond duration (λ=1064 nm, τ=25 ns, PRR =5 kHz) are capable of the clean removal of the CuInGaSe2 (CIGS) and ZnO:Al layers in the layer structure of chalcogenide-based solar cells, leaving the underlying Mo layer undamaged and producing excellent crater morphology. Our results prove that the material removal process is governed by the thermomechanical stress developing in the CIGS layer due to rapid laser heating. In the mechanical ablation of the active layer, three phenomena play a crucial role, namely, delamination, buckling, and fracture. Morphological and compositional analysis of the laser-processed areas is used to identify the experimental parameters where clean mechanical ablation can be achieved. Numerical calculations, performed in the comsol software environment, are also presented to complement the experimental tendencies and verify the proposed model. Our calculation proves the development of a stress distribution that drives the delamination of the CIGS and Mo layers. As the delamination front proceeds radially outward, the separation of the layers ceases in the colder outer regions according to the Griffith's criterion and defines the size of the craters produced afterwards. The free-standing chalcogenide layer continues to deform, and buckling results in a growing tensile stress at the perimeter of the delaminated area, where ultimately fracture will finalize the removal process and facilitate the clean ablation of the laser-irradiated area.

  15. An investigation into the effects of band gap and doping concentration on Cu(In,Ga)Se2 solar cell efficiency.

    Science.gov (United States)

    Asaduzzaman, Md; Hasan, Mehedi; Bahar, Ali Newaz

    2016-01-01

    A simulation study of a Cu(In1 - xGax)Se2 (CIGS) thin film solar cell has been carried out with maximum efficiency of 24.27 % (Voc = 0.856 V, Jsc = 33.09 mA/cm(2) and FF = 85.73 %). This optimized efficiency is obtained by determining the optimum band gap of the absorber and varying the doping concentration of constituent layers. The Ga content denoted by x = Ga/(In + Ga) is selected as 0.35 which provides the optimum band gap of absorber layer as 1.21 eV. Theoretically, the effects of Ga fraction "x" on CIGS absorber band gap are investigated and to avoid the lattice mismatch effect, the efficiency measurements due to the CIGS band gaps >1.21 eV have not come to the consideration. A one-dimensional simulator ADEPT/F 2.1 has been used to analyze the fabricated device parameters and hence to calculate open circuit voltage, short circuit current, fill factor and efficiency.

  16. Effects of Mo surface oxidation on Cu(In,Ga)Se2 solar cells fabricated by three-stage process with KF postdeposition treatment

    Science.gov (United States)

    Kamikawa, Yukiko; Nishinaga, Jiro; Ishizuka, Shogo; Shibata, Hajime; Niki, Shigeru

    2016-02-01

    The surface oxidation condition of the Mo back contact on a soda lime glass (SLG) substrate was varied by air annealing and chemical etching. Then, the evolution of a photovoltaic property was studied for Cu(In,Ga)Se2 (CIGS) solar cells grown by a three stage process with KF postdeposition treatment. Upon the removal of the oxidized layer from the Mo surface by chemical etching, the c-axis orientation of MoSe2 tended to be random, whereas the c-axis was perpendicular when the Mo surface was oxidized. An enhancement of the diffusion of Na and K from SLG to CIGS was observed upon removing the molybdenum oxide, which functions as a barrier to alkali-metal diffusion. The varied orientation of MoSe2 can also affect the alkali-metal diffusion kinetics. The open-circuit voltage (VOC) markedly increased after removing the oxidized layer from the Mo surface, mainly as a result of an increase in carrier density in CIGS.

  17. Commercialization of High Efficiency Low Cost CIGS Technology Based on Electroplating: Final Technical Progress Report, 28 September 2007 - 30 June 2009

    Energy Technology Data Exchange (ETDEWEB)

    Basol, B.

    2010-08-01

    This report describes SoloPower's work as a Photovoltaic Technology Incubator awardee within the U.S. Department of Energy's Solar Energy Technologies Program. The term of this subcontract with the National Renewable Energy Laboratory was two years. The project focused on SoloPower's electrodeposition-based copper indium gallium (di)selenide (CIGS) technology. Under this subcontract, SoloPower improved the quality of its flexible metal substrates, increased the size of its solar cells from 0.5 cm2 to 120 cm2, increased the small-area cell efficiencies from near 11% to near 14%, demonstrated large-area cells, and developed a module manufacturing process.

  18. Organic and hybrid solar cells

    CERN Document Server

    Huang, Hui

    2014-01-01

    This book delivers a comprehensive evaluation of organic and hybrid solar cells and identifies their fundamental principles and numerous applications. Great attention is given to the charge transport mechanism, donor and acceptor materials, interfacial materials, alternative electrodes, device engineering and physics, and device stability. The authors provide an industrial perspective on the future of photovoltaic technologies.

  19. Fullerene based organic solar cells

    NARCIS (Netherlands)

    Popescu, Lacramioara Mihaela

    2008-01-01

    The direct conversion of the sunlight into electricity is the most elegant process to generate environmentally-friendly renewable energy. Plastic solar cells offer the prospect of flexible, lightweight, lower cost of manufacturing, and hopefully an efficient way to produce electricity from sunlight.

  20. Solar-Cell Slide Rule

    Science.gov (United States)

    Yamakawa, K. A.

    1983-01-01

    Slide rule relates efficiency, impurity types, impurity concentrations, and process types. Solar cell slide rule calculations are determination of allowable impurity concentration for nonredistributive process, determination of impurity buildup factor for redistributive process and determination of allowable impurity concentration for redistributive process.

  1. Multi-Material Front Contact for 19% Thin Film Solar Cells

    Directory of Open Access Journals (Sweden)

    Joop van Deelen

    2016-02-01

    Full Text Available The trade-off between transmittance and conductivity of the front contact material poses a bottleneck for thin film solar panels. Normally, the front contact material is a metal oxide and the optimal cell configuration and panel efficiency were determined for various band gap materials, representing Cu(In,GaSe2 (CIGS, CdTe and high band gap perovskites. Supplementing the metal oxide with a metallic copper grid improves the performance of the front contact and aims to increase the efficiency. Various front contact designs with and without a metallic finger grid were calculated with a variation of the transparent conductive oxide (TCO sheet resistance, scribing area, cell length, and finger dimensions. In addition, the contact resistance and illumination power were also assessed and the optimal thin film solar panel design was determined. Adding a metallic finger grid on a TCO gives a higher solar cell efficiency and this also enables longer cell lengths. However, contact resistance between the metal and the TCO material can reduce the efficiency benefit somewhat.

  2. Nanowire-based All Oxide Solar Cells

    OpenAIRE

    Yang, Peidong

    2009-01-01

    We present an all-oxide solar cell fabricated from vertically oriented zinc oxide nanowires and cuprous oxide nanoparticles. Our solar cell consists of vertically oriented n-type zinc oxide nanowires, surrounded by a film constructed from p-type cuprous oxide nanoparticles. Our solution-based synthesis of inexpensive and environmentally benign oxide materials in a solar cell would allow for the facile production of large-scale photovoltaic devices. We found that the solar cell performance is ...

  3. Electromagnetic approach to ultrathin solar cell efficiencies

    OpenAIRE

    Niv, A.; Gharghi, M.; Abrams, Z. R.; Gladden, C.; Zhang, X.

    2011-01-01

    Current methods for evaluating solar cell efficiencies cannot be applied to extremely thin cells where phenomena from the realm of near field optics prevail. We overcome this problem by offering a rigorous electromagnetic calculation of solar cell efficiencies based on the fluctuation dissipation theorem. Our approach is demonstrated by calculating the efficiency of a GaAs solar cell with an Au back reflector for thicknesses well below the typical wavelength of the solar flux. It is shown tha...

  4. Perovskite solar cells: an emerging photovoltaic technology

    OpenAIRE

    Nam-Gyu Park

    2015-01-01

    Perovskite solar cells based on organometal halides represent an emerging photovoltaic technology. Perovskite solar cells stem from dye-sensitized solar cells. In a liquid-based dye-sensitized solar cell structure, the adsorption of methylammonium lead halide perovskite on a nanocrystalline TiO2 surface produces a photocurrent with a power conversion efficiency (PCE) of around 3–4%, as first discovered in 2009. The PCE was doubled after 2 years by optimizing the perovskite coating conditions....

  5. Key Physical Mechanisms in Nanostructured Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. Investigation on Silicon Thin Film Solar Cells

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The preparation, current status and trends are investigated for silicon thin film solar cells. The advantages and disadvantages of amorphous silicon thin film, polycrystalline silicon thin film and mono-crystalline silicon thin film solar cells are compared. The future development trends are pointed out. It is found that polycrystalline silicon thin film solar cells will be more promising for application with great potential.

  7. Sheet plastic filters for solar cells

    Science.gov (United States)

    Wizenick, R. J.

    1972-01-01

    Poly(vinylidene fluoride) (PVF) film protects solar cells on Mars surface from radiation and prevents degradation of solar cell surfaces by Martian dust storms. PVF films may replace glass or quartz windows on solar cell arrays used to generate power on earth.

  8. Film adhesion in amorphous silicon solar cells

    Indian Academy of Sciences (India)

    A R M Yusoff; M N Syahrul; K Henkel

    2007-08-01

    A major issue encountered during fabrication of triple junction -Si solar cells on polyimide substrates is the adhesion of the solar cell thin films to the substrates. Here, we present our study of film adhesion in amorphous silicon solar cells made on different polyimide substrates (Kapton VN, Upilex-S and Gouldflex), and the effect of tie coats on film adhesion.

  9. Polymer-based solar cells

    Directory of Open Access Journals (Sweden)

    Alex C. Mayer

    2007-11-01

    Full Text Available A significant fraction of the cost of solar panels comes from the photoactive materials and sophisticated, energy-intensive processing technologies. Recently, it has been shown that the inorganic components can be replaced by semiconducting polymers capable of achieving reasonably high power conversion efficiencies. These polymers are inexpensive to synthesize and can be solution-processed in a roll-to-roll fashion with high throughput. Inherently poor polymer properties, such as low exciton diffusion lengths and low mobilities, can be overcome by nanoscale morphology. We discuss polymer-based solar cells, paying particular attention to device design and potential improvements.

  10. Concentrated sunlight for organic solar cells

    DEFF Research Database (Denmark)

    Tromholt, Thomas

    2010-01-01

    Concentrated sunlight provides a novel approach to the study of the physical and electrical parameters of organic solar cells. The study of performance of organic solar cells at high solar concentrations provides insight into the physics, which cannot be studied with conventional solar simulators...... studies of polymers for organic solar cells. Degradation was monitored by the evolution of the UV-vis absorption over time. Varying the solar intensity from 1 to 200 suns, the degradation rates were increased by more than a factor of 100 relative to degradation at 1 simulated sun. 5 different polymers....... A high solar intensity study of inverted P3HT:PCBM solar cells is presented. Performance peak positions were found to be in the range of 1-5 suns, with smaller cells peaking at higher solar concentrations. Additionally, concentrated sunlight is demonstrated as a practical tool for accelerated stability...

  11. Solution-processed solar cells based on environmentally friendly AgBiS2 nanocrystals

    Science.gov (United States)

    Bernechea, María; Miller, Nichole Cates; Xercavins, Guillem; So, David; Stavrinadis, Alexandros; Konstantatos, Gerasimos

    2016-08-01

    Solution-processed inorganic solar cells are a promising low-cost alternative to first-generation solar cells. Solution processing at low temperatures combined with the use of non-toxic and abundant elements can help minimize fabrication costs and facilitate regulatory acceptance. However, at present, there is no material that exhibits all these features while demonstrating promising efficiencies. Many of the candidates being explored contain toxic elements such as lead or cadmium (perovskites, PbS, CdTe and CdS(Se)) or scarce elements such as tellurium or indium (CdTe and CIGS(Se)/CIS). Others require high-temperature processes such as selenization or sintering, or rely on vacuum deposition techniques (Sb2S(Se)3, SnS and CZTS(Se)). Here, we present AgBiS2 nanocrystals as a non-toxic, earth-abundant material for high-performance, solution-processed solar cells fabricated under ambient conditions at low temperatures (≤100 °C). We demonstrate devices with a certified power conversion efficiency of 6.3%, with no hysteresis and a short-circuit current density of ∼22 mA cm‑2 for an active layer thickness of only ∼35 nm.

  12. Pin solar cells made of amorphous silicon

    Science.gov (United States)

    Plaettner, R. D.; Kruehler, W. W.

    Investigations leading to solar cells with a structure SnO2-pin and an efficiency up to 9.8% are reviewed. The production of large-surface metal/pin/transparent conductive oxide (TCO)-solar cells is discussed. A two-chamber reactor, grid structure and tinning of cells, and an a-Si-module are described. The production of glass/TCO/pin/metal-solar cells and a-SiGe:H-compounds is outlined. Measurements on solar cells and diodes including the efficiency of a-Si:H-solar cells, spectral sensitivity, diffusion lengths, field effect measurements, and modifications of solar cells (space-charge limited currents, reduction of solar cells aging) are treated.

  13. Investigation of Non-Vacuum Deposition Techniques in Fabrication of Chalcogenide-Based Solar Cell Absorbers

    KAUST Repository

    Alsaggaf, Ahmed

    2015-07-01

    The environmental challenges are increasing, and so is the need for renewable energy. For photovoltaic applications, thin film Cu(In,Ga)(S,Se)2 (CIGS) and CuIn(S,Se)2 (CIS) solar cells are attractive with conversion efficiencies of more than 20%. However, the high-efficiency cells are fabricated using vacuum technologies such as sputtering or thermal co-evaporation, which are very costly and unfeasible at industrial level. The fabrication involves the uses of highly toxic gases such as H2Se, adding complexity to the fabrication process. The work described here focused on non-vacuum deposition methods such as printing. Special attention has been given to printing designed in a moving Roll-to-Roll (R2R) fashion. The results show potential of such technology to replace the vacuum processes. Conversion efficiencies for such non-vacuum deposition of Cu(In,Ga)(S,Se)2 solar cells have exceeded 15% using hazardous chemicals such as hydrazine, which is unsuitable for industrial scale up. In an effort to simplify the process, non-toxic suspensions of Cu(In,Ga)S2 molecular-based precursors achieved efficiencies of ~7-15%. Attempts to further simplify the selenization step, deposition of CuIn(S,Se)2 particulate solutions without the Ga doping and non-toxic suspensions of Cu(In,Ga)Se2 quaternary precursors achieved efficiencies (~1-8%). The contribution of this research was to provide a new method to monitor printed structures through spectral-domain optical coherence tomography SD-OCT in a moving fashion simulating R2R process design at speeds up to 1.05 m/min. The research clarified morphological and compositional impacts of Nd:YAG laser heat-treatment on Cu(In,Ga)Se2 absorber layer to simplify the annealing step in non-vacuum environment compatible to R2R. Finally, the research further simplified development methods for CIGS solar cells based on suspensions of quaternary Cu(In,Ga)Se2 precursors and ternary CuInS2 precursors. The methods consisted of post deposition reactive

  14. Hybrid emitter all back contact solar cell

    Energy Technology Data Exchange (ETDEWEB)

    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.

  15. High Efficiency Polymer Solar Cells Technologies

    Institute of Scientific and Technical Information of China (English)

    Abdrhman M G; LI Hang-quan; ZHANG Li-ye; ZHOU Bing

    2006-01-01

    The conjugated polymer-based solar cell is one of the most promising devices in search of sustainable, renewable energy sources in last decade. It is the youngest field in organic solar cell research and also is certainly the fastest growing one at the moment. In addition, the key factor for polymer-based solar cells with high-efficiency is to invent new materials. Organic solar cell has attracted significant researches and commercial interest due to its low cost in fabrication and flexibility in applications. However, they suffer from relatively low conversion efficiency. The summarization of the significance and concept of high efficiency polymer solar cell technologies are presented.

  16. Emitter/absorber interface of CdTe solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Song, Tao [Physics Department, Colorado State University, Fort Collins, Colorado 80523, USA; Kanevce, Ana [National Renewable Energy Laboratory, Golden, Colorado 80401, USA; Sites, James R. [Physics Department, Colorado State University, Fort Collins, Colorado 80523, USA

    2016-06-17

    The performance of CdTe solar cells can be very sensitive to their emitter/absorber interfaces, especially for high-efficiency cells with improved bulk properties. When interface defect states are located at efficient recombination energies, performance losses from acceptor-type interface defects can be significant. Numerical simulations show that the emitter/absorber band alignment, the emitter doping and thickness, and the defect properties of the interface (i.e. defect density, defect type, and defect energy) can all play significant roles in the interface recombination. In particular, a type I heterojunction with small conduction-band offset (0.1 eV cell efficiency in spite of high interface defect density, much like with Cu(In,Ga)Se2 (CIGS) cells. The basic principle is that positive ..delta..EC, often referred to as a 'spike', creates an absorber inversion and hence a large hole barrier adjacent to the interface. As a result, the electron-hole recombination is suppressed due to an insufficient hole supply at the interface. A large spike (..delta..EC >/= 0.4 eV), however, can impede electron transport and lead to a reduction of photocurrent and fill-factor. In contrast to the spike, a 'cliff' (.delta..EC < 0 eV) is likely to allow many holes in the vicinity of the interface, which will assist interface recombination and result in a reduced open-circuit voltage. In addition, a thin and highly-doped emitter can invert the absorber, form a large hole barrier, and decrease device performance losses due to high interface defect density. CdS is the most common emitter material used in CdTe solar cells, but the CdS/CdTe interface is in the cliff category and is not favorable from the band-offset perspective. Other n-type emitter choices, such as (Mg,Zn)O, Cd(S,O), or (Cd,Mg)Te, can be tuned by varying the elemental ratio for an optimal positive value of ..delta..EC. These materials are predicted

  17. Three-Terminal Amorphous Silicon Solar Cells

    Directory of Open Access Journals (Sweden)

    Cheng-Hung Tai

    2011-01-01

    Full Text Available Many defects exist within amorphous silicon since it is not crystalline. This provides recombination centers, thus reducing the efficiency of a typical a-Si solar cell. A new structure is presented in this paper: a three-terminal a-Si solar cell. The new back-to-back p-i-n/n-i-p structure increased the average electric field in a solar cell. A typical a-Si p-i-n solar cell was also simulated for comparison using the same thickness and material parameters. The 0.28 μm-thick three-terminal a-Si solar cell achieved an efficiency of 11.4%, while the efficiency of a typical a-Si p-i-n solar cell was 9.0%. Furthermore, an efficiency of 11.7% was achieved by thickness optimization of the three-terminal solar cell.

  18. Silicon Carbide Solar Cells Investigated

    Science.gov (United States)

    Bailey, Sheila G.; Raffaelle, Ryne P.

    2001-01-01

    The semiconductor silicon carbide (SiC) has long been known for its outstanding resistance to harsh environments (e.g., thermal stability, radiation resistance, and dielectric strength). However, the ability to produce device-quality material is severely limited by the inherent crystalline defects associated with this material and their associated electronic effects. Much progress has been made recently in the understanding and control of these defects and in the improved processing of this material. Because of this work, it may be possible to produce SiC-based solar cells for environments with high temperatures, light intensities, and radiation, such as those experienced by solar probes. Electronics and sensors based on SiC can operate in hostile environments where conventional silicon-based electronics (limited to 350 C) cannot function. Development of this material will enable large performance enhancements and size reductions for a wide variety of systems--such as high-frequency devices, high-power devices, microwave switching devices, and high-temperature electronics. These applications would supply more energy-efficient public electric power distribution and electric vehicles, more powerful microwave electronics for radar and communications, and better sensors and controls for cleaner-burning, more fuel-efficient jet aircraft and automobile engines. The 6H-SiC polytype is a promising wide-bandgap (Eg = 3.0 eV) semiconductor for photovoltaic applications in harsh solar environments that involve high-temperature and high-radiation conditions. The advantages of this material for this application lie in its extremely large breakdown field strength, high thermal conductivity, good electron saturation drift velocity, and stable electrical performance at temperatures as high as 600 C. This behavior makes it an attractive photovoltaic solar cell material for devices that can operate within three solar radii of the Sun.

  19. Rapid thermal annealing effect on Cu(In, Ga)Se2 solar cells%Cu(In,Ga)Se2太阳能电池快速热退火效应

    Institute of Scientific and Technical Information of China (English)

    杨洁; 陈东生; 郑玲玲; 杜汇伟; 周平华; 石建伟; 徐飞; 马忠权

    2012-01-01

    利用光致发光(PL)分析快速热退火对Cu(In,Ga)Se2(CIGS)电池的影响,研究退火对薄膜缺陷的影响.Cu(In,Ga)Se2电池的PL谱中总共有7个峰,即2个可见波段峰和5个红外波段峰.退火温度较低,可减少薄膜体内缺陷,提高载流子浓度,改善薄膜质量;退火温度过高,则会引起正常格点处元素扩散,元素化学计量比改变,体内缺陷增加,吸收层带隙降低,反而会对CIGS薄膜造成破坏.%The paper studies the rapid thermal annealing(RTA) effect on Cu(In> Ga)Se2 (CIGS) solar cells at different annealing temperatures by photoluminescence(PL). Continuous RTA was applied to CIGS solar cells to study annealing effect on film defects. Seven peaks exist in CIGS PL spectra: two in visible light region, the others in infrared region. When the temperature is relatively low, RTA treatment can improve the film quality because of the decrease of defects and the increase of carriers. High temperature RTA treatment will lead to elements diffusion between layers and change of stoichiometric ratio, increasing interface states and decreasing the bandgap of absorber layer, and thus destroy the device structures.

  20. Research on polycrystalline thin-film CuInGaSe{sub 2} solar cells. Annual subcontract report, 3 May 1991--21 May 1993

    Energy Technology Data Exchange (ETDEWEB)

    Chen, W.S.; Stewart, J.M.; Mickelsen, R.A.; Devaney, W.E.; Stanbery, B.J. [Boeing Co., Seattle, WA (United States). Defense and Space Systems Group

    1993-10-01

    This report describes work to fabricate high-efficiency CdZnS/CuInGaSe{sub 2}, thin-film solar cells and to develop improved transparent conductor window layers such as ZnO. The specific technical milestone for Phase I was to demonstrate an air mass (AM) 1.5 global 13% , 1-cm{sup 2} total-area CuInGaSe{sub 2} (CIGS) thin-film solar cell. For Phase II, the objective was to demonstrate an AM1.5 global 13.5%, 1-cm{sup 2} total-area efficiency. We focused our activities on three areas. First, we modified the CIGS deposition system to double its substrate capacity. Second, we developed new tooling to enable investigation of a modified aqueous CdZnS process in which the goal was to improve the yield of this critical step in the device fabrication process. Third, we upgraded the ZnO sputtering system to improve its reliability and reproducibility. A dual rotatable cathode metallic source was installed, and the sputtering parameters were further optimized to improve ZnO`s properties as a transparent conducting oxide (TCO). Combining the refined CdZnS process with CIGS from the newly fixtured deposition system enable us to fabricate and deliver a ZnO/Cd{sub 0.08}Zn{sub 0.20}S/CuIn{sub 0.74}Ga{sub 0.26}Se{sub 2} cell on alumina with I-V characteristics, as measured by NREL under standard test conditions, of 13.7% efficiency with V{proportional_to} = 0.5458 V, J{sub sc} = 35.48 mA/cm{sup 2}, FF = 0.688, and efficiency = 14.6%.

  1. Improved open-circuit voltage in Cu(In,Ga)Se{sub 2} solar cells with high work function transparent electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Jäger, Timo, E-mail: timo.jaeger@empa.ch; Romanyuk, Yaroslav E.; Bissig, Benjamin; Pianezzi, Fabian; Nishiwaki, Shiro; Reinhard, Patrick; Steinhauser, Jérôme; Tiwari, Ayodhya N. [Empa—Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Thin Films and Photovoltaics, Überlandstrasse 129, 8600 Dübendorf (Switzerland); Schwenk, Johannes [Empa—Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Nanoscale Materials Science, Überlandstrasse 129, 8600 Dübendorf (Switzerland)

    2015-06-14

    Hydrogenated indium oxide (IOH) is implemented as transparent front contact in Cu(In,Ga)Se{sub 2} (CIGS) solar cells, leading to an open circuit voltage V{sub OC} enhanced by ∼20 mV as compared to reference devices with ZnO:Al (AZO) electrodes. This effect is reproducible in a wide range of contact sheet resistances corresponding to various IOH thicknesses. We present the detailed electrical characterization of glass/Mo/CIGS/CdS/intrinsic ZnO (i-ZnO)/transparent conductive oxide (TCO) with different IOH/AZO ratios in the front TCO contact in order to identify possible reasons for the enhanced V{sub OC}. Temperature and illumination intensity-dependent current-voltage measurements indicate that the dominant recombination path does not change when AZO is replaced by IOH, and it is mainly limited to recombination in the space charge region and at the junction interface of the solar cell. The main finding is that the introduction of even a 5 nm-thin IOH layer at the i-ZnO/TCO interface already results in a step-like increase in V{sub OC}. Two possible explanations are proposed and verified by one-dimensional simulations using the SCAPS software. First, a higher work function of IOH as compared to AZO is simulated to yield an V{sub OC} increase by 21 mV. Second, a lower defect density in the i-ZnO layer as a result of the reduced sputter damage during milder sputter-deposition of IOH can also add to a maximum enhanced V{sub OC} of 25 mV. Our results demonstrate that the proper choice of the front TCO contact can reduce the parasitic recombination and boost the efficiency of CIGS cells with improved corrosion stability.

  2. Recent Advances in Solar Cell Technology

    Science.gov (United States)

    Landis, Geoffrey A.; Bailey, Sheila G.; Piszczor, Michael F., Jr.

    1996-01-01

    The advances in solar cell efficiency, radiation tolerance, and cost over the last decade are reviewed. Potential performance of thin-film solar cells in space are discussed, and the cost and the historical trends in production capability of the photovoltaics industry are considered with respect to the requirements of space power systems. Concentrator cells with conversion efficiency over 30%, and nonconcentrating solar cells with efficiency over 25% are now available, and advanced radiation-tolerant cells and lightweight, thin-film arrays are both being developed. Nonsolar applications of solar cells, including thermophotovoltaics, alpha- and betavoltaics, and laser power receivers, are also discussed.

  3. CIBS Solar Cell Development Final Scientific/Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Exstrom, Christopher L.; Soukup, Rodney J.; Ianno, Natale J.

    2011-09-28

    Efforts to fabricate and study a new photovoltaic material, copper indium boron diselenide (CuInxB1-xSe2 or CIBS), were undertaken. Attempts to prepare CIBS using sputtering deposition techniques resulted in segregation of boron from the rest of elements in the material. CIBS nanocrystals were prepared from the reaction of elemental Se with CuCl, InCl3, and boric acid in solution, but the product material quickly decomposed upon heating that was required in attempts to convert the nanocrystals into a thin film. The investigation of the reasons for the lack of CIBS material stability led to new structure-property studies of closely-related photovoltaic systems as well as studies of new solar cell materials and processing methods that could enhance the development of next-generation solar technologies. A detailed compositional study of CuIn1-xAlxSe2 (CIAS, a system closely related to CIBS) revealed a non-linear correlation between crystal lattice size and the Al/(In+Al) ratios with dual-phase formation being observed. A new nanocrystal-to-thin-film processing method was developed for the preparation of CuIn1-xGaxSe2 (CIGS) thin films in which colloidal Se particles are sprayed in contact with CuIn1-xGaxS2 nanoparticles and heated in an argon atmosphere with no other Se source in the system. The process is non-vacuum and does not require toxic gases such as Se vapor or H2Se. Expertise gained from these studies was applied to new research in the preparation of thin-film pyrite FeS2, an attractive earth-abundant candidate material for next-generation photovoltaics. Three methods successfully produced pure pyrite FeS2 films: sulfurization of sputtered Fe films, chemical bath deposition, and sulfurization of Fe2O3 sol-gel precursors. The last method produced pinhole-free films that may be viable for device development. Nickel, platinum, and possibly carbon would appear to serve as good ohmic contact materials. While CdS has a reasonable conduction band energy match to

  4. Work Station For Inverting Solar Cells

    Science.gov (United States)

    Feder, H.; Frasch, W.

    1982-01-01

    Final work station along walking-beam conveyor of solar-array assembly line turns each pretabbed solar cell over, depositing it back-side-up onto landing pad, which centers cell without engaging collector surface. Solar cell arrives at inverting work station collector-side-up with two interconnect tabs attached to collector side. Cells are inverted so that second soldering operation takes place in plain view of operator. Inversion protects collector from damage when handled at later stages of assembly.

  5. Supramolecular photochemistry and solar cells

    Directory of Open Access Journals (Sweden)

    IHA NEYDE YUKIE MURAKAMI

    2000-01-01

    Full Text Available Supramolecular photochemistry as well as solar cells are fascinating topics of current interest in Inorganic Photochemistry and very active research fields which have attracted wide attention in last two decades. A brief outline of the investigations in these fields carried out in our Laboratory of Inorganic Photochemistry and Energy Conversion is given here with no attempt of an exhaustive coverage of the literature. The emphasis is placed on recent work and information on the above mentioned subjects. Three types of supramolecular systems have been the focus of this work: (i cage-type coordination compounds; (ii second-sphere coordination compounds, exemplified by ion-pair photochemistry of cobalt complexes and (iii covalently-linked systems. In the latter, modulation of the photoluminescence and photochemistry of some rhenium complexes are discussed. Solar energy conversion and development of thin-layer photoelectrochemical solar cells based on sensitization of nanocrystalline semiconductor films by some ruthenium polypyridyl complexes are presented as an important application that resulted from specifically engineered artificial assemblies.

  6. Semiconductor materials for solar photovoltaic cells

    CERN Document Server

    Wong-Ng, Winnie; Bhattacharya, Raghu

    2016-01-01

    This book reviews the current status of semiconductor materials for conversion of sunlight to electricity, and highlights advances in both basic science and manufacturing.  Photovoltaic (PV) solar electric technology will be a significant contributor to world energy supplies when reliable, efficient PV power products are manufactured in large volumes at low cost.  Expert chapters cover the full range of semiconductor materials for solar-to-electricity conversion, from crystalline silicon and amorphous silicon to cadmium telluride, copper indium gallium sulfide selenides, dye sensitized solar cells, organic solar cells, and environmentally friendly copper zinc tin sulfide selenides. The latest methods for synthesis and characterization of solar cell materials are described, together with techniques for measuring solar cell efficiency. Semiconductor Materials for Solar Photovoltaic Cells presents the current state of the art as well as key details about future strategies to increase the efficiency and reduce ...

  7. Energy Conversion: Nano Solar Cell

    Science.gov (United States)

    Yahaya, Muhammad; Yap, Chi Chin; Mat Salleh, Muhamad

    2009-09-01

    Problems of fossil-fuel-induced climate change have sparked a demand for sustainable energy supply for all sectors of economy. Most laboratories continue to search for new materials and new technique to generate clean energy at affordable cost. Nanotechnology can play a major role in solving the energy problem. The prospect for solar energy using Si-based technology is not encouraging. Si photovoltaics can produce electricity at 20-30 c//kWhr with about 25% efficiency. Nanoparticles have a strong capacity to absorb light and generate more electrons for current as discovered in the recent work of organic and dye-sensitized cell. Using cheap preparation technique such as screen-printing and self-assembly growth, organic cells shows a strong potential for commercialization. Thin Films research group at National University Malaysia has been actively involved in these areas, and in this seminar, we will present a review works on nanomaterials for solar cells and particularly on hybrid organic solar cell based on ZnO nanorod arrays. The organic layer consisting of poly[2-methoxy-5-(2-ethylhexyloxy)-1, 4-phenylenevinylene] (MEHPPV) and [6, 6]-phenyl C61-butyric acid 3-ethylthiophene ester (PCBE) was spin-coated on ZnO nanorod arrays. ZnO nanorod arrays were grown on FTO glass substrates which were pre-coated with ZnO nanoparticles using a low temperature chemical solution method. A gold electrode was used as the top contact. The device gave a short circuit current density of 2.49×10-4 mA/cm2 and an open circuit voltage of 0.45 V under illumination of a projector halogen light at 100 mW/cm2.

  8. Solar Energy Cell with Rare Earth Film

    Institute of Scientific and Technical Information of China (English)

    Li Baojun; Yang Tao; Zhou Yao; Zhou Meng; Fu Xiliang; Fu Li

    2004-01-01

    The characteristic of the solar energy cell with the rare earth film according to theory of molecular structure was introduced.When sunlight shines, the molecules of the rare earth film can absorb energy of the photon and jump to the excited state from the basic state, and play a role in storing solar energy.When sunlight do not shine, the electron of the excited state returns to the basic state, the rare earth film can automatically give out light and shine to surface of the solar cell, which can make solar cell continuously generate electric current.The rare earth film can absorb direct,scattering sunlight, and increase density of solar energy to reach surface of the solar cell, and play focusing function.The rare earth film can bear 350 ~ 500 ℃, which make the solar cell be able to utilize the focusing function system.Because after luminescence of the rare earth film, it can release again the absorbed solar energy through 1 ~ 8 h, and play a role in storing solar energy; The solar cell with the rare-earth film can generate electricity during night and cloudy days, and remarkably increase efficiency of the solar cell.

  9. Alternative window schemes for CuInSe{sub 2}-based solar cells. Annual report, 1 November 1995--31 October 1996

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, L.C. [Washington State Univ., Richland, WA (United States). Electronic Materials Lab.

    1997-10-01

    The objectives of this program are to develop alternate heterojunction partner layers (buffer layers) for high efficiency CuInSe{sub 2}-based thin-film solar cells, and improve the understanding of how these layers and the details of processing affect cell performance. Investigations have primarily involved three tasks: (1) MOCVD growth of non-cadmium containing buffer layers; (2) optimized processing of buffer layers for high efficiency solar cells; and (3) electrical and physical characterization of layers and devices. Investigations of alternative buffer layers emphasized studies of ZnO grown by MOCVD. Using CIS substrates obtained form Siemens for process development, it was determined that growth procedures that resulted in good results with Siemens CIS (non-sulfur containing material) substrates also worked well with NREL CIGS material. A two step process was developed for growing highly resistive ZnO buffer layers (i-ZnO). In particular, after growing 100 to 150 {angstrom} of ZnO at 250 C, an additional 600 {angstrom} to 800 {angstrom} were grown at 100 C. Collaboration with NREL resulted in a n-ZnO/i-ZnO/CIGS cell which was determined to have a total area efficiency of 12.7%, and an active area efficiency greater than 13%. After growing i-ZnO with the two-step process onto NREL CIGS material, the i-ZnO/CIGS film structure was sent to NREL for deposition of a TCO, namely, conducting ZnO (n-ZnO). Collector grids and a MgF{sub 2} AR coating were also deposited at NREL. Low level efforts were devoted to studies of ZnSe and InSe buffer layers. A total area efficiency of 9.5% was achieved for a completed ZnSe/CIS cell making use of a RF sputtered ZnO for a TCO. Investigations of In{sub x}Se{sub y} (InSe) buffer layers were also initiated this past year.

  10. Solution-deposited CIGS thin films for ultra-low-cost photovoltaics

    Science.gov (United States)

    Eldada, Louay A.; Hersh, Peter; Stanbery, Billy J.

    2010-09-01

    We describe the production of photovoltaic modules with high-quality large-grain copper indium gallium selenide (CIGS) thin films obtained with the unique combination of low-cost ink-based precursors and a reactive transfer printing method. The proprietary metal-organic inks contain a variety of soluble Cu-, In- and Ga- multinary selenide materials; they are called metal-organic decomposition (MOD) precursors, as they are designed to decompose into the desired precursors. Reactive transfer is a two-stage process that produces CIGS through the chemical reaction between two separate precursor films, one deposited on the substrate and the other on a printing plate in the first stage. In the second stage, these precursors are rapidly reacted together under pressure in the presence of heat. The use of two independent thin films provides the benefits of independent composition and flexible deposition technique optimization, and eliminates pre-reaction prior to the synthesis of CIGS. In a few minutes, the process produces high quality CIGS films, with large grains on the order of several microns, and preferred crystallographic orientation, as confirmed by compositional and structural analysis by XRF, SIMS, SEM and XRD. Cell efficiencies of 14% and module efficiencies of 12% were achieved using this method. The atmospheric deposition processes include slot die extrusion coating, ultrasonic atomization spraying, pneumatic atomization spraying, inkjet printing, direct writing, and screen printing, and provide low capital equipment cost, low thermal budget, and high throughput.

  11. Nanostructured Interfaces in Hybrid Solar Cells

    OpenAIRE

    Weickert, Jonas

    2014-01-01

    Excitonic solar cells are an emerging technology which holds the great promise of generating clean and sustainable photovoltaic power at lower cost than conventional silicon solar cells. In excitonic solar cells, the light is absorbed by organic semiconductors and dye molecules, which typically exhibit higher exciton binding energies than inorganic semiconductors. Therefore, free charge carriers can be generated only at interfaces between donor and acceptor materials. These interfaces can pro...

  12. Including excitons in semiconductor solar cell modelling

    OpenAIRE

    Burgelman, Marc; Minnaert, Ben

    2005-01-01

    Excitons are marginally important in classical semiconductor device physics, and their treatment is not included in standard solar cell modelling. However, in organic semiconductors and solar cells, the role of excitons is essential, as the primary effect of light absorption is exciton generation, and free electrons and holes are created by exciton dissociation. First steps to include excitons in solar cell modelling were presented by Green 1996 and Zhang 1998. Their model was restricted to a...

  13. Bypass diode for a solar cell

    Science.gov (United States)

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

    2012-03-13

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

  14. Device operation of organic tandem solar cells

    NARCIS (Netherlands)

    Hadipour, A.; de Boer, B.; Blom, P. W. M.

    2008-01-01

    A generalized methodology is developed to obtain the current-voltage characteristic of polymer tandem solar cells by knowing the electrical performance of both sub cells. We demonstrate that the electrical characteristics of polymer tandem solar cells are correctly predicted for both the series and

  15. Solar Cells Using Quantum Funnels

    KAUST Repository

    Kramer, Illan J.

    2011-09-14

    Colloidal quantum dots offer broad tuning of semiconductor bandstructure via the quantum size effect. Devices involving a sequence of layers comprised of quantum dots selected to have different diameters, and therefore bandgaps, offer the possibility of funneling energy toward an acceptor. Here we report a quantum funnel that efficiently conveys photoelectrons from their point of generation toward an intended electron acceptor. Using this concept we build a solar cell that benefits from enhanced fill factor as a result of this quantum funnel. This concept addresses limitations on transport in soft condensed matter systems and leverages their advantages in large-area optoelectronic devices and systems. © 2011 American Chemical Society.

  16. Three-Terminal Amorphous Silicon Solar Cells

    OpenAIRE

    Cheng-Hung Tai; Chu-Hsuan Lin; Chih-Ming Wang; Chun-Chieh Lin

    2011-01-01

    Many defects exist within amorphous silicon since it is not crystalline. This provides recombination centers, thus reducing the efficiency of a typical a-Si solar cell. A new structure is presented in this paper: a three-terminal a-Si solar cell. The new back-to-back p-i-n/n-i-p structure increased the average electric field in a solar cell. A typical a-Si p-i-n solar cell was also simulated for comparison using the same thickness and material parameters. The 0.28 μm-thick three-terminal a-Si...

  17. Bismuth-doped Cu(In,Ga)Se{sub 2} absorber prepared by multi-layer precursor method and its solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Chantana, Jakapan; Hironiwa, Daisuke; Minemoto, Takashi [Department of Electrical and Electronic Engineering, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga 525-8577 (Japan); Watanabe, Taichi; Teraji, Seiki; Kawamura, Kazunori [Environment and Energy Research Center, Nitto Denko Corporation, 2-8 Yamadaoka, Suita, Osaka 565-0871 (Japan)

    2015-06-15

    Bismuth (Bi)-doped Cu(In,Ga)Se{sub 2} (CIGS) films were prepared by the so-called ''multi-layer precursor method'', obtained by depositing them onto Bi layers with various thicknesses on Mo-coated soda-lime glass (SLG) substrates. Material composition (Cu, In, Ga, and Se) profiles of the CIGS films are almost identical, whereas sodium (Na) is reduced, when Bi thickness is increased. Moreover, the incorporation of Bi into the CIGS film is enhanced with thicker Bi layer. With Bi thickness from 0 to 70 nm, the 2.4-μm-thick CIGS absorbers demonstrate the increase in CIGS grain size, carrier lifetime, and carrier concentration, thus improving their cell performances, especially open-circuit voltage (V{sub OC}). With further increase in Bi thickness of above 70 nm, the CIGS films show the deterioration of CIGS film quality owing to the formation of Bi compounds such as Bi, BiSe, and Bi{sub 4}Se{sub 3}. Consequently, Bi-doped CIGS absorber with thickness of 2.4 μm, prepared with the 70-nm-thick Bi layer on Mo-coated SLG substrate, gives rise to the improvement of photovoltaic performances, especially V{sub OC}. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Thickness Effect of Al-Doped ZnO Window Layer on Damp Heat Stability of CuInGaSe2 Solar Cells: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Pern, F. J.; Mansfield, L.; DeHart, C.; Glick, S. H.; Yan, F.; Noufi, R.

    2011-07-01

    We investigated the damp heat (DH) stability of CuInGaSe2 (CIGS) solar cells as a function of thickness of the Al-doped ZnO (AZO) window layer from the 'standard' 0.12 μm to a modest 0.50 μm over an underlying 0.10-μm intrinsic ZnO buffer layer. The CIGS cells were prepared with external electrical contact using fine Au wire to the tiny 'standard' Ni/Al (0.05 μm/3 μm) metal grid contact pads. Bare cell coupons and sample sets encapsulated in a specially designed, Al-frame test structure with an opening for moisture ingress control using a TPT backsheet were exposed to DH at 85oC and 85% relative humidity, and characterized by current-voltage (I-V), quantum efficiency (QE), and (electrochemical) impedance spectroscopy (ECIS). The results show that bare cells exhibited rapid degradation within 50-100 h, accompanied by film wrinkling and delamination and corrosion of Mo and AlNi grid, regardless of AZO thickness. In contrast, the encapsulated cells did not show film wrinkling, delamination, and Mo corrosion after 168 h DH exposure; but the trend of efficiency degradation rate showed a weak correlation to the AZO thickness.

  19. Integration of Solar Cells on Top of CMOS Chips Part I: a-Si Solar Cells

    NARCIS (Netherlands)

    Lu, Jiwu; Kovalgin, Alexey Y.; Werf, van der Karine H.M.; Schropp, Ruud E.I.; Schmitz, Jurriaan

    2011-01-01

    We present the monolithic integration of deepsubmicrometer complementary metal–oxide–semiconductor (CMOS) microchips with a-Si:H solar cells. Solar cells are manufactured directly on the CMOS chips. The microchips maintain comparable electronic performance, and the solar cells show efficiency values

  20. Morphology of polymer solar cells

    DEFF Research Database (Denmark)

    Böttiger, Arvid P.L.

    of making the transition from the laboratory into the commercial market. One of the biggest challenges in this process is upscaling the production. The object of this thesis is to investigate the morphology of OPV devices produced from pilot scale roll to roll (R2R) coaters. OPV devices still struggle...... with low performance, and the morphology is known to have a critical impact on the performance of a device. Several studies have tried to identify the optimal morphology of OPV devices and how to achieve it. Most work has been focused on OPVs produced by spin coating in a small laboratory scale. Devices...... the morphology of the active layer of the solar cells when produced with water based inks using R2R coating. Using a broad range of scattering and imaging techniques, cells coated with water based inks were investigated, and compared to their spin coated counterpart. Two challenges to be addressed were small...

  1. Progress in Thin Film Solar Cells Based on Cu2ZnSnS4

    Directory of Open Access Journals (Sweden)

    Hongxia Wang

    2011-01-01

    Full Text Available The research in thin film solar cells has been dominated by light absorber materials based on CdTe and Cu(In,GaSe2 (CIGS in the last several decades. The concerns of environment impact of cadmium and the limited availability of indium in those materials have driven the research towards developing new substitute light absorbers made from earth abundant, environment benign materials. Cu2ZnSnS4 (CZTS semiconductor material has emerged as one of the most promising candidates for this aim and has attracted considerable interest recently. Significant progress in this relatively new research area has been achieved in the last three years. Over 130 papers on CZTS have been published since 2007, and the majority of them are on the preparation of CZTS thin films by different methods. This paper, will review the wide range of techniques that have been used to deposit CZTS semiconductor thin films. The performance of the thin film solar cells using the CZTS material will also be discussed.

  2. 7 CFR 1466.27 - Conservation Innovation Grants (CIG).

    Science.gov (United States)

    2010-01-01

    ... PROGRAM Contracts and Payments § 1466.27 Conservation Innovation Grants (CIG). (a) Definitions. In addition to the terms defined in § 1466.3 of this part, the following definitions shall be applicable to... 7 Agriculture 10 2010-01-01 2010-01-01 false Conservation Innovation Grants (CIG). 1466.27...

  3. Organic Tandem Solar Cells: Design and Formation

    Science.gov (United States)

    Chen, Chun-Chao

    In the past decade, research on organic solar cells has gone through an important development stage leading to major enhancements in power conversion efficiency, from 4% to 9% in single-junction devices. During this period, there are many novel processing techniques and device designs that have been proposed and adapted in organic solar-cell devices. One well-known device architecture that helps maximize the solar cell efficiency is the multi-junction tandem solar-cell design. Given this design, multiple photoactive absorbers as subcells are stacked in a monolithic fashion and assembled via series connection into one complete device, known as the tandem solar cell. Since multiple absorbers with different optical energy bandgaps are being applied in one tandem solar-cell device, the corresponding solar cell efficiency is maximized through expanded absorption spectrum and reduced carrier thermalization loss. In Chapter 3, the architecture of solution-processible, visibly transparent solar cells is introduced. Unlike conventional organic solar-cell devices with opaque electrodes (such as silver, aluminum, gold and etc.), the semi-transparent solar cells rely on highly transparent electrodes and visibly transparent photoactive absorbers. Given these two criteria, we first demonstrated the visibly transparent single-junction solar cells via the polymer absorber with near-infrared absorption and the top electrode based on solution-processible silver nanowire conductor. The highest visible transparency (400 ˜ 700 nm) of 65% was achieved for the complete device structure. More importantly, power conversion efficiency of 4% was also demonstrated. In Chapter 4, we stacked two semi-transparent photoactive absorbers in the tandem architecture in order to realize the semi-transparent tandem solar cells. A noticeable performance improvement from 4% to 7% was observed. More importantly, we modified the interconnecting layers with the incorporation of a thin conjugated

  4. Thin-Film CIGS Photovoltaic Technology: Annual Technical Report-Phase II, 16 April 1999-15 April 2000

    Energy Technology Data Exchange (ETDEWEB)

    Delahoy, A.E.; Bruns, J.; Ruppert, A.; Akhtar, M.; Chen, L.; Kiss, Z.J.

    2000-08-24

    A summary of Energy Photovoltaics' Phase II work includes the following: (1) EPV has demonstrated that it can sputter a Mo back-contact capable of supporting very high efficiency cell processing. Using EPV Mo, NREL has deposited a 17.1% CIGS cell (no AR coating). EPV believes it can identify the signature of ``good'' Mo. The Mo was produced on EPV's 0.43 m{sup 2} pilot-line equipment; (2) EPV has performed compound synthesis for several classes of materials, namely non-Cu precursor materials, Cu-containing materials, and ternary buffer materials. Using a ternary compound synthesized at EPV (ZIS) as an evaporation source material for the buffer layer, a Cd-free CIGS device has been produced having an efficiency of 11.5% (560 mV, 32.1 mA/cm{sup 2}, FF 64.3%). The ZIS films are photoconductive, and the devices exhibit no dark-light crossover or light soaking effects; (3) EPV initiated the interest of the University of Oregon in capacitance spectroscopy of CIGS devices. An Urbach tail with characteristic energy E0 < 20meV was identified by transient photocapacitance spectroscopy; (4) Small-area CIGS devices were produced in the pilot-line system with an efficiency of 12.0% (581 mV, 30.1 mA/cm{sup 2}, FF 68.7%), and in an R and D-scale system with 13.3% efficiency (569 mV, 34.1 mA/cm{sup 2}, FF 68.1%); (5) An improved linear evaporation source for Cu delivery has been developed and was used for CIGS formation in the pilot-line system. The deposition width is 45 cm. This technological ``tour de force'' allows EPV to build large-area CIGS systems possessing considerable flexibility. In particular, both EPV's FORNAX process and NREL's 3-stage process have been implemented on the pilot line. A CIGS thickness uniformity of 7% over a 40 cm width has been achieved; (6) A 4-head linear source assembly was designed, constructed, and is in use. Flux monitoring is practiced; (7) Large-area CIGS modules were produced with Voc's up to 36

  5. Perovskite solar cells: an emerging photovoltaic technology

    Directory of Open Access Journals (Sweden)

    Nam-Gyu Park

    2015-03-01

    Full Text Available Perovskite solar cells based on organometal halides represent an emerging photovoltaic technology. Perovskite solar cells stem from dye-sensitized solar cells. In a liquid-based dye-sensitized solar cell structure, the adsorption of methylammonium lead halide perovskite on a nanocrystalline TiO2 surface produces a photocurrent with a power conversion efficiency (PCE of around 3–4%, as first discovered in 2009. The PCE was doubled after 2 years by optimizing the perovskite coating conditions. However, the liquid-based perovskite solar cell receives little attention because of its stability issues, including instant dissolution of the perovskite in a liquid electrolyte. A long-term, stable, and high efficiency (∼10% perovskite solar cell was developed in 2012 by substituting the solid hole conductor with a liquid electrolyte. Efficiencies have quickly risen to 18% in just 2 years. Since PCE values over 20% are realistically anticipated with the use of cheap organometal halide perovskite materials, perovskite solar cells are a promising photovoltaic technology. In this review, the opto-electronic properties of perovskite materials and recent progresses in perovskite solar cells are described. In addition, comments on the issues to current and future challenges are mentioned.

  6. Infrared-Controlled Welding of Solar Cells

    Science.gov (United States)

    Paulson, R.; Finnell, S. E.; Decker, H. J.; Hodor, J. R.

    1982-01-01

    Proposed apparatus for welding large arrays of solar cells to flexible circuit substrates would sense infrared emission from welding spot. Emission would provide feedback for control of welding heat. Welding platform containing optical fibers moves upward through slots in movable holding fixture to contact solar cells. Fibers pick up infrared radiation from weld area.

  7. Screen Printed Metallization of Silicon Solar Cells

    OpenAIRE

    Govaerts, R.; Van Overstraeten, R.; Mertens, R.; Ph. Lauwers; Frisson, L.

    1980-01-01

    This paper presents a screen printing process for the metallization of silicon solar cells. The physics and construction of a classical solar cell are reviewed. The results obtained with a screen printing process are comparable with other, more expensive technologies. This technology does not introduce an additional contact resistance on silicon. The process optimization and the influence of different parameters are discussed.

  8. Towards upconversion for amorphous silicon solar cells

    NARCIS (Netherlands)

    de Wild, J.; Meijerink, A.; Rath, J.K.; van Sark, W.G.J.H.M.; Schropp, R.E.I.

    2010-01-01

    Upconversion of subbandgap light of thin film single junction amorphous silicon solar cells may enhance their performance in the near infrared (NIR). In this paper we report on the application of the NIR–vis upconverter β-NaYF4:Yb3+(18%) Er3+(2%) at the back of an amorphous silicon solar cell in com

  9. Scaling up ITO-Free solar cells

    NARCIS (Netherlands)

    Galagan, Y.O.; Coenen, E.W.C.; Zimmermann, B.; Slooff, L.H.; Verhees, W.J.H.; Veenstra, S.C.; Kroon, J.M.; Jørgensen, M.; Krebs, F.C.; Andriessen, H.A.J.M.

    2014-01-01

    Indium-tin-oxide-free (ITO-free) polymer solar cells with composite electrodes containing current-collecting grids and a semitransparent poly(3,4-ethylenedioxythiophene):polystyrenesulfonate) (PEDOT:PSS) conductor are demonstrated. The up-scaling of the length of the solar cell from 1 to 6 cm and th

  10. Perovskite solar cells: Different facets of performance

    Science.gov (United States)

    Eperon, Giles E.; Ginger, David S.

    2016-08-01

    The electronic properties of halide perovskites vary significantly between crystalline grains, but the impact of this heterogeneity on solar cell performance is unclear. Now, this variability is shown to limit the photovoltaic properties of solar cells, and its origins are linked to differing properties between crystal facets.

  11. Fullerene surfactants and their use in polymer solar cells

    Science.gov (United States)

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

    2015-12-15

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

  12. Methodologies for high efficiency perovskite solar cells

    Science.gov (United States)

    Park, Nam-Gyu

    2016-06-01

    Since the report on long-term durable solid-state perovskite solar cell in 2012, perovskite solar cells based on lead halide perovskites having organic cations such as methylammonium CH3NH3PbI3 or formamidinium HC(NH2)2PbI3 have received great attention because of superb photovoltaic performance with power conversion efficiency exceeding 22 %. In this review, emergence of perovskite solar cell is briefly introduced. Since understanding fundamentals of light absorbers is directly related to their photovoltaic performance, opto-electronic properties of organo lead halide perovskites are investigated in order to provide insight into design of higher efficiency perovskite solar cells. Since the conversion efficiency of perovskite solar cell is found to depend significantly on perovskite film quality, methodologies for fabricating high quality perovskite films are particularly emphasized, including various solution-processes and vacuum deposition method.

  13. Nanowire-based All Oxide Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Yang*, Benjamin D. Yuhas and Peidong; Yang, Peidong

    2008-12-07

    We present an all-oxide solar cell fabricated from vertically oriented zinc oxide nanowires and cuprous oxide nanoparticles. Our solar cell consists of vertically oriented n-type zinc oxide nanowires, surrounded by a film constructed from p-type cuprous oxide nanoparticles. Our solution-based synthesis of inexpensive and environmentally benign oxide materials in a solar cell would allow for the facile production of large-scale photovoltaic devices. We found that the solar cell performance is enhanced with the addition of an intermediate oxide insulating layer between the nanowires and the nanoparticles. This observation of the important dependence of the shunt resistance on the photovoltaic performance is widely applicable to any nanowire solar cell constructed with the nanowire array in direct contact with one electrode.

  14. High Radiation Resistance IMM Solar Cell

    Science.gov (United States)

    Pan, Noren

    2015-01-01

    Due to high launch costs, weight reduction is a key driver for the development of new solar cell technologies suitable for space applications. This project is developing a unique triple-junction inverted metamorphic multijunction (IMM) technology that enables the manufacture of very lightweight, low-cost InGaAsP-based multijunction solar cells. This IMM technology consists of indium (In) and phosphorous (P) solar cell active materials, which are designed to improve the radiation-resistant properties of the triple-junction solar cell while maintaining high efficiency. The intrinsic radiation hardness of InP materials makes them of great interest for building solar cells suitable for deployment in harsh radiation environments, such as medium Earth orbit and missions to the outer planets. NASA Glenn's recently developed epitaxial lift-off (ELO) process also will be applied to this new structure, which will enable the fabrication of the IMM structure without the substrate.

  15. Coating Processes Boost Performance of Solar Cells

    Science.gov (United States)

    2012-01-01

    NASA currently has spacecraft orbiting Mercury (MESSENGER), imaging the asteroid Vesta (Dawn), roaming the red plains of Mars (the Opportunity rover), and providing a laboratory for humans to advance scientific research in space (the International Space Station, or ISS). The heart of the technology that powers those missions and many others can be held in the palm of your hand - the solar cell. Solar, or photovoltaic (PV), cells are what make up the panels and arrays that draw on the Sun s light to generate electricity for everything from the Hubble Space Telescope s imaging equipment to the life support systems for the ISS. To enable NASA spacecraft to utilize the Sun s energy for exploring destinations as distant as Jupiter, the Agency has invested significant research into improving solar cell design and efficiency. Glenn Research Center has been a national leader in advancing PV technology. The Center s Photovoltaic and Power Technologies Branch has conducted numerous experiments aimed at developing lighter, more efficient solar cells that are less expensive to manufacture. Initiatives like the Forward Technology Solar Cell Experiments I and II in which PV cells developed by NASA and private industry were mounted outside the ISS have tested how various solar technologies perform in the harsh conditions of space. While NASA seeks to improve solar cells for space applications, the results are returning to Earth to benefit the solar energy industry.

  16. Industrial n-type solar cells with >20% cell efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Romijn, I.G.; Anker, J.; Burgers, A.R.; Gutjahr, A.; Koppes, M.; Kossen, E.J.; Lamers, M.W.P.E.; Heurtault, Benoit; Saynova-Oosterling, D.S.; Tool, C.J.J. [ECN Solar Energy, Petten (Netherlands)

    2013-03-15

    To realize high efficiencies at low costs, ECN has developed the n-Pasha solar cell concept. The n-Pasha cell concept is a bifacial solar cell concept on n-Cz base material, with which average efficiencies of above 20% have been demonstrated. In this paper recent developments at ECN to improve the cost of ownership (lower Euro/Wp) of the n-Pasha cell concept are discussed. Two main drivers for the manufacturing costs of n-type solar cells are addressed: the n-type Cz silicon material and the silver consumption. We show that a large resistivity range between 2 and 8 cm can be tolerated for high cell efficiency, and that the costs due to the silver metallization can be significantly reduced while increasing the solar cell efficiency. Combining the improved efficiency and cost reduction makes the n-Pasha cell concept a very cost effective solution to manufacture high efficient solar cells and modules.

  17. Tandem photovoltaic solar cells and increased solar energy conversion efficiency

    Science.gov (United States)

    Loferski, J. J.

    1976-01-01

    Tandem photovoltaic cells, as proposed by Jackson (1955) to increase the efficiency of solar energy conversion, involve the construction of a system of stacked p/n homojunction photovoltaic cells composed of different semiconductors. It had been pointed out by critics, however, that the total power which could be extracted from the cells in the stack placed side by side was substantially greater than the power obtained from the stacked cells. A reexamination of the tandem cell concept in view of the development of the past few years is conducted. It is concluded that the use of tandem cell systems in flat plate collectors, as originally envisioned by Jackson, may yet become feasible as a result of the development of economically acceptable solar cells for large scale terrestrial power generation.

  18. Amorphous silicon crystalline silicon heterojunction solar cells

    CERN Document Server

    Fahrner, Wolfgang Rainer

    2013-01-01

    Amorphous Silicon/Crystalline Silicon Solar Cells deals with some typical properties of heterojunction solar cells, such as their history, the properties and the challenges of the cells, some important measurement tools, some simulation programs and a brief survey of the state of the art, aiming to provide an initial framework in this field and serve as a ready reference for all those interested in the subject. This book helps to ""fill in the blanks"" on heterojunction solar cells. Readers will receive a comprehensive overview of the principles, structures, processing techniques and the curre

  19. Solar Cell Panel and the Method for Manufacturing the Same

    Science.gov (United States)

    Richards, Benjamin C. (Inventor); Sarver, Charles F. (Inventor); Naidenkova, Maria (Inventor)

    2016-01-01

    According to an aspect of an embodiment of the present disclosure, there is provided a solar cell panel and a method for manufacturing the same. The solar cell panel comprises: a solar cell for generating electric power from sunlight; a coverglass for covering the solar cell; transparent shims, which are disposed between the solar cell and the coverglass at the points where the distance between the solar cell and the coverglass needs to be controlled, and form a space between the solar cell and the coverglass; and adhesive layer, which fills the space between the solar cell and the coverglass and has the thickness the same as that of the transparent shims.

  20. Combinatorial Sputtering of Ga-Doped (Zn,Mg)O for Contact Applications in Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Rajbhandari, Pravakar P.; Bikowski, Andre; Perkins, John D.; Dhakal, Tara P.; Zakutayev, Andriy

    2017-01-01

    Development of tunable contact materials based on environmentally friendly chemical elements using scalable deposition approaches is necessary for existing and emerging solar energy conversion technologies. In this paper, the properties of ZnO alloyed with magnesium (Mg), and doped with gallium (Ga) are studied using combinatorial thin film experiments. As a result of these studies, the optical band gap of the sputtered Zn1-xMgxO thin films was determined to vary from 3.3 to 3.6 eV for a compositional spread of Mg content in the 0.04 < x < 0.17 range. Depending on whether or not Ga dopants were added, the electron concentrations were on the order of 1017 cm-3 or 1020 cm-3, respectively. Based on these results and on the Kelvin Probe work function measurements, a band diagram was derived using basic semiconductor physics equations. The quantitative determination of how the energy levels of Ga-doped (Zn, Mg)O thin films change as a function of Mg composition presented here, will facilitate their use as optimized contact layers for both Cu2ZnSnS4 (CZTS), Cu(In, Ga)Se2 (CIGS) and other solar cell absorbers.

  1. Dye-sensitized Solar Cells for Solar Energy Harvesting

    Science.gov (United States)

    Roy, M. S.; Deol, Y. S.; Kumar, Manish; Prasad, Narottam; Janu, Yojana

    2011-10-01

    Dye-sensitized solar cells (DSSCs) also known as Gratzel cells, have attracted the interests of researchers to a great extent because of its cost effective and easy manufacturing process without involving highly sophisticated lithographic technique and high cost raw materials as usually seen in conventional solar cell. Based on simple photo-electrochemical process, it has got immense potential in converting solar energy to electrical power in remote and desert area where the supply of conventional power is not possible. The overall peak power-production efficiency of dye-sensitized solar cells has been reported around 11 percent, so they are best suited to low-density applications and the price-to-performance ratio obtained through these solar cells is superior to others. DSSCs have ability to absorb even diffused sunlight and therefore work in cloudy whether as well without much impact over the efficiency. The present communication deals with a review of our work on DSSCs wherein we have used cost effective natural dyes/pigments as a sensitizer of nc-TiO2 and discussed about various key factors affecting the conversion efficiency of DSSC.

  2. Recent Advancements and Techniques in Manufacture of Solar Cells: Organic Solar Cells

    Directory of Open Access Journals (Sweden)

    B. Naga Venkata Sai Ganesh,

    2013-03-01

    Full Text Available The major problem faced by the society is power crisis. All the non-renewable resources like fossil fuelsnecessary for producing power are being used excessively, which might result a day in future where, the world might godark due to lack of power producing resources. Usage of renewable resources like solar energy can be a solution to thisproblem. Solar cells invented to overcome this problem show rigidity in their structure which is a drawback. Inorganicsolar cells are rigid and can be mounted only on rooftops. Hence only upper surface of buildings are utilized. In this paperwe bring out a new era or solar cells- organic solar cells, which are flexible. These organic solar cells offer the bestsolution for the above problem for a tradeoff of efficiency. This paper briefs the manufacturing technique of solar cellsfrom plastic i.e. ,organic polymers, their architecture, the working process of solar energy production from the organicsolar cells with their ease of usage

  3. Recent Advances in Organic Solar Cells

    Directory of Open Access Journals (Sweden)

    Thomas Kietzke

    2007-01-01

    Full Text Available Solar cells based on organic semiconductors have attracted much attention. The thickness of the active layer of organic solar cells is typically only 100 nm thin, which is about 1000 times thinner than for crystalline silicon solar cells and still 10 times thinner than for current inorganic thin film cells. The low material consumption per area and the easy processing of organic semiconductors offer a huge potential for low cost large area solar cells. However, to compete with inorganic solar cells the efficiency of organic solar cells has to be improved by a factor of 2-3. Several organic semiconducting materials have been investigated so far, but the optimum material still has to be designed. Similar as for organic light emitting devices (OLED small molecules are competing with polymers to become the material of choice. After a general introduction into the device structures and operational principles of organic solar cells the three different basic types (all polymer based, all small molecules based and small molecules mixed with polymers are described in detail in this review. For each kind the current state of research is described and the best of class reported efficiencies are listed.

  4. Thin-film crystalline silicon solar cells

    CERN Document Server

    Brendel, Rolf

    2011-01-01

    This introduction to the physics of silicon solar cells focuses on thin cells, while reviewing and discussing the current status of the important technology. An analysis of the spectral quantum efficiency of thin solar cells is given as well as a full set of analytical models. This is the first comprehensive treatment of light trapping techniques for the enhancement of the optical absorption in thin silicon films.

  5. Characterization of damp heat degradation of CuInGaSe2 solar cell components and devices by (electrochemical) impedance spectroscopy

    Science.gov (United States)

    Pern, F. J. John; Noufi, Rommel

    2011-09-01

    This work evaluated the capability of (electrochemical) impedance spectroscopy (IS, or ECIS as used here) to monitor damp heat (DH) stability of contact materials, CuInGaSe2 (CIGS) solar cell components, and devices. Cell characteristics and its variation of the CIGS devices were also examined by the ECIS. Bare and encapsulated sample sets were separately prepared and exposed in an environmental chamber at 85°C and 85% relative humidity (RH). The ECIS results from bare samples tested within 50-100 h of DH exposure allowed the determination of the use of a conducting Ag paste and a low-melting-point solder alloy for making a DH-stable external connection with Au wires. Bare Mo and AlNi grid degraded (corroded) rapidly while Ni was DH-stable. The moisture-dampened Al-doped ZnO (AZO) and bilayer ZnO (BZO) likely underwent hydrolytic "capacitor-forming" reaction by DH, resulting in "transient" behavior of very high resistance in ECIS that was not detected by four-point probe. Using an encapsulation test structure that allowed moisture ingress control, DH-induced degradation (resistance increase) rates of BZO on glass decreased from 0.21 ohm/h using a moisture-permeable Tedlar/Polyester/Tedlar (TPT) backsheet to 1.0 x 10-3 ohm/h using a moisture barrier FG-200 film, while Mo on glass did not exhibit the same conducting degradation and corrosion as the bare samples after over 1270 h DH exposure. CIGS solar cells encapsulated with a TPT backsheet degraded irregularly over 774 h DH exposure. Key resistance and capacitance parameters extracted by curve fitting of impedance data clearly showed the variation and impact of DH exposure on cell characteristics. Profound "depression" or shorting of the "p-n junction capacitor" by DH was evident. ECIS results are shown to correlate reasonably well with the solar cells' currentvoltage (I-V) degrading trends. Furthermore, ECIS analysis was capable of differentiating cell degradation due to "junction capacitor" shorting, damage or

  6. Overview and Challenges of Thin Film Solar Electric Technologies

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. Electron irradiation of modern solar cells

    Science.gov (United States)

    Anspaugh, B. E.; Miyahira, T. F.

    1977-01-01

    A number of modern solar cell types representing 1976 technology (as well as some older types) were irradiated with 1 MeV electrons (and a limited number with 2 MeV electrons and 10 MeV protons). After irradiation, the cells were annealed, with I-V curves measured under AMO at 30 C. The purpose was to provide data to be incorporated in the revision of the solar cell radiation handbook. Cell resistivities ranged from 2 to 20 ohm-cm, and cell thickness from 0.05 to 0.46 mm. Cell types examined were conventional, shallow junction, back surface field (BSF), textured, and textured with BSF.

  8. Inorganic caesium lead iodide perovskite solar cells

    OpenAIRE

    Eperon, GE; Paterno', GM; Sutton, RJ; Zampetti, A.; Haghighirad, A; Cacialli, F.; Snaith, H.

    2015-01-01

    The vast majority of perovskite solar cell research has focused on organic-inorganic lead trihalide perovskites. Herein, we present working inorganic CsPbI3 perovskite solar cells for the first time. CsPbI3 normally resides in a yellow non-perovskite phase at room temperature, but by careful processing control and development of a low-temperature phase transition route we have stabilised the material in the black perovskite phase at room temperature. As such, we have fabricated solar cell dev...

  9. Photoelectrochemical Solar Cells Based on Chitosan Electroylte

    Institute of Scientific and Technical Information of China (English)

    M.H.A.Buraidah; A.K.Arof

    2007-01-01

    1 Results ITO-ZnTe/Chitosan-NH4I-I2/ITO photoelectrochemical solar cells have been fabricated and characterized by current-voltage characteristics.In this work,the ZnTe thin film was prepared by electrodeposition on indium-tin-oxide coated glass.The chitosan electrolyte consists of NH4I salt and iodine.Iodine was added to provide the I3-/I- redox couple.The PEC solar cell was fabricated by sandwiching an electrolyte film between the ZnTe semiconductor and ITO conducting glass.The area of the solar cell...

  10. Metamorphic Epitaxy for Multijunction Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    France, Ryan M.; Dimroth, Frank; Grassman, Tyler J.; King, Richard R.

    2016-03-01

    Multijunction solar cells have proven to be capable of extremely high efficiencies by combining multiple semiconductor materials with bandgaps tuned to the solar spectrum. Reaching the optimum set of semiconductors often requires combining high-quality materials with different lattice constants into a single device, a challenge particularly suited for metamorphic epitaxy. In this article, we describe different approaches to metamorphic multijunction solar cells, including traditional upright metamorphic, state-of-the-art inverted metamorphic, and forward-looking multijunction designs on silicon. We also describe the underlying materials science of graded buffers that enables metamorphic subcells with low dislocation densities. Following nearly two decades of research, recent efforts have demonstrated high-quality lattice-mismatched multijunction solar cells with very little performance loss related to the mismatch, enabling solar-to-electric conversion efficiencies over 45%.

  11. Recent Advances in Dye Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Umer Mehmood

    2014-01-01

    Full Text Available Solar energy is an abundant and accessible source of renewable energy available on earth, and many types of photovoltaic (PV devices like organic, inorganic, and hybrid cells have been developed to harness the energy. PV cells directly convert solar radiation into electricity without affecting the environment. Although silicon based solar cells (inorganic cells are widely used because of their high efficiency, they are rigid and manufacturing costs are high. Researchers have focused on organic solar cells to overcome these disadvantages. DSSCs comprise a sensitized semiconductor (photoelectrode and a catalytic electrode (counter electrode with an electrolyte sandwiched between them and their efficiency depends on many factors. The maximum electrical conversion efficiency of DSSCs attained so far is 11.1%, which is still low for commercial applications. This review examines the working principle, factors affecting the efficiency, and key challenges facing DSSCs.

  12. Optical models for silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, T.; Sopori, B. [National Renewable Energy Lab., Golden, CO (United States)

    1995-08-01

    Light trapping is an important design feature for high-efficiency silicon solar cells. Because light trapping can considerably enhance optical absorption, a thinner substrate can be used which, in turn, can lower the bulk carrier recombination and concommitantly increase open-circuit voltage, and fill factor of the cell. The basic concepts of light trapping are similar to that of excitation of an optical waveguide, where a prism or a grating structure increases the phase velocity of the incoming optical wave such that waves propagated within the waveguide are totally reflected at the interfaces. Unfortunately, these concepts break down because the entire solar cell is covered with such a structure, making it necessary to develop new analytical approaches to deal with incomplete light trapping in solar cells. This paper describes two models that analyze light trapping in thick and thin solar cells.

  13. MoSe2 / Polyaniline Solar Cells

    Directory of Open Access Journals (Sweden)

    H.S. Patel

    2011-01-01

    Full Text Available Solar cells have been investigated since long for harnessing the solar energy. During this decade, a new direction has come up where in the polymers have been used in the fabrication of solar cells. Polyaniline is one of the polymers which has shown potential for its applications in heterostructure solar cells. This material is being used along with the semiconductors like InSe, TiO2, Si etc. to form the photosensitive interface. In this direction, we report our investigations on the use of Molybdenum diselenide (MoSe2 as photosensitive semiconducting material in MoSe2 / polyaniline solar cells. In this paper, the preparation of MoSe2 / polyaniline solar cells has been reported. Also, the photovoltage → photocurrent characteristics of this structure have been discussed in detail in this paper. The variation of different parameters of MoSe2 / polyaniline solar cells (like open circuit voltage, short circuit current, photoconversion efficiency and fill factor with the intensity of incident illuminations has been reported in this paper. In present case, the photocurrent density was found to be around 250 µA/cm2 with the photovoltage around 8.5 mV (which is low the photoconversion efficiency was found to be around 0.7 % along with the fill factor around 0.33. The efforts have been made to explain the low values of the photoconversion efficiency.

  14. Coupling of Luminescent Solar Concentrators to Plasmonic Solar Cells

    Science.gov (United States)

    Wang, Shu-Yi

    To make inexpensive solar cells is a continuous goal for solar photovoltaic (PV) energy industry. Thin film solar cells of various materials have been developed and continue to emerge in order to replace bulk silicon solar cells. A thin film solar cell not only uses less material but also requires a less expensive refinery process. In addition, other advantages coming along with small thickness are higher open circuit voltage and higher conversion efficiency. However, thin film solar cells, especially those made of silicon, have significant optical losses. In order to address this problem, this thesis investigates the spectral coupling of thin films PV to luminescent solar concentrators (LSC). LSC are passive devices, consisting of plastic sheets embedded with fluorescent dyes which absorb part of the incoming radiation spectrum and emit at specific wavelength. The emitted light is concentrated by total internal reflection to the edge of the sheet, where the PVs are placed. Since the light emitted from the LSC edge is usually in a narrow spectral range, it is possible to employ diverse strategies to enhance PV absorption at the peak of the emission wavelength. Employing plasmonic nanostructures has been shown to enhance absorption of thin films via forward scattering, diffraction and localized surface plasmon. These two strategies are theoretically investigated here for improving the absorption and elevating the output power of a thin film solar cell. First, the idea of spectral coupling of luminescent solar concentrators to plasmonic solar cells is introduced to assess its potential for increasing the power output. This study is carried out employing P3HT/PC60BM organic solar cells and LSC with Lumogen Red dyes. A simplified spectral coupling analysis is employed to predict the power density, considering the output spectrum of the LSC equivalent to the emission spectrum of the dye and neglecting any angular dependence. Plasmonic tuning is conducted to enhance

  15. 8 MeV electron irradiation studies on electrical characteristics of Cu(In,Ga)Se{sub 2} solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Rao, Asha [Department of Physics, Mangalore Institute of Technology and Engineering, Moodabidri, Mangalore 574 227 (India); Krishnan, Sheeja; Sanjeev, Ganesh [Microtron Centre, Department of Physics, Mangalore University, Mangalagangothri 574 199 (India); Siddappa, K. [JSS Foundation for Science and Society, Bangalore 560 085 (India); Ullal, Harin S.; Wu, Xuanzhi [National Center for Photovoltaics, National Renewable Energy Laboratory, 1617, Cole Boulevard, Golden, CO 80401 (United States)

    2009-09-15

    Cu(In,Ga)Se{sub 2} (CIGS) solar cells are gaining considerable interest due to their high optical absorption coefficient and adjustable band gap, which enables them to achieve high conversion efficiency and also present many promising applications in space power systems. In this paper we report the results of the effect of temperature and 8 MeV electron irradiation on the electrical characteristics of ZnO/CdS/Cu(In,Ga)Se{sub 2}/Mo polycrystalline thin-film solar cells under forward and reverse bias studied in the temperature range 270-315 K. The solar cells were subjected to 8 MeV electron irradiation from the Microtron accelerator and were exposed to graded doses of electrons up to 75 kGy. I-V characteristics of the cells under dark and AM 1.5 illumination condition were studied before and after the irradiation. Capacitance measurements were also carried out at various frequencies before and after irradiation. In the measured temperature range, the dark current contribution is due to the generation-recombination of the minority carriers in the depletion region. The ideality factor is found to decrease with increase in temperature. It seems that electron irradiation has not altered the dark current conduction mechanism significantly. The effect of electron irradiation on the solar cell parameters such as fill factor (FF), conversion efficiency ({eta}), saturation current (I{sub o}), short circuit current (I{sub sc}), open circuit voltage (V{sub oc}), and ideality factor (n) was studied. They were found to be stable up to 75 kGy of electron dose as only small changes were observed in the solar cell parameters. (author)

  16. Intrinsic ZnO films fabricated by DC sputtering from oxygen-deficient targets for Cu(In,Ga)Se2 solar cell application

    Institute of Scientific and Technical Information of China (English)

    Chongyin Yang; DongyunWan; Zhou Wang; Fuqiang Huang

    2011-01-01

    Intrinsic zinc oxide films, normally deposited by radio frequency (RF) sputtering, are fabricated by direct current (DC) sputtering. The oxygen-deficient targets are prepared via a newly developed double crucible method. The 800-nm-thick film obtaines significantly higher carrier mobility compareing with that of the 800-nm-thick ZnO film. This is achieved by the widely used RF sputtering, which favors the prevention of carrier recombination at the interfaces and reduction of the series resistance of solar cells. The optimal ZnO film is used in a Cu (In, Ga) Se2 (CIGS) solar cell with a high efficiency of 11.57%. This letter demonstrates that the insulating ZnO films can be deposited by DC sputtering from oxygen-deficient ZnO targets to lower the cost of thin film solar cells.%Intrinsic zinc oxide films,normally deposited by radio frequency (RF) sputtering,are fabricated by direct current (DC) sputtering.The oxygen-deficient targets are prepared via a newly developed double crucible method.The 800-nm-thick film obtaines significantly higher carrier mobility compareing with that of the 800-nm-thick ZnO film.This is achieved by the widely used RF sputtering,which favors the prevention of carrier recombination at the interfaces and reduction of the series resistance of solar cells.The optimal ZnO film is used in a Cu (In,Ga) Se2 (C1GS) solar cell with a high efficiency of 11.57%.This letter demonstrates that the insulating ZnO films can be deposited by DC sputtering from oxygen-deficient ZnO targets to lower the cost of thin film solar cells.High resistance transparent intrinsic zinc oxide (i-ZnO)thin film has been widely nsed as the front electrode in transparent electronics and photovoltaic devices because of its low cost and nontoxicity.Owing to its unique characteristics of high transparency and adjustable resistivity in a certain range,the use of i-ZnO thin films as diffusion barrier layers of a-Si/μc-Si,CdTe,and CIGS thin-film solar cells has been advantageous

  17. Cu元素对Cu(In,Ga)Se2薄膜及太阳电池的影响%Effects of Cu elements on Cu(In,Ga)Se2 film and solar cell

    Institute of Scientific and Technical Information of China (English)

    刘芳芳; 何青; 周志强; 孙云

    2014-01-01

    The Cu elements of Cu (In, Ga) Se2 (CIGS) have very important influences on the electrical properties of CIGS absorber and solar cells. In this paper, Cu-poor and Cu-rich absorber layers (0.7solar cells are prepared by evaporation method. The SEM and Hall measurements reveal that Cu-rich material shows superior structural (larger grain size, better crystalline) and electrical (lower resistivity, higher mobility) properties to Cu-poor material. However, I-V tests show that the efficiency of Cu-poor solar cell is better than that of the Cu-rich device. The temperature-dependent I-V tests indicate that electron loss is mainly due to the bulk recombination in Cu-poor solar cell, and the activation energy of recombination is comparable to the band gap energy of Cu-poor solar cell. In contrast, in the Cu-rich devices the recombination at the heterointerface is dominant, and the activation energy is smaller than the band gap energy of the absorber material, which is an important drawback of open circuit voltage. Finally, Cu-poor surface on Cu-rich absorber is prepared by three-stage evaporation process, which reduces the short-circuit current and open-circuit voltage loss and optimizes the performance of CIGS solar cells. The efficiency of CIGS solar cell is achieved to be as high as more than 15%.%Cu元素成分对Cu(In, Ga)Se2(简称CIGS)薄膜材料的电学性质及其电池器件性能有很重要的影响.本文利用蒸发法制备了贫Cu和富Cu的CIGS吸收层(0.7

  18. Microcrystalline silicon and micromorph tandem solar cells

    OpenAIRE

    Keppner, H.; Meier, Johannes; Torres, P.; Fischer, D.; Shah, A.

    2008-01-01

    “Micromorph” tandem solar cells consisting of a microcrystalline silicon bottom cell and an amorphous silicon top cell are considered as one of the most promising new thin-film silicon solar-cell concepts. Their promise lies in the hope of simultaneously achieving high conversion efficiencies at relatively low manufacturing costs. The concept was introduced by IMT Neuchâtel, based on the VHF-GD (very high frequency glow discharge) deposition method. The key element of the micromorph cell is t...

  19. Towards high performance inverted polymer solar cells

    Science.gov (United States)

    Gong, Xiong

    2013-03-01

    Bulk heterojunction polymer solar cells that can be fabricated by solution processing techniques are under intense investigation in both academic institutions and industrial companies because of their potential to enable mass production of flexible and cost-effective alternative to silicon-based electronics. Despite the envisioned advantages and recent technology advances, so far the performance of polymer solar cells is still inferior to inorganic counterparts in terms of the efficiency and stability. There are many factors limiting the performance of polymer solar cells. Among them, the optical and electronic properties of materials in the active layer, device architecture and elimination of PEDOT:PSS are the most determining factors in the overall performance of polymer solar cells. In this presentation, I will present how we approach high performance of polymer solar cells. For example, by developing novel materials, fabrication polymer photovoltaic cells with an inverted device structure and elimination of PEDOT:PSS, we were able to observe over 8.4% power conversion efficiency from inverted polymer solar cells.

  20. Ecofriendly and Nonvacuum Electrostatic Spray-Assisted Vapor Deposition of Cu(In,Ga)(S,Se)2 Thin Film Solar Cells.

    Science.gov (United States)

    Hossain, Md Anower; Wang, Mingqing; Choy, Kwang-Leong

    2015-10-14

    Chalcopyrite Cu(In,Ga)(S,Se)2 (CIGSSe) thin films have been deposited by a novel, nonvacuum, and cost-effective electrostatic spray-assisted vapor deposition (ESAVD) method. The generation of a fine aerosol of precursor solution, and their controlled deposition onto a molybdenum substrate, results in adherent, dense, and uniform Cu(In,Ga)S2 (CIGS) films. This is an essential tool to keep the interfacial area of thin film solar cells to a minimum value for efficient charge separation as it helps to achieve the desired surface smoothness uniformity for subsequent cadmium sulfide and window layer deposition. This nonvacuum aerosol based approach for making the CIGSSe film uses environmentally benign precursor solution, and it is cheaper for producing solar cells than that of the vacuum-based thin film solar technology. An optimized CIGSSe thin film solar cell with a device configuration of molybdenum-coated soda-lime glass substrate/CIGSSe/CdS/i-ZnO/AZO shows the photovoltaic (j-V) characteristics of Voc=0.518 V, jsc=28.79 mA cm(-2), fill factor=64.02%, and a promising power conversion efficiency of η=9.55% under simulated AM 1.5 100 mW cm(-2) illuminations, without the use of an antireflection layer. This demonstrates the potential of ESAVD deposition as a promising alternative approach for making thin film CIGSSe solar cells at a lower cost. PMID:26390182

  1. Heavily doped polysilicon-contact solar cells

    Science.gov (United States)

    Lindholm, F. A.; Neugroschel, A.; Arienzo, M.; Iles, P. A.

    1985-01-01

    The first use of a (silicon)/heavily doped polysilicon)/(metal) structure to replace the conventional high-low junction or back-surface-field (BSF) structure of silicon solar cells is reported. Compared with BSF and back-ohmic-contact (BOC) control samples, the polysilicon-back solar cells show improvements in red spectral response (RSR) and open-circuit voltage. Measurement reveals that a decrease in effective surface recombination velocity S is responsible for this improvement. Decreased S results for n-type (Si:As) polysilicon, consistent with past findings for bipolar transistors, and for p-type (Si:B) polysilicon, reported here for the first time. Though the present polysilicon-back solar cells are far from optimal, the results suggest a new class of designs for high efficiency silicon solar cells. Detailed technical reasons are advanced to support this view.

  2. Solar Cell Efficiency Tables (Version 48)

    Energy Technology Data Exchange (ETDEWEB)

    Green, Martin A.; Emery, Keith; Hishikawa, Yoshihiro; Warta, Wilhelm; Dunlop, Ewan D.

    2016-07-01

    Consolidated tables showing an extensive listing of the highest independently confirmed efficiencies for solar cells and modules are presented. Guidelines for inclusion of results into these tables are outlined, and new entries since January 2016 are reviewed.

  3. Black Silicon Solar Cells with Black Ribbons

    DEFF Research Database (Denmark)

    Davidsen, Rasmus Schmidt; Tang, Peter Torben; Mizushima, Io;

    2016-01-01

    We present the combination of mask-less reactive ion etch (RIE) texturing and blackened interconnecting ribbons as a method for obtaining all-black solar panels, while using conventional, front-contacted solar cells. Black silicon made by mask-less reactive ion etching has total, average...... in the range 15.7-16.3%. The KOH-textured reference cell had an efficiency of 17.9%. The combination of black Si and black interconnecting ribbons may result in aesthetic, all-black panels based on conventional, front-contacted silicon solar cells....... reflectance below 0.5% across a 156x156 mm2 silicon (Si) wafer. Black interconnecting ribbons were realized by oxidizing copper resulting in reflectance below 3% in the visible wavelength range. Screen-printed Si solar cells were realized on 156x156 mm2 black Si substrates with resulting efficiencies...

  4. Electrospun Polymer-Fiber Solar Cell

    Directory of Open Access Journals (Sweden)

    Shinobu Nagata

    2013-01-01

    Full Text Available A novel electrospun polymer-fiber solar cell was synthesized by electrospinning a 1 : 2.5 weight% ratio mixture of poly[2-methoxy-5-(2-ethylhexyloxy-1,4-phenylenevinylene] (MEH-PPV and [6,6]-phenyl C61 butyric acid methyl ester (PCBM resulting in bulk heterojunctions. Electrospinning is introduced as a technique that may increase polymer solar cell efficiency, and a list of advantages of the technique applied to solar cells is discussed. The device achieved a power conversion efficiency of %. The absorption and photoluminescence of MEH-PPV nanofibers are compared to thin films of the same material. Electrospun nanofibers are discussed as a favorable structure for application in polymer solar cells.

  5. Multijunction Ultralight Solar Cells and Arrays Project

    Data.gov (United States)

    National Aeronautics and Space Administration — There is a continuing need within NASA for solar cells and arrays with very high specific power densities (1000-5000 kW/kg) for generating power in a new generation...

  6. A space solar cell bonding robot

    Institute of Scientific and Technical Information of China (English)

    FU Zhuang; ZHAO Yan-zheng; LIU Ren-qiang; DONG Zhi

    2006-01-01

    A space solar cell bonding robot system which consists of a three-axis Cartesian coordinate's robot,coating device,bonding device,orientation plate,and control subsystem was studied.A method,which can control the thickness of adhesive layer on the solar cell,was put forward and the mechanism was designed.Another method which can achieve the auto-bonding between thin coverglass and the space solar cell was studied and realized.It produced no air bubble in the adhesives layer under the condition of no vacuum environment,and ensures the assembly dislocation ≤0.1 mm.Compared to the conventional method,it has advantages such as no fragment exists,and no adhesives outflow onto the cover-glass and solar cells.

  7. High Efficiency, Deployable Solar Cells Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Ultrathin, lightweight, flexible, and easily deployable solar cell (SC) capable of specific power greater than 1kW/kg are at an early stage of development for...

  8. Toxicity of organometal halide perovskite solar cells

    Science.gov (United States)

    Babayigit, Aslihan; Ethirajan, Anitha; Muller, Marc; Conings, Bert

    2016-03-01

    In the last few years, the advent of metal halide perovskite solar cells has revolutionized the prospects of next-generation photovoltaics. As this technology is maturing at an exceptional rate, research on its environmental impact is becoming increasingly relevant.

  9. E-Cig Liquid Nicotine Containers Often Mislabeled

    Science.gov (United States)

    ... medlineplus.gov/news/fullstory_160108.html E-Cig Liquid Nicotine Containers Often Mislabeled Also, many aren't ... July 27, 2016 (HealthDay News) -- Containers that hold liquid nicotine for electronic cigarettes may not be labeled ...

  10. Are E-Cigs Slowing Teen Anti-Smoking Push?

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_159809.html Are E-Cigs Slowing Teen Anti-Smoking Push? Researchers blame ... a new study contends. "We found evidence that e-cigarettes are recruiting at least some youth who ...

  11. Solar cells on the base of organic semiconductors

    International Nuclear Information System (INIS)

    The parameters of organic solar cells on the base of different organic semiconductors as poly epoxypropyl carbazole, copper phthalocyanine and bordeaux perylene are considered. Moreover the properties of solar cells on the base of n-GaAs and copper phthalocyanine heterostructure are described. The new technologies in the field of organic solar cells as bulk heterostructure solar cells are discussed. (author)

  12. Singlet fission: Towards efficient solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Havlas, Zdeněk; Wen, Jin [Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 16610 Prague 6 (Czech Republic); Michl, Josef [Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215 (United States); Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 16610 Prague 6 (Czech Republic)

    2015-12-31

    Singlet fission (SF) offers an opportunity to improve solar cell efficiency, but its practical use is hindered by the limited number of known efficient materials, limited knowledge of SF mechanism, mainly the relation between the dimer structure and SF efficiency and diffusion of the triplet states allowing injection of electrons into the solar cell semiconductor band. Here we report on our attempt to design new classes of chromophores and to study the relation between the structure and SF efficiency.

  13. Singlet fission: Towards efficient solar cells

    International Nuclear Information System (INIS)

    Singlet fission (SF) offers an opportunity to improve solar cell efficiency, but its practical use is hindered by the limited number of known efficient materials, limited knowledge of SF mechanism, mainly the relation between the dimer structure and SF efficiency and diffusion of the triplet states allowing injection of electrons into the solar cell semiconductor band. Here we report on our attempt to design new classes of chromophores and to study the relation between the structure and SF efficiency

  14. Multijunction Solar Cells Optimized for the Mars Surface Solar Spectrum

    Science.gov (United States)

    Edmondson, Kenneth M.; Fetzer, Chris; Karam, Nasser H.; Stella, Paul; Mardesich, Nick; Mueller, Robert

    2007-01-01

    This paper gives an update on the performance of the Mars Exploration Rovers (MER) which have been continually performing for more than 3 years beyond their original 90-day missions. The paper also gives the latest results on the optimization of a multijunction solar cell that is optimized to give more power on the surface of Mars.

  15. Perovskite Solar Cells: Progress and Advancements

    Directory of Open Access Journals (Sweden)

    Naveen Kumar Elumalai

    2016-10-01

    Full Text Available Organic–inorganic hybrid perovskite solar cells (PSCs have emerged as a new class of optoelectronic semiconductors that revolutionized the photovoltaic research in the recent years. The perovskite solar cells present numerous advantages include unique electronic structure, bandgap tunability, superior charge transport properties, facile processing, and low cost. Perovskite solar cells have demonstrated unprecedented progress in efficiency and its architecture evolved over the period of the last 5–6 years, achieving a high power conversion efficiency of about 22% in 2016, serving as a promising candidate with the potential to replace the existing commercial PV technologies. This review discusses the progress of perovskite solar cells focusing on aspects such as superior electronic properties and unique features of halide perovskite materials compared to that of conventional light absorbing semiconductors. The review also presents a brief overview of device architectures, fabrication methods, and interface engineering of perovskite solar cells. The last part of the review elaborates on the major challenges such as hysteresis and stability issues in perovskite solar cells that serve as a bottleneck for successful commercialization of this promising PV technology.

  16. Electrospinning Nanofiber Based Organic Solar Cell

    Science.gov (United States)

    Yang, Zhenhua; Liu, Ying; Moffa, Maria; Nam, Chang-Yong; Pisignano, Dario; Rafailovich, Miriam

    Bulk heterojunction (BHJ) polymer solar cells are an area of intense interest due to their potential to result in printable, inexpensive solar cells which can be processed onto flexible substrates. The active layer is typically spin coated from the solution of polythiophene derivatives (donor) and fullerenes (acceptor) and interconnected domains are formed because of phase separation. However, the power conversion efficiency (PCE) of BHJ solar cell is restricted by the presence of unfavorable morphological features, including dead ends or isolated domains. Here we MEH-PPV:PVP:PCBM electrospun nanofiber into BHJ solar cell for the active layer morphology optimization. Larger interfacial area between donor and acceptor is abtained with electrospinning method and the high aspect ratio of the MEH-PPV:PVP:PCBM nanofibers allow them to easily form a continuous pathway. The surface morphology is investigated with atomic force microscopy (AFM) and scanning electron microscopy (SEM). Electrospun nanofibers are discussed as a favorable structure for application in bulk-heterojunction organic solar cells. Electrospinning Nanofiber Based Bulk Heterojunction Organic Solar Cell.

  17. Effect of solar-terrestrial phenomena on solar cell's efficiency

    International Nuclear Information System (INIS)

    It is assumed that the solar cell efficiency of PV device is closely related to the solar irradiance, consider the solar parameter Global Solar Irradiance (G) and the meteorological parameters like daily data of Earth Skin Temperature (E), Average Temperature (T), Relative Humidity (H) and Dew Frost Point (D), for the coastal city Karachi and a non-coastal city Jacobabad, K and J is used as a subscripts for parameters of Karachi and Jacobabad respectively. All variables used here are dependent on the location (latitude and longitude) of our stations except G. To employ ARIMA modeling, the first eighteen years data is used for modeling and forecast is done for the last five years data. In most cases results show good correlation among monthly actual and monthly forecasted values of all the predictors. Next, multiple linear regression is employed to the data obtained by ARIMA modeling and models for mean monthly observed G values are constructed. For each station, two equations are constructed, the R values are above 93% for each model, showing adequacy of the fit. Our computations show that solar cell efficiency can be increased if better modeling for meteorological predictors governs the process. (author)

  18. Nanocrystalline silicon based thin film solar cells

    Science.gov (United States)

    Ray, Swati

    2012-06-01

    Amorphous silicon solar cells and panels on glass and flexible substrate are commercially available. Since last few years nanocrystalline silicon thin film has attracted remarkable attention due to its stability under light and ability to absorb longer wavelength portion of solar spectrum. For amorphous silicon/ nanocrystalline silicon double junction solar cell 14.7% efficiency has been achieved in small area and 13.5% for large area modules internationally. The device quality nanocrystalline silicon films have been fabricated by RF and VHF PECVD methods at IACS. Detailed characterizations of the materials have been done. Nanocrystalline films with low defect density and high stability have been developed and used as absorber layer of solar cells.

  19. Application of femtosecond laser ablation inductively coupled plasma mass spectrometry for quantitative analysis of thin Cu(In,Ga)Se2 solar cell films

    International Nuclear Information System (INIS)

    This work reports that the composition of Cu(In,Ga)Se2 (CIGS) thin solar cell films can be quantitatively predicted with high accuracy and precision by femtosecond laser ablation-inductively coupled plasma-mass spectrometry (fs-LA-ICP-MS). It is demonstrated that the results are strongly influenced by sampling conditions during fs-laser beam (λ = 1030 nm, τ = 450 fs) scanning on the CIGS surface. The fs-LA-ICP-MS signals measured at optimal sampling conditions generally provide a straight line calibration with respect to the reference concentrations measured by inductively coupled plasma optical emission spectroscopy (ICP-OES). The concentration ratios predicted by fs-LA-ICP-MS showed high accuracy, to 95–97% of the values measured with ICP-OES, for Cu, In, Ga, and Se elements. - Highlights: • Laser ablation inductively coupled plasma mass spectrometry of thin film is reported. • Concentration ratio prediction with a confidence level of 95–97% is achieved. • Quantitative determination of composition is demonstrated

  20. Application of femtosecond laser ablation inductively coupled plasma mass spectrometry for quantitative analysis of thin Cu(In,Ga)Se{sub 2} solar cell films

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seokhee [School of Mechatronics, Gwangju Institute of Science and Technology, 1 Oryong-dong, Buk-gu, Gwangju 500-712 (Korea, Republic of); Gonzalez, Jhanis J. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Applied Spectra Inc., 46665 Fremont Boulevard, Fremont, CA 94538 (United States); Yoo, Jong H. [Applied Spectra Inc., 46665 Fremont Boulevard, Fremont, CA 94538 (United States); Chirinos, Jose R. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Facultad de Ciencias, Universidad Central de Venezuela, Caracas 1041A (Venezuela, Bolivarian Republic of); Russo, Richard E. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Applied Spectra Inc., 46665 Fremont Boulevard, Fremont, CA 94538 (United States); Jeong, Sungho, E-mail: shjeong@gist.ac.kr [School of Mechatronics, Gwangju Institute of Science and Technology, 1 Oryong-dong, Buk-gu, Gwangju 500-712 (Korea, Republic of)

    2015-02-27

    This work reports that the composition of Cu(In,Ga)Se{sub 2} (CIGS) thin solar cell films can be quantitatively predicted with high accuracy and precision by femtosecond laser ablation-inductively coupled plasma-mass spectrometry (fs-LA-ICP-MS). It is demonstrated that the results are strongly influenced by sampling conditions during fs-laser beam (λ = 1030 nm, τ = 450 fs) scanning on the CIGS surface. The fs-LA-ICP-MS signals measured at optimal sampling conditions generally provide a straight line calibration with respect to the reference concentrations measured by inductively coupled plasma optical emission spectroscopy (ICP-OES). The concentration ratios predicted by fs-LA-ICP-MS showed high accuracy, to 95–97% of the values measured with ICP-OES, for Cu, In, Ga, and Se elements. - Highlights: • Laser ablation inductively coupled plasma mass spectrometry of thin film is reported. • Concentration ratio prediction with a confidence level of 95–97% is achieved. • Quantitative determination of composition is demonstrated.

  1. Electron irradiation of tandem junction solar cells

    Science.gov (United States)

    Anspaugh, B. E.; Miyahira, T. F.; Scott-Monck, J. A.

    1979-01-01

    The electrical behavior of 100 micron thick tandem junction solar cells manufactured by Texas Instruments was studied as a function of 1 MeV electron fluence, photon irradiation, and 60 C annealing. These cells are found to degrade rapidly with radiation, the most serious loss occurring in the blue end of the cell's spectral response. No photon degradation was found to occur, but the cells did anneal a small amount at 60 C.

  2. Selective Ablation of Thin Films with Picosecond-Pulsed Lasers for Solar Cells

    Science.gov (United States)

    Račiukaitis, G.; Gečys, P.; Gedvilas, M.; Regelskis, K.; Voisiat, B.

    2010-10-01

    Functional thin-films are of high importance in modern electronics for flat panel displays, photovoltaics, flexible and organic electronics. Versatile technologies are required for patterning thin-film materials on rigid and flexible substrates. The large-area applications of thin films such as photovoltaics need high speed and simple to use techniques. Ultra-short laser processing with its flexibility is one of the ways to achieve high quality material etching but optimization of the processes is required to meet specific needs of the applications. Lasers with picosecond pulse duration were applied in selective ablation of conducting, semi-conducting and isolating films in the complex multilayered thin-film solar cells based on amorphous Si and CuInxGa(1-x)Se2 (CIGS) deposited on glass and polymer substrates. Modeling of energy transition between the layers and temperature evolution was performed to understand the processes. Selection of the right laser wavelength was important to keep the energy coupling in a well defined volume at the interlayer interface. Ultra-short pulses ensured high energy input rate into absorbing material permitting peeling of the layers with no influence on the remaining material. Use of high repetition rate lasers with picosecond pulse duration offers new possibilities for high quality and efficiency patterning of advanced materials for thin-film electronics.

  3. Cost and Reliability Improvement for CIGS-Based PV on Flexible Substrate: May 24, 2006 -- July 31, 2010

    Energy Technology Data Exchange (ETDEWEB)

    Wiedeman, S.

    2011-05-01

    Global Solar Energy rapidly advances the cost and performance of commercial thin-film CIGS products using roll-to-roll processing on steel foil substrate in compact, low cost deposition equipment, with in-situ sensors for real-time intelligent process control. Substantial increases in power module efficiency, which now exceed 13%, are evident at GSE factories in two countries with a combined capacity greater than 75 MW. During 2009 the average efficiency of cell strings (3780 cm2) was increased from 7% to over 11%, with champion results exceeding 13% Continued testing of module reliability in rigid product has reaffirmed extended life expectancy for standard glass product, and has qualified additional lower-cost methods and materials. Expected lifetime for PV in flexible packages continues to increase as failure mechanisms are elucidated, and resolved by better methods and materials. Cost reduction has been achieved through better materials utilization, enhanced vendor and material qualification and selection. The largest cost gains have come as a result of higher cell conversion efficiency and yields, higher processing rates, greater automation and improved control in all process steps. These improvements are integral to this thin film PV partnership program, and all realized with the 'Gen2' manufacturing plants, processes and equipment.

  4. Organic solar cells fundamentals, devices, and upscaling

    CERN Document Server

    Rand, Barry P

    2014-01-01

    Solution-Processed DonorsB. Burkhart, B. C. ThompsonSmall-Molecule and Vapor-Deposited Organic Photovoltaics R. R. Lunt, R. J. HolmesAcceptor Materials for Solution-Processed Solar Cells Y. HeInterfacial Layers R. Po, C. Carbonera, A. BernardiElectrodes in Organic Photovoltaic Cells S. Yoo, J.-Y. Lee, H. Kim, J. LeeTandem and Multi-Junction Organic Solar Cells J. Gilot, R. A. J. JanssenBulk Heterojunction Morphology Control and Characterization T. Wang, D. G. LidzeyOptical Modeling and Light Management

  5. Microscopic optoelectronic defectoscopy of solar cells

    Directory of Open Access Journals (Sweden)

    Dallaeva D.

    2013-05-01

    Full Text Available Scanning probe microscopes are powerful tool for micro- or nanoscale diagnostics of defects in crystalline silicon solar cells. Solar cell is a large p-n junction semiconductor device. Its quality is strongly damaged by the presence of defects. If the cell works under low reverse-biased voltage, defects emit a light in visible range. The suggested method combines three different measurements: electric noise measurement, local topography and near-field optical beam induced current and thus provides more complex information. To prove its feasibility, we have selected one defect (truncated pyramid in the sample, which emitted light under low reverse-biased voltage.

  6. Scaling Up ITO-free solar cells

    DEFF Research Database (Denmark)

    Galagan, Yulia; Coenen, Erica W. C.; Zimmermann, Birger;

    2014-01-01

    Indium-tin-oxide-free (ITO-free) polymer solar cells with composite electrodes containing current-collecting grids and a semitransparent poly(3,4-ethylenedioxythiophene):polystyrenesulfonate) (PEDOT:PSS) conductor are demonstrated. The up-scaling of the length of the solar cell from 1 to 6 cm...... and the effect of the grid line resistance are explored for a series of devices. Laser-beam-induced current (LBIC) mapping is used for quality control of the devices. A theoretical modeling study is presented that enables the identification of the most rational cell dimension for the grids with different...... resistances. The performance of ITO-free organic solar cells with different dimensions and different electrode resistances are evaluated for different light intensities. The current generation and electric potential distribution are found to not be uniformly distributed in large-area devices at simulated 1...

  7. Influence of radiation on the properties of solar cells

    OpenAIRE

    Zdravković Miloš R.; Vasić Aleksandra I.; Radosavljević Radovan Lj.; Vujisić Miloš Lj.; Osmokrović Predrag V.

    2011-01-01

    The wide substitution of conventional types of energy by solar energy lies in the rate of developing solar cell technology. Silicon is still the mostly used element for solar cell production, so efforts are directed to the improvement of physical properties of silicon structures. There are several trends in the development of solar cells, but mainly two directions are indicated: the improvement of the conventional solar cell characteristics based on semiconductor materials, and explorin...

  8. Neutral Color Semitransparent Microstructured Perovskite Solar Cells

    KAUST Repository

    Eperon, Giles E.

    2014-01-28

    Neutral-colored semitransparent solar cells are commercially desired to integrate solar cells into the windows and cladding of buildings and automotive applications. Here, we report the use of morphological control of perovskite thin films to form semitransparent planar heterojunction solar cells with neutral color and comparatively high efficiencies. We take advantage of spontaneous dewetting to create microstructured arrays of perovskite "islands", on a length-scale small enough to appear continuous to the eye yet large enough to enable unattenuated transmission of light between the islands. The islands are thick enough to absorb most visible light, and the combination of completely absorbing and completely transparent regions results in neutral transmission of light. Using these films, we fabricate thin-film solar cells with respectable power conversion efficiencies. Remarkably, we find that such discontinuous films still have good rectification behavior and relatively high open-circuit voltages due to the inherent rectification between the n- and p-type charge collection layers. Furthermore, we demonstrate the ease of "color-tinting" such microstructured perovksite solar cells with no reduction in performance, by incorporation of a dye within the hole transport medium. © 2013 American Chemical Society.

  9. Solar cell and its manufacturing process

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Hisashi; Komatsu, Yasumitsu.

    1989-01-20

    The solar cell with a structure of the Cds sintered film/CdTe sintered film is excellent at mass productivity because of usage of screen printing, but its conversion efficiency is insufficient in comparison with that of the single crystal silicon solar cell. Since the CdS/CdTe solar cell is a heterojunction solar cell, it is necessary that lattice constants of two materials are close each other in order to improve its performance. However, the mismatching of the lattices of CdS and CdTe is as fairly big as 11%. In order to ameliorate this mismatching, this invention substitutes the CdTe sintered film with the CdS-CdTe mixed crystal sintered film. Besides, the CdS-CdTe mixed crystal phase has its narrow forbidden bandwidth at or below 50 mol % of its CdS content, hence with it, a solar cell can be obtained which is highly sensitive to the light of long wave lengths. 2 tabs.

  10. Antimony selenide thin-film solar cells

    Science.gov (United States)

    Zeng, Kai; Xue, Ding-Jiang; Tang, Jiang

    2016-06-01

    Due to their promising applications in low-cost, flexible and high-efficiency photovoltaics, there has been a booming exploration of thin-film solar cells using new absorber materials such as Sb2Se3, SnS, FeS2, CuSbS2 and CuSbSe2. Among them, Sb2Se3-based solar cells are a viable prospect because of their suitable band gap, high absorption coefficient, excellent electronic properties, non-toxicity, low cost, earth-abundant constituents, and intrinsically benign grain boundaries, if suitably oriented. This review surveys the recent development of Sb2Se3-based solar cells with special emphasis on the material and optoelectronic properties of Sb2Se3, the solution-based and vacuum-based fabrication process and the recent progress of Sb2Se3-sensitized and Sb2Se3 thin-film solar cells. A brief overview further addresses some of the future challenges to achieve low-cost, environmentally-friendly and high-efficiency Sb2Se3 solar cells.

  11. Light-trapping in perovskite solar cells

    Directory of Open Access Journals (Sweden)

    Qing Guo Du

    2016-06-01

    Full Text Available We numerically demonstrate enhanced light harvesting efficiency in both CH3NH3PbI3 and CH(NH22PbI3-based perovskite solar cells using inverted vertical-cone photonic-crystal nanostructures. For CH3NH3PbI3 perovskite solar cells, the maximum achievable photocurrent density (MAPD reaches 25.1 mA/cm2, corresponding to 92% of the total available photocurrent in the absorption range of 300 nm to 800 nm. Our cell shows 6% absorption enhancement compared to the Lambertian limit (23.7 mA/cm2 and has a projected power conversion efficiency of 12.9%. Excellent solar absorption is numerically demonstrated over a broad angular range from 0 to 60 degree for both S- and P- polarizations. For the corresponding CH(NH22PbI3 based perovskite solar cell, with absorption range of 300 nm to 850 nm, we find a MAPD of 29.1 mA/cm2, corresponding to 95.4% of the total available photocurrent. The projected power conversion efficiency of the CH(NH22PbI3 based photonic crystal solar cell is 23.4%, well above the current world record efficiency of 20.1%.

  12. Light-trapping in perovskite solar cells

    Science.gov (United States)

    Du, Qing Guo; Shen, Guansheng; John, Sajeev

    2016-06-01

    We numerically demonstrate enhanced light harvesting efficiency in both CH3NH3PbI3 and CH(NH2)2PbI3-based perovskite solar cells using inverted vertical-cone photonic-crystal nanostructures. For CH3NH3PbI3 perovskite solar cells, the maximum achievable photocurrent density (MAPD) reaches 25.1 mA/cm2, corresponding to 92% of the total available photocurrent in the absorption range of 300 nm to 800 nm. Our cell shows 6% absorption enhancement compared to the Lambertian limit (23.7 mA/cm2) and has a projected power conversion efficiency of 12.9%. Excellent solar absorption is numerically demonstrated over a broad angular range from 0 to 60 degree for both S- and P- polarizations. For the corresponding CH(NH2)2PbI3 based perovskite solar cell, with absorption range of 300 nm to 850 nm, we find a MAPD of 29.1 mA/cm2, corresponding to 95.4% of the total available photocurrent. The projected power conversion efficiency of the CH(NH2)2PbI3 based photonic crystal solar cell is 23.4%, well above the current world record efficiency of 20.1%.

  13. Microbial solar cells: applying photosynthetic and electrochemically active organisms

    NARCIS (Netherlands)

    Strik, D.P.B.T.B.; Timmers, R.A.; Helder, M.; Steinbusch, K.J.J.; Hamelers, H.V.M.; Buisman, C.J.N.

    2011-01-01

    Microbial solar cells (MSCs) are recently developed technologies that utilize solar energy to produce electricity or chemicals. MSCs use photoautotrophic microorganisms or higher plants to harvest solar energy, and use electrochemically active microorganisms in the bioelectrochemical system to gener

  14. Solar heating of GaAs nanowire solar cells.

    Science.gov (United States)

    Wu, Shao-Hua; Povinelli, Michelle L

    2015-11-30

    We use a coupled thermal-optical approach to model the operating temperature rise in GaAs nanowire solar cells. We find that despite more highly concentrated light absorption and lower thermal conductivity, the overall temperature rise in a nanowire structure is no higher than in a planar structure. Moreover, coating the nanowires with a transparent polymer can increase the radiative cooling power by 2.2 times, lowering the operating temperature by nearly 7 K. PMID:26698787

  15. Solar heating of GaAs nanowire solar cells.

    Science.gov (United States)

    Wu, Shao-Hua; Povinelli, Michelle L

    2015-11-30

    We use a coupled thermal-optical approach to model the operating temperature rise in GaAs nanowire solar cells. We find that despite more highly concentrated light absorption and lower thermal conductivity, the overall temperature rise in a nanowire structure is no higher than in a planar structure. Moreover, coating the nanowires with a transparent polymer can increase the radiative cooling power by 2.2 times, lowering the operating temperature by nearly 7 K.

  16. Quantum-Tuned Multijunction Solar Cells

    Science.gov (United States)

    Koleilat, Ghada I.

    Multijunction solar cells made from a combination of CQDs of differing sizes and thus bandgaps are a promising means by which to increase the energy harvested from the Sun's broad spectrum. In this dissertation, we first report the systematic engineering of 1.6 eV PbS CQD solar cells, optimal as the front cell responsible for visible wavelength harvesting in tandem photovoltaics. We rationally optimize each of the device's collecting electrodes---the heterointerface with electron accepting TiO2 and the deep-work-function hole-collecting MoO3 for ohmic contact---for maximum efficiency. Room-temperature processing enables flexible substrates, and permits tandem solar cells that integrate a small-bandgap back cell atop a low thermal-budget larger-bandgap front cell. We report an electrode strategy that enables a depleted heterojunction CQD PV device to be fabricated entirely at room temperature. We develop a two-layer donor-supply electrode (DSE) in which a highly doped, shallow work function layer supplies a high density of free electrons to an ultrathin TiO2 layer via charge-transfer doping. Using the DSE we build all-room-temperature-processed small-bandgap (1 eV) colloidal quantum dot solar cells suitable for use as the back junction in tandem solar cells. We further report in this work the first efficient CQD tandem solar cells. We use a graded recombination layer (GRL) to provide a progression of work functions from the hole-accepting electrode in the bottom cell to the electron-accepting electrode in the top cell. The recombination layers must allow the hole current from one cell to recombine, with high efficiency and low voltage loss, with the electron current from the next cell. We conclude our dissertation by presenting the generalized conditions for design of efficient graded recombination layer solar devices. We demonstrate a family of new GRL designs experimentally and highlight the benefits of the progression of dopings and work functions in the

  17. Thin Film CIGS and CdTe Photovoltaic Technologies: Commercialization, Critical Issues, and Applications; Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Ullal, H. S.; von Roedern, B.

    2007-09-01

    We report here on the major commercialization aspects of thin-film photovoltaic (PV) technologies based on CIGS and CdTe (a-Si and thin-Si are also reported for completeness on the status of thin-film PV). Worldwide silicon (Si) based PV technologies continues to dominate at more than 94% of the market share, with the share of thin-film PV at less than 6%. However, the market share for thin-film PV in the United States continues to grow rapidly over the past several years and in CY 2006, they had a substantial contribution of about 44%, compared to less than 10% in CY 2003. In CY 2007, thin-film PV market share is expected to surpass that of Si technology in the United States. Worldwide estimated projections for CY 2010 are that thin-film PV production capacity will be more than 3700 MW. A 40-MW thin-film CdTe solar field is currently being installed in Saxony, Germany, and will be completed in early CY 2009. The total project cost is Euro 130 million, which equates to an installed PV system price of Euro 3.25/-watt averaged over the entire solar project. This is the lowest price for any installed PV system in the world today. Critical research, development, and technology issues for thin-film CIGS and CdTe are also elucidated in this paper.

  18. Chapter 10: CPV Multijunction Solar Cell Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Osterwald, Carl R.; Siefer, Gerald

    2016-04-15

    Characterization of solar cells can be divided into two types: the first is measurement of electrooptical semiconductor device parameters, and the second is determination of electrical conversion efficiency. This chapter reviews the multijunction concepts that are necessary for understanding Concentrator photovoltaic (CPV) cell characterization techniques, and describes how CPV efficiency is defined and used. For any I-V measurement of a multijunction cell, the sun simulator spectrum has to be adjusted in a way that all junctions generate the same photocurrent ratios with respect to each other as under reference conditions. The chapter discusses several procedures for spectral irradiance adjustments of solar simulators, essential for multijunction measurements. It overviews the light sources and optics commonly used in simulators for CPV cells under concentration. Finally, the chapter talks about the cell area, quantum efficiency (QE), and current-voltage (I-V) curve measurements that are needed to characterize cells as a function of irradiance.

  19. 薄膜太阳电池研究综述%Review of Thin Film Solar Cells

    Institute of Scientific and Technical Information of China (English)

    蔺旭鹏; 强颖怀; 肖裕鹏; 徐明磊

    2012-01-01

    The thin film solar cell is one of the most promising new energy sources, which provides a new and feasible way to relieve energy crisis and protect human living environment. The latest progress of several materials for fabricating thin film solar cells are reviewed, which contains silicon-based thin films (α-silicon, poly-silicon), multi-compound (CdTe, CIS, CIGS, CZTS) , organic thin film and dye-sensitized solar cells and so on. The advantages and shortcomings of the thin films such as the cost and conversion efficiency are analyzed, respectively. For lowering the cost and improving efficiency more effectively, continuous innovation of new technology and new structure should be the development tendency of the thin film solar cells.%薄膜太阳电池是最具发展潜力的新型能源之一,对缓解能源危机、保护人类生存环境提供了一种新的切实可行的方法.综述了目前国际上研究较多的几种薄膜太阳电池的最新进展,包括硅基薄膜(非晶硅、多晶硅)、多元化合物类(碲化镉、铜铟硒、铜铟镓硒、铜锌锡硫等)、有机薄膜太阳电池以及染料敏化太阳电池等.分析并总结了其在成本、转换效率等方面的优劣.为更有效地降低成本及提高电池效率,新技术、新结构的不断创新应该是未来薄膜太阳电池的发展趋势.

  20. Hybrid solar cell on a carbon fiber

    Science.gov (United States)

    Grynko, Dmytro A.; Fedoryak, Alexander N.; Smertenko, Petro S.; Dimitriev, Oleg P.; Ogurtsov, Nikolay A.; Pud, Alexander A.

    2016-05-01

    In this work, a method to assemble nanoscale hybrid solar cells in the form of a brush of radially oriented CdS nanowire crystals around a single carbon fiber is demonstrated for the first time. A solar cell was assembled on a carbon fiber with a diameter of ~5-10 μm which served as a core electrode; inorganic CdS nanowire crystals and organic dye or polymer layers were successively deposited on the carbon fiber as active components resulting in a core-shell photovoltaic structure. Polymer, dye-sensitized, and inverted solar cells have been prepared and compared with their analogues made on the flat indium-tin oxide electrode.

  1. A special issue on solar cells

    Institute of Scientific and Technical Information of China (English)

    Yi-Bing CHENG

    2011-01-01

    @@ The increasing demand for renewable energy has made the solar cell technology as one of the most significantresearch and development areas of today.Silicon based solar cells are the dominant photovoltaic products at the present time, but the relatively high costs are barriers for their broad applications.Research has been active worldwide in developing other photovoltaic technologies that use cheap materials and can be easily manufactured.Organic solar cells have attracted a lot of interests recently due to their potential to be low cost photovoltaic technologies.This special issue of the Frontiers of Optoelectronics in China has collected research articles by a number of Chinese and international experts.It is aimed to broaden the readers' view about some of the recent developments and challenges in this important R&D field.Thirteen excellent papers are in this special issue including 4 review articles and 9 research articles.

  2. Thin-film solar cells. Duennschichtsolarzellen

    Energy Technology Data Exchange (ETDEWEB)

    Bloss, W.H.; Pfisterer, F.; Schock, H.W. (Stuttgart Univ. (Germany, F.R.). Inst. fuer Physikalische Elektronik)

    1990-01-01

    The authors present the state of the art in research and development, technology, production and marketing, and of the prospects of thin-film solar cells. Thin-film solar cells most used at present are based on amorphous silicon and on the compound semiconductors CuInSe{sub 2} and CdTe. Efficiencies in excess 12% have been achieved (14.1% with CuInSe{sub 2}). Stability is the main problem with amorphous silicon. Thin-film solar cells made from compound semiconductors do not have this problem, though their cost-effective series production needs to be shown still. The development potential of the three types mentioned will be ca. 30% in terms of efficiency: in terms of production cost, it is estimated with some certainty to be able to reach the baseline of 1 DM/Watt peak output (W{sub p}). (orig.).

  3. Hybrid solar cell on a carbon fiber.

    Science.gov (United States)

    Grynko, Dmytro A; Fedoryak, Alexander N; Smertenko, Petro S; Dimitriev, Oleg P; Ogurtsov, Nikolay A; Pud, Alexander A

    2016-12-01

    In this work, a method to assemble nanoscale hybrid solar cells in the form of a brush of radially oriented CdS nanowire crystals around a single carbon fiber is demonstrated for the first time. A solar cell was assembled on a carbon fiber with a diameter of ~5-10 μm which served as a core electrode; inorganic CdS nanowire crystals and organic dye or polymer layers were successively deposited on the carbon fiber as active components resulting in a core-shell photovoltaic structure. Polymer, dye-sensitized, and inverted solar cells have been prepared and compared with their analogues made on the flat indium-tin oxide electrode. PMID:27216603

  4. Stability Issues on Perovskite Solar Cells

    Directory of Open Access Journals (Sweden)

    Xing Zhao

    2015-11-01

    Full Text Available Organo lead halide perovskite materials like methylammonium lead iodide (CH3NH3PbI3 and formamidinium lead iodide (HC(NH22PbI3 show superb opto-electronic properties. Based on these perovskite light absorbers, power conversion efficiencies of the perovskite solar cells employing hole transporting layers have increased from 9.7% to 20.1% within just three years. Thus, it is apparent that perovskite solar cell is a promising next generation photovoltaic technology. However, the unstable nature of perovskite was observed when exposing it to continuous illumination, moisture and high temperature, impeding the commercial development in the long run and thus becoming the main issue that needs to be solved urgently. Here, we discuss the factors affecting instability of perovskite and give some perspectives about further enhancement of stability of perovskite solar cell.

  5. Fabricating solar cells with silicon nanoparticles

    Science.gov (United States)

    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.

  6. Towards upconversion for amorphous silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    de Wild, J.; Rath, J.K.; Schropp, R.E.I. [Utrecht University, Faculty of Science, Debye Institute for Nanomaterials Science, Nanophotonics, P.O. Box 80000, 3508 TA Utrecht (Netherlands); Meijerink, A. [Utrecht University, Faculty of Science, Debye Institute for Nanomaterials Science, Condensed Matter and Interfaces, P.O. Box 80000, 3508 TA Utrecht (Netherlands); van Sark, W.G.J.H.M. [Utrecht University, Copernicus Institute for Sustainable Development and Innovation, Science, Technology and Society, Heidelberglaan 2, 3584 CS Utrecht (Netherlands)

    2010-11-15

    Upconversion of subbandgap light of thin film single junction amorphous silicon solar cells may enhance their performance in the near infrared (NIR). In this paper we report on the application of the NIR-vis upconverter {beta}-NaYF{sub 4}:Yb{sup 3+}(18%) Er{sup 3+}(2%) at the back of an amorphous silicon solar cell in combination with a white back reflector and its response to infrared irradiation. Current-voltage measurements and spectral response measurements were done on experimental solar cells. An enhancement of 10 {mu}A/cm{sup 2} was measured under illumination with a 980 nm diode laser (10 mW). A part of this was due to defect absorption in localized states of the amorphous silicon. (author)

  7. Recent progress on microcrystalline solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Shah, A.; Meier, J.; Torres, P.; Kroll, U.; Fischer, D.; Beck, N.; Wyrsch, N.; Keppner, H. [Univ. of Neuchatel (Switzerland). Inst. of Microtechnology

    1997-12-31

    The most important features of microcrystalline silicon ({micro}c-Si:H) and microcrystalline silicon based p-i-n solar cells (specially those deposited by VHF-Glow Discharge) are reviewed. Since such material has been recognized to be a photovoltaically active material, stabilized cell efficiencies have steadily risen and have now reached 12% in the so called micromorph (microcrystalline/amorphous) tandem cell configuration.

  8. Dual-Layer Nanostructured Flexible Thin-Film Amorphous Silicon Solar Cells with Enhanced Light Harvesting and Photoelectric Conversion Efficiency.

    Science.gov (United States)

    Lin, Yinyue; Xu, Zhen; Yu, Dongliang; Lu, Linfeng; Yin, Min; Tavakoli, Mohammad Mahdi; Chen, Xiaoyuan; Hao, Yuying; Fan, Zhiyong; Cui, Yanxia; Li, Dongdong

    2016-05-01

    Three-dimensional (3-D) structures have triggered tremendous interest for thin-film solar cells since they can dramatically reduce the material usage and incident light reflection. However, the high aspect ratio feature of some 3-D structures leads to deterioration of internal electric field and carrier collection capability, which reduces device power conversion efficiency (PCE). Here, we report high performance flexible thin-film amorphous silicon solar cells with a unique and effective light trapping scheme. In this device structure, a polymer nanopillar membrane is attached on top of a device, which benefits broadband and omnidirectional performances, and a 3-D nanostructure with shallow dent arrays underneath serves as a back reflector on flexible titanium (Ti) foil resulting in an increased optical path length by exciting hybrid optical modes. The efficient light management results in 42.7% and 41.7% remarkable improvements of short-circuit current density and overall efficiency, respectively. Meanwhile, an excellent flexibility has been achieved as PCE remains 97.6% of the initial efficiency even after 10 000 bending cycles. This unique device structure can also be duplicated for other flexible photovoltaic devices based on different active materials such as CdTe, Cu(In,Ga)Se2 (CIGS), organohalide lead perovskites, and so forth. PMID:27052357

  9. Questionable effects of antireflective coatings on inefficiently cooled solar cells

    DEFF Research Database (Denmark)

    Akhmatov, Vladislav; Galster, Georg; Larsen, Esben

    1998-01-01

    of the output power and efficiency curves throughout the day the coherence between technical parameters of the solar cells and the climate in the operation region is observed and examined. It is shown how the drop in output power around noon can be avoided by fitting technical parameters of the solar cells......A model for temperature effects in p-n junction solar cells is introduced. The temperature of solar cells and the losses in the solar cell junction region caused by elevating temperature are discussed. The model developed is examined for low-cost silicon solar cells. In order to improve the shape...

  10. Photovoltage analysis of a heterojunction solar cell

    Institute of Scientific and Technical Information of China (English)

    Xiong Chao; Yao Ruo-He; Geng Kui-Wei

    2011-01-01

    According to the p-n junction model of Shockley, the relationship between the equilibrium carrier concentrations of n-type and p-type semiconductors on the edges of the depletion region of a p-n junction solar cell is analysed. The calculation results show that the photovoltage can exceed the built-in voltage for a special kind of heterojunction solar cell. When the photovoltage exceeds the built-in voltage under illumination, the dark current and the photocurrent are impeded by the peak of voltage barrier at the interface and the expression of the total Ⅰ-Ⅴ characteristic is given.

  11. Modeling light trapping in nanostructured solar cells.

    Science.gov (United States)

    Ferry, Vivian E; Polman, Albert; Atwater, Harry A

    2011-12-27

    The integration of nanophotonic and plasmonic structures with solar cells offers the ability to control and confine light in nanoscale dimensions. These nanostructures can be used to couple incident sunlight into both localized and guided modes, enhancing absorption while reducing the quantity of material. Here we use electromagnetic modeling to study the resonances in a solar cell containing both plasmonic metal back contacts and nanostructured semiconductor top contacts, identify the local and guided modes contributing to enhanced absorption, and optimize the design. We then study the role of the different interfaces and show that Al is a viable plasmonic back contact material.

  12. Stability Issues on Perovskite Solar Cells

    OpenAIRE

    Xing Zhao; Nam-Gyu Park

    2015-01-01

    Organo lead halide perovskite materials like methylammonium lead iodide (CH3NH3PbI3) and formamidinium lead iodide (HC(NH2)2PbI3) show superb opto-electronic properties. Based on these perovskite light absorbers, power conversion efficiencies of the perovskite solar cells employing hole transporting layers have increased from 9.7% to 20.1% within just three years. Thus, it is apparent that perovskite solar cell is a promising next generation photovoltaic technology. However, the unstable natu...

  13. High performance polymer tandem solar cell

    Science.gov (United States)

    da Silva, Wilson Jose; Schneider, Fabio Kurt; Mohd Yusoff, Abd. Rashid Bin; Jang, Jin

    2015-12-01

    A power conversion efficiency of 9.02% is obtained for a fully solution-processed polymer tandem solar cell, based on the diketopyrrolopyrrole unit polymer as a low bandgap photoactive material in the rear subcell, in conjunction with a new robust interconnecting layer. This interconnecting layer is optically transparent, electrically conductive, and physically strong, thus, the charges can be collected and recombined in the interconnecting layer under illumination, while the charge is generated and extracted under dark conditions. This indicates that careful interface engineering of the charge-carrier transport layer is a useful approach to further improve the performance of polymer tandem solar cells.

  14. Kesterite Deposited by Spray Pyrolysis for Solar Cell Applications

    OpenAIRE

    Espindola Rodriguez, Moises

    2015-01-01

    Solar cells generate electrical power by direct conversion of solar radiation into electricity using semiconductors. Once produced, the solar cells do not require the use of water; operate in silence and can be easily installed almost everywhere, as solar panels with low technological risk. In this thesis new photovoltaic materials and solar cells are investigated. From the beginning of the semiconductor era, silicon has been present; the semiconductor theory improved with the silicon tec...

  15. To Enhance Performance of Light Soaking Process on ZnS/CuIn1-xGaxSe2 Solar Cell

    Directory of Open Access Journals (Sweden)

    Yu-Jen Hsiao

    2013-01-01

    Full Text Available The ZnS/CuInGaSe2 heterojunction solar cell fabricated on Mo coated glass is studied. The crystallinity of the CIGS absorber layer is prepared by coevaporated method and the ZnS buffer layer with a band gap of 3.21 eV. The MoS2 phase was also found in the CuInGaSe2/Mo system form HRTEM. The light soaking effect of photoactive film for 10 min results in an increase in F.F. from 55.8 to 64%, but series resistivity from 7.4 to 3.8 Ω. The efficiency of the devices improved from 8.12 to 9.50%.

  16. Development of Inorganic Solar Cells by Nano-technology

    Institute of Scientific and Technical Information of China (English)

    Yafei Zhang; HueyLiang Hwang; Huijuan Geng; Zhihua Zhou; Jiang Wu; Zhiming Wang; Yaozhong Zhang; Zhongli Li; Liying Zhang; Zhi Yang

    2012-01-01

    Inorganic solar cells, as durable photovoltaic devices for harvesting electric energy from sun light, have received tremendous attention due to the fear of exhausting the earth’s energy resources and damaging the living environment due to greenhouse gases. Some recent developments in nanotechnology have opened up new avenues for more relevant inorganic solar cells produced by new photovoltaic conversion concepts and effective solar energy harvesting nanostructures. In this review, the multiple exciton generation effect solar cells, hot carrier solar cells, one dimensional material constructed asymmetrical schottky barrier arrays, noble nanoparticle induced plasmonic enhancement, and light trapping nanostructured semiconductor solar cells are highlighted.

  17. Assessing Rare Metal Availability Challenges for Solar Energy Technologies

    Directory of Open Access Journals (Sweden)

    Leena Grandell

    2015-08-01

    Full Text Available Solar energy is commonly seen as a future energy source with significant potential. Ruthenium, gallium, indium and several other rare elements are common and vital components of many solar energy technologies, including dye-sensitized solar cells, CIGS cells and various artificial photosynthesis approaches. This study surveys solar energy technologies and their reliance on rare metals such as indium, gallium, and ruthenium. Several of these rare materials do not occur as primary ores, and are found as byproducts associated with primary base metal ores. This will have an impact on future production trends and the availability for various applications. In addition, the geological reserves of many vital metals are scarce and severely limit the potential of certain solar energy technologies. It is the conclusion of this study that certain solar energy concepts are unrealistic in terms of achieving TW scales.

  18. CIGS P1, P2, P3 Scribing Processes using a Pulse Programmable Industrial Fiber Laser: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Rekow, M.; Murison, R.; Panarello, T.; Dunsky, C.; Dinkel, C.; Nikumb, S.; Pern, F. J.; Mansfield, L.

    2010-10-01

    We describe a novel set of laser processes for the CIGS P1, P2 and P3 scribing steps, the development of which has been enabled by a unique pulse-programmable fiber laser. We find that the unique pulse control properties of this 1064 nm wavelength laser have significant effects on the material removal dynamics of the various film layers in the CIGS material system. In the case of the P2 and P3 processes, the shaped pulses create new laser/material interaction effects that permit the material to be cleanly and precisely removed with zero Heat Affected Zone (HAZ) at the edges of the scribe. The new P2 and P3 processes we describe demonstrate the first use of infrared nanosecond laser pulses that eliminate the HAZ and the consequent localized compositional changes in the CIGS absorber material that result in poor shunt resistance. SEM micrographs and EDX compositional scans are presented. For the P1 scribe, we process the bi-layer molybdenum from the film side as well as through the glass substrate. Microscopic inspection and compositional analysis of the scribe lines are not sufficient to determine electrical and optical performance in working PV modules. Therefore, to demonstrate the applicability of the infrared pulse-programmable laser to all three scribing processes for thin-film CIGS, we fabricate small-size multiple-cell monolithically interconnected mini-modules in partnership with the National Renewable Energy Laboratory (Golden, Colorado). A total of four mini-modules are produced, two utilizing all laser scribing, and two with the P2 and P3 steps mechanically scribed (by a third party) for reference. Mini-module performance data measured at NREL is presented, and we also discuss the commercialization potential of the new single-laser CIGS scribing process. Finally we present a phenomenological model to describe this physics underlying this novel ablation process.

  19. FY 2000 report on the results of the development of technology for commercialization of the photovoltaic power system - Development of production technology of thin film solar cells. Separate Volume 1. Development of production technology of low cost/large area modules (Investigational study on the commercialization analysis); 2000 nendo New sunshine keikaku seika hokokusho. Taiyoko hatsuden system jitsuyoka gijutsu kaihatsu {sup H}akumaku taiyodenchi no seizo gijutsu kaihatsu{sup -} Tei cost dai menseki mojuru seizo gijutsu kaihatsu (Jitsuyoka kaiseki ni kansuru chosa kenkyu) - 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    For the purpose of supporting the study of commercialization of thin film solar cells for electric power use and the study of production technology of thin film solar cells, survey of the technical trend of the thin film solar cell was conducted, and the FY 2000 results were summed up. The typical Si system thin film solar cell is the amorphous Si solar cell, and the quantity production has already started in Japan and abroad. Further, with the aim of making use of characteristics of the amorphous Si solar cell and also making its defects up, the development of Si thin film solar cell using microcrystal Si and polycrystal Si is greatly expected. Among those, attention is paid to the hybrid type that was proposed for the remarkable improvement in the conversion efficiency of amorphous Si solar cell. In the compound thin film system, the Cu(InGa)Se{sub 2}(CiGS) solar cell was put on the market as product by SSI, though the market scale is small. Further, as to the CdTe thin film solar cell, trial manufacture of the large area module was made in view of the housing use. In addition, there was seen great progress in the color sensitized cell and organic semiconducting solar cell mainly in the U.S. and Europe. (NEDO)

  20. Microcrystalline silicon and micromorph tandem solar cells

    Science.gov (United States)

    Keppner, H.; Meier, J.; Torres, P.; Fischer, D.; Shah, A.

    ``Micromorph'' tandem solar cells consisting of a microcrystalline silicon bottom cell and an amorphous silicon top cell are considered as one of the most promising new thin-film silicon solar-cell concepts. Their promise lies in the hope of simultaneously achieving high conversion efficiencies at relatively low manufacturing costs. The concept was introduced by IMT Neuchâtel, based on the VHF-GD (very high frequency glow discharge) deposition method. The key element of the micromorph cell is the hydrogenated microcrystalline silicon bottom cell that opens new perspectives for low-temperature thin-film crystalline silicon technology. According to our present physical understanding microcrystalline silicon can be considered to be much more complex and very different from an ideal isotropic semiconductor. So far, stabilized efficiencies of about 12% (10.7% independently confirmed) could be obtained with micromorph solar cells. The scope of this paper is to emphasize two aspects: the first one is the complexity and the variety of microcrystalline silicon. The second aspect is to point out that the deposition parameter space is very large and mainly unexploited. Nevertheless, the results obtained are very encouraging and confirm that the micromorph concept has the potential to come close to the required performance criteria concerning price and efficiency.

  1. Microcrystalline silicon and micromorph tandem solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Keppner, H. [Univ. of Appl. Sci., Le Locle (Switzerland); Meier, J.; Torres, P.; Fischer, D.; Shah, A. [Institute of Microtechnology, University of Neuchatel, A.-L. Breguet 2, CH-2000 Neuchatel (Switzerland)

    1999-08-01

    ``Micromorph`` tandem solar cells consisting of a microcrystalline silicon bottom cell and an amorphous silicon top cell are considered as one of the most promising new thin-film silicon solar-cell concepts. Their promise lies in the hope of simultaneously achieving high conversion efficiencies at relatively low manufacturing costs. The concept was introduced by IMT Neuchatel, based on the VHF-GD (very high frequency glow discharge) deposition method. The key element of the micromorph cell is the hydrogenated microcrystalline silicon bottom cell that opens new perspectives for low-temperature thin-film crystalline silicon technology. According to our present physical understanding microcrystalline silicon can be considered to be much more complex and very different from an ideal isotropic semiconductor. So far, stabilized efficiencies of about 12% (10.7% independently confirmed) could be obtained with micromorph solar cells. The scope of this paper is to emphasize two aspects: the first one is the complexity and the variety of microcrystalline silicon. The second aspect is to point out that the deposition parameter space is very large and mainly unexploited. Nevertheless, the results obtained are very encouraging and confirm that the micromorph concept has the potential to come close to the required performance criteria concerning price and efficiency. (orig.) With 13 figs., 2 tabs., 62 refs.

  2. Calculation of the Performance of Solar Cells With Spectral Down Shifters Using Realistic Outdoor Solar Spectra

    NARCIS (Netherlands)

    van Sark, W.G.J.H.M.

    2007-01-01

    Spectral down converters and shifters have been proposed as a good means to enhance the efficiency of underlying solar cells. In this paper, we focus on the simulation of the outdoor performance of solar cells with spectral down shifters, i.e., multicrystalline silicon solar cells with semiconductor

  3. Hybrid Silicon Nanocone–Polymer Solar Cells

    KAUST Repository

    Jeong, Sangmoo

    2012-06-13

    Recently, hybrid Si/organic solar cells have been studied for low-cost Si photovoltaic devices because the Schottky junction between the Si and organic material can be formed by solution processes at a low temperature. In this study, we demonstrate a hybrid solar cell composed of Si nanocones and conductive polymer. The optimal nanocone structure with an aspect ratio (height/diameter of a nanocone) less than two allowed for conformal polymer surface coverage via spin-coating while also providing both excellent antireflection and light trapping properties. The uniform heterojunction over the nanocones with enhanced light absorption resulted in a power conversion efficiency above 11%. Based on our simulation study, the optimal nanocone structures for a 10 μm thick Si solar cell can achieve a short-circuit current density, up to 39.1 mA/cm 2, which is very close to the theoretical limit. With very thin material and inexpensive processing, hybrid Si nanocone/polymer solar cells are promising as an economically viable alternative energy solution. © 2012 American Chemical Society.

  4. Baselines for Lifetime of Organic Solar Cells

    DEFF Research Database (Denmark)

    Gevorgyan, Suren; Espinosa Martinez, Nieves; Ciammaruchi, Laura;

    2016-01-01

    The process of accurately gauging lifetime improvements in organic photovoltaics (OPVs) or other similar emerging technologies, such as perovskites solar cells is still a major challenge. The presented work is part of a larger effort of developing a worldwide database of lifetimes that can help...

  5. Stability and Degradation of Polymer Solar cells

    DEFF Research Database (Denmark)

    Norrman, Kion

    The current state-of-the-art allows for roll-to-roll manufacture of polymer solar cells in high volume with stability and efficiency sufficient to grant success in low-energy applications. However, further improvement is needed for the successful application of the devices in real life applications...

  6. Screen printed interdigitated back contact solar cell

    Science.gov (United States)

    Baraona, C. R.; Mazaris, G. A.; Chai, A. T. (Inventor)

    1984-01-01

    Interdigitated back contact solar cells are made by screen printing dopant materials onto the back surface of a semiconductor substrate in a pair of interdigitated patterns. These dopant materials are then diffused into the substrate to form junctions having configurations corresponding to these patterns. Contacts having configurations which match the patterns are then applied over the junctions.

  7. Photochromic dye-sensitized solar cells

    Directory of Open Access Journals (Sweden)

    Noah M. Johnson

    2015-11-01

    Full Text Available We report the fabrication and characterization of photochromic dye sensitized solar cells that possess the ability to change color depending on external lighting conditions. This device can be used as a “smart” window shade that tints, collects the sun's energy, and blocks sunlight when the sun shines, and is completely transparent at night.

  8. Distributed series resistance effects in solar cells

    DEFF Research Database (Denmark)

    Nielsen, Lars Drud

    1982-01-01

    A mathematical treatment is presented of the effects of one-dimensional distributed series resistance in solar cells. A general perturbation theory is developed, including consistently the induced spatial variation of diode current density and leading to a first-order equivalent lumped resistance...... to cause an effective doubling of the "diode quality factor."...

  9. Prepolymer Syrup for Encapsulating Solar Cells

    Science.gov (United States)

    Gupta, A.; Ingham, J. D.; Yavrouian, A. H.

    1982-01-01

    Clear polymer syrup, made by disolving n-butyl acrylate prepolymer in monomer, used to encapsulate solar cells by any of three standard processes (dipping, multiple coating, or automated machine coating). Use of cyclohexane instead of methanol/water solvent during initial polymerization stage maintains high molecular weight and raises yield of linear polymer to essentially 100 percent.

  10. Assembly jig assures reliable solar cell modules

    Science.gov (United States)

    Ofarrell, H. O.

    1966-01-01

    Assembly jig holds the components for a solar cell module in place as the assembly is soldered and bonded by the even heat of an oven. The jig is designed to the configuration of the planned module. It eliminates uneven thermal conditions caused by hand soldering methods.

  11. Hot electron plasmon-protected solar cell.

    Science.gov (United States)

    Kong, J; Rose, A H; Yang, C; Wu, X; Merlo, J M; Burns, M J; Naughton, M J; Kempa, K

    2015-09-21

    A solar cell based on a hot electron plasmon protection effect is proposed and made plausible by simulations, non-local modeling of the response, and quantum mechanical calculations. In this cell, a thin-film, plasmonic metamaterial structure acts as both an efficient photon absorber in the visible frequency range and a plasmonic resonator in the IR range, the latter of which absorbs and protects against phonon emission the free energy of the hot electrons in an adjacent semiconductor junction. We show that in this structure, electron-plasmon scattering is much more efficient than electron-phonon scattering in cooling-off hot electrons, and the plasmon-stored energy is recoverable as an additional cell voltage. The proposed structure could become a prototype of a new generation of high efficiency solar cells. PMID:26406739

  12. Diketopyrrolopyrrole Polymers for Organic Solar Cells.

    Science.gov (United States)

    Li, Weiwei; Hendriks, Koen H; Wienk, Martijn M; Janssen, René A J

    2016-01-19

    Conjugated polymers have been extensively studied for application in organic solar cells. In designing new polymers, particular attention has been given to tuning the absorption spectrum, molecular energy levels, crystallinity, and charge carrier mobility to enhance performance. As a result, the power conversion efficiencies (PCEs) of solar cells based on conjugated polymers as electron donor and fullerene derivatives as electron acceptor have exceeded 10% in single-junction and 11% in multijunction devices. Despite these efforts, it is notoriously difficult to establish thorough structure-property relationships that will be required to further optimize existing high-performance polymers to their intrinsic limits. In this Account, we highlight progress on the development and our understanding of diketopyrrolopyrrole (DPP) based conjugated polymers for polymer solar cells. The DPP moiety is strongly electron withdrawing and its polar nature enhances the tendency of DPP-based polymers to crystallize. As a result, DPP-based conjugated polymers often exhibit an advantageously broad and tunable optical absorption, up to 1000 nm, and high mobilities for holes and electrons, which can result in high photocurrents and good fill factors in solar cells. Here we focus on the structural modifications applied to DPP polymers and rationalize and explain the relationships between chemical structure and organic photovoltaic performance. The DPP polymers can be tuned via their aromatic substituents, their alkyl side chains, and the nature of the π-conjugated segment linking the units along the polymer chain. We show that these building blocks work together in determining the molecular conformation, the optical properties, the charge carrier mobility, and the solubility of the polymer. We identify the latter as a decisive parameter for DPP-based organic solar cells because it regulates the diameter of the semicrystalline DPP polymer fibers that form in the photovoltaic blends with

  13. Fabrication and Characterization of Organic Solar Cells

    OpenAIRE

    Yengel, Emre

    2010-01-01

    Bulk heterojunction organic solar cells have recently drawn tremendous attention because of their technological advantages for actualization of large-area and cost effective fabrication. Two important criteria of these cells are efficiency and cost. The research in this dissertation focuses on the enhancement of these criteria with two different approaches. In the first approach, power conversion efficiency of organic photovoltaic devices is enhanced by introducing Deoxyribonucleic acids DNA ...

  14. Defect engineering in solar cell manufacturing and thin film solar cell development

    Energy Technology Data Exchange (ETDEWEB)

    Sopori, B.L. [National Renewable Energy Lab., Golden, CO (United States)

    1995-08-01

    During the last few years many defect engineering concepts were successfully applied to fabricate high efficiency silicon solar cells on low-cost substrates. Some of the research advances are described.

  15. Application of crystalline silicon solar cells in photovoltaic modules

    OpenAIRE

    L.A. Dobrzański; A. Drygała; M. Giedroć

    2010-01-01

    Purpose: The aim of the paper is to determinate basic electrical properties of solar cells, made of them photovoltaic module and analysis of its main electrical parameters.Design/methodology/approach: In this study, several methods were used: current – voltage characteristic to determinate basic electrical properties of 36 monocrystalline silicon solar cells, soft soldering technique to bond solar cells . Photovoltaic module was produced from 31 solar cells with the largest short-circuit curr...

  16. Surface Passivation Studies on n+pp+ Bifacial Solar Cell

    OpenAIRE

    Suhaila Sepeai; M. Y. Sulaiman; Kamaruzzaman Sopian; Saleem H. Zaidi

    2012-01-01

    Bifacial solar cell is a specially designed solar cell for the production of electricity from both sides of the solar cell. It is an active field of research to make photovoltaics (PV) more competitive by increasing its efficiency and lowering its costs. We developed an n+pp+ structure for the bifacial solar cell. The fabrication used phosphorus-oxy-trichloride (POCl3) diffusion to form the emitter and Al diffusion using conventional screen printing to produce the back surface field (BSF). Th...

  17. Fast Electronic Solar Cell Tester

    Science.gov (United States)

    Lathrop, J. W.; Saylor, C. R.

    1983-01-01

    Microcomputer controlled system gather current and voltage data. System consists of light source, microcomputer, programable dc power supply, analog/ digital interface, and data storage display equipment. Applies series of test loads to cell via programable dc power supply to obtain I/V characteristic curve and key cell-peformance parameter. Apparatus and programming technique are applicable to devices such as batteries and sensors.

  18. Flexible thermal cycle test equipment for concentrator solar cells

    Science.gov (United States)

    Hebert, Peter H.; Brandt, Randolph J.

    2012-06-19

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

  19. A Cost Roadmap for Silicon Heterojunction Solar Cells

    NARCIS (Netherlands)

    Louwen, A.; van Sark, W.G.J.H.M.; Schropp, Ruud; Faaij, A.

    2016-01-01

    Research and development of silicon heterojunction (SHJ) solar cells has seen a marked increase since the recent expiry of core patents describing SHJ technology. SHJ solar cells are expected to offer various cost benefits compared to conventional crystalline silicon solar cells. This paper analyses

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  1. Metal nanoparticles for thin film solar cells

    DEFF Research Database (Denmark)

    Gritti, Claudia

    Among the different renewable ways to produce energy, photovoltaic cells have a big potential and the research is now focusing on getting higher efficiency and at the same time saving the manufacturing costs improving the performance of thin film solar cells. The spectral distribution in the infr......Among the different renewable ways to produce energy, photovoltaic cells have a big potential and the research is now focusing on getting higher efficiency and at the same time saving the manufacturing costs improving the performance of thin film solar cells. The spectral distribution...... the promotion of electrons from the valence band of the semiconductor. The photoemission would extend the spectral response of the photovoltaic device. Thus, NPs are placed at the metal/semiconductor interface (in order to exploit the localization characteristic of the LSP enhancement) and are used as active...... the solar cell structure (GaAs, SiO2, Si3N4, AZO/Cr), in order to investigate the LSP resonance and tune it to exploit it below the energy band gap of the semiconductor. EBL is a difficult technique when working by lift-off on critical size (20-50 nm) nanoparticles. The optimization of the process saw...

  2. TRANSPARENT COATINGS FOR SOLAR CELLS RESEARCH

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-04-16

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

  3. Solar Airplanes and Regenerative Fuel Cells

    Science.gov (United States)

    Bents, David J.

    2007-01-01

    A solar electric aircraft with the potential to "fly forever" has captured NASA's interest, and the concept for such an aircraft was pursued under Aeronautics Environmental Research Aircraft and Sensor Technology (ERAST) project. Feasibility of this aircraft happens to depend on the successful development of solar power technologies critical to NASA's Exploration Initiatives; hence, there was widespread interest throughout NASA to bring these technologies to a flight demonstration. The most critical is an energy storage system to sustain mission power during night periods. For the solar airplane, whose flight capability is already limited by the diffuse nature of solar flux and subject to latitude and time of year constraints, the feasibility of long endurance flight depends on a storage density figure of merit better than 400-600 watt-hr per kilogram. This figure of merit is beyond the capability of present day storage technologies (other than nuclear) but may be achievable in the hydrogen-oxygen regenerative fuel cell (RFC). This potential has led NASA to undertake the practical development of a hydrogen-oxygen regenerative fuel cell, initially as solar energy storage for a high altitude UAV science platform but eventually to serve as the primary power source for NASAs lunar base and other planet surface installations. Potentially the highest storage capacity and lowest weight of any non-nuclear device, a flight-weight RFC aboard a solar-electric aircraft that is flown continuously through several successive day-night cycles will provide the most convincing demonstration that this technology's widespread potential has been realized. In 1998 NASA began development of a closed cycle hydrogen oxygen PEM RFC under the Aeronautics Environmental Research Aircraft and Sensor Technology (ERAST) project and continued its development, originally for a solar electric airplane flight, through FY2005 under the Low Emissions Alternative Power (LEAP) project. Construction of

  4. The performance of a combined solar photovoltaic (PV) and thermoelectric generator (TEG) system

    CERN Document Server

    Bjørk, R

    2015-01-01

    The performance of a combined solar photovoltaic (PV) and thermoelectric generator (TEG) system is examined using an analytical model for four different types of commercial PVs and a commercial bismuth telluride TEG. The TEG is applied directly on the back of the PV, so that the two devices have the same temperature. The PVs considered are crystalline Si (c-Si), amorphous Si (a-Si), copper indium gallium (di)selenide (CIGS) and cadmium telluride (CdTe) cells. The degradation of PV performance with temperature is shown to dominate the increase in power produced by the TEG, due to the low efficiency of the TEG. For c-Si, CIGS and CdTe PV cells the combined system produces a lower power and has a lower efficiency than the PV alone, whereas for an a-Si cell the total system performance may be slightly increased by the TEG.

  5. The performance of a combined solar photovoltaic (PV) and thermoelectric generator (TEG) system

    DEFF Research Database (Denmark)

    Bjørk, Rasmus; Nielsen, Kaspar Kirstein

    2015-01-01

    The performance of a combined solar photovoltaic (PV) and thermoelectric generator (TEG) system is examined using an analytical model for four different types of commercial PVs and a commercial bismuth telluride TEG. The TEG is applied directly on the back of the PV, so that the two devices have ...... efficiency of the TEG. For c-Si, CIGS and CdTe PV cells the combined system produces a lower power and has a lower efficiency than the PV alone, whereas for an a-Si cell the total system performance may be slightly increased by the TEG....... the same temperature. The PVs considered are crystalline Si (c-Si), amorphous Si (a-Si), copper indium gallium (di) selenide (CIGS) and cadmium telluride (CdTe) cells. The degradation of PV performance with temperature is shown to dominate the increase in power produced by the TEG, due to the low...

  6. Cu(In,Ga)Se2 and Related Solar Cells

    Science.gov (United States)

    Rau, Uwe; Schock, Hans W.

    2015-10-01

    The following sections are included: * Introduction * Material properties * Cell and module technology * Device physics * Wide-gap chalcopyrites * Kesterite (CZTS) solar cells * Conclusions * References

  7. Growth mechanism of thermally processed Cu(In,Ga)S{sub 2} precursors for printed Cu(In,Ga)(S,Se){sub 2} solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Klugius, Ines; Quintilla, Aina; Friedlmeier, Theresa M.; Blazquez-Sanchez, David; Ahlswede, Erik; Powalla, Michael [Zentrum fuer Sonnenenergie- und Wasserstoff-Forschung Baden-Wuerttemberg (ZSW), Stuttgart (Germany); Miller, Rebekah [EMD Millipore, Waltham, MA (United States)

    2012-07-15

    We investigate a process used for the selenisation of particle-based precursors to prepare low-cost Cu(In,Ga)(S,Se){sub 2} (CIGS) solar cells. It is suitable for high throughput with a short optimum selenisation duration of 3-5 min and employs a rapid thermal annealing system with elemental selenium vapour. Homogeneous crack-free Cu(In,Ga)S{sub 2} precursor films of up to 1 {mu}m are obtained via doctor blading. The high selenium vapour pressure in the selenisation reaction chamber results in the formation of a compact Cu(In,Ga)(S,Se){sub 2} layer on top of a carbon-rich underlayer. In order to investigate the phase development in the film, the selenisation process was interrupted at different stages and the samples were monitored via XRD and surface-sensitive Raman measurements. We find the formation of a polycrystalline Cu(In,Ga)Se{sub 2} phase already after 1 s at the target temperature of 550 C. Furthermore, the effect of initial precursor thickness on solar cell parameters is discussed. Complete solar cells are prepared by conventional methods, leading to conversion efficiencies well above 8%. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  8. Proton irradiation effects of amorphous silicon solar cell for solar power satellite

    Energy Technology Data Exchange (ETDEWEB)

    Morita, Yousuke; Oshima, Takeshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Sasaki, Susumu; Kuroda, Hideo; Ushirokawa, Akio

    1997-03-01

    Flexible amorphous silicon(fa-Si) solar cell module, a thin film type, is regarded as a realistic power generator for solar power satellite. The radiation resistance of fa-Si cells was investigated by the irradiations of 3,4 and 10 MeV protons. The hydrogen gas treatment of the irradiated fa-Si cells was also studied. The fa-Si cell shows high radiation resistance for proton irradiations, compared with a crystalline silicon solar cell. (author)

  9. Semiconductor Nanocrystals as Light Harvesters in Solar Cells

    Directory of Open Access Journals (Sweden)

    Lioz Etgar

    2013-02-01

    Full Text Available Photovoltaic cells use semiconductors to convert sunlight into electrical current and are regarded as a key technology for a sustainable energy supply. Quantum dot-based solar cells have shown great potential as next generation, high performance, low-cost photovoltaics due to the outstanding optoelectronic properties of quantum dots and their multiple exciton generation (MEG capability. This review focuses on QDs as light harvesters in solar cells, including different structures of QD-based solar cells, such as QD heterojunction solar cells, QD-Schottky solar cells, QD-sensitized solar cells and the recent development in organic-inorganic perovskite heterojunction solar cells. Mechanisms, procedures, advantages, disadvantages and the latest results obtained in the field are described. To summarize, a future perspective is offered.

  10. Lessons learned from NMSG-085 CIG Land Operation demonstration

    NARCIS (Netherlands)

    Gautreau, B.; Remmersmann, T.; Henderson, H.C.; Reus, N.M. de; Khimeche, L.; Pedersen, E.; Lillesoe, J.; Liberg, D.

    2013-01-01

    This paper presents the experience gained during demonstrations carried out between Denmark, France, Germany, the Netherlands and Spain under the umbrella of the NMSG-085 / CIG Land Operation group. The demonstration, also presented in this paper, focuses on command post exercise training. It highli

  11. Rational Strategies for Efficient Perovskite Solar Cells.

    Science.gov (United States)

    Seo, Jangwon; Noh, Jun Hong; Seok, Sang Il

    2016-03-15

    A long-standing dream in the large scale application of solar energy conversion is the fabrication of solar cells with high-efficiency and long-term stability at low cost. The realization of such practical goals depends on the architecture, process and key materials because solar cells are typically constructed from multilayer heterostructures of light harvesters, with electron and hole transporting layers as a major component. Recently, inorganic-organic hybrid lead halide perovskites have attracted significant attention as light absorbers for the fabrication of low-cost and high-efficiency solar cells via a solution process. This mainly stems from long-range ambipolar charge transport properties, low exciton binding energies, and suitable band gap tuning by managing the chemical composition. In our pioneering work, a new photovoltaic platform for efficient perovskite solar cells (PSCs) was proposed, which yielded a high power conversion efficiency (PCE) of 12%. The platform consisted of a pillared architecture of a three-dimensional nanocomposite of perovskites fully infiltrating mesoporous TiO2, resulting in the formation of continuous phases and perovskite domains overlaid with a polymeric hole conductor. Since then, the PCE of our PSCs has been rapidly increased from 3% to over 20% certified efficiency. The unprecedented increase in the PCE can be attributed to the effective integration of the advantageous attributes of the refined bicontinuous architecture, deposition process, and composition of perovskite materials. Specifically, the bicontinuous architectures used in the high efficiency comprise a layer of perovskite sandwiched between mesoporous metal-oxide layer, which is a very thinner than that of used in conventional dye-sensitized solar cells, and hole-conducting contact materials with a metal back contact. The mesoporous scaffold can affect the hysteresis under different scan direction in measurements of PSCs. The hysteresis also greatly depends on

  12. Optimization of multijunction solar cells through indoor energy yield measurements

    OpenAIRE

    García Vara, Iván; Mcmahon, William E.; Steiner, Myles A.; Geisz, John F.; Habte, Aron; Friedman, Daniel J.

    2015-01-01

    The variability of the solar spectra in the field may reduce the annual energy yield of multijunction solar cells. It would, therefore, be desirable to implement a cell design procedure based on the maximization of the annual energy yield. In this study, we present a measurement technique to generate maps of the real performance of the solar cell for a range of light spectrum contents using a solar simulator with a computer-controllable spectral content. These performance maps are demonstrate...

  13. Thin foil silicon solar cells with coplanar back contacts

    Science.gov (United States)

    Ho, F.; Iles, P. A.; Baraona, C. R.

    1981-01-01

    To fabricate 50 microns thick, coplanar back contact (CBC) silicon solar cells, wraparound junction design was selected and proved to be effective. The process sequence used, the cell design, and the cell performance are described. CBC cells with low solar absorptance have shown AMO efficiencies to 13%, high cells up to 14%; further improvements are projected with predictable optimization.

  14. Solar cell module. Taiyo denchi module

    Energy Technology Data Exchange (ETDEWEB)

    Nakano, Akihiko.

    1990-01-24

    This invention concerns a module frame of solar cell and a solar cell module using this frame. In particular, it concerns a frame and a module useful for the CdS/CdTe or CdS/CuInSe {sub 2} based cell. In the existing solar cell module, sealant is packed in between the edges of a glass substrate, a resin layer and a back protective thin film, etc. and a grooved frame of U-shaped section. For the sealant, silicon based resin and butyl rubber based resin are used many times, but either resin has defects such as their overflow from the module structure. In order to solve these defects, this invention proposes to provide stair-shaped protrusions along the four sides of the bottom of the box frame (herein after called the lower frame) of the module and at the same time, provide a groove for pooling the sealant at the portion where such protrusion meets the side wall, furthermore to provide depressions for pooling the sealant at the upper edge inside the side wall of the lower frame or to punch holes at the corners of the bottom of the lower frame. 9 figs.

  15. Recent advances in sensitized mesoscopic solar cells.

    Science.gov (United States)

    Grätzel, Michael

    2009-11-17

    Perhaps the largest challenge for our global society is to find ways to replace the slowly but inevitably vanishing fossil fuel supplies by renewable resources and, at the same time, avoid negative effects from the current energy system on climate, environment, and health. The quality of human life to a large degree depends upon the availability of clean energy sources. The worldwide power consumption is expected to double in the next 3 decades because of the increase in world population and the rising demand of energy in the developing countries. This implies enhanced depletion of fossil fuel reserves, leading to further aggravation of the environmental pollution. As a consequence of dwindling resources, a huge power supply gap of 14 terawatts is expected to open up by year 2050 equaling today's entire consumption, thus threatening to create a planetary emergency of gigantic dimensions. Solar energy is expected to play a crucial role as a future energy source. The sun provides about 120,000 terawatts to the earth's surface, which amounts to 6000 times the present rate of the world's energy consumption. However, capturing solar energy and converting it to electricity or chemical fuels, such as hydrogen, at low cost and using abundantly available raw materials remains a huge challenge. Chemistry is expected to make pivotal contributions to identify environmentally friendly solutions to this energy problem. One area of great promise is that of solar converters generally referred to as "organic photovoltaic cells" (OPV) that employ organic constituents for light harvesting or charge carrier transport. While this field is still in its infancy, it is receiving enormous research attention, with the number of publications growing exponentially over the past decade. The advantage of this new generation of solar cells is that they can be produced at low cost, i.e., potentially less than 1 U.S. $/peak watt. Some but not all OPV embodiments can avoid the expensive and energy

  16. Thermal test and analysis of concentrator solar cells

    Science.gov (United States)

    Cui, Min; Chen, Nuofu; Wu, Jinliang; Liu, Lei; Wang, Peng; Wang, Yanshuo; Bai, Yiming

    2008-03-01

    Under high concentration the temperature of photovoltaic solar cells is very high. It is well known that the efficiency and performance of photovoltaic solar cells decrease with the increase of temperature. So cooling is indispensable for a concentrator photovoltaic solar cell at high concentration. Usually passive cooling is widely considered in a concentrator system. However, the thermal conduction principle of concentrator solar cells under passive cooling is seldom reported. In this paper, GaInP/GaAs/Ge triple junction solar cells were fabricated using metal organic chemical vapor deposition technique. The thermal conductivity performance of monolithic concentrator GaInP/GaAs/Ge cascade solar cells under 400X concentration with a heat sink were studied by testing the surface and backside temperatures of solar cells. The tested result shows that temperature difference between both sides of the solar cells is about 1K. A theoretical model of the thermal conductivity and thermal resistance of the GaInP/GaAs/Ge triple junction solar cells was built, and the calculation temperature difference between both sides of the solar cells is about 0.724K which is consistent with the result of practical test. Combining the theoretical model and the practical testing with the upper surface temperature of tested 310K, the temperature distribution of the solar cells was researched.

  17. A Physics-based Analytical Model for Perovskite Solar Cells

    OpenAIRE

    Sun, Xingshu; Asadpour, Reza; Nie, Wanyi; Mohite, Aditya D.; Alam, Muhammad A.

    2015-01-01

    Perovskites are promising next-generation absorber materials for low-cost and high-efficiency solar cells. Although perovskite cells are configured similar to the classical solar cells, their operation is unique and requires development of a new physical model for characterization, optimization of the cells, and prediction of the panel performance. In this paper, we develop such a physics-based analytical model to describe the operation of different types of perovskite solar cells, explicitly...

  18. Highly efficient light management for perovskite solar cells

    CERN Document Server

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

    2015-01-01

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

  19. Hybrid Automatic Solar Tracking System for Different Types of Solar Cells: A review.

    OpenAIRE

    Neha Sonkar; Pankaj J Edla; Dr. Bhupendra Gupta

    2013-01-01

    The objective of this paper is to present review on the use of different material of Solar panel in a solar tracking system at Stationary, Single Axis, Dual Axis & Hybrid Axis solar tracker to have better performance with minimum losses to the surroundings, as the solar tracker ensures maximum intensity of sun rays hitting the surface of the panel from sunrise to sunset. Solar cells are playing a role of increasing importance in household and other areas of electricity consumption. Due to the...

  20. Polymer:fullerene bulk heterojunction solar cells

    Directory of Open Access Journals (Sweden)

    Jenny Nelson

    2011-10-01

    Full Text Available The efficiency of solar cells made from a conjugated polymer blended with a fullerene derivative has risen from around 1 % to over 9 % in the last ten years, making organic photovoltaic technology a viable contender for commercialization. The efficiency increases have resulted from the development of new materials with lower optical gaps, new polymer:fullerene combinations with higher charge separated state energies, and new approaches to control the blend microstructure, all driven by a qualitative understanding of the principles governing organic solar cell operation. In parallel, a device physics framework has been developed that enables the rational design of device structures and materials for improved organic photovoltaic devices. We review developments in both materials science and device physics for organic photovoltaics.

  1. Solar cell module. Taiyo denchi module

    Energy Technology Data Exchange (ETDEWEB)

    Nakano, Akihiko; Matsumoto, Hitoshi; Komatsu, Yasumitsu; Shirai, Sadaharu.

    1989-09-29

    In the solar cell module of this invention, such junctions as CdS/CdTe or CdS/CuInSe {sub 2} are contained as a photoelectromotive force part coexists with air in a closed space which consists of glass, metal parts and a bonding resin layer; the photoelectromotive force part is coated either with a fluorine resin or a silicone resin. The fluorine resin contains a fundamental skeleton of an alternative copolymer of fluoroolefin and a hydrocarbon-based vinyl monomer; the silicone resin has three types, i.e., addition-reacted, condensated or UV-curing type, and the released oxygen is sealed in the closed space. The resin layer which adheres the glass and the metal plate is a thermoplastic resin which is polyethylene modified by copolymerization of acid anhydride. By this, the reliability of the solar cell module was enhanced. 3 figs.

  2. Nanostructured upconverters for improved solar cell performance

    Science.gov (United States)

    MacQueen, Rowan W.; Schulze, Tim F.; Khoury, Tony; Cheng, Yuen Yap; Stannowski, Bernd; Lips, Klaus; Crossley, Maxwel J.; Schmidt, Timothy

    2013-09-01

    Triplet-triplet annihilation photon upconversion (TTA-UC) is a promising candidate for mitigating sub-band gap absorption losses in solar cells. In TTA-UC, sensitiser dyes absorb sub-band gap photons, cross to a triplet state, and transfer triplet excitons to emitter dyes. Two triplet-excited emitters can undergo TTA, raising one emitter to a higher-energy bright singlet state. The quadratic efficiency of TTA-UC at device-relevant light intensities motivates a push towards the higher chromophore densities achievable in the solid phase. We have begun this process by tethering tetrakisquinoxalino palladium porphyrin to 20nm silica nanoparticles using peptide chemistry techniques, achieving a total-volume concentration of 1.5mM. The phosphorescence kinetics of the tethered porphyrins was measured to quantify quenching by rubrene emitter. Upconverter performance was measured in a solar cell enhancement experiment.

  3. Optical Management Techniques for Organic Solar Cells

    CERN Document Server

    Rajagopal, Adharsh

    2016-01-01

    In this thesis, two different optical management techniques for organics based solar cells are explored. The first part is focused on the development of a textured rear reflector for OPVs. The use of textured reflector (TR) facilitates an increase in the optical path length along with light trapping within the active layer. TR was fabricated through a relatively simpler technique by depositing metal films over a microlens array (MLA). Zinc oxide nanoparticles were used to minimize the shadowing effect. Using TR, enhancements in short-circuit current density and power conversion efficiencies up to 10-25% were demonstrated for a polymer based organic solar cell. The second part is focused on improving the effectiveness of MLA incorporation in OPVs. The increase in path length achieved using MLA can be improved by increasing the refractive index of MLA and incorporating MLA directly on the transparent electrode instead of glass substrate. This approach could avoid the optical losses occurring at the interface be...

  4. A Bicontinuous Double Gyroid Hybrid Solar Cell

    KAUST Repository

    Crossland, Edward J. W.

    2009-08-12

    We report the first successful application of an ordered bicontinuous gyroid semiconducting network in a hybrid bulk heterojunction solar cell. The freestanding gyroid network is fabricated by electrochemical deposition into the 10 nm wide voided channels of a self-assembled, selectively degradable block copolymer film. The highly ordered pore structure is ideal for uniform infiltration of an organic hole transporting material, and solid-state dye-sensitized solar cells only 400 nm thick exhibit up to 1.7% power conversion efficiency. This patterning technique can be readily extended to other promising heterojunction systems and is a major step toward realizing the full potential of self-assembly in the next generation of device technologies. © 2009 American Chemical Society.

  5. Flexible ITO-Free Polymer Solar Cells

    DEFF Research Database (Denmark)

    Angmo, Dechan; Krebs, Frederik C

    2013-01-01

    Indium tin oxide (ITO) is the material-of-choice for transparent conductors in any optoelectronic application. However, scarce resources of indium and high market demand of ITO have created large price fluctuations and future supply concerns. In polymer solar cells (PSCs), ITO is the single......-most cost driving factor due to expensive raw materials and processing. Given the limited lifetime and stability of PSCs as compared with other mature technologies such as silicon-based solar cells, the technological future of PSCs beyond that of academic interests rests in reducing cost of production......-cost alternatives to ITO suitable for use in PSCs. These alternatives belong to four material groups: polymers; metal and polymer composites; metal nanowires and ultra-thin metal films; and carbon nanotubes and graphene. We further present the progress of employing these alternatives in PSCs and identify future...

  6. Organic Based Solar Cells with Morphology Control

    DEFF Research Database (Denmark)

    Andersen, Thomas Rieks

    to be addressed. Among these are a more direct transfer of new materials tested on a laboratory scale to large scale production than offered by spincoating, a method offering direct control of the morphology in the active layer, and a more environmental friendly processing, where the vast use of organic solvents...... offers a great challenge. In this thesis the development of inks with a pre-arranged morphology was attempted by two methods. First by grafting of silicon nanoparticles with an organic phenylene vinylene oligomer, the resulting particles were analyzed by 1H-NMR, absorption spectroscopy, Atomic Force...... Microscopy and as solar cells in a blend with PCBM. It was concluded that these particles did not show a potential large enough for continuous work due to a high material loss and low efficiency when applied in solar cells. The second method to achieve was preparation of pre-arranged morphology organic...

  7. Solar Cells Having a Nanostructured Antireflection Layer

    DEFF Research Database (Denmark)

    2013-01-01

    An solar cell having a surface in a first material is provided, the optical device having a non-periodic nanostructure formed in the surface, the nanostructure comprising a plurality of cone -haped structures wherein the cones are distributed non-periodically on the surface and have a random height...... distribution, at least a part of the cone-shaped structures having a height of at least 100 nm. The first material may be SiC or GaN. A method of manufacturing a non-periodic nanostructured surface on a solar cell, is furthermore provided, the method comprising the steps of providing a surface comprising Si...... a non-periodical nano structure, the nano structure comprising a plurality of cone-shaped surface structures, whereby the structures have a random height distribution, at least a part of the structures having a height of at least 100 nm....

  8. Modeling of Silicon Heterojunction Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-06-14

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

  9. Microcrystalline organic thin-film solar cells.

    Science.gov (United States)

    Verreet, Bregt; Heremans, Paul; Stesmans, Andre; Rand, Barry P

    2013-10-11

    Microcrystalline organic films with tunable thickness are produced directly on an indium-tin-oxide substrate, by crystallizing a thin amorphous rubrene film followed by its use as a template for subsequent homoepitaxial growth. These films, with exciton diffusion lengths exceeding 200 nm, produce solar cells with increasing photocurrents at thicknesses up to 400 nm with a fill factor >65%, demonstrating significant potential for microcrystalline organic electronic devices. PMID:23939936

  10. The photophysics of perovskite solar cells

    Science.gov (United States)

    Sum, Tze Chien

    2014-09-01

    Solution-processed hybrid organic-inorganic perovskite solar cells, a newcomer to the photovoltaic arena, have taken the field by storm with their extraordinary power conversion efficiencies exceeding 17%. In this paper, the photophysics and the latest findings on the carrier dynamics and charge transfer mechanisms in this new class of photovoltaic material will be examined and distilled. Some open photophysics questions will also be discussed.

  11. Transparent Electrodes for Organic Solar Cells

    OpenAIRE

    Selzer, Franz

    2016-01-01

    The aim of this work was to investigate silver nanowire as well as carbon nanotube networks as transparent conducting electrodes for small molecule organic solar cells. In the framework of the nanowire investigations, a low-temperature method at less than 80 °C is developed to obtain highly conductive networks directly after the deposition and without post-processing. In detail, specific non-conductive organic materials act as a matrix where the nanowires are embedded in such that a mutua...

  12. Recent developments in thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Dhere, N.G. (Inst. Militar de Engenharia, Rio de Janeiro, RJ (Brazil))

    1990-12-15

    In recent years, remarkable progress has been made in improving the photovoltaic (PV) conversion efficiencies of thin film solar cells. The best active-area efficiencies (air mass 1.5) of thin film solar cells reported are as follows: polycrystalline CuInSe{sub 2}, 14.1%; CuIn(Ga)Se{sub 2}, 12.9%; CdTe, 12.3%, total area; single-junction hydrogenated amorphous silicon (a-Si:H), 12.0%; multiple-junction a-Si:H, 13.3%; cleaved epitaxial GaAs-Ga{sub 1-x}Al{sub x}As, 21.5%, total area. Laboratory methods for preparing small thin film solar cells are evaporation, closed-space sublimation, closed-space vapor transport, vapor phase epitaxy and metallo-organic chemical vapor deposition, while economic large-area deposition techniques such as sputtering, glow discharge reduction, electrodeposition, spraying and screen printing are being used for module fabrication. The following aperture-area efficiencies have been measured, at the Solar Energy Research Inst., for thin film modules: a-Si:H, 9.8%, 933 cm{sup 2}; CuIn(Ga)Se{sub 2}, 11.1%, 938 cm{sup 2}; CdTe, 7.3%, 838 cm{sup 2}. The instability issue of a-Si:H continues to be a high priority area. It is necessary to improve the open-circuit voltage of CuIn(Ga)Se{sub 2} cells, which do not seem to exhibit any intrinsic degradation mechanisms. With continued progress and increased production, PV modules are likely to become competitive for medium-scale power requirements in the mid-1990s. (orig.).

  13. Plasmonic Dye-Sensitized Solar Cells

    KAUST Repository

    Ding, I-Kang

    2010-12-14

    This image presents a scanning electron microscopy image of solid state dye-sensitized solar cell with a plasmonic back reflector, overlaid with simulated field intensity plots when monochromatic light is incident on the device. Plasmonic back reflectors, which consist of 2D arrays of silver nanodomes, can enhance absorption through excitation of plasmonic modes and increased light scattering, as reported by Michael D. McGehee, Yi Cui, and co-workers.

  14. High performance polymer tandem solar cell

    OpenAIRE

    Wilson Jose da Silva; Fabio Kurt Schneider; Abd. Rashid bin Mohd Yusoff; Jin Jang

    2015-01-01

    A power conversion efficiency of 9.02% is obtained for a fully solution-processed polymer tandem solar cell, based on the diketopyrrolopyrrole unit polymer as a low bandgap photoactive material in the rear subcell, in conjunction with a new robust interconnecting layer. This interconnecting layer is optically transparent, electrically conductive, and physically strong, thus, the charges can be collected and recombined in the interconnecting layer under illumination, while the charge is genera...

  15. PbSe Nanocrystal Excitonic Solar Cells

    KAUST Repository

    Choi, Joshua J.

    2009-11-11

    We report the design, fabrication, and characterization of colloidal PbSe nanocrystal (NC)-based photovoltaic test structures that exhibit an excitonic solar cell mechanism. Charge extraction from the NC active layer is driven by a photoinduced chemical potential energy gradient at the nanostructured heterojunction. By minimizing perturbation to PbSe NC energy levels and thereby gaining insight into the "intrinsic" photovoltaic properties and charge transfer mechanism of PbSe NC, we show a direct correlation between interfacial energy level offsets and photovoltaic device performance. Size dependent PbSe NC energy levels were determined by cyclic voltammetry and optical spectroscopy and correlated to photovoltaic measurements. Photovoltaic test structures were fabricated from PbSe NC films sandwiched between layers of ZnO nanoparticles and PEDOT:PSS as electron and hole transporting elements, respectively. The device current-voltage characteristics suggest a charge separation mechanism that Is distinct from previously reported Schottky devices and consistent with signatures of excitonic solar cells. Remarkably, despite the limitation of planar junction structure, and without film thickness optimization, the best performing device shows a 1-sun power conversion efficiency of 3.4%, ranking among the highest performing NC-based solar cells reported to date. © 2009 American Chemical Society.

  16. US Polycrystalline Thin Film Solar Cells Program

    Science.gov (United States)

    Ullal, Harin S.; Zweibel, Kenneth; Mitchell, Richard L.

    1989-11-01

    The Polycrystalline Thin Film Solar Cells Program, part of the United States National Photovoltaic Program, performs R and D on copper indium diselenide and cadmium telluride thin films. The objective of the program is to support research to develop cells and modules that meet the U.S. Department of Energy's long-term goals by achieving high efficiencies (15 to 20 percent), low-cost ($50/m(sup 2)), and long-time reliability (30 years). The importance of work in this area is due to the fact that the polycrystalline thin-film CuInSe2 and CdTe solar cells and modules have made rapid advances. They have become the leading thin films for PV in terms of efficiency and stability. The U.S. Department of Energy has increased its funding through an initiative through the Solar Energy Research Institute in CuInSe2 and CdTe with subcontracts to start in spring 1990.

  17. Thin-film cadmium telluride solar cells

    Science.gov (United States)

    Chu, T. L.

    1987-10-01

    Cadmium telluride, with a room-temperature band-gap energy of 1.5 eV, is a promising thin-film photovoltaic material. The major objective of this research has been to demonstrate thin-film CdTe heterojunction solar cells with a total area greater than 1 sq cm and photovoltaic efficiencies of 13 percent or more. Thin-film p-CdTe/CdS/SnO2:F/glass solar cells with an AM1.5 efficiency of 10.5 percent have been reported previously. This report contains results of work done on: (1) the deposition, resistivity control, and characterization of p-CdTe films by the close-spaced sublimation process; (2) the deposition of large-band-gap window materials; (3) the electrical properties of CdS/CdTe heterojunctions; (4) the formation of stable, reproducible, ohmic contacts (such as p-HgTe) to p-CdTe; and (5) the preparation and evaluation of heterojunction solar cells.

  18. Machine vision for solar cell characterization

    Science.gov (United States)

    Ordaz, Miguel A.; Lush, Gregory B.

    2000-03-01

    An in-line, non-destructive process is being developed for characterizing polycrystalline thin-film and other large area electronic devices using computer vision based imaging of the manufacturing and inspection steps during the device fabrication process. This process is being applied specifically to Cadmium Telluride/Cadmium Sulfide (CdTe/CdS) thin film, polycrystalline solar cells. Our process involves the acquisition of reflective, transmission and electroluminescence (EL) intensity images for each device. The EL intensity images have been processed by use of a modified median cut segmentation. The processed images reveal different gray level regions corresponding to different intensities of EL originating from radiative recombination events occurring within a biased solar cell. Higher efficiency devices show a more uniform intensity distribution in contrast with lower efficiency devices. The uniform intensity regions are made up of gray level intensity values found near the mean of the histogram distribution these are identified as regions of good device performance and are attributed to better material quality and processing. Low intensity regions indicate either material defects or errors in processing. This novel characterization process and analysis are providing new insights into the causes of poor performance in CdTe-based solar cells.

  19. US polycrystalline thin film solar cells program

    Energy Technology Data Exchange (ETDEWEB)

    Ullal, H S; Zweibel, K; Mitchell, R L [Solar Energy Research Inst., Golden, CO (USA)

    1989-11-01

    The Polycrystalline Thin Film Solar Cells Program, part of the United States National Photovoltaic Program, performs R D on copper indium diselenide and cadmium telluride thin films. The objective of the Program is to support research to develop cells and modules that meet the US Department of Energy's long-term goals by achieving high efficiencies (15%-20%), low-cost ($50/m{sup 2}), and long-time reliability (30 years). The importance of work in this area is due to the fact that the polycrystalline thin-film CuInSe{sub 2} and CdTe solar cells and modules have made rapid advances. They have become the leading thin films for PV in terms of efficiency and stability. The US Department of Energy has increased its funding through an initiative through the Solar Energy Research Institute in CuInSe{sub 2} and CdTe with subcontracts to start in Spring 1990. 23 refs., 5 figs.

  20. Modeling Anomalous Hysteresis in Perovskite Solar Cells.

    Science.gov (United States)

    van Reenen, Stephan; Kemerink, Martijn; Snaith, Henry J

    2015-10-01

    Organic-inorganic lead halide perovskites are distinct from most other semiconductors because they exhibit characteristics of both electronic and ionic motion. Accurate understanding of the optoelectronic impact of such properties is important to fully optimize devices and be aware of any limitations of perovskite solar cells and broader optoelectronic devices. Here we use a numerical drift-diffusion model to describe device operation of perovskite solar cells. To achieve hysteresis in the modeled current-voltage characteristics, we must include both ion migration and electronic charge traps, serving as recombination centers. Trapped electronic charges recombine with oppositely charged free electronic carriers, of which the density depends on the bias-dependent ion distribution in the perovskite. Our results therefore show that reduction of either the density of mobile ionic species or carrier trapping at the perovskite interface will remove the adverse hysteresis in perovskite solar cells. This gives a clear target for ongoing research effort and unifies previously conflicting experimental observations and theories.

  1. A Microstrip Printed Dipole Solar Antenna Using Polycrystalline Silicon Solar Cells

    OpenAIRE

    Shynu, S.; Roo Ons, Maria; Ruvio, Giuseppe; Ammann, Max; MCCORMACK, SARAH; Norton, Brian

    2008-01-01

    A novel printed dipole solar antenna design with an integrated balun is proposed for the first time with high efficiency polycrystalline silicon solar cells is presented in this paper. The optimum orientation of the silver DC bus bars of the solar cell is determined in order to achieve best antenna performance. Good solar antenna performance similar to that of ordinary printed dipoles with PEC reflectors is achieved.

  2. Light management in thin-film silicon solar cells

    OpenAIRE

    Isabella, O.

    2013-01-01

    Solar energy can fulfil mankind’s energy needs and secure a more balanced distribution of primary sources of energy. Wafer-based and thin-film silicon solar cells dominate todays’ photovoltaic market because silicon is a non-toxic and abundant material and high conversion efficiencies are achieved with silicon-based solar cells. To stay competitive with bulk crystalline silicon and other thin-film solar cell technologies, thin-film silicon solar cells have to achieve a conversion efficiency l...

  3. Electricity from photovoltaic solar cells: Flat-Plate Solar Array Project final report. Volume IV: High-efficiency solar cells

    OpenAIRE

    Leipold, M.; L. Cheng; Daud, T.; Mokashi, A; Burger, D.

    1986-01-01

    The Flat-Plate Solar Array (FSA) Project, funded by the U.S. Government and managed by the Jet Propulsion Laboratory, was formed in 1975 to develop the module/array technology needed to attain widespread terrestrial use of photovoltaics by 1985. To accomplish this, the FSA Project established and managed an Industry, University, and Federal Government Team to perform the needed research and development (R&D). The High-Efficiency Solar Cells Task was assigned the objective of understandin...

  4. Trajectory-Oriented and Fault-Tolerant-Based Intelligent Process Control for Flexible CIGS PV Module Manufacturing; Final Technical Report, 13 May 2002--30 May 2005

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, L.; Britt, J.; Birkmire, R.; Vincent, T.

    2005-10-01

    ITN Energy Systems, Inc., and Global Solar Energy, Inc., assisted by NREL's PV Manufacturing R&D program, have continued to advance CIGS production technology by developing trajectory-oriented predictive/control models, fault-tolerance control, control platform development, in-situ sensors, and process improvements. Modeling activities included developing physics-based and empirical models for CIGS and sputter-deposition processing, implementing model-based control, and applying predictive models to the construction of new evaporation sources and for control. Model-based control is enabled by implementing reduced or empirical models into a control platform. Reliability improvement activities include implementing preventive maintenance schedules; detecting failed sensors/equipment and reconfiguring to tinue processing; and systematic development of fault prevention and reconfiguration strategies for the full range of CIGS PV production deposition processes. In-situ sensor development activities have resulted in improved control and indicated the potential for enhanced process status monitoring and control of the deposition processes. Substantial process improvements have been made, including significant improvement in CIGS uniformity, thickness control, efficiency, yield, and throughput. In large measure, these gains have been driven by process optimization, which in turn have been enabled by control and reliability improvements due to this PV Manufacturing R&D program.

  5. MANUFACTURE OF PHOTOVOLTAIC SOLAR CELL USING PLANT CHLOROPHYLL

    Science.gov (United States)

    To date, we have successfully manufactured working chlorophyll sensitized solar cells using chlorophyll (and b mixture) from spinach leaves. We have evaluated the electronic characteristics (voltage, current, and power outputs using different loading resistors) of this solar c...

  6. Photocurrent images of amorphous-silicon solar-cell modules

    Science.gov (United States)

    Kim, Q.; Shumka, A.; Trask, J.

    1985-01-01

    Results obtained in applying the unique characteristics of the solar cell laser scanner to investigate the defects and quality of amorphous silicon cells are presented. It is concluded that solar cell laser scanners can be effectively used to nondestructively test not only active defects but also the cell quality and integrity of electrical contacts.

  7. Thin-film silicon solar cell technology

    Energy Technology Data Exchange (ETDEWEB)

    Shah, A.V.; Meier, J.; Kroll, U.; Droz, C.; Bailat, J. [University of Neuchatel (Switzerland). Inst. of Microtechnology; Schade, H. [RWE Schott Solar GmbH, Putzbrunn (Germany); Vanecek, M. [Academy of Sciences, Prague (Czech Republic). Inst. of Physics; Vallat Sauvain, E.; Wyrsch, N. [University of Neuchatel (Switzerland). Inst. of Microtechnology; Unaxis SPTec S A, Neuchatel (Switzerland)

    2004-07-01

    This paper describes the use, within p-i-n- and n-i-p-type solar cells, of hydrogenated amorphous silicon (a-Si:H) and hydrogenated microcrystalline silicon ({mu}c-Si:H) thin films (layers), both deposited at low temperatures (200{sup o}C) by plasma-assisted chemical vapour deposition (PECVD), from a mixture of silane and hydrogen. Optical and electrical properties of the i-layers are described. These properties are linked to the microstructure and hence to the i-layer deposition rate, that in turn, affects throughput in production. The importance of contact and reflection layers in achieving low electrical and optical losses is explained, particularly for the superstrate case. Especially the required properties for the transparent conductive oxide (TCO) need to be well balanced in order to provide, at the same time, for high electrical conductivity (preferably by high electron mobility), low optical absorption and surface texture (for low optical losses and pronounced light trapping). Single-junction amorphous and microcrystalline p-i-n-type solar cells, as fabricated so far, are compared in their key parameters (J{sub sc},FF,V{sub oc}) with the [theoretical] limiting values. Tandem and multijunction cells are introduced; the {mu}c-Si: H/a-Si: H or [micromorph] tandem solar cell concept is explained in detail, and recent results obtained here are listed and commented. Factors governing the mass-production of thin-film silicon modules are determined both by inherent technical reasons, described in detail, and by economic considerations. The cumulative effect of these factors results in distinct efficiency reductions from values of record laboratory cells to statistical averages of production modules. Finally, applications of thin-film silicon PV modules, especially in building-integrated PV (BIPV) are shown. In this context, the energy yields of thin-film silicon modules emerge as a valuable gauge for module performance, and compare very favourably with those of

  8. Materials That Enhance Efficiency and Radiation Resistance of Solar Cells

    Science.gov (United States)

    Sun, Xiadong; Wang, Haorong

    2012-01-01

    A thin layer (approximately 10 microns) of a novel "transparent" fluorescent material is applied to existing solar cells or modules to effectively block and convert UV light, or other lower solar response waveband of solar radiation, to visible or IR light that can be more efficiently used by solar cells for additional photocurrent. Meanwhile, the layer of fluorescent coating material remains fully "transparent" to the visible and IR waveband of solar radiation, resulting in a net gain of solar cell efficiency. This innovation alters the effective solar spectral power distribution to which an existing cell gets exposed, and matches the maximum photovoltaic (PV) response of existing cells. By shifting a low PV response waveband (e.g., UV) of solar radiation to a high PV response waveband (e.g. Vis-Near IR) with novel fluorescent materials that are transparent to other solar-cell sensitive wavebands, electrical output from solar cells will be enhanced. This approach enhances the efficiency of solar cells by converting UV and high-energy particles in space that would otherwise be wasted to visible/IR light. This innovation is a generic technique that can be readily implemented to significantly increase efficiencies of both space and terrestrial solar cells, without incurring much cost, thus bringing a broad base of economical, social, and environmental benefits. The key to this approach is that the "fluorescent" material must be very efficient, and cannot block or attenuate the "desirable" and unconverted" waveband of solar radiation (e.g. Vis-NIR) from reaching the cells. Some nano-phosphors and novel organometallic complex materials have been identified that enhance the energy efficiency on some state-of-the-art commercial silicon and thin-film-based solar cells by over 6%.

  9. Silicon nanostructures for solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Gourbilleau, F. [CIMAP, UMR CNRS/CEA/Ensicaen 6252, 6 Bd Marechal Juin, 14050 Caen Cedex (France)], E-mail: fabrice.gourbilleau@ensicaen.fr; Dufour, C. [CIMAP, UMR CNRS/CEA/Ensicaen 6252, 6 Bd Marechal Juin, 14050 Caen Cedex (France); Rezgui, B.; Bremond, G. [INL, UMR CNRS 5270, Universite de Lyon, INSA-Lyon, Bat. Blaise Pascal, 7 Av. Jean Capelle, 69621 Villeurbanne Cedex (France)

    2009-03-15

    Among the numerous applications of Si nanostructures in the microelectronic or photonic domains, one which could be promising concerns the use of such structures as the active layer in pin solar cells. By taking advantage of the quantum confinement of the carriers in Si nanograins whose size is lower than 8 nm, it is expected to improve the solar cell efficiency by increasing the absorption range of the solar spectrum. In this work, we report the fabrication, microstructural and optical properties of Si-rich silicon oxide (SRSO) composite layers and SRSO/SiO{sub 2} multilayers fabricated by reactive magnetron sputtering process. This process allows monitoring either the Si nanograins size and/or the Si nanograin density through specific deposition parameters such as the hydrogen rate in the plasma, the substrate temperature, the annealing treatment. Their effects on the photoluminescent properties as well as on the absorption coefficient are discussed. The SRSO/SiO{sub 2} multilayers absorption is higher with respect to the SRSO composite layer. Such behaviour has been attributed to a better control of the Si nanograin size.

  10. Luminescent solar concentrators and all-inorganic nanoparticle solar cells for solar energy harvesting

    Science.gov (United States)

    Sholin, Veronica

    Increasing energy demand and the parallel increase of greenhouse gas emissions are challenging researchers to find new and cleaner energy sources. Solar energy harvesting is arguably the most promising candidate for replacing fossil-fuel power generation. Photovoltaics are the most direct way of collecting solar energy; cost continues to hinder large-scale implementation of photovoltaics, however. Therefore, alternative technologies that will allow the extraction of solar power, while maintaining the overall costs of fabrication, installation, collection, and distribution low, must be explored. This thesis focuses on the fabrication and testing of two types of devices that step up to this challenge: the luminescent solar concentrator (LSC) and all-inorganic nanoparticle solar cells. In these devices I make use of novel materials, semiconducting polymers and inorganic nanoparticles, both of which have lower costs than the crystalline materials used in the fabrication of traditional photovoltaics. Furthermore, the cost of manufacturing LSCs and the nanoparticle solar cells is lower than the manufacturing cost of traditional optics-based concentrators and crystalline solar cells. An LSC is essentially a slab of luminescent material that acts as a planar light pipe. The LSC absorbs incoming photons and channels fluoresced photons toward appropriately located solar cells, which perform the photovoltaic conversion. By covering large areas with relatively inexpensive fluorescing organic dyes or semiconducting polymers, the area of solar cell needed is greatly reduced. Because semiconducting polymers and quantum dots may have small absorption/emission band overlaps, tunable absorption, and longer lifetimes, they are good candidates for LSC fabrication, promising improvement with respect to laser dyes traditionally used to fabricate LSCs. Here the efficiency of LSCs consisting of liquid solutions of semiconducting polymers encased in glass was measured and compared to the

  11. Quantum Dots Investigated for Solar Cells

    Science.gov (United States)

    Bailey, Sheila G.; Castro, Stephanie L.; Raffaelle, Ryne P.; Hepp, Aloysius F.

    2001-01-01

    The NASA Glenn Research Center has been investigating the synthesis of quantum dots of CdSe and CuInS2 for use in intermediate-bandgap solar cells. Using quantum dots in a solar cell to create an intermediate band will allow the harvesting of a much larger portion of the available solar spectrum. Theoretical studies predict a potential efficiency of 63.2 percent, which is approximately a factor of 2 better than any state-of-the-art devices available today. This technology is also applicable to thin-film devices--where it offers a potential four-fold increase in power-to-weight ratio over the state of the art. Intermediate-bandgap solar cells require that quantum dots be sandwiched in an intrinsic region between the photovoltaic solar cell's ordinary p- and n-type regions (see the preceding figure). The quantum dots form the intermediate band of discrete states that allow sub-bandgap energies to be absorbed. However, when the current is extracted, it is limited by the bandgap, not the individual photon energies. The energy states of the quantum dot can be controlled by controlling the size of the dot. Ironically, the ground-state energy levels are inversely proportional to the size of the quantum dots. We have prepared a variety of quantum dots using the typical organometallic synthesis routes pioneered by Ba Wendi et al., in the early 1990's. The most studied quantum dots prepared by this method have been of CdSe. To produce these dots, researchers inject a syringe of the desired organometallic precursors into heated triocytlphosphine oxide (TOPO) that has been vigorously stirred under an inert atmosphere (see the following figure). The solution immediately begins to change from colorless to yellow, then orange and red/brown, as the quantum dots increase in size. When the desired size is reached, the heat is removed from the flask. Quantum dots of different sizes can be identified by placing them under a "black light" and observing the various color differences in

  12. TRANSPARENT COATINGS FOR SOLAR CELLS RESEARCH

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-04-16

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

  13. Enhancing Solar Cell Efficiency Using Photon Upconversion Materials

    Directory of Open Access Journals (Sweden)

    Yunfei Shang

    2015-10-01

    Full Text Available Photovoltaic cells are able to convert sunlight into electricity, providing enough of the most abundant and cleanest energy to cover our energy needs. However, the efficiency of current photovoltaics is significantly impeded by the transmission loss of sub-band-gap photons. Photon upconversion is a promising route to circumvent this problem by converting these transmitted sub-band-gap photons into above-band-gap light, where solar cells typically have high quantum efficiency. Here, we summarize recent progress on varying types of efficient upconversion materials as well as their outstanding uses in a series of solar cells, including silicon solar cells (crystalline and amorphous, gallium arsenide (GaAs solar cells, dye-sensitized solar cells, and other types of solar cells. The challenge and prospect of upconversion materials for photovoltaic applications are also discussed

  14. OPTEC: A Cubesat for Solar Cell Calibration

    Science.gov (United States)

    Landis, Geoffrey; Hepp, Aloysius; Arutyunov, Dennis; White, Kelsey; Witsberger, Paul

    2014-01-01

    A new type of small spacecraft, the cubesat, has introduced a new concept for extremely small, low-cost missions into space. Cubesats are designed to be launched as secondary payloads on other missions, and are made up of unit elements (U) of size 10 cm by 10 cm by 10 cm, with a nominal mass of no more than 1.33 kg per U. We have designed a cubesat, OPTEC (Orbital Photovoltaic Testbed Cubesat) as a low-cost testbed to demonstrate, calibrate, and test solar cell technologies in space. Size of the cubesat is 2U (10x10x20cm, and the mass 2.66 kg. The cubesat deploys from the International Space Station into Low Earth Orbit at an altitude of about 420 km. Up to two 4x8cm test solar panels can be flown, with full I-V curves and temperature measurements taken.

  15. Thin-film cadmium telluride solar cells

    Science.gov (United States)

    Chu, T. L.

    1986-08-01

    The major objective of this work was to demonstrate CdTe devices grown by chemical vapor deposition (CVD) with a total area greater than 1 cm2 and photovoltic efficiencies of at least 13%. During the period covered, various processing steps were investigated for the preparation of thin-film CdTe heterojunction solar cells of the inverted configuration. Glass coated with fluorine-doped tin oxide was used as the substrate. Thin-film heterojunction solar cells were prepared by depositing p-CdTe films on substrates using CVD and close-spaced sublimation (CSS). Cells prepared from CSS CdTe usually have a higher conversion efficiency than those prepared from CVD CdTe, presumably due to the chemical interaction between CdS and CdTe at the interface during the CVD process. The best cell, about 1.2 sq cm in area, had an AM 1.5 (global) efficiency of 10.5%, and further improvements are expected by optimizing the process parameters.

  16. Correcting For Capacitance In Tests Of Solar Cells

    Science.gov (United States)

    Mueller, Robert L.

    1995-01-01

    Modified procedure for testing solar photovoltaic cells and modified software for processing test data provide corrections for effects of cell capacitance. Procedure and software needed because (a) some photovoltaic devices (for example, silicon solar cells with back-surface field region) store minority charge carriers in cell junction and thus exhibit significant capacitance, (b) capacitance affects current-vs.-voltage (I-V) measurements made when transient load connected to cell, and (c) transient load used in unmodified version of test procedure. Corrected I-V curve obtained in test of solar cell according to modified procedure approximates true cell voltage vs. cell current more closely.

  17. Applications of Laser Precisely Processing Technology in Solar Cells

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    According to the design method of laser resonator cavity, we optimized the primary parameters of resonator and utilized LD arrays symmetrically pumping manner to implementing output of the high-brightness laser in our laser cutter, then which was applied to precisely cutting the conductive film of CuInSe2 solar cells, the buried contact silicon solar cells' electrode groove, and perforating in wafer which is used to the emitter wrap through silicon solar cells. Laser processing precision was less than 40μm, the results have met solar cell's fabrication technology, and made finally the buried cells' conversion efficiency be improved from 18% to 21% .

  18. An interim report on the NTS-2 solar cell experiment

    Science.gov (United States)

    Statler, R. L.; Walker, D. H.

    1979-01-01

    Data obtained from the fourteen solar cell modules on the NTS-2 satellite are presented together with a record of panel temperature and sun inclination. The following flight data are discussed: (1) state of the art solar cell configurations which embody improvements in solar cell efficiency through new silicon surface and bulk technology, (2) improved coverslip materials and coverslip bonding techniques, (3) short and long term effects of ultraviolet rejection filters vs. no filters on the cells, (4) degradation on a developmental type of liquid epitaxy gallium-aluminum-arsenide solar cell, and (5) space radiation effects.

  19. Simulation of the Mars Surface Solar Spectra for Optimized Performance of Triple-Junction Solar Cells

    Science.gov (United States)

    Edmondson, Kenneth M.; Joslin, David E.; Fetzer, Chris M.; King, RIchard R.; Karam, Nasser H.; Mardesich, Nick; Stella, Paul M.; Rapp, Donald; Mueller, Robert

    2007-01-01

    The unparalleled success of the Mars Exploration Rovers (MER) powered by GaInP/GaAs/Ge triple-junction solar cells has demonstrated a lifetime for the rovers that exceeded the baseline mission duration by more than a factor of five. This provides confidence in future longer-term solar powered missions on the surface of Mars. However, the solar cells used on the rovers are not optimized for the Mars surface solar spectrum, which is attenuated at shorter wavelengths due to scattering by the dusty atmosphere. The difference between the Mars surface spectrum and the AM0 spectrum increases with solar zenith angle and optical depth. The recent results of a program between JPL and Spectrolab to optimize GaInP/GaAs/Ge solar cells for Mars are presented. Initial characterization focuses on the solar spectrum at 60-degrees zenith angle at an optical depth of 0.5. The 60-degree spectrum is reduced to 1/6 of the AM0 intensity and is further reduced in the blue portion of the spectrum. JPL has modeled the Mars surface solar spectra, modified an X-25 solar simulator, and completed testing of Mars-optimized solar cells previously developed by Spectrolab with the modified X-25 solar simulator. Spectrolab has focused on the optimization of the higher efficiency Ultra Triple-Junction (UTJ) solar cell for Mars. The attenuated blue portion of the spectrum requires the modification of the top sub-cell in the GaInP/GaAs/Ge solar cell for improved current balancing in the triple-junction cell. Initial characterization confirms the predicted increase in power and current matched operation for the Mars surface 60-degree zenith angle solar spectrum.

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

    International Nuclear Information System (INIS)

    We have applied an optical splitting system in order to achieve very high conversion efficiency for a full spectrum multi-junction solar cell. This system consists of multiple solar cells with different band gap optically coupled via an “optical splitter.” An optical splitter is a multi-layered beam splitter with very high reflection in the shorter-wave-length range and very high transmission in the longer-wave-length range. By splitting the incident solar spectrum and distributing it to each solar cell, the solar energy can be managed more efficiently. We have fabricated optical splitters and used them with a wide-gap amorphous silicon (a-Si) solar cell or a CH3NH3PbI3 perovskite solar cell as top cells, combined with mono-crystalline silicon heterojunction (HJ) solar cells as bottom cells. We have achieved with a 550 nm cutoff splitter an active area conversion efficiency of over 25% using a-Si and HJ solar cells and 28% using perovskite and HJ solar cells

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

    Energy Technology Data Exchange (ETDEWEB)

    Uzu, Hisashi, E-mail: Hisashi.Uzu@kaneka.co.jp, E-mail: npark@skku.edu; Ichikawa, Mitsuru; Hino, Masashi; Nakano, Kunihiro; Meguro, Tomomi; Yamamoto, Kenji [Kaneka Corporation, 5-1-1, Torikai-Nishi, Settsu, Osaka 566-0072 (Japan); Hernández, José Luis [Kaneka Belgium N.V., Nijverheidsstraat 16, 2260 Westerlo-Oevel (Belgium); Kim, Hui-Seon; Park, Nam-Gyu, E-mail: Hisashi.Uzu@kaneka.co.jp, E-mail: npark@skku.edu [School of Chemical Engineering and Department of Energy Science, Sungkyunkwan University, 300 Cheoncheon-dong, Jangan-gu, Suwon 440-746 (Korea, Republic of)

    2015-01-05

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

  2. Industrialization of polymer solar cells - phase 1

    Energy Technology Data Exchange (ETDEWEB)

    Lauritzen, H.; Krebs, F.C. [Technical Univ. of Denmark. DTU Energy Conversion, DTU Risoe Campus, Roskilde (Denmark); Andersen, Rasmus B. [Mekoprint A/S, Stoevrimg (Denmark); Bork, J.; Bentzen, B.

    2012-03-15

    A three-phased project with the objective to industrialize DTU's basic polymer solar cell technology was started in the summer of 2009. The technology comprises a specific design of the polymer solar cell and a corresponding roll-to-roll manufacturing process. This basic technology is referred to as ProcessOne in the open literature. The present report relates to the project's phase 1.The key tasks in phase 1 are to stream-line DTU's tech-nology for the industrial utilization, to demonstrate production according to this stream-lined technology at Mekoprint A/S and finally to fertilize the market for polymer solar cells by demonstrating their use in appli-cations that harmonize with their present maturity level. The main focus in the stream-lining of DTU's technology has been to demonstrate a convincing rate of reduction for the production cost, and thereby make a competitive price plausible. This has been materialized as a learning curve showing that the polymer technology presently develops considerably faster than the silicon technology. The polymer solar cells will, under the assumption that both technologies follow a projection of the learning curve, gain a cost-leading position within a reasonable time. A production cost of 5 Euro/Wp has already been demonstrated in DTU's pilot plant, and a road map for the further decrease to 1 Euro/Wp is drawn. This target is expected to be reached in 2013 in the ongoing phase 2 of the project. Another activity essential for the industrialization has been the launch of specialized materials, equipment and services required for the processing of DTU's polymer solar cells. Relevant products and services are made available for sale on DTU's homepage, www.energyconversion.dtu.dk. A production line for polymer solar cells has been established at Mekoprint. For this a retrofit solution was chosen where the core of an existing screen-printing line was dismantled and fitted to a slot-die printing head manufactured in DTU's workshop

  3. Industrialization of polymer solar cells - phase 1

    Energy Technology Data Exchange (ETDEWEB)

    Lauritzen, H.; Krebs, F.C. [Technical Univ. of Denmark. DTU Energy Conversion, DTU Risoe Campus, Roskilde (Denmark); Andersen, Rasmus B. [Mekoprint A/S, Stoevrimg (Denmark); Bork, J.; Bentzen, B.

    2012-03-15

    A three-phased project with the objective to industrialize DTU's basic polymer solar cell technology was started in the summer of 2009. The technology comprises a specific design of the polymer solar cell and a corresponding roll-to-roll manufacturing process. This basic technology is referred to as ProcessOne in the open literature. The present report relates to the project's phase 1.The key tasks in phase 1 are to stream-line DTU's tech-nology for the industrial utilization, to demonstrate production according to this stream-lined technology at Mekoprint A/S and finally to fertilize the market for polymer solar cells by demonstrating their use in appli-cations that harmonize with their present maturity level. The main focus in the stream-lining of DTU's technology has been to demonstrate a convincing rate of reduction for the production cost, and thereby make a competitive price plausible. This has been materialized as a learning curve showing that the polymer technology presently develops considerably faster than the silicon technology. The polymer solar cells will, under the assumption that both technologies follow a projection of the learning curve, gain a cost-leading position within a reasonable time. A production cost of 5 Euro/Wp has already been demonstrated in DTU's pilot plant, and a road map for the further decrease to 1 Euro/Wp is drawn. This target is expected to be reached in 2013 in the ongoing phase 2 of the project. Another activity essential for the industrialization has been the launch of specialized materials, equipment and services required for the processing of DTU's polymer solar cells. Relevant products and services are made available for sale on DTU's homepage, www.energyconversion.dtu.dk. A production line for polymer solar cells has been established at Mekoprint. For this a retrofit solution was chosen where the core of an existing screen-printing line was dismantled and fitted to a slot-die printing head manufactured in DTU's workshop

  4. Intensity modulated short circuit current spectroscopy for solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Kavasoglu, Nese; Sertap Kavasoglu, A.; Birgi, Ozcan; Oktik, Sener [Mugla University, Faculty of Arts and Sciences, Physics Department, TR-48000 Mugla (Turkey); Mugla University Clean Energy Research and Development Centre, TR-48000 Mugla (Turkey)

    2011-02-15

    Understanding charge separation and transport is momentously important for the rectification of solar cell performance. To probe photo-generated carrier dynamics, we implemented intensity modulated short circuit current spectroscopy (IMSCCS) on porous Si and Cu(In{sub x},Ga{sub 1-x})Se{sub 2} solar cells. In this experiment, the solar cells were lightened with sinusoidally modulated monochromatic light. The photocurrent response of the solar cell as a function of modulation frequency is measured as the optoelectronic transfer function of the system. The optoelectronic transfer function introduces the connection between the modulated light intensity and measured AC current of the solar cell. In this study, interaction of free carriers with the density of states of the porous Si and Cu(In{sub x}, Ga{sub 1-x})Se{sub 2} solar cells was studied on the basis of charge transport time by IMSCCS data. (author)

  5. Engineering Schottky contacts in open-air fabricated heterojunction solar cells to enable high performance and ohmic charge transport.

    Science.gov (United States)

    Hoye, Robert L Z; Heffernan, Shane; Ievskaya, Yulia; Sadhanala, Aditya; Flewitt, Andrew; Friend, Richard H; MacManus-Driscoll, Judith L; Musselman, Kevin P

    2014-12-24

    The efficiencies of open-air processed Cu2O/Zn(1-x)Mg(x)O heterojunction solar cells are doubled by reducing the effect of the Schottky barrier between Zn(1-x)Mg(x)O and the indium tin oxide (ITO) top contact. By depositing Zn(1-x)Mg(x)O with a long band-tail, charge flows through the Zn(1-x)Mg(x)O/ITO Schottky barrier without rectification by hopping between the sub-bandgap states. High current densities are obtained by controlling the Zn(1-x)Mg(x)O thickness to ensure that the Schottky barrier is spatially removed from the p-n junction, allowing the full built-in potential to form, in addition to taking advantage of the increased electrical conductivity of the Zn(1-x)Mg(x)O films with increasing thickness. This work therefore shows that the Zn(1-x)Mg(x)O window layer sub-bandgap state density and thickness are critical parameters that can be engineered to minimize the effect of Schottky barriers on device performance. More generally, these findings show how to improve the performance of other photovoltaic system reliant on transparent top contacts, e.g., CZTS and CIGS. PMID:25418326

  6. Characteristics of Bilayer Molybdenum Films Deposited Using RF Sputtering for Back Contact of Thin Film Solar Cells

    Directory of Open Access Journals (Sweden)

    Sea-Fue Wang

    2014-01-01

    Full Text Available Mo films prepared under a single deposition condition seldom simultaneously obtain a low resistivity and a good adhesion necessary for use in solar cells. In order to surmount the obstacle, bilayer Mo films using DC sputtering at a higher working pressure and a lower working pressure have been attempted as reported in the literature. In this study, RF sputtering with different powers in conjunction with different working pressures was explored to prepare bilayer Mo film. The first bottom layer was grown at a RF sputtering power of 30 W and a working pressure of 12 mTorr, and the second top layer was deposited at 100 W and 4.5 mTorr. The films revealed a columnar growth with a preferred orientation along the (110 plane. The bilayer Mo films reported an electrical resistivity of 6.35 × 10−5 Ω-cm and passed the Scotch tape test for adhesion to the soda-lime glass substrate, thereby qualifying the bilayer Mo films for use as back metal contacts for CIGS substrates.

  7. Solar Cell Nanotechnology Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Das, Biswajit [Univ. of Nevada, Las Vegas, NV (United States)

    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

  8. Progress in batteries and solar cells. Volume 5

    International Nuclear Information System (INIS)

    The 89 articles in this book are on research in batteries, solar cells and fuel cells. Topics include uses of batteries in electric powered vehicles, load management in power plants, batteries for miniature electronic devices, electrochemical processes, and various electrode and electrolyte materials, including organic compounds. Types of batteries discussed are lithium, lead-acid, manganese dioxide, Silver cells, Air cells, Nickel cells and solar cells. Problems of recharging and life cycle are also discussed

  9. Vaping cannabis (marijuana): parallel concerns to e-cigs?

    Science.gov (United States)

    Budney, Alan J; Sargent, James D; Lee, Dustin C

    2015-11-01

    The proliferation of vaporization ('vaping') as a method for administering cannabis raises many of the same public health issues being debated and investigated in relation to e-cigarettes (e-cigs). Good epidemiological data on the prevalence of vaping cannabis are not yet available, but with current trends towards societal approval of medicinal and recreational use of cannabis, the pros and cons of vaping cannabis warrant study. As with e-cigs, vaping cannabis portends putative health benefits by reducing harm from ingesting toxic smoke. Indeed, vaping is perceived and being sold as a safer way to use cannabis, despite the lack of data on the health effects of chronic vaping. Other perceived benefits include better taste, more efficient and intense effects and greater discretion which allows for use in more places. Unfortunately, these aspects of vaping could prompt an increased likelihood of trying cannabis, earlier age of onset, more positive initial experiences, and more frequent use, thereby increasing the probability of problematic use or addiction. Sales and marketing of vaping devices with no regulatory guidelines, especially related to advertising or product development targeting youth, parallels concerns under debate related to e-cigs and youth. Thus, the quandary of whether or not to promote vaping as a safer method of cannabis administration for those wishing to use cannabis, and how to regulate vaping and vaping devices, necessitates substantial investigation and discussion. Addressing these issues in concert with efforts directed towards e-cigs may save time and energy and result in a more comprehensive and effective public health policy on vaping.

  10. Vaping cannabis (marijuana): parallel concerns to e-cigs?

    Science.gov (United States)

    Budney, Alan J; Sargent, James D; Lee, Dustin C

    2015-11-01

    The proliferation of vaporization ('vaping') as a method for administering cannabis raises many of the same public health issues being debated and investigated in relation to e-cigarettes (e-cigs). Good epidemiological data on the prevalence of vaping cannabis are not yet available, but with current trends towards societal approval of medicinal and recreational use of cannabis, the pros and cons of vaping cannabis warrant study. As with e-cigs, vaping cannabis portends putative health benefits by reducing harm from ingesting toxic smoke. Indeed, vaping is perceived and being sold as a safer way to use cannabis, despite the lack of data on the health effects of chronic vaping. Other perceived benefits include better taste, more efficient and intense effects and greater discretion which allows for use in more places. Unfortunately, these aspects of vaping could prompt an increased likelihood of trying cannabis, earlier age of onset, more positive initial experiences, and more frequent use, thereby increasing the probability of problematic use or addiction. Sales and marketing of vaping devices with no regulatory guidelines, especially related to advertising or product development targeting youth, parallels concerns under debate related to e-cigs and youth. Thus, the quandary of whether or not to promote vaping as a safer method of cannabis administration for those wishing to use cannabis, and how to regulate vaping and vaping devices, necessitates substantial investigation and discussion. Addressing these issues in concert with efforts directed towards e-cigs may save time and energy and result in a more comprehensive and effective public health policy on vaping. PMID:26264448

  11. GaP/Si heterojunction Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-05-11

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

  12. Energy yield determination of concentrator solar cells using laboratory measurements

    OpenAIRE

    Geisz, John F.; García Vara, Iván; Mcmahon, William E.; Steiner, Myles A.; Ochoa Gómez, Mario; France, Ryan M.; Habte, Aron; Friedman, Daniel J.

    2015-01-01

    The annual energy conversion efficiency is calculated for a four junction inverted metamorphic solar cell that has been completely characterized in the laboratory at room temperature using measurements fit to a comprehensive optoelectronic model of the multijunction solar cells. A simple model of the temperature dependence is used redict the performance of the solar cell under varying temperature and spectra characteristic of Golden, CO for an entire year. The annual energy conversion efficie...

  13. Highly efficient light management for perovskite solar cells

    OpenAIRE

    Dong-Lin Wang; Hui-Juan Cui; Guo-Jiao Hou; Zhen-Gang Zhu; Qing-Bo Yan; Gang Su

    2016-01-01

    Organic-inorganic halide perovskite solar cells have enormous potential to impact the existing photovoltaic industry. As realizing a higher conversion efficiency of the solar cell is still the most crucial task, a great number of schemes were proposed to minimize the carrier loss by optimizing the electrical properties of the perovskite solar cells. Here, we focus on another significant aspect that is to minimize the light loss by optimizing the light management to gain a high efficiency for ...

  14. Monocrystalline silicon solar cells applied in photovoltaic system

    OpenAIRE

    L.A. Dobrzański; A. Drygała; M. Giedroć; Macek, M

    2012-01-01

    Purpose: The aim of the paper is to fabricate the monocrystalline silicon solar cells using the conventional technology by means of screen printing process and to make of them photovoltaic system.Design/methodology/approach: The investigation of current – voltage characteristic to determinate basic electrical properties of monocrystalline silicon solar cells were investigated under Standard Test Condition. Photovoltaic module was produced from solar cells with the largest short-circuit curren...

  15. Applicability of the Meyer-Neldel rule to solar cells

    Science.gov (United States)

    Goradia, C.; Weizer, V. G.

    1984-01-01

    A comparison of data taken on high quality silicon, GaAs, and GaInAs solar cells with those taken on a variety of homojunction, heterojunction, and metal-insulator-semiconductor devices indicates that while the Meyer-Neldel rule may be applicable to certain types of solar cells it is not applicable to well-behaved, diffusion-controlled homojunction devices. It cannot be used, therefore, as a universal rule to predict maximum achievable solar cell voltages.

  16. A numerical semiconductor model applicable to organic solar cells

    OpenAIRE

    Minnaert, Ben; Burgelman, Marc; Heereman, Frédéric

    2007-01-01

    Excitons are marginally important in classical semiconductor device physics, and their treatment is not included in standard solar cell modelling. However, in organic semiconductors and solar cells, the role of excitons is essential, as the primary effect of light absorption is exciton generation, and free electrons and holes are created by exciton dissociation. First steps to include excitons in solar cell modelling were presented by Green and Zhang. We extended their model (2006), includin...

  17. Performance improvement of silicon solar cells by nanoporous silicon coating

    Directory of Open Access Journals (Sweden)

    Dzhafarov T. D.

    2012-04-01

    Full Text Available In the present paper the method is shown to improve the photovoltaic parameters of screen-printed silicon solar cells by nanoporous silicon film formation on the frontal surface of the cell using the electrochemical etching. The possible mechanisms responsible for observed improvement of silicon solar cell performance are discussed.

  18. Simulation of Organic Solar Cells Using AMPS-1D Program

    Directory of Open Access Journals (Sweden)

    Samah G. Babiker

    2012-03-01

    Full Text Available The analysis of microelectronic and photonic structure in one dimension program [AMPS-1D] program has been successfully used to study inorganic solar cells. In this work the program has been used to optimize the performance of the organic solar cells. The cells considered consist of poly(2-methoxy-5-(3,7- dimethyloctyloxy-1,4-phenylenevinylene [MDMO-PPV

  19. Plastic solar cell interface and morphological characterization

    Science.gov (United States)

    Guralnick, Brett W.

    Plastic solar cell research has become an intense field of study considering these devices may be lightweight, flexible and reduce the cost of photovoltaic devices. The active layer of plastic solar cells are a combination of two organic components which blend to form an internal morphology. Due to the poor electrical transport properties of the organic components it is important to understand how the morphology forms in order to engineer these materials for increased efficiency. The focus of this thesis is a detailed study of the interfaces between the plastic solar cell layers and the morphology of the active layer. The system studied in detail is a blend of P3HT and PCBM that acts as the primary absorber, which is the electron donor, and the electron acceptor, respectively. The key morphological findings are, while thermal annealing increases the crystallinity parallel to the substrate, the morphology is largely unchanged following annealing. The deposition and mixing conditions of the bulk heterojunction from solution control the starting morphology. The spin coating speed, concentration, solvent type, and solution mixing time are all critical variables in the formation of the bulk heterojunction. In addition, including the terminals or inorganic layers in the analysis is critical because the inorganic surface properties influence the morphology. Charge transfer in the device occurs at the material interfaces, and a highly resistive transparent conducting oxide layer limits device performance. It was discovered that the electron blocking layer between the transparent conducting oxide and the bulk heterojunction is compromised following annealing. The electron acceptor material can diffuse into this layer, a location which does not benefit device performance. Additionally, the back contact deposition is important since the organic material can be damaged by the thermal evaporation of Aluminum, typically used for plastic solar cells. Depositing a thin thermal and

  20. Various configurations for continuous silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Sameh, M.

    1977-10-01

    For the same exposed silicon area, solar cells may be produced in a more convenient and mechanically rugged structure than narrow thin ribbons or sheets. Compactness ratio is calculated for each of several suggested geometries. For an Archimedes and square spirals, compactness ratio increases with increasing number of turns and closer tolerance. For a serpent, compactness ratio increases with decreasing number of turns, closer tolerance and increasing ratio of ribbon width to side length. For a zigzag compactness ratio is minimum for an apex angle 45/sup 0/ and smaller ratio of ribbon width to side length.

  1. Transmutation doping of silicon solar cells

    Science.gov (United States)

    Wood, R. F.; Westbrook, R. D.; Young, R. T.; Cleland, J. W.

    1977-01-01

    Normal isotopic silicon contains 3.05% of Si-30 which transmutes to P-31 after thermal neutron absorption, with a half-life of 2.6 hours. This reaction is used to introduce extremely uniform concentrations of phosphorus into silicon, thus eliminating the areal and spatial inhomogeneities characteristic of chemical doping. Annealing of the lattice damage in the irradiated silicon does not alter the uniformity of dopant distribution. Transmutation doping also makes it possible to introduce phosphorus into polycrystalline silicon without segregation of the dopant at the grain boundaries. The use of neutron transmutation doped (NTD) silicon in solar cell research and development is discussed.

  2. Recent progress in micromorph solar cells

    OpenAIRE

    Meier, Johannes; Dubail, S.; Cuperus, J.; Kroll, U.; Platz, R.; Torres, Pedro; Anna Selvan, J. A.; Pernet, P.; Beck, N; Pellaton Vaucher, N.; Hof, Ch.; Fischer, Diego; Keppner, Herbert; Shah, Arvind

    2008-01-01

    Recently, we have demonstrated that intrinsic hydrogenated microcrystalline silicon, as deposited by the very high frequency glow-discharge technique, can be used as the active layers of p–i–n solar cells. Our microcrystalline silicon represents a new form of thin film crystalline silicon that can be deposited (in contrast to any other approach found in literature) at substrate temperatures as low as 200°C. The combination of amorphous and microcrystalline material leads to a ‘real' silicon-b...

  3. Intermediate Bandgap Solar Cells From Nanostructured Silicon

    Energy Technology Data Exchange (ETDEWEB)

    Black, Marcie [Bandgap Engineering, Lincoln, MA (United States)

    2014-10-30

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

  4. An analysis of glass–glass CIGS manufacturing costs

    Energy Technology Data Exchange (ETDEWEB)

    Horowitz, Kelsey A. W.; Fu, Ran; Woodhouse, Michael

    2016-09-01

    This article examines current cost drivers and potential avenues to reduced cost for monolithic, glass-glass Cu(In,Ga)(Se,S)2 (CIGS) modules by constructing a comprehensive bottom-up cost model. For a reference case where sputtering plus batch sulfurization after selenization (SAS) is employed, we compute a manufacturing cost of $69/m2 if the modules are made in the United States at a 1 GW/year production volume. At 14% module efficiency, this corresponds to a manufacturing cost of $0.49/WDC and a minimum sustainable price (MSP) of $0.67/WDC. We estimate that MSP could vary within +/-20% of this value given the range of quoted input prices, and existing variations in module design, manufacturing processes, and manufacturing location. Potential for reduction in manufacturing costs to below $0.40/WDC may be possible if average production module efficiencies can be increased above 17% without increasing $/m2 costs; even lower costs could be achieved if $/m2 costs could be reduced, particularly via innovations in the CIGS deposition process or balance-of-module elements. We present the impact on cost of regional factors, CIGS deposition method, device design, and price fluctuations. One metric of competitiveness-levelized cost of energy (LCOE) -- is also assessed for several U.S. locations and compared to that of standard multi-crystalline silicon (m(c-Si)) and cadmium telluride (CdTe).

  5. Nanostructured InGaP Solar Cells Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The operating conditions of conventional multijunction solar cells are severely limited by the current matching requirements of serially connected devices. The goal...

  6. Flexible solar cells based on curved surface nano-pyramids

    Science.gov (United States)

    Shrestha, Anil; Mizuno, Genki; Oduor, Patrick; Dutta, Achyut K.; Dhar, Nibir K.; Lewis, Jay

    2016-05-01

    The advent of ultrathin crystalline silicon (c-Si) solar cells has significantly reduced the cost of silicon solar cells by consuming less material. However, the very small thickness of ultrathin solar cells poses a challenge to the absorption of sufficient light to provide efficiency that is competitive to commercial solar cells. Light trapping mechanisms utilizing nanostructure technologies have been utilized to alleviate this problem. Unfortunately, a significant portion of light is still being lost even before entering the solar cells because of reflection. Different kinds of nanostructures have been employed to reduce reflection from solar cells, but reflection losses still prevail. In an effort to reduce reflection loss, we have used an array of modified nanostructures based cones or pyramids with curved sides, which matches the refractive index of air to that of silicon. Moreover, use of these modified nano-pyramids provides a quintic (fifth power) gradient index layer between air and silicon, which significantly reduces reflection. The solar cells made of such nanostructures not only significantly increase conversion efficiency at reduced usage of crystalline silicon material (e.g. thinner), but it also helps to make the c-Si based solar cell flexible. Design and optimization of flexible c-Si solar cell is presented in the paper.

  7. Flexible PCPDTBT:PCBM solar cells with integrated grating structures

    DEFF Research Database (Denmark)

    Oliveira Hansen, Roana Melina de; Liu, Yinghui; Madsen, Morten;

    2013-01-01

    We report on development of flexible PCPDTBT:PCBM solar cells with integrated diffraction gratings on the bottom electrodes. The presented results address PCPDTBT:PCBM solar cells in an inverted geometry, which contains implemented grating structures whose pitch is tuned to match the absorption...... spectra of the active layer. This optimized solar cell structure leads to an enhanced absorption in the active layer and thus improved short-circuit currents and power conversion efficiencies in the fabricated devices. Fabrication of the solar cells on thin polyimide substrates which are compatible...

  8. E. coli cells adaptation to solar environment

    Energy Technology Data Exchange (ETDEWEB)

    Favre, A. [Institute J. Monod, Paris (France)

    1997-12-31

    Full text. Photo mutagenesis of E.coli cells exposed to solar light results essentially from the combined effect of its U V C, U V B and U V A components. The high photo mutagenic efficiency of UVC is known to be hampered when the cells have been pre illuminated with near UV light. Near UV light triggers the growth delay effect at sublethal fluences ( and reveals poorly mutagenic). The chromophore leading to this growth lag effect is a rare nucleoside, 4-thio uridine s4U, present only in position 8 of E. coli tRNAs. Upon photo activation s4U led to formation of an intramolecular 8-13 crosslink in a number of tRNA species, including tRNAphe and tRNApro. These two crosslinked Trna species can no more be efficiently acylated by their corresponding tRNa ligases and accumulate on the uncharged from thus preventing protein synthesis, and effect amplified by the so called stringent response. Accordingly nuvA mutant cells no more exhibit growth delay UVC induced mutagenesis involves activation of the inducible error-prone SOS system which requires protein synthesis. By compacting the level of expression of the SOS gene sfiA (using a sfiA:lacZ fusion) in wild-type and nuvA mutant cells submitted to combined UVC, UVA radiations, we have demonstrated that indeed 4-thio uridine behaves as an anti photo mutagenic device. Adaptation of E. coli cell to its solar environment will be discussed in the light of this finding

  9. Photosensitizers from Spirulina for Solar Cell

    Directory of Open Access Journals (Sweden)

    Liqiu Wang

    2014-01-01

    Full Text Available Spirulina is a kind of blue-green algae with good photosynthetic efficiency and might be used for photovoltaic power generation. So this paper used living spirulina as novel photosensitizer to construct spirulina biosolar cell. The results showed that spirulina had the photoelectric conversion effect, and could let the spirulina biosolar cell have 70 μA photocurrent. Meanwhile, adding glucose sucrose or chitosan in the spirulina anode chamber, they could make the maxima current density of the cell greatly increased by 80 μA, 100 μA, and 84 μA, respectively, and the sucrose could improve the maximum power density of the cell to 63 mW/m−2. Phycobiliprotein played an important role in the photosynthesis of spirulina. So in this paper phycobiliprotein was extracted from spirulina to composite with squaraine dye to sensitize nanocrystalline TiO2 photoanode for building dye sensitized solar cell, and the photoelectric properties of the cell also were investigated.

  10. Recent progress in micromorph solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Meier, J.; Dubail, S.; Cuperus, J.; Kroll, U.; Platz, R.; Torres, P.; Anna Selvan, J.A.; Pernet, P.; Beck, N.; Pellaton Vaucher, N.; Hof, Ch.; Fischer, D.; Keppner, H.; Shah, A. [Institut de Microtechnique IMT, A.-L. Breguet 2, Universite de Neuchatel, CH-2000 Neuchatel (Switzerland)

    1998-05-11

    Recently, we have demonstrated that intrinsic hydrogenated microcrystalline silicon, as deposited by the very high frequency glow-discharge technique, can be used as the active layers of p-i-n solar cells. Our microcrystalline silicon represents a new form of thin film crystalline silicon that can be deposited (in contrast to any other approach found in literature) at substrate temperatures as low as 200C. The combination of amorphous and microcrystalline material leads to a `real` silicon-based tandem structure, which we label `micromorph` cell. Meanwhile, stabilised efficiencies of 10.7% have been confirmed. In this paper, we present an improved micromorph tandem cell with 12% stabilised efficiency measured under outdoor conditions. Dark conductivity and combined SIMS measurements performed on intrinsic microcrystalline silicon layers reveal a post-oxidation of the film surface. However, a perfect chemical stability of entire microcrystalline cells as well as micromorph cells is presented. Variations of the p/i interface treatment show that an increase of the open circuit voltages from 450 mV up to 568 mV are achievable for microcrystalline cells, but such devices have reduced fill factors

  11. A Solar Cell That Is Triggered by Sun and Rain.

    Science.gov (United States)

    Tang, Qunwei; Wang, Xiaopeng; Yang, Peizhi; He, Benlin

    2016-04-18

    All-weather solar cells are promising in solving the energy crisis. A flexible solar cell is presented that is triggered by combining an electron-enriched graphene electrode with a dye-sensitized solar cell. The new solar cell can be excited by incident light on sunny days and raindrops on rainy days, yielding an optimal solar-to-electric conversion efficiency of 6.53 % under AM 1.5 irradiation and current over microamps as well as a voltage of hundreds of microvolts by simulated raindrops. The formation of π-electron|cation electrical double-layer pseudocapacitors at graphene/raindrop interface is contributable to current and voltage outputs at switchable charging-discharging process. The new concept can guide the design of advanced all-weather solar cells. PMID:26996147

  12. Solar Cell Fabrication Studies Pertinent to Developing Countries.

    Science.gov (United States)

    Prah, Joseph Henry

    That there is a need in the world today, and in the Third World in particular, for developing renewable energy sources is a proposition without question. Toward that end, the harnessing of solar energy has attracted much attention recently. In this thesis, we have addressed the question of Photovoltaics among the many approaches to the problem as being of poignant relevance in the Third World. Based on our studies, which involved the physics of solar cells, various solar cell configurations, the materials for their fabrication and their fabrication sequences, we arrived at the conclusion that silicon homojunction solar cells are best suited to the present needs and environment of, and suitable for development in the Third World, though Cadmium Sulphide-Cuprous Sulphide solar cell could be considered as a viable future candidate. Attendant with the adoption of photovoltaics as electric energy supply, is the problem of technology transfer and development. Towards that goal, we carried out in the laboratory, the fabrication of solar cells using very simple fabrication sequences and materials to demonstrate that tolerable efficiencies are achievable by their use. The view is also presented that for a thriving and viable solar cell industry in the Third World, the sine qua non is an integrated national policies involving all facets of solar cell manufacture and application, namely, material processing and fabrication, basic research, and development and socio -economic acceptance of solar cell appliances. To demonstrate how basic research could benefit solar cell fabrication, we undertook a number of experiments, such as varying our fabrication sequences and materials, finding their radiation tolerance, and carrying out Deep Level Transient Spectroscopy (DLTS) studies, in an attempt to understand some of the fabrication and environmental factors which limit solar cell performance. We thus found that subjecting wafers to preheat treatments does not improve solar cell

  13. Amorphous and microcrystalline silicon applied in very thin tandem solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Schicho, Sandra

    2011-07-28

    Thin-film solar cells are fabricated by low-cost production processes, and are therefore an alternative to conventionally used wafer solar cells based on crystalline silicon. Due to the different band gaps, tandem cells that consist of amorphous (a-Si:H) and microcrystalline ({mu}c-Si:H) single junction solar cells deposited on top of each other use the solar spectrum much more efficient than single junction solar cells. The silicon layers are usually deposited on TCO (Transparent Conductive Oxide)-coated glass and metal- or plastic foils. Compared to the CdTe and CIGS based thin-film technologies, silicon thin-film solar cells have the advantage that no limitation of raw material supply is expected and no toxic elements are used. Nevertheless, the production cost per Wattpeak is the decisive factor concerning competitiveness and can be reduced by, e.g., shorter deposition times or reduced material consumption. Both cost-reducing conceptions are simultaneously achieved by reducing the a-Si:H and {mu}c-Si:H absorber layer thicknesses in a tandem device. In the work on hand, the influence of an absorber layer thickness reduction up to 77% on the photovoltaic parameters of a-Si:H/{mu}c-Si:H tandem solar cells was investigated. An industry-oriented Radio Frequency Plasma-Enhanced Chemical Vapour Deposition (RF-PECVD) system was used to deposit the solar cells on glass substrates coated with randomly structured TCO layers. The thicknesses of top and bottom cell absorber layers were varied by adjusting the deposition time. Reduced layer thicknesses lead to lower absorption and, hence, to reduced short-circuit current densities which, however, are partially balanced by higher open-circuit voltages and fill factors. Furthermore, by using very thin amorphous top cells, the light-induced degradation decreases tremendously. Accordingly, a thickness reduction of 75% led to an efficiency loss of only 21 %. By adjusting the parameters for the deposition of a-Si:H top cells, a

  14. Coupling flexible solar cell with parabolic trough solar-concentrator-prototype design and performance

    Science.gov (United States)

    Panin, Alexander; Bergquist, Jonathon

    2007-10-01

    Solar cells are still too expensive (5-20/watt) to compete with traditional fossil fuel power generating methods (˜1/watt). Parabolic trough solar concentrator has the advantage of modest concentration ratio (10-100) which is well suited for coupling with solar cell. Thus using small area solar cell placed in the focal line of parabolic trough may be economically viable alternative to flat solar panels. We experiment with flexible solar cell (backed by water cooling pipe) placed in the focus of parabolic trough reflector. Another advantage of parabolic trough concentrator is very relaxed tracking requirement. For example, east-west oriented concentrator (aligned with the ecliptic plane) does not even need any tracking during core 4-6 hours around noon (when maximum illumination is available). The design and the performance of the prototype, as well as possible economical benefits of full scale projects are discussed in the presentation.

  15. Space solar cells - High efficiency and radiation damage

    Science.gov (United States)

    Brandhorst, H. W., Jr.; Bernatowicz, D. T.

    1980-01-01

    The proceedings of the Third Solar Cell High Efficiency and Radiation Damage Meeting are outlined. The topics covered included high efficiency silicon solar cells, silicon solar cell radiation damage, GaAs solar cell performance, and 30 percent conversion devices. The study of radiation damage from a fundamental defect-centered basis is discussed and evaluated as a focus of future work. 18% AM0 efficiency and 0.7 V open-circuit voltages are designated as achievable goals for silicon solar cells, and the potential for 30% AM0 efficiencies from monolithic tandem cell designs without sunlight concentration is noted. In addition to its potential for 20% AM0 efficiencies, the GaAs cell offers the possibility of a radiation-insensitive power supply when operated at temperatures near 200 C.

  16. Enhancing Solar Cell Efficiencies through 1-D Nanostructures

    OpenAIRE

    Yu Kehan; Chen Junhong

    2008-01-01

    Abstract The current global energy problem can be attributed to insufficient fossil fuel supplies and excessive greenhouse gas emissions resulting from increasing fossil fuel consumption. The huge demand for clean energy potentially can be met by solar-to-electricity conversions. The large-scale use of solar energy is not occurring due to the high cost and inadequate efficiencies of existing solar cells. Nanostructured materials have offered new opportunities to design more efficient solar ce...

  17. Hybrid Perovskite/Perovskite Heterojunction Solar Cells.

    Science.gov (United States)

    Hu, Yinghong; Schlipf, Johannes; Wussler, Michael; Petrus, Michiel L; Jaegermann, Wolfram; Bein, Thomas; Müller-Buschbaum, Peter; Docampo, Pablo

    2016-06-28

    Recently developed organic-inorganic hybrid perovskite solar cells combine low-cost fabrication and high power conversion efficiency. Advances in perovskite film optimization have led to an outstanding power conversion efficiency of more than 20%. Looking forward, shifting the focus toward new device architectures holds great potential to induce the next leap in device performance. Here, we demonstrate a perovskite/perovskite heterojunction solar cell. We developed a facile solution-based cation infiltration process to deposit layered perovskite (LPK) structures onto methylammonium lead iodide (MAPI) films. Grazing-incidence wide-angle X-ray scattering experiments were performed to gain insights into the crystallite orientation and the formation process of the perovskite bilayer. Our results show that the self-assembly of the LPK layer on top of an intact MAPI layer is accompanied by a reorganization of the perovskite interface. This leads to an enhancement of the open-circuit voltage and power conversion efficiency due to reduced recombination losses, as well as improved moisture stability in the resulting photovoltaic devices. PMID:27228558

  18. Chalcogenide photovoltaic solar cells of special interest

    Energy Technology Data Exchange (ETDEWEB)

    Champness, C.H. (McGill Univ., Montreal, Quebec (Canada))

    1988-08-01

    A brief review is given of those semiconducting selenides and tellurides that appear suitable for the absorber layer of a photovoltaic solar cell, with energy gaps in the range 1 to 2 eV. Furthermore, to obtain a lower cost cell, the semiconductor is also required to be used in the form of a thin polycrystalline film, necessitating a high optical absorption coefficient in the material. At the present time the two best chalcogenides meeting these requirements are the compounds CuInSe{sub 2} and CdTe, both of which have been used in polycrystalline thin film structures with CdS, as the window layer, yielding conversion efficiencies of over 10%. They have also demonstrated very good chemical stability.

  19. Dendritic web silicon for solar cell application

    Science.gov (United States)

    Seidensticker, R. G.

    1977-01-01

    The dendritic web process for growing long thin ribbon crystals of silicon and other semiconductors is described. Growth is initiated from a thin wirelike dendrite seed which is brought into contact with the melt surface. Initially, the seed grows laterally to form a button at the melt surface; when the seed is withdrawn, needlelike dendrites propagate from each end of the button into the melt, and the web portion of the crystal is formed by the solidification of the liquid film supported by the button and the bounding dendrites. Apparatus used for dendritic web growth, material characteristics, and the two distinctly different mechanisms involved in the growth of a single crystal are examined. The performance of solar cells fabricated from dendritic web material is indistinguishable from the performance of cells fabricated from Czochralski grown material.

  20. Room-Temperature Chemical Solution Treatment for Flexible ZnS(O,OH)/Cu(In,Ga)Se2 Solar Cell: Improvements in Interface Properties and Metastability.

    Science.gov (United States)

    Ho, Wei-Hao; Hsu, Chia-Hao; Yeh, Tzu-Hsuan; Chang, Yu-Han; Wei, Shih-Yuan; Lin, Tzu-Ying; Lai, Chih-Huang

    2016-03-01

    We demonstrate an effective room-temperature chemical solution treatment, by using thioacetamide (S treatment) or thioacetamide-InCl3 (In-S treatment) solution, on Cu(In,Ga)Se2 (CIGSe) surface to engineer the ZnS(O,OH)/CIGSe interface and junction quality, leading to enhanced efficiency and minimized metastability of flexible solar cells. The control device without treatment reveals a relatively low efficiency of 8.15%, which is significantly improved to 9.74% by In-S treatment, and 10.39% by S treatment. Results of X-ray photoelectron spectroscopy suggest that S is incorporated into CIGSe surface forming CIGSSe by S treatment, whereas a thin In-S layer is formed on CIGSe surface by In-S treatment with reduced amount of S diffusing into CIGSe. PL spectra and TRPL lifetime further reveal that S incorporation into CIGS surface may substitute the OSe and/or directly occupy the vacant anion site (VSe), resulting in the effective passivation of the recombination centers at CIGSe surface. Moreover, reducing the concentrations of VSe may thereby decrease the density of (VCu-VSe) acceptors, which can minimize the metastability of ZnS(O,OH)/CIGSe solar cells. With S treatment, the light soaking (LS) time of ZnS(O,OH)/CIGSe device is reduced approximately to one-half of control one. Our approach can be potentially applied for alternative Cd-free buffer layers to achieve high efficiency and low metastability. PMID:26905219