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Sample records for cigs based solar

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

    Science.gov (United States)

    Wang, Mingqing; Choy, Kwang-Leong

    2016-07-06

    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.

  3. TEMPERATUREEFFECT OFELECTRICALPROPERTIES OF CIGS SOLAR CELL

    Directory of Open Access Journals (Sweden)

    A. M. Ferouani

    2015-07-01

    Full Text Available In this paper we are interested in studying the copper–indium–gallium–selenium (CIGS solar cells sandwiched between cadmium sulfide (CdS and ZnO as buffer layers, and Molybdenum (Mo. Thus, we report our simulation results using the capacitance simulator (SCAPS in terms of layer thickness, absorber layer band gap and operating temperature to find out the optimum choice. An efficiency of 20.61% (with Voc of 635.2mV, Jsc of 44.08 mA/cm2 and fill factor of 0.73 has been achieved with CdS used as buffer layer as the reference case. It is also found that the high efficiency CIGS cells with the low temperature were a very high efficiency conversion.

  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.; Van Deelen, J.; 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. 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.

  6. Mechanochemically Synthesized CIGS Nanocrystalline Powder for Solar Cell Application

    Directory of Open Access Journals (Sweden)

    Bharati Rehani

    2013-05-01

    Full Text Available Copper Indium Gallium Diselenide (CIGS is a compound semiconductor material from the group of I-III-VI. The material is a solid solution of copper, indium and selenium (CIS and copper, gallium and selenium with an empirical formula of CuIn(1 – xGaxSe2, where 0  x  1. CIGS has an exceptionally high absorption coefficient of more than 105 cm – 1 for 1.5 eV. Solar cells prepared from absorber layers of CIGS materials have shown an efficiency higher than 20 %. CuIn(1 – xGaxSe2 (x  0.3 nanocrystalline compound was mechanochemically synthesized by high-energy milling in a planetary ball mill. The phase identification and crystallite size of milled powders at different time intervals were carried out by X-ray diffraction (XRD. The XRD analysis indicates chalcopyrite structure and the crystallite size of about 10 nm of high-energy milled CIGS powder after two and half hours of milling. An attempt for preparing the thin film from CIGS nanocrystalline powder was carried out using the flash evaporation technique. Scanning electron microscopy (SEM reveals uniform distribution of CIGS particles in thin film.

  7. 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,

  8. 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%.

  9. Thin film CIGS solar cells with a novel low cost process - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Tiwari, A. N.; Romanyuk, Y.

    2010-01-15

    Novel manufacturing routes for efficient and low-cost Cu(In,Ga)Se{sub 2} (called CIGS) thin film solar cells are explored and patented. CIGS has proven its suitability for highly efficient and extremely stable solar cells. The low-cost methods allow impurity free material synthesis, fast large-area deposition, high material utilization and a very short energy payback time with drastically lower manufacturing costs. Two non-vacuum, solution-based approaches are investigated to deposit thin layers of CIGS. The first approach considers incorporation of copper into indium gallium selenide precursor layers by ion-exchange from aqueous or organic solutions. Organic solutions provide faster copper incorporation and do not corrode the metal back contact. Solar cells processed from selenized precursor films exhibit efficiencies of up to 4.1%. The second approach with paste coating of inorganic salt solution results in a solar cell efficiency of 4% (record 6.7%), where further improvements are hindered by the presence of the residual carbon layer. Using alternative organic binders, pre-deposited selenium layers, non-binder recipes helps to avoid the carbon layer although the obtained layers are inhomogeneous and contain impurity phases. A patent for the ion-exchange approach is pending, and the obtained research results on the paste coating approach will be scrutinized during new European FP7 project 'NOVA-CIGS'. (authors)

  10. Preparations for low-cost silica substrate of CIGS solar cell

    Science.gov (United States)

    Hsu, Ming-Seng; Chang, Chung Chih; Cheng, Hsiang Hshi; Ouyang, Yueh; Der Sheu, Shinn

    2008-08-01

    The production of CuInGaSe2 (CIGS) solar cell is based on vacuum processes, which requires a high manufacturing temperature and high cost. Our result show a simple method has been developed to prepare the silica substrates of CIGS solar cell. It's synthesized by sol-gel process from tetraethylorthosilicate (TEOS), methanol (CH3OH) and pure water (both ion-exchange and distillation) in the presence of ammonia as catalyst. The preparation procedure was elaborated as the flexible sequence to control chemical composition and properties of the particles in sol-gel-derived silica substrate. The morphology, particle size, and size distribution of CIGS substrate were characterized with dynamic light scattering (DLS) and atomic force microscopy (AFM). The results of AFM morphology and statistic evidence we find an easy way, non-vacuum and low temperature processes, to successfully prepare the CIGS solar cell substrates with surface roughness below 3 nm. It is powerful the advance study in low cost solar cell.

  11. New buffer layer materials for CIGS solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Gruhn, Thomas; Felser, Claudia [Institute of Inorganic and Analytical Chemistry, Johannes Gutenberg University, Mainz (Germany); Kieven, David [Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Berlin (Germany)

    2009-07-01

    The compound semiconductor CuIn{sub x}Ga{sub (1-x)}Se{sub 2} (CIGSE) are used as absorber material in thin-film photovoltaic cells. In conventional CIGSE based solar cells a thin CdS layer (buffer) significantly improves the photovoltaic performance and efficiencies up to 19.9% have been realized. Since Cd is a toxic heavy metal there is a demand for suitable substitute materials. The first requirements for these materials are an adequate band gap, a crystal structure compatible to that of CIGSE, and an n-type conductivity. An interesting class of materials are half-Heuslers, which are ternary compounds with a C1b MgAgAs structure. For many half-Heusler compounds the crystal structure matches well with the layer of the tetragonal CIGS unit cell. Using ab initio calculations based on B3LYP hybrid functionals, we have studied electronic properties of the most promising half-Heusler materials. Our results affirm the band gap rule for 8-electron half- Heuslers presented.

  12. 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.

  13. Characterization of Al2O3 as CIGS surface passivation layer in high-efficiency CIGS solar cells

    OpenAIRE

    Joel, Jonathan

    2014-01-01

    In this thesis, a novel method of reducing the rear surface recombination in copper indium gallium (di) selenide (CIGS) thin film solar cells, using atomic layer deposited (ALD) Al2O3, has been evaluated via qualitative opto-electrical characterization. The idea stems from the silicon (Si) industry, where rear surface passivation layers are used to boost the open-circuit voltage and, hence, the cell efficiency. To enable a qualitative assessment of the passivation effect, Al/Al2O3/CIGS metal-...

  14. 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.

  15. 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

  16. Fabrication, Electrical Characterization and Simulation of Thin Film Solar Cells: CdTe and CIGS Materials

    OpenAIRE

    Es'haghi Gorji, Nima

    2014-01-01

    CdTe and Cu(In,Ga)Se2 (CIGS) thin film solar cells are fabricated, electrically characterized and modelled in this thesis. We start from the fabrication of CdTe thin film devices where the R.F. magnetron sputtering system is used to deposit the CdS/CdTe based solar cells. The chlorine post-growth treatment is modified in order to uniformly cover the cell surface and reduce the probability of pinholes and shunting pathways creation which, in turn, reduces the series resistance. The deionized wat...

  17. 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.

  18. Degradation of CIGS solar cells due to the migration of alkali-elements

    NARCIS (Netherlands)

    Theelen, M.; Barreau, N.; Hans, V.; Steijvers, H.; Vroon, Z.; Zeman, M.

    2015-01-01

    Non-encapsulated CIGS solar cells with different contents of sodium (Na) and potassium (K) were simultaneously exposed to damp heat and illumination. The solar cells with higher alkali (Na, K) content exhibited higher initial conversion efficiencies, but degraded severely within 100 hours, while sam

  19. 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.

  20. Laser scribing of CIGS thin-film solar cell on flexible substrate

    Science.gov (United States)

    Hwang, David J.; Kuk, Seungkuk; Wang, Zhen; Fu, Shi; Zhang, Tao; Kim, Gayeon; Kim, Won Mok; Jeong, Jeung-hyun

    2017-01-01

    Laser scribing technology has been actively developed for thin-film solar cell fabrication taking a number of advantages over mechanical scribing. Its non-contact processing nature enables reliable and precise scribing processes. In particular, it is almost unavoidable to use laser scribing method for fabricating high-quality flexible thin-film solar cells. Despite the fundamental merits that laser scribing can offer, still a number of challenges should be addressed in order to replace the mechanical counterpart for wider range of thin-film solar cells. In this study, we explore optimal laser scribing conditions for copper-indium-gallium-selenide (CIGS) thin-film solar cells, especially based on flexible polyimide (PI) substrate in close comparison with that based on soda-lime glass substrate. Picosecond-pulsed laser of repetition rate up to 100 kHz and wavelength of 532 nm ( 12 ps temporal pulse width) was mainly tested, and scribing speed in the range of 0.01-1 m/s was examined with a few different laser focal spot diameters (27, 34, and 62 μm). Main focus of this study is in understanding distinct laser scribing mechanisms for flexible substrate configurations, thereby finding out intrinsic optimal processing parameters. One of the most critical requirements is to prevent possible damage or deformation of underlying thin-film layer(s) or PI substrate. Effect of microstructures of thin films (in particular, Mo and CIGS) on the scribing behavior was also examined. In order to further improve the performance of the scribing process and reduce the laser power budget as well, mild gas injection scheme was tested.

  1. Designing novel thin film polycrystalline solar cells for high efficiency: sandwich CIGS and heterojunction perovskite

    Science.gov (United States)

    Wang, Tianyue; Chen, Jiewei; Wu, Gaoxiang; Song, Dandan; Li, Meicheng

    2017-01-01

    Heterojunction and sandwich architectures are two new-type structures with great potential for solar cells. Specifically, the heterojunction structure possesses the advantages of efficient charge separation but suffers from band offset and large interface recombination; the sandwich configuration is favorable for transferring carriers but requires complex fabrication process. Here, we have designed two thin-film polycrystalline solar cells with novel structures: sandwich CIGS and heterojunction perovskite, referring to the advantages of the architectures of sandwich perovskite (standard) and heterojunction CIGS (standard) solar cells, respectively. A reliable simulation software wxAMPS is used to investigate their inherent characteristics with variation of the thickness and doping density of absorber layer. The results reveal that sandwich CIGS solar cell is able to exhibit an optimized efficiency of 20.7%, which is much higher than the standard heterojunction CIGS structure (18.48%). The heterojunction perovskite solar cell can be more efficient employing thick and doped perovskite films (16.9%) than these typically utilizing thin and weak-doping/intrinsic perovskite films (9.6%). This concept of structure modulation proves to be useful and can be applicable for other solar cells. Project supported by the National High-Tech R&D Program of China (No. 2015AA034601), the National Natural Science Foundation of China (Nos. 91333122, 61204064, 51202067, 51372082, 51402106, 11504107), the Ph.D. Programs Foundation of Ministry of Education of China (Nos. 20120036120006, 20130036110012), the Par-Eu Scholars Program, and the Fundamental Research Funds for the Central Universities.

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. Effects of Voltage-Bias Annealing on Metastable Defect Populations in CIGS and CZTSe Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Harvey, Steven P.; Johnston, Steve; Teeter, Glenn

    2016-11-21

    We report on voltage-bias annealing (VBA) experiments performed on CIGS and CZTSe solar cells. In these experiments, completed devices were annealed at moderate temperatures and subsequently quenched with continuously applied voltage bias. These treatments resulted in substantial reversible changes in device characteristics. Photovoltaic (PV) conversion efficiency of the CIGS device varied from below 3% to above 15%, with corresponding changes in CIGS hole density from ~1014 cm-3 to ~1017 cm-3. In the CZTSe device, open-circuit voltage varied from 289 meV to 446 meV, caused by an approximately factor of fifty change in the CZTSe hole density. We interpret these findings in terms of reversible changes to the metastable point-defect populations that control key properties in these materials. Implications for optimization of PV materials and connections to long-term stability of PV devices are discussed.

  7. Improving Efficiency of Multicrystalline Silicon and CIGS Solar Cells by Incorporating Metal Nanoparticles

    Directory of Open Access Journals (Sweden)

    Ming-Jer Jeng

    2015-10-01

    Full Text Available This work studies the use of gold (Au and silver (Ag nanoparticles in multicrystalline silicon (mc-Si and copper-indium-gallium-diselenide (CIGS solar cells. Au and Ag nanoparticles are deposited by spin-coating method, which is a simple and low cost process. The random distribution of nanoparticles by spin coating broadens the resonance wavelength of the transmittance. This broadening favors solar cell applications. Metal shadowing competes with light scattering in a manner that varies with nanoparticle concentration. Experimental results reveal that the mc-Si solar cells that incorporate Au nanoparticles outperform those with Ag nanoparticles. The incorporation of suitable concentration of Au and Ag nanoparticles into mc-Si solar cells increases their efficiency enhancement by 5.6% and 4.8%, respectively. Incorporating Au and Ag nanoparticles into CIGS solar cells improve their efficiency enhancement by 1.2% and 1.4%, respectively. The enhancement of the photocurrent in mc-Si solar cells is lower than that in CIGS solar cells, owing to their different light scattering behaviors and material absorption coefficients.

  8. Improving Efficiency of Multicrystalline Silicon and CIGS Solar Cells by Incorporating Metal Nanoparticles

    OpenAIRE

    Ming-Jer Jeng; Zih-Yang Chen; Yu-Ling Xiao; Liann-Be Chang; Jianping Ao; Yun Sun; Ewa Popko; Witold Jacak; Lee Chow

    2015-01-01

    This work studies the use of gold (Au) and silver (Ag) nanoparticles in multicrystalline silicon (mc-Si) and copper-indium-gallium-diselenide (CIGS) solar cells. Au and Ag nanoparticles are deposited by spin-coating method, which is a simple and low cost process. The random distribution of nanoparticles by spin coating broadens the resonance wavelength of the transmittance. This broadening favors solar cell applications. Metal shadowing competes with light scattering in a manner that varies w...

  9. 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.

  10. 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.

  11. 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).

  12. 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.

  13. Photovoltaic manufacturing cost and throughput improvements for thin-film CIGS-based modules: Phase 1 technical report, July 1998--July 1999

    Energy Technology Data Exchange (ETDEWEB)

    Wiedeman, S.; Wendt, R.G.

    2000-03-01

    The primary objectives of the Global Solar Energy (GSE) Photovoltaic Manufacturing Technology (PVMaT) subcontract are directed toward reducing cost and expanding the production rate of thin-film CuInGaSe{sub 2} (CIGS)-based PV modules on flexible substrates. Improvements will be implemented in monolithic integration, CIGS deposition, contact deposition, and in-situ CIGS control and monitoring. In Phase 1, GSE has successfully attacked many of the highest risk aspects of each task. All-laser, selective scribing processes for CIGS have been developed, and many end-of-contract goals for scribing speed have been exceeded in the first year. High-speed ink-jet deposition of insulating material in the scribes now appears to be a viable technique, again exceeding some end-of-contract goals in the first year. Absorber deposition of CIGS was reduced corresponding to throughput speeds of up to 24-in/min, also exceeding an end-of-contract goal. Alternate back-contact materials have been identified that show potential as candidates for replacement of higher-cost molybdenum, and a novel, real-time monitoring technique (parallel-detector spectroscopic ellipsometry) has shown remarkable sensitivity to relevant properties of the CIGS absorber layer for use as a diagnostic tool. Currently, one of the bilayers has been baselined by GSE for flexible CIGS on polymeric substrates. Resultant back-contacts meet sheet-resistance goals and exhibit much less intrinsic stress than Mo. CIGS has been deposited, and resultant devices are comparable in performance to pure Mo back-contacts. Debris in the chamber has been substantially reduced, allowing longer roll-length between system cleaning.

  14. Stability of TCO window layers for thin-film CIGS solar cells upon damp heat exposures: part II

    Science.gov (United States)

    Sundaramoorthy, R.; Pern, F. J.; DeHart, C.; Gennett, T.; Meng, F. Y.; Contreras, M.; Gessert, T.

    2009-08-01

    Long-term performance reliability is essential for any photovoltaic module to become established in the PV market. Reliability is characterized based on many factors, one of the most important being the capability of the module to be resistant to moisture at elevated temperatures. This work continues our efforts to search for a high-performance and high-stability transparent conducting oxide (TCO) window layer for CuInGaSe2 (CIGS) devices. In this experimental study, we compared the optical, electrical, and structural stability of various TCOs deposited on glass, including single-layer Al-doped ZnO (AZO), bilayer intrinsic-/Al-doped ZnO (BZO), B-doped ZnO (ZnO:B), amorphous In2O3:SnO2 (ITO), and amorphous In2O3:ZnO (IZO). The samples were exposed to damp heat (DH) at 85°C and 85% relative humidity (RH) and were characterized periodically. The results showed that all ZnO-based TCOs are more sensitive to moisture with substantial electrical degradation and apparent optical changes than the ITO and IZO. The amorphous IZO showed peculiar behavior in electrical property, and exhibited structural change with the appearance of some finite crystallinity after DH >220 h. The results from this experimental series will assist in determining the best-performing TCO for CIGS solar cells.

  15. One-pot electrodeposition, characterization and photoactivity of stoichiometric copper indium gallium diselenide (CIGS) thin films for solar cells.

    Science.gov (United States)

    Harati, Mohammad; Jia, Jia; Giffard, Kévin; Pellarin, Kyle; Hewson, Carly; Love, David A; Lau, Woon Ming; Ding, Zhifeng

    2010-12-14

    Herein we report the one-pot electrodeposition of copper indium gallium diselenide, CuIn(1-x)Ga(x)Se(2) (CIGS), thin films as the p-type semiconductor in an ionic liquid medium consisting of choline chloride/urea eutectic mixture known as Reline. The thin films were characterized by scanning electron microscopy with energy dispersive X-ray analysis, transmission electron microscopy, X-ray photoelectron spectroscopy, Raman microspectroscopy, and UV-visible spectroscopy. Based on the results of the characterizations, the electrochemical bath recipe was optimized to obtain stoichiometric CIGS films with x between 0.2 and 0.4. The chemical activity and photoreactivity of the optimized CIGS films were found to be uniform using scanning electrochemical microscopy and scanning photoelectrochemical microscopy. Low-cost stoichiometric CIGS thin films in one-pot were successfully fabricated.

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

    Energy Technology Data Exchange (ETDEWEB)

    Brun, Nadja Rebecca [University of Applied Sciences and Arts Northwestern Switzerland, School of Life Sciences, Gründenstrasse 40, CH-4132 Muttenz (Switzerland); Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, Universitätsstrasse 16, CH-8092 Zürich (Switzerland); Wehrli, Bernhard [Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, Universitätsstrasse 16, CH-8092 Zürich (Switzerland); Fent, Karl, E-mail: karl.fent@fhnw.ch [University of Applied Sciences and Arts Northwestern Switzerland, School of Life Sciences, Gründenstrasse 40, CH-4132 Muttenz (Switzerland); Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, Universitätsstrasse 16, CH-8092 Zürich (Switzerland)

    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{sup −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{sup −1}. From OPV, copper (14 μg L{sup −1}), zinc (87 μg L{sup −1}) and silver (78 μg L{sup −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. - Highlights: • Photovoltaics may be disposed in the environment after usage. • Copper indium gallium selenide (CIGS) and organic (OPV) cells were compared. • Morphological and molecular effects were assessed in zebrafish embryos. • Environmental condition affected metal leaching and ecotoxicological activity. • Damaged CIGS cells pose higher risk to the environment than OPV cells.

  17. 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.

  18. 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

  19. Optimization of CdS Buffer Layer for High Efficiency CIGS Solar Cells.

    Science.gov (United States)

    Kim, Donguk; Jang, Yong-Jun; Jung, Ho-Sung; Kim, Minha; Baek, Dohyun; Yi, Junsin; Lee, Jaehyeong; Choi, Youngkwan

    2016-05-01

    In present work, effects of the thickness on the structural and optical properties of chemically deposited CdS thin films were investigated. In addition, we fabricated Cu(In, Ga)Se2 solar cells with various thicknesses of CdS buffer layer and optimized the thickness for a high efficiency. When the CdS thin films were thicker, the crystallinity improved but the transmittance decreased. The short-circuit current density (J(sc)) and the fill factor are the major efficiency limiting factors for the CIGS solar cells. As the thickness of the CdS buffer layer, the open-circuit voltage (V(oc)) and the fill factor increased, whereas the J(sc) slightly decreased. The improvement of the fill factor and thus efficiency resulted from larger shunt resistance. For the solar cells without a high resistive intrinsic ZnO layer, the highest efficiency was acquired at the thickness of 89 nm. With further increasing the thickness, the J(sc) decreased significantly, resulting in poor efficiency.

  20. 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.

  1. Pulsed Laser Deposition ZnS Buffer Layers for CIGS Solar Cells

    Institute of Scientific and Technical Information of China (English)

    Pai-feng Luo; Guo-shun Jiang; Chang-fei Zhu

    2009-01-01

    Polycrystalline ZnS films were prepared by pulsed laser deposition (PLD) on quartz glass substrates under different growth conditions at different substrate temperatures of 20, 200, 400, and 600 ℃, which is a suitable alternative to chemical bath deposited (CBD) CdS as a buffer layer in Cu(In,Ga)Se2 (CIGS) solar cells. X-ray diffraction studies indicate the films are polycrystalline with zinc-blends structure and they exhibit preferential orientation along the cubic phase β-ZnS (111) direction, which conflicts with the conclusion of wurtzite struc-ture by Murali that the ZnS films deposited by pulse plating technique was polycrystalline with wurtzite structure. The Raman spectra of grown films show A1 mode at approxi-mately 350 cm-1, generally observed in the cubic phase β-ZnS compounds. The planar and the cross-sectional morphology were observed by scanning electron microscopic. The dense, smooth, uniform grains are formed on the quartz glass substrates through PLD technique. The grain size of ZnS deposited by PLD is much smaller than that of CdS by conventional CBD method, which is analyzed as the main reason of detrimental cell performance. The composition of the ZnS films was also measured by X-ray fluorescence. The typical ZnS films obtained in this work are near stoichiometric and only a small amount of S-rich. The energy band gaps at different temperatures were obtained by absorption spectroscopy measurement, which increases from 3.2 eV to 3.7 eV with the increasing of the deposition temperature. ZnS has a wider energy band gap than CdS (2.4 eV), which can enhance the blue response of the photovoltaic cells. These results show the high-quality of these substitute buffer layer materials are prepared through an all-dry technology, which can be used in the manufacture of CIGS thin film solar cells.

  2. 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.

  3. 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

  4. 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

  5. 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.

  6. CIGS thin-film solar module processing: case of high-speed laser scribing

    Science.gov (United States)

    Gečys, Paulius; Markauskas, Edgaras; Nishiwaki, Shiro; Buecheler, Stephan; de Loor, Ronny; Burn, Andreas; Romano, Valerio; Račiukaitis, Gediminas

    2017-01-01

    In this paper, we investigate the laser processing of the CIGS thin-film solar cells in the case of the high-speed regime. The modern ultra-short pulsed laser was used exhibiting the pulse repetition rate of 1 MHz. Two main P3 scribing approaches were investigated - ablation of the full layer stack to expose the molybdenum back-contact, and removal of the front-contact only. The scribe quality was evaluated by SEM together with EDS spectrometer followed by electrical measurements. We also modelled the electrical behavior of a device at the mini-module scale taking into account the laser-induced damage. We demonstrated, that high-speed process at high laser pulse repetition rate induced thermal damage to the cell. However, the top-contact layer lift-off processing enabled us to reach 1.7 m/s scribing speed with a minimal device degradation. Also, we demonstrated the P3 processing in the ultra-high speed regime, where the scribing speed of 50 m/s was obtained. Finally, selected laser processes were tested in the case of mini-module scribing. Overall, we conclude, that the top-contact layer lift-off processing is the only reliable solution for high-speed P3 laser scribing, which can be implemented in the future terawatt-scale photovoltaic production facilities.

  7. CIGS thin-film solar module processing: case of high-speed laser scribing

    Science.gov (United States)

    Gečys, Paulius; Markauskas, Edgaras; Nishiwaki, Shiro; Buecheler, Stephan; De Loor, Ronny; Burn, Andreas; Romano, Valerio; Račiukaitis, Gediminas

    2017-01-01

    In this paper, we investigate the laser processing of the CIGS thin-film solar cells in the case of the high-speed regime. The modern ultra-short pulsed laser was used exhibiting the pulse repetition rate of 1 MHz. Two main P3 scribing approaches were investigated – ablation of the full layer stack to expose the molybdenum back-contact, and removal of the front-contact only. The scribe quality was evaluated by SEM together with EDS spectrometer followed by electrical measurements. We also modelled the electrical behavior of a device at the mini-module scale taking into account the laser-induced damage. We demonstrated, that high-speed process at high laser pulse repetition rate induced thermal damage to the cell. However, the top-contact layer lift-off processing enabled us to reach 1.7 m/s scribing speed with a minimal device degradation. Also, we demonstrated the P3 processing in the ultra-high speed regime, where the scribing speed of 50 m/s was obtained. Finally, selected laser processes were tested in the case of mini-module scribing. Overall, we conclude, that the top-contact layer lift-off processing is the only reliable solution for high-speed P3 laser scribing, which can be implemented in the future terawatt-scale photovoltaic production facilities. PMID:28084403

  8. 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.

  9. Preparation and optimization of a molybdenum electrode for CIGS solar cells

    Directory of Open Access Journals (Sweden)

    Feng Jingxue

    2016-11-01

    Full Text Available Molybdenum (Mo films were deposited by radio frequency (RF, direct current (DC and mixed magnetron sputtering, respectively. With changing the deposition parameters including deposition pressure and power, the films show different surface morphology and crystallinity. Lower resistivity of the films is obtained in the DC mode and better reflectivity of the films is obtained in the RF mode. It is shown that the crystallinity increases when the deposition pressure decreases. The crystallinity and the grain size both increase as the deposition power increasing. The lowest resistivity of the single Mo film is 34×10-6 Ω·cm when the deposition pressure is 0.1 Pa and the deposition power is 300 W in the DC mode. In order to obtain lower resistivity, better adhesion and better reflectivity, bilayer films and tri-layer films were both deposited in different mode. They all show good adhesion and low resistivity. The Mo films deposited in mixed mode show better reflectivity. It is demonstrated that the resistivity of about 65×10-6 Ω·cm is achieved in DC/RF mode and the resistivity of about 61×10-6 Ω·cm is achieved in RF/DC/RF mode. And the tri-layer films achieved in RF/DC/RF mode have better reflectivity than bilayer films achieved in DC/RF mode. The tri-layer films achieved in RF/DC/RF mode is appropriate for using as the electrode of CIGS solar cells.

  10. Suppressing lossy-film-induced angular mismatches between reflectance and transmittance extrema: optimum optical designs of interlayers and AR coating for maximum transmittance into active layers of CIGS solar cells.

    Science.gov (United States)

    Chang, Yin-Jung

    2014-01-13

    The investigation of optimum optical designs of interlayers and antireflection (AR) coating for achieving maximum average transmittance (T(ave)) into the CuIn(1-x)Ga(x)Se2 (CIGS) absorber of a typical CIGS solar cell through the suppression of lossy-film-induced angular mismatches is described. Simulated-annealing algorithm incorporated with rigorous electromagnetic transmission-line network approach is applied with criteria of minimum average reflectance (R(ave)) from the cell surface or maximum T(ave) into the CIGS absorber. In the presence of one MgF2 coating, difference in R(ave) associated with optimum designs based upon the two distinct criteria is only 0.3% under broadband and nearly omnidirectional incidence; however, their corresponding T(ave) values could be up to 14.34% apart. Significant T(ave) improvements associated with the maximum-T(ave)-based design are found mainly in the mid to longer wavelengths and are attributed to the largest suppression of lossy-film-induced angular mismatches over the entire CIGS absorption spectrum. Maximum-T(ave)-based designs with a MgF2 coating optimized under extreme deficiency of angular information is shown, as opposed to their minimum-R(ave)-based counterparts, to be highly robust to omnidirectional incidence.

  11. Fabrication of high-quality ZnS buffer and its application in Cd-free CIGS solar cells

    Science.gov (United States)

    Li, Feng-yan; Dang, Xiang-yu; Zhang, Li; Liu, Fang-fang; Sun, Ding; He, Qing; Li, Chang-jian; Li, Bao-zhang; Zhu, Hong-bing

    2014-07-01

    This paper provides the fabrication of Cd-free Cu(In,Ga)Se2 (CIGS) solar cells on soda-lime glass substrates. A high quality ZnS buffer layer is grown by chemical bath deposition (CBD) process with ZnSO4-NH3-SC (NH2)2 aqueous solution system. The X-ray diffraction (XRD) result shows that the as-deposited ZnS film has cubic (111) and (220) diffraction peaks. Scanning electron microscope (SEM) images indicate that the ZnS film has a dense and compact surface with good crystalline quality. Transmission measurement shows that the optical transmittance is about 90% when the wavelength is beyond 500 nm. The bandgap ( E g ) value of the as-deposited ZnS film is estimated to be 3.54 eV. Finally, a competitive efficiency of 11.06% is demonstrated for the Cd-free CIGS solar cells with ZnS buffer layer after light soaking.

  12. 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.

  13. 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。

  14. 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.

  15. 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

    Energy Technology Data Exchange (ETDEWEB)

    Burghoorn, M.; Kniknie, B.; Deelen, J. van; Ee, R. van [The Netherlands Organisation for Applied Scientific Research (TNO), De Rondom 1, 5612 AP, Eindhoven (Netherlands); Xu, M. [The Netherlands Organisation for Applied Scientific Research (TNO), De Rondom 1, 5612 AP, Eindhoven (Netherlands); Delft University of Technology, Optics Group, Van der Waalsweg 8, 2628 CH, Delft (Netherlands); Vroon, Z. [The Netherlands Organisation for Applied Scientific Research (TNO), De Rondom 1, 5612 AP, Eindhoven (Netherlands); Zuyd Hogeschool, Nieuw Eyckholt 300, 6419 DJ, Heerlen (Netherlands); Belt, R. van de [Kriya Materials BV, Urmonderbaan 22, 6167 RD, Geleen (Netherlands); Buskens, P., E-mail: pascal.buskens@tno.nl, E-mail: buskens@dwi.rwth-aachen.de [The Netherlands Organisation for Applied Scientific Research (TNO), De Rondom 1, 5612 AP, Eindhoven (Netherlands); DWI – Leibniz Institute for Interactive Materials, Forckenbeckstrasse 50, 52056, Aachen (Germany)

    2014-12-15

    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 (J{sub sc}) 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 J{sub sc} and efficiency of CIGS solar cells with an absorber layer thickness (d{sub CIGS}) 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 (n{sub resist} = 1.792 vs. n{sub AZO} = 1.913 at 633 nm) to avoid large optical losses at the resist-AZO interface. On average, J{sub sc} 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 J{sub sc} with decreasing d{sub CIGS} was observed. Ergo, the increase in J{sub sc} can be fully explained by the reduction in reflection, and we did not observe any increase in J{sub sc} based on an increased photon path length.

  16. 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

    Science.gov (United States)

    Burghoorn, M.; Kniknie, B.; van Deelen, J.; Xu, M.; Vroon, Z.; van Ee, R.; van de Belt, R.; Buskens, P.

    2014-12-01

    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.

  17. 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.

  18. 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.

  19. Highly efficient graphene-based Cu(In, Ga)Se₂ solar cells with large active area.

    Science.gov (United States)

    Yin, Ling; Zhang, Kang; Luo, Hailin; Cheng, Guanming; Ma, Xuhang; Xiong, Zhiyu; Xiao, Xudong

    2014-09-21

    Two-dimensional graphene has tremendous potential to be used as a transparent conducting electrode (TCE), owing to its high transparency and conductivity. To date graphene films have been applied to several kinds of solar cells except the Cu(In, Ga)Se₂ (CIGS) solar cell. In this work, we present a novel TCE structure consisting of a doped graphene film and a thin layer of poly(methyl methacrylate) (PMMA) to replace the ZnO:Al (AZO) electrode for CIGS. By optimizing the contact between graphene and intrinsic ZnO (i-ZnO), a high power conversion efficiency (PCE) of 13.5% has been achieved, which is among the highest efficiencies of graphene-based solar cells ever reported and approaching those of AZO-based solar cells. Besides, the active area of our solar cells reaches 45 mm(2), much larger than other highly efficient graphene-based solar cells (>10%) reported so far. Moreover, compared with AZO-based CIGS solar cells, the total reflectance of the graphene-based CIGS solar cells is decreased and the quantum efficiency of the graphene-based CIGS is enhanced in the near infrared region (NIR), which strongly support graphene as a competitive candidate material for the TCE in the CIGS solar cell. Furthermore, the graphene/PMMA film can protect the solar cell from moisture, making the graphene-based solar cells much more stable than the AZO-based solar cells.

  20. 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.

  1. 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.

  2. Adhesion, resistivity and structural, optical properties of molybdenum on steel sheet coated with barrier layer done by sol–gel for CIGS solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Amouzou, Dodji, E-mail: dodji.amouzou@fundp.ac.be [Research Centre in Physics of Matter and Radiation (PMR), University of Namur (FUNDP), Rue de Bruxelles 61, 5000 Namur (Belgium); Dumont, Jacques [Research Centre in Physics of Matter and Radiation (PMR), University of Namur (FUNDP), Rue de Bruxelles 61, 5000 Namur (Belgium); Fourdrinier, Lionel; Richir, Jean-Baptiste; Maseri, Fabrizio [CRM-Group, Boulevard de Colonster, B 57, 4000 Liège (Belgium); Sporken, Robert [Research Centre in Physics of Matter and Radiation (PMR), University of Namur (FUNDP), Rue de Bruxelles 61, 5000 Namur (Belgium)

    2013-03-01

    Molybdenum films are investigated on stainless steel substrates coated with polysilazane based sol–gel and SiO{sub x} layers for flexible CIGS solar cell applications. Thermal stability of the multilayer has been studied. The thickness of polysilazane films are significantly reduced (17%) after heat treatment suggesting a thermal degradation. Four different microstructures were found for Mo films by varying argon total pressure from 2.6 × 10{sup −1} Pa to 2.6 Pa. It was shown that continuous films, low sheet resistance (0.5 Ω/□) and well facetted grains can be achieved when Mo films are deposited on heated substrates at homologous temperature, T of 0.2. - Highlights: ► Steel sheet is functionalized for Cu[Inx,Ga(1 − x)Se2] solar cells. ► Varying deposition pressure impacts the microstructure of Mo films. ► High thermal stability of the sol gel based barrier layer has been investigated. ► Low sheet resistance and continuous Mo films have been obtained at 550°C. ► Thermal stability of functionalized steel sheets at 550°C has been investigated.

  3. 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.

  4. DLTS Characterization of CIGS Cells

    Energy Technology Data Exchange (ETDEWEB)

    Kerr, L. L.; Li, S. S.; Anderson, T. J.; Crisalle, O. D.; Johnston, S.; Abushama, J.; Noufi, R.

    2003-06-01

    Deep Level Transient Spectroscopy (DLTS) and Capacitance-Voltage (C-V) measurements are employed to study deep-level electron and hole traps in CIGS solar cells fabricated at two different locations (EPV and NREL). The activation energy and trap density as well as suggested defect origins are given.

  5. CIGS Material and Device Stability: A Processing Perspective (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Ramanathan, K.

    2012-03-01

    This is a general overview of CIGS material and device fundamentals. In the first part, the basic features of high efficiency CIGS absorbers and devices are described. In the second part, some examples of previous collaboration with Shell Solar CIGSS graded absorbers and devices are shown to illustrate how process information was used to correct deviations and improve the performance and stability.

  6. New Materials for Chalcogenide Based Solar Cells

    Science.gov (United States)

    Tosun, Banu Selin

    Thin film solar cells based on copper indium gallium diselenide (CIGS) have achieved efficiencies exceeding 20 %. The p-n junction in these solar cells is formed between a p-type CIGS absorber layer and a composite n-type film that consists of a 50-100 nm thin n-type CdS followed by a 50-200 nm thin n-type ZnO. This dissertation focuses on developing materials for replacing CdS and ZnO films to improve the damp-heat stability of the solar cells and for minimizing the use of Cd. Specifically, I demonstrate a new CIGS solar cell with better damp heat stability wherein the ZnO layer is replaced with SnO2. The efficiency of solar cells made with SnO2 decreased less than 5 % after 120 hours at 85 °C and 85 % relative humidity while the efficiency of solar cells made with ZnO declined by more than 70 %. Moreover, I showed that a SnO2 film deposited on top of completed CIGS solar cells significantly increased the device lifetime by forming a barrier against water diffusion. Semicrystalline SnO2 films deposited at room temperature had nanocrystals embedded in an amorphous matrix, which resulted in films without grain boundaries. These films exhibited better damp-heat stability than ZnO and crystalline SnO2 films deposited at higher temperature and this difference is attributed to the lack of grain boundary water diffusion. In addition, I studied CBD of Zn1-xCdxS from aqueous solutions of thiourea, ethylenediaminetetraacetic acid and zinc and cadmium sulfate. I demonstrated that films with varying composition (x) can be deposited through CBD and studied the structure and composition variation along the films' thickness. However, this traditional chemical bath deposition (CBD) approach heats the entire solution and wastes most of the chemicals by homogenous particle formation. To overcome this problem, I designed and developed a continuous-flow CBD approach to utilize the chemicals efficiently and to eliminate homogenous particle formation. Only the substrate is heated to

  7. Synthesis of colloidal nanoscaled copper-indium-gallium-selenide (CIGS) particles for photovoltaic applications.

    Science.gov (United States)

    Mousavi, S H; Müller, T S; de Oliveira, P W

    2012-09-15

    In this work, Cu(In,Ga)Se(2) (CIGS) nanoparticles were synthesized using a wet chemical method. The method is based on a non-vacuum thermal process that does not use selenization. The effects of temperature, source materials, and growth conditions on the phase and particle size were investigated. X-ray diffraction results confirm the formation of a tetragonal CIGS structure as the main phase with the purity more than 99% obtained by energy-dispersive X-ray spectroscopy (EDX). The morphology and size of the samples were investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Using these methods, 20-80nm particles were obtained. Through measurements of the absorption spectra of CIGS nanoparticles, the band gap of the synthesized material was determined to be about 1.44eV, which corresponds to an acceptable wavelength region for absorber layers in solar cells.

  8. 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.

  9. Characterization of 19.9% Efficient CIGS Absorbers: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Repins, I.; Contreras, M.; Romero, M.; Yan, Y.; Metzger, W.; Li, J.; Johnston, S.; Egass, B.; DeHart, C.; Scharf, J.; McCandless, B. E.; Noufi, R.

    2008-05-01

    This paper documents the properties of the world-record-efficiency CIGS solar cell by a variety of characterization techniques, with an emphasis on identifying near-surface properties associated with the modified processing.

  10. 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.

  11. 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.

  12. Alternative bufferlayers for CIGS solarcells

    Energy Technology Data Exchange (ETDEWEB)

    Beleanu, A.; Gruhn, T.; Blum, C.G.F.; Balke, B.; Felser, C. [Institute of Inorganic and Analytical Chemistry, Johannes Gutenberg - University, Mainz (Germany)

    2010-07-01

    Cadmium sulfide is a highly efficient buffer layer material in Cu(In,Ga)(S,Se2)[CIGS] solar devices, but for environmental reasons and possible gains in efficiency there is a great interest in replacing CdS by a cadmium-free alternative buffer layer. Using standard density functional theory (DFT) methods possible candidates like LiZnP and LiCuS have been proposed as alternative buffer layers. The experimental verification of the DFT results was quite challenging due to the fact that LiCuS was an unknow and completely new material. In a first step, we tried to synthesize LiCuS through solid state reactions in a corund crucible. After optimizing the parameters and successfully synthesizing the material its properties were investigated. In a second step, huge amounts of LiCuS and LiZnP were synthesized and pressed using Spark Plasma Sintering as 3 inch targets. LiCuS and LiZnP films were grown by radio-frequency magnetron sputtering from these target and their properties as an alternative buffer layer in CIGS solar cells were investigated. The 1:1:1 stoichiometry of the films was delivered from in-situ XPS measurements. Absorption measurements show a band gap of {approx}2.0 eV which is in good agreement with the theoretical estimates.

  13. 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.

  14. Metal-assisted chemical etching of CIGS thin films for grain size analysis

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Chaowei [Research and Development Centre, Hanergy Thin Film Power Group Limited, Chengdu (China); Loi, Huu-Ha; Duong, Anh; Parker, Magdalena [Failure Analysis Department, MiaSole Hi-Tech Corp., Santa Clara, CA (United States)

    2016-09-15

    Grain size of the CIGS absorber is an important monitoring factor in the CIGS solar cell manufacturing. Electron backscatter diffraction (EBSD) analysis is commonly used to perform CIGS grain size analysis in the scanning electron microscope (SEM). Although direct quantification on SEM image using the average grain intercept (AGI) method is faster and simpler than EBSD, it is hardly applicable on CIGS thin films. The challenge is that, not like polycrystalline silicon, to define grain boundaries by selective chemical etching is not easily realizable for the multi-component CIGS alloy. In this Letter, we present direct quantification of CIGS thin film grain size using the AGI method by developing metal-assisted wet chemical etching process to define CIGS grain boundaries. The calculated value is similar to EBSD result. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. 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.

  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. ETUDE ET SIMULATION DE CELLULES PHOTOVOLTAIQUES A COUCHES MINCES A BASE DE CIS et CIGS

    OpenAIRE

    MOSTEFA KARA, Selma

    2012-01-01

    Dans le contexte global de la diversification de l’utilisation des ressources naturelles, le recours aux énergies renouvelables et en particulier le solaire photovoltaïque se fait de plus en plus fort. A ce titre, le développement d’une nouvelle génération de cellules photovoltaïques à base de Cu(In,Ga)Se2 semble prometteur. En effet, le rendement de ces cellules a dépassé les 20% ces dernières années. Dans ce travail de modélisation et de simulation, nous utilisons le logiciel Si...

  18. 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.

  19. High throughput CIGS solar cell fabrication via ultra-thin absorber layer with optical confinement and (Cd, CBD)-free heterojunction partner

    Energy Technology Data Exchange (ETDEWEB)

    Marsillac, Sylvain [Old Dominion Univ., Norfolk, VA (United States)

    2015-11-30

    The main objective of this proposal was to use several pathways to reduce the production cost of Cu(In,Ga)Se2 (CIGS) PV modules and therefore the levelized cost of energy (LCOE) associated with this technology. Three high cost drivers were identified, nominally: 1) Materials cost and availability; 2) Large scale uniformity; 3) Improved throughput These three cost drivers were targeted using the following pathways: 1) Reducing the thickness of the CIGS layer while enhancing materials quality; 2) Developing and applying enhanced in-situ metrology via real time spectroscopic ellipsometry; 3) Looking into alternative heterojunction partner, back contact and anti-reflection (AR) coating Eleven main Tasks were then defined to achieve these goals (5 in Phase 1 and 6 in Phase 2), with 11 Milestones and 2 Go/No-go decision points at the end of Phase 1. The key results are summarized below

  20. Inkjet printed Cu(In,Ga)S2 nanoparticles for low-cost solar cells

    Science.gov (United States)

    Barbé, Jérémy; Eid, Jessica; Ahlswede, Erik; Spiering, Stefanie; Powalla, Michael; Agrawal, Rakesh; Del Gobbo, Silvano

    2016-12-01

    Cu(In,Ga)Se2 (CIGSe) thin film solar cells were fabricated by direct inkjet printing of Cu(In,Ga)S2 (CIGS) nanoparticles followed by rapid thermal annealing under selenium vapor. Inkjet printing is a low-cost, low-waste, and flexible patterning method which can be used for deposition of solution-based or nanoparticle-based CIGS films with high throughput. XRD and Raman spectra indicate that no secondary phase is formed in the as-deposited CIGS film since quaternary chalcopyrite nanoparticles are used as the base solution for printing. Besides, CIGSe films with various Cu/(In + Ga) ratios could be obtained by finely tuning the composition of CIGS nanoparticles contained in the ink, which was found to strongly influence the devices performance and film morphology. To date, this is the first successful fabrication of a solar device by inkjet printing of CIGS nanoparticles.

  1. Inkjet printed Cu(In,Ga)S2 nanoparticles for low-cost solar cells

    KAUST Repository

    Barbe, Jeremy

    2016-12-13

    Cu(In,Ga)Se2 (CIGSe) thin film solar cells were fabricated by direct inkjet printing of Cu(In,Ga)S2 (CIGS) nanoparticles followed by rapid thermal annealing under selenium vapor. Inkjet printing is a low-cost, low-waste, and flexible patterning method which can be used for deposition of solution-based or nanoparticle-based CIGS films with high throughput. XRD and Raman spectra indicate that no secondary phase is formed in the as-deposited CIGS film since quaternary chalcopyrite nanoparticles are used as the base solution for printing. Besides, CIGSe films with various Cu/(In + Ga) ratios could be obtained by finely tuning the composition of CIGS nanoparticles contained in the ink, which was found to strongly influence the devices performance and film morphology. To date, this is the first successful fabrication of a solar device by inkjet printing of CIGS nanoparticles.

  2. Studies on chemical bath deposited CdS buffer layers for CIGS thin film solar cells%CIGS薄膜太阳能电池缓冲层CdS薄膜的制备研究

    Institute of Scientific and Technical Information of China (English)

    何丽秋

    2016-01-01

    目前CdS材料的制备方法有很多种,但是最常用的是化学水浴法。本文研究了浓度、反应溶液pH值、温度、沉积时间对CdS缓冲层薄膜的影响,对CIGS薄膜太阳能电池缓冲层CdS薄膜的制备方法进行了论述。%At present,the preparation methods of CdS has many kinds,The chemical bath deposition(CBD)is the most commonly method.In this review,the effects of concentration,pH,temperature and deposition time on the CdS buffer layer were studied.The preparation methods of CIGS thin film for CdS thin film solar cells were discussed.

  3. Bulk measurement of copper and sodium content in CuIn(0.7)Ga(0.3)Se(2) (CIGS) solar cells with nanosecond pulse length laser induced breakdown spectroscopy (LIBS)

    CERN Document Server

    Kowalczyk, Jeremy M D; DeAngelis, Alexander; Kaneshiro, Jess; Mallory, Stewart A; Chang, Yuancheng; Gaillard, Nicolas

    2013-01-01

    In this work, we show that laser induced breakdown spectroscopy (LIBS) with a nanosecond pulse laser can be used to measure the copper and sodium content of CuIn(0.7)Ga(0.3)Se(2) (CIGS) thin film solar cells on molybdenum. This method has four significant advantages over methods currently being employed: the method is inexpensive, measurements can be taken in times on the order of one second, without high vacuum, and at distances up to 5 meters or more. The final two points allow for in-line monitoring of device fabrication in laboratory or industrial environments. Specifically, we report a linear relationship between the copper and sodium spectral lines from LIBS and the atomic fraction of copper and sodium measured via secondary ion mass spectroscopy (SIMS), discuss the ablation process of this material with a nanosecond pulse laser compared to shorter pulse duration lasers, and examine the depth resolution of nanosecond pulse LIBS.

  4. 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.

  5. Study on the Distance Optimization Between Laser Scribing Lines in CIGS Solar Module%铜铟镓硒薄膜组件激光刻线最佳间距的研究

    Institute of Scientific and Technical Information of China (English)

    彭寿; 王丛笑; 杨卫明; 傅干华; 王伟; 吴美平

    2016-01-01

    通过建立数学模型推导出以有效工作区宽度w为参数的功率损失方程,根据铜铟镓硒薄膜和导电膜的实际电学参数计算出了优化的w值,从而得到最佳激光刻线间距为5.56 mm,进一步研究了铜铟镓硒薄膜组件激光刻线间距对输出功率损失的影响。%An active area width as w based power loss equation is deduced by setting up a mathematic model.Based on the real electrical parameters of CIGS and the transparent conductive oxide thin film,the optimized w is calculated, and the optimized distance of 5 .5 6 mm between laser scribing lines is also calculated.The impact of power loss due to the distance between laser scribing lines in CIGS module is investigated.

  6. Solar Cells Based on Low-dimensional Nanocomposite Structures

    Directory of Open Access Journals (Sweden)

    S.L. Khrypko

    2016-12-01

    Full Text Available Converting solar energy into electric energy with using of solar batteries is a major task for developers and research teams. In this article we will look at the development of different generations of solar batteries for to create a nanocomposite structure. Production of solar batteries has gone through some steps, taking into account technological and economic aspects that have been associated with improved of their parameters. Thus the first generations of solar batteries have been based on the single-crystal silicon substrates (с-Si. The use of polycrystalline silicon and multi- crystalline allowed lower costs of modules, but due to the efficiency of solar energy conversion. The solar batteries of the second generation were based on thin-film technology, in which use different materials: silicon films based on amorphous silicon (a-Si, a film based on cadmium telluride (CdTe and film selenide copper-indium-gallium (CuInGaSe2, or CIGS. The use of such technology has allowed increasing the coefficient of performance (COP solar cell with a significant reduction in costs. The solar batteries of third-generation based on nanotechnology, nanocrystals and nano-sized clusters of semiconductors. The creation of such solar cells requires availability of a low-dimensional composite structure. Low-dimensional nanocomposite structures that are constructed on quantum dots and nano-porous materials have new modified optoelectronic properties. They can be used in solar elements, where absorption bands can be optimally adapted to the wavelength of radiation light. These structures could theoretically can lead to increased efficiency of solar energy conversion more than 65%, which can double practically current efficiency of solar batteries.

  7. Revised positions for the CIG galaxies

    CERN Document Server

    Leon, S

    2003-01-01

    We present revised positions for the 1051 galaxies belonging to the Karachentseva Catalog of Isolated Galaxies (CIG). New positions were calculated by applying SExtractor to the Digitized Sky Survey CIG fields with a spatial resolution of 1.2''. We visually checked the results and for 118 galaxies had to recompute the assigned positions due to complex morphologies (e.g. distorted isophotes, undefined nuclei, knotty galaxies) or the presence of bright stars. We found differences between older and newer positions of up to 38'' with a mean value of 2.96'' relative to SIMBAD and up to 38'' and 2.42'' respectively relative to UZC. Based on star positions from the APM catalog we determined that the DSS astrometry of five CIG fields has a mean offset in (RA, Dec) of (-0.90'',0.93'') with a dispersion of 0.4''. These results have been confirmed using the 2MASS All-Sky Catalog of Point Sources. The intrinsic errors of our method combined with the astrometric ones are of the order of 0.5''.

  8. 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

  9. Research on fabrication technology for thin film solar cells for practical use. Technological development for qualitative improvement (CuInSe2 based PV cell); Usumaku taiyo denchi seizo gijutsu no jitsuyoka kenkyu. Kohinshitsuka gijutsu (CuInSe2 taiyo denchi seizo no gijutsu kaihatsu)

    Energy Technology Data Exchange (ETDEWEB)

    Tatsuta, M. [New Energy and Industrial Technology Development Organization, Tokyo (Japan)

    1994-12-01

    This paper reports the study results on the fabrication technology of CuInSe2 based PV cell in fiscal 1994. (1) On formation of high-quality CIGS thin films by bilayer method, Mo film was deposited on a glass substrate by sputtering, and CIGS film with different Ga/In ratios was next formed on the substrate by quaternary simultaneous deposition at different In and Ga deposition speeds. In addition, CdS film was deposited on the CIGS film, and ZnO and ITO films were finally deposited on it by sputtering to complete solar cell. This solar cell offered the maximum conversion efficiency among cells using CIGS film. (2) On formation of high-quality CIGS thin films by three-stage method, a certain correlation was found between substrate temperature and CIGS film composition by monitoring substrate temperature in film forming process. This phenomenon allowed rigorous control of CIS film compositions important for CIS thin film solar cells. (3) On low-cost process technology for thin film formation, Cu(In,Ga)S2 solid solution film was fabricated by expanded selenic process. 3 figs.

  10. Modeling and simulation of CuIn1-xGaxSe2 based thin film solar cell

    Science.gov (United States)

    Kumari, S.; Singh, P.; Gautam, R.; Verma, A. S.

    2014-04-01

    In this work, CIGS (Copper Indium Gallium Diselenide) based solar cell structure has been simulated. We have been calculated short circuit current, open circuit voltage and efficiency of the cell. The thickness of the absorption layer is varied from 400 to 3000 nm, keeping the thickness of other layers unchanged. The effect of absorption layer thickness over cell performance has been analyzed and found that the efficiency increases upto 22% until the thickness of the absorption layer reaches around 2000 nm.

  11. 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.

  12. Synchrotron X-Ray Characterization of Alkali Elements at Grain Boundaries in Cu(In, Ga)Se2 Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    West, Bradley; Stuckelberger, Michael; Guthrey, Harvey; Chen, Lei; Lai, Barry; Maser, Jorg; Rose, Volker; Dynes, James J.; Shafarman, William; Al-Jassim, Mowafak; Bertoni, Mariana I.

    2016-11-21

    It is well known that the addition of alkali elements such as Na and K during and after growth of Cu(In, Ga)Se2 (CIGS) has beneficial effects on the electronic properties of bulk material, improving device performance significantly. While the device level effects have been measured and reported, a direct observations of the localization of Na including its chemical nature are missing, and the impact of Na on elemental and phase segregation during CIGS growth is not fully understood. We investigate these aspects to shine light on the role of Na in CIGS solar cells with the ultimate goal of increasing their conversion efficiency. Utilizing a suite of synchrotron based x-ray characterization techniques, we discuss the challenges and advantages of these techniques for investigating segregation of main constituents of CIGS, Na distribution, chemical bonding of Na, and collection efficiency in CIGS as well as their correlations.

  13. 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.

  14. Numerical Analysis of Copper-Indium-Gallium-Diselenide-Based Solar Cells by SCAPS-1D

    Directory of Open Access Journals (Sweden)

    S. Ouédraogo

    2013-01-01

    Full Text Available We used a one-dimensional simulation program Solar Cell Capacitance Simulator in 1 Dimension (SCAPS-1D to investigate Copper-Indium-Gallium-Diselenide- (CIGS- based solar cells properties. Starting with a conventional ZnO-B/i-ZnO/CdS/CIGS structure, we simulated the parameters of current-voltage characteristics and showed how the absorber layer thickness, hole density, and band gap influence the short-circuit current density (Jsc, open-circuit voltage (Voc, fill factor (FF, and efficiency of solar cell. Our simulation results showed that all electrical parameters are greatly affected by the absorber thickness (w below 1000 nm, due to the increase of back-contact recombination and very poor absorption. Increasing hole density (p or absorber band gap (Eg improves Voc and leads to high efficiency, which equals value of 16.1% when p = 1016 cm−3 and Eg=1.2 eV. In order to reduce back-contact recombination, the effect of a very thin layer with high band gap inserted near the back contact and acting as electrons reflector, the so-called back-electron reflector (EBR, has been investigated. The performances of the solar cells are significantly improved, when ultrathin absorbers (w < 500 nm are used; the corresponding gain of Jsc due to the EBR is 3 mA/cm2. Our results are in good agreement with those reported in the literature from experiments.

  15. Development of Enhanced Window layers for CIGS Photovoltaic Devices

    Science.gov (United States)

    Alexander, J. Nicholas

    One of the most promising thin film devices right now is the Copper Indium Gallium Selenide (CIGS) solar cell with maximum reported power conversion efficiency of 22.3%. The Transparent Conducting Oxide (TCO) which is the top layer of the CIGS device also known as the window layer, is responsible for collecting the electrons generated in the CIGS device and conducting them to the circuit. Development of a very low resistivity film with a high optical transmission is crucial for optimal performance of devices as well as the ability to be deployed without changes to their properties for several decades. Current TCOs such as indium tin oxide (ITO) and aluminum doped zinc oxide (AZO) are met with limitations with either using large amounts of expensive materials such as indium, often requiring and anneal step to obtain good conductivity, or have shown poor long term reliability. This thesis is focused on development of InZnO and zirconium doped InZnO as a potential replacement TCO to obtain high conductivity and high transmission like the leading TCOs without needing heated depositions, post deposition annealing, and maintain a good film reliability. Zirconium doping was employed to farther enhance both the optical and electrical properties through enhancement of the films high frequency permittivity of InZnO while providing improved reliability to the film. The films were grown through a mix of DC and RF co-sputtering. InZnO films were deposited at varying indium concentration ( 10-30%) and samples were able to achieve low resistivity ( 7x10-4 O-cm), high mobility (>30 cm2/v.s), high carrier concentration (>10 20 cm-3), while maintaining high transmission (> 80%) in the visible and near-infrared region. After zirconium was incorporated into the InZnO films by replacement of the ZnO target with a ZrO2/ZnO (5:95) target, films of Zr:InZnO were deposit through the same method to achieve films that maintained very similar electrical and optical properties. The little

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Computational Infrastructure for Geodynamics (CIG)

    Science.gov (United States)

    Gurnis, M.; Kellogg, L. H.; Bloxham, J.; Hager, B. H.; Spiegelman, M.; Willett, S.; Wysession, M. E.; Aivazis, M.

    2004-12-01

    Solid earth geophysicists have a long tradition of writing scientific software to address a wide range of problems. In particular, computer simulations came into wide use in geophysics during the decade after the plate tectonic revolution. Solution schemes and numerical algorithms that developed in other areas of science, most notably engineering, fluid mechanics, and physics, were adapted with considerable success to geophysics. This software has largely been the product of individual efforts and although this approach has proven successful, its strength for solving problems of interest is now starting to show its limitations as we try to share codes and algorithms or when we want to recombine codes in novel ways to produce new science. With funding from the NSF, the US community has embarked on a Computational Infrastructure for Geodynamics (CIG) that will develop, support, and disseminate community-accessible software for the greater geodynamics community from model developers to end-users. The software is being developed for problems involving mantle and core dynamics, crustal and earthquake dynamics, magma migration, seismology, and other related topics. With a high level of community participation, CIG is leveraging state-of-the-art scientific computing into a suite of open-source tools and codes. The infrastructure that we are now starting to develop will consist of: (a) a coordinated effort to develop reusable, well-documented and open-source geodynamics software; (b) the basic building blocks - an infrastructure layer - of software by which state-of-the-art modeling codes can be quickly assembled; (c) extension of existing software frameworks to interlink multiple codes and data through a superstructure layer; (d) strategic partnerships with the larger world of computational science and geoinformatics; and (e) specialized training and workshops for both the geodynamics and broader Earth science communities. The CIG initiative has already started to

  1. Fabrication of solution processed 3D nanostructured CuInGaS₂ thin film solar cells.

    Science.gov (United States)

    Chu, Van Ben; Cho, Jin Woo; Park, Se Jin; Hwang, Yun Jeong; Park, Hoo Keun; Do, Young Rag; Min, Byoung Koun

    2014-03-28

    In this study we demonstrate the fabrication of CuInGaS₂ (CIGS) thin film solar cells with a three-dimensional (3D) nanostructure based on indium tin oxide (ITO) nanorod films and precursor solutions (Cu, In and Ga nitrates in alcohol). To obtain solution processed 3D nanostructured CIGS thin film solar cells, two different precursor solutions were applied to complete gap filling in ITO nanorods and achieve the desirable absorber film thickness. Specifically, a coating of precursor solution without polymer binder material was first applied to fill the gap between ITO nanorods followed by deposition of the second precursor solution in the presence of a binder to generate an absorber film thickness of ∼1.3 μm. A solar cell device with a (Al, Ni)/AZO/i-ZnO/CdS/CIGS/ITO nanorod/glass structure was constructed using the CIGS film, and the highest power conversion efficiency was measured to be ∼6.3% at standard irradiation conditions, which was 22.5% higher than the planar type of CIGS solar cell on ITO substrate fabricated using the same precursor solutions.

  2. Evidence of p- to n-type inversion at CIGS grain boundaries: A depth-dependent surface electron microscopy study

    Science.gov (United States)

    Chan, Calvin; Ohta, Taisuke; Kellogg, Gary; Mansfield, Lorelle; Noufi, Rommel

    2014-03-01

    Chalcopyrite Cu(In1-xGax)Se2 (CIGS) is an interesting photovoltaic material because it holds the laboratory record for thin-film solar power conversion efficiency (η > 20 %) despite its disordered microcrystalline structure. However, commercialization of this technology has been limited by structural and chemical variations in CIGS films. Many microscopic and spectroscopic studies have shown built-in electric potentials (Φbi) at CIGS grain boundaries. This may assist with electron-hole separation, but the reported magnitude and statistical distribution of Φbi remains inconsistent between studies. In this work, photoemission and low-energy electron microscopies (PEEM and LEEM) were used to reconcile these reported differences. Highly surface sensitive PEEM measurements showed Φbi ~ 0 . 5 V, which was consistent with most other reports. However, more bulk sensitive LEEM measurements showed Φbi ~ 1 . 5 V, which strongly suggests p- to n-type inversion at CIGS grain boundaries. This formation of pn junctions at CIGS grain boundaries is likely responsible for the high performance of CIGS photovoltaics. Sandia is managed by Sandia Corp., a subsidiary of Lockheed Martin, for the U.S. DOE NNSA (DE-AC04-94AL85000). Work was supported by an U.S. DOE EERE SunShot Bridging Research Interactions through collaborative Development Grants in Energy (BRIDGE).

  3. CuIn{sub 1-x}Ga{sub x}Se{sub 2}-based solar cells prepared from low-cost precursors

    Energy Technology Data Exchange (ETDEWEB)

    Calixto, M.E; Sebastian, P. J; M, Pattabi; Mathew, X; McClure, J. C [CIE-UNAM, Temixco, Morelos (Mexico)

    2000-07-01

    We report the characterization results obtained for the one step electrodeposited CuInSe{sub 2} (CIS) thin films and photovoltaic structures based on CIS and CuIn{sub 1-x}Ga{sub x}Se{sub 2} (CIGS). CIS thin films were deposited on Mo coated glass substrates, varying the deposition conditions. During the initial stages of deposition process the chemical concentration of the CIS films is rich in Cu an Se. But, after a few minutes, the concentration profile becomes constant through out the rest of the deposition process and at the end of the deposition process the film becomes In rich. The samples were analyzed using the ICP (Inductive Coupled Plasma), EDAX (Energy Dispersive Analysis by X-rays), AES (Auger Electron Spectroscopy), XRD (X-Ray Diffraction) and SEM (Scanning Electron Microscopy) techniques. The photovoltaic structures based on electrodeposited CIS and CIGS did the solar conversion with efficiency of the order of 10%. [Spanish] Informamos sobre los resultados de caracterizacion obtenidos de electrodeposicion en un solo paso de peliculas delgadas de CuInSe{sub 2} (CIS) y estructuras fotovoltaicas basadas en CIS y CuInxGal-xSe2(CIGS). Las peliculas delgadas de CIS se depositaron sobre substratos de vidrio recubiertos de Mo, variando las condiciones de deposicion. Durante las etapas iniciales del proceso de deposicion la concentracion de las peliculas de CIS es rica en Cu y Se pero despues de unos cuantos minutos el perfil de concentracion se vuelve constante a durante todo el resto de proceso de deposicion y al final del proceso de deposicion la pelicula se convierte rica en In. Las muestras se analizaron ICP (plasma acoplado inductivo) EDAX (analisis de dispersion de energia por rayos X) AES (espectroscopia electronica Auger) XRD (difraccion de rayos X) y SEM (microscopia de barrido electronico). Las estructuras fotovoltaicas basados en CIS electrodepositado y CIGS hicieron la conversion solar con eficiencias de alrededor del 10%.

  4. Incorporation of Cu in Cu(In,Ga)Se{sub 2}-based thin-film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Yong-Duck; Cho, Dae-Hyung; Han, Won-Seok; Park, Nae-Man; Lee, Kyu-Seok; Kim, Je-Ha [Electronics and Telecommunications Research Institute, Daejeon (Korea, Republic of)

    2010-12-15

    We have fabricated Cu(In,Ga)Se{sub 2} (CIGS)-based thin-film solar cells by using a cluster-type deposition system. The system is composed of a DC sputter for the Mo back electrode, a co-evaporator for the CIGS absorption layer, and a RF sputter for the ZnO and the transparent-conductive-oxide (TCO) window layers. The deposition of the CdS buffer layer was performed separately. Two solar cells with an effective area of 0.47 cm{sup 2} were fabricated using different processes. One cell, which was prepared with a 1-step process, had a larger atomic concentration of In-Ga than of Cu in the absorption layer and showed a conversion efficiency of 11.1%. The other prepared with a 3-step process had nearly the same In-Ga and Cu concentrations and showed a conversion efficiency of 15.5%. We discuss the incorporation of Cu in the two types of thin-film solar cells.

  5. ZnMgO by APCVD Enabling High-Performance Mid-bandgap CIGS on Polyimide Modules: October 2009--October 2010

    Energy Technology Data Exchange (ETDEWEB)

    Woods, L.

    2011-04-01

    This Pre-Incubator project was designed to increase the 'real world' CIGS based photovoltaic module performance and decrease the Levelized Cost of Energy (LCOE) of systems utilizing those modules compared to our traditional CIGS based photovoltaic modules. This was enabled by a) increasing the CIGS bandgap and b) developing better matched device finishing layers to the mid-bandgap CIGS based photovoltaics; including window and buffer layers (and eventually the TCO). Incremental progress in the novel device performance was demonstrated throughout the program, and ultimately achieved performance results that exceeded the milestones ahead of schedule. Metal-oxide buffer layer devices with mid-bandgap CIGS alloys on polyimide substrates were produced with efficiencies of over 12%. Corresponding mid-bandgap devices with CdS buffers produced over 13% efficient devices. Furthermore, no obvious degradation in the device performance has been observed to date, after proper storage ambient of the different types of unencapsulated devices were identified.

  6. 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

  7. Device Physics of Nanoscale Interdigitated Solar Cells (Poster)

    Energy Technology Data Exchange (ETDEWEB)

    Metzger, W.; Levi, D.

    2008-05-01

    Nanoscale interdigitated solar cell device architectures are being investigated for organic and inorganic solar cell devices. Due to the inherent complexity of these device designs quantitative modeling is needed to understand the device physics. Theoretical concepts have been proposed that nanodomains of different phases may form in polycrystalline CIGS solar cells. These theories propose that the nanodomains may form complex 3D intertwined p-n networks that enhance device performance.Recent experimental evidence offers some support for the existence of nanodomains in CIGS thin films. This study utilizes CIGS solar cells to examine general and CIGS-specific concepts in nanoscale interdigitated solar cells.

  8. 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.

  9. Microstructural evolution of all-wet-processed CIGS films using Raman spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hee Soo; Choi, Eunmi; Kim, Areum; Pyo, Sung Gyu [School of Integrative Engineering, Chung-Ang University, 221 Heukseok-Dong, Seoul, 156-756 (Korea, Republic of); Yoon, Sung Pil [Fuel Cell Research Center, Korea Institute of Science and Technology, Seoul, 136-791 (Korea, Republic of)

    2014-08-15

    We report a wet process deposition in order to identify a cost-effective processing scheme for CuIn{sub 1-x}Ga{sub x}Se{sub 2} (CIGS) layers on molybdenum/soda lime glass substrates from a Cu-In-Ga precursor solution. We employed a spin coater at various settings to evaluate the uniformity of the resulting CIGS solar cell layer. After the CIGS precursor film was deposited, we applied a selenization process. In the selenization process, we used a controlled temperature RTA system and compared it to a noncontrolled temperature system. We investigated the morphological properties for different selenization temperature treatments. We used Raman mapping to detect binary compounds and found the binary compound effect on the film. Raman mapping results show that the density of the binary compound in the CIGS layer increased with selenization temperature, and at 600 C, the density of the binary compounds was highest. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. 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.

  11. CIGS P3 scribes using ultra-short laser pulses and thermal annealing

    Science.gov (United States)

    Matthäus, Gabor; Bergner, Klaus; Ametowobla, Mawuli A.; Letsch, Andreas; Tünnermann, Andreas; Nolte, Stefan

    2016-03-01

    Thin-film photovoltaic panels consist of individual solar cells which are monolithically interconnected in series. Today, these connections are commonly realized by mechanical methods. In order to increase the solar output, it is one approach to minimize the interconnection area (so called "dead area"). In this regard, recent advances in laser patterning are gaining increasing potential. However, especially high-impedance trenches realized via laser scribing generally suffer from insufficient shunt resistances. This is especially the case for the third structuring stage P3 of CIGS solar modules, which represents the isolation of nearby cells.

  12. Nanoscale Measurements of the Surface Photovoltage in Cu(In,Ga)Se2, Cu2ZnSn4, and Cu2ZnSnSe4 Thin Films: The Role of the Surface Electronics on the Efficiency of Solar Cells: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Du, H.; Romero, M. J.; Repins, I.; Teeter, G.; Noufi, R.; Al-Jassim, M. M.

    2011-07-01

    We report on recent advances in the development of nanoscale measurements of the surface photovoltage (SPV) based on scanning tunneling microscopy (STM) and its application to the kesterites Cu2ZnSnS4 (CZTS) and Cu2ZnSnSe4 (CZTSe). One critical aspect of the electronic structure of Cu(In,Ga)Se2 (CIGS) that has yet to be determined in their related kesterite compounds is the character of the surface electronics. In CIGS, spontaneous deviations in the stoichiometry of the surface cause a depletion (or even a type inversion) region that reinforces the CIGS homojunction. First-principle calculations predict that this inversion region will be more difficult to form in CZTS. In this contribution, the characteristics of the surface space charge region for both CIGS and CZTS(e) are investigated by STM. The implications of the results of these measurements on the future development of CZTS solar cells will be discussed.

  13. Buffer layer selection for CuIn1 - x Ga x Se2 based thin film solar cells

    Science.gov (United States)

    Kumari, Sarita; Singh Verma, Ajay

    2014-03-01

    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.

  14. Solar Panel based Milk Pasteurization

    DEFF Research Database (Denmark)

    Nielsen, Kirsten Mølgaard; Pedersen, Tom Søndergaard

    This paper treats the subject of analysis, design and development of the control system for a solar panel based milk pasteurization system to be used in small villages in Tanzania. The analysis deals with the demands for an acceptable pasteurization, the varying energy supply and the low cost, low...... system is dimensioned. A functional prototype of the pasteurization facility with a capacity of 200 l milk/hour has been developed and tested. The system is prepared for solar panels as the main energy source and is ready for a test in Tanzania....

  15. Solar Panel based Milk Pasteurization

    DEFF Research Database (Denmark)

    Nielsen, Kirsten Mølgaard; Pedersen, Tom Søndergaard

    2002-01-01

    This paper treats the subject of analysis, design and development of the control system for a solar panel based milk pasteurization system to be used in small villages in Tanzania. The analysis deals with the demands for an acceptable pasteurization, the varying energy supply and the low cost, low...... system is dimensioned. A functional prototype of the pasteurization facility with a capacity of 200 l milk/hour has been developed and tested. The system is prepared for solar panels as the main energy source and is ready for a test in Tanzania....

  16. 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.

  17. Modeling of Thin Film Solar Photovoltaic Based on Zno/Sns Oxide-Absorber Substrate Configuration

    Directory of Open Access Journals (Sweden)

    Anupam Verma

    2014-06-01

    Full Text Available Due to increasing awareness for using clean energy and therefore greater demand for relying more on the renewable sources which solar photovoltaic are part of because they pose very little or no threat to the environment comparatively, there is growing pressure for reducing electricity generation costs from solar photovoltaic (PV modules. Hence there is need for alternative new light absorbing materials that can provide conversion efficiencies which would be comparable to the current technologies based on crystalline silicon and CdTe or CIGS thin films at lower manufacturing costs and therefore providing cost effective solutions. In this paper we have evaluated the tin based absorber material (based on tin monosulfide; SnS as the next generation of Photovoltaic cells that can provide the desired performance in the long term. Therefore it explores the potential use of tin mono-sulfide as photovoltaic material for conversion of light into electricity. Zinc Oxide (ZnO thin films have been recognized as good candidates in photovoltaic devices acting as wide-band gap window layer. The results are presented through the numerical analysis done by AMPD-1D simulator tool to explore the possibility of using thin film and stable ZnO/SnS solar photovoltaic device with aim to achieve comparable conversion efficiencies.

  18. Progress in Polycrystalline Thin-Film Cu(In,GaSe2 Solar Cells

    Directory of Open Access Journals (Sweden)

    Udai P. Singh

    2010-01-01

    Full Text Available For some time, the chalcopyrite semiconductor CuInSe2 and its alloy with Ga and/or S [Cu(InGaSe2 or Cu(InGa(Se,S2], commonly referred as CIGS, have been leading thin-film material candidates for incorporation in high-efficiency photovoltaic devices. CuInSe2-based solar cells have shown long-term stability and the highest conversion efficiencies among all thin-film solar cells, reaching 20%. A variety of methods have been reported to prepare CIGS thin film. Efficiency of solar cells depends upon the various deposition methods as they control optoelectronic properties of the layers and interfaces. CIGS thin film grown on glass or flexible (metal foil, polyimide substrates require p-type absorber layers of optimum optoelectronic properties and n-type wideband gap partner layers to form the p-n junction. Transparent conducting oxide and specific metal layers are used for front and back contacts. Progress made in the field of CIGS solar cell in recent years has been reviewed.

  19. 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.

  20. 7 CFR 1466.27 - Conservation Innovation Grants (CIG).

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Conservation Innovation Grants (CIG). 1466.27 Section... PROGRAM Contracts and Payments § 1466.27 Conservation Innovation Grants (CIG). (a) Definitions. In.... (3) Grant Review Board consists of the NRCS Deputy Chief for Programs, Deputy Chief for Science...

  1. Dynamics of the isolated galaxy CIG 0314

    CERN Document Server

    Verley, S; Repetto, P; Gabbasov, R; Verdes-Montenegro, L; Bergond, G; Fuentes-Carrera, I; Durbala, A

    2009-01-01

    In the context of the AMIGA project, we used Fabry-Perot observations in order to study the dynamics of the ionised gas in the isolated galaxy CIG 0314. From the Halpha observations, we could obtain the velocity field and rotation curve of the galaxy. A detail analysis of the velocity field is done in order to understand the kinematics of the gas to gather clues on the mechanisms which favour or inhibit star formation, in particular along the bar. The visible and dark matter content can be reached, as well as an estimation of the mass of the galaxy.

  2. Solar based hydrogen production systems

    CERN Document Server

    Dincer, Ibrahim

    2013-01-01

    This book provides a comprehensive analysis of various solar based hydrogen production systems. The book covers first-law (energy based) and second-law (exergy based) efficiencies and provides a comprehensive understanding of their implications. It will help minimize the widespread misuse of efficiencies among students and researchers in energy field by using an intuitive and unified approach for defining efficiencies. The book gives a clear understanding of the sustainability and environmental impact analysis of the above systems. The book will be particularly useful for a clear understanding

  3. 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

  4. Filmes calcogenetos para células solares: crescimento e propriedades

    OpenAIRE

    Salomé, Pedro Manuel Parracho

    2011-01-01

    Thin film solar cells have in recent years gained market quota against traditional silicon photovoltaic panels. These developments were in a large part due to CdTe solar panels on whose development started earlier than their competitors. Panels based on Cu(In,Ga)Se2 (CIGS), despite being more efficient in a laboratory and industrial scale than the CdTe ones, still need a growth technology cheaper and easier to apply in industry. Although usually presented as a good candidate...

  5. Layer-by-Layer Nanoassembly of Copper Indium Gallium Selenium Nanoparticle Films for Solar Cell Applications

    Directory of Open Access Journals (Sweden)

    A. Hemati

    2012-01-01

    Full Text Available Thin films of CIGS nanoparticles interdigited with polymers have been fabricated through a cost-effective nonvacuum film deposition process called layer-by-layer (LbL nanoassembly. CIGS nanoparticles synthesized by heating copper chloride, indium chloride, gallium chloride, and selenium in oleylamine were dispersed in water, and desired surface charges were obtained through pH regulation and by coating the particles with polystyrene sulfonate (PSS. Raising the pH of the nanoparticle dispersion reduced the zeta-potential from +61 mV at pH 7 to −51 mV at pH 10.5. Coating the CIGS nanoparticles with PSS (CIGS-PSS produced a stable dispersion in water with −56.9 mV zeta-potential. Thin films of oppositely charged CIGS nanoparticles (CIGS/CIGS, CIGS nanoparticles and PSS (CIGS/PSS, and PSS-coated CIGS nanoparticles and polyethylenimine (CIGS-PSS/PEI were constructed through the LbL nanoassembly. Film thickness and resistivity of each bilayer of the films were measured, and photoelectric properties of the films were studied for solar cell applications. Solar cell devices fabricated with a 219 nm CIGS film, when illuminated by 50 W light-source, produced 0.7 V open circuit voltage and 0.3 mA/cm2 short circuit current density.

  6. Highly reflective rear surface passivation design for ultra-thin Cu(In,Ga) Se-2 solar cells

    OpenAIRE

    Vermang, Bart; Timo Watjen, Jorn; Fjallstrom, Viktor; Rostvall, Fredrik; Edoff, Marika; Gunnarsson, Rickard; Pilch, Iris; Helmersson, Ulf; Kotipalli, Ratan; Henry, Frederic; Flandre, Denis

    2015-01-01

    Al2O3 rear surface passivated ultra-thin Cu(In,Ga)Se-2 (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 w...

  7. Degradation of Cu(In, Ga)Se{sub 2} thin-film solar cells due to the ionization effect of low-energy electrons

    Energy Technology Data Exchange (ETDEWEB)

    Kawakita, Shirou, E-mail: kawakita.shirou@jaxa.jp [Japan Aerospace Exploration Agency (JAXA), Tsukuba, Ibaraki 305-8505 (Japan); Imaizumi, Mitsuru [Japan Aerospace Exploration Agency (JAXA), Tsukuba, Ibaraki 305-8505 (Japan); Ishizuka, Shogo; Shibata, Hajime; Niki, Shigeru [National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan); Okuda, Shuichi [Osaka Prefecture University (OPU), Sakai, Osaka 599-8570 (Japan); Kusawake, Hiroaki [Japan Aerospace Exploration Agency (JAXA), Tsukuba, Ibaraki 305-8505 (Japan)

    2015-05-01

    Cu (In, Ga)Se{sub 2} (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 III{sub Cu} 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 III{sub Cu} 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.

  8. 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.

  9. Soft X-ray absorption spectroscopy investigation of the surface chemistry and treatments of copper indium gallium diselenide (CIGS)

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, Craig; Nordlund, Dennis; Sokaras, Dimosthenis; Contreras, Miguel; Weng, Tsu-Chien; Mansfield, Lorelle; Hurst, Katherine E.; Dameron, Arrelaine; Ramanathan, Kannan; Prendergast, David; Christensen, Steven T.

    2017-02-01

    The surface and near surface structure of copper-indium-gallium-selenide (CIGS) absorber layers is integral to the producing a high-quality photovoltaic junction. By using X-ray absorption spectroscopy (XAS) and monitoring multiple elemental absorption edges with both theory and experiment, we are able to identify several features of the surface of CIGS as a function of composition and surface treatments. The XAS data shows trends in the near surface region of oxygen, copper, indium and gallium species as the copper content is varied in the films. The oxygen surface species are also monitored through a series of experiments that systematically investigates the effects of water and various solutions of: ammonium hydroxide, cadmium sulfate, and thiourea. These being components of cadmium sulfide chemical bath deposition (CBD). Characteristics of the CBD are correlated with a restorative effect that produces as normalized, uniform surface chemistry as measured by XAS. This surface chemistry is found in CIGS solar cells with excellent power conversion efficiency (<19%). The results provide new insight for CIGS processing strategies that seek to replace CBD and/or cadmium sulfide.

  10. 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.

  11. 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.

  12. 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

    NARCIS (Netherlands)

    Burghoorn, M.M.A.; Kniknie, B.J.; Deelen, J. van; Xu, M.; Vroon, Z.A.E.P.; Ee, R.J. van; Belt, R. van de; Buskens, P.J.P.

    2014-01-01

    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

  13. E-Cigs May Be 'Bridge' to Teens' Tobacco Use

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_163491.html E-Cigs May Be 'Bridge' to Teens' Tobacco Use ' ... 8, 2017 (HealthDay News) -- Nonsmoking teens who use e-cigarettes appear to be more likely to light ...

  14. 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.

  15. Vaping cannabis (marijuana): parallel concerns to e-cigs?

    OpenAIRE

    Budney, Alan J.; Sargent, James D.; Lee, Dustin C.

    2015-01-01

    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 benefit...

  16. 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.

  17. 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

    OpenAIRE

    M. Burghoorn; B. Kniknie; Deelen, J; Xu., M; Z. Vroon; van Ee, R.; van de Belt, R.; Buskens, P

    2014-01-01

    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 transp...

  18. Web based Measurement System for Solar Radiation

    Directory of Open Access Journals (Sweden)

    Shachi Awasthi

    2012-06-01

    Full Text Available We present in this paper, the principles of the measurement system for solar radiation, and our implementation using Web based data logging concept. The photocurrent produced by Silicon PN junction is used as a solar radiation transducer, to make it more viable we have used commercially available solar panels as our transducers. Using a silicon solar cell as sensor, a low cost solar radiometer can be constructed. The photocurrent produced by solar cell is electronically tailored to be measured and stored by our web based data acquisition and monitoring system. Measurement using real solar cell array gives a good measure of actual producible energy by solar arrays. Our portable instrument can be used in remote sites and substitutes the solar monitor and integrator, Current data of solar radiation can be monitored using Ethernet interface available in all PC, Laptops. We store the data into a secure digital card which can be retrieved to plot and analyse the data. We have developed system hardware and software based on ATmega32 AVR Microcontrollers and ENC28J60 Ethernet PHY and MAC network interface chip by Microchip. So the global irradiance data are obtained after correction using the instantaneous measurement of ambient temperature which allows us to calculate the junction temperature and consequently improve the precision of measurement of our data acquisition system.

  19. Theoretical comparison between solar combisystems based on bikini tanks and tank-in-tank solar combisystems

    DEFF Research Database (Denmark)

    Yazdanshenas, Eshagh; Furbo, Simon; Bales, Chris

    2008-01-01

    Theoretical investigations have shown that solar combisystems based on bikini tanks for low energy houses perform better than solar domestic hot water systems based on mantle tanks. Tank-in-tank solar combisystems are also attractive from a thermal performance point of view. In this paper......, theoretical comparisons between solar combisystems based on bikini tanks and tank-in-tank solar combisystems are presented....

  20. Investigations on electron beam evaporated Cu(In{sub 0.85}Ga{sub 0.15})Se{sub 2} thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Venkatachalam, M.; Kannan, M.D.; Prasanna, S.; Jayakumar, S.; Balasundaraprabhu, R. [Thin Film Center, Department of Physics, PSG College of Technology, Coimbatore (India); Muthukumarasamy, N. [Department of Physics, Coimbatore Institute of Technology, Coimbatore (India); Saroja, M. [Department of Electronics, Erode Arts College, Erode (India)

    2009-09-15

    CIGS bulk with composition of CuIn{sub 0.85}Ga{sub 0.15}Se{sub 2} was synthesized by direct reaction of elemental copper, indium, gallium and selenium. CIGS thin films were then deposited onto well-cleaned glass substrates using the prepared bulk alloy by electron beam deposition method. The structural properties of the deposited films were studied using X-ray diffraction technique. The as-deposited CIGS films were found to be amorphous. On annealing, the films crystallized with a tetragonal chalcopyrite structure. An intermediate Cu-rich phase precipitated at 200 C and dissociated at higher annealing temperatures. Average grain size calculated from the XRD spectra indicated that the films had a nano-crystalline structure and was further corroborated by AFM analysis of the sample surface. The chemical constituents present in the deposited CIGS films were identified using energy dispersive X-ray analysis. CIGS based solar cells were then fabricated on molybdenum and ITO coated glass substrates and the efficiencies have been evaluated. (author)

  1. Web based Measurement System for Solar Radiation

    Directory of Open Access Journals (Sweden)

    Shachi Awasthi

    2012-06-01

    Full Text Available We present in this paper, the principles of themeasurement system for solar radiation, and ourimplementation using Web based data loggingconcept.The photocurrent produced by Silicon PNjunction is used as a solar radiation transducer, tomake it more viable we have used commerciallyavailable solar panels as our transducers. Using asilicon solar cell as sensor, a low cost solarradiometer can be constructed. The photocurrentproduced by solar cell is electronically tailored to bemeasured and stored by our web based dataacquisition and monitoring system. Measurementusing real solar cell array gives a good measure ofactual producible energy by solar arrays. Ourportable instrument can be used in remote sites andsubstitutes the solar monitor and integrator,Current data of solar radiation can be monitoredusing Ethernet interface available in all PC,Laptops. We store the data into a secure digital cardwhich can be retrieved to plot and analyse the data.We have developed system hardware andsoftware based on ATmega32 AVR Microcontrollersand ENC28J60 Ethernet PHY and MAC networkinterface chip by Microchip.So the global irradiance data are obtained aftercorrection using the instantaneous measurement ofambient temperature which allows us to calculatethe junction temperature and consequently improvethe precision of measurement of our dataacquisition system

  2. Effects of selenization conditions on densification of Cu(In,Ga)Se2 (CIGS) thin films prepared by spray deposition of CIGS nanoparticles

    Science.gov (United States)

    Ahn, SeJin; Kim, Ki Hyun; Yun, Jae Ho; Yoon, Kyung Hoon

    2009-06-01

    Spray deposited porous CIGS nanoparticle-derived thin films were selenized in a two zone rapid thermal annealing furnace and effects of various selenization parameters including Se evaporation temperature, flow rate of carrier gas, and substrate temperature on densification of the CIGS layers were investigated. It was found that higher Se supply to CIGS nanoparticles either by increasing Se evaporation temperature or by increasing the flow rate of carrier gas resulted in larger CIGS grains with higher degree of crystallinity, while it also induced formation of a thicker MoSe2 layer in-between CIGS and Mo which resulted in partial detachment of CIGS/MoSe2/Mo layers from the glass substrate. Densification of CIGS layer by growth of nanoparticles and formation of thick MoSe2 were explained by a liquid Se assisted reaction rather than by a vapor phase Se assisted reaction.

  3. Aspects of designing an optimized molybdenum back contact in CIGS-technology

    Energy Technology Data Exchange (ETDEWEB)

    Oertel, Michael; Goetz, Stefan; Haarstrich, Jakob; Metzner, Heinrich; Reisloehner, Udo; Ronning, Carsten; Wesch, Werner [Institut fuer Festkoerperphysik, Friedrich-Schiller-Universitaet Jena, 07743 Jena (Germany)

    2011-07-01

    In Cu(In,Ga)Se{sub 2}(CIGS)-solar cell and module production, the sputtering of the molybdenum back contact is the first step in nearly all process lines. We present our results of experiments to elucidate the different aspects which have to be kept in mind when depositing the molybdenum back contact by dc-magnetron sputtering. These aspects include: I) The adhesion of the molybdenum to the glass substrate as well as the adhesion of the CIGS-layer to the molybdenum, II) electrical conductivity, III) sodium diffusion and IV) the specific contact resistance of the molybdenum to the aluminium doped zinc oxide (Al:ZnO) window layer. We present our three layer design of the back contact which combines an optimized adhesion to both the substrate and the absorber and also a high electrical conductivity. X-ray diffraction measurements (XRD) are employed to characterize each single layer. We also discuss I-U-measurements of CuInSe{sub 2}-solar cells made in a sequential absorber layer process in order to study the sodium transport behaviour of molybdenum back contacts sputtered at different argon sputter pressures. The sodium content in the absorber and the different back contact layers is measured by secondary ion mass spectroscopy (SIMS). A lowest value of the specific contact resistance between the Mo and the Al:ZnO of (1.37{+-}0.14).10{sup 5} {omega}cm{sup 2} was determined.

  4. Multilayer Transparent Top Electrode for Solution Processed Perovskite/Cu(In,Ga)(Se,S)2 Four Terminal Tandem Solar Cells.

    Science.gov (United States)

    Yang, Yang Michael; Chen, Qi; Hsieh, Yao-Tsung; Song, Tze-Bin; Marco, Nicholas De; Zhou, Huanping; Yang, Yang

    2015-07-28

    Halide perovskites (PVSK) have attracted much attention in recent years due to their high potential as a next generation solar cell material. To further improve perovskites progress toward a state-of-the-art technology, it is desirable to create a tandem structure in which perovskite may be stacked with a current prevailing solar cell such as silicon (Si) or Cu(In,Ga)(Se,S)2 (CIGS). The transparent top electrode is one of the key components as well as challenges to realize such tandem structure. Herein, we develop a multilayer transparent top electrode for perovskite photovoltaic devices delivering an 11.5% efficiency in top illumination mode. The transparent electrode is based on a dielectric/metal/dielectric structure, featuring an ultrathin gold seeded silver layer. A four terminal tandem solar cell employing solution processed CIGS and perovskite cells is also demonstrated with over 15% efficiency.

  5. 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.

  6. Design and realization of transparent solar modules based on luminescent solar concentrators integrating nanostructured photonic crystals

    Science.gov (United States)

    Jiménez‐Solano, Alberto; Delgado‐Sánchez, José‐Maria; Calvo, Mauricio E.; Miranda‐Muñoz, José M.; Lozano, Gabriel; Sancho, Diego; Sánchez‐Cortezón, Emilio

    2015-01-01

    Abstract Herein, we present a prototype of a photovoltaic module that combines a luminescent solar concentrator integrating one‐dimensional photonic crystals and in‐plane CuInGaSe2 (CIGS) solar cells. Highly uniform and wide‐area nanostructured multilayers with photonic crystal properties were deposited by a cost‐efficient and scalable liquid processing amenable to large‐scale fabrication. Their role is to both maximize light absorption in the targeted spectral range, determined by the fluorophore employed, and minimize losses caused by emission at angles within the escape cone of the planar concentrator. From a structural perspective, the porous nature of the layers facilitates the integration with the thermoplastic polymers typically used to encapsulate and seal these modules. Judicious design of the module geometry, as well as of the optical properties of the dielectric mirrors employed, allows optimizing light guiding and hence photovoltaic performance while preserving a great deal of transparency. Optimized in‐plane designs like the one herein proposed are of relevance for building integrated photovoltaics, as ease of fabrication, long‐term stability and improved performance are simultaneously achieved. © 2015 The Authors. Progress in Photovoltaics: Research and Applications published by John Wiley & Sons Ltd. PMID:27656090

  7. 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.

  8. 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.

  9. Impact of P2 scribe geometry on monolithic series interconnected CIGS modules

    Science.gov (United States)

    Rekow, M.; Bartl, D.; Sandfort, C.; Letsch, A.

    2013-03-01

    The CIGS (Copper Indium Gallium Selenide) solar panel industry is cautiously moving to adopt laser processes for the P2 and the P3 scribe steps that form the electrical interconnection between cells within a module [1]. In this work we study variants of these two laser processes and evaluate their relative performance. P2 scribes are applied with geometries that range from continuous scribes to discrete spots and we examine the relationship between scribe geometry and P2 contact resistance. Transmission line theory [2] is used to calculate P2 contact resistance as is common in the industry. The results are compared with two simple geometric models that predict relative contact resistance for different scribe geometries. We also apply different types of scribes for both P2 and P3 in the production of minimodules and evaluate the results. We find that not only is the optimal geometry for the P2 scribe a continuous line, high overlap of the laser spots yields an improvement in contact resistance not predicted by geometry alone. Finally we find that removing only the TCO (transparent conductive oxide) layer for the P3 scribe results in modules with good efficiency, however a P3 scribe that removes the TCO and CIGS layer yields better modules with about 1% higher absolute efficiency.

  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. 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.

  12. 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

  13. Electronic level alignment at the deeply buried absorber/Mo interface in chalcopyrite-based thin film solar cells

    Science.gov (United States)

    Bär, M.; Nishiwaki, S.; Weinhardt, L.; Pookpanratana, S.; Shafarman, W. N.; Heske, C.

    2008-07-01

    We have investigated the electronic structure of the absorber/back contact interface for S-free [Cu(In ,Ga)Se2 ("CIGSe")] and S-containing [Cu(In ,Ga)(S,Se)2 ("CIGSSe")] chalcopyrites with direct and inverse photoemission. Comparison of the electronic levels of the cleavage planes reveals a pronounced cliff in the conduction band at the CIG(S )Se/Mo interface. For the valence band, we find a flat alignment and a small spike for the CIGSe- and CIGSSe-based structures, respectively.

  14. 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

  15. Highly reflective rear surface passivation design for ultra-thin Cu(In,Ga)Se{sub 2} solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Vermang, Bart, E-mail: Bart.Vermang@angstrom.uu.se [Ångström Solar Center, University of Uppsala, Uppsala 75121 (Sweden); ESAT-KU Leuven, University of Leuven, Leuven 3001 (Belgium); Wätjen, Jörn Timo; Fjällström, Viktor; Rostvall, Fredrik; Edoff, Marika [Ångström Solar Center, University of Uppsala, Uppsala 75121 (Sweden); Gunnarsson, Rickard; Pilch, Iris; Helmersson, Ulf [Plasma & Coatings Physics, University of Linköping, Linköping 58183 (Sweden); Kotipalli, Ratan; Henry, Frederic; Flandre, Denis [ICTEAM/IMNC, Université Catholique de Louvain, Louvain-la-Neuve 1348 (Belgium)

    2015-05-01

    Al{sub 2}O{sub 3} rear surface passivated ultra-thin Cu(In,Ga)Se{sub 2} (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 Al{sub 2}O{sub 3} 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/cm{sup 2}; 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 Al{sub 2}O{sub 3} film passivates the CIGS rear surface between these nano-particles. • [Ga]/([Ga] + [In]) grading is used to reduce Mo-NP/CIGS interface recombination.

  16. New processing approaches for Cu2ZnSnSe4-based solar cells

    OpenAIRE

    López Mariño, Simón

    2016-01-01

    The present thesis focuses on the promising semiconductor material kesterite, Cu2ZnSn(S,Se)4, known as CZTS(e), which is used in the second generation of solar cells, generally known as thin film photovoltaics (PV). This material relies on earth-abundant, low-cost and low toxic elements which certainly attract the interest of both research community and industry. Kesterite could replace its well known and already commercialised thin film counterpart, CuIn(1-x)Gax(SySe1-y)2 (CIGS), since it ha...

  17. Current trends in ground based solar magnetometry

    Science.gov (United States)

    Gosain, Sanjay

    2016-07-01

    Continuous observations of the sun, over more than a century, have led to several important discoveries in solar astronomy. These include the discovery of the solar magnetism and its cyclic modulation, active region formation and decay and their role in energetic phenomena such as fares and coronal mass ejections (CMEs), fine structure and dynamics of the sunspots and small-scale organization of the magnetic flux in the form of flux tubes and so forth. In this article we give a brief overview of advancements in solar observational techniques in recent decades and the results obtained from the such observations. These include techniques to achieve high angular resolution, high spectral and polarimetric sensitivity and innovative new detectors. A wide range of spatial, temporal and spectral domains exploited by solar astronomers to understand the solar phenomena are discussed. Many new upcoming telescopes and instruments that are designed to address different aspects of solar physics problems are briefly described. Finally, we discuss the advantages of observing from the ground and how they can complement space-based observations.

  18. PIC BASED SOLAR CHARGING CONTROLLER FOR BATTERY

    Directory of Open Access Journals (Sweden)

    Mrs Jaya N. Ingole

    2012-02-01

    Full Text Available Solar resource is unlimited the government is trying to implement the use of Solar panels as an energy source in rural and sub urban areas for lighting the street lights, but the battery used to store the power gets affected due to overcharge & discharges. This paper presents the use of PIC16F72 based solar charger controller for controlling the overcharging and discharging of a solar cell. It works by continuously optimizing the interface between the solar array and battery. First, the variable supply is fixed at 12.8V dc—the voltage of a fully charged battery— and linked to the battery point of the circuit. Cut Off of battery from load voltage is 10.8 volt. A PIC16F72 for small size and inbuilt analog inputs is used to determine voltage level of battery and solar panel..It also describes how the disadvantages of analog circuit are overcome by this controller. The flow chart is also provided.

  19. 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)

  20. Enhancing the light absorbance of polymer solar cells by introducing pulsed laser-deposited CuIn0.8Ga0.2Se2 nanoparticles

    OpenAIRE

    Zhao, Yu; LI, Hui; Liu, Xu-Jun; Guan, Lei-Lei; Li, Yan-Li; Sun, Jian; Ying, Zhi-Feng; Wu, Jia-Da; Xu,Ning

    2014-01-01

    Evenly separated crystalline CuIn0.8Ga0.2Se2 (CIGS) nanoparticles are deposited on ITO-glass substrate by pulsed laser deposition. Such CIGS layers are introduced between conjugated polymer layers and ITO-glass substrates for enhancing light absorbance of polymer solar cells. The P3HT:PCBM absorbance between 300 and 650 nm is enhanced obviously due to the introduction of CIGS nanoparticles. The current density-voltage curves of a P3HT:PCBM/CIGS solar cell demonstrate that the short-circuit cu...

  1. 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

  2. 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.

  3. 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).

  4. Substrate temperature optimization for Cu(In, Ga)Se{sub 2} solar cells on flexible stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Liang, X.; Zhu, H.; Chen, J., E-mail: chenjingwei@126.com; Zhou, D.; Zhang, C.; Guo, Y.; Niu, X.; Li, Z.; Mai, Y., E-mail: yaohuamai@hbu.edu.cn

    2016-04-15

    Graphical abstract: - Highlights: • CIGS thin films are deposited on flexible SS substrates at different substrate temperatures. • CIGS thin films deposited at different T{sub S2} show different Ga/(Ga + In) ratio profiles. • All CIGS thin films show (112) and (220/204) preferred orientations with a shift to higher angles. • Conversion efficiency of 11.3% is obtained for CIGS solar cells deposited at 500 °C. - Abstract: Cu(In, Ga)Se{sub 2} (CIGS) thin films are deposited on flexible stainless steel (SS) substrates using the so called 3-stage co-evaporation process at different substrate temperatures ranging from 440 °C to 640 °C during the 2nd stage and the 3rd stage (T{sub S2}). The effects of T{sub S2} on the properties of CIGS thin films are systematically investigated. It is found by secondary ion mass spectrometry measurement that CIGS thin films deposited at different T{sub S2} show different Ga/(Ga + In) ratio (GGI) profiles along the growth direction. High T{sub S2} facilitates the grain growth and leads to larger grain size. However, high T{sub S2} worsens the spectral response of CIGS solar cells in the long wavelength range, which is partly attributed to the too much iron atom diffusion from the SS substrates into the CIGS thin films. All CIGS thin films show (112) preferred orientations with a shift to higher angle due to variation of compositions. A shoulder-like two-peak structure of (112) and (220/204) peaks appears for CIGS thin films deposited at lower T{sub S2}. Conversion efficiency of 11.3% is obtained for CIGS thin film solar cells deposited at the T{sub S2} of 500 °C.

  5. 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.

  6. Space-Based Solar Power System Architecture

    Science.gov (United States)

    2012-12-01

    and the efficiencies reached by those high volumes is game -changing. By lowering the cost to orbit so substantially, and by providing safe and routine...chosen the same operational orbit for their notional space based solar power satellite. However, due to the prohibitive costs, a pathfinder or...that orbit will minimize the number of launches required to put the satellite into orbit while still allowing a pathfinder satellite to prove

  7. Field modulation in Na-incorporated Cu(In,Ga)Se2 (CIGS) polycrystalline films influenced by alloy-hardening and pair-annihilation probabilities.

    Science.gov (United States)

    Jeong, Yonkil; Kim, Chae-Woong; Park, Dong-Won; Jung, Seung Chul; Lee, Jongjin; Shim, Hee-Sang

    2011-11-07

    The influence of Na on Cu(In,Ga)Se2 (CIGS) solar cells was investigated. A gradient profile of the Na in the CIGS absorber layer can induce an electric field modulation and significantly strengthen the back surface field effect. This field modulation originates from a grain growth model introduced by a combination of alloy-hardening and pair-annihilation probabilities, wherein the Cu supply and Na diffusion together screen the driving force of the grain boundary motion (GBM) by alloy hardening, which indicates a specific GBM pinning by Cu and Na. The pair annihilation between the ubiquitously evolving GBMs has a coincident probability with the alloy-hardening event.PACS: 88. 40. H-, 81. 10. Aj, 81. 40. Cd.

  8. Research on battery array based on solar power

    Science.gov (United States)

    Li, Junhong

    2017-03-01

    Almost all of the energy of solar power supply system comes from solar energy, which is a kind of pollution-free green energy, using independent photovoltaic system as base station power supply. In this paper, taking the solar power system as the research object, we made MATLAB simulation analysis of the independent solar photovoltaic system battery array. The simulation results showed that the output voltage and the output current of the solar array based on solar power system are affected by the illumination intensity and temperature change. In addition, it also showed that at any temperature and illumination intensity, there will a largest output power.

  9. Comparison of Artificial Neural Networks and GIS Based Solar Analysis for Solar Potential Estimation

    Science.gov (United States)

    Konakoǧlu, Berkant; Usta, Ziya; Cömert, Çetin; Gökalp, Ertan

    2016-04-01

    Nowadays, estimation of solar potential plays an important role in planning process for sustainable cities. The use of solar panels, which produces electricity directly from the sun, has become popular in accordance with developing technologies. Since the use of solar panels enables the users to decrease costs and increase yields, the use of solar panels will be more popular in the future. Production of electricity is not convenient for all circumstances. Shading effects, massive clouds and rainy weather are some factors that directly affect the production of electricity from solar energy. Hence, before the installation of solar panels, it is crucial to conduct spatial analysis and estimate the solar potential of the place that the solar panel will be installed. There are several approaches to determine the solar potential. Examination of the applications in the literature reveals that the applications conducted for determining the solar potential are divided into two main categories. Solar potential is estimated either by using artificial neural network approach in which statistical parameters such as the duration of sun shine, number of clear days, solar radiation etc. are used, or by spatial analysis conducted in GIS approaches in which spatial parameters such as, latitude, longitude, slope, aspect etc. are used. In the literature, there are several studies that use both approaches but the literature lacks of a study related to the comparison of these approaches. In this study, Karadeniz Technical University campus has been selected as study area. Monthly average values of the number of clear sky days, air temperature, atmospheric pressure, relative humidity, sunshine duration and solar radiation parameters obtained for the years between 2005 and 2015 will be used to perform artificial neural network analysis to estimate the solar potential of the study area. The solar potential will also be estimated by using GIS-based solar analysis modules. The results of

  10. Study of Emergency Power Based on Solar Battery Charging

    OpenAIRE

    Wang Lei; Zhu Mengfu; Chen Ping; Deng Cheng; Liu Zhimeng; Wang Yanan

    2016-01-01

    To study an emergency power based on solar battery charging. Based on the electric-generation principle of solar panel, solar energy is changed into electrical energy. Through voltage conversion circuit and filter circuit, electrical energy is stored in the energy storage battery. The emergency power realizes the conversion from solar energy to electrical energy. The battery control unit has the function of PWM (Pulse-Width Modulation) charging, overcharging protection, over-discharging prote...

  11. 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.

  12. 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.}

  13. 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.

  14. Fabrication and Characterization of Thin Film Solar Cell Made from CuIn0.75Ga0.25S2 Wurtzite Nanoparticles

    OpenAIRE

    Fengyan Zhang; Chivin Sun; Cyril Bajracharya; Rodriguez, Rene G.; Joshua J. Pak

    2013-01-01

    CuIn0.75Ga0.25S2 (CIGS) thin film solar cells have been successfully fabricated using CIGS Wurtzite phase nanoparticles for the first time. The structure of the cell is Glass/Mo/CIGS/CdS/ZnO/ZnO:Al/Ag. The light absorption layer is made from CIGS Wurtzite phase nanoparticles that are formed from single-source precursors through a microwave irradiation. The Wurtzite phase nanoparticles were converted to Chalcopyrite phase film through a single-step annealing process in the presence of argon an...

  15. Evaluation of solar thermal storage for base load electricity generation

    Science.gov (United States)

    Adinberg, R.

    2012-10-01

    In order to stabilize solar electric power production during the day and prolong the daily operating cycle for several hours in the nighttime, solar thermal power plants have the options of using either or both solar thermal storage and fossil fuel hybridization. The share of solar energy in the annual electricity production capacity of hybrid solar-fossil power plants without energy storage is only about 20%. As it follows from the computer simulations performed for base load electricity demand, a solar annual capacity as high as 70% can be attained by use of a reasonably large thermal storage capacity of 22 full load operating hours. In this study, the overall power system performance is analyzed with emphasis on energy storage characteristics promoting a high level of sustainability for solar termal electricity production. The basic system parameters, including thermal storage capacity, solar collector size, and annual average daily discharge time, are presented and discussed.

  16. 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.

  17. A Space Based Solar Power Satellite System

    Science.gov (United States)

    Engel, J. M.; Polling, D.; Ustamujic, F.; Yaldiz, R.; et al.

    2002-01-01

    (SPoTS) supplying other satellites with energy. SPoTS is due to be commercially viable and operative in 2020. of Technology designed the SPoTS during a full-time design period of six weeks as a third year final project. The team, organized according to the principles of systems engineering, first conducted a literature study on space wireless energy transfer to select the most suitable candidates for use on the SPoTS. After that, several different system concepts have been generated and evaluated, the most promising concept being worked out in greater detail. km altitude. Each SPoTS satellite has a 50m diameter inflatable solar collector that focuses all received sunlight. Then, the received sunlight is further redirected by means of four pointing mirrors toward four individual customer satellites. A market-analysis study showed, that providing power to geo-stationary communication satellites during their eclipse would be most beneficial. At arrival at geo-stationary orbit, the focused beam has expended to such an extent that its density equals one solar flux. This means that customer satellites can continue to use their regular solar arrays during their eclipse for power generation, resulting in a satellite battery mass reduction. the customer satellites in geo-stationary orbit, the transmitted energy beams needs to be pointed with very high accuracy. Computations showed that for this degree of accuracy, sensors are needed, which are not mainstream nowadays. Therefore further research must be conducted in this area in order to make these high-accuracy-pointing systems commercially attractive for use on the SPoTS satellites around 2020. Total 20-year system lifetime cost for 18 SPoT satellites are estimated at approximately USD 6 billion [FY2001]. In order to compete with traditional battery-based satellite power systems or possible ground based wireless power transfer systems the price per kWh for the customer must be significantly lower than the present one

  18. Progress in Cleaning and Wet Processing for Kesterite Thin Film Solar Cells

    OpenAIRE

    B. Vermang, A. Mule, N. Gampa, S. Sahayaraj, S. Ranjbar, G. Brammertz, M. Meuris, J. Poortmans

    2016-01-01

    Copper indium gallium selenide/sulfide (CIGS) and copper zinc tin selenide/sulfide (CZTS) are two thin film photovoltaic materials with many similar properties. Therefore, three new processing steps – which are well-known to be beneficial for CIGS solar cell processing – are developed, optimized and implemented in CZTS solar cells. For all these novel processing steps an increase in minority carrier lifetime and cell conversion efficiency is measured, as compared to standard CZTS processing. ...

  19. Sensitizers for Aqueous-Based Solar Cells.

    Science.gov (United States)

    Li, Chun-Ting; Lin, Ryan Yeh-Yung; Lin, Jiann T

    2017-03-02

    Aqueous dye-sensitized solar cells (DSSCs) are attractive due to their sustainability, the use of water as a safe solvent for the redox mediators, and their possible applications in photoelectrochemical water splitting. However, the higher tendency of dye leaching by water and the lower wettability of dye molecules are two major obstacles that need to be tackled for future applications of aqueous DSSCs. Sensitizers designed for aqueous DSSCs are discussed based on their functions, such as modification of the molecular skeleton and the anchoring group for better stability against dye leaching by water, and the incorporation of hydrophilic entities into the dye molecule or the addition of a surfactant to the system to increase the wettability of the dye for more facile dye regeneration. Surface treatment of the photoanode to deter dye leaching or improve the wettability of the dye molecule is also discussed. Redox mediators designed for aqueous DSSCs are also discussed. The review also includes quantum-dot-sensitized solar cells, with a focus on improvements in QD loading and suppression of interfacial charge recombination at the photoanode.

  20. Fundamental Materials Research and Advanced Process Development for Thin-Film CIS-Based Photovoltaics: Final Technical Report, 2 October 2001 - 30 September 2005

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, T. J.; Li, S. S.; Crisalle, O. D.; Craciun, V.

    2006-09-01

    The objectives for this thin-film copper-indium-diselenide (CIS) solar cell project cover the following areas: Develop and characterize buffer layers for CIS-based solar cell; grow and characterize chemical-bath deposition of Znx Cd1-xS buffer layers grown on CIGS absorbers; study effects of buffer-layer processing on CIGS thin films characterized by the dual-beam optical modulation technique; grow epitaxial CuInSe2 at high temperature; study the defect structure of CGS by photoluminescence spectroscopy; investigate deep-level defects in Cu(In,Ga)Se2 solar cells by deep-level transient spectroscopy; conduct thermodynamic modeling of the isothermal 500 C section of the Cu-In-Se system using a defect model; form alpha-CuInSe2 by rapid thermal processing of a stacked binary compound bilayer; investigate pulsed non-melt laser annealing on the film properties and performance of Cu(In,Ga)Se2 solar cells; and conduct device modeling and simulation of CIGS solar cells.

  1. Nanoscale Measurements of the Surface Photovoltage in Cu(In,Ga)Se2, Cu2ZnSnS4, and Cu2ZnSnSe4 Thin Films: The Role of the Surface Electronics on the Efficiency of Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Du, H.; Romero, M. J.; Repins, I.; Teeter, G.; Noufi, R.; Al-Jassim, M. M.

    2011-01-01

    We report on recent advances in the development of nanoscale measurements of the surface photovoltage (SPV) based on scanning tunneling microscopy (STM) and its application to the kesterites Cu{sub 2}ZnSnS{sub 4} (CZTS) and Cu{sub 2}ZnSnSe{sub 4} (CZTSe). One critical aspect of the electronic structure of Cu(In, Ga)Se{sub 2} (CIGS) that has yet to be determined in their related kesterite compounds is the character of the surface electronics. In CIGS, spontaneous deviations in the stoichiometry of the surface cause a depletion (or even a type inversion) region that reinforces the CIGS homojunction. First-principle calculations predict that this inversion region will be more difficult to form in CZTS. In this contribution, the characteristics of the surface space charge region for both CIGS and CZTS(e) are investigated by STM. The implications of the results of these measurements on the future development of CZTS solar cells will be discussed.

  2. Experiment Based Teaching of Solar Cell Operation and Characterization Using the SolarLab Platform

    DEFF Research Database (Denmark)

    Spataru, Sergiu; Sera, Dezso; Kerekes, Tamas

    2014-01-01

    Experiment based teaching methods are a great way to get students involved and interested in almost any topic. This paper presents such a hands-on approach for teaching solar cell operation principles along with characterization and modelling methods. This is achieved with the SolarLab platform...... interfaces for exploring different solar cell principles and topics. The exercises presented in the current paper have been adapted from the original exercises developed for the SolarLab platform and are currently included in the Photovoltaic Power Systems courses (MSc and PhD level) taught at the Department...

  3. 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).

  4. Cost and Potential of Monolithic CIGS Photovoltaic Modules

    Energy Technology Data Exchange (ETDEWEB)

    Horowitz, Kelsey; Woodhouse, Michael

    2015-06-17

    A bottom-up cost analysis of monolithic, glass-glass Cu(In,Ga)(Se,S)2 (CIGS) modules is presented, illuminating current cost drivers for this technology and possible pathways to reduced cost. At 14% module efficiency, for the case of U.S. manufacturing, a manufacturing cost of $0.56/WDC and a minimum sustainable price of $0.72/WDC were calculated. Potential for reduction in manufacturing costs to below $0.40/WDC in the long-term may be possible if module efficiency can be increased without significant increase in $/m2 costs. The levelized cost of energy (LCOE) in Phoenix, AZ under different conditions is assessed and compared to standard c-Si.

  5. Unlikely Combination of Experiments With a Novel High-Voltage CIGS Photovoltaic Array: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    del Cueto, J. A.; Sekulic, B. R.

    2006-05-01

    A new high-voltage array comprising bipolar strings of copper indium gallium diselenide (CIGS) photovoltaic (PV) modules was inaugurated in 2005. It is equipped with a unique combination of tests, which likely have never before been deployed simultaneously within a single array: full current-voltage (I-V) traces, high-voltage leakage current measurements, and peak-power tracking or temporal stepped-bias profiling. The array nominally produces 1 kW power at 1 sun. The array's electrical characteristics are continuously monitored and controlled with a programmable electronic load interfaced to a data acquisition system (DAS), that also records solar and meteorological data. The modules are mounted with their frames electrically isolated from earth ground, in order to facilitate measurement of the leakage currents that arise between the high voltage bias developed in the series-connected cells and modules and their mounting frames. Because the DAS can perform stepped biasing of the array as a function of time, synchronous detection of the leakage current data with alternating bias is available. Leakage current data and their dependence on temperature and voltage are investigated. Array power data are analyzed across a wide range of varying illuminations and temperatures from the I-V traces. Array performance is also analyzed from an energy output perspective using peak-power tracking data.

  6. Graphene-Based Bulk-Heterojunction Solar Cells: A Review.

    Science.gov (United States)

    Singh, Eric; Nalwa, Hari Singh

    2015-09-01

    The current highest power-conversion efficiencies found for different types of solar cell devices range from 20% to 46%, depending on the nature of the photovoltaic materials used and device configuration. Graphene has emerged as an important organic photovoltaic material for photoenergy conversion, where graphene can be used as a transparent electrode, active interfacial layer, electron transport layer, hole transport layer, or electron/hole separation layer in fabricating solar cell devices. This review article briefly discusses some recent advances made in different types of photovoltaic materials, and then summarizes the current status of graphene-based bulk-heterojunction (BHJ) solar cells, including graphene-containing perovskite and tandem solar cell devices. Power-conversion efficiencies currently exceed 10% for heteroatom-doped multilayer graphene-based BHJ solar cells and 15.6% for graphene-containing perovskite-based solar cells. The role of graphene layer thickness, bending, thermal annealing, passivation, heteroatom doping, perovskite materials, and tandem solar cell structure on the photovoltaic performance of graphene-based solar cells is discussed. Besides aiming for high power-conversion efficiency, factors such as long-term environmental stability and degradation, and the cost-effectiveness of graphene-based solar cells for large-scale commercial production are challenging tasks.

  7. Optimization of Post-selenization Process of Co-sputtered CuIn and CuGa Precursor for 11.19% Efficiency Cu(In, Ga)Se2 Solar Cells

    Science.gov (United States)

    Cheng, Ke; Han, Kaikai; Kuang, Zhongcheng; Jin, Ranran; Hu, Junxia; Guo, Longfei; Liu, Ya; Lu, Zhangbo; Du, Zuliang

    2017-04-01

    In this work, CuInGa alloy precursor films are fabricated by co-sputtering of CuIn and CuGa targets simultaneously. After selenization in a tube-type rapid thermal annealing system under a Se atmosphere, the Cu(In, Ga)Se2 (CIGS) absorber layers are obtained. Standard soda lime glass (SLG)/Mo/CIGS/CdS/i-ZnO/ITO/Ag grid structural solar cells are fabricated based on the selenized CIGS absorbers. The influences of selenization temperatures on the composition, crystallinity, and device performances are systematically investigated by x-ray energy dispersive spectroscopy, x-ray diffraction, Raman spectroscopy, and the current density-voltage ( J- V) measurement. It is found that the elemental ratio of Cu/(In + Ga) strongly depends on the selenization temperatures. Because of the appropriate elemental ratio, a 9.92% conversion efficiency is reached for the CIGS absorber selenized at 560°C. After the additional optimization by pre-annealing treatment at 280°C before the selenization, a highest conversion efficiency of 11.19% with a open-circuit ( V oc) of 456 mV, a short-circuit ( J sc) of 40.357 mA/cm2 and a fill factor of 60.82% without antireflection coating has been achieved. Above 13% efficiency improvement was achievable. Our experimental findings presented in this work demonstrate that the post-selenization of co-sputtered CuIn and CuGa precursor is a promising way to fabricate high quality CIGS absorbers.

  8. 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.

  9. Understanding the Effect of Na in Improving the Performance of CuInSe2 Based Photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Dobson, Kevin D. [Univ. of Delaware, Newark, DE (United States)

    2015-11-17

    Cu(In,Ga)Se2 (CIGS) thin film photovoltaic technology is in the early stages of commercialization with an annual manufacturing capacity over 1 GW and has demonstrated the highest module efficiency of any of the thin film technologies. However there still is a lack of fundamental understanding of the relationship between the material properties and solar cell device operation. It is well known that the incorporation of a small amount of Na into the CIGS film during processing is essential for high efficiency devices. However, there are conflicting explanations for how Na behaves at the atomic scale. This report investigates how Na is incorporated into the CIGS device structure and evaluates the diffusion of Na into CIGS grain boundaries (GBs) and bulk crystallites. Participants: This project was carried out at the Institute of Energy Conversion at the University of Delaware, collaborating with the Rockett group at the University of Illinois Urbana-Champagne. Significant Findings: The significant outcomes of this project for each task include; Task 1.0: Effect of Na in Devices Fabricated on PVD Deposited CIGS; Na diffusion occurs through the Mo back contact via GBs driven by the presence of oxygen; Na reversibly compensates donor defects in CIGS GBs,Task 2.0: Na Incorporation in Single Crystal CIGS; and bulk Na diffusion proceeds rapidly such that grains are Na-saturated immediately following CIGS thin film manufacture. Industry Guidance: The presented results offer interesting concepts for modification of manufacturing processes of CIGS-based PV modules. Possible approaches to improve control of Na uptake and uniformly increase levels in CIGS films are highlighted for processes that employ either soda-lime glass or NaF as the Na source. Concepts include the potential of O2 or oxidative based treatments of Mo back contacts to improve Na diffusion through the metal film and increase Na uptake into the growing CIGS. This project has also offered

  10. Cocktails of paste coatings for performance enhancement of CuInGaS(2) thin-film solar cells.

    Science.gov (United States)

    An, Hee Sang; Cho, Yunae; Park, Se Jin; Jeon, Hyo Sang; Hwang, Yun Jeong; Kim, Dong-Wook; Min, Byoung Koun

    2014-01-22

    To fabricate low-cost and printable wide-bandgap CuInxGa1-xS2 (CIGS) thin-film solar cells, a method based on a precursor solution was developed. In particular, under this method, multiple coatings with two pastes with different properties (e.g., viscosity) because of the different binder materials added were applied. Paste A could form a thin, dense layer enabling a high-efficiency solar cell but required several coating and drying cycles for the desired film thickness. On the other hand, paste B could easily form one-micrometer-thick films by means of a one-time spin-coating process but the porous microstructure limited the solar cell performance. Three different configurations of the CIGS films (A + B, B + A, and A + B + A) were realized by multiple coatings with the two pastes to find the optimal stacking configuration for a combination of the advantages of each paste. Solar cell devices using these films showed a notable difference in their photovoltaic characteristics. The bottom dense layer increased the minority carrier diffusion length and enhanced the short-circuit current. The top dense layer could suppress interface recombination but exhibited a low optical absorption, thereby decreasing the photocurrent. As a result, the A + B configuration could be suggested as a desirable simple stacking structure. The solar cell with A + B coating showed a highly improved efficiency (4.66%) compared to the cell with a film prepared by paste B only (2.90%), achieved by simple insertion of a single thin (200 nm), dense layer between the Mo back contact and a thick porous CIGS layer.

  11. U.S. Surgeon General Calls for Crackdown on E-Cig Use in Teens

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_162443.html U.S. Surgeon General Calls for Crackdown on E-Cig ... product among American teens, according to a new U.S. Surgeon General's report that calls for a crackdown ...

  12. 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...

  13. Efficiency improvement of silicon nanostructure-based solar cells.

    Science.gov (United States)

    Huang, Bohr-Ran; Yang, Ying-Kan; Yang, Wen-Luh

    2014-01-24

    Solar cells based on a high-efficiency silicon nanostructure (SNS) were developed using a two-step metal-assisted electroless etching (MAEE) technique, phosphorus silicate glass (PSG) doping and screen printing. This process was used to produce solar cells with a silver nitrate (AgNO3) etching solution in different concentrations. Compared to cells produced using the single MAEE technique, SNS-based solar cells produced with the two-step MAEE technique showed an increase in silicon surface coverage of ~181.1% and a decrease in reflectivity of ~144.3%. The performance of the SNS-based solar cells was found to be optimized (~11.86%) in an SNS with a length of ~300 nm, an aspect ratio of ~5, surface coverage of ~84.9% and a reflectivity of ~6.1%. The ~16.8% increase in power conversion efficiency (PCE) for the SNS-based solar cell indicates good potential for mass production.

  14. Forbush Decrease Prediction Based on the Remote Solar Observations

    CERN Document Server

    Dumbovic, Mateja; Calogovic, Jasa

    2015-01-01

    We employ remote observations of coronal mass ejections (CMEs) and the associated solar flares to forecast the CME-related Forbush decreases, i.e., short-term depressions in the galactic cosmic-ray flux. The relationship between the Forbush effect at the Earth and remote observations of CMEs and associated solar flares is studied via a statistical analysis. Relationships between Forbush decrease magnitude and several CME/flare parameters was found, namely the initial CME speed, apparent width, source position, associated solar-flare class and the effect of successive-CME occurrence. Based on the statistical analysis, remote solar observations are employed for a Forbush-decrease forecast. For that purpose, an empirical probabilistic model is constructed that uses selected remote solar observations of CME and associated solar flare as an input, and gives expected Forbush-decrease magnitude range as an output. The forecast method is evaluated using several verification measures, indicating that as the forecast t...

  15. 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.

  16. 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...

  17. Organic Based Solar Cells with Morphology Control

    OpenAIRE

    Andersen, Thomas Rieks; Bundgaard, Eva; Jørgensen, Mikkel

    2013-01-01

    The field of organic solar cells has in the last years gone through an impressive development with efficiencies reported up to 12 %. For organic solar cells to take the leap from primarily being a laboratory scale technology to being utilized as renewable energy source, several issues need 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 morpholog...

  18. Estimating the frequency of extremely energetic solar events, based on solar, stellar, lunar, and terrestrial records

    CERN Document Server

    Schrijver, C J; Baltensperger, U; Cliver, E W; Guedel, M; Hudson, H S; McCracken, K G; Osten, R A; Peter, Th; Soderblom, D R; Usoskin, I G; Wolff, E W

    2012-01-01

    The most powerful explosions on the Sun [...] drive the most severe space-weather storms. Proxy records of flare energies based on SEPs in principle may offer the longest time base to study infrequent large events. We conclude that one suggested proxy, nitrate concentrations in polar ice cores, does not map reliably to SEP events. Concentrations of select radionuclides measured in natural archives may prove useful in extending the time interval of direct observations up to ten millennia, but as their calibration to solar flare fluences depends on multiple poorly known properties and processes, these proxies cannot presently be used to help determine the flare energy frequency distribution. Being thus limited to the use of direct flare observations, we evaluate the probabilities of large-energy solar explosions by combining solar flare observations with an ensemble of stellar flare observations. We conclude that solar flare energies form a relatively smooth distribution from small events to large flares, while...

  19. Effect of yoghurt or yoghurt serum on microbial quality of cig kofte.

    Science.gov (United States)

    Dogan, Mahmut; Cankurt, Hasan; Toker, Omer Said; Yetim, Hasan; Sagdic, Osman

    2014-07-01

    Cig kofte, raw meatball is a traditionally produced meat product in Turkey and some other Middle East countries. It is prepared from mixtures of finely minced raw beef, bulgur, onions, various spices and tap water. Cig kofte is an uncooked product and popularly consumed with lettuce and lemon juice. In this study, yoghurt or yoghurt serum (YS) were added to the mixtures of cig kofte instead of tap water to reduce microbial risks of the raw meatball. Additionally, the effects of yoghurt and YS on some physicochemical characteristics of cig kofte were investigated. Cig kofte is generally consumed within a few hours after the preparation because of its raw nature. Also, it is generally sold under unhygienic conditions in restaurants and restaurant-like places. For this purpose, reducing of the microbial load of cig kofte is important. In the results, Escherichia coli and Listeria monocytogenes were not detected in any samples. While lactic acid bacteria count increased by addition of yoghurt and YS, the number of other microorganisms except for total aerobic mesophilic bacteria (TAMB) were decreased. The aw values and% moisture contents of the samples were varied between 0.88-0.94 and 46.25-49.72, respectively. The pH values of the samples were slightly changed during the storage of 24 h while no changes detected in the control samples during the storage. In conclusion, it can be suggested that using the yoghurt or YS instead of tap water in the preparation of cig kofte might ensure the microbial safety, increase the nutritional value and its flavour or aroma.

  20. MICROCONTROLLER BASED SOLAR-TRACKING SYSTEM AND ITS IMPLEMENTATION

    Directory of Open Access Journals (Sweden)

    Okan BİNGÖL

    2006-02-01

    Full Text Available In this paper, a new micro-controller based solar-tracking system is proposed, implemented and tested. The scheme presented here can be operated as independent of the geographical location of the site of setting up. The system checks the position of the sun and controls the movement of a solar panel so that radiation of the sun comes normally to the surface of the solar panel. The developed-tracking system tracks the sun both in the azimuth as well as in the elevation plane. PC based system monitoring facility is also included in the design.

  1. Solar concentration by curved-base Fresnel lenses

    Science.gov (United States)

    Cosby, R. M.

    1977-01-01

    The solar concentration performance of idealized curved base line focusing Fresnel lenses is analyzed. A simple optical model was introduced to study the effects of base curvature and lens f-number. Thin lens ray tracing and the laws of reflection and refraction are used to develop expression for lens transmittance and image plane intensity profiles. The intensity distribution over the solar spectrum, lens dispersion effects, and absorption by the lens material are included in the analysis. Model capabilities include assessment of lens performance in the presence of small transverse tracking errors and the sensitivity of solar image characteristics to focusing.

  2. Solar combi system based on a mantle tank

    DEFF Research Database (Denmark)

    Yazdanshenas, Eshagh; Furbo, Simon

    2007-01-01

    A solar combisystem based on a mantle tank is investigated numerically and experimentally. Three different houses with four different radiator systems are considered for the simulations. The needed temperature for the auxiliary heater is determined for different houses and radiator systems....... The thermal performance of the solar combisystem is compared to the thermal performance of a solar domestic hot water system based on a mantle tank. In the experimental study, tank temperatures and the heat transfer coefficient for the top mantle for a discharge test is determined. The investigations showed...

  3. AMIGA project: Quantification of the isolation of 950 CIG galaxies

    CERN Document Server

    Verley, S; Verdes-Montenegro, L; Combes, F; Sabater, J; Sulentic, J; Bergond, G; Espada, D; Lisenfeld, U; Odewahn, S C

    2009-01-01

    The role of the environment on galaxy evolution is still not fully understood. In order to quantify and set limits on the role of nurture one must identify and study a sample of isolated galaxies. The AMIGA project "Analysis of the Interstellar Medium of Isolated GAlaxies" is doing a multi-wavelength study of a large sample of isolated galaxies in order to examine their interstellar medium and star formation activity. We processed data for 950 galaxies from the Catalogue of Isolated Galaxies (CIG, Karachentseva 1973) and evaluated their isolation using an automated star-galaxy classification procedure (down to M_B ~17.5) on large digitised POSS-I fields surrounding each isolated galaxy (within a projected radius of at least 0.5 Mpc). We defined, compared and discussed various criteria to quantify the degree of isolation for these galaxies: e.g. Karachentseva's revised criterion, local surface density computations, estimation of the external tidal force affecting each isolated galaxy. We found galaxies violati...

  4. Tantalum-based semiconductors for solar water splitting.

    Science.gov (United States)

    Zhang, Peng; Zhang, Jijie; Gong, Jinlong

    2014-07-07

    Solar energy utilization is one of the most promising solutions for the energy crises. Among all the possible means to make use of solar energy, solar water splitting is remarkable since it can accomplish the conversion of solar energy into chemical energy. The produced hydrogen is clean and sustainable which could be used in various areas. For the past decades, numerous efforts have been put into this research area with many important achievements. Improving the overall efficiency and stability of semiconductor photocatalysts are the research focuses for the solar water splitting. Tantalum-based semiconductors, including tantalum oxide, tantalate and tantalum (oxy)nitride, are among the most important photocatalysts. Tantalum oxide has the band gap energy that is suitable for the overall solar water splitting. The more negative conduction band minimum of tantalum oxide provides photogenerated electrons with higher potential for the hydrogen generation reaction. Tantalates, with tunable compositions, show high activities owning to their layered perovskite structure. (Oxy)nitrides, especially TaON and Ta3N5, have small band gaps to respond to visible-light, whereas they can still realize overall solar water splitting with the proper positions of conduction band minimum and valence band maximum. This review describes recent progress regarding the improvement of photocatalytic activities of tantalum-based semiconductors. Basic concepts and principles of solar water splitting will be discussed in the introduction section, followed by the three main categories regarding to the different types of tantalum-based semiconductors. In each category, synthetic methodologies, influencing factors on the photocatalytic activities, strategies to enhance the efficiencies of photocatalysts and morphology control of tantalum-based materials will be discussed in detail. Future directions to further explore the research area of tantalum-based semiconductors for solar water splitting

  5. Solar-rechargeable battery based on photoelectrochemical water oxidation: Solar water battery.

    Science.gov (United States)

    Kim, Gonu; Oh, Misol; Park, Yiseul

    2016-09-15

    As an alternative to the photoelectrochemical water splitting for use in the fuel cells used to generate electrical power, this study set out to develop a solar energy rechargeable battery system based on photoelectrochemical water oxidation. We refer to this design as a "solar water battery". The solar water battery integrates a photoelectrochemical cell and battery into a single device. It uses a water oxidation reaction to simultaneously convert and store solar energy. With the solar water battery, light striking the photoelectrode causes the water to be photo-oxidized, thus charging the battery. During the discharge process, the solar water battery reduces oxygen to water with a high coulombic efficiency (>90%) and a high average output voltage (0.6 V). Because the reduction potential of oxygen is more positive [E(0) (O2/H2O) = 1.23 V vs. NHE] than common catholytes (e.g., iodide, sulfur), a high discharge voltage is produced. The solar water battery also exhibits a superior storage ability, maintaining 99% of its specific discharge capacitance after 10 h of storage, without any evidence of self-discharge. The optimization of the cell design and configuration, taking the presence of oxygen in the cell into account, was critical to achieving an efficient photocharge/discharge.

  6. Solar-rechargeable battery based on photoelectrochemical water oxidation: Solar water battery

    Science.gov (United States)

    Kim, Gonu; Oh, Misol; Park, Yiseul

    2016-09-01

    As an alternative to the photoelectrochemical water splitting for use in the fuel cells used to generate electrical power, this study set out to develop a solar energy rechargeable battery system based on photoelectrochemical water oxidation. We refer to this design as a “solar water battery”. The solar water battery integrates a photoelectrochemical cell and battery into a single device. It uses a water oxidation reaction to simultaneously convert and store solar energy. With the solar water battery, light striking the photoelectrode causes the water to be photo-oxidized, thus charging the battery. During the discharge process, the solar water battery reduces oxygen to water with a high coulombic efficiency (>90%) and a high average output voltage (0.6 V). Because the reduction potential of oxygen is more positive [E0 (O2/H2O) = 1.23 V vs. NHE] than common catholytes (e.g., iodide, sulfur), a high discharge voltage is produced. The solar water battery also exhibits a superior storage ability, maintaining 99% of its specific discharge capacitance after 10 h of storage, without any evidence of self-discharge. The optimization of the cell design and configuration, taking the presence of oxygen in the cell into account, was critical to achieving an efficient photocharge/discharge.

  7. 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%.

  8. 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.

  9. Hybrid density functional theory study of Cu(In1−xGaxSe2 band structure for solar cell application

    Directory of Open Access Journals (Sweden)

    Xu-Dong Chen

    2014-08-01

    Full Text Available Cu(In1−xGaxSe2 (CIGS alloy based thin film photovoltaic solar cells have attracted more and more attention due to its large optical absorption coefficient, long term stability, low cost and high efficiency. However, the previous theoretical investigation of this material with first principle calculation cannot fulfill the requirement of experimental development, especially the accurate description of band structure and density of states. In this work, we use first principle calculation based on hybrid density functional theory to investigate the feature of CIGS, with B3LYP applied in the CuIn1−xGaxSe2 stimulation of the band structure and density of states. We report the simulation of the lattice parameter, band gap and chemical composition. The band gaps of CuGaSe2, CuIn0.25Ga0.75Se2, CuIn0.5Ga0.5Se2, CuIn0.75Ga0.25Se2 and CuInSe2 are obtained as 1.568 eV, 1.445 eV, 1.416 eV, 1.275 eV and 1.205 eV according to our calculation, which agree well with the available experimental values. The band structure of CIGS is also in accordance with the current theory.

  10. New solar selective coating based on carbon nanotubes

    Science.gov (United States)

    Abendroth, Thomas; Leupolt, Beate; Mäder, Gerrit; Härtel, Paul; Grählert, Wulf; Althues, Holger; Kaskel, Stefan; Beyer, Eckhard

    2016-05-01

    Carbon nanotubes (CNTs) can be applied to assemble a new type of solar selective coating system for solar thermal applications. In this work the predominant absorption processes occurring by interaction with π-plasmon and Van Hove singularities (VHS) were investigated by UV-VIS-NIR spectroscopy and ellipsometry. Not only optical properties for as deposited SWCNT thin films itself, but also the potential for systematic tailoring will be presented. Besides low cost technologies required, the adjustability of optical properties, as well as their thermal stability render CNT based solar selective coatings as promising alternative to commercially available coating systems.

  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. Study of Emergency Power Based on Solar Battery Charging

    Directory of Open Access Journals (Sweden)

    Wang Lei

    2016-01-01

    Full Text Available To study an emergency power based on solar battery charging. Based on the electric-generation principle of solar panel, solar energy is changed into electrical energy. Through voltage conversion circuit and filter circuit, electrical energy is stored in the energy storage battery. The emergency power realizes the conversion from solar energy to electrical energy. The battery control unit has the function of PWM (Pulse-Width Modulation charging, overcharging protection, over-discharging protection and over-current protection. It also realizes the fast and safe charging of energy storage battery. The emergency power could provide both 12V AC power for emergency equipment such as miniature PSA oxygen concentrator and 5V USB for electronic equipment (mobile phone, GPS device, rechargeable light, etc..

  13. 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.

  14. Organic Based Solar Cells with Morphology Control

    DEFF Research Database (Denmark)

    Andersen, Thomas Rieks

    The field of organic solar cells has in the last years gone through an impressive development with efficiencies reported up to 12 %. For organic solar cells to take the leap from primarily being a laboratory scale technology to being utilized as renewable energy source, several issues need...... of the nanoparticles was investigated both internally and externally, both were attempted to be controlled by variation in preparation solvent and particle sizes. The inks were slot-die coated on both the R2R coater and mini roll coater but only after a number of inks modifications and adjustments of the coating...... deposition techniques which have been downscaled from the R2R coater i.e. slot-die coating and flexographic printing. Thereby allowing the device optimizations to be transferred almost directly from small to large scale. This is in contrast to devices prepared by spincoating. Another advantage...

  15. Silicon based solar cells using a multilayer oxide as emitter

    Science.gov (United States)

    Bao, Jie; Wu, Weiliang; Liu, Zongtao; Shen, Hui

    2016-08-01

    In this work, n-type silicon based solar cells with WO3/Ag/WO3 multilayer films as emitter (WAW/n-Si solar cells) were presented via simple physical vapor deposition (PVD). Microstructure and composition of WAW/n-Si solar cells were studied by TEM and XPS, respectively. Furthermore, the dependence of the solar cells performances on each WO3 layer thickness was investigated. The results indicated that the bottom WO3 layer mainly induced band bending and facilitated charge-carriers separation, while the top WO3 layer degraded open-circuit voltage but actually improved optical absorption of the solar cells. The WAW/n-Si solar cells, with optimized bottom and top WO3 layer thicknesses, exhibited 5.21% efficiency on polished wafer with area of 4 cm2 under AM 1.5 condition (25 °C and 100 mW/cm2). Compared with WO3 single-layer film, WAW multilayer films demonstrated better surface passivation quality but more optical loss, while the optical loss could be effectively reduced by implementing light-trapping structures. These results pave a new way for dopant-free solar cells in terms of low-cost and facile process flow.

  16. Fabrication of CIGS thin films by using spray pyrolysis and post-selenization

    Science.gov (United States)

    Kim, Seong Yeon; Kim, JunHo

    2012-06-01

    We fabricated Cu(In1- x Ga x )Se2 ( x: 0 ˜ 0.4) thin films by using ultrasonic spray pyrolysis and post-selenization. First, we made Cu(In1- x Ga x )S2 ( x: 0 ˜ 0.4) films by ultrasonic spray pyrolysis under an air environment. Then, we converted as-sprayed Cu(In1- x Ga x )S2 (CIGS) films to Cu-(In1- x Ga x )Se2 (CIGSe) films through post-selenization. For all Ga fractions, the sprayed CIGS films were well recrystallized into poly-crystalline CIGSe films with a dominant (112) texture, which was confirmed by X-ray diffraction, Raman spectroscopy and energy dispersive X-ray analyses. This result indicates that CIGSe films with any amount of Ga substitution can be made by converting sprayed CIGS to CIGSe with post-selenization.

  17. Investigation of crystallization behavior of CIG-Se bi-layer thin films.

    Science.gov (United States)

    Park, Mi Sun; Sung, Shi-Joon; Kim, Dae-Hwan; Kang, Jin-Kyu

    2012-04-01

    Copper indium gallium diselenide (CIGSe) thin film was fabricated via a thermal treatment of GIG-Se bi-layer thin films. A CIG layer was prepared first, by a chemical solution deposition (CSD) process. The Se layer was deposited separately on the CIG layer by evaporation. The GIG-Se bi-layer then underwent a thermal treatment to cause a reaction between the two layers. In order to investigate the mechanism of CIG-Se bi-layer crystallization, the thermal treatment temperature was varied. The properties of the prepared CIGSe2 thin films were analyzed using X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectrometry (EDS), and UV-visible spectrophotometry.

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

    OpenAIRE

    Chung Ping Liu; Ming Wei Chang; Chuan Lung Chuang; Nien Po Chen

    2014-01-01

    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 diamet...

  19. 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)

  20. A self-calibrating led-based solar test platform

    DEFF Research Database (Denmark)

    Krebs, Frederik C; Sylvester-Hvid, Kristian O.; Jørgensen, Mikkel

    2011-01-01

    A compact platform for testing solar cells is presented. The light source comprises a multi-wavelength high-power LED (light emitting diode) array allowing the homogenous illumination of small laboratory solar cell devices (substrate size 50 × 25 mm) within the 390–940 nm wavelength range......, it is possible to perform all the commonly employed measurements on the solar cell at very high speed without moving the sample. In particular, the LED-based illumination system provides an alternative to light-biased incident photon-to-current efficiency measurement to be performed which we demonstrate. Both...... top and bottom contact is possible and the atmosphere can be controlled around the sample during measurements. The setup was developed for the field of polymer and organic solar cells with particular emphasis on enabling different laboratories to perform measurements in the same manner and obtain...

  1. Progress Toward an Updated National Solar Radiation Data Base

    Energy Technology Data Exchange (ETDEWEB)

    Wilcox, S.; Anderberg, M.; George, R.; Marion, W.; Myers, D.; Renne, D.; Beckman, W.; DeGaetano, A.; Gueymard, C.; Perez, R.; Plantico, M.; Stackhouse, P.; Vignola, F.

    2005-01-01

    Progress is reported on an updated National Solar Radiation Database (NSRDB). Focus on this year's work was on preparing a test-year database for evaluating several solar radiation models that could be used to replace the METSTAT model used in the original 1961-1990 NSRDB. That model is no longer compatible with cloud observations reported by the National Weather Service. We have also included a satellite-based model that will increase the spatial resolution of solar radiation for GIS or mapping applications. Work also included development of improved estimates for aerosols, water vapor, and ozone. High-quality solar measurements were obtained for 33 sites near National Weather Service stations, and model runs were completed for test years 1999 and 2000.

  2. Novel Flexible Plastic-Based Solar Cells

    Science.gov (United States)

    2012-10-19

    different types of solar cells: 1) Synthesis of hole transporting low band gap polymers, development of ligand exchange in a nanocomposite, and...a) Energy band diagram of the device structure, (b) The SEM image of the cross section of the devices, (c) I-V characteristics of the TiO2 -PbS... band gap polymers have been investigated to exhibit PCE as high as 8~9% with a PCBM derivative (PC71BM). As a replacement of a typical organic

  3. 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.

  4. Innovative laser based solar cell scribing

    Science.gov (United States)

    Frei, Bruno; Schneeberger, Stefan; Witte, Reiner

    2011-03-01

    The solar photovoltaic market is continuously growing utilizing boths crystalline silicon (c-Si) as well as thin film technologies. This growth is directly dependant on the manufacturing costs for solar cells. Factors for cost reduction are innovative ideas for an optimization of precision and throughput. Lasers are excellent tools to provide highly efficient processes with impressive accuracy. They need to be used in combination with fast and precise motion systems for a maximum gain in the manufacturing process, yielding best cost of ownership. In this article such an innovative solution is presented for laser scribing in thin film Si modules. A combination of a new glass substrate holding system combined with a fast and precise motion system is the foundation for a cost effective scribing machine. In addition, the advantages of fiber lasers in beam delivery and beam quality guarantee not only shorter setup and down times but also high resolution and reproducibility for the scribing processes P1, P2 and P3. The precision of the whole system allows to reduce the dead zone to a minimum and therefore to improve the efficiency of the modules.

  5. Graphene-based transparent electrodes for hybrid solar cells

    Directory of Open Access Journals (Sweden)

    Pengfei eLi

    2014-11-01

    Full Text Available The graphene-based transparent and conductive films were demonstrated to be cost-effective electrodes working in organic-inorganic hybrid Schottky solar cells. Large area graphene films were produced by chemical vapor deposition (CVD on copper foils and transferred onto glass as transparent electrodes. The hybrid solar cell devices consist of solution processed poly (3, 4-ethlenedioxythiophene: poly (styrenesulfonate (PEDOT: PSS which is sandwiched between silicon wafer and graphene electrode. The solar cells based on graphene electrodes, especially those doped with HNO3, has comparable performance to the reference devices using commercial indium tin oxide (ITO. Our work suggests that graphene-based transparent electrode is a promising candidate to replace ITO.

  6. 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

  7. Dataset demonstrating the modeling of a high performance Cu(In,Ga)Se2 absorber based thin film photovoltaic cell.

    Science.gov (United States)

    Asaduzzaman, Md; Bahar, Ali Newaz; Bhuiyan, Mohammad Maksudur Rahman

    2017-04-01

    The physical data of the semiconductor materials used in the design of a CIGS absorber based thin film photovoltaic cell have been presented in this data article. Besides, the values of the contact parameter and operating conditions of the cell have been reported. Furthermore, by conducting the simulation with data corresponding to the device structure: soda-lime glass (SLG) substrate/Mo back-contact/CIGS absorber/CdS buffer/intrinsic ZnO/Al-doped ZnO window/Al-grid front-contact, the solar cell performance parameters such as open circuit voltage [Formula: see text], short circuit current density [Formula: see text], fill factor [Formula: see text], efficiency [Formula: see text], and collection efficiency [Formula: see text] have been analyzed.

  8. Increasing solar cell efficiencies based on Cu(In,Ga)Se{sub 2} after a specific chemical and oxidant treatment

    Energy Technology Data Exchange (ETDEWEB)

    Canava, B.; Etcheberry, A. [Institut de Reactivite, Electrochimie et Microporosites (UMR CNRS 8637), Universite de Versailles, 45 Avenue des Etats-Unis, 78035 Versailles (France); Roussel, O.; Guillemoles, J.F.; Lincot, D. [Institut de Recherche et de Developpement sur l' Energie Photovoltaique (UMR 7174 CNRS-ENSCP-EDF - EDF R and D), Centre de Chatou, 6 quai Watier, 78400 Chatou (France)

    2006-09-15

    Oxidative etching treatments based on bromine water mixtures have been studied on polycrystalline thin films of Cu(In,Ga)Se{sub 2}. This treatment enables preparation of planar, smooth and specular surfaces whose chemical properties are well defined, despite the small thickness of the layers ({approx}2 {mu}m). After device completion, the electronic properties (I-V curve, spectral response) were studied and correlated to device performances. Theses conditions allow to re-engineer damaged or aged surfaces of CIGS and to recover high photovoltaic performances. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  9. Metallicity calibration for solar type stars based on red spectra

    Institute of Scientific and Technical Information of China (English)

    Jing-Kun Zhao; Gang Zhao; Yu-Qin Chen; A-Li Luo

    2011-01-01

    Based on a high resolution and high signal-to-noise ratio (S/N) spectral analysis of 90 solar-type stars, we have established several new metallicity calibrations in the Teff range [5600, 6500] K based on red spectra with the wavelength range of 560-880 nm. The new metallicity calibrations are applied to determine the metallicity of solar analogs selected from Sloan Digital Sky Survey (SDSS) spectra. There is a good consistent result with the adopted value presented in SDSS-DR7 and a small scatter of 0.26 dex for stars with S/N > 50 being obtained. This study provides a new reliable way to derive the metallicity for solar-like stars with low resolution spectra.In particular, our calibrations are useful for finding metal-rich stars, which are missing in the SEGUE Stellar Parameter Pipeline.

  10. Dye-sensitized solar cells based on bisindolylmaleimide derivatives

    Institute of Scientific and Technical Information of China (English)

    Qiong ZHANG; Zhijun NING; Hongcui PEI; Wenjun WU

    2009-01-01

    Three organic dyes based on bisindolylmaleimide derivatives (11, 12 and 13) were synthesized and investigated as sensitizers for the application in nanocrystalline TiO2 solar cells. The indole group,maleimide group and carboxylic group functioned as electron donor, acceptor and anchoring group, respec-tively. Solar-to-electrical energy conversion efficiencies under simulated amplitude-modulated 1.5 irradiation based on 12 and of 1.87% and 1.50% for 13 and 11,respectively. The open circuit voltage Voc was demon-strated to be enhanced by the introduction of dodecyl or benzyl moieties on the indole groups. The nonplanar structure of bisindolylmaleimide was proven to be effective in aggregation resistance. This work suggests that organic sensitizers with maleimide as electron acceptor are promising candidates as organic sensiti-zers in dye-sensitized solar cells.

  11. Forbush Decrease Prediction Based on Remote Solar Observations

    Science.gov (United States)

    Dumbovic, Mateja; Vrsnak, Bojan; Calogovic, Jasa

    2016-04-01

    We study the relation between remote observations of coronal mass ejections (CMEs), their associated solar flares and short-term depressions in the galactic cosmic-ray flux (so called Forbush decreases). Statistical relations between Forbush decrease magnitude and several CME/flare parameters are examined. In general we find that Forbush decrease magnitude is larger for faster CMEs with larger apparent width, which is associated with stronger flares that originate close to the center of the solar disk and are (possibly) involved in a CME-CME interaction. The statistical relations are quantified and employed to forecast expected Forbush decrease magnitude range based on the selected remote solar observations of the CME and associated solar flare. Several verification measures are used to evaluate the forecast method. We find that the forecast is most reliable in predicting whether or not a CME will produce a Forbush decrease with a magnitude >3 %. The main advantage of the method is that it provides an early prediction, 1-4 days in advance. Based on the presented research, an online forecast tool was developed (Forbush Decrease Forecast Tool, FDFT) available at Hvar Observatory web page: http://oh.geof.unizg.hr/FDFT/fdft.php. We acknowledge the support of Croatian Science Foundation under the project 6212 „Solar and Stellar Variability" and of European social fond under the project "PoKRet".

  12. 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%.

  13. The impact of selenisation on damp heat degradation of the CIGS back contact molybdenum

    NARCIS (Netherlands)

    Theelen, M.; Tomassini, M.; Barreau, N.; Steijvers, H.; Branca, A.; Harel, S.; Vroon, Z.; Zeman, M.

    2012-01-01

    Molybdenum (Mo) degrades under the influence of damp heat, thereby reducing the output of CIGS PV. In this study, Mo layers were deposited on a glass substrate by magnetron sputtering, thereby varying the deposition pressure and the addition of selenium. These samples were thoroughly analysed and de

  14. Cu(In,Ga)(Se,S)2 solar cell research in Solar Frontier: Progress and current status

    Science.gov (United States)

    Kato, Takuya

    2017-04-01

    As the largest manufacturer of Cu(In,Ga)(Se,S)2 (CIGS) thin-film photovoltaic modules with more than 1 GW/year production volume, Solar Frontier K.K. has continuously improved module performance and small-area cell efficiencies in the laboratory. Because of our low-cost and environmentally-friendly process, Solar Frontier’s CIGS is a promising technology for the mass production of photovoltaic modules to fill ever-increasing demand. Recently we have achieved certified efficiencies of 22.3 and 22.0% on CdS-buffered and Cd-free buffered small-area cells, respectively, as well as 18.6% on a Cd-free mini-module. In this paper, a review of our CIGS technology and recent progress on the development of the module and the small-area cell is presented.

  15. 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.

  16. Electron trapping in higher adduct fullerene-based solar cells

    NARCIS (Netherlands)

    Lenes, M.; Shelton, S.W.; Sieval, A.B.; Kronholm, D.F.; Hummelen, J.C.; Blom, P.W.M.

    2009-01-01

    Here, the performance of bulk-heterojunction solar cells based on a series of bisadduct analogues of commonly used derivatives of C60 and C 70, such PCBMs and theirthienyl versions, is investigated. Dueto their higher lowest unoccupied molecular orbital an increase in open-circuit voltage and thus p

  17. Photo electrochemical and organic-based solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, N.S. [California Institute of Technology, Pasadena, CA (United States); Kamat, P. [Univ. of Notre Dame, IN (United States); Spitler, M. [Boston Univ., MA (United States)

    1996-09-01

    Research in solar photoconversion has resulted in significant advances in the fields of photoelectrochemistry and dye-sensitized solar cells. Progress is also evident in the understanding of solid state organic systems for energy transduction. It is evident, however, that the examination in this report of the accomplishments in these areas serves to highlight the great extent of research that is necessary to establish a technology base sufficient for practical application. Recommendations are made in this report on the directions that this research should take.

  18. 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.

  19. Solar optics-based active panel for solar energy storage and disinfection of greywater.

    Science.gov (United States)

    Lee, W; Song, J; Son, J H; Gutierrez, M P; Kang, T; Kim, D; Lee, L P

    2016-09-01

    Smart city and innovative building strategies are becoming increasingly more necessary because advancing a sustainable building system is regarded as a promising solution to overcome the depleting water and energy. However, current sustainable building systems mainly focus on energy saving and miss a holistic integration of water regeneration and energy generation. Here, we present a theoretical study of a solar optics-based active panel (SOAP) that enables both solar energy storage and photothermal disinfection of greywater simultaneously. Solar collector efficiency of energy storage and disinfection rate of greywater have been investigated. Due to the light focusing by microlens, the solar collector efficiency is enhanced from 25% to 65%, compared to that without the microlens. The simulation of greywater sterilization shows that 100% disinfection can be accomplished by our SOAP for different types of bacteria including Escherichia coli. Numerical simulation reveals that our SOAP as a lab-on-a-wall system can resolve the water and energy problem in future sustainable building systems.

  20. Solar cells based on organic materials; Solceller av organisk materiale

    Energy Technology Data Exchange (ETDEWEB)

    Samuelsen, Emil J.; Breiby, Dag W.

    2009-07-01

    Organic Solar cells are still in the early research phase, and the efficiency so far is merely 5 - 6 %. But since this field of technology is recognised to be highly promising and potentially important, the research and development effort is formidable, and one foresees an improvement in efficiency of 10 -15%. Introduction: Today's commercial solar cells are based on the semiconductive material silicium with an energy efficiency close to 15% , i e this share of the solar energy which hit the cell will be transformed into electric energy. Research versions of silicium cells have efficiencies up towards 25% and certain combined cells from other inorganic materials may attain 30 - 40%. For so called third generation solar cells one even expects figures up to 60%. Organic solar cells are not developed in order to compete with Si cells, but to complement them. They will be cheap, light, pliable and rugged, well suited for use under special conditions, as cruises and expeditions in mountains and wilderness, and the cells may be integrated in equipment and textiles. (EW)

  1. Natural Pigment-Based Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    A.R. Hernández-Martínez

    2012-03-01

    Full Text Available The performance of dye-sensitized solar cells (DSSC based on natural dyes extracted from five different sources is reported. These are inexpensive, have no nutritional use, and are easy to find in Mexico. The solar cells were assembled using a thin film and a TiO2 mesoporous film on ITO-coated glass; these films were characterized by FTIR. The extracts were characterized using UV–Vis and typical I-V curves were obtained for the cells. The best performance was for Punica Granatum with a solar energy conversion efficiency of 1.86%, with a current density Jsc of 3.341 mA/cm2using an incident irradiation of 100 mW/cm2 at 25 ºC.

  2. Progress on an Updated National Solar Radiation Data Base: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Wilcox, S.; Anderberg, M.; George, R.; Marion, W.; Myers, D.; Renne, D.; Beckman, W.; DeGaetano, A.; Gueymard, C.; Perez, R.; Plantico, M.; Stackhouse, P.; Vignola, F.

    2004-03-01

    In 1992, The National Renewable Energy Laboratory (NREL) released the 1961-1990 National Solar Radiation Data Base (NSRDB), a 30-year set of hourly solar radiation data. In April 2003, NREL convened a meeting of experts to investigate issues concerning a proposed update of the NSRDB. The panel determined that an important difficulty posed by the update was the shift from manual to automated cloud observations at National Weather Service stations in the United States. The solar model used in the original NSRDB relied heavily on the methodology and resolution of the manual cloud observations. The meeting participants recommended that NREL produce a plan for creating an update using currently available meteorological observations and satellite imagery. This paper describes current progress toward a plan for an updated NSRDB.

  3. Improvement of Film Quality in CuInSe2 Thin Films Fabricated by a Non-Vacuum, Nanoparticle-Based Approach

    Science.gov (United States)

    Zhang, Yiwen; Ito, Manabu; Tamura, Tomoaki; Yamada, Akira; Konagai, Makoto

    2011-04-01

    To improve the quality of CuInSe2 (CIS) thin films fabricated by a non-vacuum, nanoparticle-based approach, in this study, two categories of nanoparticles, Cu (InGa) Se2 (CIGS) nanoparticles and copper selenide (Cu-Se) with indium selenide (In-Se) nanoparticles are investigated. It is found that the Cu-Se with In-Se nanoparticles show a higher crystallization velocity than CIGS nanoparticles. The films obtained from Cu-Se with In-Se nanoparticles exhibit higher crystallinity with a larger grain size. Thiourea is applied as a sintering additive during the selenization process. It is clarified that the addition of thiourea is very effective for grain growth and the fabrication of a dense CIS layer. The cell performance is measured under Air Mass 1.5 irradiation. The efficiency of the solar cell, fabricated using Cu-Se, In-Se nanoparticles with thiourea, is 2.15%, higher than that of the solar cell fabricated using CIGS nanoparticles, which is 0.28%.

  4. MCU-Based Solar Powered Chicken Feeder

    Directory of Open Access Journals (Sweden)

    Elenor M. Reyes

    2015-12-01

    Full Text Available Poultry is a great potential industry particularly in Batangas Province. The method of feeding chicken needs to be considered as chicken must be fed regularly to be more productive. The conventional method of feeding chicken is the need to continuously provide the food, be alert and conscious on the food remaining in cages and to feed the chickens in a correct period of time to avoid the decline of the production. Growers also find it difficult to manage their businesses effectively because they need to be around the cages every now and then to monitor the poultry. Timing and exactness are the key to provide a uniform time in feeding the chickens. This will benefit the owner of the business in terms of time and effort. Another advantage of this project is in terms of savings to the owner of the poultry business. This technology was designed to automatically feed chickens at a given period of time and to give alarm when the feeds are running out of supply. The power to be supplied to this prototype will be drawn from the sun by means of solar panels and will be stored in typical car battery. The feeds will be stored in a container and evenly distributed by using a conveyor to the feeding basin of the poultry. It will be more efficient than manual conventional way of feeding because less effort will be needed in feeding the chickens and less feeds will be wasted. In addition to that, the stored power can also be used for lighting purposes for the growers to save energy and energy bills.

  5. Solar Energy Based Automated Irrigation System

    Directory of Open Access Journals (Sweden)

    Prof. Lodhi A. K.

    2013-09-01

    Full Text Available In the field of agriculture, use of proper method of irrigation is important because the main reason is the lack of rains {&} scarcity of land reservoir water. The continuous extraction of water from earth is reducing the water level due to which lot of land is coming slowly in the zones of un-irrigated land. Another very important reason of this is due to unplanned use of water due to which a significant amount of water goes waste. For this purpose; we use this automatic plant irrigation system. In this project we use solar energy which is used to operate the irrigation pump. The circuit comprises of sensor parts built using op-amp IC LM358. Op-amp are configured here as a comparator. Two stiff copper wires are inserted in the soil to sense whether the soil is wet or dry. The Microcontroller is used to control the whole system by monitoring the sensors and when sensors sense the dry condition then the microcontroller will send command to relay driver IC the contacts of which are used to switch on the motor and it will switch off the motor when all the sensors are in wet condition. The microcontroller does the above job as it receives the signal from the sensors through the output of the comparator, and these signals operate under the control of software which is stored in ROM of the Microcontroller. The condition of the pump i.e., ON/OFF is displayed on a 16X2 LCD

  6. Prediction of global solar irradiance based on time series analysis: Application to solar thermal power plants energy production planning

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Luis; Marchante, Ruth; Cony, Marco [Investigaciones y Recursos Solares Avanzados (IrSOLaV), Tres Cantos 2 8045 (Spain); Zarzalejo, Luis F.; Polo, Jesus; Navarro, Ana [Energy Department, CIEMAT, Madrid 28040 (Spain)

    2010-10-15

    Due to strong increase of solar power generation, the predictions of incoming solar energy are acquiring more importance. Photovoltaic and solar thermal are the main sources of electricity generation from solar energy. In the case of solar thermal energy plants with storage energy system, its management and operation need reliable predictions of solar irradiance with the same temporal resolution as the temporal capacity of the back-up system. These plants can work like a conventional power plant and compete in the energy stock market avoiding intermittence in electricity production. This work presents a comparisons of statistical models based on time series applied to predict half daily values of global solar irradiance with a temporal horizon of 3 days. Half daily values consist of accumulated hourly global solar irradiance from solar raise to solar noon and from noon until dawn for each day. The dataset of ground solar radiation used belongs to stations of Spanish National Weather Service (AEMet). The models tested are autoregressive, neural networks and fuzzy logic models. Due to the fact that half daily solar irradiance time series is non-stationary, it has been necessary to transform it to two new stationary variables (clearness index and lost component) which are used as input of the predictive models. Improvement in terms of RMSD of the models essayed is compared against the model based on persistence. The validation process shows that all models essayed improve persistence. The best approach to forecast half daily values of solar irradiance is neural network models with lost component as input, except Lerida station where models based on clearness index have less uncertainty because this magnitude has a linear behaviour and it is easier to simulate by models. (author)

  7. 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.

  8. Impact of atmospheric species on copper indium gallium selenide solar cell stability: An overview

    NARCIS (Netherlands)

    Theelen, M.

    2016-01-01

    An overview of the measurement techniques and results of studies on the stability of copper indium gallium selenide (CIGS) solar cells and their individual layers in the presence of atmospheric species is presented: in these studies, Cu(In,Ga)Se2 solar cells, their molybdenum back contact, and their

  9. 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.

  10. Solar water heating system for a lunar base

    Science.gov (United States)

    Somers, Richard E.; Haynes, R. Daniel

    1992-01-01

    An investigation of the feasibility of using a solar water heater for a lunar base is described. During the investigation, computer codes were developed to model the lunar base configuration, lunar orbit, and heating systems. Numerous collector geometries, orientation variations, and system options were identified and analyzed. The results indicate that the recommended solar water heater could provide 88 percent of the design load and would not require changes in the overall lunar base design. The system would give a 'safe-haven' water heating capability and use only 7 percent to 10 percent as much electricity as an electric heating system. As a result, a fixed position photovoltaic array can be reduced by 21 sq m.

  11. Performance Evaluation of a Nanofluid-Based Direct Absorption Solar Collector with Parabolic Trough Concentrator

    OpenAIRE

    Xu, Guoying; Chen, Wei; Deng, Shiming; Zhang, Xiaosong; Zhao, Sainan

    2015-01-01

    Application of solar collectors for hot water supply, space heating, and cooling plays a significant role in reducing building energy consumption. For conventional solar collectors, solar radiation is absorbed by spectral selective coating on the collectors’ tube/plate wall. The poor durability of the coating can lead to an increased manufacturing cost and unreliability for a solar collector operated at a higher temperature. Therefore, a novel nanofluid-based direct absorption solar collector...

  12. High efficient solar tracker based on a simple shutter structure

    Science.gov (United States)

    Chen, Jin-Jia; Liu, Te-Shu; Huang, Kuang-Lung; Lin, Po-Chih

    2013-09-01

    In many photovoltaic (PV) or sunlight-illumination systems, solar trackers are always essential to obtain high energy/flux concentration efficiency, and that would lead to increase cost and extra power consumption due to the complex structure and heavy weight of the trackers. To decrease the cost while without sacrificing efficiency, a Fresnellens concentrator incorporated with a simple and cheap shutter, which consists of high reflective mirrors instead of conventional trackers, is proposed in this paper to provide solar tracking during the daytime. Thus, the time-variant and slant-incident sunlight rays can be redirected to vertically incident upon the surface of the Fresnel lens by appropriately arranging mirrors and swinging them to the proper slant angles with respect to the orientation of sunlight. The computer simulation results show that power concentration efficiency over 90%, as compared with the efficiency of directly normal incident sunlight, can be achieved with the mirror reflectance of 0.97 and for any solar incident angle within +/-75 degrees to the normal of the Fresnel lens. To verify the feasibility and performance of the concentrator with the proposed shutter, a sunlight illumination system based on this novel structure is demonstrated. Both computer simulation and practical measurement results for the prototype of the sunlight illumination system are also given to compare with. The results prove the simple and high efficient shutter applicable to general PV or sunlight-illumination systems for solar tracking.

  13. Base-load solar thermal power using thermochemical energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Luzzi, A.; Lovegrove, K. [Australian National Univ., Canberra, ACT (Australia); Filippi, E. [Ammonia Casale, Lugano (Switzerland); Fricker, H. [FC Consulting, Rickenbach (Switzerland); Schmitz-Goeb, M. [L and C Steinmuller GmbH, Process Engineering Div., Gummersbach (Germany); Chandapillai, M. [Siemens Power Generation Asia Pacific Sdn, Bhd., Industrial Power Plants, Kuala Lumpur (Malaysia)

    1999-03-01

    Using a closed-loop thermochemical system based on the reversible ammonia reaction is one of the possible ways for building solar thermal power systems capable of providing electricity on a 24-hour basis without the need for any fossil fuel back-up. In a collaborative effort between industrial and academic partners from Australia, Switzerland, Germany and Malaysia, a study was undertaken to examine the techno-economic viability of this solar concept by formulating a preliminary design for a hypothetical 10 MW{sub e} demonstration system in Central Australia. It was found that a carefully designed demonstration solar power plant, which dominantly uses proven and standard materials, components and technologies, is likely to cost of the order of AUD 157 million and operate with a net solar-to-electric conversion efficiency of 18% and a capacity factor of 80%. This will result in leveled electricity costs (LEC) of about AUD 0.24 per kWh{sub e}. (authors)

  14. Online educative activities for solar ultraviolet radiation based on measurements of cloud amount and solar exposures.

    Science.gov (United States)

    Parisi, A V; Downs, N; Turner, J; Amar, A

    2016-09-01

    A set of online activities for children and the community that are based on an integrated real-time solar UV and cloud measurement system are described. These activities use the functionality of the internet to provide an educative tool for school children and the public on the influence of cloud and the angle of the sun above the horizon on the global erythemal UV or sunburning UV, the diffuse erythemal UV, the global UVA (320-400nm) and the vitamin D effective UV. Additionally, the units of UV exposure and UV irradiance are investigated, along with the meaning and calculation of the UV index (UVI). This research will help ensure that children and the general public are better informed about sun safety by improving their personal understanding of the daily and the atmospheric factors that influence solar UV radiation and the solar UV exposures of the various wavebands in the natural environment. The activities may correct common misconceptions of children and the public about UV irradiances and exposure, utilising the widespread reach of the internet to increase the public's awareness of the factors influencing UV irradiances and exposures in order to provide clear information for minimizing UV exposure, while maintaining healthy, outdoor lifestyles.

  15. Theoretical study of solar combisystems based on bikini tanks and tank-in-tank stores

    DEFF Research Database (Denmark)

    Yazdanshenas, Eshagh; Furbo, Simon

    2012-01-01

    Purpose - Low flow bikini solar combisystems and high flow tank-in-tank solar combisystems have been studied theoretically. The aim of the paper is to study which of these two solar combisystem designs is suitable for different houses. The thermal performance of solar combisystems based on the two...... different heat storage types is compared. Design/methodology/approach - The thermal performance of Low flow bikini solar combisystems and high flow tank-in-tank solar combisystems is calculated with the simulation program TRNSYS. Two different TRNSYS models based on measurements were developed and used....... Findings - Based on the calculations it is concluded that low flow solar combisystems based on bikini tanks are promising for low energy buildings, while solar combisystems based on tank-in-tank stores are attractive for the houses with medium heating demand and old houses with high heating demand...

  16. High Performance InGaN-Based Solar Cells

    Science.gov (United States)

    2012-05-12

    electric field for an AlGaAs /GaAs MQW with 9.5 nm GaAs QWs (right). Regardless of the physical origin of the above observations, there was a clear...morphology, contact resistance, and carrier extraction; investigating the properties of solar cells grown by NH3-based molecular beam epitaxy (MBE); measuring...device performance are also discussed. Building on these advances, the unique thermal properties of high indium content multiple quantum well (MQW

  17. Control over the preferred orientation of CIGS films deposited by magnetron sputtering using a wetting layer

    Science.gov (United States)

    Yan, Yong; Jiang, Fan; Liu, Lian; Yu, Zhou; Zhang, Yong; Zhao, Yong

    2016-01-01

    A growth method is presented to control the preferred orientation in chalcopyrite CuIn x Ga1- x Se2 (CIGS) thin films grown by magnetron sputtering. Films with (220/204) and (112) preferred orientation as well as randomly oriented films were prepared. The effects of an In2Se3 wetting layer and the working pressure on the texture transition phenomena were examined. A large-grained CIGS film with (220/204) texture was formed at 400°C with the inclusion of a thin (80 nm) In2Se3 layer and liquid phase (excess copper selenide phase) formation, and the reaction mechanism is proposed. The device deposited at 2.0 Pa on an In2Se3 layer exhibited the optimal electrical properties. [Figure not available: see fulltext.

  18. Chemistry in isolation: High CCH/HCO+ line ratio in the AMIGA galaxy CIG 638

    CERN Document Server

    Martin, S; Aladro, R; Espada, D; Argudo-Fernandez, M; Kramer, C; Scott, T C

    2014-01-01

    Multi-molecule observations towards an increasing variety of galaxies have been showing that the relative molecular abundances are affected by the type of activity. However, these studies are biased towards bright active galaxies, which are typically in interaction. We study the molecular composition of one of the most isolated galaxies in the local Universe where the physical and chemical properties of their molecular clouds have been determined by intrinsic mechanisms. We present 3 mm broad band observations of the galaxy CIG 638, extracted from the AMIGA sample of isolated galaxies. The emission of the J=1-0 transitions of CCH, HCN, HCO+, and HNC are detected. Integrated intensity ratios between these line are compared with similar observations from the literature towards active galaxies including starburst galaxies (SB), active galactic nuclei (AGN), luminous infrared galaxies (LIRG), and GMCs in M33. A significantly high ratio of CCH with respect to HCN, HCO+, and HNC is found towards CIG 638 when compar...

  19. Effects of residual copper selenide on CuInGaSe 2 solar cells

    Science.gov (United States)

    Hsieh, Tung-Po; Chuang, Chia-Chih; Wu, Chung-Shin; Chang, Jen-Chuan; Guo, Jhe-Wei; Chen, Wei-Chien

    2011-02-01

    Large-grain, copper-poor CuInGaSe2 (CIGS) films are favored in the fabrication of highly efficient solar cells. However, the degradation of cell performance caused by residual copper selenide (Cu2-xSe) remains a problem. This work studies the formation and behavior of excess CuxSe and further compares the cell performance of typical copper-poor with that of copper-rich solar cells. Since excess Cu2-xSe cannot be exhausted during the growth, it fully surrounds the polycrystalline CIGS grains. Excess Cu2-xSe in the CIGS film produces serious shunt paths and causes the pn junction to be of poor quality. A short circuit in copper-rich CIGS solar cells is attributable to the conductive Cu2-xSe. The best way to ensure high-efficiency of the cells is to exhaust Cu2-xSe during growth. Otherwise, a dense, chemically treated CIGS film is required to prevent the negative effects of excess Cu2-xSe.

  20. Ground-based monitoring of solar radiation in Moldova

    Science.gov (United States)

    Aculinin, Alexandr; Smicov, Vladimir

    2010-05-01

    Integrated measurements of solar radiation in Kishinev, Moldova have been started by Atmospheric Research Group (ARG) at the Institute of Applied Physics from 2003. Direct, diffuse and total components of solar and atmospheric long-wave radiation are measured by using of the radiometric complex at the ground-based solar radiation monitoring station. Measurements are fulfilled at the stationary and moving platforms equipped with the set of 9 broadband solar radiation sensors overlapping wavelength range from UV-B to IR. Detailed description of the station can be found at the site http://arg.phys.asm.md. Ground station is placed in an urban environment of Kishinev city (47.00N; 28.56E). Summary of observation data acquired at the station in the course of short-term period from 2004 to 2009 are presented below. Solar radiation measurements were fulfilled by using CM11(280-3000 nm) and CH1 sensors (Kipp&Zonen). In the course of a year maximum and minimum of monthly sums of total radiation was ~706.4 MJm-2 in June and ~82.1MJm-2 in December, respectively. Monthly sums of direct solar radiation (on horizontal plane) show the maximum and minimum values of the order ~456.9 MJm-2 in July and ~25.5MJm-2 in December, respectively. In an average, within a year should be marked the predominance of direct radiation over the scattered radiation, 51% and 49%, respectively. In the course of a year, the percentage contribution of the direct radiation into the total radiation is ~55-65% from May to September. In the remaining months, the percentage contribution decreases and takes the minimum value of ~ 28% in December. In an average, annual sum of total solar radiation is ~4679.9 MJm-2. For the period from April to September accounts for ~76% of the annual amount of total radiation. Annual sum of sunshine duration accounts for ~2149 hours, which is of ~ 48% from the possible sunshine duration. In an average, within a year maximum and minimum of sunshine duration is ~ 304 hours in

  1. Fabrication of CIGS thin films by using spray pyrolysis and post-selenization

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seong Yeon; Kim, Jun Ho [University of Incheon, Incheon (Korea, Republic of)

    2012-06-15

    We fabricated Cu(In{sub 1-x}Ga{sub x})Se{sub 2} (x: 0 ∼ 0.4) thin films by using ultrasonic spray pyrolysis and post-selenization. First, we made Cu(In{sub 1-x}Ga{sub x})S{sub 2} (x: 0 ∼ 0.4) films by ultrasonic spray pyrolysis under an air environment. Then, we converted as-sprayed Cu(In{sub 1-x}Ga{sub x})S{sub 2} (CIGS) films to Cu(In{sub 1-x}Ga{sub x})Se{sub 2} (CIGSe) films through post-selenization. For all Ga fractions, the sprayed CIGS films were well recrystallized into poly-crystalline CIGSe films with a dominant (112) texture, which was confirmed by X-ray diffraction, Raman spectroscopy and energy dispersive X-ray analyses. This result indicates that CIGSe films with any amount of Ga substitution can be made by converting sprayed CIGS to CIGSe with post-selenization.

  2. MPPT CONTROLLER BASED SOLAR POWER GENERATION USING A MULTILEVEL INVERTER

    Directory of Open Access Journals (Sweden)

    Kelam Bhargav

    2016-02-01

    Full Text Available Solar energy is a renewable energy that is found abundantly in nature. It is green energy that can be utilized throughout day, therefore maximum energy has to captured from the panel. MPPT algorithm is incorporated to capture maximum energy. A multilevel inverter is a power electronic converter that synthesizes a desired output voltage from several levels of dc voltages of dc voltages as inputs. With an increasing number of dc voltage source, the sinusoidal waveform is obtained by the output voltage, while using a fundamental frequency-switching scheme. The advantage of multilevel inverter is very small output voltage, results in higher output quality and lower switching losses. This paper proposes a MPPT controller based solar power generation system, which consist of dc/dc converter and a new nine-level inverter.

  3. Nanocomposite-Based Bulk Heterojunction Hybrid Solar Cells

    Directory of Open Access Journals (Sweden)

    Bich Phuong Nguyen

    2014-01-01

    Full Text Available Photovoltaic devices based on nanocomposites composed of conjugated polymers and inorganic nanocrystals show promise for the fabrication of low-cost third-generation thin film photovoltaics. In theory, hybrid solar cells can combine the advantages of the two classes of materials to potentially provide high power conversion efficiencies of up to 10%; however, certain limitations on the current within a hybrid solar cell must be overcome. Current limitations arise from incompatibilities among the various intradevice interfaces and the uncontrolled aggregation of nanocrystals during the step in which the nanocrystals are mixed into the polymer matrix. Both effects can lead to charge transfer and transport inefficiencies. This paper highlights potential strategies for resolving these obstacles and presents an outlook on the future directions of this field.

  4. Improved Electrodes and Electrolytes for Dye-Based Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Harry R. Allcock; Thomas E. Mallouk; Mark W. Horn

    2011-10-26

    The most important factor in limiting the stability of dye-sensitized solar cells is the use of volatile liquid solvents in the electrolytes, which causes leakage during extended operation especially at elevated temperatures. This, together with the necessary complex sealing of the cells, seriously hampers the industrial-scale manufacturing and commercialization feasibilities of DSSCs. The objective of this program was to bring about a significant improvement in the performance and longevity of dye-based solar cells leading to commercialization. This had been studied in two ways first through development of low volatility solid, gel or liquid electrolytes, second through design and fabrication of TiO2 sculptured thin film electrodes.

  5. Dye-sensitized solar cells based on purple corn sensitizers

    Energy Technology Data Exchange (ETDEWEB)

    Phinjaturus, Kawin [Materials Science and Nanotechnology Program, Faculty of Science, Khon Kaen University, Khon Kaen 40002 (Thailand); Maiaugree, Wasan [Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen 40002 (Thailand); Suriharn, Bhalang [Department of Plant Science and Agricultural Resources, Faculty of Agriculture, Khon Kaen University, Khon Kaen 40002 (Thailand); Pimanpaeng, Samuk; Amornkitbamrung, Vittaya [Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen 40002 (Thailand); Integrated Nanotechnology Research Center (INRC), Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen 40002 (Thailand); Swatsitang, Ekaphan, E-mail: ekaphan@kku.ac.th [Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen 40002 (Thailand); Integrated Nanotechnology Research Center (INRC), Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen 40002 (Thailand); Nanotec-KKU Center of Excellence on Advanced Nanomaterials for Energy Production and Storage, Khon Kaen 40002 (Thailand)

    2016-09-01

    Graphical abstract: - Highlights: • Extract from husk, cob and silk of purple corn was used as a photosensitizer in DSSC. • Effect of solvents i.e. acetone, ethanol and DI water on DSSC efficiency was studied. • The highest efficiency of 1.06% was obtained in DSSC based on acetone extraction. - Abstract: Natural dye extracted from husk, cob and silk of purple corn, were used for the first time as photosensitizers in dye sensitized solar cells (DSSCs). The dye sensitized solar cells fabrication process has been optimized in terms of solvent extraction. The resulting maximal efficiency of 1.06% was obtained from purple corn husk extracted by acetone. The ultraviolet–visible (UV–vis) spectroscopy, Fourier transform infrared spectroscopy (FTIR), electrochemical impedance spectroscopy (EIS) and incident photon-to-current efficiency (IPCE) were employed to characterize the natural dye and the DSSCs.

  6. A Novel Solar Tracker Based on Omnidirectional Computer Vision

    Directory of Open Access Journals (Sweden)

    Zakaria El Kadmiri

    2015-01-01

    Full Text Available This paper presents a novel solar tracker system based on omnidirectional vision technology. The analysis of acquired images with a catadioptric camera allows extracting accurate information about the sun position toward both elevation and azimuth. The main advantages of this system are its wide field of tracking of 360° horizontally and 200° vertically. The system has the ability to track the sun in real time independently of the spatiotemporal coordinates of the site. The extracted information is used to control the two DC motors of the dual-axis mechanism to achieve the optimal orientation of the photovoltaic panels with the aim of increasing the power generation. Several experimental studies have been conducted and the obtained results confirm the power generation efficiency of the proposed solar tracker.

  7. In orbit debris-detection based on solar panels

    Science.gov (United States)

    Bauer, Waldemar; Romberg, Oliver; Pissarskoi, Alexei; Wiedemann, Carsten; Vörsmann, Peter

    2013-09-01

    The solar generator-based space debris impact detector (SOLID), currently under development at DLR, has a large impact area and offers high orbital flexibility. Once placed in orbit, it will collect space debris and micro-meteoroids impact data for software validation (e.g. MASTER or ORDEM). The verification of SOLID itself will be based on hypervelocity-impact testing (HVI-testing), anticipated to be performed at the Fraunhofer EMI (Ernst-Mach-Institute for High-Speed Dynamics in Freiburg, Germany). This paper presents the current state of SOLID development. Furthermore, the setup of the engineering model as well as corresponding assumptions in the manufacturing process is presented.

  8. Raster-Based Approach to Solar Pressure Modeling

    Science.gov (United States)

    Wright, Theodore W. II

    2013-01-01

    shown on the computer screen is composed of up to millions of pixels. Each of those pixels is associated with a small illuminated area of the spacecraft. For each pixel, it is possible to compute its position, angle (surface normal) from the view direction, and the spacecraft material (and therefore, optical coefficients) associated with that area. With this information, the area associated with each pixel can be modeled as a simple flat plate for calculating solar pressure. The vector sum of these individual flat plate models is a high-fidelity approximation of the solar pressure forces and torques on the whole vehicle. In addition to using optical coefficients associated with each spacecraft material to calculate solar pressure, a power generation coefficient is added for computing solar array power generation from the sum of the illuminated areas. Similarly, other area-based calculations, such as free molecular flow drag, are also enabled. Because the model rendering is separated from other calculations, it is relatively easy to add a new model to explore a new vehicle or mission configuration. Adding a new model is performed by adding OpenGL code, but a future version might read a mesh file exported from a computer-aided design (CAD) system to enable very rapid turnaround for new designs

  9. Satellite-advection based solar forecasting: lessons learned and progress towards probabalistic solar forecasting

    Science.gov (United States)

    Rogers, M. A.

    2015-12-01

    Using satellite observations from GOES-E and GOES-W platforms in concert with GFS-derived cloud-level winds and a standalone radiative transfer model, an advection-derived forecast for surface GHI over the continental United States, with intercomparison between forecasts for four zones over the CONUS and Central Pacific with SURFRAD results. Primary sources for error in advection-based forecasts, primarily driven by false- or mistimed ramp events are discussed, with identification of error sources quantified along with techniques used to improve advection-based forecasts to approximately 10% MAE for designated surface locations. Development of a blended steering wind product utilizing NWP output combined with satellite-derived winds from AMV techniques to improve 0-1 hour advection forecasts will be discussed. Additionally, the use of two years' of solar forecast observations in the development of a prototype probablistic forecast for ramp events will be shown, with the intent of increasing the use of satellite-derived forecasts for grid operators and optimizing integration of renewable resources into the power grid. Elements of the work were developed under the 'Public-Private-Academic Partnership to Advance Solar Power Forecasting' project spearheaded by the National Center for Atmospheric Research.

  10. EFRC: Polymer-Based Materials for Harvesting Solar Energy (stimulus)"

    Energy Technology Data Exchange (ETDEWEB)

    Russell, Thomas P. [Univ. of Massachusetts, Amherst, MA (United States)

    2016-12-08

    The University of Massachusetts Amherst is proposing an Energy Frontier Research Center (EFRC) on Polymer-Based Materials for Harvesting Solar Energy that will integrate the widely complementary experimental and theoretical expertise of 23 faculty at UMass-Amherst Departments with researchers from the University of Massachusetts Lowell, University of Pittsburgh, the Pennsylvania State University and Konarka Technologies, Inc. Collaborative efforts with researchers at the Oak Ridge National Laboratory, the University of Bayreuth, Seoul National University and Tohoku University will complement and expand the experimental efforts in the EFRC. Our primary research aim of this EFRC is the development of hybrid polymer-based devices with efficiencies more than twice the current organic-based devices, by combining expertise in the design and synthesis of photoactive polymers, the control and guidance of polymer-based assemblies, leadership in nanostructured polymeric materials, and the theory and modeling of non-equilibrium structures. A primary goal of this EFRC is to improve the collection and conversion efficiency of a broader spectral range of solar energy using the directed self-assembly of polymer-based materials so as to optimize the design and fabrication of inexpensive devices.

  11. The effect of silicon and copper-indium-gallium-selenide based solar cell structures and processing on temperature dependent performance losses

    Science.gov (United States)

    Hsieh, Judith

    Temperature dependent current voltage measurements (J-V-T) of solar cells. provide both fundamental and practical information. They give detailed insight into. recombination losses within the device as well as information about module. performance losses at higher outdoor operating temperatures. In this thesis, J-V-T. measurements were applied to two distinctly different types of solar cells: crystalline. silicon heterojunction cells and thin film (AgCu)(InGa)Se2 or ACIGS polycrystalline. cells. Crystalline silicon solar cells with heterojunction structure improve the opencircuit. voltage and efficiency. Interdigitated back contact (IBC) Si solar cells obtain a. higher short-circuit current and fill factor compared to front heterojunction (FHJ) solar. cells. ACIGS solar cells have shown higher efficiencies at wider bandgap compared to. the baseline CIGS solar cells. Two high open-circuit voltage CIGS solar cells are. included and compared with ACIGS solar cells. In this thesis, the impact of different. types of solar cells structure and fabrication on temperature dependent performance. losses will be discussed. Devices with higher bandgap are predicted to have higher. open-circuit voltage and lower temperature coefficient of maximum power output. (Pmax). The correlation between temperature coefficient of Pmax and open-circuit. voltage can be found in Si FHJ cells but not Si IBC or ACIGS cells. However, ACIGS. cells show an inverse correlation between temperature coefficient of Pmax and bandgap. as expected. Analysis of diode quality factor and other parameters are interpreted. Sshape. J-V curve can reduce the device's fill factor with a relative high series resistance. This phenomenon tends to occur in FHJ cells rather than IBC at low temperature. Light-dark crossover and roll over effects are commonly seen in ACIGS cells and the. anomaly is enhanced at lower temperature. Most of FHJ and IBC cells obtain the. ideality factor between 1 and 2 while some of ACIGS

  12. High-Efficiency Flexible Solar Cells Based on Organometal Halide Perovskites.

    Science.gov (United States)

    Wang, Yuming; Bai, Sai; Cheng, Lu; Wang, Nana; Wang, Jianpu; Gao, Feng; Huang, Wei

    2016-06-01

    Flexible and light-weight solar cells are important because they not only supply power to wearable and portable devices, but also reduce the transportation and installation cost of solar panels. High-efficiency organometal halide perovskite solar cells can be fabricated by a low-temperature solution process, and hence are promising for flexible-solar-cell applications. Here, the development of perovskite solar cells is briefly discussed, followed by the merits of organometal halide perovskites as promising candidates as high-efficiency, flexible, and light-weight photovoltaic materials. Afterward, recent developments of flexible solar cells based on perovskites are reviewed.

  13. Solar ponds. Citations from the NTIS data base

    Science.gov (United States)

    Hundemann, A. S.

    1980-08-01

    Federally funded research on the design, performance, and use of solar ponds is discussed on these. Topic areas cover the use of solar ponds in industrial process heat production, roof ponds for passive solar buildings, and solar ponds use in the production of biomass for renewable fuels.

  14. Project SunSHINE: A Student Based Solar Research Program

    Science.gov (United States)

    Donahue, R.

    2000-12-01

    Eastchester Middle School (NY) is currently conducting an ongoing, interdisciplinary solar research program entitled Project SunSHINE, for Students Help Investigate Nature in Eastchester. Students are to determine how ultraviolet and visible light levels vary throughout the year at the school's geographic location, and to ascertain if any measured variations correlate to daily weather conditions or sunspot activity. The educational goal is to provide students the opportunity to conduct original and meaningful scientific research, while learning to work collaboratively with peers and teachers in accordance with national mathematics, science and technology standards. Project SunSHINE requires the student researchers to employ a number of technologies to collect and analyze data, including light sensors, astronomical imaging software, an onsite AirWatch Weather Station, Internet access to retrieve daily solar images from the National Solar Observatory's Kitt Peak Vacuum Telescope, and two wide field telescopes for live sunspot observations. The program has been integrated into the science, mathematics, health and computer technology classes. Solar and weather datasets are emailed weekly to physicist Dr. Gil Yanow of the Jet Propulsion Laboratory for inclusion in his global study of light levels. Dr. Yanow credited the Project SunSHINE student researchers last year for the discovery of an inverse relationship between relative humidity and ultraviolet light levels. The Journal News Golden Apple Awards named Project SunSHINE the 1999 New York Wired Applied Technology Award winner. This honor recognizes the year's outstanding educational technology program at both the elementary and secondary level, and included a grant of \\$20,000 to the research program. Teacher training and image processing software for Project SunSHINE has been supplied by The Use of Astronomy in Research Based Science Education (RBSE), a Teacher Enhancement Program funded by the National Science

  15. Development of a Greek solar map based on solar model estimations

    Science.gov (United States)

    Kambezidis, H. D.; Psiloglou, B. E.; Kavadias, K. A.; Paliatsos, A. G.; Bartzokas, A.

    2016-05-01

    The realization of Renewable Energy Sources (RES) for power generation as the only environmentally friendly solution, moved solar systems to the forefront of the energy market in the last decade. The capacity of the solar power doubles almost every two years in many European countries, including Greece. This rise has brought the need for reliable predictions of meteorological data that can easily be utilized for proper RES-site allocation. The absence of solar measurements has, therefore, raised the demand for deploying a suitable model in order to create a solar map. The generation of a solar map for Greece, could provide solid foundations on the prediction of the energy production of a solar power plant that is installed in the area, by providing an estimation of the solar energy acquired at each longitude and latitude of the map. In the present work, the well-known Meteorological Radiation Model (MRM), a broadband solar radiation model, is engaged. This model utilizes common meteorological data, such as air temperature, relative humidity, barometric pressure and sunshine duration, in order to calculate solar radiation through MRM for areas where such data are not available. Hourly values of the above meteorological parameters are acquired from 39 meteorological stations, evenly dispersed around Greece; hourly values of solar radiation are calculated from MRM. Then, by using an integrated spatial interpolation method, a Greek solar energy map is generated, providing annual solar energy values all over Greece.

  16. LiDAR-Based Solar Mapping for Distributed Solar Plant Design and Grid Integration in San Antonio, Texas

    Directory of Open Access Journals (Sweden)

    Tuan B. Le

    2016-03-01

    Full Text Available This study represents advancements in the state-of-the-art of the solar energy industry by leveraging LiDAR-based building characterization for city-wide, distributed solar photovoltaics, solar maps, highlighting the distribution of solar energy across the city of San Antonio. A methodology is implemented to systematically derive the tilt and azimuth angles of each rooftop and to quantify solar direct, diffuse, and global horizontal irradiance for hundreds of buildings in a LiDAR tile scale, by using already established methodologies that are typically only applied to a single location or building rooftop. The methodology enables the formulation of typical meteorological data, measured or forecasted time series of irradiances over distributed assets. A new concept on the subject of distributed solar plant (DSP design is also introduced, by using the building rooftop tilt and azimuth angles, to strategically optimize the use and adoption of solar incentives according to the grid age and its vulnerabilities to solar variability in the neighborhoods. The method presented here shows that on an hourly basis DSP design could provide a 5% and 9% of net load capacity support per hour in the afternoon and morning times, respectively. Our results show that standard building rooftop tilt angles in the south Texas region has significant impact on the total amount of the energy over the course of a day, though its impact on the shapes of the daily energy profile is relatively insignificant when compared to the azimuth angle. Building surfaces’ azimuth angle is the most important factor to determine the shape of daily energy profile and its peak location within a day. The methodology developed in this study can be employed to study the potential solar energy in other regions and to match the design of distributed solar plants to the capacity needs on specified distribution grids.

  17. Zinc-oxide-based nanostructured materials for heterostructure solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Bobkov, A. A.; Maximov, A. I.; Moshnikov, V. A., E-mail: vamoshnikov@mail.ru; Somov, P. A.; Terukov, E. I. [St. Petersburg Electrotechnical University LETI (Russian Federation)

    2015-10-15

    Results obtained in the deposition of nanostructured zinc-oxide layers by hydrothermal synthesis as the basic method are presented. The possibility of controlling the structure and morphology of the layers is demonstrated. The important role of the procedure employed to form the nucleating layer is noted. The faceted hexagonal nanoprisms obtained are promising for the fabrication of solar cells based on oxide heterostructures, and aluminum-doped zinc-oxide layers with petal morphology, for the deposition of an antireflection layer. The results are compatible and promising for application in flexible electronics.

  18. ZnO nanotube based dye-sensitized solar cells.

    Energy Technology Data Exchange (ETDEWEB)

    Martinson, A. B. F.; Elam, J. W.; Hupp, J. T.; Pellin, M. J. (Materials Science Division); (Northwestern Univ.)

    2007-05-25

    We introduce high surface area ZnO nanotube photoanodes templated by anodic aluminum oxide for use in dye-sensitized solar cells (DSSCs). Atomic layer deposition is utilized to coat pores conformally, providing a direct path for charge collection over tens of micrometers thickness. Compared to similar ZnO-based devices, ZnO nanotube cells show exceptional photovoltage and fill factors, in addition to power efficiencies up to 1.6%. The novel fabrication technique provides a facile, metal-oxide general route to well-defined DSSC photoanodes.

  19. ZnO nanotube based dye-sensitized solar cells.

    Science.gov (United States)

    Martinson, Alex B F; Elam, Jeffrey W; Hupp, Joseph T; Pellin, Michael J

    2007-08-01

    We introduce high surface area ZnO nanotube photoanodes templated by anodic aluminum oxide for use in dye-sensitized solar cells (DSSCs). Atomic layer deposition is utilized to coat pores conformally, providing a direct path for charge collection over tens of micrometers thickness. Compared to similar ZnO-based devices, ZnO nanotube cells show exceptional photovoltage and fill factors, in addition to power efficiencies up to 1.6%. The novel fabrication technique provides a facile, metal-oxide general route to well-defined DSSC photoanodes.

  20. Hydrogen based energy storage for solar energy systems

    Energy Technology Data Exchange (ETDEWEB)

    Vanhanen, J.P.; Hagstroem, M.T.; Lund, P.H. [Helsinki Univ. of Technology, Otaniemi (Finland). Dept. of Engineering Physics and Mathematics; Leppaenen, J.R.; Nieminen, J.P. [Neste Oy (Finland)

    1998-12-31

    Hydrogen based energy storage options for solar energy systems was studied in order to improve their overall performance. A 1 kW photovoltaic hydrogen (PV-H2) pilot-plant and commercial prototype were constructed and a numerical simulation program H2PHOTO for system design and optimisation was developed. Furthermore, a comprehensive understanding of conversion (electrolysers and fuel cells) and storage (metal hydrides) technologies was acquired by the project partners. The PV-H{sub 2} power system provides a self-sufficient solution for applications in remote locations far from electric grids and maintenance services. (orig.)

  1. Roles of Ground-based Solar Observations of Hida Observatory toward the Solar-C Era

    Science.gov (United States)

    Ueno, S.; Shibata, K.; Ichimoto, K.; Nagata, S.; Dorotovič, I.; Shahamatnia, E.; Ribeiro, R. A.; Fonseca, J. M.

    2016-04-01

    For the realization of the Solar-C satellite, discussions about scientific themes and preliminary observations are internationally carried out now. At Hida Observatory of Kyoto University, we will play the following roles toward the Solar-C era by utilizing the Domeless Solar Telescope (DST) and the international solar chromospherirc full-disk observation network (CHAIN project) that includes the Solar Magnetic Activity Research Telescope (SMART) with international collaborations, for example, such as the development of image-analysis software by UNINOVA (Portugal) and so on.

  2. Vertical InGaN-based green-band solar cells operating under high solar concentration up to 300 suns.

    Science.gov (United States)

    Sheu, Jinn-Kong; Chen, Fu-Bang; Wu, Shou-Hung; Lee, Ming-Lun; Chen, Po-Cheng; Yeh, Yu-Hsiang

    2014-08-25

    InGaN/GaN-based solar cells with vertical-conduction feature on silicon substrates were fabricated by wafer bonding technique. The vertical solar cells with a metal reflector sandwiched between the GaN-based epitaxial layers and the Si substrate could increase the effective thickness of the absorption layer. Given that the thermally resistive sapphire substrates were replaced by the Si substrate with high thermal conductivity, the solar cells did not show degradation in power conversion efficiency (PCE) even when the solar concentrations were increased to 300 suns. The open circuit voltage increased from 1.90 V to 2.15 V and the fill factor increased from 0.55 to 0.58 when the concentrations were increased from 1 sun to 300 suns. With the 300-sun illumination, the PCE was enhanced by approximately 33% compared with the 1-sun illumination.

  3. 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

  4. Matemáticas y literatura de 0 a 3: Un cuento de cigüeñas

    Directory of Open Access Journals (Sweden)

    Gonzalo Flecha López

    2014-12-01

    Full Text Available A partir de los elementos del entorno próximo, tanto físico como cultural, podemos abordar conceptos matemáticos relacionados con la clasificación y con la formación de conjuntos. Utilizando como punto de partida los cuentos “El libro del otoño” y “Un cuento de cigüeñas”, vamos a tratar de realizar clasificaciones utilizando como base la formación de conceptos. Realizaremos, con los niños, agrupamientos sencillos mediante relaciones equivalencia. Mathematics and literature from zero to three: A tale of storks. From the elements of the surrounding environment both physical and cultural, we can deal with mathematical concepts related to classification and formation of sets. Using as a starting point the reading of “The book of autumn” and “A tale of storks”, we will try to make classifications using as base concept formation. We will make, with children, simple groupings using equivalence relations.

  5. Design, construction, and implementation of a ground-based solar spectrograph for the National Student Solar Spectrograph Competition

    Science.gov (United States)

    Keeler, E.; Moen, D.; Peck, C.; Zimny, C.; Repasky, K.

    2012-10-01

    A solar spectrograph is an instrument that takes incoming sunlight over a specified portion of the sun's emitted electromagnetic spectrum and separates the light into its constituent frequency components, or spectrum. The components are then sent to a detector that measures intensity, which reveals the location of spectral properties of the light such as absorption and emission lines. The National Student Solar Spectrograph Competition (NSSSC) is a Montana Space Grant Consortium sponsored competition where undergraduate student teams from across the country design, build, and implement a ground-based solar spectrograph to perform any solar related task and demonstrate their spectrographs for the competition in May 2012 in Bozeman, MT. Each team is given a 2,000-dollar budget to build their spectrograph, which cannot be exceeded, and all spectrographs must follow regulations in the NSSSC guidelines. This team designed a spectrograph to be capable of imaging the sun across the visible spectrum using spatial filters and a standard photo detector rather than a traditional charge-coupled device due to budget limitations. The spectrograph analyzes the spectrum of small sections of the sun to determine how the spectrum varies across solar features such as the corona, active regions, and quiet regions. In addition to solar imaging, the spectrograph will also analyze atmospheric absorption of the solar spectrum by comparing the measured spectrum to the theoretical spectrum calculated from the blackbody equation.

  6. Modeling and Simulation of a Dual-Junction CIGS Solar Cell Using Silvaco ATLAS

    Science.gov (United States)

    2012-12-01

    Development. 15. NUMBER OF PAGES 118 16. PRICE CODE 17. SECURITY CLASSIFICATION OF REPORT Unclassified 18. SECURITY CLASSIFICATION OF THIS...PAGE Unclassified 19. SECURITY CLASSIFICATION OF ABSTRACT Unclassified 20. LIMITATION OF ABSTRACT UU NSN 7540–01–280–5500 Standard Form...Pulsed Laser Deposition PV Photovoltaic PVD Physical Vapor

  7. Expanding thermal plasma chemical vapour deposition of ZnO:Al layers for CIGS solar cells

    NARCIS (Netherlands)

    Sharma, K.; Williams, B.L.; Mittal, A.; Knoops, H.C.M.; Kniknie, B.J.; Bakker, N.J.; Kessels, W.M.M.; Schropp, R.E.I.; Creatore, M.

    2014-01-01

    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

  8. 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.

  9. Adaptive control for solar energy based DC microgrid system development

    Science.gov (United States)

    Zhang, Qinhao

    During the upgrading of current electric power grid, it is expected to develop smarter, more robust and more reliable power systems integrated with distributed generations. To realize these objectives, traditional control techniques are no longer effective in either stabilizing systems or delivering optimal and robust performances. Therefore, development of advanced control methods has received increasing attention in power engineering. This work addresses two specific problems in the control of solar panel based microgrid systems. First, a new control scheme is proposed for the microgrid systems to achieve optimal energy conversion ratio in the solar panels. The control system can optimize the efficiency of the maximum power point tracking (MPPT) algorithm by implementing two layers of adaptive control. Such a hierarchical control architecture has greatly improved the system performance, which is validated through both mathematical analysis and computer simulation. Second, in the development of the microgrid transmission system, the issues related to the tele-communication delay and constant power load (CPL)'s negative incremental impedance are investigated. A reference model based method is proposed for pole and zero placements that address the challenges of the time delay and CPL in closed-loop control. The effectiveness of the proposed modeling and control design methods are demonstrated in a simulation testbed. Practical aspects of the proposed methods for general microgrid systems are also discussed.

  10. Highly efficient vacuum processed BHJ solar cell based on merocyanines

    Energy Technology Data Exchange (ETDEWEB)

    Steinmann, Vera; Kronenberg, Nils M.; Lenze, Martin R.; Hertel, Dirk; Meerholz, Klaus [Department fuer Chemie, Universitaet Koeln (Germany); Buerckstuemmer, Hannah; Wuerthner, Frank [Institut fuer Organische Chemie, Roentgen Research Center for Complex Material Systems, Universitaet Wuerzburg (Germany)

    2011-07-01

    Bulk heterojunction (BHJ) organic solar cells have attracted considerable interest due to their potential for large-scale, cost-effective and environmentally friendly power generation. Small molecules have been successfully introduced in solution- (SOL) as well as vacuum- (VAC) processed devices, reporting efficiencies (PCE) up to 4.4% and 5.7% respectively. For simple layer stack devices (2-3 layers) based on CuPc as electron donor and C{sub 60} as electron acceptor PCEs up to 5.0% have been achieved. Recently, we presented a direct comparison of highly efficient SOL and VAC BHJ cells based on merocyanine dyes (MC) with a similarly simple layer stack as reported in the literature. Our most efficient devices exhibited PCEs up to 4.9%. Further optimizations on the VAC processed cells led to high PCEs exceeding 6% while keeping the same simple layer stack. In addition, these cells have demonstrated exceptional performance even at lower light intensities. Due to the simple chemical variability of MC dyes, they are ideally suited for tandem solar cells. We present first attempts in this direction.

  11. Carbon nanotube-based heterostructures for solar energy applications.

    Science.gov (United States)

    Wang, Lei; Liu, Haiqing; Konik, Robert M; Misewich, James A; Wong, Stanislaus S

    2013-10-21

    One means of combining the unique physical and chemical properties of both carbon nanotubes and complementary material motifs (such as metal sulfide quantum dots (QDs), metal oxide nanostructures, and polymers) can be achieved by generating carbon nanotube (CNT)-based heterostructures. These materials can be subsequently utilized as novel and interesting constituent building blocks for the assembly of functional light energy harvesting devices and because of their architectural and functional flexibility, can potentially open up novel means of using and taking advantage of existing renewable energy sources. In this review, we present the reliable and reproducible synthesis of several unique model CNT-based heterostructured systems as well as include an accompanying discussion about the charge transfer and energy flow properties of these materials for their potential incorporation into a range of practical solar energy conversion devices.

  12. Multifunctional Solar Systems Based On Two-Stage Regeneration Absorbent Solution

    Directory of Open Access Journals (Sweden)

    Doroshenko A.V.

    2015-04-01

    Full Text Available The concepts of multifunctional dehumidification solar systems, heat supply, cooling, and air conditioning based on the open absorption cycle with direct absorbent regeneration developed. The solar systems based on preliminary drainage of current of air and subsequent evaporated cooling. The solar system using evaporative coolers both types (direct and indirect. The principle of two-stage regeneration of absorbent used in the solar systems, it used as the basis of liquid and gas-liquid solar collectors. The main principle solutions are designed for the new generation of gas-liquid solar collectors. Analysis of the heat losses in the gas-liquid solar collectors, due to the mechanism of convection and radiation is made. Optimal cost of gas and liquid, as well as the basic dimensions and configuration of the working channel of the solar collector identified. Heat and mass transfer devices, belonging to the evaporative cooling system based on the interaction between the film and the gas stream and the liquid therein. Multichannel structure of the polymeric materials used to create the tip. Evaporative coolers of water and air both types (direct and indirect are used in the cooling of the solar systems. Preliminary analysis of the possibilities of multifunctional solar absorption systems made reference to problems of cooling media and air conditioning on the basis of experimental data the authors. Designed solar systems feature low power consumption and environmental friendliness.

  13. Study of solar active regions based on BOAO vector magnetograms

    CERN Document Server

    Moon, Y J; Yun, H S; Cho, E A

    1999-01-01

    In this study we present the study of solar active regions based on BOAO vector magnetograms and $H\\alpha$ filtergrams. With the new calibration method we analyzed BOAO vector magnetograms taken from the SOFT observational system to compare with those of other observing systems. In this study it has been demonstrated that (1) our longitudinal magnetogram matches very well the corresponding Mitaka's magnetogram to the extent that the maximum correlation yields r=0.962 between our re-scaled longitudinal magnetogram and the Mitaka's magnetogram; (2) according to a comparison of our magnetograms of AR 8422 with those taken at Mitaka solar observatory their longitudinal fields are very similar to each other while transverse fields are a little different possibly due to large noise level; (3) main features seen by our longitudinal magnetograms of AR 8422 and AR 8419 and the corresponding Kitt Peak magnetograms are very similar to each other; (4) time series of our vector magnetograms and H-alpha observations of AR ...

  14. A Wireless Greenhouse Monitoring System Based on Solar Energy

    Directory of Open Access Journals (Sweden)

    Liai Gao

    2013-09-01

    Full Text Available To resolve the problems of complicated cabling and costly wired network in the current system, we designed a wireless greenhouse monitoring system based on ZigBee and GSM technology.  The system consists of two parts: a wireless sensor network and remote control terminal. According to parameters distribution in the monitoring regional, a wireless transmission network was formed, all of the node in the network using solar power. In the remote control terminal, the study developed a simplified expert decision system, in which the part of greenhouse control decision adopts the fuzzy decoupling control algorithm to realize the temperature and humidity decoupling control and increase the accuracy of decision-making.According to the experimental test, the monitoring system can run well under the conditions in northern China greenhouses. It can realize real-time, accurate monitoring and collecting of parameters data in the greenhouse environment; the remote control terminal can give effective decision management solutions. Our future work will mainly be solar photovoltaic panel servo system and image transmission.      

  15. Semitransparent Polymer Solar Cells Based on Liquid Crystal Reflectors

    Directory of Open Access Journals (Sweden)

    Shaopeng Yang

    2014-01-01

    Full Text Available The effects of liquid crystal (LC reflectors on semitransparent polymer solar cells (PSCs were investigated in this paper. By improving the cathode, we manufactured semitransparent PSCs based on the conventional PSCs. We then incorporated the LC reflector into the semitransparent PSCs, which increased the power conversion efficiency (PCE from 2.11% to 2.71%. Subsequently adjusting the concentration and spinning speed of the active layer material changed its thickness. The maximum light absorption for the active layer was obtained using the optimum thickness, and the PCE eventually reached 3.01%. These results provide a reference for selecting LC reflectors that are suitable for different active layer materials to improve the PCE of semitransparent PSCs.

  16. Phototransistor Behavior Based on Dye-Sensitized Solar Cell

    CERN Document Server

    Wang, X Q; Wang, Y F; Zhou, W Q; Lu, Y M; Liu, Z Y

    2012-01-01

    In the present work, a light-controlled device cell is established based on the dye-sensitized solar cell using nanocrystalline TiO2 films. Voltage-current curves are characterized by three types of transport behaviors: linear increase, saturated plateau and breakdown-like increase, which are actually of the typical performances for a photo-gated transistor. Moreover, an asymmetric behavior is observed in the voltage-current loops, which is believed to arise from the difference in the effective photo-conducting areas. The photovoltaic voltage between the shared counter electrode and drain (VCE-D) is investigated as well, clarifying that the predominant dark process in source and the predominant photovoltaic process in drain are series connected, modifying the electric potential levels and thus resulting in the characteristic phototransistor behaviors.

  17. A review of solar energy based heat and power generation systems

    DEFF Research Database (Denmark)

    Modi, Anish; Bühler, Fabian; Andreasen, Jesper Graa

    2017-01-01

    The utilization of solar energy based technologies has attracted increased interest in recent times in order to satisfy the various energy demands of our society. This paper presents a thorough review of the open literature on solar energy based heat and power plants. In order to limit the scope....... The paper also presents a selection of case studies for the evaluation of solar energy based combined heat and power generation possibility in Denmark. The considered technologies for the case studies are (1) solar photovoltaic modules, (2) solar flat plate collectors, (3) a ground source heat pump, (4......-biomass hybrid plants for combined heat and power production in the Nordic climatic conditions. The results also suggest that the configuration with an organic Rankine cycle with solar thermal collectors and a biomass burner is particularly attractive for large capacity plants....

  18. 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)

  19. Epitaxial lift-off technology of GaAs multijunction solar cells

    Science.gov (United States)

    Knyps, P.; Dumiszewska, E.; Kaszub, W.; Przewłoka, A.; Strupinski, W.

    2016-12-01

    Epitaxial lift-off (ELO) is a process which enables the removal of solar cell structures (one junction GaAs, two junction GaAs/InGaP or three junction GaAs/InGaAs/InGaP) from the substrate on which they are grown and their transfer onto lightweight carriers such as metal or polymeric insulator films. The said solar cells exhibit superior power conversion efficiency compared with alternative single-junction photovoltaic cell designs such as those based on crystalline Si, copper indium gallium sulfide (CIGS) or CdTe. The major advantage of ELO solar cells is the potential for wafer reuse, which can enable significant manufacturing cost reduction by minimizing the consumption of expensive wafers. Here in this work we have grown one junction GaAs solar cells on GaAs (100) substrates. A 10 nm thick AlAs layer has been used as a release layer, which has been selectively etched in HF solution. We have investigated different methods of transferring thin films onto polymer and copper foils, including the usage of temporary mounting adhesives and electro-conductive pastes. Lift-off has been demonstrated to be a very promising technique for producing affordable solar cells with a very high efficiency of up to 30%.

  20. Properties of Encapsulated CIGS Cells in 85 degrees C/85%RH

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, Larry C.; Gross, Mark E.; Kundu, Sambhu N.; Shafaman, William N.

    2010-02-16

    This paper concerns studies of encapsulated cells subjected to an environment of 85ºC and 85%RH (85/85). Cells are encapsulated with PNNL multi-layer coatings (referred to as PML coatings) utilizing alternating layers of Al2O3, and an advanced polymer. The new polymer has been determined to withstand the 85/85 environment. Two types of cells were used for these studies, namely, SSI mini-modules (which are actually CIGSS devices) and CIGS cells provided by the Institute of Energy Conversion (IEC). Cells were coated and stressed at 85/85 in an environmental chamber. Current-voltage characteristics were acquired before and after coating, and periodically after being subjected to the 85/85 environment. Whereas coated SSI modules were determined to last 1000 hours when stressed at 60ºC/90%RH without degradation, the efficiency of these modules degrade to a level of 60% of the beginning-of-life value when stressed at 85/85. Encapsulated IEC cells, however, have exhibited extraordinary results. The efficiency of several encapsulated cells did not decrease for 1500 hours in an 85ºC/85%RH environment. This results establishes a benchmark for stressed, encapsulated CIGS cells.

  1. Towards cost reduction in concentrating solar power: innovative design for an efficient fresnel based solar field

    OpenAIRE

    Abbas Camara, Rubén

    2015-01-01

    Energía termosolar (de concentración) es uno de los nombres que hacen referencia en español al término inglés “concentrating solar power”. Se trata de una tecnología basada en la captura de la potencia térmica de la radiación solar, de forma que permita alcanzar temperaturas capaces de alimentar un ciclo termodinámico convencional (o avanzado); el futuro de esta tecnología depende principalmente de su capacidad para concentrar la radiación solar de manera eficiente y económica. La presente te...

  2. Effects of solar radiation on collagen-based biomaterials

    Directory of Open Access Journals (Sweden)

    Alina Sionkowska

    2006-01-01

    Full Text Available The effect of solar radiation on collagen and collagen/synthetic polymer blends in the form of thin films and solutions has been studied by UV-VIS and FTIR spectroscopies. Films and solutions of collagen blended with poly(vinyl alcohol (PVA and poly(vinyl pyrrolidone (PVP were irradiated by solar light. It was found that UV-VIS spectra, which characterize collagen, collagen/PVA, and collagen/PVP blended films, were significantly altered by solar radiation. FTIR spectra of collagen, collagen/PVA, and collagen/PVP films showed that after solar irradiation, the positions of Amide A bands were shifted to lower wavenumbers. There was not any significant alteration in the position of Amide I and Amide II bands of collagen and its blends after solar radiation. The effect of solar UV radiation in comparison with artificial UV radiation has been discussed.

  3. Ambient roll-to-roll fabrication of flexible solar cells based on small molecules

    DEFF Research Database (Denmark)

    Lin, Yuze; Dam, Henrik Friis; Andersen, Thomas Rieks;

    2013-01-01

    All solution-processed roll-to-roll flexible solar cells based on a starshaped small molecule donor and PCBMacceptor were fabricated by slot-die coating, as the first successful example reported for small molecule roll-to-roll flexible solar cells.......All solution-processed roll-to-roll flexible solar cells based on a starshaped small molecule donor and PCBMacceptor were fabricated by slot-die coating, as the first successful example reported for small molecule roll-to-roll flexible solar cells....

  4. Synthesis of Inorganic Semiconductor Materials for Solar-Based Technologies

    OpenAIRE

    2014-01-01

    There is an alarming increase of energy issues due to significant fossil fuel consumption. Some progress has been made to replace fossil fuels with renewable sources, among which, solar energy has always been considered as the ultimate solution to solve these problems. As a relatively new evolved type of solar cell, Dye-sensitized solar cells (DSSC), have been investigated intensively in recent years and they are very promising for their cost-effectiveness properties. Zinc oxide (ZnO) is one ...

  5. Determination of the Electrical Junction in Cu(In, Ga)Se2 and Cu2ZnSnSe4 Solar Cells with 20-nm Spatial Resolution

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Chuanxiao; Jiang, Chun-Sheng; Moutinho, Helio; Levi, Dean; Yan, Yanfa; Gorman, Brian; Al-Jassim, Mowafak

    2016-11-21

    We located the electrical junction (EJ) of Cu(In, Ga)Se2 (CIGS) and Cu2ZnSnSe4 (CZTS) solar cells with ~20-nm accuracy using a scanning capacitance spectroscopy (SCS) technique. A procedure was developed to prepare the cross-sectional samples and grow critical high-quality insulating layers for the SCS measurement. We found that CIGS has a buried homojunction with the EJ located at ~40 nm inside the CIGS/CdS interface. An n-type CIGS was probed in the region 10-30 nm away from the interface. By contrast, the CZTS/CdS cells have a heterointerface junction with a shallower EJ (~20 nm) than CIGS. The EJ is ~20 nm from the CZTS/CdS interface, which is consistent with asymmetrical carrier concentrations of the p-CZTS and n-CdS in a heterojunction cell. The unambiguous determination of the junction locations helped explain the large open circuit voltage difference between the state-of-the-art devices of CIGS and CZTS.

  6. 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%.

  7. Monolithic-Structured Single-Layered Textile-Based Dye-Sensitized Solar Cells

    Science.gov (United States)

    Yun, Min Ju; Cha, Seung I.; Kim, Han Seong; Seo, Seon Hee; Lee, Dong Y.

    2016-10-01

    Textile-structured solar cells are frequently discussed in the literature due to their prospective applications in wearable devices and in building integrated solar cells that utilize their flexibility, mechanical robustness, and aesthetic appearance, but the current approaches for textile-based solar cells—including the preparation of fibre-type solar cells woven into textiles—face several difficulties from high friction and tension during the weaving process. This study proposes a new structural concept and fabrication process for monolithic-structured textile-based dye-sensitized solar cells that are fabricated by a process similar to the cloth-making process, including the preparation of wires and yarns that are woven for use in textiles, printed, dyed, and packaged. The fabricated single-layered textile-based dye-sensitized solar cells successfully act as solar cells in our study, even under bending conditions. By controlling the inter-weft spacing and the number of Ti wires for the photoelectrode conductor, we have found that the performance of this type of dye-sensitized solar cell was notably affected by the spacing between photoelectrodes and counter-electrodes, the exposed areas of Ti wires to photoelectrodes, and photoelectrodes’ surface morphology. We believe that this study provides a process and concept for improved textile-based solar cells that can form the basis for further research.

  8. Monolithic-Structured Single-Layered Textile-Based Dye-Sensitized Solar Cells.

    Science.gov (United States)

    Yun, Min Ju; Cha, Seung I; Kim, Han Seong; Seo, Seon Hee; Lee, Dong Y

    2016-10-06

    Textile-structured solar cells are frequently discussed in the literature due to their prospective applications in wearable devices and in building integrated solar cells that utilize their flexibility, mechanical robustness, and aesthetic appearance, but the current approaches for textile-based solar cells-including the preparation of fibre-type solar cells woven into textiles-face several difficulties from high friction and tension during the weaving process. This study proposes a new structural concept and fabrication process for monolithic-structured textile-based dye-sensitized solar cells that are fabricated by a process similar to the cloth-making process, including the preparation of wires and yarns that are woven for use in textiles, printed, dyed, and packaged. The fabricated single-layered textile-based dye-sensitized solar cells successfully act as solar cells in our study, even under bending conditions. By controlling the inter-weft spacing and the number of Ti wires for the photoelectrode conductor, we have found that the performance of this type of dye-sensitized solar cell was notably affected by the spacing between photoelectrodes and counter-electrodes, the exposed areas of Ti wires to photoelectrodes, and photoelectrodes' surface morphology. We believe that this study provides a process and concept for improved textile-based solar cells that can form the basis for further research.

  9. Microcontroller Based Solar tracking System for enhancing efficiency of a Photovoltaic system

    Directory of Open Access Journals (Sweden)

    Shaifali Jain,

    2014-09-01

    Full Text Available In today‟s scenario of increasing energy needs, there is a huge dependence on renewable energy sources along with the conventional sources. One of the most important renewable energy resources is the sun. However, the problem with solar power is that it is directly dependent on light intensity. To produce the maximum amount of energy, a solar panel must be perpendicular to the light source. Because the sun moves both throughout the day as well as throughout a year, a solar panel must be able to follow the sun‟s movement to produce the maximum possible power. There are a large number of methods available for solar tracking and hence maximizing the output .This paper proposes an Arduino Uno microcontroller board based solar tracking system. As compared to the conventional solar panels, the one mounted with microcontroller based tracking system will give enhanced output.

  10. Recent developments in amorphous silicon-based solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Beneking, C.; Rech, B.; Foelsch, J.; Wagner, H. [Forschungszentrum Juelich GmbH (Germany). Inst. fuer Schicht- und Ionentechnik

    1996-03-01

    Two examples of recent advances in the field of thin-film, amorphous hydrogenated silicon (a-Si:H) pin solar cells are described: the improved understanding and control of the p/i interface, and the improvement of wide-bandgap a-Si:H material deposited at low substrate temperature as absorber layer for cells with high stabilized open-circuit voltage. Stacked a-Si:H/a-Si:H cells incorporating these concepts exhibit less than 10% (relative) efficiency degradation and show stabilized efficiencies as high as 9 to 10% (modules 8 to 9%). The use of low-gap a-Si:H and its alloys like a-SiGe:H as bottom cell absorber materials in multi-bandgap stacked cells offers additional possibilities. The combination of a-Si:H based top cells with thin-film crystalline silicon-based bottom cells appears as a promising new trend. It offers the perspective to pass significantly beyond the present landmark of 10% module efficiency reached by the technology utilizing exclusively amorphous silicon-based absorber layers, while keeping its advantages of potentially low-cost production. (orig.) 47 refs.

  11. Investigation of Organic Solar Cells Based on Donor——A ccepter Heterojunction%Investigation of Organic Solar Cells Based onDonor——A ccepter Heterojunction

    Institute of Scientific and Technical Information of China (English)

    Gao Yinhao

    2008-01-01

    The single-l ayer structure and heterojunction structure organic solar cells based on copper phthalocyanine (CuPc),3,4,9,10-Perylenetetracarboxylic dianhydride (PTCDA) and fullerene C60 were fabricated to study their photovoltaic (PV) properties. The PV performance of heterojunction structure solar cells was improved compared with the single layer structure cell.This is due to the introduction of donor-acceptor heterojunction that both expands the absorption range and offers efficient excit on dissociation site.In heterojunction structure solar cells,the PV performance of device with C60 as acceptor has highly improved because C60 has longer diffusion length o f excitons.

  12. Photoelectrochemical solar cells based on Bi{sub 2}WO{sub 6}; Celdas solares fotoelectroquimicas basadas en Bi{sub 2}WO{sub 6}

    Energy Technology Data Exchange (ETDEWEB)

    Madriz, Lorean; Tata, Jose; Cuartas, Veronica; Cuellar, Alejandra; Vargas, Ronald, E-mail: lmadriz@usb.ve [Departamento de Quimica, Universidad Simon Bolivar, Caracas (Venezuela, Bolivarian Republic of)

    2014-04-15

    In this study, photoelectrochemical solar cells based on bismuth tungstate electrodes were evaluated. Bi{sub 2}WO{sub 6} was synthesized by a hydrothermal method and characterized by scanning electron microscopy, UV-Vis reflectance spectroscopy, and X-ray powder diffraction. For comparison, solar cells based on TiO{sub 2} semiconductor electrodes were evaluated. Photoelectrochemical response of Grätzel-type solar cells based on these semiconductors and their corresponding sensitization with two inexpensive phthalocyanines dyes were determined. Bi{sub 2}WO{sub 6}-based solar cells presented higher values of photocurrent and efficiency than those obtained with TiO{sub 2} electrodes, even without sensitization. These results portray solar cells based on Bi{sub 2}WO{sub 6} as promising devices for solar energy conversion owing to lower cost of production and ease of acquisition. (author)

  13. Device modeling of perovskite solar cells based on structural similarity with thin film inorganic semiconductor solar cells

    Science.gov (United States)

    Minemoto, Takashi; Murata, Masashi

    2014-08-01

    Device modeling of CH3NH3PbI3-xCl3 perovskite-based solar cells was performed. The perovskite solar cells employ a similar structure with inorganic semiconductor solar cells, such as Cu(In,Ga)Se2, and the exciton in the perovskite is Wannier-type. We, therefore, applied one-dimensional device simulator widely used in the Cu(In,Ga)Se2 solar cells. A high open-circuit voltage of 1.0 V reported experimentally was successfully reproduced in the simulation, and also other solar cell parameters well consistent with real devices were obtained. In addition, the effect of carrier diffusion length of the absorber and interface defect densities at front and back sides and the optimum thickness of the absorber were analyzed. The results revealed that the diffusion length experimentally reported is long enough for high efficiency, and the defect density at the front interface is critical for high efficiency. Also, the optimum absorber thickness well consistent with the thickness range of real devices was derived.

  14. Thermal performance of a solar cooker based on an evacuated tube solar collector with a PCM storage unit

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, S.D.; Sagara, Kazunobu [Osaka Univ., Dept. of Architectural Engineering, Suita, Osaka (Japan); Iwata, Takeshi; Kitano, Hiroaki [Mie Univ., Dept. of Architecture, Tsu (Japan)

    2005-03-01

    The thermal performance of a prototype solar cooker based on an evacuated tube solar collector with phase change material (PCM) storage unit is investigated. The design has separate parts for energy collection and cooking coupled by a PCM storage unit. Solar energy is stored in the PCM storage unit during sunshine hours and is utilized for cooking in late evening/night time. Commercial grade erythritol was used as a latent heat storage material. Noon and evening cooking experiments were conducted with different loads and loading times. Cooking experiments and PCM storage processes were carried out simultaneously. It was observed that noon cooking did not affect the evening cooking, and evening cooking using PCM heat storage was found to be faster than noon cooking. The cooker performance under a variety of operating and climatic conditions was studied at Mie, Japan. (Author)

  15. 76 FR 63614 - Agua Caliente Solar, LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes...

    Science.gov (United States)

    2011-10-13

    ...-000] Agua Caliente Solar, LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes... proceeding of Agua Caliente Solar, LLC's application for market-based rate authority, with an...

  16. Solar shading system based on daylight directing glass lamellas

    DEFF Research Database (Denmark)

    Laustsen, Jacob B.; Santos, Ines D. P.; Svendsen, Svend;

    2008-01-01

    The overheating problems in office buildings must be solved with efficient solar shadings in order to reduce the energy demand for cooling and ventilation. At the same time the solar shading should not reduce the daylight level in the building on overcast days because it would result in a lower...

  17. Bulk heterojunction organic solar cells based on merocyanine colorants.

    Science.gov (United States)

    Kronenberg, Nils M; Deppisch, Manuela; Würthner, Frank; Lademann, Hans W A; Deing, Kaja; Meerholz, Klaus

    2008-12-28

    Traditional low-molecular weight colorants that are widely applied in textile coloration, for printing purposes and nonlinear optics, now afford bulk heterojunction solar cells in combination with soluble C(60) fullerene derivative PCBM with power conversion efficiencies up to 1.7% under standard solar radiation.

  18. A New Fuzzy-Based Maximum Power Point Tracker for a Solar Panel Based on Datasheet Values

    OpenAIRE

    Ali Kargarnejad; Mohsen Taherbaneh; Amir Hosein Kashefi

    2013-01-01

    Tracking maximum power point of a solar panel is of interest in most of photovoltaic applications. Solar panel modeling is also very interesting exclusively based on manufacturers data. Knowing that the manufacturers generally give the electrical specifications of their products at one operating condition, there are so many cases in which the specifications in other conditions are of interest. In this research, a comprehensive one-diode model for a solar panel with maximum obtainable accuracy...

  19. 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.

  20. Hydrogenated indium oxide window layers for high-efficiency Cu(In,Ga)Se{sub 2} solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Jäger, Timo, E-mail: timo.jaeger@empa.ch; Romanyuk, Yaroslav E.; Nishiwaki, Shiro; Bissig, Benjamin; Pianezzi, Fabian; Fuchs, Peter; Gretener, Christina; Tiwari, Ayodhya N. [Empa – Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Thin Films and Photovoltaics, Überlandstrasse 129, 8600 Dübendorf (Switzerland); Döbeli, Max [ETH Zürich, Swiss Federal Institute of Technology, Laboratory of Ion Beam Physics, Otto-Stern-Weg 5, 8093 Zürich (Switzerland)

    2015-05-28

    High mobility hydrogenated indium oxide is investigated as a transparent contact for thin film Cu(In,Ga)Se{sub 2} (CIGS) solar cells. Hydrogen doping of In{sub 2}O{sub 3} thin films is achieved by injection of H{sub 2}O water vapor or H{sub 2} gas during the sputter process. As-deposited amorphous In{sub 2}O{sub 3}:H films exhibit a high electron mobility of ∼50 cm{sup 2}/Vs at room temperature. A bulk hydrogen concentration of ∼4 at. % was measured for both optimized H{sub 2}O and H{sub 2}-processed films, although the H{sub 2}O-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 (V{sub OC}) of ∼20 mV regardless of the doping approach, whereas the short circuit current and fill factor remain the same for the H{sub 2}O case or slightly decrease for H{sub 2}. The overall power conversion efficiency is improved from 15.7% to 16.2% by substituting ZnO:Al with IOH (H{sub 2}O) 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.

  1. Efficiency Investigation of Dye-Sensitized Solar Cells Based on the Zinc Oxide Nanowires

    Directory of Open Access Journals (Sweden)

    Ahmad Afifi

    2014-03-01

    Full Text Available In this paper, we synthesized ZnO nanowires in dye sensitized solar cells. The nanowires have been fabricated using fast-microwave-hydrothermal process.We verify the effects of different lengths of ZnO nanowires on efficiency and absorptionofdye sensitized solar cells. J–V curves of the fabricated ZnO nanowire-based mercurochrome-sensitized solar cellsindicated that the short-circuit current density wouldincrease with increasing the length of nanowires.We also fabricate more efficient N719-sensitized solar cellsand investigate the effect of different length of Zno nanowires on the efficiency.

  2. Mathematical Modeling of a developed Central Receiver Based on Evacuated Solar Tubes

    Directory of Open Access Journals (Sweden)

    Ali Basil. H.

    2016-01-01

    Full Text Available Solar central receiver plays a considerable role in the plant output power; it is one of the most important synthesis in the solar power tower plants. Its performance directly affects the efficiency of the entire solar power generation system. In this study, a new designed receiver model based on evacuated solar tube was proposed, and the dynamic characteristics of the developed receiver were investigated. In order to optimise and evaluate the dynamic characteristics of solar power plant components, the model investigates the solar radiation heat conversion process through the developed receiver, where the energy and mass conservation equations are used to determine the working fluid temperature and state through the receiver parts, beside the calculation and analysis of the thermal losses.

  3. High-Efficiency Polycrystalline Thin Film Tandem Solar Cells.

    Science.gov (United States)

    Kranz, Lukas; Abate, Antonio; Feurer, Thomas; Fu, Fan; Avancini, Enrico; Löckinger, Johannes; Reinhard, Patrick; Zakeeruddin, Shaik M; Grätzel, Michael; Buecheler, Stephan; Tiwari, Ayodhya N

    2015-07-16

    A promising way to enhance the efficiency of CIGS solar cells is by combining them with perovskite solar cells in tandem devices. However, so far, such tandem devices had limited efficiency due to challenges in developing NIR-transparent perovskite top cells, which allow photons with energy below the perovskite band gap to be transmitted to the bottom cell. Here, a process for the fabrication of NIR-transparent perovskite solar cells is presented, which enables power conversion efficiencies up to 12.1% combined with an average sub-band gap transmission of 71% for photons with wavelength between 800 and 1000 nm. The combination of a NIR-transparent perovskite top cell with a CIGS bottom cell enabled a tandem device with 19.5% efficiency, which is the highest reported efficiency for a polycrystalline thin film tandem solar cell. Future developments of perovskite/CIGS tandem devices are discussed and prospects for devices with efficiency toward and above 27% are given.

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

    Directory of Open Access Journals (Sweden)

    R. S. Dubey

    2014-12-01

    Full Text Available The influence of various designing parameters were investigated and explored for high performance solar cells. Single layer grating based solar cell of 50 μm thickness gives maximum efficiency up to 24 % whereas same efficiency is achieved with the use of three bilayers grating based solar cell of 30 μm thickness. Remarkably, bilayer grating based solar cell design not only gives broadband absorption but also enhancement in efficiency with reduced cell thickness requirement. This absorption enhancement is attributed to the high reflection and diffraction from DBR and grating respectively. The obtained short-circuit current were 29.6, 32.9, 34.6 and 36.05 mA/cm2 of 5, 10, 20 and 30 μm cell thicknesses respectively. These presented designing efforts would be helpful to design and realize new generation of solar cells.

  5. Key Success Factors and Future Perspective of Silicon-Based Solar Cells

    Directory of Open Access Journals (Sweden)

    S. Binetti

    2013-01-01

    Full Text Available Today, after more than 70 years of continued progress on silicon technology, about 85% of cumulative installed photovolatic (PV modules are based on crystalline silicon (c-Si. PV devices based on silicon are the most common solar cells currently being produced, and it is mainly due to silicon technology that the PV has grown by 40% per year over the last decade. An additional step in the silicon solar cell development is ongoing, and it is related to a further efficiency improvement through defect control, device optimization, surface modification, and nanotechnology approaches. This paper attempts to briefly review the most important advances and current technologies used to produce crystalline silicon solar devices and in the meantime the most challenging and promising strategies acting to increase the efficiency to cost/ratio of silicon solar cells. Eventually, the impact and the potentiality of using a nanotechnology approach in a silicon-based solar cell are also described.

  6. Progress on an Updated National Solar Radiation Data Base for the United States: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Wilcox, S.; Anderberg, M.; George, R.; Marion, W.; Myers, D.; Renne, D.; Beckman, W.; DeGaetano, A.; Gueymard, C.; Perez, R.; Plantico, M.; Stackhouse, P.; Vignola, F.

    2005-09-01

    In 1992, The National Renewable Energy Laboratory (NREL) released the 1961-1990 National Solar Radiation Data Base (NSRDB), a 30-year set of hourly solar radiation data. In 2003, NREL undertook an NSRDB update project for the decade of 1991-2000.

  7. Progress on an Updated National Solar Radiation Data Base for the United States

    Energy Technology Data Exchange (ETDEWEB)

    Wilcox, S.; Anderberg, M.; George, R.; Marion, W.; Myers, D.; Renne, D.; Beckman, W.; DeGaetano, A.; Gueymard, C.; Perez, R.; Plantico, M.; Stackhouse, P.; Vignola, F.

    2005-01-01

    In 1992, the National Renewable Energy Laboratory (NREL) released the 1961-1990 National Solar Radiation Data Base (NSRDB), a 30-year set of hourly solar radiation data. In 2003, NREL undertook an NSRDB update project for the decade of 1991-2000. This paper describes recent work on the project and evaluation of the test data set.

  8. A solar receiver-storage modular cascade based on porous ceramic structures for hybrid sensible/thermochemical solar energy storage

    Science.gov (United States)

    Agrafiotis, Christos; de Oliveira, Lamark; Roeb, Martin; Sattler, Christian

    2016-05-01

    The current state-of-the-art solar heat storage concept in air-operated Solar Tower Power Plants is to store the solar energy provided during on-sun operation as sensible heat in porous solid materials that operate as recuperators during off-sun operation. The technology is operationally simple; however its storage capacity is limited to 1.5 hours. An idea for extending this capacity is to render this storage concept from "purely" sensible to "hybrid" sensible/ thermochemical one, via coating the porous heat exchange modules with oxides of multivalent metals for which their reduction/oxidation reactions are accompanied by significant heat effects, or by manufacturing them entirely of such oxides. In this way solar heat produced during on-sun operation can be used (in addition to sensibly heating the porous solid) to power the endothermic reduction of the oxide from its state with the higher metal valence to that of the lower; the thermal energy can be entirely recovered by the reverse exothermic oxidation reaction (in addition to sensible heat) during off-sun operation. Such sensible and thermochemical storage concepts were tested on a solar-irradiated receiver- heat storage module cascade for the first time. Parametric studies performed so far involved the comparison of three different SiC-based receivers with respect to their capability of supplying solar-heated air at temperatures sufficient for the reduction of the oxides, the effect of air flow rate on the temperatures achieved within the storage module, as well as the comparison of different porous storage media made of cordierite with respect to their sensible storage capacity.

  9. PbSe quantum dot based luminescent solar concentrators

    Science.gov (United States)

    Waldron, Dennis L.; Preske, Amanda; Zawodny, Joseph M.; Krauss, Todd D.; Gupta, Mool C.

    2017-03-01

    The results are presented for luminescent solar concentrators (LSCs) fabricated with poly(lauryl methacrylate-co-ethylene glycol dimethacrylate) (P(LMA-co-EGDMA)) and Angstrom Bond, Inc. AB9093 acrylic epoxy matrix, high quantum yield (> 70%) PbSe quantum dots (QDs) and silicon photovoltaic (Si PV) cells. LSCs were tested under a lamp with broadband illumination, photon flux-matched to a standard solar spectrum and verified under a calibrated solar lamp source. The P(LMA-co-EGDMA) sample demonstrated the highest power conversion efficiency of any known LSC fabricated with either QDs or Si PV cells, 4.74%. Additionally, increased temperature was shown to reduce efficiency.

  10. Hole transport parameters in a PTOPT based organic solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Gebremichael, B. [Addis Ababa Univ., Addis Ababa (Ethiopia). Dept. of Physics; Tessema, G. [Addis Ababa Univ., Addis Ababa (Ethiopia). Dept. of Physics; National Univ. of Lesotho (Lesotho). Dept. of Physics and Electronics

    2010-05-15

    Semiconductor polymers are light-weight and inexpensive to manufacture. As such, they are in demand for solar cell applications. In this study, a single layer photovoltaic (PV) device was used to examine the charge transport phenomena in a photoactive layer made of poly[3-(4-octylphenyl)-2, 2{sup '}-bithiophene] (PTOPT). The devices were prepared in a sandwich-type structure of the form Al/PTOPT/PEDOT:PSS/ITO. The diodes exhibited good rectification which is required in a PV cell. The device rectified at room temperature and lost rectification at around 273 K. The loss of rectification at low temperatures was due to the injection of holes from the aluminium electrode that rendered the device hole-dominated. The symmetric nature of the semilogarithmic J-V plot under dark and low temperature demonstrated that there is a unipolar charge injection in both sides of the electrodes. Based on the space charge limited region J-V data, it was possible to examine the electric field dependence of the hole transport. Important parameters such as the zero field mobility and the field activation factor were then derived. 9 refs., 4 figs.

  11. 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).

  12. InN-Based Quantum Dot Solar Cells Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of this STTR program is to employ nanostructured materials in advanced device designs to enhance the tolerance of solar cells to extreme conditions while...

  13. InN-Based Quantum Dot Solar Cells Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of this STTR program is to employ nanostructured materials in an advanced device design to enhance the tolerance of solar cells to extreme environments...

  14. Solar process heat. Citations from the NTIS data base

    Science.gov (United States)

    Hundemann, A. S.

    1980-04-01

    Feasibility, design, cost, and economic potential of solar process heat are discussed. Potential applications to industries using hot water or steam and to heat used for dehydration processes in agriculture are covered. Contains 60 abstracts.

  15. A Wavelet Based Approach to Solar--Terrestrial Coupling

    CERN Document Server

    Katsavrias, Ch; Preka--Papadema, P

    2016-01-01

    Transient and recurrent solar activity drive geomagnetic disturbances; these are quantified (amongst others) by DST, AE indices time-series. Transient disturbances are related to the Interplanetary Coronal Mass Ejections (ICMEs) while recurrent disturbances are related to corotating interaction regions (CIR). We study the relationship of the geomagnetic disturbances to the solar wind drivers within solar Cycle 23 where the drivers are represented by ICMEs and CIRs occurrence rate and compared to the DST and AE as follows: terms with common periodicity in both the geomagnetic disturbances and the solar drivers are, firstly, detected using continuous wavelet transform (CWT). Then, common power and phase coherence of these periodic terms are calculated from the cross-wavelet spectra (XWT) and waveletcoherence (WTC) respectively. In time-scales of about 27 days our results indicate an anti-correlation of the effects of ICMEs and CIRs on the geomagnetic disturbances. The former modulates the DST and AE time series...

  16. Forbush Decrease Prediction Based on the Remote Solar Observations

    OpenAIRE

    Dumbovic, Mateja; Vrsnak, Bojan; Calogovic, Jasa

    2015-01-01

    We employ remote observations of coronal mass ejections (CMEs) and the associated solar flares to forecast the CME-related Forbush decreases, i.e., short-term depressions in the galactic cosmic-ray flux. The relationship between the Forbush effect at the Earth and remote observations of CMEs and associated solar flares is studied via a statistical analysis. Relationships between Forbush decrease magnitude and several CME/flare parameters was found, namely the initial CME speed, apparent width...

  17. A wavelet based approach to Solar-Terrestrial Coupling

    Science.gov (United States)

    Katsavrias, Ch.; Hillaris, A.; Preka-Papadema, P.

    2016-05-01

    Transient and recurrent solar activity drive geomagnetic disturbances; these are quantified (amongst others) by DST , AE indices time-series. Transient disturbances are related to the Interplanetary Coronal Mass Ejections (ICMEs) while recurrent disturbances are related to corotating interaction regions (CIR). We study the relationship of the geomagnetic disturbances to the solar wind drivers within solar cycle 23 where the drivers are represented by ICMEs and CIRs occurrence rate and compared to the DST and AE as follows: terms with common periodicity in both the geomagnetic disturbances and the solar drivers are, firstly, detected using continuous wavelet transform (CWT). Then, common power and phase coherence of these periodic terms are calculated from the cross-wavelet spectra (XWT) and wavelet-coherence (WTC) respectively. In time-scales of ≈27 days our results indicate an anti-correlation of the effects of ICMEs and CIRs on the geomagnetic disturbances. The former modulates the DST and AE time series during the cycle maximum the latter during periods of reduced solar activity. The phase relationship of these modulation is highly non-linear. Only the annual frequency component of the ICMEs is phase-locked with DST and AE. In time-scales of ≈1.3-1.7 years the CIR seem to be the dominant driver for both geomagnetic indices throughout the whole solar cycle 23.

  18. A solar vehicle based on sustainable design concept

    Energy Technology Data Exchange (ETDEWEB)

    Taha, Z.; Sah, J.M.; Passarella, R.; Ghazilla, R.A.R.; Ahmad, N.; Jen, Y.H.; Khai, T.T.; Kassim, Z.; Hasanuddin, I.; Yunus, M. [Malaya Univ., Kuala Lumpur (Malaysia). Faculty of Engineering, Centre for Product Design and Manufacture

    2009-07-01

    This paper described a newly constructed solar vehicle that was built specifically for the 2009 World Solar Challenge (WSC) using off-the-shelf parts. Researchers at the Centre for Product Design and Manufacture at the University of Malaya designed and built the solar car which uses solar energy to charge its batteries. Although the total investment for this sustainable product concept is small compared to other solar vehicles, the car's performance has met expectations. Most of the electrical and mechanical parts can be recycled and reused after the WSC event. The photovoltaic (PV) and maximum power point trackers (MPPT) can be re-used for home applications. The DC motor and the controller can be attached to a bicycle and the aluminium parts which make-up the main body structure can be recycled. The design will result in nearly zero waste. The study showed that the process of combining mechanical and electrical components is not an easy task, particularly at the design stage because of the specific characteristics and functions of the individual parts. This paper described how readily available, off-the-shelf mechanical and electrical components were integrated for the solar vehicle. The conceptual design and the performance of the prototype were also presented. 11 refs., 5 tabs., 11 figs.

  19. Performance Evaluation of a Nanofluid (CuO-H2O Based Low Flux Solar Collector

    Directory of Open Access Journals (Sweden)

    Lal Kundan

    2013-04-01

    Full Text Available As the fossil fuels are depleting continuously, we know that solar energy harvesting is a significant potential area for new research dimensions. Sun provides us about 1.9 x 108TWh/yr on the land, of which 1.3 x 105 TWh]/yr energy is used. In order to make much use of solar energy on the earth, solar energy harvesting into more usable form (e.g. heat or electricity by using solar energy collectors is important aspect. A solar collector [1] is a device which transfers the collected solar energy to a fluid passing in contact with it. The performance of collector does not only depends upon how effective the absorber is, but also on how effective are the heat transfer and thermal properties (e.g. thermal conductivity, heat capacity of the fluid which is being used. The absorption properties of the fluids generally used in solar collectors are very poor which in turn limits the efficiency of the solar collector. So, there is a need to use energy efficient heat transfer fluids for high efficiency and performance. A relatively new attempt has been made to increase the performance of the solar collector by using nanofluids. Recently developed a new class of working fluids called Nanofluids, found to be possessing better thermal properties over the hosting fluids, can be a good option in the solar collector [5]. In our research work the CuO-water based nanofluid has been tested in the solar collector and their performance is investigated. It has been found that efficiency if the solar collector is increased by 4-6% compared to water

  20. 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%.

  1. Uniform, High Efficiency, Hybrid CIGS Process with Application to Novel Device Structures: Annual Technical Report, 15 March 2005 - 14 March 2006

    Energy Technology Data Exchange (ETDEWEB)

    Delahoy, A. E.; Chen, L.; Sang, B.

    2006-06-01

    One of the main Phase I objectives of this subcontract was for EPV to demonstrate 14%-efficient CIGS devices using a hybrid process. The processing was also required to have good control ability. These goals were successfully accomplished. It will be seen that during Phase I, we successfully developed a new, simplified hybrid process. A highlight of intensive work was the achievement of a 14.0% NREL-verified device at a CIGS thickness of 1.13 ..mu..m. The simplified hybrid process considerably reduces CIGS film formation time and offers the promise of being a truly cost-effective and manufacturable one. It is considered to be one of the more attractive CIGS processes in the industry.

  2. EVALUATION OF OPPORTUNITIES OF SOLAR ENERGETICS ON THE BASIS OF ACCURATE GROUND-BASED MEASUREMENTS OF SOLAR RADIATION

    Directory of Open Access Journals (Sweden)

    Aculinin A.

    2008-04-01

    Full Text Available Expected quantity of a solar energy received by solar panel is estimated on the basis of accurate measurements of solar radiation in Kishinev. Optimal orientation of solar panels and apparent volume of the electric power generated by solar panels are determined.

  3. Highly Efficient InGaN-Based Solar Cells for High Intensity and High Temperature Operation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this SBIR Phase I program, we propose to fabricate high-efficiency and radiation hard solar cells based on InGaN material system that can cover the whole solar...

  4. Solar Hydrogen Production via a Samarium Oxide-Based Thermochemical Water Splitting Cycle

    OpenAIRE

    Rahul Bhosale; Anand Kumar; Fares AlMomani; Ujjal Ghosh; Mohammad Saad Anis; Konstantinos Kakosimos; Rajesh Shende; Marc A. Rosen

    2016-01-01

    The computational thermodynamic analysis of a samarium oxide-based two-step solar thermochemical water splitting cycle is reported. The analysis is performed using HSC chemistry software and databases. The first (solar-based) step drives the thermal reduction of Sm2O3 into Sm and O2. The second (non-solar) step corresponds to the production of H2 via a water splitting reaction and the oxidation of Sm to Sm2O3. The equilibrium thermodynamic compositions related to the thermal reduction and wat...

  5. Intermediate-Band Solar Cells Based on InAs/GaAs Quantum Dots

    Institute of Scientific and Technical Information of China (English)

    YANG Xiao-Guang; CHEN Yan-Ling; WANG Zhan-Guo; YANG Tao; WANG Ke-Fan; GU Yong-Xian; JI Hai-Ming; XU Peng-Fei; NI Hai-Qiao; NIU Zhi-Chuan; WANG Xiao-Dong

    2011-01-01

    We report the fabrication of intermediate-band solar cells(IBSCs) based on quantum dots(QDs), which consists of a standard P-I-N structure with multilayer stacks of InAs/GaAs QDs in the I-layer. Compared with conventional GaAs single-junction solar cells, the IBSCs based on InAs/GaAs QDs show a broader photo-response spectrum (> 1330 nm), a higher short-circle current(about 53% increase) and a stronger radiation hardness. The results have important applications for realizing high efficiency solar cells with stronger radiation hardness.

  6. Notas sobre Feral y las cigüeñas, de Fernando Alonso, y la "Historia del califa cigüeña" (Wilhelm Hauff, Sara Cone Bryant

    Directory of Open Access Journals (Sweden)

    Hans Christian Hagedorn

    2011-01-01

    Full Text Available En el presente estudio se analizan las fuentes de la versión de la "Historia del califa cigüeña", incluida en la narración Feral y las cigüeñas (1971, de Fernando Alonso. Para ello se tienen en cuenta el cuento original del autor postromántico alemán Wilhelm Hauff ("Die Geschichte von Kalif Storch", 1825, y la adaptación de este cuento que Sara Cone Bryant realizó para su libro How to tell stories to children (1905, traducción española: El arte de contar cuentos, 1965.

  7. Bulk-heterojunction organic solar cells based on merocyanine colorants

    Energy Technology Data Exchange (ETDEWEB)

    Kronenberg, Nils M.; Lademann, Hans W.A.; Meerholz, Klaus [Department fuer Chemie, Universitaet zu Koen (Germany); Buerckstuemmer, Hannah; Tulyakova, Elena V.; Deppisch, Manuela; Wuerthner, Frank [Institut fuer Organische Chemie, Universitaet Wuerzburg (Germany)

    2009-07-01

    To take advantage of the full potential of organic Bulk Heterojunction (BHJ) solar cells, there is a need to explore new materials. We introduced merocyanines dyes (MCs) as a new class of electron donor materials for the application in solution-processed BHJ solar cells. MCs are traditional low-molecular colorants that are widely applied in textile coloration, for printing purposes, and nonlinear optics. Due to their structure, consisting of an electron-donating and an electron-accepting subunit, they possess high absorption coefficients which is favorable for the use in solar cells. The vast variety of the MC synthesis allows for a variation of the absorption properties in a wide range and a tuning of the solar cell absorption to the emission spectrum of the sun. Another advantage of MCs compared to some long-wavelength absorbing polymers is the relatively low HOMO-energy (down to -6.0 eV), which is beneficial for large open-circuit voltages. We tested various different MC-dyes in the application as donor compound in BHJ solar cells in combination with the soluble C{sub 60} derivative PCBM. Power conversion efficiencies up to 2.1% under standard illumination and 2.7% at reduced intensities were achieved.

  8. Solar Energy Campaign. 2008 Norwegian student-based web campaign

    Energy Technology Data Exchange (ETDEWEB)

    Randall, Scott

    2009-07-01

    Student research campaigns (forskningskampanjer) have been an annual event in connection to Research Days (Forskningsdagene) since 2003 in Norway. The campaigns invite students from all over the country to participate in a common scientific research event, always connected to a special environmentally related theme - for example Air Quality in the Classroom (2003), Pollution along Roads (2004), Bacteria in Drinking Water (2005), and The Rain Check (2006). The year 2008, as with previous years, was overshadowed by the topic of climate change, and the specific role of humans. The research campaign theme for 2008 fit well into this focus: the potential benefits of solar energy as an alternative energy source. The campaign also was aligned with the Research Days theme of alternative energy sources and technologies. The campaign included the hands-on activity of assembling a solar panel and taking measurements with the device to determine efficiency, as well as a questionnaire to record the results and ask deeper questions regarding alternative energy and climate change. The results gained from data analysis of the campaign show that students were able to gain maximum efficient solar power from the devices they constructed, which gave them a solid understanding of solar power technology. Analysis of the campaign questionnaire in regards to the activity shows that students believe that solar energy should be better utilized as an energy source in Norway. (Also in Norwegian OR 24/2009). (Author)

  9. Porphyrin-Based Dye-Sensitized Solar Cells (DSSCs): a Review.

    Science.gov (United States)

    Birel, Özgül; Nadeem, Said; Duman, Hakan

    2017-02-16

    The current review aims to collect short information about photovoltaic performance and structure of porphyrin-based sensitizers used in dye-sensitized solar cells (DSSC). Sensitizer is the key component of the DSSC device. Structure of sensitizer is important to achieve high photovoltaic performance. Porphyrin derivatives are suitable for DSSC applications due to their thermal, electronic and photovoltaic properties. It describes some electrochemical and spectral properties as well as thestructure of porphyrin dyes used in dye based-solar cells.

  10. Characterization of Air-Based Photovoltaic Thermal Panels with Bifacial Solar Cells

    OpenAIRE

    P. Ooshaksaraei; K. Sopian; R. Zulkifli; Saleem H. Zaidi

    2013-01-01

    Photovoltaic (PV) panels account for a majority of the cost of photovoltaic thermal (PVT) panels. Bifacial silicon solar panels are attractive for PVT panels because of their potential to enhance electrical power generation from the same silicon wafer compared with conventional monofacial solar panels. This paper examines the performance of air-based bifacial PVT panels with regard to the first and second laws of thermodynamics. Four air-based bifacial PVT panels were designed. The maximum ef...

  11. 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%.

  12. Radiative efficiency of lead iodide based perovskite solar cells

    Science.gov (United States)

    Tvingstedt, Kristofer; Malinkiewicz, Olga; Baumann, Andreas; Deibel, Carsten; Snaith, Henry J.; Dyakonov, Vladimir; Bolink, Henk J.

    2014-08-01

    The maximum efficiency of any solar cell can be evaluated in terms of its corresponding ability to emit light. We herein determine the important figure of merit of radiative efficiency for Methylammonium Lead Iodide perovskite solar cells and, to put in context, relate it to an organic photovoltaic (OPV) model device. We evaluate the reciprocity relation between electroluminescence and photovoltaic quantum efficiency and conclude that the emission from the perovskite devices is dominated by a sharp band-to-band transition that has a radiative efficiency much higher than that of an average OPV device. As a consequence, the perovskite have the benefit of retaining an open circuit voltage ~0.14 V closer to its radiative limit than the OPV cell. Additionally, and in contrast to OPVs, we show that the photoluminescence of the perovskite solar cell is substantially quenched under short circuit conditions in accordance with how an ideal photovoltaic cell should operate.

  13. Quantum-Dot-Based Solar Cells: Recent Advances, Strategies, and Challenges.

    Science.gov (United States)

    Kim, Mee Rahn; Ma, Dongling

    2015-01-02

    Among next-generation photovoltaic systems requiring low cost and high efficiency, quantum dot (QD)-based solar cells stand out as a very promising candidate because of the unique and versatile characteristics of QDs. The past decade has already seen rapid conceptual and technological advances on various aspects of QD solar cells, and diverse opportunities, which QDs can offer, predict that there is still ample room for further development and breakthroughs. In this Perspective, we first review the attractive advantages of QDs, such as size-tunable band gaps and multiple exciton generation (MEG), beneficial to solar cell applications. We then analyze major strategies, which have been extensively explored and have largely contributed to the most recent and significant achievements in QD solar cells. Finally, their high potential and challenges are discussed. In particular, QD solar cells are considered to hold immense potential to overcome the theoretical efficiency limit of 31% for single-junction cells.

  14. 25th Anniversary Article: Rise to Power – OPV-Based Solar Parks

    DEFF Research Database (Denmark)

    Krebs, Frederik C; Espinosa Martinez, Nieves; Hösel, Markus

    2014-01-01

    A solar park based on polymer solar cells is described and analyzed with respect to performance, practicality, installation speed, and energy payback time. It is found that a high voltage installation where solar cells are all printed in series enables an installation rate in Watts installed per...... minute that far exceed any other PV technology in existence. The energy payback time for the practical installation of polymer solar cell foil on a wooden 250 square meter platform in its present form is 277 days when operated in Denmark and 180 days when operated in southern Spain. The installation...... and de-installation rate is above 100 m min−1 , which, with the present performance and web width, implies installation of >200 W min−1. In comparison, this also exceeds the overall manufacturing speed of the polymer solar cell foil with a width of 305 mm which is currently 1 m min−1 for complete...

  15. An Investigation of High Performance Heterojunction Silicon Solar Cell Based on n-type Si Substrate

    Directory of Open Access Journals (Sweden)

    N. Memarian

    2016-12-01

    Full Text Available In this study, high efficient heterojunction crystalline silicon solar cells without using an intrinsic layer were systematically investigated. The effect of various parameters such as work function of transparent conductive oxide (ϕTCO, density of interface defects, emitter and crystalline silicon thickness on heterojunction silicon solar cell performance was studied. In addition, the effect of band bending and internal electric field on solar cell performance together with the dependency of cell performance on work function and reflectance of the back contact were investigated in full details. The optimum values of the solar cell properties for the highest efficiency are presented based on the results of the current study. The results represent a complete set of optimum values for a heterojunction solar cell with high efficiency up to the 24.1 % with VOC  0.87 V and JSC  32.69 mAcm – 2.

  16. Dye-sensitized solar cells based on purple corn sensitizers

    Science.gov (United States)

    Phinjaturus, Kawin; Maiaugree, Wasan; Suriharn, Bhalang; Pimanpaeng, Samuk; Amornkitbamrung, Vittaya; Swatsitang, Ekaphan

    2016-09-01

    Natural dye extracted from husk, cob and silk of purple corn, were used for the first time as photosensitizers in dye sensitized solar cells (DSSCs). The dye sensitized solar cells fabrication process has been optimized in terms of solvent extraction. The resulting maximal efficiency of 1.06% was obtained from purple corn husk extracted by acetone. The ultraviolet-visible (UV-vis) spectroscopy, Fourier transform infrared spectroscopy (FTIR), electrochemical impedance spectroscopy (EIS) and incident photon-to-current efficiency (IPCE) were employed to characterize the natural dye and the DSSCs.

  17. The Design of the LED Display based on Solar Energy

    Directory of Open Access Journals (Sweden)

    Li Pei

    2015-01-01

    Full Text Available The development of solar energy and the LED display, the superiority of the combination of them and software design of the system are discussed in this paper. Hardware design and software design are the key elements of this paper. Solar control circuit, LED display control circuit, etc are described, charge and discharge of the battery and output of the battery is controlled by STC89C52 SCM. The design of software provides driver to the related hardware circuit. The result of the experiment have achieved anticipated effects and met the design requirements.

  18. 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.

  19. Empirically modelled Pc3 activity based on solar wind parameters

    Directory of Open Access Journals (Sweden)

    T. Raita

    2010-09-01

    Full Text Available It is known that under certain solar wind (SW/interplanetary magnetic field (IMF conditions (e.g. high SW speed, low cone angle the occurrence of ground-level Pc3–4 pulsations is more likely. In this paper we demonstrate that in the event of anomalously low SW particle density, Pc3 activity is extremely low regardless of otherwise favourable SW speed and cone angle. We re-investigate the SW control of Pc3 pulsation activity through a statistical analysis and two empirical models with emphasis on the influence of SW density on Pc3 activity. We utilise SW and IMF measurements from the OMNI project and ground-based magnetometer measurements from the MM100 array to relate SW and IMF measurements to the occurrence of Pc3 activity. Multiple linear regression and artificial neural network models are used in iterative processes in order to identify sets of SW-based input parameters, which optimally reproduce a set of Pc3 activity data. The inclusion of SW density in the parameter set significantly improves the models. Not only the density itself, but other density related parameters, such as the dynamic pressure of the SW, or the standoff distance of the magnetopause work equally well in the model. The disappearance of Pc3s during low-density events can have at least four reasons according to the existing upstream wave theory: 1. Pausing the ion-cyclotron resonance that generates the upstream ultra low frequency waves in the absence of protons, 2. Weakening of the bow shock that implies less efficient reflection, 3. The SW becomes sub-Alfvénic and hence it is not able to sweep back the waves propagating upstream with the Alfvén-speed, and 4. The increase of the standoff distance of the magnetopause (and of the bow shock. Although the models cannot account for the lack of Pc3s during intervals when the SW density is extremely low, the resulting sets of optimal model inputs support the generation of mid latitude Pc3 activity predominantly through

  20. Multi-viewpoint Smartphone AR-based Learning System for Solar Movement Observations

    Directory of Open Access Journals (Sweden)

    Ke Tian

    2014-06-01

    Full Text Available Understanding solar movement (e.g., solar diurnal motion is difficult for those are beginning to learn about astronomy. Previous research has revealed that observation-based learning can help make astronomical phenomena clearer to understand for such learners. In this research, Smartphone Augmented Reality (AR technology and 3D content were used to develop a multi-viewpoint Smartphone AR-based learning system (M-VSARLS for solar movement observations that can be used in the real-world environment. The goal of this research is to assess the usefulness of the system, usability of the AR function and 3D content, and the overall effect of the system on the learner’s motivation through task-based experiments with follow-up questionnaires. The results show that the M-VSARL system is effective in improving the observational skills and learning ability of learners, and in enhancing their motivation to learn about solar movement.

  1. On the Uniqueness of Ideality Factor and Voltage Exponent of Perovskite-Based Solar Cells.

    Science.gov (United States)

    Agarwal, Sumanshu; Seetharaman, Madhu; Kumawat, Naresh K; Subbiah, Anand S; Sarkar, Shaibal K; Kabra, Dinesh; Namboothiry, Manoj A G; Nair, Pradeep R

    2014-12-04

    Perovskite-based solar cells have attracted much recent research interest with efficiency approaching 20%. While various combinations of material parameters and processing conditions are attempted for improved performance, there is still a lack of understanding in terms of the basic device physics and functional parameters that control the efficiency. Here we show that perovskite-based solar cells have two universal features: an ideality factor close to two and a space-charge-limited current regime. Through detailed numerical modeling, we identify the mechanisms that lead to these universal features. Our model predictions are supported by experimental results on solar cells fabricated at five different laboratories using different materials and processing conditions. Indeed, this work unravels the fundamental operation principle of perovskite-based solar cells, suggests ways to improve the eventual performance, and serves as a benchmark to which experimental results from various laboratories can be compared.

  2. Solar-thermal conversion and thermal energy storage of graphene foam-based composites

    Science.gov (United States)

    Zhang, Lianbin; Li, Renyuan; Tang, Bo; Wang, Peng

    2016-07-01

    Among various utilizations of solar energy, solar-thermal conversion has recently gained renewed research interest due to its extremely high energy efficiency. However, one limiting factor common to all solar-based energy conversion technologies is the intermittent nature of solar irradiation, which makes them unable to stand-alone to satisfy the continuous energy need. Herein, we report a three-dimensional (3D) graphene foam and phase change material (PCM) composite for the seamlessly combined solar-thermal conversion and thermal storage for sustained energy release. The composite is obtained by infiltrating the 3D graphene foam with a commonly used PCM, paraffin wax. The high macroporosity and low density of the graphene foam allow for high weight fraction of the PCM to be incorporated, which enhances the heat storage capacity of the composite. The interconnected graphene sheets in the composite provide (1) the solar-thermal conversion capability, (2) high thermal conductivity and (3) form stability of the composite. Under light irradiation, the composite effectively collects and converts the light energy into thermal energy, and the converted thermal energy is stored in the PCM and released in an elongated period of time for sustained utilization. This study provides a promising route for sustainable utilization of solar energy.Among various utilizations of solar energy, solar-thermal conversion has recently gained renewed research interest due to its extremely high energy efficiency. However, one limiting factor common to all solar-based energy conversion technologies is the intermittent nature of solar irradiation, which makes them unable to stand-alone to satisfy the continuous energy need. Herein, we report a three-dimensional (3D) graphene foam and phase change material (PCM) composite for the seamlessly combined solar-thermal conversion and thermal storage for sustained energy release. The composite is obtained by infiltrating the 3D graphene foam with a

  3. CuInGaSe2薄膜太阳电池与关键薄膜材料的研究进展%Progress of CulnGaSe2 Thin Film Photovoltaic Cells and Solar Materials

    Institute of Scientific and Technical Information of China (English)

    万冬云; 黄富强

    2011-01-01

    对铜铟镓硒(CuInGaSe2,CIGS)薄膜太阳电池及关键薄膜材料的研究现状及发展方向进行了介绍.重点介绍了一种低成本制备高质量CIGS薄膜的非真空液相法技术,电池转换效率达13.83%.高性能关键电池材料的制备是电池高效和低成本的重要途径,可以实现薄膜太阳电池性能的稳定提升和技术的可持续发展.%This review presents recent developments on CulnGaSe2 (CIGS) thin film solar cells and the key solar materials (such as surface-textured ZnO:A1 transparent conducting films, graphene, and anti-reflection SiO2 coatings). A route to fabricate CIGS solar cells, which belongs to a non-vacuum low-cost method for producing CIGS solar cells, is proposed. The photovoltaic efficiency of the solar cell can be 13.83%. The fabrication of high performance key materials is the main route to reduce the cost and improve the efficiency of the solar cells which can realize the stable enhancement of the properties and the sustainable development of the photovoltaic cells.

  4. PSO Based PI Controller Design for a Solar Charger System

    Directory of Open Access Journals (Sweden)

    Her-Terng Yau

    2013-01-01

    Full Text Available Due to global energy crisis and severe environmental pollution, the photovoltaic (PV system has become one of the most important renewable energy sources. Many previous studies on solar charger integrated system only focus on load charge control or switching Maximum Power Point Tracking (MPPT and charge control modes. This study used two-stage system, which allows the overall portable solar energy charging system to implement MPPT and optimal charge control of Li-ion battery simultaneously. First, this study designs a DC/DC boost converter of solar power generation, which uses variable step size incremental conductance method (VSINC to enable the solar cell to track the maximum power point at any time. The voltage was exported from the DC/DC boost converter to the DC/DC buck converter, so that the voltage dropped to proper voltage for charging the battery. The charging system uses constant current/constant voltage (CC/CV method to charge the lithium battery. In order to obtain the optimum PI charge controller parameters, this study used intelligent algorithm to determine the optimum parameters. According to the simulation and experimental results, the control parameters resulted from PSO have better performance than genetic algorithms (GAs.

  5. Ground Based Synoptic Instrumentation for Solar Observations (Postprint)

    Science.gov (United States)

    2012-03-05

    None are corrected for chromatic aberration . The system overall is diffraction limited for all wavelengths in the tunable range. The magnifier lens...simultaneously corrects for chromatic focus effects and maintains a constant solar diameter throughout the year. The magnifier lens is interchangeable

  6. PSO based PI controller design for a solar charger system.

    Science.gov (United States)

    Yau, Her-Terng; Lin, Chih-Jer; Liang, Qin-Cheng

    2013-01-01

    Due to global energy crisis and severe environmental pollution, the photovoltaic (PV) system has become one of the most important renewable energy sources. Many previous studies on solar charger integrated system only focus on load charge control or switching Maximum Power Point Tracking (MPPT) and charge control modes. This study used two-stage system, which allows the overall portable solar energy charging system to implement MPPT and optimal charge control of Li-ion battery simultaneously. First, this study designs a DC/DC boost converter of solar power generation, which uses variable step size incremental conductance method (VSINC) to enable the solar cell to track the maximum power point at any time. The voltage was exported from the DC/DC boost converter to the DC/DC buck converter, so that the voltage dropped to proper voltage for charging the battery. The charging system uses constant current/constant voltage (CC/CV) method to charge the lithium battery. In order to obtain the optimum PI charge controller parameters, this study used intelligent algorithm to determine the optimum parameters. According to the simulation and experimental results, the control parameters resulted from PSO have better performance than genetic algorithms (GAs).

  7. Advances in graphene-based semiconductor photocatalysts for solar energy conversion: fundamentals and materials engineering

    Science.gov (United States)

    Xie, Xiuqiang; Kretschmer, Katja; Wang, Guoxiu

    2015-08-01

    Graphene-based semiconductor photocatalysis has been regarded as a promising technology for solar energy storage and conversion. In this review, we summarized recent developments of graphene-based photocatalysts, including preparation of graphene-based photocatalysts, typical key advances in the understanding of graphene functions for photocatalytic activity enhancement and methodologies to regulate the electron transfer efficiency in graphene-based composite photocatalysts, by which we hope to offer enriched information to harvest the utmost fascinating properties of graphene as a platform to construct efficient graphene-based composite photocatalysts for solar-to-energy conversion.

  8. A New Fuzzy-Based Maximum Power Point Tracker for a Solar Panel Based on Datasheet Values

    Directory of Open Access Journals (Sweden)

    Ali Kargarnejad

    2013-01-01

    Full Text Available Tracking maximum power point of a solar panel is of interest in most of photovoltaic applications. Solar panel modeling is also very interesting exclusively based on manufacturers data. Knowing that the manufacturers generally give the electrical specifications of their products at one operating condition, there are so many cases in which the specifications in other conditions are of interest. In this research, a comprehensive one-diode model for a solar panel with maximum obtainable accuracy is fully developed only based on datasheet values. The model parameters dependencies on environmental conditions are taken into consideration as much as possible. Comparison between real data and simulations results shows that the proposed model has maximum obtainable accuracy. Then a new fuzzy-based controller to track the maximum power point of the solar panel is also proposed which has better response from speed, accuracy and stability point of view respect to the previous common developed one.

  9. Systematic process development towards high performance transferred thin silicon solar cells based on epitaxially grown absorbers

    Science.gov (United States)

    Murcia Salazar, Clara Paola

    ). First principles modeling, however, predicts that efficiencies of 20+% are achievable with less than 20 mum of c-Si. In addition to a high voltage design, this work reports state of the art epitaxial c-Si solar cell performance and a path towards 20+%-efficient transferred epitaxial solar cells. The design and fabrication approach is based on high open circuit voltage first, high short circuit current second. A first design is a thin solar cell grown on a conductive silicon wafer. This structure allows developing processes to increase bulk lifetime and reduce surface recombination. Important processes that can be used for a transferred solar cell such as increased fill factor (FF) are developed at this stage. A second design is based on the use of a separation layer prior to the solar cell growth. We achieve a comparable performance with the second design. A third design includes the transfer of the solar cell to a secondary substrate. Initial processing development is reported for the transferred solar cells. Improvements in solar cell critical parameters have been characterized with a combination of predictive modeling and solar cell diagnostic tools such as quantum efficiency and voltage measurements. Fabrication processes have been developed to improve solar cell performance. The combination of process development, test structures, systematic fabrication, testing and analysis concludes with a path to high voltage, transferred thin c-Si solar cells towards 20+% efficiencies.

  10. National Solar Radiation Data Base, Vol. 2 - Final Technical Report (1961-1990)

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, E. L.; Marion, W.; Myers, D.; Rymes, M.; Wilcox, S.

    1995-01-01

    This technical report explains the procedures used during the 4-year production of the National Solar Radiation Data Base (NSRDB) (1961-1990). It is the second volume in a two-volume report on the NSRDB. The first volume, User's Guide-National Solar Radiation Data Base, provides the information needed to use the data base products. Volume 2 concentrates on results from the R&D required to producea solar radiation data base that would represent a significant update of a previous data base (SOLMET). More than 90% of the data in the NSRDB were estimated using a model--the Meteorological/Statistical (METSTAT) model. Much of Volume 2 concerns the METSTAT model and the sources of its input data. In addition, it contains results of comparisons of the NSRBD with the previous SOLMET data base.Results of the model evaluations and data base comparisons favor the use of NSRDB data over SOLMET data to select optimum sites and estimate performance for solar energy systems. The report noted that to improve data on solar radiation, 'measured' data need to become the mainstav of future data bases.

  11. Efficiency Investigation of Dye-Sensitized Solar Cells Based on the Zinc Oxide Nanowires

    OpenAIRE

    Ahmad Afifi; Mohammad Kazem Tabatabaei

    2014-01-01

    In this paper, we synthesized ZnO nanowires in dye sensitized solar cells. The nanowires have been fabricated using fast-microwave-hydrothermal process.We verify the effects of different lengths of ZnO nanowires on efficiency and absorptionofdye sensitized solar cells. J–V curves of the fabricated ZnO nanowire-based mercurochrome-sensitized solar cellsindicated that the short-circuit current density wouldincrease with increasing the length of nanowires.We also fabricate more efficient N719-se...

  12. PERFORMANCE OF EVACUATED TUBE SOLAR COLLECTOR USING WATER-BASED TITANIUM OXIDE NANOFLUID

    OpenAIRE

    M. Mahendran; Lee, G C; Sharma, K. V.; A. Shahrani; R. A. Bakar

    2012-01-01

    Experiments are undertaken to determine the efficiency of an evacuated tube solar collector using water-based Titanium Oxide (TiO2) nanofluid at the Pekan Campus (3˚32’ N, 103˚25’ E), Faculty of Mechanical Engineering, University Malaysia Pahang, for the conversion of solar thermal energy. Malaysia lies in the equatorial zone with an average daily solar insolation of more than 900 W/m², which can reach a maximum of 1200 W/m² for most of the year. Traditionally water is pumped through the coll...

  13. Investigation of solar energy utilization in a novel desiccant based air conditioning system

    Energy Technology Data Exchange (ETDEWEB)

    Hurdodan, Ertac; Buyukalaca, Orhan [Department of Energy Systems Engineering, Faculty of Engineering, Osmaniye Korkut Ata University (Turkey)], email: ehurdogan@osmaniye.edu.tr, email: obuyukalaca@osmaniye.edu.tr; Yilmaz, Tuncay; Uckan, Irfan [Department of Mechanical Engineering, Faculty of Engineering and Architecture, Cukurova University (Turkey)], email: tunyil@cu.edu.tr, email: iuckan@cu.edu.tr; Hepbasli, Arif [Department of Mechanical Engineering, College of Engineering, King Saud University (Saudi Arabia)], email: ahepbasli.c@ksu.edu.sa

    2011-07-01

    Desiccant-based air-conditioning systems are an alternative to traditional air conditioning units. They have superior humidity control and are usually used in health care facilities to reduce the airborne transmission of disease. In the present study, an innovative, desiccant-based air-conditioning system was designed and tested in Cukurova University, Adana, Turkey. A model for investigating the use of solar energy in the system was developed. Experimental temperatures throughout the cooling season of 2008 and solar radiation data, measured by the State Meteorological Affairs (DMI) over the period 1986-2006, were utilized in the model. A comparison was made between the results obtained from the model and those from the experiments and it was concluded that solar energy could be utilized in the system. Solar energy also increased the coefficient of performance (COP) of the system by between 50% and 120% and was shown to be a cost-effective way of regenerating the desiccant.

  14. Considerably improved photovoltaic performance of carbon nanotube-based solar cells using metal oxide layers.

    Science.gov (United States)

    Wang, Feijiu; Kozawa, Daichi; Miyauchi, Yuhei; Hiraoka, Kazushi; Mouri, Shinichiro; Ohno, Yutaka; Matsuda, Kazunari

    2015-02-18

    Carbon nanotube-based solar cells have been extensively studied from the perspective of potential application. Here we demonstrated a significant improvement of the carbon nanotube solar cells by the use of metal oxide layers for efficient carrier transport. The metal oxides also serve as an antireflection layer and an efficient carrier dopant, leading to a reduction in the loss of the incident solar light and an increase in the photocurrent, respectively. As a consequence, the photovoltaic performance of both p-single-walled carbon nanotube (SWNT)/n-Si and n-SWNT/p-Si heterojunction solar cells using MoOx and ZnO layers is improved, resulting in very high photovoltaic conversion efficiencies of 17.0 and 4.0%, respectively. These findings regarding the use of metal oxides as multifunctional layers suggest that metal oxide layers could improve the performance of various electronic devices based on carbon nanotubes.

  15. Observer-Based Bilinear Control of First-Order Hyperbolic PDEs: Application to the Solar Collector

    KAUST Repository

    Mechhoud, Sarra

    2015-12-18

    In this paper, we investigate the problem of bilinear control of a solar collector plant using the available boundary and solar irradiance measurements. The solar collector is described by a first-order 1D hyperbolic partial differential equation where the pump volumetric flow rate acts as the plant control input. By combining a boundary state observer and an internal energy-based control law, a nonlinear observer based feedback controller is proposed. With a feed-forward control term, the effect of the solar radiation is cancelled. Using the Lyapunov approach we prove that the proposed control guarantees the global exponential stability of both the plant and the tracking error. Simulation results are provided to illustrate the performance of the proposed method.

  16. Relationship between open-circuit voltage in Cu(In,Ga)Se{sub 2} solar cell and peak position of (220/204) preferred orientation near its absorber surface

    Energy Technology Data Exchange (ETDEWEB)

    Chantana, J., E-mail: jakapan@fc.ritsumei.ac.jp; Minemoto, T. [Department of Electrical and Electronic Engineering, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga 525-8577 (Japan); Watanabe, T.; Teraji, S.; Kawamura, K. [Environment and Energy Research Center, Nitto Denko Corporation, 2-8 Yamadaoka, Suita, Osaka 565-0871 (Japan)

    2013-11-25

    Cu(In,Ga)Se{sub 2} (CIGS) absorbers with various Ga/III, Ga/(In+Ga), profiles are prepared by the so-called “multi-layer precursor method” using multi-layer co-evaporation of material sources. It is revealed that open-circuit voltage (V{sub OC}) of CIGS solar cell is primarily dependent on averaged Ga/III near the surface of its absorber. This averaged Ga/III is well predicted by peak position of (220/204) preferred orientation of CIGS film near its surface investigated by glancing-incidence X-ray diffraction with 0.1° incident angle. Finally, the peak position of (220/204) preferred orientation is proposed as a measure of V{sub OC} before solar cell fabrication.

  17. CuInGaS2 photocathodes treated with SbX3 (X  =  Cl, I): the effect of the halide on solar water splitting performance

    Science.gov (United States)

    Guijarro, Néstor; Prévot, Mathieu S.; Johnson, Melissa; Yu, Xiaoyun; Bourée, Wiktor S.; Jeanbourquin, Xavier A.; Bornoz, Pauline; Le Formal, Florian; Sivula, Kevin

    2017-02-01

    The realization of photoelectrochemical tandem cells for efficient solar-to-hydrogen energy conversion is currently impeded by the lack of inexpensive, stable, and efficient photocathodes. The family of sulfide chalcopyrites (CuIn x Ga1-x S2) has recently demonstrated a remarkable stability and performance even when prepared by solution-based routes that potentially lower the cost of fabrication. However, the photovoltage delivered by the photocathodes is still well-below the attainable values, a classical limitation linked to a large density of surface states in these materials. In the present work, we show that the identity of halide present during the growth of the solution-processed CuIn0.3Ga0.7S2 (CIGS) thin-films governs the overall performance by directing the crystal growth and the passivation of surface states. Replacing chlorine by iodine leads to CIGS photocathodes that deliver photocurrents of 5 mA cm-2 (at 0 V versus RHE) and a turn-on voltage of 0.5 V versus RHE without charge extracting overlayer nor any sign of deterioration during stability test.

  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. 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

  20. Preparation of a Textile-Based Dye-Sensitized Solar Cell

    OpenAIRE

    Klaus Opwis; Jochen Stefan Gutmann; Ana Rosa Lagunas Alonso; Maria Jesus Rodriguez Henche; Mikel Ezquer Mayo; Fanny Breuil; Enrico Leonardi; Luca Sorbello

    2016-01-01

    Solar energy conversion is an object of continuous research, focusing on improving the energy efficiency as well as the structure of photovoltaic cells. With efficiencies continuously increasing, state-of-the-art PV cells offer a good solution to harvest solar energy. However, they are still lacking the flexibility and conformability to be integrated into common objects or clothing. Moreover, many sun-exposed surface areas are textile-based such as garments, tents, truck coverings, boat sails...

  1. Updated solution to the solar neutrino problem based on non-standard neutrino interactions

    CERN Document Server

    Guzzo, M M; Nunokawa, H

    2001-01-01

    We present an updated version of the solution to the solar neutrino problem based on non-standard flavor changing neutrino interactions (FCNI) and non-universal flavor diagonal neutrino interactions (FDNI). We find a good fit not only to the total rates measured by all solar neutrino experiments but also to the day-night and seasonal variations of the event rate, as well as the recoil electron energy spectrum measured by the SuperKamiokande collaboration.

  2. Residential Solar-Based Seasonal Thermal Storage Systems in Cold Climates: Building Envelope and Thermal Storage

    OpenAIRE

    Alexandre Hugo; Radu Zmeureanu

    2012-01-01

    The reduction of electricity use for heating and domestic hot water in cold climates can be achieved by: (1) reducing the heating loads through the improvement of the thermal performance of house envelopes, and (2) using solar energy through a residential solar-based thermal storage system. First, this paper presents the life cycle energy and cost analysis of a typical one-storey detached house, located in Montreal, Canada. Simulation of annual energy use is performed using the TRNSYS softwar...

  3. Photoelectrochemical Characterizations Of ZnO Based Dye-Sensitized Solar Cell

    OpenAIRE

    Baviskar, P K; D. B. Salunkhe; Babasaheb R. Sankapal

    2010-01-01

    Dye-sensitized solar cells (DSSCs) based on organic dyes adsorbed on nano-particles of zinc oxide (ZnO) electrode have received considerable attention because of their high incident solar light to power conversion efficiency and low production cost. Multiple organic dyes with different chemical structure have been developed so far. They have been tested for their photovoltaic performances with combinations of different photo-anodes. In order to produce efficient DSSCs, it is imperative to dev...

  4. Highly efficient solar cells based on poly(3-butylthiophene) nanowires.

    Science.gov (United States)

    Xin, Hao; Kim, Felix Sunjoo; Jenekhe, Samson A

    2008-04-23

    Poly(3-butylthiophene) (P3BT) nanowires, prepared by solution-phase self-assembly, have been used to construct highly efficient P3BT/fullerene nanocomposite solar cells. The fullerene/P3BT nanocomposite films showed an electrically bicontinuous nanoscale morphology with average field-effect hole mobilities as high as 8.0 x 10(-3) cm2/Vs due to the interconnected P3BT nanowire network revealed by TEM and AFM imaging. The power conversion efficiency of fullerene/P3BT nanowire devices was 3.0% (at 100 mW/cm2, AM1.5) in air and found to be identical with our similarly tested fullerene/poly(3-hexylthiophene) photovoltaic cells. This discovery expands the scope of promising materials and architectures for efficient bulk heterojunction solar cells.

  5. A Nitinol-Based Solar Array Deployment Mechanism

    Science.gov (United States)

    Choi, Shin John; Lu, Chia-Ao; Feland, John

    1996-01-01

    This document describes a simple, light weight, and scalable mechanism capable of deploying flexible or rigid substrate solar arrays that have been configured in an accordion-like folding scheme. This mechanism is unique in that it incorporates a Shape Memory Alloy (SMA) actuator made of Nitinol. This paper documents the design of the mechanism in full detail while offering to designers a foundation of knowledge by which they can develop future applications with SMA's.

  6. A power pack based on organometallic perovskite solar cell and supercapacitor.

    Science.gov (United States)

    Xu, Xiaobao; Li, Shaohui; Zhang, Hua; Shen, Yan; Zakeeruddin, Shaik M; Graetzel, Michael; Cheng, Yi-Bing; Wang, Mingkui

    2015-02-24

    We present an investigation on a power pack combining a CH3NH3PbI3-based solar cell with a polypyrrole-based supercapacitor and evaluate its performance as an energy pack. The package achieved an energy storage efficiency of 10%, which is much higher than that of other systems combining a PV cell with a supercapacitor. We find a high output voltage of 1.45 V for the device under AM 1.5G illumination when the CH3NH3PbI3-based solar cell is connected in series with a polypyrrole-based supercapacitor. This system affords continuous output of electric power by using CH3NH3PbI3-based solar cell as an energy source mitigating transients caused by light intensity fluctuations or the diurnal cycle.

  7. Prediction of solar cycle based on the invariant

    Institute of Scientific and Technical Information of China (English)

    LIU Shijun; YU Xiaoding; CHEN Yongyi

    2003-01-01

    A new method of predicting solar activities has been introduced in this paper. The method can predict both the occurrence time and the maximum number of sunspot at the same time. By studying the variation of sunspot, we find that the combination of the several variables was nearly invariable during the entire solar cycles, as called invariant. And just only by determining the start time of a cycle, we can predict the occurrence time of cycle's peak value accurately. Furthermore, according to observational data of the sunspot cycles, it showed that the sunspot maximum number has correlation not only with the prophase variety of the number in the cycle but also with the anaphase of the previous period. So we can introduce an equivalent regression coefficient, which can dynamically self-adapt to different cycle lengths, and effectively solve the inconsistency between the accuracy and the lead-time of the forecast. It can guarantee the satisfied accuracy and effectively increases the lead-time of the forecast. This method can predict the maximum sunspot number for solar cycle at the approximate half rise of the period. This method predicts that the occurrence time of the maximum sunspot number for cycle 24 will be in January 2011.

  8. Vegetable-based dye-sensitized solar cells.

    Science.gov (United States)

    Calogero, Giuseppe; Bartolotta, Antonino; Di Marco, Gaetano; Di Carlo, Aldo; Bonaccorso, Francesco

    2015-05-21

    There is currently a large effort to improve the performance of low cost renewable energy devices. Dye-sensitized solar cells (DSSCs) are emerging as one of the most promising low cost photovoltaic technologies, addressing "secure, clean and efficient solar energy conversion". Vegetable dyes, extracted from algae, flowers, fruit and leaves, can be used as sensitizers in DSSCs. Thus far, anthocyanin and betalain extracts together with selected chlorophyll derivatives are the most successful vegetable sensitizers. This review analyses recent progress in the exploitation of vegetable dyes for solar energy conversion and compares them to the properties of synthetic dyes. We provide an in-depth discussion on the main limitation of cell performance e.g. dye degradation, effective electron injection from the dye into the conduction band of semiconducting nanoparticles, such as titanium dioxide and zinc oxide, outlining future developments for the use of vegetable sensitizers in DSSCs. We also discuss the cost of vegetable dyes and how their versatility can boost the advancement of new power management solutions, especially for their integration in living environments, making the practical application of such systems economically viable. Finally, we present our view on future prospects in the development of synthetic analogues of vegetable dyes as sensitizers in DSSCs.

  9. Limitation of Ground-based Estimates of Solar Irradiance Due to Atmospheric Variations

    Science.gov (United States)

    Wen, Guoyong; Cahalan, Robert F.; Holben, Brent N.

    2003-01-01

    The uncertainty in ground-based estimates of solar irradiance is quantitatively related to the temporal variability of the atmosphere's optical thickness. The upper and lower bounds of the accuracy of estimates using the Langley Plot technique are proportional to the standard deviation of aerosol optical thickness (approx. +/- 13 sigma(delta tau)). The estimates of spectral solar irradiance (SSI) in two Cimel sun photometer channels from the Mauna Loa site of AERONET are compared with satellite observations from SOLSTICE (Solar Stellar Irradiance Comparison Experiment) on UARS (Upper Atmospheric Research Satellite) for almost two years of data. The true solar variations related to the 27-day solar rotation cycle observed from SOLSTICE are about 0.15% at the two sun photometer channels. The variability in ground-based estimates is statistically one order of magnitude larger. Even though about 30% of these estimates from all Level 2.0 Cimel data fall within the 0.4 to approx. 0.5% variation level, ground-based estimates are not able to capture the 27-day solar variation observed from SOLSTICE.

  10. Solar-thermal conversion and thermal energy storage of graphene foam-based composite

    KAUST Repository

    Zhang, Lianbin

    2016-07-11

    Among various utilizations of solar energy, solar-thermal conversion has recently gained renewed research interest due to its extremely high energy efficiency. However, one limiting factor common to all solar-based energy conversion technologies is the intermittent nature of solar irradiation, which makes them unable to stand-alone to satisfy continuous energy need. Herein, we report a three-dimensional (3D) graphene foam and phase change material (PCM) composite for the seamlessly combined solar-thermal conversion and thermal storage for sustained energy release. The composite is obtained by infiltrating the 3D graphene foam with a commonly used PCM, paraffin wax. The high macroporosity and low density of the graphene foam allow for high weight fraction of the PCM to be incorporated, which enhances heat storage capacity of the composite. The interconnected graphene sheets in the composite provide (1) the solar-thermal conversion capability, (2) high thermal conductivity and (3) form stability of the composite. Under light irradiation, the composite effectively collects and converts the light energy into thermal energy, and the converted thermal energy is stored in the PCM and released in an elongated period of time for sustained utilization. This study provides a promising route for sustainable utilization of solar energy.

  11. Solar-thermal conversion and thermal energy storage of graphene foam-based composites.

    Science.gov (United States)

    Zhang, Lianbin; Li, Renyuan; Tang, Bo; Wang, Peng

    2016-08-14

    Among various utilizations of solar energy, solar-thermal conversion has recently gained renewed research interest due to its extremely high energy efficiency. However, one limiting factor common to all solar-based energy conversion technologies is the intermittent nature of solar irradiation, which makes them unable to stand-alone to satisfy the continuous energy need. Herein, we report a three-dimensional (3D) graphene foam and phase change material (PCM) composite for the seamlessly combined solar-thermal conversion and thermal storage for sustained energy release. The composite is obtained by infiltrating the 3D graphene foam with a commonly used PCM, paraffin wax. The high macroporosity and low density of the graphene foam allow for high weight fraction of the PCM to be incorporated, which enhances the heat storage capacity of the composite. The interconnected graphene sheets in the composite provide (1) the solar-thermal conversion capability, (2) high thermal conductivity and (3) form stability of the composite. Under light irradiation, the composite effectively collects and converts the light energy into thermal energy, and the converted thermal energy is stored in the PCM and released in an elongated period of time for sustained utilization. This study provides a promising route for sustainable utilization of solar energy.

  12. Gold nanoparticles enhanced photocurrent in nanostructure-based bulk heterojunction solar cell

    Science.gov (United States)

    Long, Gen; Ching, Levine; Saqodi, Mostafa; Xu, Huizhong

    2016-04-01

    In this paper, we report a first hand study of enhanced photocurrent observed in nanostructure-based bulk heterojunction solar cell due to introduction of Au nanoparticles. The bulk heterojunction solar cell was fabricated using chemically synthesized narrow gap, IV-VI group semiconductor nanoparticles (PbS, ~3 nm), wide gap semiconductor ZnO nanowires (~1 μm length, ~50 nm diameter), and gold nanoparticles (~20 nm), by spin-coating method in N2-filled glove box. We have demonstrated that such a bulk heterojunction solar cell can be incorporated with metal nanoparticles (Au) to enhance solar device performance. Three types of solar cell devices were studied. An enhancement in the photocurrent due to introduction of Au nanoparticles was observed, compared to solar cell device without Au nanoparticles. The power conversion efficiency was also increased, possibly due to the plasmonic effects from Au nanoparticles. The fabrication procedures can be readily extended to other nanomaterial systems. Further optimization in the fabrication would be needed to realize high-efficient, stable solar cell devices.

  13. Residential Solar-Based Seasonal Thermal Storage Systems in Cold Climates: Building Envelope and Thermal Storage

    Directory of Open Access Journals (Sweden)

    Alexandre Hugo

    2012-10-01

    Full Text Available The reduction of electricity use for heating and domestic hot water in cold climates can be achieved by: (1 reducing the heating loads through the improvement of the thermal performance of house envelopes, and (2 using solar energy through a residential solar-based thermal storage system. First, this paper presents the life cycle energy and cost analysis of a typical one-storey detached house, located in Montreal, Canada. Simulation of annual energy use is performed using the TRNSYS software. Second, several design alternatives with improved thermal resistance for walls, ceiling and windows, increased overall air tightness, and increased window-to-wall ratio of South facing windows are evaluated with respect to the life cycle energy use, life cycle emissions and life cycle cost. The solution that minimizes the energy demand is chosen as a reference house for the study of long-term thermal storage. Third, the computer simulation of a solar heating system with solar thermal collectors and long-term thermal storage capacity is presented. Finally, the life cycle cost and life cycle energy use of the solar combisystem are estimated for flat-plate solar collectors and evacuated tube solar collectors, respectively, for the economic and climatic conditions of this study.

  14. Performance Evaluation of a Nanofluid-Based Direct Absorption Solar Collector with Parabolic Trough Concentrator

    Directory of Open Access Journals (Sweden)

    Guoying Xu

    2015-12-01

    Full Text Available Application of solar collectors for hot water supply, space heating, and cooling plays a significant role in reducing building energy consumption. For conventional solar collectors, solar radiation is absorbed by spectral selective coating on the collectors’ tube/plate wall. The poor durability of the coating can lead to an increased manufacturing cost and unreliability for a solar collector operated at a higher temperature. Therefore, a novel nanofluid-based direct absorption solar collector (NDASC employing uncoated collector tubes has been proposed, and its operating characteristics for medium-temperature solar collection were theoretically and experimentally studied in this paper. CuO/oil nanofluid was prepared and used as working fluid of the NDASC. The heat-transfer mechanism of the NDASC with parabolic trough concentrator was theoretically evaluated and compared with a conventional indirect absorption solar collector (IASC. The theoretical analysis results suggested that the fluid’s temperature distribution in the NDASC was much more uniform than that in the IASC, and an enhanced collection efficiency could be achieved for the NDASC operated within a preferred working temperature range. To demonstrate the feasibility of the proposed NDASC, experimental performances of an NDASC and an IASC with the same parabolic trough concentrator were furthermore evaluated and comparatively discussed.

  15. Solar array design based on shadow analysis for increasing net energy collection in a competition vehicle

    Science.gov (United States)

    Osorio-Gómez, Gilberto; Mejía-Gutiérrez, Ricardo; Suárez-Castañeda, Nicolás; Gil-Herrera, Ana; Barrera-Velásquez, Jorge

    2015-01-01

    Photovoltaic (PV) applications such as in the architectural, automotive, and aerospace industries face design contradictions because they are expected to produce a lot of energy but are constrained by available area, surface shape, incident irradiance, shadows, and other aspects that have a negative influence on the energy produced by the solar panel. Solar competition vehicles are some of these challenging PV applications. The design of such solar arrays needs to consider efficiency evaluation in order to optimize space; it is difficult not to install solar modules in areas impacted by shadows. A design procedure for a solar array configuration based on shadow analysis for competition vehicles is presented. The principle is that shadows in moving objects can be simulated, since the vehicle, the earth and the sun are are moving in semipredictable patterns, thus net energy collection can be forecast. The case study presented is the solar array design of a vehicle that participated in the World Solar Challenge 2013. The obtained results illustrate how the employment of the procedure gives insights on important aspects to consider and also delivers qualitative and quantitative information for decision making. In addition, the experience in competition highlights some issues to be considered, modified, or improved in further vehicle designs.

  16. Effect of electrodeposition potential on composition and morphology of CIGS absorber thin film

    Indian Academy of Sciences (India)

    N D Sang; P H Quang; L T Tu; D T B Hop

    2013-08-01

    CuInGaSe (CIGS) thin films were deposited on Mo/soda-lime glass substrates by electrodeposition at different potentials ranging from −0.3 to −1.1 V vs Ag/AgCl. Cyclic voltammetry (CV) studies of unitary Cu, Ga, In and Se systems, binary Cu–Se, Ga–Se and In–Se systems and quaternary Cu–In–Ga–Se were carried out to understand the mechanism of deposition of each constituent. Concentration of the films was determined by energy dispersive spectroscopy. Structure and morphology of the films were characterized by X-ray diffraction and scanning electron microscope. The underpotential deposition mechanism of Cu–Se and In–Se phases was observed in voltammograms of binary and quaternary systems. Variation in composition with applied potentials was explained by cyclic voltammetry (CV) data. A suitable potential range from −0.8 to −1.0 V was found for obtaining films with desired and stable stoichiometry. In the post-annealing films, chalcopyrite structure starts forming in the samples deposited at −0.5 V and grows on varying the applied potential towards negative direction. By adjusting the composition of electrolyte, we obtained the desired stoichiometry of Cu(In0.7Ga0.3)Se2.

  17. Long-term performance data and analysis of CIS/CIGS modules deployed outdoors

    Science.gov (United States)

    del Cueto, J. A.; Rummel, S.; Kroposki, B.; Anderberg, A.

    2008-08-01

    The long-term performance data of copper indium diselenide (CIS) and gallium-alloyed CIS (CIGS) photovoltaic (PV) modules are investigated to assess the reliability of this technology. We study and report on numerous PV modules acquired from two manufacturers (A and B), deployed at NREL's outdoor test facility (OTF) in various configurations in the field: some are free standing, loaded with a fixed resistance and periodically tested indoors at STC; other modules are connected to data acquisition systems with their performance continuously monitored. Performance is characterized using current-voltage (I-V) measurements obtained either at standard test conditions or under real-time monitoring conditions: the power parameters plus other factors relating to quality like diode quality factors or series resistance are analyzed for changes against time. Using standard diode analysis to determine the sources of degradation indicates that CIS modules can exhibit between moderate and negligible degradation, with the dominant loss mode being fill factor declines along with decreases in open-circuit voltage, for illumination intensities near 1-sun. At lower intensities, current losses can appear appreciable. The real-time performance data also indicate that fill factor loss is the primary degradation mode, generally as a result of increases in series resistance.

  18. Long-term performance analysis of CIGS thin-film PV modules

    Science.gov (United States)

    Dhere, Neelkanth G.; Kaul, Ashwani; Pethe, Shirish A.

    2011-09-01

    Current accelerated qualification tests of photovoltaic (PV) modules mostly assist in avoiding infant mortality but can neither duplicate changes occurring in the field nor can predict useful lifetime. Therefore, outdoor monitoring of fielddeployed thin-film PV modules was undertaken at FSEC with goals of assessing their performance in hot and humid climate under high system voltage operation and to correlate the PV performance with the meteorological parameters. Significant and comparable degradation rate of -5.13% and -4.5% per year was found by PV USA type regression analysis for the positive and negative strings respectively of 40W glass-to-glass CIGS thin-film PV modules in the hot and humid climate of Florida. With the current-voltage measurements it was found that the performance degradation within the PV array was mainly due to a few (8-12%) modules having a substantially high degradation. The remaining modules within the array continued to show reasonable performance (>96% of the rated power after ~ 4years).

  19. Harnessing Sun’s Energy with Quantum Dots Based Next Generation Solar Cell

    Science.gov (United States)

    Halim, Mohammad A.

    2012-01-01

    Our energy consumption relies heavily on the three components of fossil fuels (oil, natural gas and coal) and nearly 83% of our current energy is consumed from those sources. The use of fossil fuels, however, has been viewed as a major environmental threat because of their substantial contribution to greenhouse gases which are responsible for increasing the global average temperature. Last four decades, scientists have been searching for alternative sources of energy which need to be environmentally clean, efficient, cost-effective, renewable, and sustainable. One of the promising sustainable sources of energy can be achieved by harnessing sun energy through silicon wafer, organic polymer, inorganic dye, and quantum dots based solar cells. Among them, quantum dots have an exceptional property in that they can excite multiple electrons using only one photon. These dots can easily be synthesized, processed in solution, and incorporated into solar cell application. Interestingly, the quantum dots solar cells can exceed the Shockley-Queisser limit; however, it is a great challenge for other solar cell materials to exceed the limit. Theoretically, the quantum dots solar cell can boost the power conversion efficiency up to 66% and even higher to 80%. Moreover, in changing the size of the quantum dots one can utilize the Sun’s broad spectrum of visible and infrared ranges. This review briefly overviews the present performance of different materials-based solar cells including silicon wafer, dye-sensitized, and organic solar cells. In addition, recent advances of the quantum dots based solar cells which utilize cadmium sulfide/selenide, lead sulfide/selenide, and new carbon dots as light harvesting materials has been reviewed. A future outlook is sketched as to how one could improve the efficiency up to 10% from the current highest efficiency of 6.6%.

  20. Harnessing Sun's Energy with Quantum Dots Based Next Generation Solar Cell.

    Science.gov (United States)

    Halim, Mohammad A

    2012-12-27

    Our energy consumption relies heavily on the three components of fossil fuels (oil, natural gas and coal) and nearly 83% of our current energy is consumed from those sources. The use of fossil fuels, however, has been viewed as a major environmental threat because of their substantial contribution to greenhouse gases which are responsible for increasing the global average temperature. Last four decades, scientists have been searching for alternative sources of energy which need to be environmentally clean, efficient, cost-effective, renewable, and sustainable. One of the promising sustainable sources of energy can be achieved by harnessing sun energy through silicon wafer, organic polymer, inorganic dye, and quantum dots based solar cells. Among them, quantum dots have an exceptional property in that they can excite multiple electrons using only one photon. These dots can easily be synthesized, processed in solution, and incorporated into solar cell application. Interestingly, the quantum dots solar cells can exceed the Shockley-Queisser limit; however, it is a great challenge for other solar cell materials to exceed the limit. Theoretically, the quantum dots solar cell can boost the power conversion efficiency up to 66% and even higher to 80%. Moreover, in changing the size of the quantum dots one can utilize the Sun's broad spectrum of visible and infrared ranges. This review briefly overviews the present performance of different materials-based solar cells including silicon wafer, dye-sensitized, and organic solar cells. In addition, recent advances of the quantum dots based solar cells which utilize cadmium sulfide/selenide, lead sulfide/selenide, and new carbon dots as light harvesting materials has been reviewed. A future outlook is sketched as to how one could improve the efficiency up to 10% from the current highest efficiency of 6.6%.

  1. Harnessing Sun’s Energy with Quantum Dots Based Next Generation Solar Cell

    Directory of Open Access Journals (Sweden)

    Mohammad A. Halim

    2012-12-01

    Full Text Available Our energy consumption relies heavily on the three components of fossil fuels (oil, natural gas and coal and nearly 83% of our current energy is consumed from those sources. The use of fossil fuels, however, has been viewed as a major environmental threat because of their substantial contribution to greenhouse gases which are responsible for increasing the global average temperature. Last four decades, scientists have been searching for alternative sources of energy which need to be environmentally clean, efficient, cost-effective, renewable, and sustainable. One of the promising sustainable sources of energy can be achieved by harnessing sun energy through silicon wafer, organic polymer, inorganic dye, and quantum dots based solar cells. Among them, quantum dots have an exceptional property in that they can excite multiple electrons using only one photon. These dots can easily be synthesized, processed in solution, and incorporated into solar cell application. Interestingly, the quantum dots solar cells can exceed the Shockley-Queisser limit; however, it is a great challenge for other solar cell materials to exceed the limit. Theoretically, the quantum dots solar cell can boost the power conversion efficiency up to 66% and even higher to 80%. Moreover, in changing the size of the quantum dots one can utilize the Sun’s broad spectrum of visible and infrared ranges. This review briefly overviews the present performance of different materials-based solar cells including silicon wafer, dye-sensitized, and organic solar cells. In addition, recent advances of the quantum dots based solar cells which utilize cadmium sulfide/selenide, lead sulfide/selenide, and new carbon dots as light harvesting materials has been reviewed. A future outlook is sketched as to how one could improve the efficiency up to 10% from the current highest efficiency of 6.6%.

  2. 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

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

  3. Application of Ce3+ single-doped complexes as solar spectral downshifters for enhancing photoelectric conversion efficiencies of a-Si-based solar cells

    Science.gov (United States)

    Song, Pei; Jiang, Chun

    2013-05-01

    The effect on photoelectric conversion efficiency of an a-Si-based solar cell by applying a solar spectral downshifter of rare earth ion Ce3+ single-doped complexes including yttrium aluminum garnet Y3Al5O12 single crystals, nanostructured ceramics, microstructured ceramics and B2O3-SiO2-Gd2O3-BaO glass is studied. The photoluminescence excitation spectra in the region 360-460 nm convert effectively into photoluminescence emission spectra in the region 450-550 nm where a-Si-based solar cells exhibit a higher spectral response. When these Ce3+ single-doped complexes are placed on the top of an a-Si-based solar cell as precursors for solar spectral downshifting, theoretical relative photoelectric conversion efficiencies of nc-Si:H and a-Si:H solar cells approach 1.09-1.13 and 1.04-1.07, respectively, by means of AMPS-1D numerical modeling, potentially benefiting an a-Si-based solar cell with a photoelectric efficiency improvement.

  4. Salicylic Acid-Based Organic Dyes Acting as the Photosensitizer for Solar Cells.

    Science.gov (United States)

    Hong, Sungjun; Park, Jae-Hyeong; Han, Ah-Reum; Ko, Kwan-Woo; Eom, Jin Hee; Namgoong, Sung Keon; Lo, Alvie S V; Gordon, Keith C; Yoon, Sungho; Han, Chi-Hwan

    2016-05-01

    A D-π-A metal-free organic dye, featuring salicylic acid as a novel acceptor/anchoring unit, has been designed, synthesized and applied to dye-sensitized solar cell. The detailed photophysical, electrochemical, photovoltaic and sensitizing properties of the organic dye were investigated, in addition to the computational studies of the dye and dye-(TiO2)6 system. A solar cell device using this new organic dye as a sensitizer produced a solar to electric power conversion efficiency (PCE) of 3.49% (J(sc) = 6.69 mAcm-2, V(oc) = 0.74 V and ff = 0.70) under 100 mWcm(-2) simulated AM 1.5 G solar irradiation, demonstrating that the salicylic acid-based organic dye is a suitable alternative to currently used organometallic dyes.

  5. Design optimization of thin-film/wafer-based tandem junction solar cells using analytical modeling

    Science.gov (United States)

    Davidson, Lauren; Toor, Fatima

    2016-03-01

    Several research groups are developing solar cells of varying designs and materials that are high efficiency as well as cost competitive with the single junction silicon (Si) solar cells commercially produced today. One of these solar cell designs is a tandem junction solar cell comprised of perovskite (CH3NH3PbI3) and silicon (Si). Loper et al.1 was able to create a 13.4% efficient tandem cell using a perovskite top cell and a Si bottom cell, and researchers are confident that the perovskite/Si tandem cell can be optimized in order to reach higher efficiencies without introducing expensive manufacturing processes. However, there are currently no commercially available software capable of modeling a tandem cell that is based on a thin-film based bottom cell and a wafer-based top cell. While PC1D2 and SCAPS3 are able to model tandem cells comprised solely of thin-film absorbers or solely of wafer-based absorbers, they result in convergence errors if a thin-film/wafer-based tandem cell, such as the perovskite/ Si cell, is modeled. The Matlab-based analytical model presented in this work is capable of modeling a thin-film/wafer-based tandem solar cell. The model allows a user to adjust the top and bottom cell parameters, such as reflectivity, material bandgaps, donor and acceptor densities, and material thicknesses, in order to optimize the short circuit current, open circuit voltage, and quantum efficiency of the tandem solar cell. Using the Matlab-based analytical model, we were able optimize a perovskite/Si tandem cell with an efficiency greater than 30%.

  6. Carbon Nanotube-Conducting Polymer Composites Based Solar Cells

    Institute of Scientific and Technical Information of China (English)

    Prakash; R.Somani; M.Umeno

    2007-01-01

    1 Results Combination of carbon nanotubes (CN) with polymers is important for application towards value added composites,solar cells,fuel cells etc.Especially interesting is the combination of CN with π-conjugated polymers because of the potential interaction between the highly delocalized π-electrons of the CN and the π-electrons correlated with the lattice of polymer skeleton.Efficient exciton dissociation due to electron transfer from the photoexcited polymer to CN is of interest for photovoltaic app...

  7. Controllable design of solid-state perovskite solar cells by SCAPS device simulation

    Science.gov (United States)

    Tan, Kai; Lin, Peng; Wang, Gang; Liu, Yan; Xu, Zongchang; Lin, Yixin

    2016-12-01

    The highest power conversion efficiency (PCE) of solid-state perovskite solar cells (ssPSCs) has achieved 20.1% recently. There is reason to believe that ssPSCs is a strong competitor with silicon and CIGS solar cells in photovoltaic field. The deep understanding of operation mechanism of ssPSCs is essential and required to furtherly improve device performance. The configuration and excition type are similar to inorganic semiconductor solar cells. Therefore, Solar Cell Capacitance Simulator (SCAPS), a device simulator widely using in inorganic solar cells, was employed to controllably design ssPSCs. The validity of device simulation was verified by comparing with real devices from reported literatures. The influence of absorber thickness on device property was discussed, which indicate that it exists an optimal thickness range. Two hypothetical interface layers, TiO2/perovskite layer and perovskite/HTM layer, were introduced into the construction model to consider the effects of interfaces defect density on device performance. It revealed TiO2/perovskite has stronger impact than perovskite/HTM, because higher excess carrier density existing at TiO2/perovskite will cause more recombination rate. In addition, hole transport materials (HTM) parameters, hole mobility and acceptor density, were chosen to study the impact of HTM characteristics on PCE. The analysis illuminate that the design of HTM layer should balance hole mobility and acceptor density. Meanwhile, different HTM candidates were selected and replaced typical HTM layer. The discussion about the function of candidates on solar cells performance demonstrated that a thiophene group hole-transporting polymer (PTAA) and a copper-based conductor (CuI) both have relatively high PCE, which is due to their wide bandgap, high conductivity, and better chemical interaction with perovskite absorber.

  8. Numerical Investigation of Nanofluid-based Solar Collectors

    Science.gov (United States)

    Karami, M.; Raisee, M.; Delfani, S.

    2014-08-01

    Solar thermal collectors are applicable in the water heating or space conditioning systems. Due to the low efficiency of the conventional collectors, some suggestions have been presented for improvement in the collector efficiency. Adding nanoparticles to the working fluid in direct absorption solar collector, which has been recently proposed, leads to improvement in the working fluid thermal and optical properties such as thermal conductivity and absorption coefficient. This results certainly in collector efficiency enhancement. In this paper, the radiative transfer and energy equations are numerically solved. Due to laminar and fully developed flow in the collector, the velocity profile is assumed to be parabolic. As can be observed from the results, outlet temperature of collector is lower than that obtained using uniform velocity profile. Furthermore, a suspension of carbon nanohorns in the water is used as the working fluid in the model and its effect on the collector efficiency is investigated. It was found that the presence of carbon nanohorns increases the collector efficiency by about 17% compared to a conventional flat-plate collector. In comparison with the mixture of water and aluminium nanoparticles, a quite similar efficiency is obtained using very lower concentration of carbon nanohorns in the water.

  9. EffiCiency and Safety of an eLectronic cigAreTte (ECLAT as tobacco cigarettes substitute: a prospective 12-month randomized control design study.

    Directory of Open Access Journals (Sweden)

    Pasquale Caponnetto

    Full Text Available BACKGROUND: Electronic cigarettes (e-cigarettes are becoming increasingly popular with smokers worldwide. Users report buying them to help quit smoking, to reduce cigarette consumption, to relieve tobacco withdrawal symptoms, and to continue having a 'smoking' experience, but with reduced health risks. Research on e-cigarettes is urgently needed in order to ensure that the decisions of regulators, healthcare providers and consumers are based on science. Methods ECLAT is a prospective 12-month randomized, controlled trial that evaluates smoking reduction/abstinence in 300 smokers not intending to quit experimenting two different nicotine strengths of a popular e-cigarette model ('Categoria'; Arbi Group Srl, Italy compared to its non-nicotine choice. GroupA (n = 100 received 7.2 mg nicotine cartridges for 12 weeks; GroupB (n = 100, a 6-week 7.2 mg nicotine cartridges followed by a further 6-week 5.4 mg nicotine cartridges; GroupC (n = 100 received no-nicotine cartridges for 12 weeks. The study consisted of nine visits during which cig/day use and exhaled carbon monoxide (eCO levels were measured. Smoking reduction and abstinence rates were calculated. Adverse events and product preferences were also reviewed. RESULTS: Declines in cig/day use and eCO levels were observed at each study visits in all three study groups (p<0.001 vs baseline, with no consistent differences among study groups. Smoking reduction was documented in 22.3% and 10.3% at week-12 and week-52 respectively. Complete abstinence from tobacco smoking was documented in 10.7% and 8.7% at week-12 and week-52 respectively. A substantial decrease in adverse events from baseline was observed and withdrawal symptoms were infrequently reported during the study. Participants' perception and acceptance of the product under investigation was satisfactory. CONCLUSION: In smokers not intending to quit, the use of e-cigarettes, with or without nicotine, decreased cigarette consumption

  10. Solar Cells Based on Inks of n-Type Colloidal Quantum Dots

    KAUST Repository

    Ning, Zhijun

    2014-10-28

    © 2014 American Chemical Society. New inorganic ligands including halide anions have significantly accelerated progress in colloidal quantum dot (CQD) photovoltaics in recent years. All such device reports to date have relied on halide treatment during solid-state ligand exchanges or on co-treatment of long-aliphatic-ligand-capped nanoparticles in the solution phase. Here we report solar cells based on a colloidal quantum dot ink that is capped using halide-based ligands alone. By judicious choice of solvents and ligands, we developed a CQD ink from which a homogeneous and thick colloidal quantum dot solid is applied in a single step. The resultant films display an n-type character, making it suitable as a key component in a solar-converting device. We demonstrate two types of quantum junction devices that exploit these iodide-ligand-based inks. We achieve solar power conversion efficiencies of 6% using this class of colloids.

  11. Energy saving using solar filters with iron base in windows; Ahorro de energia usando filtros solares con base en hierro en ventanas

    Energy Technology Data Exchange (ETDEWEB)

    Chavez Galan, Jesus

    2003-07-01

    For the high temperature seasons, the radiation emitted by the sun later introduced through the windows, provokes a great thermal gain in the buildings causing within them an excessive warming. For the cold seasons, the exterior is at low temperature and the window is the main element through which the building losses the heat generated in the interior. The former turns out into an elevated energy consumption (mainly electricity) to obtain the conditions of human thermal comfort; this altogether with the growing energy demand that the residential, commercial and public sector experiences in Mexico, constitutes a serious problem. As a proposal for the solution to the problem of thermal discomfort generated in the interior of the buildings because of the inadequate properties of the construction materials, in this work were developed solar filers with iron base by means of which it is obtained a selective control of the solar radiation that is transmitted through the windows. These solar filters consist in thin films of FeO deposited over subtracts of lime-soda glass (the most used in our country for buildings) of 600 x 300 x 3 mm, by means of the sputtering technique added with a radio frequency and flat magnetrons, starting from a pure iron target of 127 x 254 mm and using an argon plasma. To obtain the desired oxidation degree in the iron, small samples (45 x 22 mm) were subjected to a heating process in a reducing atmosphere constituted by 50% H{sub 2} + 50% N{sub 2} for a period of time of 10 minutes at a temperature of 400 centigrade. The solar filters with the FeO base present a transmissibility of 30.2 % for the visible interval of the electromagnetic spectrum (radiation with a wave length of 380-780 nm) and of 39.9 % for the near infrared (radiation with a wave length of 780-2500 nm); while the reflectivity is of 17.5 and 19% for the visible intervals and near infrared of electromagnetic spectrum respectively. A simulation was performed by means of the

  12. 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.

  13. Fuzzy rule-based model for optimum orientation of solar panels using satellite image processing

    Science.gov (United States)

    Zaher, A.; N'goran, Y.; Thiery, F.; Grieu, S.; Traoré, A.

    2017-01-01

    In solar energy converting systems, a particular attention is paid to the orientation of solar collectors in order to optimize the overall system efficiency. In this context, the collectors can be fixed or oriented by a continuous solar tracking system. The proposed approach is based on METEOSAT images processing in order to detect the cloud coverage and its duration. These two parameters are treated by a fuzzy inference system deciding the optimal position of the solar panel. In fact, three weather cases can be considered: clear, partly covered or overcast sky. In the first case, the direct sunlight is more important than the diffuse radiation, thus the panel is always pointed towards the sun. In the overcast case, the solar beam is close to zero and the panel is placed horizontally to receive the diffuse radiation. Under partly covered conditions, the fuzzy inference system decides which of the previous positions is more efficient. The proposed approach is implemented using experimental prototype located in Perpignan (France). On a period of 17 months, the results are very satisfactory, with power gains of up to 23 % compared to the collectors oriented by a continuous solar tracking.

  14. Midtemperature solar systems test facility predictions for thermal performance based on test data: Solar kinetics T-600 solar collector with FEK 244 reflector surface

    Science.gov (United States)

    Harrison, T. D.

    1981-04-01

    A program to predict the performance and measure the characteristics of commercially available solar collectors with potential for use in industrial process heat and enhanced oil recovery applications is discussed. The thermal performance predictions for the Solar Kinetics T-600 solar line focusing parabolic trough collector are presented for three output temperatures at five cities in the US.

  15. Solar Hydrogen Production via a Samarium Oxide-Based Thermochemical Water Splitting Cycle

    Directory of Open Access Journals (Sweden)

    Rahul Bhosale

    2016-04-01

    Full Text Available The computational thermodynamic analysis of a samarium oxide-based two-step solar thermochemical water splitting cycle is reported. The analysis is performed using HSC chemistry software and databases. The first (solar-based step drives the thermal reduction of Sm2O3 into Sm and O2. The second (non-solar step corresponds to the production of H2 via a water splitting reaction and the oxidation of Sm to Sm2O3. The equilibrium thermodynamic compositions related to the thermal reduction and water splitting steps are determined. The effect of oxygen partial pressure in the inert flushing gas on the thermal reduction temperature (TH is examined. An analysis based on the second law of thermodynamics is performed to determine the cycle efficiency (ηcycle and solar-to-fuel energy conversion efficiency (ηsolar−to−fuel attainable with and without heat recuperation. The results indicate that ηcycle and ηsolar−to−fuel both increase with decreasing TH, due to the reduction in oxygen partial pressure in the inert flushing gas. Furthermore, the recuperation of heat for the operation of the cycle significantly improves the solar reactor efficiency. For instance, in the case where TH = 2280 K, ηcycle = 24.4% and ηsolar−to−fuel = 29.5% (without heat recuperation, while ηcycle = 31.3% and ηsolar−to−fuel = 37.8% (with 40% heat recuperation.

  16. Solar Energy Block-Based Residential Construction for Rural Areas in the West of China

    Directory of Open Access Journals (Sweden)

    Jizhong Shao

    2016-04-01

    Full Text Available Based on the Great Western Development Strategy and the requirement for sustainable development in the west of China, rural affordable housing, energy conservation, and environmental protection are becoming development standards in the construction field. This paper mainly explores an innovative, sustainable, residential construction method for rural areas in western China, particularly the integration of solar energy technology with modern prefabricated building techniques, formally named solar energy block-based construction. The conscious approach of using volumetric blocks provides superior adaptability and expansibility in integration with a steel structure, thereby reducing the construction time and cost. Allowing a wide variety of configurations and styles in the building layout, this approach can be customized to the end-user’s precise location and climate, making rural residential buildings much more flexible and modern. To take advantage of adequate solar energy resource in western China, the blocks are associated with active and passive solar energy technologies, thereby reducing pollution, mitigating global warming, and enhancing sustainability. Therefore, we concluded that solar energy block-based construction could bring significant benefits to the environment, economy, and society. It could also promote sustainable development in the rural regions of western China.

  17. Barrier potential design criteria in multiple-quantum-well-based solar-cell structures

    Science.gov (United States)

    Mohaidat, Jihad M.; Shum, Kai; Wang, W. B.; Alfano, R. R.

    1994-01-01

    The barrier potential design criteria in multiple-quantum-well (MQW)-based solar-cell structures is reported for the purpose of achieving maximum efficiency. The time-dependent short-circuit current density at the collector side of various MQW solar-cell structures under resonant condition was numerically calculated using the time-dependent Schroedinger equation. The energy efficiency of solar cells based on the InAs/Ga(y)In(1-y)As and GaAs/Al(x)Ga(1-x)As MQW structues were compared when carriers are excited at a particular solar-energy band. Using InAs/Ga(y)In(1-y)As MQW structures it is found that a maximum energy efficiency can be achieved if the structure is designed with barrier potential of about 450 meV. The efficiency is found to decline linearly as the barrier potential increases for GaAs/Al(x)Ga(1-x)As MQW-structure-based solar cells.

  18. PV-solar / wind hybrid energy system for GSM/CDMA type mobile telephony base station

    OpenAIRE

    Pragya Nema, R.K. Nema, Saroj Rangnekar

    2010-01-01

    This paper gives the design idea of optimized PV-Solar and Wind Hybrid Energy System for GSM/CDMA type mobile base station over conventional diesel generator for a particular site in central India (Bhopal) . For this hybrid system ,the meteorological data of Solar Insolation, hourly wind speed, are taken for Bhopal-Central India (Longitude 77o.23'and Latitude 23o.21' ) and the pattern of load consumption of mobile base station are studied and suitably modeled for optimization of the hybrid en...

  19. PV-solar / Wind Hybrid Energy System for GSM/CDMA Type Mobile Telephony Base

    OpenAIRE

    Station Md. Ibrahim; Mohammad Tayyab

    2015-01-01

    This paper presents the design of optimized PV-Solar and Wind Hybrid Energy System for GSM/CDMA type mobile base station over conventional diesel generator for a particular site in south India (Chennai). For this hybrid system ,the meteorological data of Solar Insolation, hourly wind speed, are taken for Chennai (Longitude 80ο .16’and Latitude 13ο .5’ ) and the pattern of load consumption of mobile base station are studied and suitably modeled for optimization of the hybrid ...

  20. A Comparison between Physics-based and Polytropic MHD Models for Stellar Coronae and Stellar Winds of Solar Analogs

    Science.gov (United States)

    Cohen, O.

    2017-02-01

    The development of the Zeeman–Doppler Imaging (ZDI) technique has provided synoptic observations of surface magnetic fields of low-mass stars. This led the stellar astrophysics community to adopt modeling techniques that have been used in solar physics using solar magnetograms. However, many of these techniques have been neglected by the solar community due to their failure to reproduce solar observations. Nevertheless, some of these techniques are still used to simulate the coronae and winds of solar analogs. Here we present a comparative study between two MHD models for the solar corona and solar wind. The first type of model is a polytropic wind model, and the second is the physics-based AWSOM model. We show that while the AWSOM model consistently reproduces many solar observations, the polytropic model fails to reproduce many of them, and in the cases where it does, its solutions are unphysical. Our recommendation is that polytropic models, which are used to estimate mass-loss rates and other parameters of solar analogs, must first be calibrated with solar observations. Alternatively, these models can be calibrated with models that capture more detailed physics of the solar corona (such as the AWSOM model) and that can reproduce solar observations in a consistent manner. Without such a calibration, the results of the polytropic models cannot be validated, but they can be wrongly used by others.

  1. Temperature based daily incoming solar radiation modeling based on gene expression programming, neuro-fuzzy and neural network computing techniques.

    Science.gov (United States)

    Landeras, G.; López, J. J.; Kisi, O.; Shiri, J.

    2012-04-01

    The correct observation/estimation of surface incoming solar radiation (RS) is very important for many agricultural, meteorological and hydrological related applications. While most weather stations are provided with sensors for air temperature detection, the presence of sensors necessary for the detection of solar radiation is not so habitual and the data quality provided by them is sometimes poor. In these cases it is necessary to estimate this variable. Temperature based modeling procedures are reported in this study for estimating daily incoming solar radiation by using Gene Expression Programming (GEP) for the first time, and other artificial intelligence models such as Artificial Neural Networks (ANNs), and Adaptive Neuro-Fuzzy Inference System (ANFIS). Traditional temperature based solar radiation equations were also included in this study and compared with artificial intelligence based approaches. Root mean square error (RMSE), mean absolute error (MAE) RMSE-based skill score (SSRMSE), MAE-based skill score (SSMAE) and r2 criterion of Nash and Sutcliffe criteria were used to assess the models' performances. An ANN (a four-input multilayer perceptron with ten neurons in the hidden layer) presented the best performance among the studied models (2.93 MJ m-2 d-1 of RMSE). A four-input ANFIS model revealed as an interesting alternative to ANNs (3.14 MJ m-2 d-1 of RMSE). Very limited number of studies has been done on estimation of solar radiation based on ANFIS, and the present one demonstrated the ability of ANFIS to model solar radiation based on temperatures and extraterrestrial radiation. By the way this study demonstrated, for the first time, the ability of GEP models to model solar radiation based on daily atmospheric variables. Despite the accuracy of GEP models was slightly lower than the ANFIS and ANN models the genetic programming models (i.e., GEP) are superior to other artificial intelligence models in giving a simple explicit equation for the

  2. Locating the electrical junctions in Cu(In,Ga)Se 2 and Cu 2 ZnSnSe 4 solar cells by scanning capacitance spectroscopy: Locating the electrical junctions in Cu(In,Ga)Se 2 and Cu 2 ZnSnSe 4 solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Chuanxiao [National Renewable Energy Laboratory, Golden CO 80401 USA; Colorado School of Mines, Golden CO 80401 USA; Jiang, Chun-Sheng [National Renewable Energy Laboratory, Golden CO 80401 USA; Moutinho, Helio [National Renewable Energy Laboratory, Golden CO 80401 USA; Levi, Dean [National Renewable Energy Laboratory, Golden CO 80401 USA; Yan, Yanfa [The University of Toledo, Toledo OH 43606 USA; Gorman, Brian [Colorado School of Mines, Golden CO 80401 USA; Al-Jassim, Mowafak [National Renewable Energy Laboratory, Golden CO 80401 USA

    2016-08-09

    We determined the electrical junction (EJ) locations in Cu(In,Ga)Se2 (CIGS) and Cu2ZnSnSe4 (CZTS) solar cells with ~20-nm accuracy by developing scanning capacitance spectroscopy (SCS) applicable to the thin-film devices. Cross-sectional sample preparation for the SCS measurement was developed by high-energy ion milling at room temperature for polishing the cross section to make it flat, followed by low-energy ion milling at liquid nitrogen temperature for removing the damaged layer and subsequent annealing for growing a native oxide layer. The SCS shows distinct p-type, transitional, and n-type spectra across the devices, and the spectral features change rapidly with location in the depletion region, which results in determining the EJ with ~20-nm resolution. We found an n-type CIGS in the region next to the CIGS/CdS interface; thus, the cell is a homojunction. The EJ is ~40 nm from the interface on the CIGS side. In contrast, such an n-type CZTS was not found in the CZTS/CdS cells. The EJ is ~20 nm from the CZTS/CdS interface, which is consistent with asymmetrical carrier concentrations of the p-CZTS and n-CdS in a heterojunction cell. Our results of unambiguously determination of the junction locations contribute significantly to understanding the large open-circuit voltage difference between CIGS and CZTS.

  3. Ionospheric and magnetospheric effects of solar flares monitored by ground-based riometer and magnetometers

    Science.gov (United States)

    Ronan Coelho Stekel, Tardelli; Schuch, Nelson Jorge; Echer, Ezequiel; Guarnieri, Fernando; Makita, Kazuo; Espindola Antunes, Cassio; Moro, Juliano; Machado Paulo, Claudio

    The solar flare incidence follows a behavior similar to the solar cycle activity, which results in periodic disturbances on the Earth's ionosphere and magnetosphere. The correlation of this phenomenon can provide important information about the magnetosphere, the Sun/Earth interaction, as well as events occurring in the ionosphere which can, for instance, generate disturbances in telecommunications, small satellites or even in the space weather. Riometer and magnetometers data analysis can provide useful way for measuring and understanding the effects of solar flare radiation in the ionosphere and magnetosphere. The Solar Flare effect (SFE) is associated with the sudden change of ionospheric currents caused by the extra ionization produced by soft X-ray (0.1 to 9.0 nm) and EUV (9.0 to 100.0 nm) radiation from the solar flare. The objective of this work is to present the correlation of the ionospheric and magnetospheric (H, D, Z) sudden disturbances due to high-intensity solar flares (M and X class), that can emit up to 1032 ergs of energy. For this purpose, analysis were performed for the riometer and magnetometers dedicated to study the Solar-Earth interactions at the Southern Space Observatory (SSO/CRS/INPE -MCT), (29.4° S, 53.8° W, 480m a.s.l), São Martinho da a Serra, RS, Brazil. To identify and investigate the sudden radiation increase caused by the solar flare, the X-ray data (0.1 to 0.8 nm) from GOES Satellites and the EUV data (26.0 to 34.0 nm and 0.1 to 50.0 nm) from the Solar EUV Monitor (SEM) on the SOHO spacecraft are correlated. With the analysis of these ground-based instruments and spacecrafts data, the correlation of the solar activity and the magnetospheric and ionospheric disturbances were performed, as for the Sudden Ionospheric Disturbance (SID) and Magnetic Crochet about 60% D-component variation during a large solar flare was observed.

  4. Synchrotron-based spectroscopy for solar energy conversion

    Science.gov (United States)

    Himpsel, F. J.; Cook, P. L.; Zegkinoglou, I.; Boukahil, Idris; Qiao, R.; Yang, W.; Pemmaraju, S. C.; Prendergast, D.; Kronawitter, C. X.; Kibria, M. G.; Mi, Zetian; Vayssieres, L.

    2015-09-01

    X-rays from synchrotron radiation enable incisive spectroscopic techniques which speed up the discovery of new materials for photovoltaics and photoelectrochemistry. A particularly useful method is X-ray absorption spectroscopy (XAS), which probes empty electronic states. XAS is element- and bond-specific, with the additional capability of determining the bond orientation. Close feedback from density functional calculations makes it possible to discover and exploit systematic trends in the electronic properties. Case studies are presented, such as solar cells that combine an absorber with an electron donor and an acceptor in one molecular complex and nanowire arrays serving as photoanodes for water splitting. In addition to the energy levels the lifetimes of the charge carriers play an essential role in device performance. A new generation of laser-like X-ray sources will make it possible to follow the fate of excited charge carriers traveling across a molecular complex or through a device structure in real time.

  5. Hydrogen based energy storage for solar energy systems

    Energy Technology Data Exchange (ETDEWEB)

    Vanhanen, J.; Hagstroem, M.; Lund, P. [Helsinki Univ. of Technology, Otaniemi (Finland). Advanced Energy Systems

    1998-10-01

    The main technical constraint in solar energy systems which operate around the year is the lack of suitable long-term energy storage. Conventional solutions to overcome the problem of seasonal storage in PV power systems are to use oversized batteries as a seasonal energy storage, or to use a diesel back-up generator. However, affordable lead-acid batteries are not very suitable for seasonal energy storage because of a high self-discharge rate and enhanced deterioration and divergence of the single cells during prolonged periods of low state of charge in times of low irradiation. These disadvantages can be avoided by a back-up system, e.g. a diesel generator, which car supply energy to the loads and charge the battery to the full state of charge to avoid the above mentioned disadvantages. Unfortunately, diesel generators have several disadvantages, e.g. poor starting reliability, frequent need for maintenance and noise

  6. Thermochemical cycles based on metal oxides for solar hydrogen production; Ciclos termoquimicos basados en oxidos metalicos para produccion de hidrogeno solar

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez Saavedra, R.; Quejido Cabezas, J.

    2012-11-01

    The growing demand for energy requires the development and optimization of alternative energy sources. One of the options currently being investigated is solar hydrogen production with thermochemical cycles. This process involves the use of concentrated solar radiation as an energy source to dissociate water through a series of endothermic and exothermic chemical reactions, for the purpose of obtaining hydrogen on a sustainable basis. Of all the thermochemical cycles that have been evaluated, the most suitable ones for implementation with solar energy are those based on metal oxides. (Author) 20 refs.

  7. Calculated thermal performance of solar collectors based on measured weather data from 2001-2010

    DEFF Research Database (Denmark)

    Dragsted, Janne; Furbo, Simon; Andersen, Elsa;

    2015-01-01

    This paper presents an investigation of the differences in modeled thermal performance of solar collectors when meteorological reference years are used as input and when mulit-year weather data is used as input. The investigation has shown that using the Danish reference year based on the period...... with an increase in global radiation. This means that besides increasing the thermal performance with increasing the solar radiation, the utilization of the solar radiation also becomes better....... 1975-1990 will result in deviations of up to 39 % compared with thermal performance calculated with multi-year the measured weather data. For the newer local reference years based on the period 2001-2010 the maximum deviation becomes 25 %. The investigation further showed an increase in utilization...

  8. High Open-Circuit Voltage Solar Cells Based on Organic-Inorganic Lead Bromide Perovskite.

    Science.gov (United States)

    Edri, Eran; Kirmayer, Saar; Cahen, David; Hodes, Gary

    2013-03-21

    Mesoscopic solar cells, based on solution-processed organic-inorganic perovskite absorbers, are a promising avenue for converting solar to electrical energy. We used solution-processed organic-inorganic lead halide perovskite absorbers, in conjunction with organic hole conductors, to form high voltage solar cells. There is a dire need for low-cost cells of this type, to drive electrochemical reactions or as the high photon energy cell in a system with spectral splitting. These perovskite materials, although spin-coated from solution, form highly crystalline materials. Their simple synthesis, along with high chemical versatility, allows tuning their electronic and optical properties. By judicious selection of the perovskite lead halide-based absorber, matching organic hole conductor, and contacts, a cell with a ∼ 1.3 V open circuit voltage was made. While further study is needed, this achievement provides a general guideline for additional improvement of cell performance.

  9. Web-Based Application for the Sizing of a Photovolatic (PV Solar Power System

    Directory of Open Access Journals (Sweden)

    F.K. Ariyo

    2016-07-01

    Full Text Available The harnessing of solar energy, especially for provision of energy for residential consumption, has been on the rise in developing countries, especially Nigeria, in recent times. Due to this reason, there is the need for a tool which makes the design of the system needed to harness this abundant energy more accurate and efficient by considering several factors including specific climate conditions of the country. This paper presents the design and development of a web-based application that helps to estimate the ratings and quantities of the components of the Solar Photovoltaic (PV System (which converts the solar energy to electrical energy required based on several factors including the specific climatic conditions of major cities in Nigeria.

  10. Soft X-rays shedding light on thin-film solar cell surfaces and interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Bär, M., E-mail: marcus.baer@helmholtz-berlin.de [Solar Energy Research, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH (HZB), D-14109 Berlin (Germany); Institut für Physik und Chemie, Brandenburgische Technische Universität Cottbus, D-03046 Cottbus (Germany); Department of Chemistry, University of Nevada, Las Vegas (UNLV), Las Vegas, NV 89154 (United States); Pookpanratana, S. [Department of Chemistry, University of Nevada, Las Vegas (UNLV), Las Vegas, NV 89154 (United States); Weinhardt, L. [Department of Chemistry, University of Nevada, Las Vegas (UNLV), Las Vegas, NV 89154 (United States); Institute for Photon Science and Synchrotron Radiation, Karlsruhe Institute of Technology (KIT), D-76344 Eggenstein-Leopoldshafen (Germany); ANKA Synchrotron Radiation Facility, Karlsruhe Institute of Technology, D-76344 Eggenstein-Leopoldshafen (Germany); Wilks, R.G.; Schubert, B.A.; Marsen, B.; Unold, T. [Solar Energy Research, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH (HZB), D-14109 Berlin (Germany); Blum, M.; Krause, S. [Department of Chemistry, University of Nevada, Las Vegas (UNLV), Las Vegas, NV 89154 (United States); Zhang, Y. [Department of Chemistry, University of Nevada, Las Vegas (UNLV), Las Vegas, NV 89154 (United States); Department of Physics, Xiamen University, Xiamen, Fujian 361005 (China); Ranasinghe, A. [Department of Chemistry, University of Nevada, Las Vegas (UNLV), Las Vegas, NV 89154 (United States); Ramanathan, K.; Repins, I.; Contreras, M.A. [National Renewable Energy Laboratory (NREL), Golden, CO 80401 (United States); Nishiwaki, S. [Institute for Energy Conversion (IEC), University of Delaware, Newark, DE 19716 (United States); and others

    2013-10-15

    Highlights: ► S/Se gradient-driven chemical interaction at the CdS/CIG(S)Se interface. ► Depth-dependent band gap in chalcopyrites. ► Band alignment at the CdS/Cu{sub 2}ZnSnS{sub 4} solar cell heterojunction. ► Post-deposition treatment induces intermixing in the CdTe/CdS solar cell structure. -- Abstract: Thin-film solar cells based on compound semiconductors consist of a multilayer structure with various interfaces and contain a multitude of elements and impurities, etc. A rapid progress of these photovoltaic technologies can only be achieved by an insight-driven optimization/development. Hence it is crucial to characterize and understand the relationship between the chemical and electronic properties of these components. This paper reviews some examples of our recent work characterizing compound semiconductor thin films using laboratory- and synchrotron-based electron and soft X-ray spectroscopic characterization methods. It is demonstrated how these different analytical techniques are extraordinarily powerful to reveal the material characteristics from many different perspectives, ultimately resulting in a comprehensive picture of the related electronic and chemical properties. As examples, the paper will discuss the electronic surface structure of chalcopyrite thin-film solar cell absorbers, the chemical structure of the CdS/chalcopyrite interface, present the band alignment at the CdS/kesterite interface, and report on how post-deposition treatments cause chemical interaction/interdiffusion processes in CdTe/CdS thin-film solar cell structures.

  11. Energy and exergy performance investigation of transcritical CO2-based Rankine cycle powered by solar energy

    Institute of Scientific and Technical Information of China (English)

    ZHANG XinRong; LI XiaoJuan

    2012-01-01

    A comprehensive performance evaluation of a solar assisted transcritical CO2-based Rankine cycle system is made with exergy analysis method.The actual thermal data taken from the all-day experiment of the system are utilized to determine energy transfer and the exergy destructions in each component of the system.In addition,a hypothetical carbon dioxide expansion turbine is introduced,then two thermodynamic models for solar transcritical carbon dioxide Rankine cycles with a throttling valve (experiment) and with an expansion turbine have been established with exergy analysis method.The obtained results clearly show that solar collector contributes the largest share to system irreversibility and entropy generation in the all-day working state,and the exergy improvement potential of solar collector is the maximum in the working state.So this component should be the optimization design focus to improve system exergy effectiveness.For the cycle with the turbine,the energy efficiency and the entropy generation are not much higher than the cycle with throttling valve,but the exergy efficiency of the cycle with turbine is twice of the cycle with throttling valve.It provides more guidance when the transcritical CO2-based Rankine system is in a large-scale solar application.

  12. Combinatorial sputtering of Ga-doped (Zn,Mg)O for contact applications in solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Rajbhandari, Pravakar P.; Bikowski, André; 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.

  13. 78 FR 49507 - Genesis Solar, LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes Request...

    Science.gov (United States)

    2013-08-14

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Genesis Solar, LLC; Supplemental Notice That Initial Market- Based Rate...-referenced proceeding of Genesis Solar, LLC's application for market-based rate authority, with...

  14. 78 FR 34371 - Centinela Solar Energy, LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes...

    Science.gov (United States)

    2013-06-07

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Centinela Solar Energy, LLC; Supplemental Notice That Initial Market-Based... above-referenced proceeding, of Centinela Solar Energy, LLC's application for market-based...

  15. Primera cita de reproducción de cigüeñuela común Himantopus himantopus L., 1758 en Urdaibai (Bizkaia

    Directory of Open Access Journals (Sweden)

    ARIZAGA, J., AZKONA, A., CEPEDA, X., MAGUREGI, J., UNAMUNO, E., UNAMUNO, J.M.

    2012-01-01

    Full Text Available La colonización del Cantábrico por la cigüeñuela común Himantopus himantopus L., 1758 es un fenómeno reciente (se cita por primera vez en 2009 en Asturias y Cantabria. En 2012, y por primera vez para Urdaibai y la costa vasca, se constata la reproducción de cigüeñuela en la laguna de Orueta, en el municipio de Gautegiz-Arteaga (Bizkaia. En particular, una pareja fue capaz de sacar adelante 3 pollos.

  16. Design of Three Phase Solar-Based 4.5kw Ac Power Inverter Station

    Directory of Open Access Journals (Sweden)

    Dr.J.C. Onuegbu

    2013-07-01

    Full Text Available The design model of a 4.50Kilowatt, 3-phase, 50 hertz solar-based power generating station was examined by the paper. The power station is a dual source input generating station using 8 series connected 100A, 12V batteries per phase as backup, the solar panels being the main frame. An inverter of 12Volt direct current input voltage was incorporated to supply an output of 3-phase, 220Volts and 50 hertz alternating current. A charging circuit was installed to monitor charging level and to preserve the accumulator’s life span. The paper also looked into the solar-based power station component design model. The batteries therein are back-up and the system will ensure 24-hours reliable power supply. The setup has a normally closed switching relay ready to pickup the auxiliary battery supply within a few milliseconds after the solar source voltage drops below a stipulated level. The three phase a.c. voltage was achieved using standby on-line circuit with cascaded 741-based flip-flop at the base of the transistor drivers of the 3-phase power transformer. This model circuit reduced the load on each phase winding and facilitated reliable and uninterruptible power supply. The delta-wyeconnected transformer will guarantee proper phase shift of 120 degrees that will emulate alternating current voltage similar to the conventional generator voltage.

  17. Tin- and Lead-Based Perovskite Solar Cells under Scrutiny: An Environmental Perspective

    DEFF Research Database (Denmark)

    Serrano-Luján, Lucía; Espinosa Martinez, Nieves; Larsen-Olsen, Thue Trofod

    2015-01-01

    The effect of substituting lead with tin in perovskite-based solar cells (PSCs) has shows that lead is preferred over tin by a lower cumulative energy demand. The results, which also include end-of-life management, show that a recycling scenario that carefully handles emission of lead enables use...

  18. Enhancing the Efficiency of Silicon-Based Solar Cells by the Piezo-Phototronic Effect.

    Science.gov (United States)

    Zhu, Laipan; Wang, Longfei; Pan, Caofeng; Chen, Libo; Xue, Fei; Chen, Baodong; Yang, Leijing; Su, Li; Wang, Zhong Lin

    2017-02-28

    Although there are numerous approaches for fabricating solar cells, the silicon-based photovoltaics are still the most widely used in industry and around the world. A small increase in the efficiency of silicon-based solar cells has a huge economic impact and practical importance. We fabricate a silicon-based nanoheterostructure (p(+)-Si/p-Si/n(+)-Si (and n-Si)/n-ZnO nanowire (NW) array) photovoltaic device and demonstrate the enhanced device performance through significantly enhanced light absorption by NW array and effective charge carrier separation by the piezo-phototronic effect. The strain-induced piezoelectric polarization charges created at n-doped Si-ZnO interfaces can effectively modulate the corresponding band structure and electron gas trapped in the n(+)-Si/n-ZnO NW nanoheterostructure and thus enhance the transport process of local charge carriers. The efficiency of the solar cell was improved from 8.97% to 9.51% by simply applying a static compress strain. This study indicates that the piezo-phototronic effect can enhance the performance of a large-scale silicon-based solar cell, with great potential for industrial applications.

  19. Asteroseismology of solar-type stars with Kepler: III. Ground-based data

    DEFF Research Database (Denmark)

    Karoff, Christoffer; Molenda-Żakowicz , J.

    2010-01-01

    We report on the ground-based follow-up program of spectroscopic and photometric observations of solar-like asteroseismic targets for the Kepler space mission. These stars constitute a large group of more than a thousand objects which are the subject of an intensive study by the Kepler Asteroseis...

  20. Experimental and Computer Modelling Studies of Metastability of Amorphous Silicon Based Solar Cells

    NARCIS (Netherlands)

    Munyeme, Geoffrey

    2003-01-01

    We present a combination of experimental and computer modelling studies of the light induced degradation in the performance of amorphous silicon based single junction solar cells. Of particular interest in this study is the degradation kinetics of different types of amorphous silicon single junction

  1. Transport, Interfaces, and Modeling in Amorphous Silicon Based Solar Cells: Final Technical Report, 11 February 2002 - 30 September 2006

    Energy Technology Data Exchange (ETDEWEB)

    Schiff, E. A.

    2008-10-01

    Results for a-Si characteristics/modeling; photocarrier drift mobilities in a-Si;H, ..mu..c-Si:H, CIGS; hole-conducting polymers as p-layer for a-Si and c-Si; IR spectra of p/i and n/i interfaces in a-Si.

  2. Solar cells based on InP/GaP/Si structure

    Science.gov (United States)

    Kvitsiani, O.; Laperashvil, D.; Laperashvili, T.; Mikelashvili, V.

    2016-10-01

    Solar cells (SCs) based on III-V semiconductors are reviewed. Presented work emphases on the Solar Cells containing Quantum Dots (QDs) for next-generation photovoltaics. In this work the method of fabrication of InP QDs on III-V semiconductors is investigated. The original method of electrochemical deposition of metals: indium (In), gallium (Ga) and of alloys (InGa) on the surface of gallium phosphide (GaP), and mechanism of formation of InP QDs on GaP surface is presented. The possibilities of application of InP/GaP/Si structure as SC are discussed, and the challenges arising is also considered.

  3. Plasma monitoring and PECVD process control in thin film silicon-based solar cell manufacturing

    Directory of Open Access Journals (Sweden)

    Gabriel Onno

    2014-02-01

    Full Text Available A key process in thin film silicon-based solar cell manufacturing is plasma enhanced chemical vapor deposition (PECVD of the active layers. The deposition process can be monitored in situ by plasma diagnostics. Three types of complementary diagnostics, namely optical emission spectroscopy, mass spectrometry and non-linear extended electron dynamics are applied to an industrial-type PECVD reactor. We investigated the influence of substrate and chamber wall temperature and chamber history on the PECVD process. The impact of chamber wall conditioning on the solar cell performance is demonstrated.

  4. Compact solar autoclave based on steam generation using broadband light-harvesting nanoparticles.

    Science.gov (United States)

    Neumann, Oara; Feronti, Curtis; Neumann, Albert D; Dong, Anjie; Schell, Kevin; Lu, Benjamin; Kim, Eric; Quinn, Mary; Thompson, Shea; Grady, Nathaniel; Nordlander, Peter; Oden, Maria; Halas, Naomi J

    2013-07-16

    The lack of readily available sterilization processes for medicine and dentistry practices in the developing world is a major risk factor for the propagation of disease. Modern medical facilities in the developed world often use autoclave systems to sterilize medical instruments and equipment and process waste that could contain harmful contagions. Here, we show the use of broadband light-absorbing nanoparticles as solar photothermal heaters, which generate high-temperature steam for a standalone, efficient solar autoclave useful for sanitation of instruments or materials in resource-limited, remote locations. Sterilization was verified using a standard Geobacillus stearothermophilus-based biological indicator.

  5. Sulfur Based Thermochemical Heat Storage for Baseload Concentrated Solar Power Generation

    Energy Technology Data Exchange (ETDEWEB)

    wong, bunsen

    2014-11-20

    This project investigates the engineering and economic feasibility of supplying baseload power using a concentrating solar power (CSP) plant integrated with sulfur based thermochemical heat storage. The technology stores high temperature solar heat in the chemical bonds of elemental sulfur. Energy is recovered as high temperature heat upon sulfur combustion. Extensive developmental and design work associated with sulfur dioxide (SO2) disproportionation and sulfuric acid (H2SO4) decomposition chemical reactions used in this technology had been carried out in the two completed phases of this project. The feasibility and economics of the proposed concept was demonstrated and determined.

  6. Simulation of solid-state dye solar cells based on organic and Perovskite sensitizers

    Science.gov (United States)

    Di Carlo, Aldo; Gentilini, Desireé; Gagliardi, Alessio

    2015-03-01

    In this work we present a multiscale numerical simulation of solid-state Dye and Perovskite Solar Cells where the real morphology of the mesoporous active layer is taken into account. Band alignment and current densities are computed using the drift-diffusion model. In the case of Dye cells, a portion of the real interface is merged between two regions described using the effective medium approximation, casting light on the role of trapped states at the interface between TiO2 / Dye / hole transporting materials. A second case of study is the simulation of Perovskite Solar Cell where the performances of cells based on Alumina and Titania mesoporous layer are compared.

  7. Sulfur Based Thermochemical Heat Storage for Baseload Concentrated Solar Power Generation

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Bunsen [General Atomics, San Diego, CA (United States)

    2014-11-01

    This project investigates the engineering and economic feasibility of supplying baseload power using a concentrating solar power (CSP) plant integrated with sulfur based thermochemical heat storage. The technology stores high temperature solar heat in the chemical bonds of elemental sulfur. Energy is recovered as high temperature heat upon sulfur combustion. Extensive developmental and design work associated with sulfur dioxide (SO2) disproportionation and sulfuric acid (H2SO4) decomposition chemical reactions used in this technology had been carried out in the two completed phases of this project. The feasibility and economics of the proposed concept was demonstrated and determined.

  8. Time dependent capacitance voltage measurements on Cu(In,Ga)Se{sub 2} solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Adler, Tobias; Klein, Andreas [Darmstadt University of Technology, Institute of Materials Science, Petersenstrasse 32, D-64287 Darmstadt (Germany); Witte, Wolfram; Hariskos, Dimitrios [Zentrum fuer Sonnenenergie- und Wasserstoff-Forschung Baden-Wuerttemberg (ZSW), Industriestrasse 6, D-70565 Stuttgart (Germany)

    2011-07-01

    Capacitance Voltage (C-V) measurements are widely used to determine the doping density of semiconductor interfaces in dependence on the width of the space charge layer. In Cu(In,Ga)Se{sub 2} (CIGS) solar cells we observe a time dependent capacitance signal, which can be explained by different models like filling and emptying of electronic (metastable) defect states or by the diffusion of copper ions. The observed capacitance transients are compared to the different models.

  9. Considerations for Solar Energy Technologies to Make Progress Towards Grid Price Parity

    Energy Technology Data Exchange (ETDEWEB)

    Woodhouse, Michael; Fu, Ran; Chung, Donald; Horowitz, Kelsey; Remo, Timothy; Feldman, David; Margolis, Robert

    2015-11-07

    In this seminar the component costs for solar photovoltaics module and system prices will be highlighted. As a basis for comparison to other renewable and traditional energy options, the metric of focus will be total lifecycle cost-of-energy (LCOE). Several innovations to traditional photovoltaics technologies (including crystalline silicon, CdTe, and CIGS) and developing technologies (including organics and perovskites) that may close the gaps in LCOE will be discussed.

  10. Carbon-Nanohorn Based Nanofluids for a Direct Absorption Solar Collector for Civil Application.

    Science.gov (United States)

    Moradi, A; Sani, E; Simonetti, M; Francini, F; Chiavazzo, E; Asinari, P

    2015-05-01

    Direct solar absorption has been often considered in the past as a possible solution for solar thermal collectors for residential and small commercial applications. A direct absorption could indeed improve the performance of solar collectors by skipping one step of the heat transfer mechanism in standard devices and having a more convenient temperature distribution inside the collector. Classical solar thermal collectors have a metal sheet as absorber, designed such that water has the minimum temperature in each transversal section, in order to collect as much solar thermal energy as possible. On the other hand, in a direct configuration, the hottest part of the system is the operating fluid and this allows to have a more efficient conversion. Nanofluids, i.e., fluids with a suspension of nanoparticles, such as carbon nanohorns, could be a good and innovative family of absorbing fluids owing to their higher absorption coefficient compared to the base fluid and stability under moderate temperature gradients. Moreover, carbon nanohorns offer the remarkable advantage of a reduced toxicity over other carbon nanoparticles. In this work, a three-dimensional model of the absorption phenomena in nanofluids within a cylindrical tube is coupled with a computational fluid dynamics (CFD) analysis of the flow and temperature field. Measured optical properties of nanofluids at different concentrations have been implemented in the model. Heat losses due to conduction, convection and radiation at the boundaries are considered as well.

  11. 25th anniversary article: Rise to power--OPV-based solar parks.

    Science.gov (United States)

    Krebs, Frederik C; Espinosa, Nieves; Hösel, Markus; Søndergaard, Roar R; Jørgensen, Mikkel

    2014-01-08

    A solar park based on polymer solar cells is described and analyzed with respect to performance, practicality, installation speed, and energy payback time. It is found that a high voltage installation where solar cells are all printed in series enables an installation rate in Watts installed per minute that far exceed any other PV technology in existence. The energy payback time for the practical installation of polymer solar cell foil on a wooden 250 square meter platform in its present form is 277 days when operated in Denmark and 180 days when operated in southern Spain. The installation and de-installation rate is above 100 m min⁻¹, which, with the present performance and web width, implies installation of >200 W min⁻¹. In comparison, this also exceeds the overall manufacturing speed of the polymer solar cell foil with a width of 305 mm which is currently 1 m min⁻¹ for complete encapsulated and tested foil. It is also significant that simultaneous installation and de-installation which enables efficient schemes for decommissioning and recycling is possible. It is highlighted where research efforts should most rationally be invested in order to make grid electricity from OPV a reality (and it is within reach).

  12. Refraction-Assisted Solar Thermoelectric Generator based on Phase-Change Lens.

    Science.gov (United States)

    Kim, Myoung-Soo; Kim, Min-Ki; Jo, Sung-Eun; Joo, Chulmin; Kim, Yong-Jun

    2016-01-01

    Solar thermoelectric generators (STEGs), which are used for various applications, (particularly small size electronic devices), have optical concentration systems for high energy conversion efficiency. In this study, a refraction-assisted STEG (R-STEG) is designed based on phase-change materials. As the phase-change material (PCM) changes phase from solid to liquid, its refractive index and transmittance also change, resulting in changes in the refraction of the sunlight transmitted through it, and concentration of solar energy in the phase-change lens. This innovative design facilitates double focusing the solar energy through the optical lens and a phase-change lens. This mechanism resulted in the peak energy conversion efficiencies of the R-STEG being 60% and 86% higher than those of the typical STEG at solar intensities of 1 kW m(-2) and 1.5 kW m(-2), respectively. In addition, the energy stored in PCM can help to generate steady electrical energy when the solar energy was removed. This work presents significant progress regarding the optical characteristic of PCM and optical concentration systems of STEGs.

  13. Refraction-Assisted Solar Thermoelectric Generator based on Phase-Change Lens

    Science.gov (United States)

    Kim, Myoung-Soo; Kim, Min-Ki; Jo, Sung-Eun; Joo, Chulmin; Kim, Yong-Jun

    2016-06-01

    Solar thermoelectric generators (STEGs), which are used for various applications, (particularly small size electronic devices), have optical concentration systems for high energy conversion efficiency. In this study, a refraction-assisted STEG (R-STEG) is designed based on phase-change materials. As the phase-change material (PCM) changes phase from solid to liquid, its refractive index and transmittance also change, resulting in changes in the refraction of the sunlight transmitted through it, and concentration of solar energy in the phase-change lens. This innovative design facilitates double focusing the solar energy through the optical lens and a phase-change lens. This mechanism resulted in the peak energy conversion efficiencies of the R-STEG being 60% and 86% higher than those of the typical STEG at solar intensities of 1 kW m‑2 and 1.5 kW m‑2, respectively. In addition, the energy stored in PCM can help to generate steady electrical energy when the solar energy was removed. This work presents significant progress regarding the optical characteristic of PCM and optical concentration systems of STEGs.

  14. Recent progress in ZnO-based nanostructured ceramics in solar cell applications.

    Science.gov (United States)

    Loh, Leonard; Dunn, Steve

    2012-11-01

    ZnO is widely used as an n-type semiconductor in various solar cell structures; including dye-sensitized, organic, hybrid and solid-state solar cells. Here, we review advances in ZnO-based solar cell applications, looking at the influence of morphology, as well as the effect of different materials and sensitizers. ZnO morphologies play an important role in changing the surface area and charge transport properties, affecting the performance of the solar cells. External quantum efficiencies using purely ZnO as the active material has generally been below 3% with some dye-sensitized solar cells using liquid electrolytes above 5%. Sensitizers such as organic and inorganic dyes, quantum dots and hole conductors have been shown to influence cell efficiency by improving the absorption or providing improved charge transport. The combination of ZnO with other nanomaterials such as, TiO2, SiO2 and ZrO2 in core-shell structures or buffer layers creates improved electron transport by controlling recombination at interfaces and increasing stability of the device. The highest reported efficiencies to date were from combinational structures at 7.07% for ZnO nanosheets with TiO2 nanoparticulate coating and 7% for ZnO core-TiO2 shell structures.

  15. Balancing autonomy and utilization of solar power and battery storage for demand based microgrids

    Science.gov (United States)

    Lawder, Matthew T.; Viswanathan, Vilayanur; Subramanian, Venkat R.

    2015-04-01

    The growth of intermittent solar power has developed a need for energy storage systems in order to decouple generation and supply of energy. Microgrid (MG) systems comprising of solar arrays with battery energy storage studied in this paper desire high levels of autonomy, seeking to meet desired demand at all times. Large energy storage capacity is required for high levels of autonomy, but much of this expensive capacity goes unused for a majority of the year due to seasonal fluctuations of solar generation. In this paper, a model-based study of MGs comprised of solar generation and battery storage shows the relationship between system autonomy and battery utilization applied to multiple demand cases using a single particle battery model (SPM). The SPM allows for more accurate state-of-charge and utilization estimation of the battery than previous studies of renewably powered systems that have used empirical models. The increased accuracy of battery state estimation produces a better assessment of system performance. Battery utilization will depend on the amount of variation in solar insolation as well as the type of demand required by the MG. Consumers must balance autonomy and desired battery utilization of a system within the needs of their grid.

  16. Balancing Autonomy and Utilization of Solar Power and Battery Storage for Demand Based Microgrids.

    Energy Technology Data Exchange (ETDEWEB)

    Lawder, Matthew T.; Viswanathan, Vilayanur V.; Subramanian, Venkat R.

    2015-04-01

    The growth of intermittent solar power has developed a need for energy storage systems in order to decouple generation and supply of energy. Microgrid (MG) systems comprising of solar arrays with battery energy storage studied in this paper desire high levels of autonomy, seeking to meet desired demand at all times. Large energy storage capacity is required for high levels of autonomy, but much of this expensive capacity goes unused for a majority of the year due to seasonal fluctuations of solar generation. In this paper, a model-based study of MGs comprised of solar generation and battery storage shows the relationship between system autonomy and battery utilization applied to multiple demand cases using a single particle battery model (SPM). The SPM allows for more accurate state-of-charge and utilization estimation of the battery than previous studies of renewably powered systems that have used empirical models. The increased accuracy of battery state estimation produces a better assessment of system performance. Battery utilization will depend on the amount of variation in solar insolation as well as the type of demand required by the MG. Consumers must balance autonomy and desired battery utilization of a system within the needs of their grid.

  17. Metamaterial-based high efficiency absorbers for high temperature solar applications (Conference Presentation)

    Science.gov (United States)

    Yellowhair, Julius E.; Kwon, Hoyeong; Alù, Andrea; Jarecki, Robert L.; Shinde, Subhash L.

    2016-09-01

    Operation of concentrated solar power receivers at higher temperatures (Existing coatings, however, tend to degrade rapidly at elevated temperatures. In this paper, we report on the initial designs, fabrication, and characterization of spectrally selective metamaterial-based absorbers for high-temperature, high-thermal flux environments important for solarized sCO2 power cycles. Metamaterials are structured media whose optical properties are determined by sub-wavelength structural features instead of bulk material properties, providing unique solutions by decoupling the optical absorption spectrum from thermal stability requirements. The key enabling innovative concept proposed is the use of structured surfaces with spectral responses that can be tailored to optimize the absorption and retention of solar energy for a given temperature range. In this initial study we use Tungsten for its stability in expected harsh environments, compatibility with microfabrication techniques, and required optical performance. Our goal is to tailor the optical properties for high (near unity) absorptivity across the majority of the solar spectrum and over a broad range of incidence angles, and at the same time achieve negligible absorptivity in the near infrared to optimize the energy absorbed and retained. To this goal, we apply the recently developed concept of plasmonic Brewster angle to suitably designed nanostructured Tungsten surfaces. We predict that this will improve the receiver thermal efficiencies by at least 10% over current solar receivers.

  18. Performance Assessment of a Solar-Assisted Desiccant-Based Air Handling Unit Considering Different Scenarios

    Directory of Open Access Journals (Sweden)

    Giovanni Angrisani

    2016-09-01

    Full Text Available In this paper, three alternative layouts (scenarios of an innovative solar-assisted hybrid desiccant-based air handling unit (AHU are investigated through dynamic simulations. Performance is evaluated with respect to a reference system and compared to those of the innovative plant without modifications. For each scenario, different collector types, surfaces and tilt angles are considered. The effect of the solar thermal energy surplus exploitation for other low-temperature uses is also investigated. The first alternative scenario consists of the recovery of the heat rejected by the condenser of the chiller to pre-heat the regeneration air. The second scenario considers the pre-heating of regeneration air with the warmer regeneration air exiting the desiccant wheel (DW. The last scenario provides pre-cooling of the process air before entering the DW. Results reveal that the plants with evacuated solar collectors (SC can ensure primary energy savings (15%–24% and avoid equivalent CO2 emissions (14%–22%, about 10 percentage points more than those with flat-plate collectors, when the solar thermal energy is used only for air conditioning and the collectors have the best tilt angle. If all of the solar thermal energy is considered, the best results with evacuated tube collectors are approximately 73% in terms of primary energy saving, 71% in terms of avoided equivalent CO2 emissions and a payback period of six years.

  19. Flux Emergence In The Solar Photosphere - Diagnostics Based On 3-D Rradiation-MHD Simulations

    Science.gov (United States)

    Yelles Chaouche, L.; Cheung, M.; Lagg, A.; Solanki, S.

    2006-08-01

    We investigate flux tube emergence in the solar photosphere using a diagnostic procedure based on analyzing Stokes signals from different spectral lines calculated in 3-D radiation-MHD simulations. The simulations include the effects of radiative transport and partial ionization and cover layers both above and below the solar surface. The simulations consider the emergence of a twisted magnetic flux tube through the solar surface. We consider different stages in the emergence process, starting from the early appearance of the flux tube at the solar surface, and following the emergence process until the emerged flux looks similar to a normal bipolar region. At every stage we compute line profiles by numerically solving the Unno-Rachkovsky equations at every horizontal grid point. Then, following observational practice, we apply Milne-Eddington-type inversions to the synthetic spectra in order to retrieve different atmospheric parameters. We include the influence of spatial smearing on the deduced atmospheric parameters to identify signatures of different stages of flux emergence in the solar photosphere.

  20. Adaptive Critic Based Neuro-Fuzzy Tracker for Improving Conversion Efficiency in PV Solar Cells

    Directory of Open Access Journals (Sweden)

    Halimeh Rashidi

    2012-08-01

    Full Text Available The output power of photovoltaic systems is directly related to the amount of solar energy collected by the system and it is therefore necessary to track the sun’s position with high accuracy. This study proposes multi-agent adaptive critic based nero fuzzy solar tracking system dedicated to PV panels. The proposed tracker ensures the optimal conversion of solar energy into electricity by properly adjusting the PV panels according to the position of the sun. To evaluate the usefulness of the proposed method, some computer simulations are performed and compared with fuzzy PD controller. Obtained results show the proposed control strategy is very robust, flexible and could be used to get the desired performance levels. The response time is also very fast. Simulation results that have been compared with fuzzy PD controller show that our method has the better control performance than fuzzy PD controller.

  1. High-efficiency dye-sensitized solar cells using ferrocene-based electrolytes and natural photosensitizers

    Science.gov (United States)

    Sönmezoğlu, Savaş; Akyürek, Cafer; Akin, Seçkin

    2012-10-01

    A new and promising dye-sensitized solar cell (DSSC) bilayer design was developed using an Fe2+/Fe3+ (ferrocene) liquid electrolyte and natural dyes extracted from Hypericum perforatum, Rubia tinctorum L. and Reseda luteola. The photovoltaic parameters controlling the device performance were then investigated. A DSSC based on quercetin dye displayed the most efficient solar to electricity conversion efficiency compared with other dyes with a maximum η value of 2.17%. Maximum overall conversion efficiencies under simulated sunlight that was comparable to natural photosynthesis were increased by 15%. The identification of appropriate additives for improving VOC without causing dye degradation may result in further enhancement of cell performance, making the practical application of such systems more suitable for achieving economically viable solar energy devices.

  2. Analysis of ionospheric irregularities during total solar eclipse 2016 based on GNSS observation

    Science.gov (United States)

    Husin, A.; Jiyo; Anggarani, S.; Ekawati, S.; Dear, V.

    2016-11-01

    A total solar eclipse occurred over Indonesia in the morning hours on 9 March 2016. Ionisations in the ionosphere which is associated with the solar radiation during the total eclipse provided a good opportunity to study the ionospheric irregularities. Using global navigation satellite system (GNSS) data taken from dual-frequency receivers in Manado, we investigated and analysed the total electron content (TEC) perturbations with a time resolution of 60 s to reveal ionospheric irregularities during total eclipse. Result showed that TEC conditions based on IPP were decreased during solar eclipse on March 9, comparing with the neighbour day. The maximum percentage deviation (DTEC) from the average value during eclipse period, 00:00 - 02:40 UT reach -41.5%. The duration of maximum decrement in TEC occurs were around 2-30 minutes after the maximum obscuration.

  3. Future Ground-Based Solar System Research: a Prospective Workshop Summary

    Science.gov (United States)

    Boehnhardt, H.; Käufl, H. U.

    2009-09-01

    The article tries to provide a perspective summary of the planetary science to be performed with future extremely large telescopes (ELTs) as an outcome of the workshop on ‘Future Ground-based Solar System Research: Synergies between Space Probes and Space Telescopes’ held on 8-12 September 2008 in Portoferraio on Isola d’ Elba, Italy. It addresses science cases on solar system objects that might challenge the capabilities of ELTs and that provide a major step forward in the knowledge and understanding of planetary system objects per se and all populations. We also compile high-level requirements for such telescopes and their instrumentation that should enable successful ELT usage for research on objects in the Solar System, the ‘disturbing foreground to real astronomy’.

  4. Design and Experimentation of Collector based Solar Dryer with Recirculation for Spices

    Directory of Open Access Journals (Sweden)

    Mr. Ganesh There

    2016-02-01

    Full Text Available Sun drying system is very common method of preserving agricultural product. Solar energy is used for heating of air and to dry food substance. In open sun drying food is unprotected from rain, wind-borne dirt and dust, infestation by insects, rodents and other animal. This process is practically attractive and environmentally sound. Shell life of agricultural product is improve by drying. This paper present design and construction of active solar dryer with recirculation technique. It consists of solar collector, drying chamber with netted trays and recirculation arrangement. Air is allowed through inlet and it is heated up in collector. Then it is circulated in drying chamber where it is utilize for drying. The design based on geographical location Wardha and meteorological data were obtained for proper design specification. Locally available materials were used for construction such as polyurethane glass, mild steel metal sheet, plywood sheet and insulating material.

  5. Molecular design of organic dyes based on vinylene hexylthiophene bridge for dye-sensitized solar cells

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Three donor-(π-spacer)-acceptor(D-π-A) organic dyes,containing different groups(triphenylamine,di(p-tolyl)phenylamine,and 9-octylcarbazole moieties) as electron donors,were designed and synthesized.Nanocrystalline TiO2 dye-sensitized solar cells were fabricated by using these dyes.It was found that the variation of electron donors in the D-π-A dyes played an important role in modifying and tuning photophysical properties of organic dyes.Under standard global AM 1.5 solar condition,the DSSC based on the dye D2 showed the best photovoltaic performance:a short-circuit photocurrent density(Jsc) of 13.93 mA/cm2,an open-circuit photovoltage(Voc) of 0.71 V,and a fill factor(FF) of 0.679,corresponding to solar-to-electric power conversion efficiency(η) of 6.72%.

  6. Molecular design of organic dyes based on vinylene hexylthiophene bridge for dye-sensitized solar cells

    Institute of Scientific and Technical Information of China (English)

    LIU DaXi; ZHAO Bin; SHEN Ping; HUANG Hui; LIU LiMing; TAN SongTing

    2009-01-01

    Three donor-(TT-spacer)-acceptor (D-tt-A) organic dyes,containing different groups (triphenylamine,di(p-tolyl)phenylamine,and 9-octylcarbazole moieties) as electron donors,were designed and synthesized. Nanocrystalline TiO2 dye-sensitized solar cells were fabricated by using these dyes. It was found that the variation of electron donors in the D-tt-A dyes played an important role in modifying and tuning photophysical properties of organic dyes. Under standard global AM 1.5 solar condition,the DSSC based on the dye D2 showed the best photovoltaic performance: a short-circuit photocurrent density (Jsc) of 13.93 mA/cm2,an open-circuit photovoltage (Voc) of 0.71 V,and a fill factor (FF) of 0.679,corresponding to solar-to-electric power conversion efficiency (77) of 6.72%.

  7. Solar flare impact on FUV based thermospheric O/N2 estimation

    Science.gov (United States)

    Zhang, Y.; Paxton, L. J.; Kil, H.

    2016-09-01

    During/after intense solar flares, FUV based thermospheric O/N2 ratio decreases and recovers instantly, indicating that the decrease is not physical. Simulations with an increased solar X-ray (0-10 nm) flux and a fixed O and N2 profiles show a significant 135.6 nm/LBHS decrease that is sufficient to explain the O/N2 decrease. The false O/N2 decrease is mostly due to increased differences in O2 absorption at 135.6 nm and LBHS caused by low-altitude emissions associated with enhanced X-rays. However, the heating from solar flares may cause a weak depletion in O/N2.

  8. Statistical Properties of Solar Active Regions Based on Objective Detection and Characterization

    Science.gov (United States)

    Zhang, Jie

    2010-05-01

    We present a study of the statistical properties of solar magnetic regions based on objective detection and characterization. The uniformity and consistency of the magnetogram images provided by SOHO/MDI make it an ideal database for automated detection of solar magnetic features. The results of detection are mainly controlled by the following four parameters or thresholds: (1) magnetic intensity threshold of kernel pixels (to find strong field regions), (2) erosion size threshold for morphological opening operation (to remove small patches), (3) magnetic intensity threshold of AR pixels (to recover the whole size of an AR), (4) dilation size threshold for morphological closing operation (to merge neighboring patches to form a whole AR). We find that the best combination of the above four parameters is (1) 250 Gauss, (2) 10 Mm, (3) 50 Gauss, and (4) 10 Mm, which yields a detection of 1772 ARs that is most similar to the NOAA catalog based on human operators; as a comparison, NOAA/SWPC reports 2281 ARs during the same period. By varying the values of the control parameters, the number of ARs detected can range from as small as 1000 to as large as 10000. With these data, we are now able to make detailed statistical study of solar active regions, including (1) how AR number and emerged magnetic flux vary with solar cycle? (2) how AR number and emerged magnetic flux vary with latitude during different phases of solar cycle? (3) the distribution of AR number with respect to the size; Is the distribution power-law, Gaussian or log-normal, and the implication on the mechanisms of generating ARs? Is there a north-south asymmetry of ARs? How the strong magnetic patches distribute within an AR? This study provides us new insights on the properties and generations of solar active regions.

  9. Comparison of Historical Satellite-Based Estimates of Solar Radiation Resources with Recent Rotating Shadowband Radiometer Measurements: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Myers, D. R.

    2009-03-01

    The availability of rotating shadow band radiometer measurement data at several new stations provides an opportunity to compare historical satellite-based estimates of solar resources with measurements. We compare mean monthly daily total (MMDT) solar radiation data from eight years of NSRDB and 22 years of NASA hourly global horizontal and direct beam solar estimates with measured data from three stations, collected after the end of the available resource estimates.

  10. Bismuth Based Hybrid Perovskites A3Bi2 I9 (A: Methylammonium or Cesium) for Solar Cell Application.

    Science.gov (United States)

    Park, Byung-Wook; Philippe, Bertrand; Zhang, Xiaoliang; Rensmo, Håkan; Boschloo, Gerrit; Johansson, Erik M J

    2015-11-18

    Low-toxic bismuth-based perovskites are prepared for the possible replacement of lead perovskite in solar cells. The perovskites have a hexagonal crystalline phase and light absorption in the visible region. A power conversion efficiency of over 1% is obtained for a solar cell with Cs3 Bi2 I9 perovskite, and it is concluded that bismuth perovskites have very promising properties for further development in solar cells.

  11. Molecular Monolayers for Electrical Passivation and Functionalization of Silicon-Based Solar Energy Devices.

    Science.gov (United States)

    Veerbeek, Janneke; Firet, Nienke J; Vijselaar, Wouter; Elbersen, Rick; Gardeniers, Han; Huskens, Jurriaan

    2017-01-11

    Silicon-based solar fuel devices require passivation for optimal performance yet at the same time need functionalization with (photo)catalysts for efficient solar fuel production. Here, we use molecular monolayers to enable electrical passivation and simultaneous functionalization of silicon-based solar cells. Organic monolayers were coupled to silicon surfaces by hydrosilylation in order to avoid an insulating silicon oxide layer at the surface. Monolayers of 1-tetradecyne were shown to passivate silicon micropillar-based solar cells with radial junctions, by which the efficiency increased from 8.7% to 9.9% for n(+)/p junctions and from 7.8% to 8.8% for p(+)/n junctions. This electrical passivation of the surface, most likely by removal of dangling bonds, is reflected in a higher shunt resistance in the J-V measurements. Monolayers of 1,8-nonadiyne were still reactive for click chemistry with a model catalyst, thus enabling simultaneous passivation and future catalyst coupling.

  12. Three-Dimensional Modeling of the Solar Wind: From the Coronal Base to the Outer Heliosphere

    Science.gov (United States)

    Usmanov, A. V; Goldstein, M. L.; Matthaeus, W. H.

    2011-01-01

    We have developed a global fully three-dimensional magnetohydrodynamic solar wind model for the region that extends from the coronal base to 100 AU. The simulation domain consists of tree spherical shell subdomains with computational boundaries between them placed at 20 solar radii and 0.3 AU. The location of the first boundary ensures that the flow at the boundary is both supersonic and super-Alfvenic. A steady-state solution in the innermost (coronal) region is obtained by the time-relaxation method. The solution uses a tilted dipole model or solar magnetograms as the boundary condition at the coronal base and includes a flux of Alfven waves in the WKB approximation which provide additional acceleration for the coronal outflow in the open field regions. The intermediate region solution is constructed by the integration of steady-state equations along radius using a marching scheme. The outer region solution (0.3-100 AU) is obtained again by the time relaxation and takes into account turbulence transport and heating as well as heating, flow deceleration, and other effects due to the interstellar pickup protons treated as a separate fluid. We use the model to simulate the global steady-state structure of the solar wind from the coronal base to the heliospheric boundary and compare the results with Ulysses and Voyager observations.

  13. Ground-based Observations of the Solar Sources of Space Weather (Invited Review)

    CERN Document Server

    Veronig, Astrid M

    2016-01-01

    Monitoring of the Sun and its activity is a task of growing importance in the frame of space weather research and awareness. Major space weather disturbances at Earth have their origin in energetic outbursts from the Sun: solar flares, coronal mass ejections and associated solar energetic particles. In this review we discuss the importance and complementarity of ground-based and space-based observations for space weather studies. The main focus is drawn on ground-based observations in the visible range of the spectrum, in particular in the diagnostically manifold H$\\alpha$ spectral line, which enables us to detect and study solar flares, filaments, filament eruptions, and Moreton waves. Existing H$\\alpha$ networks such as the GONG and the Global High-Resolution H$\\alpha$ Network are discussed. As an example of solar observations from space weather research to operations, we present the system of real-time detection of H$\\alpha$ flares and filaments established at Kanzelh\\"ohe Observatory (KSO; Austria) in the...

  14. A ~ 12 kpc HI extension and other HI asymmetries in the isolated galaxy CIG 340 (IC 2487)

    CERN Document Server

    Scott, T C; Montenegro, L Verdes; Bosma, A; Athanassoula, E; Sulentic, J; Espada, D; Yun, M S; Argudo-Fernandez, M

    2014-01-01

    HI kinematic asymmetries are common in late-type galaxies irrespective of environment, although the amplitudes are strikingly low in isolated galaxies. As part of our studies of the HI morphology and kinematics in isolated late-type galaxies we have chosen several very isolated galaxies from the AMIGA sample for HI mapping. Here we present GMRT 21-cm HI line mapping of CIG 340 which was selected because its integrated HI spectrum has a very symmetric profile, Aflux = 1.03. Optical images of the galaxy hinted at a warped disk in contrast to the symmetric integrated HI spectrum profile. Our aim is to determine the extent to which the optical asymmetry is reflected in the resolved HI morphology and kinematics. GMRT observations reveal significant HI morphological asymmetries in CIG 340 despite it's overall symmetric optical form and highly symmetric HI spectrum. The most notable HI features are: 1) a warp in the HI disk (with an optical counterpart), 2) the HI north/south flux ratio = 1.32 is much larger than ex...

  15. Recycling of indium from CIGS photovoltaic cells: potential of combining acid-resistant nanofiltration with liquid-liquid extraction.

    Science.gov (United States)

    Zimmermann, Yannick-Serge; Niewersch, Claudia; Lenz, Markus; Kül, Zöhre Zohra; Corvini, Philippe F-X; Schäffer, Andreas; Wintgens, Thomas

    2014-11-18

    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 their primary ores. Indium is of foremost interest being widely used, expensive, scarce and prone to supply risk. This study first investigated the capability of different nanofiltration membranes of extracting indium from copper-indium-gallium- selenide photovoltaic cell (CIGS) leachates under low pH conditions and low transmembrane pressure differences (98% by nanofiltration, separating it from parts of the Ag, Sb, Se, and Zn present. LLE using di-(2-ethylhexyl)phosphoric acid (D2EHPA) extracted 97% of the indium from the retentates, separating it from all other elements except for Mo, Al, and Sn. Overall, 95% (2.4 g m(-2) CIGS) of the indium could be extracted to the D2EHPA phase. Simultaneously, by nanofiltration the consumption of D2EHPA was reduced by >60% due to the metal concentration in the reduced retentate volume. These results show clearly the potential for efficient scarce metal recovery from secondary resources. Furthermore, since nanofiltration was applicable at very low pH (≥ 0.6), it may be applied in hydrometallurgy typically using acidic conditions.

  16. Cobalt-Based Electrolytes for Dye-Sensitized Solar Cells: Recent Advances towards Stable Devices

    Directory of Open Access Journals (Sweden)

    Federico Bella

    2016-05-01

    Full Text Available Redox mediators based on cobalt complexes allowed dye-sensitized solar cells (DSCs to achieve efficiencies exceeding 14%, thus challenging the emerging class of perovskite solar cells. Unfortunately, cobalt-based electrolytes demonstrate much lower long-term stability trends if compared to the traditional iodide/triiodide redox couple. In view of the large-scale commercialization of cobalt-based DSCs, the scientific community has recently proposed various approaches and materials to increase the stability of these devices, which comprise gelling agents, crosslinked polymeric matrices and mixtures of solvents (including water. This review summarizes the most significant advances recently focused towards this direction, also suggesting some intriguing way to fabricate third-generation cobalt-based photoelectrochemical devices stable over time.

  17. Solar paint of ZnO/CdS and ZnO/CdSe based on commercial ZnO

    Science.gov (United States)

    Guo, Yi; Zhang, Xiang; Li, Yanhong; Li, Yanmei; Hu, Chunli; Zhou, Xingfu

    2016-03-01

    We report a facile and cheap route to the fabrication of ZnO/CdS and ZnO/CdSe based on commercial ZnO particles. The obtained product can be directly brush printed as solar paint. The results show that the solar cell based on the mixture of ZnO/CdS and ZnO/CdSe have a better light absorption and electron transport ability, and a high power conversion efficiency (PCE) of 1.36% was obtained, which is the highest PCE reported for inorganic paint-based solar cells to date. This method greatly simplifies the process of the solar cell fabrication and opens a door toward the cheap and printable solar paint based on commercial available materials.

  18. Pose Self-Measurement of Noncooperative Spacecraft Based on Solar Panel Triangle Structure

    OpenAIRE

    Jingzhou Song; Caixiu Cao

    2015-01-01

    Aiming at the recognition and location of noncooperative spacecraft, this paper presents a monocular vision pose measurement method based on solar triangle structure. First of all, an autonomous recognition algorithm of feature structure based on sliding window Hough transformation (SWHT) and inscribed circle of a triangle is proposed, and the image coordinates of feature points on the triangle can be obtained relying on this algorithm, combined with the P4P algorithm and the structure of spa...

  19. Superior light trapping in thin film silicon solar cells through nano imprint lithography

    Energy Technology Data Exchange (ETDEWEB)

    Soppe, W.J.; Dorenkamper, M.S.; Schropp, R.E.I.; Pex, P.P.A.C.

    2013-10-15

    ECN and partners have developed a fabrication process based on nanoimprint lithography (NIL) of textures for light trapping in thin film solar cells such as thin-film silicon, OPV, CIGS and CdTe. The process can be applied in roll-to-roll mode when using a foil substrate or in roll-to-plate mode when using a glass substrate. The lacquer also serves as an electrically insulating layer for cells if steel foil is used as substrate, to enable monolithic series interconnection. In this paper we will show the superior light trapping in thin film silicon solar cells made on steel foil with nanotextured back contacts. We have made single junction a-Si and {mu}c-Si and a-Si/{mu}c-Si tandem cells, where we applied several types of nano-imprints with random and periodic structures. We will show that the nano-imprinted back contact enables more than 30% increase of current in comparison with non-textured back contacts and that optimized periodic textures outperform state-of-the-art random textures. For a-Si cells we obtained Jsc of 18 mA/cm{sup 2} and for {mu}c-Si cells more than 24 mA/cm{sup 2}. Tandem cells with a total Si absorber layer thickness of only 1350 nm have an initial efficiency of 11%.

  20. One-dimension-based spatially ordered architectures for solar energy conversion.

    Science.gov (United States)

    Liu, Siqi; Tang, Zi-Rong; Sun, Yugang; Colmenares, Juan Carlos; Xu, Yi-Jun

    2015-08-07

    The severe consequences of fossil fuel consumption have resulted in a need for alternative sustainable sources of energy. Conversion and storage of solar energy via a renewable method, such as photocatalysis, holds great promise as such an alternative. One-dimensional (1D) nanostructures have gained attention in solar energy conversion because they have a long axis to absorb incident sunlight yet a short radial distance for separation of photogenerated charge carriers. In particular, well-ordered spatially high dimensional architectures based on 1D nanostructures with well-defined facets or anisotropic shapes offer an exciting opportunity for bridging the gap between 1D nanostructures and the micro and macro world, providing a platform for integration of nanostructures on a larger and more manageable scale into high-performance solar energy conversion applications. In this review, we focus on the progress of photocatalytic solar energy conversion over controlled one-dimension-based spatially ordered architecture hybrids. Assembly and classification of these novel architectures are summarized, and we discuss the opportunity and future direction of integration of 1D materials into high-dimensional, spatially organized architectures, with a perspective toward improved collective performance in various artificial photoredox applications.

  1. Enhanced photocurrent density in graphene/Si based solar cell (GSSC) by optimizing active layer thickness

    Energy Technology Data Exchange (ETDEWEB)

    Rosikhin, Ahmad, E-mail: a.rosikhin86@yahoo.co.id; Hidayat, Aulia Fikri; Syuhada, Ibnu; Winata, Toto, E-mail: toto@fi.itb.ac.id [Department of physics, physics of electronic materials research division Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung Jl. Ganesha 10, Bandung 40132, Jawa Barat – Indonesia (Indonesia)

    2015-12-29

    Thickness dependent photocurrent density in active layer of graphene/Si based solar cell has been investigated via analytical – simulation study. This report is a preliminary comparison of experimental and analytical investigation of graphene/Si based solar cell. Graphene sheet was interfaced with Si thin film forming heterojunction solar cell that was treated as a device model for photocurrent generator. Such current can be enhanced by optimizing active layer thickness and involving metal oxide as supporting layer to shift photons absorption. In this case there are two type of devices model with and without TiO{sub 2} in which the silicon thickness varied at 20 – 100 nm. All of them have examined and also compared with each other to obtain an optimum value. From this calculation it found that generated currents almost linear with thickness but there are saturated conditions that no more enhancements will be achieved. Furthermore TiO{sub 2} layer is effectively increases photon absorption but reducing device stability, maximum current is fluctuates enough. This may caused by the disturbance of excitons diffusion and resistivity inside each layer. Finally by controlling active layer thickness, it is quite useful to estimate optimization in order to develop the next solar cell devices.

  2. Temperature-based estimation of global solar radiation using soft computing methodologies

    Science.gov (United States)

    Mohammadi, Kasra; Shamshirband, Shahaboddin; Danesh, Amir Seyed; Abdullah, Mohd Shahidan; Zamani, Mazdak

    2016-07-01

    Precise knowledge of solar radiation is indeed essential in different technological and scientific applications of solar energy. Temperature-based estimation of global solar radiation would be appealing owing to broad availability of measured air temperatures. In this study, the potentials of soft computing techniques are evaluated to estimate daily horizontal global solar radiation (DHGSR) from measured maximum, minimum, and average air temperatures ( T max, T min, and T avg) in an Iranian city. For this purpose, a comparative evaluation between three methodologies of adaptive neuro-fuzzy inference system (ANFIS), radial basis function support vector regression (SVR-rbf), and polynomial basis function support vector regression (SVR-poly) is performed. Five combinations of T max, T min, and T avg are served as inputs to develop ANFIS, SVR-rbf, and SVR-poly models. The attained results show that all ANFIS, SVR-rbf, and SVR-poly models provide favorable accuracy. Based upon all techniques, the higher accuracies are achieved by models (5) using T max- T min and T max as inputs. According to the statistical results, SVR-rbf outperforms SVR-poly and ANFIS. For SVR-rbf (5), the mean absolute bias error, root mean square error, and correlation coefficient are 1.1931 MJ/m2, 2.0716 MJ/m2, and 0.9380, respectively. The survey results approve that SVR-rbf can be used efficiently to estimate DHGSR from air temperatures.

  3. n +-Microcrystalline-Silicon Tunnel Layer in Tandem Si-Based Thin Film Solar Cells

    Science.gov (United States)

    Lee, Ching-Ting; Lee, Hsin-Ying; Chen, Kuan-Hao

    2016-10-01

    In this study, the p-SiC/ i-Si/ n-Si cell and the p-SiC/ i-SiGe/ n-Si cell deposited using plasma-enhanced chemical vapor deposition were cascaded for forming the tandem Si-based thin film solar cells to absorb the wide solar spectrum. To further improve the performances of the tandem Si-based thin film solar cells, a 5-nm-thick n +-microcrystalline-Si ( n +-μc-Si) tunnel layer deposited using the laser-assisted plasma-enhanced chemical vapor deposition was inserted between the p-SiC/ i-Si/ n-Si cell and the p-SiC/ i-SiGe/ n-Si cell. Since both the plasma and the CO2 laser were simultaneously utilized to efficiently decompose the reactant and doping gases, the carrier concentration and the carrier mobility of the n +-μc-Si tunnel layer were significantly improved. The ohmic contact formed between the p-SiC layer and the n +-μc-Si tunnel layer with low resistance was beneficial to the generated current transportation and the carrier recombination rate. Therefore, the conversion efficiency of the tandem solar cells was promoted from 8.57% and 8.82% to 9.91% compared to that without tunnel layer and with 5-nm-thick n +-amorphous-Si tunnel layer.

  4. Reconstruction of the solar EUV irradiance from 1996 to 2010 based on SOHO/EIT images

    Directory of Open Access Journals (Sweden)

    Haberreiter Margit

    2014-01-01

    Full Text Available The solar Extreme UltraViolet (EUV spectrum has important effects on the Earth’s upper atmosphere. For a detailed investigation of these effects it is important to have a consistent data series of the EUV spectral irradiance available. We present a reconstruction of the solar EUV irradiance based on SOHO/EIT images, along with synthetic spectra calculated using different coronal features which represent the brightness variation of the solar atmosphere. The EIT images are segmented with the SPoCA2 tool which separates the features based on a fixed brightness classification scheme. With the SOLMOD code we then calculate intensity spectra for the 10–100 nm wavelength range and each of the coronal features. Weighting the intensity spectra with the area covered by each of the features yields the temporal variation of the EUV spectrum. The reconstructed spectrum is then validated against the spectral irradiance as observed with SOHO/SEM. Our approach leads to good agreement between the reconstructed and the observed spectral irradiance. This study is an important step toward understanding variations in the solar EUV spectrum and ultimately its effect on the Earth’s upper atmosphere.

  5. All-solid, flexible solar textiles based on dye-sensitized solar cells with ZnO nanorod arrays on stainless steel wires

    Energy Technology Data Exchange (ETDEWEB)

    Chae, Youngjin [Department of Clothing and Textiles, Yonsei University, 262 Seongsanno, Seodaemun-gu, Seoul 120-749 (Korea, Republic of); Park, Jung Tae; Koh, Jong Kwan [Department of Chemical and Biomolecular Engineering, Yonsei University, 262 Seongsanno, Seodaemun-gu, Seoul 120-749 (Korea, Republic of); Kim, Jong Hak, E-mail: jonghak@yonsei.ac.kr [Department of Chemical and Biomolecular Engineering, Yonsei University, 262 Seongsanno, Seodaemun-gu, Seoul 120-749 (Korea, Republic of); Kim, Eunae, E-mail: eakim@yonsei.ac.kr [Department of Clothing and Textiles, Yonsei University, 262 Seongsanno, Seodaemun-gu, Seoul 120-749 (Korea, Republic of)

    2013-10-01

    Highlights: • All-solid, flexible solar textile fabricated with DSSCs is demonstrated. • DSSCs woven into a satin structure and transparent PET film are used. • Solar textile showed a high efficiency of 2.57%. -- Abstract: An all-solid, flexible solar textile fabricated with dye-sensitized solar cells (DSSCs) woven into a satin structure and transparent poly(ethylene terephthalate) (PET) film was demonstrated. A ZnO nanorod (NR) vertically grown from fiber-type conductive stainless steel (SS) wire was utilized as a photoelectrode, and a Pt-coated SS wire was used as a counter electrode. A graft copolymer, i.e. poly(vinyl chloride)-graft-poly(oxyethylene methacrylate) (PVC-g-POEM) was synthesized via atom transfer radical polymerization (ATRP) and used as a solid electrolyte. The conditions for the growth of ZnO NR and sufficient dye loading were investigated to improve cell performance. The adhesion of PET films to DSSCs resulted in physical stability improvements without cell performance loss. The solar textile with 10 × 10 wires exhibited an energy conversion efficiency of 2.57% with a short circuit current density of 20.2 mA/cm{sup 2} at 100 mW/cm{sup 2} illumination, which is the greatest account of an all-solid, ZnO-based flexible solar textile. DSSC textiles with woven structures are applicable to large-area, roll-to-roll processes.

  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. Comparative Study of Zn(O,S) Buffer Layers and CIGS Solar Cells Fabricated by CBD, ALD, and Sputtering: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Ramanathan, K.; Mann, J.; Glynn, S.; Christensen, S.; Pankow, J.; Li, J.; Scharf, J.; Mansfield, L. M.; Contreras, M. A.; Noufi, R.

    2012-06-01

    Zn(O,S) thin films were deposited by chemical bath deposition (CBD), atomic layer deposition, and sputtering. Composition of the films and band gap were measured and found to follow the trends described in the literature. CBD Zn(O,S) parameters were optimized and resulted in an 18.5% efficiency cell that did not require post annealing, light soaking, or an undoped ZnO layer. Promising results were obtained with sputtering. A 13% efficiency cell was obtained for a Zn(O,S) emitter layer deposited with 0.5%O2. With further optimization of process parameters and an analysis of the loss mechanisms, it should be possible to increase the efficiency.

  8. Role of the buffer solution in the chemical deposition of CdS films for CIGS solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sooho; Kim, Donguk; Baek, Dohyun; Hong, Byoungyou; Yi, Junsin; Lee, Jaehyeong [Sungkyunkwan University, Suwon (Korea, Republic of); Park, Yongseob [Chosun College of Science and and Technology, Gwangju (Korea, Republic of); Choi, Wonseok [Hanbat National University, Daejeon (Korea, Republic of)

    2014-05-15

    In this work, the effects of NH{sub 4}Ac on the structural and the electro-optical properties of CdS films were investigated. CdS thin films were deposited on soda-lime glass and indium-tin-oxide (ITO) coated glass from a chemical bath containing 0.025 M cadmium acetate, 0 M ∼ 0.2 M ammonium acetate, 0.5 M thiourea, and ammonia. Cadmium acetate was the cadmium source, ammonium acetate served as a buffer, ammonia was the complexing agent, and thiourea was the source of sulfur. A commonly- available chemical bath deposition system was successfully modified to obtain precise control over the pH of the solution at 75 .deg. C during the deposition. Chemically deposited CdS films were studied by using field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), optical transmittance, and electrical resistivity measurements.

  9. Benzotrithiophene-Based Hole-Transporting Materials for 18.2 % Perovskite Solar Cells.

    Science.gov (United States)

    Molina-Ontoria, Agustín; Zimmermann, Iwan; Garcia-Benito, Inés; Gratia, Paul; Roldán-Carmona, Cristina; Aghazada, Sadig; Graetzel, Michael; Nazeeruddin, Mohammad Khaja; Martín, Nazario

    2016-05-17

    New star-shaped benzotrithiophene (BTT)-based hole-transporting materials (HTM) BTT-1, BTT-2 and BTT-3 have been obtained through a facile synthetic route by crosslinking triarylamine-based donor groups with a benzotrithiophene (BTT) core. The BTT HTMs were tested on solution-processed lead trihalide perovskite-based solar cells. Power conversion efficiencies in the range of 16 % to 18.2 % were achieved under AM 1.5 sun with the three derivatives. These values are comparable to those obtained with today's most commonly used HTM spiro-OMeTAD, which point them out as promising candidates to be used as readily available and cost-effective alternatives in perovskite solar cells (PSCs).

  10. Optimal allocation of solar based distributed generators in distribution system using Bat algorithm

    Directory of Open Access Journals (Sweden)

    Suresh Kumar Sudabattula

    2016-09-01

    Full Text Available With increased demand of electrical energy, limited availability of fossil fuels and environmental concerns, it is necessary to consider renewable energy based generation in a power system network. Optimal allocation of renewable based distributed generators in the distribution system is a challenging task in the recent years. In this paper an effective technique is proposed for optimal allocation of solar based distributed generators in the distribution network using a Bat algorithm (BA is presented. The objective is to minimize power loss of radial distribution system. Different operating constraints related to the distribution network are considered. The stochastic nature of solar irradiance is modeled by using suitable probability distribution function (PDF. The proposed method is tested and validated on IEEE 33 bus test system.

  11. Quasi-Solid-State Dye-Sensitized Solar Cells based on Mesoporous Silica SBA-15 Framework Materials

    Institute of Scientific and Technical Information of China (English)

    YANG Hong; CHENG Yun-Fei; LI Fu-You; ZHOU Zhi-Guo; YI Tao; HUANG Chun-Hui; JIA Neng-Qin

    2005-01-01

    @@ We develop a novel and efficient quasi-solid-state electrolyte based on the mesoporous silica SBA-15 as a framework material for a dye sensitized nanocrystalline TiO2 solar cell. A solar energy-to-electricity conversion efficiency of 4.34% is achieved under AM 1.5 illumination (100mW/cm2).

  12. Fully solution-processed transparent electrodes based on silver nanowire composites for perovskite solar cells

    Science.gov (United States)

    Kim, Areum; Lee, Hongseuk; Kwon, Hyeok-Chan; Jung, Hyun Suk; Park, Nam-Gyu; Jeong, Sunho; Moon, Jooho

    2016-03-01

    We report all-solution-processed transparent conductive electrodes based on Ag nanowire (AgNW)-embedded metal oxide composite films for application in organometal halide perovskite solar cells. To address the thermal instability of Ag nanowires, we used combustive sol-gel derived thin films to construct ZnO/ITO/AgNW/ITO composite structures. The resulting composite configuration effectively prevented the AgNWs from undergoing undesirable side-reactions with halogen ions present in the perovskite precursor solutions that significantly deteriorate the optoelectrical properties of Ag nanowires in transparent conductive films. AgNW-based composite electrodes had a transmittance of ~80% at 550 nm and sheet resistance of 18 Ω sq-1. Perovskite solar cells fabricated using a fully solution-processed transparent conductive electrode, Au/spiro-OMeTAD/CH3NH3PbI3 + m-Al2O3/ZnO/ITO/AgNW/ITO, exhibited a power conversion efficiency of 8.44% (comparable to that of the FTO/glass-based counterpart at 10.81%) and were stable for 30 days in ambient air. Our results demonstrate the feasibility of using AgNWs as a transparent bottom electrode in perovskite solar cells produced by a fully printable process.We report all-solution-processed transparent conductive electrodes based on Ag nanowire (AgNW)-embedded metal oxide composite films for application in organometal halide perovskite solar cells. To address the thermal instability of Ag nanowires, we used combustive sol-gel derived thin films to construct ZnO/ITO/AgNW/ITO composite structures. The resulting composite configuration effectively prevented the AgNWs from undergoing undesirable side-reactions with halogen ions present in the perovskite precursor solutions that significantly deteriorate the optoelectrical properties of Ag nanowires in transparent conductive films. AgNW-based composite electrodes had a transmittance of ~80% at 550 nm and sheet resistance of 18 Ω sq-1. Perovskite solar cells fabricated using a fully solution

  13. A Fractionated Space Weather Base at L5 using CubeSats and Solar Sails

    Science.gov (United States)

    Liewer, Paulett C.; Klesh, A.; Lo, M.; Murphy, N.; Staehle, R. L.; Vourlidas, A.; Cutler, J. W.; Lightsey, G.

    2013-07-01

    The Sun-Earth L5 Lagrange point is an ideal location for an operational space weather mission to provide early warning of Earth-directed solar storms (CMEs, shocks and associated solar energetic particles) so the effects on power grids, spacecraft and communications systems can be mitigated. Such missions have been proposed using conventional spacecraft and chemical propulsion at costs of hundreds of millions of dollars. Here we describe a mission that can accomplish the goals at a much lower cost by dividing the payload among a cluster of interplanetary CubeSats that reach orbits around L5 using solar sails. The ascendancy of CubeSats has brought renewed interest in solar sail propulsion because sail area scales directly with spacecraft mass. The concept presented here draws heavily on a NIAC study (Staehle et al., AIAA, 2012) that developed a 6U CubeSat architecture for interplanetary missions. This study allocated 2U for a solar sail; the sail system was based on the Planetary Society’s LightSail-1TM architecture. At a recent workshop on small satellites, hosted by the Keck Institute for Space Studies, a concept was developed for a fractionated Space Weather Base (SWB) at L5. In this concept, a loose formation of CubeSats, each ~6U in size and each carrying a portion of the science payload, can accomplish, at a much reduced cost, many of the goals of a conventional single-spacecraft L5 mission, as described in the 2013 NRC Solar and Space Physics Decadal report. Each of the small ~6U interplanetary CubeSats reaches an orbit around L5 using its own solar sail of approximately 64 m2 which fits in ~2U. Key to the mission is that only one of the CubeSats carries a high-gain antenna and other hardware necessary for sending high-rate science data to Earth. The other CubeSats, in addition to carrying one or two science instruments, carry a much smaller communication system to send the science data to the communication hub and low-rate engineering data to Earth. The

  14. 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.

  15. A comparison of data from SOLMET/ERSATZ and the National Solar Radiation Data Base

    Energy Technology Data Exchange (ETDEWEB)

    Marion, W; Myers, D

    1992-11-01

    This report compares data from the new National Solar Radiation Data Base (NSRDB) with data from the earlier SOLMET/ERSATZ data base. It compares the two data bases, station-by-station, with respect to their long-term average daily values of global horizontal and direct normal solar radiation. We conclude that on an annual basis, NSRDB values for global horizontal radiation are within {plus_minus}5% of SOLMET/ERSATZ values for 60% of the stations, more than 5% greater than the SOLMET/ERSATZ values for 30% of the stations, and more than 5% less than the SOLMET/ERSATZ values for 10% of the stations. On an annual basis for direct nominal radiation, the NSRDB values are with {plus_minus}5% of the SOLMET/ERSATZ data for only 40% of the stations, more than 5% greater than the SOLMET/ERSATZ values for 45% of the stations, and more than 5% less than the SOLMET/ERSATZ values for 15% of the stations. In general, the NSRDB shows higher values of solar radiation for the eastern United States, particularly the Northeast, and lower values for some of the western states (Arizona, Colorado, Idaho, Nevada, New Mexico, Utah, and Wyoming). However, because some of the stations within a state show higher values of solar radiation while others show lower values, this generalization may be misleading when concerned with a particular station. Consequently, the appendices provide tables showing a station-by-station comparison of the NSRDB and SOLMET/ERSATZ data. In addition to comparing annual values, the tables compare the two data bases for the months of August and December. This comparison shows larger differences between the two data bases for December.

  16. Low-Pressure Vapor-Assisted Solution Process for Thiocyanate-Based Pseudohalide Perovskite Solar Cells.

    Science.gov (United States)

    Chiang, Yu-Hsien; Cheng, Hsin-Min; Li, Ming-Hsien; Guo, Tzung-Fang; Chen, Peter

    2016-09-22

    In this report, we fabricated thiocyanate-based perovskite solar cells with low-pressure vapor-assisted solution process (LP-VASP) method. Photovoltaic performances are evaluated with detailed materials characterizations. Scanning electron microscopy images show that SCN-based perovskite films fabricated using LP-VASP have long-range uniform morphology and large grain sizes up to 1 μm. The XRD and Raman spectra were employed to observe the characteristic peaks for both SCN-based and pure CH3 NH3 PbI3 perovskite. We observed that the Pb(SCN)2 film transformed to PbI2 before the formation of perovskite film. X-ray photoemission spectra (XPS) show that only a small amount of S remained in the film. Using LP-VASP method, we fabricated SCN-based perovskite solar cells and achieved a power conversion efficiency of 12.72 %. It is worth noting that the price of Pb(SCN)2 is only 4 % of PbI2 . These results demonstrate that pseudo-halide perovskites are promising materials for fabricating low-cost perovskite solar cells.

  17. Intensification of depolymerization of polyacrylic acid solution using different approaches based on ultrasound and solar irradiation with intensification studies.

    Science.gov (United States)

    Prajapat, Amrutlal L; Gogate, Parag R

    2016-09-01

    Depolymerization of polyacrylic acid (PAA) as sodium salt has been investigated using ultrasonic and solar irradiations with process intensification studies based on combination with hydrogen peroxide (H2O2) and ozone (O3). Effect of solar intensity, ozone flow and ultrasonic power dissipation on the extent of viscosity reduction has been investigated for individual treatment approaches. The combined approaches such as US+solar, solar+O3, solar+H2O2, US+H2O2 and US+O3 have been subsequently investigated under optimum conditions and established to be more efficient as compared to individual approaches. Approach based on US (60W)+solar+H2O2 (0.01%) resulted in the maximum extent of viscosity reduction as 98.97% in 35min whereas operation of solar+H2O2 (0.01%), US (60W), H2O2 (0.3%) and solar irradiation resulted in about 98.08%, 90.13%, 8.91% and 90.77% intrinsic viscosity reduction in 60min respectively. Approach of US (60W)+solar+ozone (400mg/h flow rate) resulted in extent of viscosity reduction as 99.47% in 35min whereas only ozone (400mg/h flow rate), ozone (400mg/h flow rate)+US (60W) and ozone (400mg/h flow rate)+solar resulted in 69.04%, 98.97% and 98.51% reduction in 60min, 55min and 55min respectively. The chemical identity of the treated polymer using combined approaches was also characterized using FTIR (Fourier transform infrared) spectra and it was established that no significant structural changes were obtained during the treatment. Overall, it can be said that the combination technique based on US and solar irradiations in the presence of hydrogen peroxide is the best approach for the depolymerization of PAA solution.

  18. Design of DSP-based high-power digital solar array simulator

    Science.gov (United States)

    Zhang, Yang; Liu, Zhilong; Tong, Weichao; Feng, Jian; Ji, Yibo

    2013-12-01

    To satisfy rigid performance specifications, a feedback control was presented for zoom optical lens plants. With the increasing of global energy consumption, research of the photovoltaic(PV) systems get more and more attention. Research of the digital high-power solar array simulator provides technical support for high-power grid-connected PV systems research.This paper introduces a design scheme of the high-power digital solar array simulator based on TMS320F28335. A DC-DC full-bridge topology was used in the system's main circuit. The switching frequency of IGBT is 25kHz.Maximum output voltage is 900V. Maximum output current is 20A. Simulator can be pre-stored solar panel IV curves.The curve is composed of 128 discrete points .When the system was running, the main circuit voltage and current values was feedback to the DSP by the voltage and current sensors in real-time. Through incremental PI,DSP control the simulator in the closed-loop control system. Experimental data show that Simulator output voltage and current follow a preset solar panels IV curve. In connection with the formation of high-power inverter, the system becomes gridconnected PV system. The inverter can find the simulator's maximum power point and the output power can be stabilized at the maximum power point (MPP).

  19. Petascale Computing for Ground-Based Solar Physics with the DKIST Data Center

    Science.gov (United States)

    Berukoff, Steven J.; Hays, Tony; Reardon, Kevin P.; Spiess, DJ; Watson, Fraser; Wiant, Scott

    2016-05-01

    When construction is complete in 2019, the Daniel K. Inouye Solar Telescope will be the most-capable large aperture, high-resolution, multi-instrument solar physics facility in the world. The telescope is designed as a four-meter off-axis Gregorian, with a rotating Coude laboratory designed to simultaneously house and support five first-light imaging and spectropolarimetric instruments. At current design, the facility and its instruments will generate data volumes of 3 PB per year, and produce 107-109 metadata elements.The DKIST Data Center is being designed to store, curate, and process this flood of information, while providing association of science data and metadata to its acquisition and processing provenance. The Data Center will produce quality-controlled calibrated data sets, and make them available freely and openly through modern search interfaces and APIs. Documented software and algorithms will also be made available through community repositories like Github for further collaboration and improvement.We discuss the current design and approach of the DKIST Data Center, describing the development cycle, early technology analysis and prototyping, and the roadmap ahead. We discuss our iterative development approach, the underappreciated challenges of calibrating ground-based solar data, the crucial integration of the Data Center within the larger Operations lifecycle, and how software and hardware support, intelligently deployed, will enable high-caliber solar physics research and community growth for the DKIST's 40-year lifespan.

  20. Locally linear neurofuzzy modeling and prediction of geomagnetic disturbances based on solar wind conditions

    Science.gov (United States)

    Sharifie, Javad; Lucas, Caro; Araabi, Babak N.

    2006-06-01

    Disturbance storm time index (Dst) is nonlinearly related to solar wind data. In this paper, Dst past values, Dst derivative, past values of southward interplanetary magnetic field, and the square root of dynamic pressure are used as inputs for modeling and prediction of the Dst index, especially during extreme events. The geoeffective solar wind parameters are selected depending on the physical background of the geomagnetic storm procedure and physical models. A locally linear neurofuzzy model with a progressive tree construction learning algorithm is applied as a powerful tool for nonlinear modeling of Dst index on the basis of its past values and solar wind parameters. The result for modeling and prediction of several intense storms shows that the geomagnetic disturbance Dst index based on geoeffective parameters is a nonlinear model that could be considered as the nonlinear extension of empirical linear physical models. The method is applied for prediction of some geomagnetic storms. Obtained results show that using the proposed method, the predicted values of several extreme storms are highly correlated with observed values. In addition, prediction of the main phase of many storms shows a good match with observed data, which constitutes an appropriate approach for solar storm alerting to vulnerable industries.