WorldWideScience

Sample records for thin-film solar cells

  1. Thin-film solar cell:

    OpenAIRE

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

    1998-01-01

    The invention relates to a thin-film solar cell provided with at least one p-i-n junction comprising at least one p-i junction which is at an angle alpha with that surface of the thin-film solar cell which collects light during operation and at least one i-n junction which is at an angle beta with the light-collecting surface. In this context, the relationships 45 < alpha < 135 degrees and 45 < beta < 135 degrees apply. The invention also relates to a panel provided with a plurality of such t...

  2. 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

  3. Metal nanoparticles for thin film solar cells

    DEFF Research Database (Denmark)

    Gritti, Claudia

    2014-01-01

    Among the different renewable ways to produce energy, photovoltaic cells have a big potential and the research is now focusing on getting higher efficiency and at the same time saving the manufacturing costs improving the performance of thin film solar cells. The spectral distribution in the infrared wavelength region longer than 800 nm accounts for ?40% of the entire solar energy observed on Earth, and only a few solar cells can efficiently convert solar energy with such a long wavelength. The ...

  4. Thin film solar cell technology in Germany

    International Nuclear Information System (INIS)

    Within the scope of limited nonrenewable energy resources and the limited capacity of the ecosystem for greenhouse gases and nuclear waste, sustainability is one important target in the future. Different energy scenarios showed the huge potential for photovoltaics (PV) to solve this energy problem. Nevertheless, in the last decade, PV had an average growth rate of over 20% per year. In 2002, the solar industry delivered more than 500 MWp/year of photovoltaic generators [A. Jaeger-Waldau, A European Roadmap for PV R and D, E-MRS Spring Meeting, (2003)]. More than 85% of the current production involves crystalline silicon technologies. These technologies still have a high cost reduction potential, but this will be limited by the silicon feedstock. On the other hand the so-called second generation thin film solar cells based on a-Si, Cu(In,Ga)(Se,S2 (CIGS) or CdTe have material thicknesses of a few microns as a result of their direct band gap. Also, the possibility of circuit integration offers an additional cost reduction potential. Especially in Germany, there are a few companies who focus on thin film solar cells. Today, there are two manufacturers with production lines: the Phototronics (PST) division of RWE-Schott Solar with a-Si thin film technology and the former Antec Solar GmbH (now Antec Solar Energy GmbH) featuring the CdTe technology. A pilot line based on CIGS technology is run by Wuerth Solar GmbH. There is also a variety of research activity at other companies, namely, at Shell Solar, Sulfurcell Solartechnik GmbH, Solarion GmbH and the CIS-Solartechnik GmbH. We will give an overview on research activity on various thin film technologies, as well as different manufacturing and production processes in the companies mentioned above. (Author)

  5. Light management in thin-film silicon solar cells:

    OpenAIRE

    Isabella, O.

    2013-01-01

    Solar energy can fulfil mankind’s energy needs and secure a more balanced distribution of primary sources of energy. Wafer-based and thin-film silicon solar cells dominate todays’ photovoltaic market because silicon is a non-toxic and abundant material and high conversion efficiencies are achieved with silicon-based solar cells. To stay competitive with bulk crystalline silicon and other thin-film solar cell technologies, thin-film silicon solar cells have to achieve a conversion efficiency ...

  6. Silicon Thin-Film Solar Cells

    Directory of Open Access Journals (Sweden)

    Guy Beaucarne

    2007-12-01

    Full Text Available We review the field of thin-film silicon solar cells with an active layer thickness of a few micrometers. These technologies can potentially lead to low cost through lower material costs than conventional modules, but do not suffer from some critical drawbacks of other thin-film technologies, such as limited supply of basic materials or toxicity of the components. Amorphous Si technology is the oldest and best established thin-film silicon technology. Amorphous silicon is deposited at low temperature with plasma-enhanced chemical vapor deposition (PECVD. In spite of the fundamental limitation of this material due to its disorder and metastability, the technology is now gaining industrial momentum thanks to the entry of equipment manufacturers with experience with large-area PECVD. Microcrystalline Si (also called nanocrystalline Si is a material with crystallites in the nanometer range in an amorphous matrix, and which contains less defects than amorphous silicon. Its lower bandgap makes it particularly appropriate as active material for the bottom cell in tandem and triple junction devices. The combination of an amorphous silicon top cell and a microcrystalline bottom cell has yielded promising results, but much work is needed to implement it on large-area and to limit light-induced degradation. Finally thin-film polysilicon solar cells, with grain size in the micrometer range, has recently emerged as an alternative photovoltaic technology. The layers have a grain size ranging from 1 μm to several tens of microns, and are formed at a temperature ranging from 600 to more than 1000∘C. Solid Phase Crystallization has yielded the best results so far but there has recently been fast progress with seed layer approaches, particularly those using the aluminum-induced crystallization technique.

  7. Thin-film solar cells

    International Nuclear Information System (INIS)

    The technological status of a-Si, CuInSe2u, CdTe, f-Si and nc-TiO2 solar cells is evaluated according to a new method that was developed together with the NOVEM. Costs per Wp, producibility, environmental and health concerns, efficiency, life expectation, applicability, and resources are evaluated. Weighing of these criteria according to their assumed importance results in a ranking of the expectations towards these technologies. The result of this evaluation is that no real winners or losers can be identified at this stage. a-Si, f-Si, and nc-TiO2 have a somewhat better perspective than CuInSe2 and CdTe. It should be mentioned, however, that the environmental and health aspects were considered to be very important. 11 figs., 16 tabs., 301 refs., 1 appendix

  8. Advanced characterization techniques for thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Abou-Ras, Daniel [Helmholtz-Zentrum Berlin fuer Materialien und Energie, Berlin (Germany); Kirchartz, Thomas [Imperial College, London (United Kingdom); Rau, Uwe (eds.) [Forschungszentrum Juelich GmbH (Germany)

    2011-07-01

    Written by scientists from leading institutes in Germany, USA and Spain who use these techniques as the core of their scientific work and who have a precise idea of what is relevant for photovoltaic devices, this book contains concise and comprehensive lecture-like chapters on specific research methods. They focus on emerging, specialized techniques that are new to the field of photovoltaics yet have a proven relevance. This book is structured as follows: Part I - Introduction: 1. Introduction to thin-film photovoltaics. Part II - Device characterization: 2. Fundamental electrical characterization of thin-film solar cells; 3. Electroluminescence analysis of thin-film solar modules; 4. Capacitance spectroscopy of thin-film solar cells. Part III - Materials characterization: 5. Characterizing the light trapping properties of textured surfaces with scanning near-field optical microscopy; 6. Ellipsometry; 7. Photoluminescence analysis of Si and chalcopyrite-type thin films for solar cells; 8. Steady state photocarrier grating method; 9. Time-of-flight analysis; 10. Electron Spin Resonance on Si thin films for solar cells; 11. Scanning probe microscopy on thin films for solar cells; 12. Electron microscopy on thin films for solar cells; 13. X-ray and neutron diffraction of materials for thin film solar cells; 14. Raman Spectroscopy on thin films for solar cells; 15. Soft x-ray and electron spectroscopy: a unique ''tool chest'' to characterize the chemical and electronic properties of surfaces and interfaces; 16. Elemental distribution profiling of thin films for solar cells; 17. Hydrogen effusion experiments. Part IV - Materials and device modelling: 18. Ab-initio modelling of semiconductors; 19. One-dimensional electro-optical simulations of thin film solar cells; 20. Two-dimensional electrical simulations of thin film solar cells.

  9. Polycrystalline thin-film solar cells

    International Nuclear Information System (INIS)

    A description of polycrystalline thin-film solar cells (PTFC) based on the historical development would contain the first observations by Becquerel in 1839, the research by Grondhal and Geiger on Cu20 almost one hundred years later and finally the modern story dating from 1954. In that year a single crystal Si cell and a polycrystalline cell, later recognized as a CdS/Cu2S heterojunction, both of 6% efficiency were reported. In this paper the first topic is a description of a generic solar cell; what are those materials and device features which are common to all photovoltaic systems? The special features of thin-film solar cells based on polycrystalline compound semiconductors are examined. The two materials under most active development are the II-VI compound CdTe and the I-III-VI2 chalcopyrite compound, CuInSe2, and in detail their development and prospects for the future are examined. There are some other materials which also form the basis of potential solar cells and these will be briefly reviewed. Finally, the prospects for tandem or multi-junction cells that incorporate polycrystalline semiconductors are discussed. 40 refs, 21 figs, 4 tabs

  10. Materials availability for thin film solar cells

    Science.gov (United States)

    Makita, Yunosuke

    1997-04-01

    Materials availability is one of the most important factors when we consider the mass-production of next generation photovoltaic devices. "In (indium)" is a vital element to produce high efficient thin film solar cells such as InP and CuIn(Ga)Se2 but its lifetime as a natural resource is suggested to be of order of 10˜15 years. The lifetime of a specific natural resource as an element to produce useful device substances is directly related with its abundance in the earth's crust, consumption rate and recycling rate (if recycling is economically meaningful). The chemical elements having long lifetime as a natural resource are those existing in the atmosphere such as N (nitrogen) and O (oxygen); the rich elements in the earth's crust such as Si, Ca, Sr and Ba; the mass-used metals such as Fe (iron), Al (aluminum) and Cu (copper) that reached the stage of large-scale recycling. We here propose a new paradigm of semiconductor material-science for the future generation thin film solar cells in which only abundant chemical elements are used. It is important to remark that these abundant chemical elements are normally not toxic and are fairly friendly to the environment. ?-FeSi2 is composed of two most abundant and nontoxic chemical elements. This material is one of the most promising device materials for future generation energy devices (solar cells and thermoelectric device that is most efficient at temperature range of 700-900 °C). One should remind of the versatility of ?-FeSi2 that this material can be used not only as energy devices but also as photodetector, light emitting diode and/or laser diode at the wavelength of 1.5 ?m that can be monolithically integrated on Si substrates due to the relatively small lattice mismatch.

  11. Thin-film solar cells. Past, present ... and future

    International Nuclear Information System (INIS)

    This article traces the history of thin-film solar cells from the early 1950s, to the use of photovoltaic (PV) power supplies in space missions, and finally to the present where PV is now considered as a real option for terrestrial power production and rural electrification. The development of solar cell efficiencies is described, and the development of thin-film efficiencies is compared with that of crystalline silicon wafer-based cells. The market share of thin-film solar modules, and the impact of amorphous modules on the power market are considered. Details are given of early thin-film solar cells, four decades of cadmium-telluride solar cells (1962-2001), modern materials for thin-film solar cells, cells based on amorphous silicon, thin-layer and thin-film approaches based on crystalline silicon, the use of cadmium telluride, cells based on copper-indium-selenide (CIS) and related compounds, and the dye-sensitised cell. Theoretical and technological aspects of thin-film PV are examined, and the transfer of laboratory-scale production to industrial production is explored

  12. Thin Film Solar Cells: Research in an Industrial Perspective

    OpenAIRE

    Edoff, Marika

    2012-01-01

    Electricity generation by photovoltaic conversion of sunlight is a technology in strong growth. The thin film technology is taking market share from the dominant silicon wafer technology. In this article, the market for photovoltaics is reviewed, the concept of photovoltaic solar energy conversion is discussed and more details are given about the present technological limitations of thin film solar cell technology. Special emphasis is given for solar cells which employ Cu(In,Ga)Se2 and Cu2ZnS...

  13. 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

  14. Broadband back grating design for thin film solar cells

    KAUST Repository

    Janjua, Bilal

    2013-01-01

    In this paper, design based on tapered circular grating structure was studied, to provide broadband enhancement in thin film amorphous silicon solar cells. In comparison to planar structure an absorption enhancement of ~ 7% was realized.

  15. UV imprinting for thin film solar cell application

    OpenAIRE

    Escarre, J.; Battaglia, C.; Soederstroem, K; Pahud, C.; Biron, R.; Cubero, O.; Haug, F.-J.; Ballif, C.

    2012-01-01

    UV imprinting is an interesting, low cost technique to produce large area thin film solar cells incorporating nanometric textures. Here, we review and present new results confirming that replicas of the most common textures used in photovoltaics can be obtained by UV imprinting with an excellent fidelity. The use of these replicas as substrates for amorphous and micromorph thin film silicon solar cells is also shown, together with a comparison with devices obtained on the original textures.

  16. UV imprinting for thin film solar cell application

    International Nuclear Information System (INIS)

    UV imprinting is an interesting, low cost technique to produce large area thin film solar cells incorporating nanometric textures. Here, we review and present new results confirming that replicas of the most common textures used in photovoltaics can be obtained by UV imprinting with an excellent fidelity. The use of these replicas as substrates for amorphous and micromorph thin film silicon solar cells is also shown, together with a comparison with devices obtained on the original textures

  17. Single Source Precursors for Thin Film Solar Cells

    Science.gov (United States)

    Banger, Kulbinder K.; Hollingsworth, Jennifer A.; Harris, Jerry D.; Cowen, Jonathan; Buhro, William E.; Hepp, Aloysius F.

    2002-01-01

    The development of thin film solar cells on flexible, lightweight, space-qualified substrates provides an attractive cost solution to fabricating solar arrays with high specific power, (W/kg). The use of a polycrystalline chalcopyrite absorber layer for thin film solar cells is considered as the next generation photovoltaic devices. At NASA GRC we have focused on the development of new single source precursors (SSP) and their utility to deposit the chalcopyrite semi-conducting layer (CIS) onto flexible substrates for solar cell fabrication. The syntheses and thermal modulation of SSPs via molecular engineering is described. Thin-film fabrication studies demonstrate the SSPs can be used in a spray CVD (chemical vapor deposition) process, for depositing CIS at reduced temperatures, which display good electrical properties, suitable for PV (photovoltaic) devices.

  18. Metal nanoparticles for thin film solar cells

    DEFF Research Database (Denmark)

    Gritti, Claudia

    2014-01-01

    Among the different renewable ways to produce energy, photovoltaic cells have a big potential and the research is now focusing on getting higher efficiency and at the same time saving the manufacturing costs improving the performance of thin film solar cells. The spectral distribution in the infrared wavelength region longer than 800 nm accounts for ?40% of the entire solar energy observed on Earth, and only a few solar cells can efficiently convert solar energy with such a long wavelength. The goal of this work is the harvesting of these NIR photons in order to increase the solar cells efficiency in such spectral range; after an overview of the different technologies available today, the employment of localized surface plasmons (LSPs) through the incorporation of metallic nanoparticles within the photovoltaic device is chosen as a cheap and simple method. The LSP resonance wavelength and intensity depends on the nanoparticle’s size, shape, and local dielectric environment, thus absorption enhancement in a defined wavelength range can be achieved varying these properties (tuning the LSP resonance). Even though scattering enhancement of photons above the gap of the semiconductor is useful to increase light trapping and can come along regardless, we aim, as first target, to absorb forbidden (for the semiconductor) photons by the NPs which can excite hot electrons inside the metal NP and emit them directly into the conduction band of the solar cell semiconductor, without going through the promotion of electrons from the valence band of the semiconductor. The photoemission would extend the spectral response of the photovoltaic device. Thus, NPs are placed at the metal/semiconductor interface (in order to exploit the localization characteristic of the LSP enhancement) and are used as active nanoantennas absorbing photons with energy smaller than the semiconductor gap but larger than the Schottky barrier height between metal and semiconductor. The optimization of the fabrication process of GaAs and a-Si:H Schottky solar cells is first conducted and subsequently, the incorporation of Au or Ag nanoparticles at the interface between the semiconductor and a transparent conductive oxide layer (TCO), used to complete the Schottky junction and as top electrode, has followed. A model representing the device structure with GaAs, ITO and incorporated Au disks or Ag ellipsoids in between, is developed and used for FTDT simulations, in order to identify the set of parameters (NPs size and array periodicity) which could show LSP resonance in the NIR range. Two techniques are here used to fabricate NPs: electron beam lithography (EBL), to deposit ordered arrays of gold and silver NPs, simple to be compared with modelling; and electroless plating, to grow silver nanocrystals with a cheap technology, producing random distribution of particles. These techniques are studied and optimized aiming to obtain NPs patterns of different size, periodicity and density on the substrates required for the incorporation within the solar cell structure (GaAs, SiO2, Si3N4, AZO/Cr), in order to investigate the LSP resonance and tune it to exploit it below the energy band gap of the semiconductor. EBL is a difficult technique when working by lift-off on critical size (20-50 nm) nanoparticles. The optimization of the process saw a change from ZEP resist to double layer of PMMA and always requires preliminary exposure dose-tests and final particular attention for lift-off step. EBL resulted to be more suitable for silver NPs, since the deposition of gold (on top of an adhesion thin titanium layer) leads to a variation and non-regularity in the shape of the NPs: truncated cones with varying bottom and top radius. The difference in shape causes broadening of the resonance peak (as dimostrated by simulations). Electroless plating is a technique, based on chemical reactions, which makes use, in the process chosen for this work, of AgNO3 powder, diluted in water, and HF at very low concentrations. This kind of deposition is very cheap but precise optimization of r

  19. Light trapping in thin film organic solar cells

    Directory of Open Access Journals (Sweden)

    Zheng Tang

    2014-10-01

    Full Text Available A major issue in organic solar cells is the poor mobility and recombination of the photogenerated charge carriers. The active layer has to be kept thin to facilitate charge transport and minimize recombination losses. However, optical losses due to inefficient light absorption in the thin active layers can be considerable in organic solar cells. Therefore, light trapping schemes are critically important for efficient organic solar cells. Traditional light trapping schemes for thick solar cells need to be modified for organic thin film solar cells in which coherent optics and wave effects play a significant role. In this review, we discuss the light trapping schemes for organic thin film solar cells, which includes geometric engineering of the structure of the solar cell at the micro and nanoscale, plasmonic structures, and more.

  20. Development of A Thin Film Crystalline Silicon Solar Cell

    International Nuclear Information System (INIS)

    A new design for a single junction, thin film Si solar cell is presented. The cell design is compatible with low-temperature processing required for the use of a low-cost glass substrate, and includes effective light trapping and impurity gettering. Elements of essential process steps are discussed

  1. Thin Film Solar Cells and their Optical Properties

    Directory of Open Access Journals (Sweden)

    Stanislav Jurecka

    2006-01-01

    Full Text Available In this work we report on the optical parameters of the semiconductor thin film for solar cell applications determination. The method is based on the dynamical modeling of the spectral reflectance function combined with the stochastic optimization of the initial reflectance model estimation. The spectral dependency of the thin film optical parameters computations is based on the optical transitions modeling. The combination of the dynamical modeling and the stochastic optimization of the initial theoretical model estimation enable comfortable analysis of the spectral dependencies of the optical parameters and incorporation of the microstructure effects on the solar cell properties. The results of the optical parameters ofthe i-a-Si thin film determination are presented.

  2. Thin-film crystalline silicon solar cells

    CERN Document Server

    Brendel, Rolf

    2011-01-01

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

  3. Thin-film silicon solar cell technology.

    Czech Academy of Sciences Publication Activity Database

    Shah, A. V.; Schade, H.; Van??ek, Milan; Meier, J.; Vallat-Sauvain, E.; Wyrsch, N.; Kroll, U.; Droz, C.; Bailat, J.

    2004-01-01

    Ro?. 12, - (2004), s. 113-142. ISSN 1062-7995 R&D Projects: GA MŽP SN/320/11/03 Institutional research plan: CEZ:AV0Z1010914 Keywords : thin-film silicon modules * hydrogenerated amorphous silicon(a-Si:H) * hydrogenerated microcrystalline (?c-Si:H) * transparent conductive oxydes(TCOs) * building-integrated photovoltaics( BIPV ) Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.196, year: 2004

  4. Buried contact multijunction thin film silicon solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Green, M. [Univ. of New South Wales, Sydney (Australia)

    1995-08-01

    In early 1994, the Center for Photovoltaic Devices and Systems announced the filing of patent applications on an improved silicon thin film photovoltaic module approach. With material costs estimated to be about 20 times lower than those in present silicon solar cell modules along with other production advantages, this technology appears likely to make low cost, high performance solar modules available for the first time. This paper describes steps involved in making a module and module performance.

  5. 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.

  6. Grain boundary assisted photocurrent collection in thin film solar cells

    Directory of Open Access Journals (Sweden)

    Harndt Susanna

    2015-01-01

    Full Text Available The influence of absorber grain boundaries on the photocurrent transport in chalcopyrite based thin film solar cells has been calculated using a two dimensional numerical model. Considering extreme cases, the variation in red response is more expressed than in one dimensional models. These findings may offer an explanation for the strong influence of buffer layer preparation on the spectral response of cells with small grained absorbers.

  7. Grain boundary assisted photocurrent collection in thin film solar cells

    Science.gov (United States)

    Harndt, Susanna; Kaufmann, Christian A.; Lux-Steiner, Martha C.; Klenk, Reiner; Nürnberg, Reiner

    2015-06-01

    The influence of absorber grain boundaries on the photocurrent transport in chalcopyrite based thin film solar cells has been calculated using a two dimensional numerical model. Considering extreme cases, the variation in red response is more expressed than in one dimensional models. These findings may offer an explanation for the strong influence of buffer layer preparation on the spectral response of cells with small grained absorbers.

  8. Crystalline silicon thin-film solar cells on ceramic substrates

    Science.gov (United States)

    Rehman, Atteq Ur; Lee, Sang Hee; Lee, Soo Hong

    2015-03-01

    We provide a review and analysis of research on crystalline silicon thin-film solar cells (CSiTFSCs) on ceramic substrates. The use of foreign substrates (non-silicon materials) for the processing of crystalline silicon solar cells could potentially decrease solar-grade silicon consumption and significantly reduce module costs. In order to enhance the efficiency potential of CSiTFSCs on ceramic substrates, high-temperature silicon film deposition is favored. High-quality electronic-grade silicon films are intended to be deposited at higher temperature as it can help increase both deposition rates and grain sizes. The potential low-cost ceramic substrates have some major restrictions in terms of cell processing technology at high temperatures. In this paper, an overview of the research on thin-film solar-cell technologies on ceramic substrates is presented. Major processing steps for CSiTFSC such as substrate/intermediate layer requirements and silicon thin-film deposition at high temperatures will be discussed. So far, devices have been demonstrated with efficiencies up to 13.4% on graphite, 8.2% on mullite, and 9.4% on silicon nitride (Si3N4) ceramic substrates. [Figure not available: see fulltext.

  9. Microcrystalline organic thin-film solar cells.

    Science.gov (United States)

    Verreet, Bregt; Heremans, Paul; Stesmans, Andre; Rand, Barry P

    2013-10-11

    Microcrystalline organic films with tunable thickness are produced directly on an indium-tin-oxide substrate, by crystallizing a thin amorphous rubrene film followed by its use as a template for subsequent homoepitaxial growth. These films, with exciton diffusion lengths exceeding 200 nm, produce solar cells with increasing photocurrents at thicknesses up to 400 nm with a fill factor >65%, demonstrating significant potential for microcrystalline organic electronic devices. PMID:23939936

  10. Thin film cadmium telluride solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Chu, T.L.; Chu, S.S.; Xi, X.J.; Yang, Y.T.

    1983-05-01

    Cadmium telluride films have been deposited on coated graphite and mullite substrates by the direct combination of the vapors of the elements in a hydrogen atmosphere. The properties of nearly stoichiometric films on mullite substrates were measured by the van der Pauw technique in the temperature range of 25/sup 0/ - 150/sup 0/C. The deposition of n-type cadmium telluride by using hydrogen iodide as a dopant and the deposition of p-type cadmium telluride films by using arsine or phosphine as a dopant were studied. Schottky barrier solar cells were prepared from n-type cadmium telluride films and heterojunction cells from p-type cadmium telluride films.

  11. Thin film polycrystalline silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, A. K.; Feng, T.; Eustace, D. J.; Maruska, H. P.

    1980-01-01

    During the present quarter efficiency of heterostructure solar cells has been increased from 13 to 13.7% for single crystal and from 10.3 to 11.2% for polysilicon. For polysilicon the improvements can be attributed to reductions in grid-area coverage and in reflection losses and for single crystal to a combination of reduction in grid-area coverage and increase in fill factor. The heterostructure cells in both cases were IT0/n-Si solar cells. Degradation in Sn0/sub 2//n-Si solar cells can be greatly reduced to negligible proportions by proper encapsulation. The cells used in stability tests have an average initial efficiency of 11% which reduces to a value of about 10.5% after 6 months of exposure to sunlight and ambient conditions. This small degradation occurs within the first month, and the efficiency remains constant subsequently. The reduction in efficiency is due to a decrease in the open-circuit voltage only, while the short-circuit current and fill factor remain constant. The effects of grain-size on the Hall measurements in polysilicon have been analyzed and interpreted, with some modifications, using a model proposed by Bube. This modified model predicts that the measured effective Hall voltage is composed of components originating from the bulk and space-charge region. For materials with large grains, the carrier concentration is independent of the inter-grain boundary barrier, whereas the mobility is dependent on it. However, for small rains, both the carrier density and mobility depend on the barrier. These predictions are consistant with experimental results of mm-size Wacker polysilicon and ..mu..m-size NTD polysilicon.

  12. Method for producing thin-film multilayer solar cells

    OpenAIRE

    Rampino, Stefano; Gilioli, Edmondo; Bissoli, Francesco; Pattini, Francesco

    2010-01-01

    Description: A method for manufacturing high-quality thin film solar cells entirely by the Pulsed Electron Deposition (PED) is presented. The solar cell is a multi-layer architecture composed with an absorber layer with a chalcopyrite structure and the general composition Cu (In, Ga, Al) (Se, S)2 or CIGASS, deposited on a metallic substrate, that is the lower electrical contact or "back contact", by one or more buffer layer(s) and a layer acting as an electrical contact or the higher "top con...

  13. Thin film solar cells from earth abundant materials growth and characterization of Cu2(ZnSn)(SSe)4 thin films and their solar cells

    CERN Document Server

    Kodigala, Subba Ramaiah

    2013-01-01

    The fundamental concept of the book is to explain how to make thin film solar cells from the abundant solar energy materials by low cost. The proper and optimized growth conditions are very essential while sandwiching thin films to make solar cell otherwise secondary phases play a role to undermine the working function of solar cells. The book illustrates growth and characterization of Cu2ZnSn(S1-xSex)4 thin film absorbers and their solar cells. The fabrication process of absorber layers by either vacuum or non-vacuum process is readily elaborated in the book, which helps for further developm

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

    Science.gov (United States)

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

    2011-08-09

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

  15. Process for fabricating thin film photovoltaic solar cells

    International Nuclear Information System (INIS)

    This patent describes a method of fabricating thin film photovoltaic solar cells made by sequentially forming a first contact layer on a substrate, a first semiconductor layer, and a second semiconductor layer, and a second contact layer. At least one of the contact layers is transparent and at least one of the semiconductor layers comprises a tellurium containing II-VI compound the improvement being the steps of heat treating the cell after the second contact layer has been formed, and then rapidly cooling the cell at a temperature reduction rate of at least 100C per second

  16. New 3-dimensional nanostructured thin film silicon solar cells.

    Czech Academy of Sciences Publication Activity Database

    Van??ek, Milan; Neykova, Neda; Babchenko, Oleg; Purkrt, Adam; Poruba, Aleš; Remeš, Zden?k; Holovský, Jakub; Hruška, Karel; Meier, J.; Kroll, U.

    München : WIP-Renewable energies, 2010, s. 2763-2766. ISBN 3-936338-26-4. [European Photovoltaic Solar Energy Conference /25./ and World Conference on Photovoltaic Energy Conversion /5./. Valencia (ES), 06.09.2010-10.09.2010] R&D Projects: GA MŠk(CZ) 7E09057 Grant ostatní: EU FP7 N2P(XE) CP-IP 214134-2 Institutional research plan: CEZ:AV0Z10100521 Keywords : thin film solar cells, * TCO transparent conductive oxides * a-Si * high stable efficiency, * ZnO Subject RIV: BM - Solid Matter Physics ; Magnetism

  17. Development of CIGS2 thin film solar cells

    International Nuclear Information System (INIS)

    Research and development of CuIn1-xGa xSe2-yS y (CIGSS) thin-film solar cells on ultralightweight flexible metallic foil substrates is being carried out at FSEC PV Materials Lab for space applications. Earlier, the substrate size was limited to 3 cm x 2.5 cm. Large-area sputtering systems and scrubber for hydrogen selenide and sulfide have been designed and constructed for preparation of CIGSS thin-films on large (15 cm x 10 cm) substrates. A selenization/sulfurization furnace donated by Shell (formerly Siemens) Solar has also been refurbished and upgraded. The sputtering target assembly design was modified for proper clamping of targets and effective cooling. A new design of the magnetic assembly for large-area magnetron sputtering sources was implemented so as to achieve uniform deposition on large area. Lightweight stainless steel foil and ultralightweight titanium foil substrates were utilized to increase the specific power of solar cells. Sol-gel derived SiO2 layers were coated on titanium foil by dip coating method. Deposition parameters for the preparation of molybdenum back contact layers were optimized so as to minimize the residual stress as well as reaction with H2S. Presently large (15 cm x 10 cm) CuIn1-xGa xS2 (CIGS2) thin film solar cells are being prepared on Mo-coated titanium and stainless steel foil by sulfurization of CuGa/In metallic precursors in diluted Ar:H2S(4%). Heterojunction partner CdS layers are deposited by chemical bath deposition. The regeneration sequence of ZnO/ZnO:Al targets was optimized for obtaining consistently good-quality, transparent and conducting ZnO/ZnO:Al bilayer by RF magnetron-sputter deposition. Excellent facilities at FSEC PV Materials Lab are one of its kinds and could serve as a nucleus of a small pilot plant for CIGSS thin film solar cell fabrication

  18. Polycrystalline silicon thin-film solar cells on glass

    Energy Technology Data Exchange (ETDEWEB)

    Gall, S.; Becker, C.; Conrad, E.; Dogan, P.; Fenske, F.; Gorka, B.; Lee, K.Y.; Rau, B.; Ruske, F.; Rech, B. [Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH (formerly Hahn-Meitner-Institut Berlin GmbH), Department Silicon Photovoltaics (SE1), Kekulestr. 5, D-12489 Berlin (Germany)

    2009-06-15

    Poly-Si thin-film solar cells on glass feature the potential to reach single-junction efficiencies of 15% or even higher at low costs. In this paper innovative approaches are discussed, which could lead to substantial efficiency improvements and significant cost reductions: (i) preparation of large-grained poly-Si films using the 'seed layer concept' targeting at high material quality, (ii) utilization of ZnO:Al-coated glass enabling simple contacting and light-trapping schemes, (iii) utilization of high-rate electron-beam evaporation for the absorber deposition offering a high potential for cost reduction. (author)

  19. Thin-film intermediate band chalcopyrite solar cells

    International Nuclear Information System (INIS)

    Chalcopyrite-based solar cells currently lead the efficiency tables of thin-film photovoltaic technologies. Further improvements are foreseen upon implementation of an intermediate band in the absorber layers. We present a theoretical analysis of the efficiency limit for this type of device as a function of factors such as the gap of the host, the relative position of the intermediate band with respect to the band edge and the level of light concentration used as illumination. We have also considered the impact of non-idealities on the performance of the device, particularly the effect of electronic losses related to non-radiative recombination

  20. Optimization of photonics for corrugated thin-film solar cells

    Science.gov (United States)

    Deparis, Olivier; Vigneron, Jean Pol; Agustsson, Otto; Decroupet, Daniel

    2009-11-01

    The amount of solar energy reaching the active (photovoltaic) layer in a thin-film solar cell can be increased by reducing the Fresnel reflection losses at the interfaces. By using corrugated interfaces (at the wavelength scale), adiabatic propagation of the electromagnetic radiation is achieved over a broad wavelength range throughout the structure, which leads to an increase in the light that is absorbed in the active layer and, ultimately, to the improvement of the photovoltaic conversion efficiency. In this article, we have considered the case of corrugated thin-film solar cell structures and we have studied theoretically the optimization of such structures from the point of view of photonics. The focus was put on periodic pyramidal interface corrugations because they were similar to those existing at the surface of corrugated transparent electrodes on which active layers can be deposited. Because of their technological importance, we chose to work with fluorine-doped tin oxide as front electrode material and with amorphous silicon as active material. Using an original three dimensional transfer matrix method, we solved the electromagnetic wave propagation problem in the general case of laterally periodic stratified media and we compared this solution with effective medium approximated solution. On the basis of typical pyramid sizes, we demonstrated, through numerical simulations, the optimization of the global light energy intake by means of corrugations of increasing complexity. The best structures were found to be based on pyramid arrays having subwavelength periods and aspect ratio values close to one. Typically, a pyramidal structure with base and height both equal to 300 nm led to a global energy intake equal to I =0.98 (integrated over the spectral range 400-710 nm), which represented a 24% improvement in comparison with the global energy intake of a planar structure (I =0.79).

  1. Cuinse2 Thin Film For Solar Cell By Flash Evaporation

    Directory of Open Access Journals (Sweden)

    A.H. Soepardjo

    2009-11-01

    Full Text Available Deposition of thin films for material solar cell CuInSe2 are relatively simple. In this research mainly focused on the use of flash evaporation method, and the material created can then be characterized by optical and electrical properties. The optical characterization is done by X-ray Diffraction (XRD, Energy Dispersive Spectroscopy (EDS, and transmission and reflection by UV-VIS spectrophotometry. Electrical characterization is done by utilizing the Hall effect equipment. From these characterization, the atomic structure, absorption coefficient, energy gap, material type, composition of each elements and the mobility of CuInSe2 can be measured and determined. During process evaporation were carried out at substrate temperatures the range between 20ºC-415ºC.

  2. Study of back reflectors for thin film silicon solar cells

    International Nuclear Information System (INIS)

    In this study, the reflection properties of transparent conductive oxide (TCO) films i.e. aluminum doped zinc oxide (ZnO:Al) and boron doped zinc oxide (ZnO:B) films plus aluminum (Al) films or white polyvinyl butyral (PVB) foils, which are usually used as the combined back reflectors of thin film silicon solar cells, are investigated. Sputtered ZnO:Al films were etched in diluted hydrochloric acid (1%) to achieve rough surface structures while textured ZnO:B films were directly prepared by a low pressure chemical vapor deposition technique. It is found that the rough TCO/Al reflectors show a low total reflection, which is mainly due to the parasitic absorption by the surface plasmons at the rough TCO/Al interfaces as well as the absorption in the TCO films. Differently, the rough TCO/white PVB foil reflectors display a slightly high light reflection regardless of the influence of the rough interface without the excitation of surface plasmons. Thus, the TCO/white PVB foil back reflectors could be a good candidate with respect to light utilization when they are applied in thin film silicon solar cells. - Highlights: • White polyvinyl butyral and transparent conductive oxide materials are used. • The reflection properties of TCO/Al and TCO/white PVB foil reflectors are studied. • The ZnO:Al and ZnO:B films are used as two types of TCO materials. • TCO/white PVB foil reflector shows a high reflection compared to TCO/Al reflector

  3. Study of back reflectors for thin film silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, H.; Mai, Y. [Baoding Tianwei Solarfilms Co., Ltd., Baoding 071051 (China); Wan, M. [Department of Chemistry and Material Science, Hunan Institute of Humanities, Science and Technology, Loudi 417000 (China); Gao, J.; Wang, Y.; He, T.; Feng, Y.; Yin, J.; Du, J.; Wang, J.; Sun, R. [Baoding Tianwei Solarfilms Co., Ltd., Baoding 071051 (China); Huang, Y., E-mail: y.huang@btw-solarfilms.com [Baoding Tianwei Solarfilms Co., Ltd., Baoding 071051 (China)

    2013-07-31

    In this study, the reflection properties of transparent conductive oxide (TCO) films i.e. aluminum doped zinc oxide (ZnO:Al) and boron doped zinc oxide (ZnO:B) films plus aluminum (Al) films or white polyvinyl butyral (PVB) foils, which are usually used as the combined back reflectors of thin film silicon solar cells, are investigated. Sputtered ZnO:Al films were etched in diluted hydrochloric acid (1%) to achieve rough surface structures while textured ZnO:B films were directly prepared by a low pressure chemical vapor deposition technique. It is found that the rough TCO/Al reflectors show a low total reflection, which is mainly due to the parasitic absorption by the surface plasmons at the rough TCO/Al interfaces as well as the absorption in the TCO films. Differently, the rough TCO/white PVB foil reflectors display a slightly high light reflection regardless of the influence of the rough interface without the excitation of surface plasmons. Thus, the TCO/white PVB foil back reflectors could be a good candidate with respect to light utilization when they are applied in thin film silicon solar cells. - Highlights: • White polyvinyl butyral and transparent conductive oxide materials are used. • The reflection properties of TCO/Al and TCO/white PVB foil reflectors are studied. • The ZnO:Al and ZnO:B films are used as two types of TCO materials. • TCO/white PVB foil reflector shows a high reflection compared to TCO/Al reflector.

  4. Utility of Thin-Film Solar Cells on Flexible Substrates for Space Power

    Science.gov (United States)

    Dickman, J. E.; Hepp, A. F.; Morel, D. L.; Ferekides, C. S.; Tuttle, J. R.; Hoffman, D. J.; Dhere, N. G.

    2004-01-01

    The thin-film solar cell program at NASA GRC is developing solar cell technologies for space applications which address two critical metrics: specific power (power per unit mass) and launch stowed volume. To be competitive for many space applications, an array using thin film solar cells must significantly increase specific power while reducing stowed volume when compared to the present baseline technology utilizing crystalline solar cells. The NASA GRC program is developing two approaches. Since the vast majority of the mass of a thin film solar cell is in the substrate, a thin film solar cell on a very lightweight flexible substrate (polymer or metal films) is being developed as the first approach. The second approach is the development of multijunction thin film solar cells. Total cell efficiency can be increased by stacking multiple cells having bandgaps tuned to convert the spectrum passing through the upper cells to the lower cells. Once developed, the two approaches will be merged to yield a multijunction, thin film solar cell on a very lightweight, flexible substrate. The ultimate utility of such solar cells in space require the development of monolithic interconnections, lightweight array structures, and ultra-lightweight support and deployment techniques.

  5. Lateral matching of periodic front and back textures in thin film silicon solar cells

    Science.gov (United States)

    Gao, Fei; Wang, Haoshi; Gao, Yuqiao; Wu, Yi; Liu, Shengzhong (Frank); Zhou, Songjie; Li, Fuxian; Zheng, Xiaoyao; Wu, Huijun; Liu, Tingzhuo

    2015-12-01

    We systematically study the influence of the relative lateral position of the front and back periodic textures on the light absorption in microcrystalline Si thin film solar cells by finite difference time domain method. We show that there is an optimum lateral position match between the periodic front and back textures, which allows maximum light absorption to be obtained in the Si thin film solar cells. A relative lateral shift between the front and back periodic textures breaks the symmetry of the conformal cell structure, which can result in more wave modes in the Si thin film solar cells.

  6. Charge carrier dynamics in thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Strothkaemper, Christian

    2013-06-24

    This work investigates the charge carrier dynamics in three different technological approaches within the class of thin film solar cells: radial heterojunctions, the dye solar cell, and microcrystalline CuInSe{sub 2}, focusing on charge transport and separation at the electrode, and the relaxation of photogenerated charge carriers due to recombination and energy dissipation to the phonon system. This work relies mostly on optical-pump terahertz-probe (OPTP) spectroscopy, followed by transient absorption (TA) and two-photon photoemission (2PPE). The charge separation in ZnO-electrode/In{sub 2}S{sub 3}-absorber core/shell nanorods, which represent a model system of a radial heterojunction, is analyzed by OPTP. It is concluded, that the dynamics in the absorber are determined by multiple trapping, which leads to a dispersive charge transport to the electrode that lasts over hundreds of picoseconds. The high trap density on the order of 10{sup 19}/cm{sup 3} is detrimental for the injection yield, which exhibits a decrease with increasing shell thickness. The heterogeneous electron transfer from a series of model dyes into ZnO proceeds on a time-scale of 200 fs. However, the photoconductivity builds up just on a 2-10 ps timescale, and 2PPE reveals that injected electrons are meanwhile localized spatially and energetically at the interface. It is concluded that the injection proceeds through adsorbate induced interface states. This is an important result because the back reaction from long lived interface states can be expected to be much faster than from bulk states. While the charge transport in stoichiometric CuInSe{sub 2} thin films is indicative of free charge carriers, CuInSe{sub 2} with a solar cell grade composition (Cu-poor) exhibits signs of carrier localization. This detrimental effect is attributed to a high density of charged defects and a high degree of compensation, which together create a spatially fluctuating potential that inhibits charge transport. On the other hand, the charge carrier lifetime in Cu-poor CIS is orders of magnitude higher as in stoichiometric CIS. This is explained by assuming that the CuIn antisite is the most effective recombination center.

  7. Photovoltaic solar cell from low-cost thin-film technology

    International Nuclear Information System (INIS)

    Full text : One of the main hindrances of using solar energy for electrical power supply is the high initial cost. Thin-film technologies hold considerable promise for substantial cost reduction for photovoltaic solar cells. The paper reviews the present state of the most advanced thin-film technologies. Amorphous silicon solar cells have surmounted the barrier to mass production. Pilot manufacturing lines are under construcion for CdTe thin-film module. Cu(In, Ga)Se2 has reached a record efficiency of 18.8 percent in the laboratory and pilot productions have benn announced by various companies

  8. Photovoltaic solar cell from low-cost thin-film technology

    International Nuclear Information System (INIS)

    Full text : One of the main hindrances of using solar energy for electrical power supply is the high initial cost. Thin-film technologies hold considerable promise for substantial cost reduction for photovoltaic solar cells. The paper reviews the present state of the most advanced thin-film technologies. Amorphous silicon (a-Si:H) solar cells have surmounted the barrier to mass production. Pilot manufacturing lines are under construction for CdTe thin-film module. Cu(In,Ga)Se2 has reached a record efficiency of 18.8% in the laboratory and pilot productions have been announced by various companies

  9. Optical modeling of thin film silicon solar cells with random and periodic light management textures

    OpenAIRE

    Lockau, Daniel

    2013-01-01

    Better light trapping concepts are a prerequisite for the success of silicon thin film photovoltaics. This thesis presents optical simulations of silicon thin film solar cells with statistical and periodic absorption enhancing textures. For simulation of statistically textured solar cells a rough surface synthesization method is characterized and found applicable for generation of the morphology of commercial fluorine doped tin oxide surfaces. The extended rough interface scatterer is modeled...

  10. Surface Engineering of ZnO Thin Film for High Efficiency Planar Perovskite Solar Cells

    Science.gov (United States)

    Tseng, Zong-Liang; Chiang, Chien-Hung; Wu, Chun-Guey

    2015-09-01

    Sputtering made ZnO thin film was used as an electron-transport layer in a regular planar perovskite solar cell based on high quality CH3NH3PbI3 absorber prepared with a two-step spin-coating. An efficiency up to 15.9% under AM 1.5G irradiation is achieved for the cell based on ZnO film fabricated under Ar working gas. The atmosphere of the sputtering chamber can tune the surface electronic properties (band structure) of the resulting ZnO thin film and therefore the photovoltaic performance of the corresponding perovskite solar cell. Precise surface engineering of ZnO thin film was found to be one of the key steps to fabricate ZnO based regular planar perovskite solar cell with high power conversion efficiency. Sputtering method is proved to be one of the excellent techniques to prepare ZnO thin film with controllable properties.

  11. Advances in thin-film solar cells for lightweight space photovoltaic power

    Science.gov (United States)

    Landis, Geoffrey A.; Bailey, Sheila G.; Flood, Dennis J.

    1989-01-01

    The present stature and current research directions of photovoltaic arrays as primary power systems for space are reviewed. There have recently been great advances in the technology of thin-film solar cells for terrestrial applications. In a thin-film solar cell the thickness of the active element is only a few microns; transfer of this technology to space arrays could result in ultralow-weight solar arrays with potentially large gains in specific power. Recent advances in thin-film solar cells are reviewed, including polycrystalline copper-indium selenide (CuInSe2) and related I-III-VI2 compounds, polycrystalline cadmium telluride and related II-VI compounds, and amorphous silicon:hydrogen and alloys. The best experimental efficiency on thin-film solar cells to date is 12 percent AMO for CuIn Se2. This efficiency is likely to be increased in the next few years. The radiation tolerance of thin-film materials is far greater than that of single-crystal materials. CuIn Se2 shows no degradation when exposed to 1 MeV electrons. Experimental evidence also suggests that most of all of the radiation damage on thin-films can be removed by a low temperature anneal. The possibility of thin-film multibandgap cascade solar cells is discussed, including the tradeoffs between monolithic and mechanically stacked cells. The best current efficiency for a cascade is 12.5 percent AMO for an amorphous silicon on CuInSe2 multibandgap combination. Higher efficiencies are expected in the future. For several missions, including solar-electric propulsion, a manned Mars mission, and lunar exploration and manufacturing, thin-film photovolatic arrays may be a mission-enabling technology.

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

    Directory of Open Access Journals (Sweden)

    J.R. Ray

    2011-01-01

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

  13. Preparation of vanadium diselenide thin films and their application in CdTe solar cells

    International Nuclear Information System (INIS)

    Vanadium diselenide thin films were prepared by electron beam evaporation. The properties of vanadium diselenide thin films were investigated using X-ray diffraction, scanning electron microscope, transmission spectra, electrical and Hall measurements. To further investigate the application of vanadium diselenide thin films, device performance in CdTe solar cells with a vanadium diselenide layer was also studied. The results indicate that vanadium diselenide thin films had a stable hexagonal structure after annealing. The thin films were p-type semiconductor materials with the high work function and high carrier concentration. Vanadium diselenide thin films could form a good ohmic contact to CdTe solar cells. Thus, cell performance was greatly improved when introduced a vanadium diselenide buffer layer. - Highlights: • VSe2 was prepared by electron beam evaporation. • VSe2 was a p-type material with the high work function and high carrier concentration. • VSe2 was used as a Cu-free buffer layer in CdTe solar cells. • Performance of CdTe solar cells was improved

  14. Crystalline silicon thin film growth by ECR plasma CVD for solar cells

    International Nuclear Information System (INIS)

    This thesis describes the background, motivation and work carried out towards this PhD programme entitled 'Crystalline Silicon Thin Film Growth by ECR Plasma CVD for Solar Cells'. The fundamental principles of silicon solar cells are introduced with a review of silicon thin film and bulk solar cells. The development and prospects for thin film silicon solar cells are described. Some results of a modelling study on thin film single crystalline solar cells are given which has been carried out using a commercially available solar cell simulation package (PC-1D). This is followed by a description of thin film deposition techniques. These include Chemical Vapour Deposition (CVD) and Plasma-Assisted CVD (PACVD). The basic theory and technology of the emerging technique of Electron Cyclotron Resonance (ECR) PACVD, which was used in this research, are introduced and the potential advantages summarised. Some of the basic methods of material and cell characterisation are briefly described, together with the work carried out in this research. The growth by ECR PACVD at temperatures 2 illumination. The best efficiency in the ECR grown structures was 13.76% using an epitaxial emitter. Cell performance was analysed in detail and the factors controlling performance identified by fitting self-consistently the fight and dark current-voltage and spectral response data using PC-1D. Finally, the conclusions for this research and suggestions for further work are outlined. (author)

  15. Hydrogen passivation of polycrystalline Si thin film solar cells

    International Nuclear Information System (INIS)

    Hydrogen passivation is a key process step in the fabrication of polycrystalline Si (poly-Si) thin film solar cells. In this work a parallel plate rf plasma setup was used for the hydrogen passivation treatment. The main topics that have been investigated are (i) the role of plasma parameters (like hydrogen pressure, electrode gap and plasma power), (ii) the dynamics of the hydrogen treatment and (iii) passivation of poly-Si with different material properties. Passivation was characterized by measuring the open-circuit voltage VOC of poly-Si reference samples. Optimum passivation conditions were found by measurements of the breakdown voltage Vbrk of the plasma for different pressures p and electrode gaps d. For each pressure, the best passivation was achieved at a gap d that corresponded to the minimum in Vbrk. Plasma simulations were carried out, which indicate that best VOC corresponds to a minimum in ion energy. VOC was not improved by a larger H flux. Investigations of the passivation dynamic showed that a plasma treatment in the lower temperature range (?400 C) is slow and takes several hours for the VOC to saturate. Fast passivation can be successfully achieved at elevated temperatures around 500 C to 600 C with a plateau time of 10 min. It was found that prolonged hydrogenation leads to a loss in VOC, which is less pronounced within the observed optimum temperature range (500 C-600 C). Electron beam evaporation has been investigated as an alternative method to fabricate poly-Si absorbers. The material properties have been tuned by alteration of substrate temperature Tdep=200-700 C and were characterized by Raman, ESR and VOC measurements. Largest grains were obtained after solid phase crystallization (SPC) of a-Si, deposited in the temperature range of 300 C. The defect concentration of Si dangling bonds was lowered by passivation by about one order of magnitude. The lowest dangling bond concentration of 2.5.1016 cm-3 after passivation was found for poly-Si with largest grains and coincides with best solar cell results, obtained after rapid thermal annealing and hydrogen passivation. Hydrogen passivation of poly-Si films was successfully achieved with a parallel plate rf H plasma treatment at elevated temperatures around 500 C to 600 C. Yet it seems that treatment induced defect generation causes a loss in VOC with prolonged passivation time and should be minimized. In order to achieve high open circuit voltages larger than 450 mV, in addition to hydrogen passivation, low recombination at the interfaces becomes more and more important. (orig.)

  16. High power impulse magnetron sputtering of CIGS thin films for high efficiency thin film solar cells.

    Czech Academy of Sciences Publication Activity Database

    Olejní?ek, Ji?í; Hubi?ka, Zden?k; Kohout, Michal; Kšírová, Petra; Kment, Št?pán; Brunclíková, Michaela; ?ada, Martin; Darveau, S.A.; Exstrom, C.L.

    2014-01-01

    Ro?. 1, ?. 3 (2014), s. 135-137. ISSN 2336-2626 R&D Projects: GA MŠk LH12045 Institutional support: RVO:68378271 Keywords : CIGS * HiPIMS * emission spectroscopy * thin films * magnetron sputtering Subject RIV: BL - Plasma and Gas Discharge Physics http://fyzika.feld.cvut.cz/misc/ppt/articles/2014/olejnicek.pdf

  17. Enhanced Efficiency of Light-Trapping Nanoantenna Arrays for Thin Film Solar Cells

    CERN Document Server

    Simovski, Constantin R; Voroshilov, Pavel M; Guzhva, Michael E; Belov, Pavel A; Kivshar, Yuri S

    2013-01-01

    We suggest a novel concept of efficient light-trapping structures for thin-film solar cells based on arrays of planar nanoantennas operating far from plasmonic resonances. The operation principle of our structures relies on the excitation of chessboard-like collective modes of the nanoantenna arrays with the field localized between the neighboring metal elements. We demonstrated theoretically substantial enhancement of solar-cell short-circuit current by the designed light-trapping structure in the whole spectrum range of the solar-cell operation compared to conventional structures employing anti-reflecting coating. Our approach provides a general background for a design of different types of efficient broadband light-trapping structures for thin-film solar-cell technologically compatible with large-area thin-film fabrication techniques.

  18. Light trapping with plasmonic back contacts in thin-film silicon solar cells

    OpenAIRE

    Paetzold, Ulrich Wilhelm

    2012-01-01

    Trapping light in silicon solar cells is essential as it allows an increase in the absorption of incident sunlight in optically thin silicon absorber layers. This way, the costs of the solar cells can be reduced by lowering the material consumption and decreasing the physical constraints on the material quality. In this work, plasmonic light trapping with Ag back contacts in thin-film silicon solar cells is studied. Solar cell prototypes with plasmonic back contacts are presented along with o...

  19. Study on AlxNiy Alloys as Diffusion Barriers in Flexible Thin Film Solar Cells

    International Nuclear Information System (INIS)

    Co-sputtered AlxNiy thin films were used as diffusion barriers between aluminum and hydrogenated microcrystalline silicon (?c-Si:H) for flexible thin film solar cells. The stoichiometric ratio of AlxNiy showed a significant effect on the structures of the films. The obtained Al3Ni2 film was amorphous, while polycrystalline films were obtained when the ratio of aluminum to nickel was 1:1 and 2:3. An auger electron spectroscope and four-point probe system were applied to test the resistance to the interdiffusion between aluminum and silicon, as well as the conductivities of the AlxNiy barriers. The data of auger depth profile showed that the content of silicon was the minimum in the aluminum layer after sputtering for 4 min using AlNi thin film as the barrier layer. Compared to other AlxNiy alloys, the AlNi thin film possessed the lowest sheet resistance.

  20. Optical absorption losses in metal layers used in thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Remes, Zdenek; Holovsky, Jakub; Purkrt, Adam; Izak, Tibor; Poruba, Ales; Vanecek, Milan [Institute of Physics, Academy of Sciences of the Czech Republic, v.v.i., Cukrovarnicka 10, 16253 Prague (Czech Republic); Dagkaldiran, Uemit [IEF5-Photovoltaik, Forschungszentrum Juelich GmbH, 52425 Juelich (Germany); Yates, Heather M.; Evans, Philip; Sheel, David W. [Institute for Materials Research, University of Salford, Manchester, M5 4WT (United Kingdom)

    2010-09-15

    We apply optical transmittance and reflectance spectroscopy, photothermal deflection spectroscopy (PDS) and laser calorimetry (LC) to evaluate optical absorption losses at rough interface between thin conductive oxide (TCO) and metal films used as backreflectors and electrical contacts in thin film solar cells. The paper proposes a simple method how to model the dielectric function of rough metal layers used in thin film solar cells. We show that the rough metal layer optically behaves as a semi-infinite layer with modified dielectric function calculated by the Landau-Lifshitz-Looyenga (LLL) model from the dielectric function of a smooth metal, the dielectric function of TCO and just one free parameter that needs to be found by fitting the total optical absorptance. This approach can be used to simplify the modelling of the optical properties of thin film solar cells. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  1. Textured conducting glass by nanosphere lithography for increased light absorption in thin-film solar cells

    International Nuclear Information System (INIS)

    Nanoscale surface texturing in thin-film solar cells has been shown to enhance device efficiency by increasing light absorption through reduced reflectance and increased light scattering across a broad range of wavelengths and angles. However, light trapping in the industrial thin-film cells is still sub-optimal and creating optimized nanoscale texture over a large area remains challenging. In this article, we present a well-controlled low-cost process to fabricate a periodic nanocone texture optimized for maximum light absorption in thin-film microcrystalline silicon solar cells. The texture is fabricated using nanosphere lithography with the period controlled by the nanosphere diameter and the texture shape and aspect ratio controlled by the reactive ion etching conditions. Finite-difference time-domain optical simulations are used to optimize the texture in the state-of-the-art microcrystalline cells, and optical absorption measurements show that the same cells fabricated on the optimized nanocone-textured substrates exhibit a relative short-circuit current increase of close to 30% compared to a reference state-of-the-art cell with a randomly textured zinc oxide layer. This nanocone texturing technique is compatible with standard thin-film cell fabrication processes and can also be used for other thin-film cells (CIGS, CdTe, CZTS, etc) to maximize light absorption and minimize layer thickness enabling more efficient carrier collection and lower overall cost. (paper)

  2. Textured conducting glass by nanosphere lithography for increased light absorption in thin-film solar cells

    Science.gov (United States)

    Mailoa, Jonathan P.; Seog Lee, Yun; Buonassisi, Tonio; Kozinsky, Inna

    2014-02-01

    Nanoscale surface texturing in thin-film solar cells has been shown to enhance device efficiency by increasing light absorption through reduced reflectance and increased light scattering across a broad range of wavelengths and angles. However, light trapping in the industrial thin-film cells is still sub-optimal and creating optimized nanoscale texture over a large area remains challenging. In this article, we present a well-controlled low-cost process to fabricate a periodic nanocone texture optimized for maximum light absorption in thin-film microcrystalline silicon solar cells. The texture is fabricated using nanosphere lithography with the period controlled by the nanosphere diameter and the texture shape and aspect ratio controlled by the reactive ion etching conditions. Finite-difference time-domain optical simulations are used to optimize the texture in the state-of-the-art microcrystalline cells, and optical absorption measurements show that the same cells fabricated on the optimized nanocone-textured substrates exhibit a relative short-circuit current increase of close to 30% compared to a reference state-of-the-art cell with a randomly textured zinc oxide layer. This nanocone texturing technique is compatible with standard thin-film cell fabrication processes and can also be used for other thin-film cells (CIGS, CdTe, CZTS, etc) to maximize light absorption and minimize layer thickness enabling more efficient carrier collection and lower overall cost.

  3. Hydrogen passivation of polycrystalline Si thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Gorka, Benjamin

    2010-12-15

    Hydrogen passivation is a key process step in the fabrication of polycrystalline Si (poly-Si) thin film solar cells. In this work a parallel plate rf plasma setup was used for the hydrogen passivation treatment. The main topics that have been investigated are (i) the role of plasma parameters (like hydrogen pressure, electrode gap and plasma power), (ii) the dynamics of the hydrogen treatment and (iii) passivation of poly-Si with different material properties. Passivation was characterized by measuring the open-circuit voltage V{sub OC} of poly-Si reference samples. Optimum passivation conditions were found by measurements of the breakdown voltage V{sub brk} of the plasma for different pressures p and electrode gaps d. For each pressure, the best passivation was achieved at a gap d that corresponded to the minimum in V{sub brk}. Plasma simulations were carried out, which indicate that best V{sub OC} corresponds to a minimum in ion energy. V{sub OC} was not improved by a larger H flux. Investigations of the passivation dynamic showed that a plasma treatment in the lower temperature range ({<=}400 C) is slow and takes several hours for the V{sub OC} to saturate. Fast passivation can be successfully achieved at elevated temperatures around 500 C to 600 C with a plateau time of 10 min. It was found that prolonged hydrogenation leads to a loss in V{sub OC}, which is less pronounced within the observed optimum temperature range (500 C-600 C). Electron beam evaporation has been investigated as an alternative method to fabricate poly-Si absorbers. The material properties have been tuned by alteration of substrate temperature T{sub dep}=200-700 C and were characterized by Raman, ESR and V{sub OC} measurements. Largest grains were obtained after solid phase crystallization (SPC) of a-Si, deposited in the temperature range of 300 C. The defect concentration of Si dangling bonds was lowered by passivation by about one order of magnitude. The lowest dangling bond concentration of 2.5.10{sup 16} cm{sup -3} after passivation was found for poly-Si with largest grains and coincides with best solar cell results, obtained after rapid thermal annealing and hydrogen passivation. Hydrogen passivation of poly-Si films was successfully achieved with a parallel plate rf H plasma treatment at elevated temperatures around 500 C to 600 C. Yet it seems that treatment induced defect generation causes a loss in V{sub OC} with prolonged passivation time and should be minimized. In order to achieve high open circuit voltages larger than 450 mV, in addition to hydrogen passivation, low recombination at the interfaces becomes more and more important. (orig.)

  4. Cost-effective nanostructured thin-film solar cell with enhanced absorption

    Science.gov (United States)

    Wang, Peng Hui; Nowak, Regina-Elisabeth; Geißendörfer, Stefan; Vehse, Martin; Reininghaus, Nies; Sergeev, Oleg; von Maydell, Karsten; Brolo, Alexandre G.; Agert, Carsten

    2014-11-01

    Nanostructured transparent conductive electrodes are highly interesting for efficient light management in thin-film solar cells, but they are often costly to manufacture and limited to small scales. This work reports on a low-cost and scalable bottom-up approach to fabricate nanostructured thin-film solar cells. A folded solar cell with increased optical absorber volume was deposited on honeycomb patterned zinc oxide nanostructures, fabricated in a combined process of nanosphere lithography and electrochemical deposition. The periodicity of the honeycomb pattern can be easily varied in the fabrication process, which allows structural optimization for different absorber materials. The implementation of this concept in amorphous silicon thin-film solar cells with only 100 nm absorber layer was demonstrated. The nanostructured solar cell showed approximately 10% increase in the short circuit current density compared to a cell on an optimized commercial textured reference electrode. The concept presented here is highly promising for low-cost industrial fabrication of nanostructured thin-film solar cells, since no sophisticated layer stacks or expensive techniques are required.

  5. Transparent conductive zinc oxide basics and applications in thin film solar cells

    CERN Document Server

    Klein, Andreas; Rech, Bernd

    2008-01-01

    Zinc oxide (ZnO) belongs to the class of transparent conducting oxides which can be used as transparent electrodes in electronic devices or heated windows. In this book the material properties of, the deposition technologies for, and applications of zinc oxide in thin film solar cells are described in a comprehensive manner. Structural, morphological, optical and electronic properties of ZnO are treated in this review. The editors and authors of this book are specialists in deposition, analysis and fabrication of thin-film solar cells and especially of ZnO. This book is intended as an overview and a data collection for students, engineers and scientist.

  6. Grain boundaries in Cu(In,Ga)(Se,S){sub 2} thin-film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Rau, Uwe [Forschungszentrum Juelich, IEF5-Photovoltaik, Juelich (Germany); Taretto, Kurt [Universidad Nacional del Comahue, Dto. de Electrotecnia, Buenos Aires, Neuquen (Argentina); Siebentritt, Susanne [Universite du Luxembourg, Luxembourg (Luxembourg)

    2009-07-15

    The paper reviews the current status of the research on grain boundaries in polycrystalline Cu(In,Ga)(S,Se){sub 2} alloys used as absorber materials for thin-film solar cells. We discuss the different concepts that are available to explain the relatively low electronic activity of grain boundaries in these materials. Numerical simulations that have been undergone so far to model the polycrystalline solar cells are briefly summarized. In addition, we give an overview on the experiments that have been conducted so far to elucidate the structural, defect-chemical, and electronic properties of grain boundaries in Cu(In,Ga)(S,Se){sub 2} thin-films. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

    2012-09-01

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

  8. Transparent high-performance CDSE thin-film solar cells

    International Nuclear Information System (INIS)

    Simulations indicate that 25-30% efficiency can be achieved with a four-terminal thin-film tandem structure. The bottom low band gap cell can be CuIn1-xGa xSe2, and CdSe is proposed as the top cell, as it has an ideal band gap of 1.7 eV. In addition to the efficiency requirements, the top cell must also be transparent to effectively transmit sub band gap light to the bottom cell. We have developed CdSe devices that meet many of the requirements of this tandem structure. High electronic quality CdSe has been deposited on SnO2 and ZnO, which serve as the transparent n-type contact. The p-type transparent contact is ZnSe/Cu. Voc's of 475 mV have been achieved and can be further improved with better contacts. However, record Jsc's in excess of 17 mA/cm2 have been achieved. This is close to the target 18 mA/cm2 to meet the efficiency objectives. Transmission of 80% of the sub band gap radiation has been demonstrated for 2-no. muno. m-thick absorber layers. This is also close to the 85% target to achieve the overall tandem efficiency objectives. Improvement of the contact layers to achieve the Voc target is the final challenge

  9. 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.

  10. Properties of ITO-AZO bilayer thin films prepared by magnetron sputtering for applications in thin-film silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Chao; Mao, Yanli [Henan University, Henan Key Laboratory of Photovoltaic Materials, School of Physics and Electronics, Kaifeng (China); Zeng, Xiangbo [Chinese Academy of Sciences, Key Laboratory of Semiconductor Materials, Beijing (China)

    2013-01-15

    In this paper we study the electro-optical behavior and the application of indium-tin oxide (ITO) and aluminum-doped zinc oxide (AZO) bilayer thin films for silicon solar cells. ITO-AZO bilayer thin films were deposited on glass substrates using radio-frequency magnetron sputtering. The experimental results show that a decrease in the electrical resistivity of the ITO-AZO bilayer thin films has been achieved without significant degradation of optical properties. In the best case the resistivity of the bilayer films reached a minimum of 5.075 x 10{sup -4} {Omega} cm when the thickness of the AZO buffer layer was 12 nm. The ITO-AZO bilayer films were applied as the front electrodes of amorphous silicon solar cells and the short-circuit current density of the solar cells was considerably increased. (orig.)

  11. Characterization of Thin Films for Polymer Solar Cells

    DEFF Research Database (Denmark)

    Tromholt, Thomas

    2012-01-01

    The field of polymer solar cells has undergone an extensive development in recent years after the invention of semiconducting polymers in 1991. Efficiencies have gradually increased to above 10 %, and high throughput processing methods such as roll-to-roll coating allow for production of thousands of solar cells with low embedded time, material, and energy consumption as compared to silicon solar cells. Consequently, different demonstration products of small mobile gadgets based on polymer solar...

  12. Nanoscale investigation of potential distribution in operating Cu(In,Ga)Se2 thin-film solar cells

    OpenAIRE

    Zhang, Zhenhao

    2013-01-01

    Thin-film solar cells based on CIGS absorber materials show the highest power conversion efficiency among all kinds of thin-film solar cells. The distribution of the electrostatic potential in and between the materials in the solar cell has obviously a major impact on the superior performance of the device. This thesis reported on imaging of the electrostatic potential on untreated cross sections of operating CIGS solar cells using Kelvin probe force microscopy.

  13. Thin-Film Solar Cells Based on Amorphous and Microcrystalline Silicon

    Science.gov (United States)

    Ballif, Christophe; Despeisse, Matthieu; Haug, Franz-Josef

    2015-10-01

    The following sections are included: * Introduction * Basic properties of amorphous and microcrystalline silicon alloys * Thin-film silicon solar cells * Fabrication of device-grade amorphous and microcrystalline silicon * Light management * Advanced device architecture and record devices * Industrialisation and large-area production technology * Acknowledgements * References

  14. Carrier transport in polycrystalline silicon thin films solar cells grown on a highly textured structure.

    Czech Academy of Sciences Publication Activity Database

    Honda, Shinya; Takakura, H.; Hamakawa, Y.; Muhida, R.; Kawamura, T.; Harano, T.; Toyama, T.; Okamoto, H.

    2004-01-01

    Ro?. 43, 9A (2004), s. 5955-5959. ISSN 0021-4922 Institutional research plan: CEZ:AV0Z1010914 Keywords : polycrystalline silicon thin film * solar cells * substrate texture Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.142, year: 2004

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

    Czech Academy of Sciences Publication Activity Database

    Ledinský, Martin; Moulin, E.; Bugnon, G.; Ganzerová, Kristína; Vetushka, Aliaksi; Meillaud, F.; Fejfar, Antonín; Ballif, C.

    2014-01-01

    Ro?. 105, ?. 11 (2014), "111106-1"-"111106-4". ISSN 0003-6951 EU Projects: European Commission(XE) 283501 Institutional support: RVO:68378271 Keywords : light trapping * microcrystalline silicon * thin film solar cell * Raman spectroscopy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.302, year: 2014

  16. Disorder improves nanophotonic light trapping in thin-film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Paetzold, U. W., E-mail: u.paetzold@fz-juelich.de; Smeets, M.; Meier, M.; Bittkau, K.; Merdzhanova, T.; Smirnov, V.; Carius, R.; Rau, U. [IEK5—Photovoltaik, Forschungszentrum Jülich GmbH, 52425 Jülich (Germany); Michaelis, D.; Waechter, C. [Fraunhofer Institut für Angewandte Optik und Feinmechanik, Albert Einstein Str. 7, D-07745 Jena (Germany)

    2014-03-31

    We present a systematic experimental study on the impact of disorder in advanced nanophotonic light-trapping concepts of thin-film solar cells. Thin-film solar cells made of hydrogenated amorphous silicon were prepared on imprint-textured glass superstrates. For periodically textured superstrates of periods below 500?nm, the nanophotonic light-trapping effect is already superior to state-of-the-art randomly textured front contacts. The nanophotonic light-trapping effect can be associated to light coupling to leaky waveguide modes causing resonances in the external quantum efficiency of only a few nanometer widths for wavelengths longer than 500?nm. With increasing disorder of the nanotextured front contact, these resonances broaden and their relative altitude decreases. Moreover, overall the external quantum efficiency, i.e., the light-trapping effect, increases incrementally with increasing disorder. Thereby, our study is a systematic experimental proof that disorder is conceptually an advantage for nanophotonic light-trapping concepts employing grating couplers in thin-film solar cells. The result is relevant for the large field of research on nanophotonic light trapping in thin-film solar cells which currently investigates and prototypes a number of new concepts including disordered periodic and quasi periodic textures.

  17. Disorder improves nanophotonic light trapping in thin-film solar cells

    International Nuclear Information System (INIS)

    We present a systematic experimental study on the impact of disorder in advanced nanophotonic light-trapping concepts of thin-film solar cells. Thin-film solar cells made of hydrogenated amorphous silicon were prepared on imprint-textured glass superstrates. For periodically textured superstrates of periods below 500?nm, the nanophotonic light-trapping effect is already superior to state-of-the-art randomly textured front contacts. The nanophotonic light-trapping effect can be associated to light coupling to leaky waveguide modes causing resonances in the external quantum efficiency of only a few nanometer widths for wavelengths longer than 500?nm. With increasing disorder of the nanotextured front contact, these resonances broaden and their relative altitude decreases. Moreover, overall the external quantum efficiency, i.e., the light-trapping effect, increases incrementally with increasing disorder. Thereby, our study is a systematic experimental proof that disorder is conceptually an advantage for nanophotonic light-trapping concepts employing grating couplers in thin-film solar cells. The result is relevant for the large field of research on nanophotonic light trapping in thin-film solar cells which currently investigates and prototypes a number of new concepts including disordered periodic and quasi periodic textures

  18. Study of GaAs(Ti) thin films as candidates for IB solar cells manufacturing

    OpenAIRE

    Silvestre, S.; Boronat, A.; Castaner, L.; Fuertes Marrón, David; Martí Vega, Antonio; Luque López, Antonio

    2010-01-01

    Thin films of GaAs(Ti) have been deposited by sputtering on glass and n_GaAs substrates under different process conditions. Optical characteristics of these samples have been analyzed to study the potential of this material in intermediate Band solar cell manufacturing

  19. Study of GaAs(Ti) thin films as candidates for IB solar cells manufacturing

    OpenAIRE

    Silvestre Bergés, Santiago; Boronat, A.; Castañer Muñoz, Luis María

    2010-01-01

    Thin films of GaAs(Ti) have been deposited by sputtering on glass and n_GaAs substrates under different process conditions. Optical characteristics of these samples have been analyzed to study the potential of this material in intermediate Band solar cell manufacturing.

  20. New materials and deposition techniques for highly efficient silicon thin film solar cells.

    Czech Academy of Sciences Publication Activity Database

    Rech, B.; Kluth, O.; Repmann, T.; Roschek, T.; Špringer, Ji?í; Muller, J.; Finger, F.; Stiebig, H.; Wagner, H.

    2002-01-01

    Ro?. 74, - (2002), s. 439-447. ISSN 0927-0248 Grant ostatní: BMWi(DE) 0329885; BMWi(DE) 0329854A; ENK6-CT(XE) 2000-00321 Institutional research plan: CEZ:AV0Z1010914 Keywords : thin film solar cell * silicon * zinc oxide Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.258, year: 2002

  1. 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.

  2. Low cost and high performance light trapping structure for thin-film solar cells

    CERN Document Server

    Wang, DongLin; Su, Gang

    2015-01-01

    Nano-scaled dielectric and metallic structures are popular light tapping structures in thin-film solar cells. However, a large parasitic absorption in those structures is unavoidable. Most schemes based on such structures also involve the textured active layers that may bring undesirable degradation of the material quality. Here we propose a novel and cheap light trapping structure based on the prism structured SiO2 for thin-film solar cells, and a flat active layer is introduced purposefully. Such a light trapping structure is imposed by the geometrical shape optimization to gain the best optical benefit. By examining our scheme, it is disclosed that the conversion efficiency of the flat a-Si:H thin-film solar cell can be promoted to exceed the currently certified highest value. As the cost of SiO2-based light trapping structure is much cheaper and easier to fabricate than other materials, this proposal would have essential impact and wide applications in thin-film solar cells.

  3. Light Harvesting Schemes for High Efficiency Thin Film Silicon Solar Cells

    OpenAIRE

    Despeisse, Matthieu; Boccard, Mathieu; Battaglia, Corsin; Bugnon, Gregory; Charriere, Mathieu; Garcia, Loic; Bonnet-Eymard, Maximilien; Escarre, Jordi; Cuony, Peter; Stuckelberger, Michael; Parascandolo, Gaetano; Haenni, Simon; Loefgren, Linus; Schuettauf, Jan-Willem; Ding, Laura

    2012-01-01

    In Thin Film Silicon (TF-Si) solar cells light harvesting schemes must guarantee an efficient light trapping in the thin absorber layers without decreasing the silicon layers quality and consecutively the p-i-n diodes electrical performance. TF-Si solar cells resilience to the substrate roughness is reported to be possibly improved through optimizations of the cell design and of the silicon deposition processes. By further tailoring the superstrate texture, amorphous silicon / microcrystallin...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-06-11

    Tandem solar cells (TSCs), which use two or more materials to absorb sunlight, have achieved power conversion efficiencies of >25% versus 11-20% for commercialized single junction solar cell modules. The key to widespread commercialization of TSCs is to develop the wide-band, top solar cell that is both cheap to fabricate and has a high open-circuit voltage (i.e. >1V). Previous work in TSCs has generally focused on using expensive processing techniques with slow growth rates resulting in costs that are two orders of magnitude too expensive to be used in conventional solar cell modules. The objective of the PLANT PV proposal was to investigate the feasibility of using Ag(In,Ga)Se2 (AIGS) as the wide-bandgap absorber in the top cell of a thin film tandem solar cell (TSC). Despite being studied by very few in the solar community, AIGS solar cells have achieved one of the highest open-circuit voltages within the chalcogenide material family with a Voc of 949mV when grown with an expensive processing technique (i.e. Molecular Beam Epitaxy). PLANT PV�s goal in Phase I of the DOE SBIR was to 1) develop the chemistry to grow AIGS thin films via solution processing techniques to reduce costs and 2) fabricate new device architectures with high open-circuit voltage to produce full tandem solar cells in Phase II. PLANT PV attempted to translate solution processing chemistries that were successful in producing >12% efficient Cu(In,Ga)Se2 solar cells by replacing copper compounds with silver. The main thrust of the research was to determine if it was possible to make high quality AIGS thin films using solution processing and to fully characterize the materials properties. PLANT PV developed several different types of silver compounds in an attempt to fabricate high quality thin films from solution. We found that silver compounds that were similar to the copper based system did not result in high quality thin films. PLANT PV was able to deposit AIGS thin films using a mixture of solution and physical vapor deposition processing, but these films lacked the p-type doping levels that are required to make decent solar cells. Over the course of the project PLANT PV was able to fabricate efficient CIGS solar cells (8.7%) but could not achieve equivalent performance using AIGS. During the nine-month grant PLANT PV set up a variety of thin film characterization tools (e.g. drive-level capacitance profiling) at the Molecular Foundry, a Department of Energy User Facility, that are now available to both industrial and academic researchers via the grant process. PLANT PV was also able to develop the back end processing of thin film solar cells at Lawrence Berkeley National Labs to achieve 8.7% efficient CIGS solar cells. This processing development will be applied to other types of thin film PV cells at the Lawrence Berkeley National Labs. While PLANT PV was able to study AIGS film growth and optoelectronic properties we concluded that AIGS produced using these methods would have a limited efficiency and would not be commercially feasible. PLANT PV did not apply for the Phase II of this grant.

  5. Photovoltaic Technology: The Case for Thin-Film Solar Cells

    OpenAIRE

    Shah, Arvind; TORRES, P.; Tscharner, Reto; Wyrsch, N; Keppner H

    2013-01-01

    The advantages and limitations of photovoltaic solar modules for energy generation are reviewed with their operation principles and physical efficiency limits. Although the main materials currently used or investigated and the associated fabrication technologies are individually described, emphasis is on silicon-based solar cells. Wafer-based crystalline silicon solar modules dominate in terms of production, but amorphous silicon solar cells have the potential to undercut costs owing, for exa...

  6. Low resistivity molybdenum thin film towards the back contact of dye-sensitized solar cell

    Indian Academy of Sciences (India)

    Vuong Son; Tran Thi Ha; Luong T Thu Thuy; Nguyen Ngoc Ha; Nguyen Duc Chien; Mai Anh Tuan

    2015-12-01

    This paper reports the optimization of the molybdenum thin film electrode as the back contact of dye-sensitized solar cell (DSSC). The molybdenum thin film was grown on the glass substrate by direct current sputtering techniques of which the sputtering power was 150Wat 18 sccm flow rate of Ar. At such sputtering parameters, the Mo film can reach the lowest resistivity of 1.28E?6 cm at 400 nm thick. And the reflection of Mo membrane was 82%. This value is considered as a very good result for preparation of the back contact of DSSC.

  7. Surface Engineering of ZnO Thin Film for High Efficiency Planar Perovskite Solar Cells

    Science.gov (United States)

    Tseng, Zong-Liang; Chiang, Chien-Hung; Wu, Chun-Guey

    2015-01-01

    Sputtering made ZnO thin film was used as an electron-transport layer in a regular planar perovskite solar cell based on high quality CH3NH3PbI3 absorber prepared with a two-step spin-coating. An efficiency up to 15.9% under AM 1.5G irradiation is achieved for the cell based on ZnO film fabricated under Ar working gas. The atmosphere of the sputtering chamber can tune the surface electronic properties (band structure) of the resulting ZnO thin film and therefore the photovoltaic performance of the corresponding perovskite solar cell. Precise surface engineering of ZnO thin film was found to be one of the key steps to fabricate ZnO based regular planar perovskite solar cell with high power conversion efficiency. Sputtering method is proved to be one of the excellent techniques to prepare ZnO thin film with controllable properties. PMID:26411577

  8. Surface Engineering of ZnO Thin Film for High Efficiency Planar Perovskite Solar Cells.

    Science.gov (United States)

    Tseng, Zong-Liang; Chiang, Chien-Hung; Wu, Chun-Guey

    2015-01-01

    Sputtering made ZnO thin film was used as an electron-transport layer in a regular planar perovskite solar cell based on high quality CH3NH3PbI3 absorber prepared with a two-step spin-coating. An efficiency up to 15.9% under AM 1.5G irradiation is achieved for the cell based on ZnO film fabricated under Ar working gas. The atmosphere of the sputtering chamber can tune the surface electronic properties (band structure) of the resulting ZnO thin film and therefore the photovoltaic performance of the corresponding perovskite solar cell. Precise surface engineering of ZnO thin film was found to be one of the key steps to fabricate ZnO based regular planar perovskite solar cell with high power conversion efficiency. Sputtering method is proved to be one of the excellent techniques to prepare ZnO thin film with controllable properties. PMID:26411577

  9. Comparison of periodic and random structures for scattering in thin-film microcrystalline silicon solar cells

    OpenAIRE

    Peters, Marius; Forberich, Karen; Battaglia, Corsin; Armin G. Aberle; Bläsi, Bénédikt

    2012-01-01

    Random structures are typically used for light trapping in thin-film silicon solar cells. However, theoretically periodic structures can outperform random structures in such applications. In this paper we compare random and periodic structures of similar shape. Both types of structure are based on atomic force microscopy (AFM) scans of a sputtered and etched ZnO layer. The absorption in a solar cell on both structures was calculated and compared to external quantum efficiency (EQE) measuremen...

  10. Optics of thin-film silicon solar cells with efficient periodic light trapping textures

    Science.gov (United States)

    Haase, C.; Knipp, D.; Stiebig, H.

    2007-09-01

    The principle of interaction of light waves incident on a surface with a subwavelength nanostructure is a key question in the development of solar cells. Efficient thin-film solar cells based on microcrystalline silicon (?c-Si:H) or amorphous silicon (a-Si:H) with an absorber layer in the micrometer range require effective light trapping and an optimal incoupling of the entire sun spectrum. The established approach to achieve this is the application of randomly textured transparent conductive oxides (TCOs). Previous investigations of light trapping in thin-film devices have been conducted with often misleading far field measurements. Optical simulations based on the Finite Integration Technique (CST Microwave Studios) are a valuable approach to analyze the light propagation in thin-film devices and enable the study the subwavelength optics of nano-textured interfaces by solving the Maxwell equations rigorously in 3D. However, the question regarding the optimized lateral feature size, vertical height, resulting interface angle and shape of the texture is essential to reach high energy conversion efficiencies. Various texture designs are studied by numerical modeling. We present a 3D simulation analysis of thin-film silicon solar cell nano-optics that gives clear design criteria to reach high efficiencies.

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

    Science.gov (United States)

    Ra?iukaitis, G.; Ge?ys, P.; Gedvilas, M.; Regelskis, K.; Voisiat, B.

    2010-10-01

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

  12. ANNEALING OF POLYCRYSTALLINE THIN FILM SILICON SOLAR CELLS IN WATER VAPOUR AT SUB-ATMOSPHERIC PRESSURES

    Directory of Open Access Journals (Sweden)

    Peter Pikna

    2014-10-01

    Full Text Available Thin film polycrystalline silicon (poly-Si solar cells were annealed in water vapour at pressures below atmospheric pressure. PN junction of the sample was contacted by measuring probes directly in the pressure chamber filled with steam during passivation. Suns-VOC method and a Lock-in detector were used to monitor an effect of water vapour to VOC of the solar cell during whole passivation process (in-situ. Tested temperature of the sample (55°C – 110°C was constant during the procedure. Open-circuit voltage of a solar cell at these temperatures is lower than at room temperature. Nevertheless, voltage response of the solar cell to the light flash used during Suns-VOC measurements was good observable. Temperature dependences for multicrystalline wafer-based and polycrystalline thin film solar cells were measured and compared. While no significant improvement of thin film poly-Si solar cell parameters by annealing in water vapour at under-atmospheric pressures was observed up to now, in-situ observation proved required sensitivity to changing VOC at elevated temperatures during the process.

  13. Computational and experimental study of a multi-layer absorptivity enhanced thin film silicon solar cell

    International Nuclear Information System (INIS)

    We report on the computational design, fabrication and validation of a multi-layer silicon based thin film solar cell. The cell structure consists of a thin absorber layer of amorphous silicon deposited on a back-reflector aluminum layer and coated on top with ITO transparent conductive oxide. The structure is mounted on a glass substrate. We first use constrained optimization techniques along with numerical solvers of the electromagnetic equations (i.e. FDTD) to tune the geometry of the design. The resulting structure suggests that photon absorptivity in the thin film silicon can be enhanced by as much as 100% over the uncoated layer. The proposed design is then fabricated using thin film deposition techniques, along with a control sample of bare silicon absorber for comparison. AFM imaging and spectrophotometry experiments are applied to image and record the surface roughness and measure the reflectivity spectrum of the sample. Using the measured reflectivity spectrum, we then use inverse optimization to estimate the realized thin film dimensions, deposition error and unwanted oxidation volume. At the end, we use a statistical Monte Carlo analysis as a second method of verification to demonstrate that the measured spectra are in accordance with the expected curves from simulation, and to estimate the effects of fabrication error. - Highlights: • Design, fabrication and validation of multi-layer silicon solar cell are studied. • The cell consists of aluminum, amorphous silicon and ITO layers. • The proposed designs are fabricated by deposition techniques. • Inverse optimization is used to estimate the realized dimensions and errors

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

    Energy Technology Data Exchange (ETDEWEB)

    Chu, T.L. (University of South Florida, Tampa, FL (United States))

    1992-04-01

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

  15. Photon management in thin-film solar cells; Photon-Management in Duennschicht-Solarzellen

    Energy Technology Data Exchange (ETDEWEB)

    Fahr, Stephan

    2011-11-22

    In this thesis procedures were presented, which modify the propagation of the incident light in such a way that by this the efficiency of thin-film solar cells is increased. The strength of the presented numerical studies lies thereby in the rigorous solution of Maxwell's equations. Fundamental statements concerning the lay-out of an ideal texture could be made, which for present thin-film solar cells over the whole relevant spectral range both suppresses reflection losses and leads to an elongation of the effective path. Object of the thesis was also the design of a spectral- and angular-selective filter, which confines the acceptance angle of a solar cell with the aim of an improved absorption in the long-wave spectral region. Furthermore also tandem cells on the base of amorphous and microcrystalline silicon were studied.

  16. Laser process for extended silicon thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Hessmann, M.T., E-mail: hessmann@zae.uni-erlangen.de [Bavarian Center for Applied Energy Research, Am Weichselgarten 7, 91058 Erlangen (Germany); Kunz, T.; Burkert, I.; Gawehns, N. [Bavarian Center for Applied Energy Research, Am Weichselgarten 7, 91058 Erlangen (Germany); Schaefer, L.; Frick, T.; Schmidt, M. [Bayerisches Laserzentrum, Konrad-Zuse-Str 2-6, 91052 Erlangen (Germany); Meidel, B. [Schott Solar AG, Carl-Zeiss-Strasse 4, 63755 Alzenau (Germany); Auer, R. [Bavarian Center for Applied Energy Research, Am Weichselgarten 7, 91058 Erlangen (Germany); Brabec, C.J. [Bavarian Center for Applied Energy Research, Am Weichselgarten 7, 91058 Erlangen (Germany); Chair VI - Materials for Electronics and Energy Technology, University of Erlangen-Nuremberg, Martensstrasse 7, 91058 Erlangen (Germany)

    2011-10-31

    We present a large area thin film base substrate for the epitaxy of crystalline silicon. The concept of epitaxial growth of silicon on large area thin film substrates overcomes the area restrictions of an ingot based monocrystalline silicon process. Further it opens the possibility for a roll to roll process for crystalline silicon production. This concept suggests a technical pathway to overcome the limitations of silicon ingot production in terms of costs, throughput and completely prevents any sawing losses. The core idea behind these thin film substrates is a laser welding process of individual, thin silicon wafers. In this manuscript we investigate the properties of laser welded monocrystalline silicon foils (100) by micro-Raman mapping and spectroscopy. It is shown that the laser beam changes the crystalline structure of float zone grown silicon along the welding seam. This is illustrated by Raman mapping which visualizes compressive stress as well as tensile stress in a range of - 147.5 to 32.5 MPa along the welding area.

  17. Light-trapping design of graphene transparent electrodes for efficient thin-film silicon solar cells.

    Science.gov (United States)

    Zhao, Yongxiang; Chen, Fei; Shen, Qiang; Zhang, Lianmeng

    2012-09-01

    In this paper, the performance of solar cells with graphene transparent electrodes is compared with cells using conventional indium tin oxide (ITO) electrodes, and it is demonstrated the optical absorption of solar cells with bare graphene structure is worse than that of bare ITO structure because of the higher refractive index of graphene. To enhance the light trapping of graphene-based thin-film solar cells, a simple two-layer SiO(2)/SiC structure is proposed as antireflection coatings deposited on top of graphene transparent electrodes, and the thickness of each layer is optimized by differential evolution in order to enhance the optical absorption of a-Si:H thin-film solar cells to the greatest degree. The optimization results demonstrate the optimal SiO(2)/SiC/graphene structure can obtain 37.30% enhancement with respect to bare ITO structure, which has obviously exceeded the light-trapping enhancement of 34.15% for the optimal SiO(2)/SiC/ITO structure. Therefore, with the aid of the light-trapping structure, the graphene films are a very promising indium-free transparent electrode substitute for the conventional ITO electrode for use in cost-efficient thin-film silicon solar cells. PMID:22945173

  18. Thin film solar cell inflatable ultraviolet rigidizable deployment hinge

    Science.gov (United States)

    Simburger, Edward J. (Inventor); Matsumoto, James H. (Inventor); Giants, Thomas W. (Inventor); Garcia, III, Alec (Inventor); Perry, Alan R. (Inventor); Rawal, Suraj (Inventor); Marshall, Craig H. (Inventor); Lin, John K. H. (Inventor); Day, Jonathan Robert (Inventor); Kerslake, Thomas W. (Inventor)

    2010-01-01

    A flexible inflatable hinge includes curable resin for rigidly positioning panels of solar cells about the hinge in which wrap around contacts and flex circuits are disposed for routing power from the solar cells to the power bus further used for grounding the hinge. An indium tin oxide and magnesium fluoride coating is used to prevent static discharge while being transparent to ultraviolet light that cures the embedded resin after deployment for rigidizing the inflatable hinge.

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

    Science.gov (United States)

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

    2006-05-30

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

  20. Water vapour passivation of poly-Si thin film solar cells.

    Czech Academy of Sciences Publication Activity Database

    Pikna, Peter; Fejfar, Antonín; Pí?, Vlastimil; Müller, Martin; Ledinský, Martin; Vetushka, Aliaksi; Ko?ka, Jan

    München : WIP Wirtschaft und Infrastruktur GmbH & Co Planungs KG, 2012 - (Nowak, S.), s. 2393-2395 ISBN 3-936338-28-0. [European Photovoltaic Solar Energy Conference and Exhibition (PVSEC) /17./. Frankfurt (DE), 24.09.2012-28.09.2012] EU Projects: European Commission(XE) 240826 Institutional research plan: CEZ:AV0Z10100521 Keywords : polycrystalline * silicon * thin film solar cell * water vapour passivation * in situ investigation * Suns-Voc Subject RIV: BM - Solid Matter Physics ; Magnetism

  1. Advanced electrical simulation of thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Burgelman, Marc, E-mail: Marc.Burgelman@elis.ugent.be; Decock, Koen; Khelifi, Samira; Abass, Aimi

    2013-05-01

    Advanced electrical simulation of copper indium gallium diselenide solar cells is illustrated by setting up a demonstration case in SCAPS (Solar Cell Capacitance Simulator), the solar cell simulation programme of the University of Gent. The model includes band gap grading, multivalent defects and metastable transitions between defects. This simplified demonstration model clearly and quantitatively illustrates some topics that were extensively discussed in recent literature: metastable defects exist in either an acceptor or in a donor configuration; the occupation of these configurations is set during initial conditions at higher temperature, and then frozen in during cell operation at lower temperature. These occupations can strongly influence the effective doping profile in the absorber, and hence possible energy barriers in the structure. The dependence of such barriers on the initial conditions and on the operating voltage can cause a considerable dependence of the current–voltage characteristics on the initial conditions, especially of the fill factor. At the same time, the demonstration model illustrates some of the recent extensions of SCAPS. - Highlights: ? SCAPS, the Solar Cell Capacitance Simulator of UGent is freely available. ? SCAPS is keeping up with the sophistication of state-of-the-art solar cells. ? It can now handle: multivalent and metastable defects; grading of all properties. ? It is shown how metastable defects can lead to metastable cell characteristics. ? A relation conduction band barrier-fill factor is numerically established.

  2. Advanced electrical simulation of thin film solar cells

    International Nuclear Information System (INIS)

    Advanced electrical simulation of copper indium gallium diselenide solar cells is illustrated by setting up a demonstration case in SCAPS (Solar Cell Capacitance Simulator), the solar cell simulation programme of the University of Gent. The model includes band gap grading, multivalent defects and metastable transitions between defects. This simplified demonstration model clearly and quantitatively illustrates some topics that were extensively discussed in recent literature: metastable defects exist in either an acceptor or in a donor configuration; the occupation of these configurations is set during initial conditions at higher temperature, and then frozen in during cell operation at lower temperature. These occupations can strongly influence the effective doping profile in the absorber, and hence possible energy barriers in the structure. The dependence of such barriers on the initial conditions and on the operating voltage can cause a considerable dependence of the current–voltage characteristics on the initial conditions, especially of the fill factor. At the same time, the demonstration model illustrates some of the recent extensions of SCAPS. - Highlights: ? SCAPS, the Solar Cell Capacitance Simulator of UGent is freely available. ? SCAPS is keeping up with the sophistication of state-of-the-art solar cells. ? It can now handle: multivalent and metastable defects; grading of all properties. ? It is shown how metastable defects can lead to metastable cell characteristics. ? A relation conduction band barrier-fill factor is numerically established

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

    Energy Technology Data Exchange (ETDEWEB)

    Birkmire, R.W.; Phillips, J.E. [Univ. of Delaware, Newark, DE (United States). Institute of Energy Conversion

    1997-11-01

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

  4. Angular behavior of the absorption limit in thin film silicon solar cells

    CERN Document Server

    Naqavi, Ali; Söderström, Karin; Battaglia, Corsin; Paeder, Vincent; Scharf, Toralf; Herzig, Hans Peter; Ballif, Christophe

    2013-01-01

    We investigate the angular behavior of the upper bound of absorption provided by the guided modes in thin film solar cells. We show that the 4n^2 limit can be potentially exceeded in a wide angular and wavelength range using two-dimensional periodic thin film structures. Two models are used to estimate the absorption enhancement; in the first one, we apply the periodicity condition along the thickness of the thin film structure but in the second one, we consider imperfect confinement of the wave to the device. To extract the guided modes, we use an automatized procedure which is established in this work. Through examples, we show that from the optical point of view, thin film structures have a high potential to be improved by changing their shape. Also, we discuss the nature of different optical resonances which can be potentially used to enhance light trapping in the solar cell. We investigate the two different polarization directions for one-dimensional gratings and we show that the transverse magnetic pola...

  5. Development of thin-film polycrystalline silicon solar cells by a solid phase crystallization (SPC) method

    Energy Technology Data Exchange (ETDEWEB)

    Matsuyama, Takao; Baba, Toshiaki; Tanaka, Makoto; Isomura, Masao; Tsuda, Shinya; Nakano, Shoichi; Kuwano, Yukinori [Sanyo Electric Co., Ltd., Hirakata, Osaka (Japan). Functional Materials Research Center

    1993-12-31

    Polycrystalline silicon (poly-Si) thin films prepared by the solid phase crystallization (SPC) method were studied for photovoltaic materials. To improve the properties of the poly-Si thin film, a-Si films suited to the solid phase crystallization were investigated. It was found that TA/TO (peak height ratio of TA peak and TO peak) in Raman spectra of a-Si films had the good correlation with the average grain size, and a factor for the enlargement of grain size was an increase of distortion energy stored in a-Si films. The first adoption of a textured substrate was also performed, which had effects on the enlargement of grain size in poly-Si thin films by the SPC method. By applying the a-Si films with large TA/TO value on textured substrate, the n-type poly-Si thin-film with the grain size of 6 {micro}m was fabricated and this film showed the Hall mobility of 623 cm{sup 2}/Vs (electron density: 3.0 {times} 10{sup 15} cm{sup {minus}3}). A new heterojunction technology, which was called Artificially Constructed Junction (ACJ), was developed by depositions of thin a-Si films on single-crystalline silicon (c-Si). In a solar cell using this technology, a high conversion efficiency of 18.7% was achieved. This is the highest value ever reported for solar cells in which the junctions were fabricated at a low temperature of less than 200 C. In a thin-film poly-Si solar cell (thickness: 10 {micro}m) applying this technology, a conversion efficiency of 6.3% was also obtained and a collection efficiency of 51% was achieved at a wavelength of 900 nm. This high value attributes to the hole diffusion length of 11 {micro}m, which is longer than the poly-Si thickness.

  6. Thin film Si solar cell fabricated at low temperature

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, K.; Yoshimi, M.; Tawada, Y.; Okamoto, Y.; Nakajima, A. [Central Research Laboratories, Kaneka Corporation, 2-80 Yoshida-cho, Hyogo-ku, Kobe (Japan)

    2000-05-01

    Research and development of our film Si solar cells are reviewed. Our developed film polycrystalline Si (poly-Si) cells are well described by the structure of natural surface texture and enhanced absorption with a back reflector (STAR), where the active poly-Si layer is fabricated by plasma chemical vapor deposition (CVD) at low temperature. The cell with a thickness of 2.0 {mu}m demonstrated an intrinsic efficiency of 10.7% (aperture 10.1%). By combining poly-Si cell with an a-Si cell, a stabilized efficiency of 12% has been reached for a-Si:H/poly-Si/poly-Si cell structure.

  7. Thin film solar cell configuration and fabrication method

    Science.gov (United States)

    Menezes, Shalini

    2009-07-14

    A new photovoltaic device configuration based on an n-copper indium selenide absorber and a p-type window is disclosed. A fabrication method to produce this device on flexible or rigid substrates is described that reduces the number of cell components, avoids hazardous materials, simplifies the process steps and hence the costs for high volume solar cell manufacturing.

  8. Advanced characterization techniques for thin film solar cells

    CERN Document Server

    Rau, Uwe; Kirchartz, Thomas

    2011-01-01

    Written by scientists from leading institutes in Germany, USA and Spain who use these techniques as the core of their scientific work and who have a precise idea of what is relevant for photovoltaic devices, this text contains concise and comprehensive lecture-like chapters on specific research methods.They focus on emerging, specialized techniques that are new to the field of photovoltaics yet have a proven relevance. However, since new methods need to be judged according to their implications for photovoltaic devices, a clear introductory chapter describes the basic physics of thin-film

  9. Sol-gel coatings for light trapping in crystalline thin film silicon solar cells

    OpenAIRE

    Brendel, R (Rolf); Gier, Andreas; Mennig, Martin; Schmidt, Helmut K.; J. H. Werner

    1997-01-01

    An increase of light absorption by light trapping is a key issue for the design of thin film solar cells from crystalline silicon. According to our numerical work, the deposition of crystalline silicon layers of thickness, W= 4 µm, on textured glass substrates doubles the cell current for facet angles, ? = 75°, and texture periods, p < 16 µm, without the need for anti reflection coatings. We demonstrate the fabrication of such micron-sized light traps by embossing of sol-gel...

  10. Porous copper zinc tin sulfide thin film as photocathode for double junction photoelectrochemical solar cells.

    Science.gov (United States)

    Dai, Pengcheng; Zhang, Guan; Chen, Yuncheng; Jiang, Hechun; Feng, Zhenyu; Lin, Zhaojun; Zhan, Jinhua

    2012-03-21

    Porous copper zinc tin sulfide (CZTS) thin film was prepared via a solvothermal approach. Compared with conventional dye-sensitized solar cells (DSSCs), double junction photoelectrochemical cells using dye-sensitized n-type TiO(2) (DS-TiO(2)) as the photoanode and porous p-type CZTS film as the photocathode shows an increased short circuit current, external quantum efficiency and power conversion efficiency. PMID:22322239

  11. Ion beam treatment of functional layers in thin-film silicon solar cells

    OpenAIRE

    Zhang, Wendi

    2012-01-01

    In silicon thin-film solar cells, transparent conductive layers have to fulfill the following requirements: high conductivity as effective contact, high transparency to transmit the light into the cell, and a textured surface which provides light scattering. Magnetron sputtered and wet-chemically textured aluminum doped zinc oxide (ZnO:Al) films are widely used as the transparent conductor. The technological goal of this dissertation is to develop an alternative to the wet etching process for...

  12. Development of a thin film solar cell interconnect for the PowerSphere concept

    International Nuclear Information System (INIS)

    Progressive development of microsatellite technologies has resulted in increased demand for lightweight electrical power subsystems including solar arrays. The use of thin film photovoltaics has been recognized as a key solution to meet the power needs. The lightweight cells can generate sufficient power and still meet critical mass requirements. Commercially available solar cells produced on lightweight substrates are being studied as an option to fulfill the power needs. The commercially available solar cells are relatively inexpensive and have a high payoff potential. Commercially available thin film solar cells are primarily being produced for terrestrial applications. The need to convert the solar cell from a terrestrial to a space compatible application is the primary challenge. Solar cell contacts, grids and interconnects need to be designed to be atomic oxygen resistant and withstand rapid thermal cycling environments. A mechanically robust solar cell interconnect is also required in order to withstand handling during fabrication and survive during launch. The need to produce the solar cell interconnects has been identified as a primary goal of the PowerSphere program and is the topic of this paper. Details of the trade study leading to the final design involving the solar cell wrap around contact, flex blanket, welding process, and frame will be presented at the conference

  13. Thin-Film Solar Cells on Metal Foil Substrates for Space Power

    Science.gov (United States)

    Raffaelle, Ryne P.; Hepp, Aloysius F.; Hoffman, David J.; Dhere, N.; Tuttle, J. R.; Jin, Michael H.

    2004-01-01

    Photovoltaic arrays have played a key role in power generation in space. The current technology will continue to evolve but is limited in the important mass specific power metric (MSP or power/weight ratio) because it is based on bulk crystal technology. The objective of this research is to continue development of an innovative photovoltaic technology for satellite power sources that could provide up to an order of magnitude saving in both weight and cost, and is inherently radiation-tolerant through use of thin film technology and thin foil substrates such as 5-mil thick stainless steel foil or 1-mil thick Ti. Current single crystal technology for space power can cost more than $300 per watt at the array level and weigh more than 1 kg/sq m equivalent to specific power of approx. 65 W/kg. Thin film material such as CuIn(1-x),Ga(x)S2, (CIGS2), CuIn(1-x), G(x)Se(2-y),S(y), (CIGSS) or amorphous hydrogenated silicon (a-Si:H) may be able to reduce both the cost and mass per unit area by an order of magnitude. Manufacturing costs for solar arrays are an important consideration for total spacecraft budget. For a medium sized 5kW satellite, for example, the array manufacturing cost alone may exceed $2 million. Moving to thin film technology could reduce this expense to less than $500 K. Previous work at FSEC demonstrated the potential of achieving higher efficiencies from CIGSS thin film solar cells on 5-mil thick stainless steel foil as well as initial stages of facility augmentation for depositing thin film solar cells on larger (6"x 4") substrates. This paper presents further progress in processing on metal foil substrates. Also, previous work at DayStar demonstrated the feasibility of flexible-thin-film copper-indium-gallium-diselenide (CIGS) solar cells with a power-to-weight ratio in excess of 1000 W/kg. We will comment on progress on the critical issue of scale-up of the solar cell absorber deposition process. Several important technical issues need to be resolved to realize the benefits of lightweight technologies for solar arrays, such as: monolithic interconnects, lightweight array structures, and new ultra-light support and deployment mechanisms. Once the technology has gained spaceflight certification it should find rapid acceptance in specific satellite markets.

  14. IR-imaging and non-destructive loss analysis on thin film solar modules and cells

    Science.gov (United States)

    Adams, Jens; Fecher, Frank W.; Hoga, Felix; Vetter, Andreas; Buerhop, Claudia; Brabec, Christoph J.

    2014-10-01

    CIGS thin film solar modules, despite their high efficiency, may contain three different kinds of macroscopic defects referred to as bulk defects, interface defects and interconnect defects. These occur due to the film's sensitivity to inhomogeneities during the manufacturing process and decreasing the electrical power output from a cell or module. In this study, we present infrared (IR) imaging and contactless loss analyses of defects contained in commercially manufactured thin film solar modules. We investigated different relations between the emitted IR-signal (using illuminated lock-in thermography ILIT) and the respective open circuit cell voltage (Voc) as well as the maximum power point (Pmpp). A simulation study, using the 2D finite element method (FEM), provides a deeper understanding as to the impact on electrical performance when defects are present on the cell or module.

  15. Ambiguities in optical simulations of nanotextured thin-film solar cells using the finite-element method.

    Science.gov (United States)

    Jäger, Klaus; Linssen, Dane N P; Isabella, Olindo; Zeman, Miro

    2015-09-21

    The optimal morphology of nanotextured interfaces, which increase the photocurrent density of thin-film solar cells, is still an open question. While random morphologies have the advantage to scatter light into a broad angular range, they are more difficult to assess with Maxwell solvers, such as the finite-element method (FEM). With this study we aim to identify necessary requirements on the unit cell design for the accurate simulation of nanotextured thin-film solar cells with FEM. PMID:26406736

  16. Cu(In1-xGax)Se2 based thin film solar cells

    CERN Document Server

    Kodigala, Subba Ramaiah

    2011-01-01

    This book provides valuable contents about the fabrication and characterization of chalcopyrite Cu(In1-xGax)Se2 based thin film solar cells and modules. The growth of chalcopyrite Cu(In1-xGax)(S1-ySey)2 absorbers, buffers, window layers, antireflection coatings, and finally metallic grids, which are the sole components of solar cells, is clearly illustrated. The absorber, which contains multiple elements, segregates secondary phases if the growth conditions are not well optimized i.e., the main drawback in the fabrication of solar cells. More importantly the solutions for the growth of thin f

  17. 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%.

  18. 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%.

  19. A study of ZnO:B films for thin film silicon solar cells

    Science.gov (United States)

    Yin, J.; Zhu, H.; Wang, Y.; Wang, Z.; Gao, J.; Mai, Y.; Ma, Y.; Wan, M.; Huang, Y.

    2012-10-01

    Boron doped zinc oxide (ZnO:B) films with different thicknesses were prepared with low pressure chemical vapor deposition (LPCVD) technique and implemented in thin film silicon solar cells as front and back electrodes. It is found that thick back ZnO:B film electrode in thin film silicon solar cells leads to a high fill factors (FF), which is attributed to an improvement of the electrical properties of the thick ZnO:B films, and in the meanwhile a slightly low short circuit currents (Jsc) due to a high light absorption in the thick back ZnO:B films. Differently, the thicker front ZnO:B film electrodes result in a high Jsc but a low FF of solar cells compared to the thinner ones. The low FF of the solar cells may be caused by the local shunt originated from the pinholes or by the cracks (zones of non-dense material) formed in particular in microcrystalline silicon materials deposited on rough front ZnO:B films. As to the high Jsc, it is expected to be due to a good light trapping effect inside solar cells grown on rough front ZnO:B films. Moreover, the application of high reflective polyvinyl butyral (PVB) foils effectively enhances the utilization of incident light in solar cells. By optimizing deposition process of the ZnO:B films, high efficiencies of 8.8% and 10% for single junction thin film amorphous silicon solar cells (a-Si:H, intrinsic layer thickness < 200 nm) and amorphous/microcrystalline silicon tandem solar cells (a-Si:H/?c-Si:H, intrinsic amorphous silicon layer thickness < 220 nm), respectively, are achieved.

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

    Energy Technology Data Exchange (ETDEWEB)

    Junghanns, Marcus; Plentz, Jonathan, E-mail: jonathan.plentz@ipht-jena.de; Andrä, Gudrun; Gawlik, Annett; Höger, Ingmar; Falk, Fritz [Leibniz Institute of Photonic Technology, Albert-Einstein-Str. 9, 07745 Jena (Germany)

    2015-02-23

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

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

    International Nuclear Information System (INIS)

    We fabricated an efficient hybrid solar cell by spin coating poly(3,4-ethylene-dioxythiophene):polystyrenesulfonate (PEDOT:PSS) on planar multicrystalline Si (mc-Si) thin films. The only 5??m thin Si absorber layers were prepared by diode laser crystallization of amorphous Si deposited by electron beam evaporation on glass. On these absorber layers, we studied the effect of SiOx and Al2O3 terminated Si surfaces. The short circuit density and power conversion efficiency (PCE) of the mc-Si/Al2O3/PEDOT:PSS solar cell increase from 20.6 to 25.4?mA/cm2 and from 7.3% to 10.3%, respectively, as compared to the mc-Si/SiOx/PEDOT:PSS cell. Al2O3 lowers the interface recombination and improves the adhesion of the polymer film on the hydrophobic mc-Si thin film. Open circuit voltages up to 604?mV were reached. This study demonstrates the highest PCE so far of a hybrid solar cell with a planar thin film Si absorber

  2. Bimodal nanostructured TiO2 thin films for dye sensitized solar cells.

    Czech Academy of Sciences Publication Activity Database

    Zukalová, Markéta; Kavan, Ladislav; Zukal, Arnošt; Graetzel, M.

    Málaga : BrownWalker Press, 2012. s. 99-99. ISBN 978-1-61233-558-2. [EMR 2012 : The Energy and Materials Research Conference. 20.06.2012-22.06.2012, Torremolinos] R&D Projects: GA ?R(CZ) GAP108/12/0814 Institutional support: RVO:61388955 Keywords : TiO2 * thin films * dye-sensitized solar cell Subject RIV: CG - Electrochemistry

  3. Scope of VHF Plasma Deposition for Thin-Film Silicon Solar Cells

    OpenAIRE

    Keppner, H.; Kroll, U.; TORRES, P.; J. Meier; Fischer, D.; Goetz, M; Tscharner, R.; Shah, A.

    1996-01-01

    The world-wide attempts in obtaining thin-film crystalline silicon are reviewed. Based on literature published so far, it appears that high-temperature manufacturing steps seem to be unavoidable for obtaining high conversion efficiencies of crystalline silicon based solar cells. High process temperatures are in contradiction for the use of low-cost substrates like e.g. glass or aluminium. Such substrates, however, are essential for obtaining low module manufacturing costs. The very high frequ...

  4. A New Approach to Light Scattering from Nanotextured Interfaces for Thin-Film Silicon Solar Cells

    OpenAIRE

    Battaglia, Corsin; Escarre Palou, Jordi; Söderström, Karin; Haug, Franz-Josef; Domine, Didier René; Feltrin, Andrea; Ballif, Christophe

    2010-01-01

    We investigate the influence of refractive index contrast on the light scattering properties of nanotextured interfaces, which serve as front contact for p-i-n thin-film silicon solar cells. We here focus on ZnO surfaces with randomly oriented pyramidal features, known for their excellent light trapping performance. Transparent replicas, with a different refractive index, but practically identical morphology compared to their ZnO masters, were fabricated via nanoimprinting. Within the theoret...

  5. Impact of contamination on hydrogenated amorphous silicon thin films & solar cells

    OpenAIRE

    Wördenweber, Jan

    2011-01-01

    This thesis deals with atmospheric contamination and cross-contamination of boron (single-chamber process) of the intrinsic absorber layer (i-layer) of p-i-n thin film solar cells based on hydrogenated amorphous silicon. The atmospheric contaminations were introduced by means of intentional leaks. Hereby, the focus is on the influence of contamination species (oxygen & nitrogen), quantity of contamination (leak flow), source of contamination (leaks at chamber wall or in the process gas pipe),...

  6. Admittance spectroscopy of Cu2ZnSnS4 based thin film solar cells

    OpenAIRE

    Fernandes, P.A.; Sartori, A. F.; Salomé, P. M. P.; Malaquias, J.; Cunha, A. F. da; Graça, M.P.F.; González, J. C.

    2012-01-01

    In this report, we propose an AC response equivalent circuit model to describe the admittance measurements of Cu2ZnSnS4 thin film solar cell grown by sulphurization of stacked metallic precursors. This circuit describes the contact resistances, the back contact, and the heterojunction with two trap levels. The study of the back contact resistance allowed the estimation of a back contact barrier of 246 meV. The analysis of the trap series with varying temperature revealed defect...

  7. Plasmon supported defect absorption in amorphous silicon thin film solar cells and devices

    OpenAIRE

    Lükermann, Florian

    2013-01-01

    In this thesis the influence of metallic nanoparticles on the absorption of hydrogenated amorphous silicon (a-Si:H) thin film solar cell devices is investigated. Small metal nanostructures with lateral dimensions well below 100 nm accompany strong absorption and large electric field amplitudes in their vicinity. This is caused by the localized surface plasmon (LSP) resonances that are excited upon interaction of light with the nanostructures. By combining silver nanoparticles (Ag NPs) with am...

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

    OpenAIRE

    Gabriel Onno; Kirner Simon; Klick Michael; Stannowski Bernd; Schlatmann Rutger

    2014-01-01

    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 ...

  9. In Situ Measuring System Designed for Improvement of Poly-Si Thin Film Solar Cells.

    Czech Academy of Sciences Publication Activity Database

    Pikna, Peter; Fejfar, Antonín; Ledinský, Martin; Vetushka, Aliaksi; Ko?ka, Jan; Benda, V.

    Honolulu, 2011. [The Fourth International Forum on Multidisciplinary Education and Research for Energy Science. 17.12.2011-21.12. 2011, Honolulu, Hawaii] R&D Projects: GA MŠk(CZ) LC06040; GA AV ?R KAN400100701; GA MŠk LC510 Grant ostatní: FP7(XE) 240826 Institutional research plan: CEZ:AV0Z10100521 Keywords : polycrystalline silicon * thin film solar cells * water vapor passivation Subject RIV: BM - Solid Matter Physics ; Magnetism

  10. Ultra-Thin-Film GaAs Solar Cells

    Science.gov (United States)

    Wang, K. L.; Shin, B. K.; Yeh, Y. C. M.; Stirn, R. J.

    1982-01-01

    Process based on organo-metallic chemical vapor deposition (OM/CVD) of trimethyl gallium with arsine forms economical ultrathin GaAs epitaxial films. Process has higher potential for low manufacturing cost and large-scale production compared with more-conventional halide CVD and liquid-phase epitaxy processes. By reducing thickness of GaAs and substituting low-cost substrate for single-crystal GaAs wafer, process would make GaAs solar cells commercially more attractive.

  11. Impurity-doped ZnO Thin Films Prepared by Physical Deposition Methods Appropriate for Transparent Electrode Applications in Thin-film Solar Cells

    Science.gov (United States)

    Minami, Tadatsugu; Miyata, Toshihiro; Nomoto, Jun-ichi

    2012-04-01

    This paper describes the development of transparent conducting impurity-doped ZnO thin films that would be appropriate for applications as transparent electrodes in thin-film solar cells. Transparent conducting Al-, B- and Ga-doped ZnO (AZO, BZO and GZO) thin films were prepared in a thickness range from 500 to 2000 nm on glass substrates at 200°C using various physical deposition methods: BZO films with vacuum arc plasma evaporation, AZO and GZO films with different types of magnetron sputtering depositions (MSDs) and all films with pulsed laser deposition (PLD). The suitability and stability of the electrical properties and, in addition, the suitability of the light scattering characteristics and surface texture formation were investigated in the prepared thin films. In particular, the suitability and stability evaluation was focused on the use of AZO, BZO and GZO thin films prepared by doping each impurity at an appropriate content to attain the lowest resistivity. The higher Hall mobility obtained in impurity-doped ZnO thin films with a resistivity on the order of 10-4 ?cm was related more to the content, i.e., the obtained carrier concentration, rather than the kind of impurity doped into the films. The stability of resistivity of the BZO thin films in long-term moisture-resistance tests (in air at 85% relative humidity and 85°C) was found to be lower than that of the AZO and GZO thin films. The surface texture formation was carried out by wet-chemical etching (in a 0.1% HCl solution at 25°C) conducted either before or after being heat-treated either with rapid thermal annealing (RTA) or without RTA. The suitability of the light scattering characteristics and the surface texture formation obtainable by wet-chemical etching (for use in transparent electrode applications) was considerably dependent on the deposition method used as well as whether the wet-chemical etching was conducted with or without RTA. A significant improvement of both transmittance and haze value at wavelengths up to about 1200 nm in the near-infrared region was attained in surface-textured AZO films that were prepared by r.f. power superimposed d.c. MSD as well as etched after being heat treated with RTA at 500°C for 5 min in air. The obtained suitability and stability in impurity-doped ZnO thin films were related more to the content rather than the kind of impurity doped into the films as well as to the deposition method used.

  12. Full potential of radial junction Si thin film solar cells with advanced junction materials and design

    Science.gov (United States)

    Qian, Shengyi; Misra, Soumyadeep; Lu, Jiawen; Yu, Zhongwei; Yu, Linwei; Xu, Jun; Wang, Junzhuan; Xu, Ling; Shi, Yi; Chen, Kunji; Roca i Cabarrocas, Pere

    2015-07-01

    Combining advanced materials and junction design in nanowire-based thin film solar cells requires a different thinking of the optimization strategy, which is critical to fulfill the potential of nano-structured photovoltaics. Based on a comprehensive knowledge of the junction materials involved in the multilayer stack, we demonstrate here, in both experimental and theoretical manners, the potential of hydrogenated amorphous Si (a-Si:H) thin film solar cells in a radial junction (RJ) configuration. Resting upon a solid experimental basis, we also assess a more advanced tandem RJ structure with radially stacking a-Si:H/nanocrystalline Si (nc-Si:H) PIN junctions, and show that a balanced photo-current generation with a short circuit current density of Jsc = 14.2 mA/cm2 can be achieved in a tandem RJ cell, while reducing the expensive nc-Si:H absorber thickness from 1-3 ? m (in planar tandem cells) to only 120 nm. These results provide a clearly charted route towards a high performance Si thin film photovoltaics.

  13. Microscopic characterizations of nanostructured silicon thin films for solar cells.

    Czech Academy of Sciences Publication Activity Database

    Fejfar, Antonín; Klapetek, P.; Zlámal, J.; Vetushka, Aliaksi; Ledinský, Martin; Ko?ka, Jan

    Warrendale : MRS, 2011 - (Yan, B.; Higashi, S.; Tsai, C.; Wang, Q.; Gleskova, H.), s. 313-321 ISBN 9781605112985. - (MRS Symposium Proceeding. 1321). [Materials Research Society Spring Meeting. San Francisko (US), 25.04.2011-29.04.2011] R&D Projects: GA MŠk(CZ) LC06040; GA MŠk(CZ) MEB061012; GA AV ?R KAN400100701; GA MŠk LC510 Grant ostatní: 7. Framework programme EU(XE) no. 240826 Institutional research plan: CEZ:AV0Z10100521 Keywords : silicon * scanning probe methods * solar cells Subject RIV: BM - Solid Matter Physics ; Magnetism

  14. Experimental study of Cu2ZnSnS4 thin films for solar cells

    OpenAIRE

    Flammersberger, Hendrik

    2010-01-01

    Cu2ZnSnS4 (CZTS) is a semiconductor with a direct band gap of about 1,5 eV and anabsorption coefficient of 10^4 cm^-1, and is for this reason a potential thin film solarcell material. Demonstrated efficiencies of up to 6,8% as well as use of cheap andabundant elements make CZTS a promising alternative to current solar cells.The aim of this study was to fabricate and characterize CZTS films and to evaluatetheir performance in complete solar cells. For the fabrication of CZTS we applied atwo-st...

  15. Spectral analysis of the angular distribution function of back reflectors for thin film silicon solar cells

    OpenAIRE

    Escarré i Palou, Jordi; Villar, Fernando; Asensi López, José Miguel; Bertomeu i Balagueró, Joan; Andreu i Batallé, Jordi

    2006-01-01

    Nowadays, one of the most important challenges to enhance the efficiency of thin film silicon solar cells is to increase the short circuit intensity by means of optical confinement methods, such as textured back-reflector structures. In this work, two possible textured structures to be used as back reflectors for n-i-p solar cells have been optically analyzed and compared to a smooth one by using a system which is able to measure the angular distribution function (ADF) of the scattered light ...

  16. Role of 2-D periodic symmetrical nanostructures in improving efficiency of thin film solar cells

    Science.gov (United States)

    Zhang, Wei; Jiang, Liyong; Li, Xiangyin

    2016-01-01

    We systematically investigated several different nanostructures in crystalline silicon (c-Si) thin film solar cells and then proposed a brand-new structure with two dimensional (2-D) periodic dielectric cylinders on the top and annular metal columns on bottom surface to enhance the optical harvesting. The periodic symmetrical nanostructures affect the solar cell efficiency due to the grating diffraction effect of dielectric columns and surface plasmon polaritons (SPPs) effect induced by metal nanostructures at the dielectric-metal interface. About 52.1% more optical absorption and 33.3% more power conversion efficiency are obtained, and the maximum short current reaches to 33.24 mA/cm2.

  17. Needle Profile Grating Structure for Absorption Enhancement in GaAs Thin Film Solar Cells

    Science.gov (United States)

    Wang, Yile; Zhang, Xu; Guo, Minqiang; Sun, Xiaohong; Yu, Yanguang; Xi, Jiangtao

    2015-11-01

    We conduct a systematic study of thin film solar cells consisting of a GaAs needle profile (NP) grating structure as a light-trapping layer. The influence of geometric parameters on the optical absorption of the NP grating is investigated using rigorous coupled wave analysis and the finite element method. This type of structure can lead to broadband optical absorption enhancement throughout the wavelength range that we studied. Our simulation results reveal that the absorption efficiency of NP grating can be improved significantly compared with its rectangular grating counterpart. The proposed structure is expected to illuminate the design and fabrication of high-efficiency solar cells.

  18. 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.

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

    Science.gov (United States)

    Gabriel, Onno; Kirner, Simon; Klick, Michael; Stannowski, Bernd; Schlatmann, Rutger

    2014-02-01

    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.

  20. Identification of critical stacking faults in thin-film CdTe solar cells

    Science.gov (United States)

    Yoo, Su-Hyun; Butler, Keith T.; Soon, Aloysius; Abbas, Ali; Walls, John M.; Walsh, Aron

    2014-08-01

    Cadmium telluride (CdTe) is a p-type semiconductor used in thin-film solar cells. To achieve high light-to-electricity conversion, annealing in the presence of CdCl2 is essential, but the underlying mechanism is still under debate. Recent evidence suggests that a reduction in the high density of stacking faults in the CdTe grains is a key process that occurs during the chemical treatment. A range of stacking faults, including intrinsic, extrinsic, and twin boundary, are computationally investigated to identify the extended defects that limit performance. The low-energy faults are found to be electrically benign, while a number of higher energy faults, consistent with atomic-resolution micrographs, are predicted to be hole traps with fluctuations in the local electrostatic potential. It is expected that stacking faults will also be important for other thin-film photovoltaic technologies.

  1. Identification of critical stacking faults in thin-film CdTe solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Su-Hyun; Walsh, Aron, E-mail: a.walsh@bath.ac.uk [Global E3 Institute, Department of Materials Science and Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of); Centre for Sustainable Chemical Technologies and Department of Chemistry, University of Bath, Bath BA2 7AY (United Kingdom); Butler, Keith T. [Centre for Sustainable Chemical Technologies and Department of Chemistry, University of Bath, Bath BA2 7AY (United Kingdom); Soon, Aloysius [Global E3 Institute, Department of Materials Science and Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of); Abbas, Ali; Walls, John M., E-mail: j.m.wall@loughborough.ac.uk [Centre for Renewable Energy Systems Technology, School of Electronic, Electrical and Systems Engineering, Loughborough University, Leicestershire LE11 3TU (United Kingdom)

    2014-08-11

    Cadmium telluride (CdTe) is a p-type semiconductor used in thin-film solar cells. To achieve high light-to-electricity conversion, annealing in the presence of CdCl{sub 2} is essential, but the underlying mechanism is still under debate. Recent evidence suggests that a reduction in the high density of stacking faults in the CdTe grains is a key process that occurs during the chemical treatment. A range of stacking faults, including intrinsic, extrinsic, and twin boundary, are computationally investigated to identify the extended defects that limit performance. The low-energy faults are found to be electrically benign, while a number of higher energy faults, consistent with atomic-resolution micrographs, are predicted to be hole traps with fluctuations in the local electrostatic potential. It is expected that stacking faults will also be important for other thin-film photovoltaic technologies.

  2. Polycrystalline Silicon Thin Film for Solar Cells Utilizing Aluminum Induced Crystallization Method

    Science.gov (United States)

    Ishikawa, Yasuaki; Nakamura, Atsushi; Uraoka, Yukiharu; Fuyuki, Takashi

    2004-03-01

    In order to realize a polycrystalline silicon (poly-Si) thin film solar cell with low cost and high efficiency, high-quality poly-Si is indispensable. We fabricated a high-quality poly-Si film by using aluminum induced crystallization (AIC) as a method of crystallizing amorphous silicon. AIC is a method of crystallizing amorphous silicon by heat treatment below the eutectic temperature (577°C). Using AIC poly-Si film as the seeding layer and atmospheric pressure chemical vapor deposition (APCVD), continuous columnar poly-Si with large grain size was achieved. Deposition of the poly-Si thin film onto AIC poly-Si films was carried out using APCVD. Crystallinity and electronic property of the deposited films was evaluated. Comparably high Hall mobility of more than 80 cm2/Vs was successfully obtained.

  3. Sustainability of photovoltaics. The case for thin-film solar cells

    International Nuclear Information System (INIS)

    To ensure photovoltaics become a major sustainable player in a competitive power-generation market, they must provide abundant, affordable electricity, with environmental impacts drastically lower than those from conventional power generation. The recent reduction in the cost of 2nd generation thin-film PV is remarkable, meeting the production milestone of $1 per watt in the fourth quarter of 2008. This achievement holds great promise for the future. However, the questions remaining are whether the expense of PV modules can be lowered further, and if there are resource- and environmental-impact constraints to growth. I examine the potential of thin-films in a prospective life-cycle analysis, focusing on direct costs, resource availability, and environmental impacts. These three aspects are closely related; developing thinner solar cells and recycling spent modules will become increasingly important in resolving cost, resource, and environmental constraints to large scales of sustainable growth. (author)

  4. Identification of critical stacking faults in thin-film CdTe solar cells

    International Nuclear Information System (INIS)

    Cadmium telluride (CdTe) is a p-type semiconductor used in thin-film solar cells. To achieve high light-to-electricity conversion, annealing in the presence of CdCl2 is essential, but the underlying mechanism is still under debate. Recent evidence suggests that a reduction in the high density of stacking faults in the CdTe grains is a key process that occurs during the chemical treatment. A range of stacking faults, including intrinsic, extrinsic, and twin boundary, are computationally investigated to identify the extended defects that limit performance. The low-energy faults are found to be electrically benign, while a number of higher energy faults, consistent with atomic-resolution micrographs, are predicted to be hole traps with fluctuations in the local electrostatic potential. It is expected that stacking faults will also be important for other thin-film photovoltaic technologies

  5. CIGS2 Thin-Film Solar Cells on Flexible Foils for Space Power

    Science.gov (United States)

    Dhere, Neelkanth G.; Ghongadi, Shantinath R.; Pandit, Mandar B.; Jahagirdar, Anant H.; Scheiman, David

    2002-01-01

    CuIn(1-x)Ga(x)S2 (CIGS2) thin-film solar cells are of interest for space power applications because of the near optimum bandgap for AM0 solar radiation in space. CIGS2 thin film solar cells on flexible stainless steel (SS) may be able to increase the specific power by an order of magnitude from the current level of 65 Wkg(sup -1). CIGS solar cells are superior to the conventional silicon and gallium arsenide solar cells in the space radiation environment. This paper presents research efforts for the development of CIGS2 thin-film solar cells on 127 micrometers and 20 micrometers thick, bright-annealed flexible SS foil for space power. A large-area, dual-chamber, inline thin film deposition system has been fabricated. The system is expected to provide thickness uniformity of plus or minus 2% over the central 5" width and plus or minus 3% over the central 6" width. During the next phase, facilities for processing larger cells will be acquired for selenization and sulfurization of metallic precursors and for heterojunction CdS layer deposition both on large area. Small area CIGS2 thin film solar cells are being prepared routinely. Cu-rich Cu-Ga/In layers were sputter-deposited on unheated Mo-coated SS foils from CuGa (22%) and In targets. Well-adherent, large-grain Cu-rich CIGS2 films were obtained by sulfurization in a Ar: H2S 1:0.04 mixture and argon flow rate of 650 sccm, at the maximum temperature of 475 C for 60 minutes with intermediate 30 minutes annealing step at 120 C. Samples were annealed at 500 C for 10 minutes without H2S gas flow. The intermediate 30 minutes annealing step at 120 C was changed to 135 C. p-type CIGS2 thin films were obtained by etching the Cu-rich layer segregated at the surface using dilute KCN solution. Solar cells were completed by deposition of CdS heterojunction partner layer by chemical bath deposition, transparent-conducting ZnO/ZnO: Al window bilayer by RF sputtering, and vacuum deposition of Ni/Al contact fingers through metal mask. PV parameters of a CIGS2 solar cell on 127 micrometers thick SS flexible foil measured under AM 0 conditions at NASA GRC were: V(sub oc) = 802.9 mV, J(sub sc) = 25.07 mA per square centimeters, FF = 60.06%, and efficiency 0 = 8.84%. For this cell, AM 1.5 PV parameters measured at NREL were: V(sub oc) = 788 mV, J(sub sc) = 19.78 mA per square centimeter, FF = 59.44%, efficiency 0 = 9.26%. Quantum efficiency curve showed a sharp QE cutoff equivalent to CIGS2 bandgap of approximately 1.50 eV, fairly close to the optimum value for efficient AM0 PV conversion in the space.

  6. Synthesis of Cu2ZnSnS4 thin films by a precursor solution paste for thin film solar cell applications.

    Science.gov (United States)

    Cho, Jin Woo; Ismail, Agus; Park, Se Jin; Kim, Woong; Yoon, Sungho; Min, Byoung Koun

    2013-05-22

    Cu2ZnSnS4 (CZTS) is a very promising semiconductor material when used for the absorber layer of thin film solar cells because it consists of only abundant and inexpensive elements. In addition, a low-cost solution process is applicable to the preparation of CZTS absorber films, which reduces the cost when this film is used for the production of thin film solar cells. To fabricate solution-processed CZTS thin film using an easily scalable and relatively safe method, we suggest a precursor solution paste coating method with a two-step heating process (oxidation and sulfurization). The synthesized CZTS film was observed to be composed of grains of a size of ~300 nm, showing an overall densely packed morphology with some pores and voids. A solar cell device with this film as an absorber layer showed the highest efficiency of 3.02% with an open circuit voltage of 556 mV, a short current density of 13.5 mA/cm(2), and a fill factor of 40.3%. We also noted the existence of Cd moieties and an inhomogeneous Zn distribution in the CZTS film, which may have been triggered by the presence of pores and voids in the CZTS film. PMID:23611655

  7. Absorption Enhancement of Thin-film Solar Cell with Rectangular Ag Nanoparticles

    Directory of Open Access Journals (Sweden)

    Zongheng Yuan

    2014-01-01

    Full Text Available Solar power has gained a great deal of attention as a clean energy source with the potential to replace fossil fuel. Researchers have focused in increasing the efficiency of thin film solar cells. In this study, rectangular Ag nanoparticles were placed on the silicon layer of a silicon solar cell. The absorption enhancement of the silicon was systematically investigated via the Finite Difference Time Domain Method (FDTD. The improvement in silicon absorption of the solar cell because of the addition of Ag nanoparticles was studied by calculating the enhancement factor by using the Lumerical FDTD solutions simulation package. The results demonstrated that the light absorption was significantly improved because of the localized surface plasmon resonance of the Ag nanoparticles. The structure with rectangular Ag nanoparticles obtained the most efficient absorption enhancement compared with the sphere and cylinder Ag nanoparticles. The effects of nanoparticle parameters on the absorption enhancement were also thoroughly analyzed. The optimal absorption enhancement was achieved by adjusting the parameters of nanoparticles. The structure may be used to develop highly efficient thin film solar cells.

  8. Five roads towards increased optical absorption and high stable efficiency for thin film silicon solar cells.

    Czech Academy of Sciences Publication Activity Database

    Van??ek, Milan; Poruba, Aleš; Remeš, Zden?k; Holovský, Jakub; Purkrt, Adam; Babchenko, Oleg; Hruška, Karel; Meier, J.; Kroll, U.

    Munich : WIP-Renewable Energies, 2009 - (Sinke, W.; Ossenbrink, H.; Helm, P.), 2286-2289 ISBN 3-936338-25-6. [European Photovoltaic Solar Energy Conference /24./. Hamburg (DE), 21.09.2009-25.09.2009] R&D Projects: GA MŠk(CZ) 7E09057 Grant ostatní: 7th FP EU N2P(XE) CP-IP 214134-2; 6FP EU ATHLET(XE) 019670 (SES6) Institutional research plan: CEZ:AV0Z10100521 Keywords : thin film silicon solar cells * amorphous silicon * nanostructure * high stable efficiency Subject RIV: BM - Solid Matter Physics ; Magnetism

  9. Effects of potassium doping on solution processed kesterite Cu2ZnSnS4 thin film solar cells

    Science.gov (United States)

    Tong, Zhengfu; Yan, Chang; Su, Zhenghua; Zeng, Fangqin; Yang, Jia; Li, Yi; Jiang, Liangxing; Lai, Yanqing; Liu, Fangyang

    2014-12-01

    Alkaline metals doping is one of the approaches for achieving high efficiency Cu(In,Ga)Se2 (CIGS) solar cell. Recently, potassium doping helps to break the record efficiency of CIGS solar cell doped with sodium. In this paper, we have investigated how incorporation of potassium can influence the properties of Cu2ZnSnS4 (CZTS) thin film and the performance of resulting solar cell. Our results showed that K doping can enhance the (112) preferred orientation, increase the grain size and reduce the second phase ZnS of the CZTS thin films. After K doping, despite of some drop of Voc for CZTS thin film solar cells, the Rs is decreased and the Jsc is improved markedly, and the solar cell efficiency is boosted.

  10. Growth, etching, and stability of sputtered ZnO:Al for thin-film silicon solar cells

    OpenAIRE

    Owen, Jorj Ian

    2011-01-01

    Aluminum doped zinc oxide (ZnO:Al) can fulfill many requirements in thin film solar cells, acting as (1) a transparent contact through which the incident light is transmitted, (2) part of the back reflector, and (3) a source of light scattering. Magnetron sputtered ZnO:Al thin films are highly transparent, conductive, and are typically texturized by post deposition etching in a dilute hydrochloric acid (HCl) solution to achieve light scattering. The ZnO:Al thin film electronic and optical pro...

  11. Thin Film intermediate band chalcopyrite solar cells: Theoretical Analysis of device performance and prospects for their realisation

    OpenAIRE

    Fuertes Marrón, David; Martí Vega, Antonio; Tablero Crespo, César; Antolín Fernández, Elisa; Cánovas Díaz, Enrique; García-Linares Fontes, Pablo; Luque López, Antonio

    2009-01-01

    The feasibility of implementing the intermediate-band (IB) concept into a relevant thin-film technology has been assessed. Compounds belonging to the group of I-III-VI2 chalcopyrites, currently used as absorbers in the leading thin-film technology, appear as promising candidates for the realization of IB-devices. In this paper we first analyze the expected performance of such a thin-film intermediate band solar cell (TF-IBSC) by considering different levels of idealization. In the second...

  12. Nano imprint lithography of textures for light trapping in thin film silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Soppe, W.J.; Dorenkamper, M.S.; Notta, J.B.; Pex, P.P.A.C. [ECN-Solliance, High Tech Campus 5, 5656 AE Eindhoven (Netherlands); Schipper, W.; Wilde, R. [Nanoptics GmbH, Innungsstrasse 5, 21244 Buchholz (Germany)

    2012-09-15

    Nano Imprint Lithography (NIL) is a versatile and commercially viable technology for fabrication of structures for light trapping in solar cells. We demonstrate the applicability of NIL in thin film silicon solar cells in substrate configuration, where NIL is used to fabricate a textured rear contact of the solar cells. We applied random structures, based on the natural texture of SnO:F grown by APCVD, and designed 2D periodic structures and show that for single junction {mu}c-Si cells these textured rear contacts lead to an increase of Jsc of more than 40 % in comparison to cells with flat rear contacts. Cells on optimized periodic textures showed higher fill factors which can be attributed to reduced microcrack formation, leading to less shunting in comparison to cells on random textures.

  13. Comparison between periodic and stochastic parabolic light trapping structures for thin-film microcrystalline silicon solar cells

    OpenAIRE

    Peters, M.; Battaglia, C.; Forberich, K.; Blaesi, B.; Sahraei, N.; Aberle, A. G.

    2012-01-01

    Light trapping is of very high importance for silicon photovoltaics (PV) and especially for thin-film silicon solar cells. In this paper we investigate and compare theoretically the light trapping properties of periodic and stochastic structures having similar geometrical features. The theoretical investigations are based on the actual surface geometry of a scattering structure, characterized by an atomic force microscope. This structure is used for light trapping in thin-film microcrystallin...

  14. Effects of RF power and pressure on performance of HF-PECVD silicon thin-film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Lien, Shui-Yang, E-mail: syl@mdu.edu.t [Department of Materials Science and Engineering, MingDao University, ChungHua 52345, Taiwan (China); Wang, Chao-Chun [Department of Materials Science and Engineering, Nation Chung Hsing University, Taichung 402, Taiwan (China); Shen, Chau-Te; Ou, Yu-Chih; Cho, Yun-Shao; Weng, Ko-Wei; Chao, Ching-Hsun; Chen, Chia-Fu; Wuu, Dong-Sing [Department of Materials Science and Engineering, MingDao University, ChungHua 52345, Taiwan (China)

    2010-10-01

    High-frequency plasma-enhanced chemical vapor deposition (HF-PECVD) is a widely applicable method of deposition over a large area at a high rate for fabricating silicon thin-film solar cells. This investigation presents the properties of hydrogenated amorphous silicon (a-Si:H) films and the preparation of highly-efficient p-i-n solar cells using an RF (27.1 MHz) excitation frequency. The influence of the power (10-40 W) and pressure (20-50 Pa) used during the deposition of absorber layers in p-i-n solar cells on the properties and mechanism of growth of the a-Si:H thin films and the solar cells is studied. The a-Si:H thin films prepared under various deposition conditions have widely varying deposition rates, optical-electronic properties and microstructures. When the deposition parameters were optimized, amorphous silicon-based thin-film silicon solar cells with efficiency of 7.6% were fabricated by HF-PECVD. These results are very encouraging for the future fabrication of highly-efficient thin-film solar cells by HF-PECVD.

  15. Effects of RF power and pressure on performance of HF-PECVD silicon thin-film solar cells

    International Nuclear Information System (INIS)

    High-frequency plasma-enhanced chemical vapor deposition (HF-PECVD) is a widely applicable method of deposition over a large area at a high rate for fabricating silicon thin-film solar cells. This investigation presents the properties of hydrogenated amorphous silicon (a-Si:H) films and the preparation of highly-efficient p-i-n solar cells using an RF (27.1 MHz) excitation frequency. The influence of the power (10-40 W) and pressure (20-50 Pa) used during the deposition of absorber layers in p-i-n solar cells on the properties and mechanism of growth of the a-Si:H thin films and the solar cells is studied. The a-Si:H thin films prepared under various deposition conditions have widely varying deposition rates, optical-electronic properties and microstructures. When the deposition parameters were optimized, amorphous silicon-based thin-film silicon solar cells with efficiency of 7.6% were fabricated by HF-PECVD. These results are very encouraging for the future fabrication of highly-efficient thin-film solar cells by HF-PECVD.

  16. CdTe Thin Film Solar Cells: Present Status and Future Perspectives

    Science.gov (United States)

    Romeo, Alessandro

    2011-10-01

    The CdTe thin film solar cells have reached enough technological maturity to be one of the most successful photovoltaic technologies in the market. From the early stage of research, in the eighties, up to now, CdTe solar cells have provided a constant increase in efficiency together with a more effective fabrication process that reduces the amount of material and increases the industrial scalability, due to the large variety of the fabrication processes and to the robustness of the material.In the last 10 years, different key issues from the recrystallization/activation treatment (enhancing CdTe grain size and passivating the grain boundaries) to the back contact stability (incapsulating copper into a stable compound) have been deeply studied and engineered. With these advances the CdTe photovoltaic technology has now the lowest cost per Watt available, due to the low amount of material involved, the low energies used in the fabrication process and the fast all-in-line production with monolithical integration of the solar cells. In this paper, recent technologies for CdTe thin film solar cell fabrication are shown, low temperature and high temperature deposition processes in the laboratory and on the industrial scale, together with the monolithical integration, together with some environmental considerations are described.

  17. Fabrication of solution processed 3D nanostructured CuInGaS? 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 CuInGaS? (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 ?m. 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. PMID:24569126

  18. Sol-gel coatings for light trapping in crystalline thin film silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Brendel, R. [Max-Planck-Institut fuer Festkoerperforschung, Stuttgart (Germany); Gier, A.; Mennig, M.; Schmidt, H. [Institut fuer Neue Materialien GmbH, Saarbruecken (Germany); Werner, J.H. [Institut fuer Physikalische Elektronik, Universitaet Stuttgart, Stuttgart (Germany)

    1997-09-01

    An increase of light absorption by light trapping is a key issue for the design of thin film solar cells from crystalline silicon. According to our numerical work, the deposition of crystalline silicon layers of thickness, W=4 {mu}m, on textured glass substrates doubles the cell current for facet angles, {alpha}=75, and texture periods, p<16 {mu}m, without the need for anti reflection coatings. We demonstrate the fabrication of such micron-sized light traps by embossing of sol-gel glasses

  19. Nanotextured thin film silicon solar cells:optical model.

    Czech Academy of Sciences Publication Activity Database

    Špringer, Ji?í; Poruba, Aleš; Fejfar, Antonín; Van??ek, Milan; Feitknecht, L.; Wyrsch, N.; Meier, J.; Shah, A.

    London : James & James, 2000 - (Scheer, H.; McNelis, B.; Palz, W.; Ossenbrink, H.; Helm, P.), s. 434-437 ISBN 1-902916-18-2. [European Photovoltaic Solar Energy Conference /16./. Glasgow (GB), 01.05.2000-05.05.2000] Institutional research plan: CEZ:AV0Z1010914 Keywords : si-films * modeling * texturization Subject RIV: BM - Solid Matter Physics ; Magnetism

  20. Sputtered CdTe thin film solar cells with Cu2Te/Au back contact

    International Nuclear Information System (INIS)

    In this work, Cu2Te/Au back contact for CdTe thin film solar cells were prepared by vacuum evaporation. Influence of annealing temperature on the structure and electrical properties of Cu2Te films were investigated by field emission scanning electron microscope, X-ray diffraction, and Hall effect measurement. Also, CdS/CdTe thin film solar cells were fabricated by magnetron sputtering process, which is favorable for large area deposition and mass production, and the photovoltaic characteristics were studied. As the annealing temperature was increased, the crystal structure transformed from Cu2Te for as-deposited film to Cu2?xTe hexagonal phase, and the grains in the film became bigger. The electrical resistivity was slightly higher by the annealing. The cell efficiency was significantly improved by the heat treatment, and showed a maximum value of 9.14% at 180 °C. From these results, Cu2Te/Au contact acts as the proper pseudo-ohmic contact onto CdTe film. However, further increase of annealing temperature caused the deterioration of cell performance. - Highlights: • Annealing effects of the vacuum evaporated Cu2Te films were investigated. • The transformation from Cu2Te to Cu2?xTe hexagonal phase occurred by annealing. • The performance of the solar cell was highly increased by annealing at 180 °C. • Cu2Te/Au contact acts as the proper pseudo-ohmic contact onto CdTe film

  1. A study of ZnO:B films for thin film silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Yin, J.; Zhu, H.; Wang, Y.; Wang, Z.; Gao, J.; Mai, Y.; Ma, Y. [Baoding Tianwei Solarfilms Co., Ltd., 071051, Baoding (China); Wan, M. [Department of Chemistry and Material science, Hunan Institute of Humanities, Science and Technology, 417000, Loudi (China); Huang, Y., E-mail: y.huang@btw-solarfilms.com [Baoding Tianwei Solarfilms Co., Ltd., 071051, Baoding (China)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer ZnO:B films with different thicknesses were prepared with LPCVD technique. Black-Right-Pointing-Pointer The thicker ZnO:B back electrodes lead to higher FF but slightly lower J{sub sc.} Black-Right-Pointing-Pointer Back polyvinyl butyral (PVB) foils improves the utilization of incident light in solar cells. Black-Right-Pointing-Pointer The thicker ZnO:B front electrode films result in high J{sub sc} but lower FF. - Abstract: Boron doped zinc oxide (ZnO:B) films with different thicknesses were prepared with low pressure chemical vapor deposition (LPCVD) technique and implemented in thin film silicon solar cells as front and back electrodes. It is found that thick back ZnO:B film electrode in thin film silicon solar cells leads to a high fill factors (FF), which is attributed to an improvement of the electrical properties of the thick ZnO:B films, and in the meanwhile a slightly low short circuit currents (J{sub sc}) due to a high light absorption in the thick back ZnO:B films. Differently, the thicker front ZnO:B film electrodes result in a high J{sub sc} but a low FF of solar cells compared to the thinner ones. The low FF of the solar cells may be caused by the local shunt originated from the pinholes or by the cracks (zones of non-dense material) formed in particular in microcrystalline silicon materials deposited on rough front ZnO:B films. As to the high J{sub sc}, it is expected to be due to a good light trapping effect inside solar cells grown on rough front ZnO:B films. Moreover, the application of high reflective polyvinyl butyral (PVB) foils effectively enhances the utilization of incident light in solar cells. By optimizing deposition process of the ZnO:B films, high efficiencies of 8.8% and 10% for single junction thin film amorphous silicon solar cells (a-Si:H, intrinsic layer thickness < 200 nm) and amorphous/microcrystalline silicon tandem solar cells (a-Si:H/{mu}c-Si:H, intrinsic amorphous silicon layer thickness < 220 nm), respectively, are achieved.

  2. A study of ZnO:B films for thin film silicon solar cells

    International Nuclear Information System (INIS)

    Highlights: ? ZnO:B films with different thicknesses were prepared with LPCVD technique. ? The thicker ZnO:B back electrodes lead to higher FF but slightly lower Jsc. ? Back polyvinyl butyral (PVB) foils improves the utilization of incident light in solar cells. ? The thicker ZnO:B front electrode films result in high Jsc but lower FF. - Abstract: Boron doped zinc oxide (ZnO:B) films with different thicknesses were prepared with low pressure chemical vapor deposition (LPCVD) technique and implemented in thin film silicon solar cells as front and back electrodes. It is found that thick back ZnO:B film electrode in thin film silicon solar cells leads to a high fill factors (FF), which is attributed to an improvement of the electrical properties of the thick ZnO:B films, and in the meanwhile a slightly low short circuit currents (Jsc) due to a high light absorption in the thick back ZnO:B films. Differently, the thicker front ZnO:B film electrodes result in a high Jsc but a low FF of solar cells compared to the thinner ones. The low FF of the solar cells may be caused by the local shunt originated from the pinholes or by the cracks (zones of non-dense material) formed in particular in microcrystalline silicon materials deposited on rough front ZnO:B films. As to the high Jsc, it is expected to be due to a good light trapping effect inside solar cells grown on rough front ZnO:B films. Moreover, the application of high reflective polyvinyl butyral (PVB) foils effectively enhances the utilization of incident light in solar cells. By optimizing deposition process of the ZnO:B films, high efficiencies of 8.8% and 10% for single junction thin film amorphous silicon solar cells (a-Si:H, intrinsic layer thickness < 200 nm) and amorphous/microcrystalline silicon tandem solar cells (a-Si:H/?c-Si:H, intrinsic amorphous silicon layer thickness < 220 nm), respectively, are achieved.

  3. Defect annealing processes for polycrystalline silicon thin-film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Steffens, S., E-mail: simon.steffens@helmholtz-berlin.de [Helmholtz-Zentrum Berlin, Berlin (Germany); Becker, C. [Helmholtz-Zentrum Berlin, Berlin (Germany); Zollondz, J.-H., E-mail: hzollondz@masdarpv.com [CSG Solar AG, Thalheim (Germany); Chowdhury, A.; Slaoui, A. [L’Institut d’Électronique du Solide et des Systèmes, Strasbourg (France); Lindekugel, S. [Fraunhofer-Institut für Solare Energiesysteme, Freiburg (Germany); Schubert, U.; Evans, R. [Suntech R and D Australia Pty Ltd, Sydney (Australia); Rech, B. [Helmholtz-Zentrum Berlin, Berlin (Germany)

    2013-05-15

    Highlights: ? Defect annealing processes were applied to polycrystalline silicon thin films. ? Conventional rapid thermal annealing was compared to novel annealing processes using a laser system and a zone-melting recrystallization setup. ? The open circuit voltages could be enhanced from below 170 mV up to 482 mV. ? Increase in Sun's-V{sub OC} values with decrease in FWHM of the TO Raman phonon of crystalline silicon. ? Solar cells were fabricated for I–V-measurements: Best solar cell efficiency of 6.7%. -- Abstract: A variety of defect healing methods was analyzed for optimization of polycrystalline silicon (poly-Si) thin-film solar cells on glass. The films were fabricated by solid phase crystallization of amorphous silicon deposited either by plasma enhanced chemical vapor deposition (PECVD) or by electron-beam evaporation (EBE). Three different rapid thermal processing (RTP) set-ups were compared: A conventional rapid thermal annealing oven, a dual wavelength laser annealing system and a movable two sided halogen lamp oven. The two latter processes utilize focused energy input for reducing the thermal load introduced into the glass substrates and thus lead to less deformation and impurity diffusion. Analysis of the structural and electrical properties of the poly-Si thin films was performed by Suns-V{sub OC} measurements and Raman spectroscopy. 1 cm{sup 2} cells were prepared for a selection of samples and characterized by I–V-measurements. The poly-Si material quality could be extremely enhanced, resulting in increase of the open circuit voltages from about 100 mV (EBE) and 170 mV (PECVD) in the untreated case up to 480 mV after processing.

  4. Broadband absorption enhancement in plasmonic thin-film solar cells with grating surface

    Science.gov (United States)

    Liu, Li; Huo, Yiping; Zhao, Kaijun; Zhao, Ting; Li, Yuan

    2015-10-01

    The plasmonic thin-film solar cells with grating surface is structured and simulated by Comsol Multiphysics software using finite element method. The absorption efficiency of solar cells has been systemically studied by considering structure characteristic parameters. The absorption of grating surface cell is much broader and stronger than that of smooth surface on a-Si at the wavelength from 400 to 700 nm. The value of total absorption efficiency (TAE) increases from 47% to 69.3%. The embedded Ag nanoparticle array contributes to the improvement of the absorption of a-Si at longer wavelength range. The localized surface plasmon resonance is induced by Ag nanoparticles, and so that the TAE is increased to 75.1% when the radius of nanoparticle is 60 nm at the bottom of a-Si with periodic width 200 nm. The grating surface always plays a role to suppress light scattering from the active region, so more light can be absorbed again by a-Si in the infrared-region. Therefore, the results have significance in providing a theoretical foundation for the applications of thin-film solar cell.

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

    Energy Technology Data Exchange (ETDEWEB)

    Compaan, Alvin D.; Plotnikov, Victor V.

    2014-09-09

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

  6. Engineering polymer-fullerene thin films and solar cells with external fields

    Science.gov (United States)

    Cabral, Joao

    2014-03-01

    Trace amounts of nanoparticles, including fullerenes, can impart stability to thin polymer films against dewetting by the combined effects of pinning the contact lines of dewetting holes and by effectively altering the polymer-substrate interaction. Polymer nanocomposite (meta)stable thin films can yield well-defined morphologies from uniform to spinodal-like, via spontaneous polymer-nanoparticle phase separation and crystallization. Confinement breaks the structural isotropy and generally causes (partial) segregation of components orthogonally to the film surface. Surface energy patterning can thus modulate composition and morphology, both in plane and normal to the surface. Further, UV-visible, and even background, light exposure, in both solutions and melts, is shown to tune the solution stucture and morphology of dewetting and phase separating polymer-fullerene thin films. Neutron reflectivity allows us to locate the various constituents within the film. We find a coupling of fullerene photo-sensitivity and both self-assembly processes which results in controlled pattern formation, and we illustrate the potential with a model polymer-fullerene circuit pattern. We then translate this approach into the directed assembly of energy harvesting bulk heterojunctions thin films. Indeed, a key challenge to the commercialization of organic solar cells remains the achievement of morphological stability, particularly under thermal stress conditions. The directed assembly a blend polymer:PC60BM solar cells via a simple light processing step results in a 10-100 fold increase in device thermal stability and, under certain conditions, enhanced device performance. The enhanced stability is linked to the light-induced oligomerisation of PC60BM that effectively hinders diffusion and crystallization in blends. This effect appears to be general and promises to be an effective and cost-effective strategy to optimize fullerene-based solar cell performance.

  7. Large CZTS Nanoparticles Synthesized by Hot-Injection for Thin Film Solar Cells

    DEFF Research Database (Denmark)

    Engberg, Sara Lena Josefin; Lam, Yeng Ming; Schou, Jørgen

    2015-01-01

    The kesterite material, Cu2ZnSn(SxSe1-x)4 (CZTS), shows great promise as the absorber layer for future thin film solar cells. Solution processing allows for comparatively fast and inexpensive fabrication, and holds the record efficiency in the kesterite family. However, for nanoparticle (NP) solution processing to be a feasible fabrication route, the amount of carbon in the film has to be limited. In our work, we try to limit the organic material in the film by synthesizing larger NPs. Larger pa...

  8. Unlinking absorption and haze in thin film silicon solar cells front electrodes

    OpenAIRE

    Boccard, Mathieu; Cuony, Peter; Battaglia, Corsin; Despeisse, Matthieu; Ballif, Christophe

    2010-01-01

    We study the respective influence of haze and free carrier absorption (FCA) of transparent front electrodes on the photogenerated current of micromorph thin film silicon solar cells. To decouple the haze and FCA we develop bi-layer front electrodes: a flat indium tin oxide layer assures conduction and allows us to tune FCA while the haze is adjusted by varying the thickness of a highly transparent rough ZnO layer. We show how a minimum amount of FCA leads only to a few percents absorption for...

  9. Self-organized broadband light trapping in thin film amorphous silicon solar cells

    International Nuclear Information System (INIS)

    Nanostructured glass substrates endowed with high aspect ratio one-dimensional corrugations are prepared by defocused ion beam erosion through a self-organized gold (Au) stencil mask. The shielding action of the stencil mask is amplified by co-deposition of gold atoms during ion bombardment. The resulting glass nanostructures enable broadband anti-reflection functionality and at the same time ensure a high efficiency for diffuse light scattering (Haze). It is demonstrated that the patterned glass substrates exhibit a better photon harvesting than the flat glass substrate in p–i–n type thin film a-Si:H solar cells. (paper)

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

    Energy Technology Data Exchange (ETDEWEB)

    Fonash, S.J. [Pennsylvania State Univ., University Park, PA (United States)

    1995-08-01

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

  11. Improved homogeneity of microcrystalline absorber layer in thin-film silicon tandem solar cells

    International Nuclear Information System (INIS)

    A study of the effects of microcrystalline silicon i-layer modification near p/i interface in tandem configuration silicon thin film solar cells is presented. The structural properties of the absorber layers were investigated by Raman spectroscopy at different stages of growth. The results indicate the possibility of improving both the nucleation process and the film homogeneity in the direction of growth, without specific re-optimization of the p-layer, transferred from a single-junction microcrystalline silicon cell. Structural modifications of the i-layer have been correlated with performance of tandem solar cells, leading to improvements in the bottom cell current Jsc (up to 11.4 mA/cm2) and initial tandem-cell conversion efficiency (up to 11.3%).

  12. Band alignment measurements at heterojunction interfaces in layered thin film solar cells & thermoelectrics

    Science.gov (United States)

    Fang, Fang

    2011-12-01

    Public awareness of the increasing energy crisis and the related serious environmental concerns has led to a significantly growing demand for alternative clean and renewable energy resources. Thin film are widely applied in multiple renewable energy devices owing to the reduced amount of raw materials and increase flexibility of choosing from low-cost candidates, which translates directly into reduced capital cost. This is a key driving force to make renewable technology competitive in the energy market. This thesis is focused on the measurement of energy level alignments at interfaces of thin film structures for renewable energy applications. There are two primary foci: II -VI semiconductor ZnSe/ZnTe thin film solar cells and Bi2Te3/Sb2Te3 thin film structures for thermoelectric applications. In both cases, the electronic structure and energy band alignment at interfaces usually controls the carrier transport behavior and determines the quality of the device. High-resolution photoemission spectroscopy (lab-based XPS & synchrotron-based UPS) was used to investigate the chemical and electronic properties of epitaxial Bi2Te3 and Sb2Te3 thin films, in order to validate the anticipated band alignment at interfaces in Bi 2Te3/Sb2Te3 superlattices as one favoring electron-transmission. A simple, thorough two-step treatment of a chemical etching in dilute hydrochloric acid solution and a subsequent annealing at ˜150°C under ultra-high vacuum environment is established to remove the surface oxides completely. It is an essential step to ensure the measurements on electronic states are acquired on stoichimetric, oxide-free clean surface of Bi 2Te3 and Sb2Te3 films. The direct measurement of valence band offsets (VBO) at a real Sb 2Te3/Bi2Te3 interface is designed based on the Kraut model; a special stacking film structure is prepared intentionally: sufficiently thin Sb2Te3 film on top of Bi2Te 3 that photoelectrons from both of them are collected simultaneously. From a combination of core levels and valence band ultraviolet photoemission spectra of the bulk materials as well as the heterojunction (Sb2Te 3/Bi2Te3), the VBO at p-type Sb2Te 3 and n-type Bi2Te3 is determined as 0.04 +/- 0.10 eV. Such a small energy offset is within the same magnitude of the thermal energy of kT, at room temperature. The motivation for the II-VI ZnTe-based thin film solar cell derives from the need to identify and overcome performance-limiting properties related to the processing of film deposition using close space sublimation (CSS). Chemical and electronic properties of the CSS grown ZnTe/ZnSe films were studied in x-ray diffraction, scanning electron microscopy and photoemission spectroscopy. Specifically, Se oxide was observed on the ZnSe surface, the removal of this oxide generated apparent offsets in the valence band and hence the alignment at the heterojunction energy diagram. Processing steps to mitigate oxidation yielded the best cells. Film structure was studied on the dependence of growth time; physical film damage is found during the initial stages when depositing ZnTe on a grown ZnSe film. Preliminary studies of films grown by evaporation and their characterizations are presented at last. In this thesis, a better understanding of the electronic structure at interfaces is built in two different thin film devices, and the resulting band energy diagram of the corresponding devices offered effective feedback in materials and device.The problem of energy equilibrium in the human body has received a great deal.

  13. Concepts for thin-film GaAs concentrator cells. [for solar photovoltaic space power systems

    Science.gov (United States)

    Spitzer, M. B.; Gale, R. P.; Mcclelland, R.; King, B.; Dingle, J.

    1989-01-01

    The development of advanced GaAs concentrator solar cells, and in particular, the use of CLEFT (cleavage of lateral epitaxial films for transfer) processes for formation of thin-film structures is reported. The use of CLEFT has made possible processing of the back, and cells with back surface grids are discussed. Data on patterned junction development are presented; such junctions are expected to be useful in back surface applications requiring point contacts, grating structures, and interdigitated back contacts. CLEFT concentrator solar cells with grids on the front and back surfaces are reported here; these cells are 4 microns thick and are bonded to glass covers for support. Air mass zero efficiency of 18.8 percent has been obtained for a CLEFT concentrator operating at 18.5 suns.

  14. Crystalline silicon for thin film solar cells. Final report; Kristallines Silizium fuer Duennschichtsolarzellen. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, H.

    2001-07-01

    Thin film solar cells based on silicon are of great interest for cost-effective conversion of solar energy into electric power. In order to reach this goal, intensive research is still necessary, pointing, e.g., to a further enhancement of the conversion efficiency, an improvement of stability and a reduction of the production time. Aim of the project work was the achievement of knowledge on microcrystalline silicon and its application in thin film solar cells by means of a broad research and development program. Material research focused on growth processes of the microcrystalline material, the incorporation and stability of hydrogen, the electronic transport and defects. In particular the transition from amorphous to microcrystalline material which is obtained for the present deposition methods by minor variations of the deposition parameters as well as the enhancement of the deposition rate were intensively studies. Another focus of research aimed toward the development and improvement of zinc oxide films which are of central importance for this type of solar cells for the application as transparent contacts. A comprehensive understanding was achieved. The films were incorporated in thin film solar cells and with conversion efficiencies >8% for single cells (at relatively high deposition rate) and 10% (stable) for tandem cells with amorphous silicon, top values were achieved by international standards. The project achievements serve as a base for a further development of this type of solar cell and for the transfer of this technology to industry. (orig.) [German] Duennschichtsolarzellen auf der Basis von Silizium sind von grossem Interesse fuer eine kostenguenstige Umwandlung von Sonnenenergie in elektrischen Strom. Um dieses Ziel zu erreichen, ist jedoch noch intensive Forschung, u.a. zur weiteren Steigerung des Wirkungsgrades, zur Verbesserung der Stabilitaet und zur Verkuerzung des Produktionsprozesses erforderlich. Ziel der Projektarbeiten war, durch ein breit angelegtes Forschungs- und Entwicklungsprogramm Kenntnisse ueber mikrokristallines Silizium und dessen Einsatzmoeglichkeit in Duennschichtsolarzellen zu gewinnen. Im Rahmen der Materialforschungzustanden Wachstumsprozesse von mirkrokristallinem Material, der Einbau und die Stabilitaet von Wasserstoff, der elektronische Transport und Defekte im Vordergrund. Insbesondere der Uebergang amorph-mikrokristallin, der bei den vorliegenden Depositionsmethoden durch geringfuegige Veraenderungen der Depositionsparameter erreicht werden kann, sowie eine Erhoehung der Depositionsrate wurden intensiv untersucht. Weiterhin wurden an der Entwicklung und Optimierung von Zinkoxidschichten gearbeitet, die fuer diesen Typ von Solarzellen als transparente Kontaktschichten von zentraler Bedeutung sind. Ein umfassendes Verstaendnis wurde erzielt. Die Schichten wurden in Duennschichtsolarzellen eingebaut und mit Wirkungsgraden >8% fuer Einzelzellen (bei relativ hohen Depositionsraten) und 10% (stabil) fuer Tandemsolarzellen mit amorphem Silizium wurden Spitzenwerte (im internationalen Vergleich) erreicht. Die Projektergebnisse dienen als Basis fuer die Weiterentwicklung dieses Solarzellentyps und fuer einen Transfer der Technologie in die Industrie. (orig.)

  15. Ultimate form freedom in thin film solar cells by postmanufacture laser-based processing

    Science.gov (United States)

    Gilot, Jan; Emelin, Baptiste; Galagan, Yulia; Mandamparambil, Rajesh; Andriessen, Ronn

    2015-01-01

    Thin film photovoltaics can be beneficial for specific applications like building integrated photovoltaics. To fully exploit the differentiator of form freedom, the interconnections in thin film modules can be tuned depending on the required module output. Traditionally, an alternation of coating and scribing steps is applied, determining the form from the start. Here, we present a set of techniques to define the module design from a master substrate with homogeneously coated electroactive layers. By applying subtractive and additive laser-based processes, the size and form of the module are only fixed after the manufacturing of the whole solar cell stack. By laser-induced forward transfer, an isolating dielectric material and a conductive top electrode are deposited in laser ablated scribes to enable the interconnection between two adjacent cells. After optimization of the laser settings for ablation and forward transfer, the optimal annealing time and temperature for the curing of the silver top electrode were determined. The proof of principle was demonstrated by constructing a 4-cell organic solar module of 1.0% efficiency on an area of over 3 cm2 showing the anticipated short-circuit current and open-circuit voltage.

  16. ZnO transparent conductive oxide for thin film silicon solar cells

    Science.gov (United States)

    Söderström, T.; Dominé, D.; Feltrin, A.; Despeisse, M.; Meillaud, F.; Bugnon, G.; Boccard, M.; Cuony, P.; Haug, F.-J.; Faÿ, S.; Nicolay, S.; Ballif, C.

    2010-03-01

    There is general agreement that the future production of electric energy has to be renewable and sustainable in the long term. Photovoltaic (PV) is booming with more than 7GW produced in 2008 and will therefore play an important role in the future electricity supply mix. Currently, crystalline silicon (c-Si) dominates the market with a share of about 90%. Reducing the cost per watt peak and energy pay back time of PV was the major concern of the last decade and remains the main challenge today. For that, thin film silicon solar cells has a strong potential because it allies the strength of c-Si (i.e. durability, abundancy, non toxicity) together with reduced material usage, lower temperature processes and monolithic interconnection. One of the technological key points is the transparent conductive oxide (TCO) used for front contact, barrier layer or intermediate reflector. In this paper, we report on the versatility of ZnO grown by low pressure chemical vapor deposition (ZnO LP-CVD) and its application in thin film silicon solar cells. In particular, we focus on the transparency, the morphology of the textured surface and its effects on the light in-coupling for micromorph tandem cells in both the substrate (n-i-p) and superstrate (p-i-n) configurations. The stabilized efficiencies achieved in Neuchâtel are 11.2% and 9.8% for p-i-n (without ARC) and n-i-p (plastic substrate), respectively.

  17. Morphology dependent dye-sensitized solar cell properties of nanocrystalline zinc oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, S.K., E-mail: sanjeevlrs732000@yahoo.co.in [Department of Information and Communication, Cheju Halla College, Jeju City 690 708 (Korea, Republic of); Inamdar, A.I.; Im, Hyunsik [Department of Semiconductor Science, Dongguk University, Seoul 100 715 (Korea, Republic of); Kim, B.G. [Department of Information and Communication, Cheju Halla College, Jeju City 690 708 (Korea, Republic of); Patil, P.S. [Thin Film Materials Laboratory, Department of Physics, Shivaji University, Kolhapur 416 004 (India)

    2011-02-03

    Research highlights: > Nano-crystalline zinc oxide thin films were electrosynthesized from an aqueous zinc acetate [Zn(CH{sub 3}COO){sub 2}.2H{sub 2}O] solution onto FTO coated conducting glass substrates using two different electrochemical routes, namely (i) without an organic surfactant and (ii) with an organic surfactant, viz. PVA (poly-vinyl alcohol) or SDS (sodium dodecyl sulfate). > The reproducibility of the catalytic activity of the SDS and PVA surfactants in the modification of the morphologies was observed. > Vertically aligned nest-like and compact structures were observed from the SDS and PVA mediated films, respectively, while the grain size in the ZnO thin films without an organic surfactant was observed to be {approx}150 nm. > The dye sensitized ZnO electrodes displayed excellent properties in the conversion process from light to electricity. The efficiencies of the surfactant mediated nanocrystalline ZnO thin films, viz. ZnO:SDS and ZnO:PVA, sensitized with ruthenium-II (N3) dye were observed to be 0.49% and 0.27%, respectively. - Abstract: Nano-crystalline zinc oxide thin films were electrosynthesized with an aqueous zinc acetate [Zn(CH{sub 3}COO){sub 2}.2H{sub 2}O] solution on to FTO coated glass substrates. Two different electrochemical baths were used, namely (i) without an organic surfactant and (ii) with an organic surfactant, viz. PVA (poly-vinyl alcohol) and SDS (sodium dodecyl sulfate). The organic surfactants played an important role in modifying the surface morphology, which influenced the size of the crystallites and dye-sensitized solar cell (DSSC) properties. The vertically aligned thin and compact hexagonal crystallites were observed with SDS mediated films, while the grain size in the films without an organic surfactant was observed to be {approx}150 nm. The conversion efficiencies of the ZnO:SDS:Dye and ZnO:PVA:Dye thin films were observed to be 0.49% and 0.27%, respectively.

  18. Light trapping in thin film solar cells using photonic engineering device concepts

    Science.gov (United States)

    Mutitu, James Gichuhi

    In this era of uncertainty concerning future energy solutions, strong reservations have arisen over the continued use and pursuit of fossil fuels and other conventional sources of energy. Moreover, there is currently a strong and global push for the implementation of stringent measures, in order to reduce the amount of green house gases emitted by every nation. As a consequence, there has emerged a sudden and frantic rush for new renewable energy solutions. In this world of renewable energy technologies is where we find photovoltaic (PV) technology today. However, as is, there are still many issues that need to be addressed before solar energy technologies become economically viable and available to all people, in every part of the world. This renewed interest in the development of solar electricity, has led to the advancement of new avenues that address the issues of cost and efficiency associated with PV. To this end, one of the prominent approaches being explored is thin film solar cell (TFSC) technology, which offers prospects of lower material costs and enables larger units of manufacture than conventional wafer based technology. However, TFSC technologies suffer from one major problem; they have lower efficiencies than conventional wafer based solar cell technologies. This lesser efficiency is based on a number of reasons, one of which is that with less material, there is less volume for the absorption of incident photons. This shortcoming leads to the need for optical light trapping; which is concerned with admitting the maximum amount of light into the solar cell and keeping the light within the structure for as long as possible. In this thesis, I present the fundamental scientific ideas, practice and methodology behind the application of photonic engineering device concepts to increase the light trapping capacity of thin film solar cells. In the introductory chapters, I develop the basic ideas behind light trapping in a sequential manner, where the effects of the inclusion of various structures on the front and back surfaces of solar cells are examined. This framework is then adapted as a basis for the development of more advanced topics, such as the inclusion of micro and nano scale surface textures, diffraction gratings and photonic bandgap structures. Analyses of the effects of these light trapping structures is undertaken using performance metrics, such as the short circuit current characteristics and a band-edge enhancement factor, which all serve to quantitatively demonstrate the effects of the optical enhancements. I begin this thesis with an investigation of one dimensional photonic crystals, which are used as selective light filters between vertically stacked tandem multi-junction solar cells. These ideas are then further developed for single junction stand alone thin film solar cells, where the optical enhancement is shown to be very significant. A further investigation on the application of engineered photonic crystal materials as angular selective light filters is then presented; these filters are shown to overcome the physical limitations of light trapping that are imposed by the optical properties of materials; specifically limitations associated with total internal reflection. In the next part of this thesis, I present a fundamental redesign approach to multiple period distributed Bragg reflectors (DBR's) and their applications to solar cell light trapping. As it turns out, multiple period DBR's, which are required for high back surface reflectance - which is especially necessary in thin film solar cells - present formidable challenges in terms of cost and complexity when considered for high volume manufacturing. To this end, I show that when a single period DBR is combined with a phase matching and metallic layer, the combined structure can achieve high back surface reflectance that is comparable to that of a DBR structure with many more layers. This new structure reduces the back reflector complexity and is hence, amenable to large scale fabrication processes. In the latter sections of this thes

  19. Solid-phase crystallization of amorphous silicon on ZnO:Al for thin-film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Becker, C.; Conrad, E.; Dogan, P.; Fenske, F.; Gorka, B.; Haenel, T.; Lee, K.Y.; Rau, B.; Ruske, F.; Weber, T.; Gall, S.; Rech, B. [Helmholtz-Zentrum Berlin fuer Materialien und Energie (formerly Hahn-Meitner-Institut Berlin), Kekulestr. 5, D-12489 Berlin (Germany); Berginski, M.; Huepkes, J. [Institute of Photovoltaics, Forschungszentrum Juelich GmbH, D-52425 Juelich (Germany)

    2009-06-15

    The suitability of ZnO:Al thin films for polycrystalline silicon (poly-Si) thin-film solar cell fabrication was investigated. The electrical and optical properties of 700 -nm-thick ZnO:Al films on glass were analyzed after typical annealing steps occurring during poly-Si film preparation. If the ZnO:Al layer is covered by a 30 nm thin silicon film, the initial sheet resistance of ZnO:Al drops from 4.2 to 2.2 {omega} after 22 h annealing at 600 C and only slightly increases for a 200 s heat treatment at 900 C. A thin-film solar cell concept consisting of poly-Si films on ZnO:Al coated glass is introduced. First solar cell results will be presented using absorber layers either prepared by solid-phase crystallization (SPC) or by direct deposition at 600 C. (author)

  20. Microcrystalline silicon carbide alloys prepared with HWCVD as highly transparent and conductive window layers for thin film solar cells

    International Nuclear Information System (INIS)

    Crystalline silicon carbide alloys have a very high potential as transparent conductive window layers in thin-film solar cells provided they can be prepared in thin-film form and at compatible deposition temperatures. The low-temperature deposition of such material in microcrystalline form (?c-Si:C:H) was realized by use of monomethylsilane precursor gas diluted in hydrogen with the Hot-Wire Chemical Vapor Deposition process. A wide range of deposition parameters has been investigated and the structural, electronic and optical properties of the ?c-SiC:H thin films have been studied. The material, which is strongly n-type from unintentional doping, has been used as window layer in n-side illuminated microcrystalline silicon solar cells. High short-circuit current densities are obtained due to the high transparency of the material resulting in a maximum solar cell conversion efficiency of 9.2%.

  1. Light Trapping in Thin Film Silicon Solar Cells on Plastic Substrates

    Science.gov (United States)

    de Jong, M. M.

    2013-01-01

    In the search for sustainable energy sources, solar energy can fulfil a large part of the growing demand. The biggest threshold for large-scale solar energy harvesting is the solar panel price. For drastic cost reductions, roll-to-roll fabrication of thin film silicon solar cells using plastic substrates can be a solution. In this thesis, we investigate the possibilities of depositing thin film solar cells directly onto cheap plastic substrates. Micro-textured glass and sheets, which have a wide range of applications, such as in green house, lighting etc, are applied in these solar cells for light trapping. Thin silicon films can be produced by decomposing silane gas, using a plasma process. In these types of processes, the temperature of the growing surface has a large influence on the quality of the grown films. Because plastic substrates limit the maximum tolerable substrate temperature, new methods have to be developed to produce device-grade silicon layers. At low temperature, polysilanes can form in the plasma, eventually forming dust particles, which can deteriorate device performance. By studying the spatially resolved optical emission from the plasma between the electrodes, we can identify whether we have a dusty plasma. Furthermore, we found an explanation for the temperature dependence of dust formation; Monitoring the formation of polysilanes as a function of temperature using a mass-spectrometer, we observed that the polymerization rate is indeed influenced by the substrate temperature. For solar cell substrate material, our choice was polycarbonate (PC), because of its low cost, its excellent transparency and its relatively high glass transition temperature of 130-140°C. At 130°C we searched for deposition recipes for device quality silicon, using a very high frequency plasma enhanced chemical deposition process. By diluting the feedstock silane with hydrogen gas, the silicon quality can be improved for amorphous silicon (a-Si), until we reach the nanocrystalline silicon (nc-Si) regime. In the nc-Si regime, the crystalline fraction can be further controlled by changing the power input into the plasma. With these layers, a-Si thin film solar cells were fabricated, on glass and PC substrates. The adverse effect of the low temperature growth on the photoactive material is further mitigated by using thinner silicon layers, which can deliver a good current only with an adequate light trapping technique. We have simulated and experimentally tested three light trapping techniques, using embossed structures in PC substrates and random structures on glass: regular pyramid structures larger than the wavelength of light (micropyramids), regular pyramid structures comparable to the wavelength of light (nanopyramids) and random nano-textures (Asahi U-type). The use of nanostructured polycarbonate substrates results in initial conversion efficiencies of 7.4%, compared to 7.6% for cells deposited under identical conditions on Asahi U-type glass. The potential of manufacturing thin film solar cells at processing temperatures lower than 130oC is further illustrated by obtained results on texture-etched aluminium doped zinc-oxide (ZnO:Al) on glass: we achieved 6.9% for nc-Si cells using a very thin absorber layer of only 750 nm, and by combining a-Si and nc-Si cells in tandem solar cells we reached an initial conversion efficiency of 9.5%.

  2. Plasmonic enhancement of thin-film solar cells using gold-black coatings

    Energy Technology Data Exchange (ETDEWEB)

    Fredricksen, Christopher J.; Panjwani, D. R.; Arnold, J. P.; Figueiredo, P. N.; Rezaie, F. K.; Colwell, J. E.; Baillie, K.; Peppernick, Samuel J.; Joly, Alan G.; Beck, Kenneth M.; Hess, Wayne P.; Peale, Robert E.

    2011-08-11

    Coatings of conducting gold-black nano-structures on commercial thin-film amorphous-silicon solar cells enhance the short-circuit current by 20% over a broad spectrum from 400 to 800 nm wavelength. The efficiency, i.e. the ratio of the maximum electrical output power to the incident solar power, is found to increase 7% for initial un-optimized coatings. Metal blacks are produced cheaply and quickly in a low-vacuum process requiring no lithographic patterning. The inherently broad particle-size distribution is responsible for the broad spectrum enhancement in comparison to what has been reported for mono-disperse lithographically deposited or self-assembled metal nano-particles. Photoemission electron microscopy reveals the spatial-spectral distribution of hot-spots for plasmon resonances, where scattering of normally-incident solar flux into the plane increases the effective optical path in the thin film to enhance light harvesting. Efficiency enhancement is correlated with percent coverage and particle size distribution, which are determined from histogram and wavelet analysis of scanning electron microscopy images. Electrodynamic simulations reveal how the gold-black particles scatter the radiation and locally enhance the field strength.

  3. Deep level transient spectroscopy measurements on CuInS2-thin film solar cells

    International Nuclear Information System (INIS)

    During the last decade CuInS2 was investigated for its use as absorber in thin film solar cells. Now these cells are ready for volume production. The advantages against already used materials are e. g. high absorbing capacity and cost-efficient and sustainable production. Because of the great discrepancy between predicted degree of efficiency and the already reached degree more investigations are necessary. To get a better understanding of the electron transport and recombination in order to arise efficiency we characterize the solar cells by deep level transient spectroscopy (DLTS). This method gives information about crystal defects depending on their electric position. Transient capacity measurements in the range of 25 K and 350 K allow us to determine activation energy and concentration of electron traps

  4. Copper and Transparent-Conductor Reflectarray Elements on Thin-Film Solar Cell Panels

    CERN Document Server

    Dreyer, Philippe; Nicolay, Sylvain; Ballif, Christophe; Perruisseau-Carrier, Julien

    2013-01-01

    This work addresses the integration of reflectarray antennas (RA) on thin film Solar Cell (SC) panels, as a mean to save real estate, weight, or cost in platforms such as satellites or transportable autonomous antenna systems. Our goal is to design a good RA unit cell in terms of phase response and bandwidth, while simultaneously achieving high optical transparency and low microwave loss, to preserve good SC and RA energy efficiencies, respectively. Since there is a trade-off between the optical transparency and microwave surface conductivity of a conductor, here both standard copper and transparent conductors are considered. The results obtained at the unit cell level demonstrates the feasibility of integrating RA on a thin-film SC, preserving for the first time good performance in terms of both SC and RA efficiency. For instance, measurement at X-band demonstrate families of cells providing a phase range larger than 270{\\deg} with average microwave loss of -2.45dB (resp. -0.25dB) and average optical transpa...

  5. Time Domain Characterization of Light Trapping States in Thin Film Solar Cells

    Directory of Open Access Journals (Sweden)

    Pfeiffer W.

    2013-03-01

    Full Text Available Spectral interferometry of the backscattered radiation reveals coherence lifetimes of about 150 fs for nanolocalized electromagnetic modes in textured layered nanostructures as they are commonly used in thin film photovoltaics to achieve high cell efficiencies.

  6. A fast deposition-crystallization procedure for highly efficient lead iodide perovskite thin-film solar cells.

    Science.gov (United States)

    Xiao, Manda; Huang, Fuzhi; Huang, Wenchao; Dkhissi, Yasmina; Zhu, Ye; Etheridge, Joanne; Gray-Weale, Angus; Bach, Udo; Cheng, Yi-Bing; Spiccia, Leone

    2014-09-01

    Thin-film photovoltaics based on alkylammonium lead iodide perovskite light absorbers have recently emerged as a promising low-cost solar energy harvesting technology. To date, the perovskite layer in these efficient solar cells has generally been fabricated by either vapor deposition or a two-step sequential deposition process. We report that flat, uniform thin films of this material can be deposited by a one-step, solvent-induced, fast crystallization method involving spin-coating of a DMF solution of CH3NH3PbI3 followed immediately by exposure to chlorobenzene to induce crystallization. Analysis of the devices and films revealed that the perovskite films consist of large crystalline grains with sizes up to microns. Planar heterojunction solar cells constructed with these solution-processed thin films yielded an average power conversion efficiency of 13.9±0.7% and a steady state efficiency of 13% under standard AM 1.5 conditions. PMID:25047967

  7. Thin film CdTe solar cells by close spaced sublimation: Recent results from pilot line

    Energy Technology Data Exchange (ETDEWEB)

    Siepchen, B., E-mail: bastian.siepchen@ctf-solar.com [CTF Solar GmbH, Industriestraße 2, 65779 Kelkheim (Germany); Drost, C.; Späth, B.; Krishnakumar, V.; Richter, H.; Harr, M. [CTF Solar GmbH, Industriestraße 2, 65779 Kelkheim (Germany); Bossert, S.; Grimm, M. [Roth and Rau AG, An der Baumschule 6-8, 09337 Hohenstein-Ernstthal (Germany); Häfner, K.; Modes, T.; Zywitzki, O.; Morgner, H. [Fraunhofer Institute for Electron Beam and Plasma Technology FEP, Winterbergstrasse 28, 01277 Dresden (Germany)

    2013-05-01

    CdTe is an attractive material to produce high efficient and low cost thin film solar cells. The semiconducting layers of this kind of solar cell can be deposited by the Close Spaced Sublimation (CSS) process. The advantages of this technique are high deposition rates and an excellent utilization of the raw material, leading to low production costs and competitive module prices. CTF Solar GmbH is offering equipment and process knowhow for the production of CdTe solar modules. For further improvement of the technology, research is done at a pilot line, which covers all relevant process steps for manufacture of CdTe solar cells. Herein, we present the latest results from the process development and our research activities on single functional layers as well as for complete solar cell devices. Efficiencies above 13% have already been obtained with Cu-free back contacts. An additional focus is set on different transparent conducting oxide materials for the front contact and a Sb{sub 2}Te{sub 3} based back contact. - Highlights: ? Laboratory established on industrial level for CdTe solar cell research ? 13.0% cell efficiency with our standard front contact and Cu-free back contact ? Research on ZnO-based transparent conducting oxide and Sb{sub 2}Te{sub 3} back contacts ? High resolution scanning electron microscopy analysis of ion polished cross section.

  8. Thin film CdTe solar cells by close spaced sublimation: Recent results from pilot line

    International Nuclear Information System (INIS)

    CdTe is an attractive material to produce high efficient and low cost thin film solar cells. The semiconducting layers of this kind of solar cell can be deposited by the Close Spaced Sublimation (CSS) process. The advantages of this technique are high deposition rates and an excellent utilization of the raw material, leading to low production costs and competitive module prices. CTF Solar GmbH is offering equipment and process knowhow for the production of CdTe solar modules. For further improvement of the technology, research is done at a pilot line, which covers all relevant process steps for manufacture of CdTe solar cells. Herein, we present the latest results from the process development and our research activities on single functional layers as well as for complete solar cell devices. Efficiencies above 13% have already been obtained with Cu-free back contacts. An additional focus is set on different transparent conducting oxide materials for the front contact and a Sb2Te3 based back contact. - Highlights: ? Laboratory established on industrial level for CdTe solar cell research ? 13.0% cell efficiency with our standard front contact and Cu-free back contact ? Research on ZnO-based transparent conducting oxide and Sb2Te3 back contacts ? High resolution scanning electron microscopy analysis of ion polished cross section

  9. A non-resonant dielectric metamaterial for the enhancement of thin-film solar cells

    International Nuclear Information System (INIS)

    Recently, we have suggested a dielectric metamaterial composed of an array of submicron dielectric spheres located on top of an amorphous thin-film solar cell. We have theoretically shown that this metamaterial can decrease the reflection and simultaneously suppress the transmission through the photovoltaic layer because it transforms the incident plane wave into a set of focused light beams. This theoretical concept has been strongly developed and experimentally confirmed in the present paper. Here we consider the metamaterial for oblique angle illumination, redesign the solar cell and present a detailed experimental study of the whole structure. In contrast to our previous theoretical study we show that our omnidirectional light-trapping structure may operate better than the optimized flat coating obtained by plasma-enhanced chemical vapor deposition. (paper)

  10. A non-resonant dielectric metamaterial for enhancement of thin-film solar cells

    CERN Document Server

    Omelyanovich, Mikhail; Simovski, Constantin

    2014-01-01

    Recently, we have suggested dielectric metamaterial composed as an array of submicron dielectric spheres located on top of an amorphous thin-film solar cell. We have theoretically shown that this metamaterial can decrease the reflection and simultaneously can suppress the transmission through the photovoltaic layer because it transforms the incident plane wave into a set of focused light beams. This theoretical concept has been strongly developed and experimentally confirmed in the present paper. Here we consider the metamaterial for oblique angle illumination, redesign the solar cell and present a detailed experimental study of the whole structure. In contrast to our precedent theoretical study we show that our omnidirectional light-trapping structure may operate better than the optimized flat coating obtained by plasma-enhanced chemical vapor deposition.

  11. Spectral analysis of the angular distribution function of back reflectors for thin film silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Escarre, J.; Villar, F.; Asensi, J.M.; Bertomeu, J.; Andreu, J. [CeRMAE - Departament de Fisica Aplicada i Optica, Universitat de Barcelona, Av. Diagonal 647, 08028 Barcelona (Spain)

    2006-06-15

    Nowadays, one of the most important challenges to enhance the efficiency of thin film silicon solar cells is to increase the short circuit intensity by means of optical confinement methods, such as textured back-reflector structures. In this work, two possible textured structures to be used as back reflectors for n-i-p solar cells have been optically analyzed and compared to a smooth one by using a system which is able to measure the angular distribution function (ADF) of the scattered light in a wide spectral range (350-1000nm). The accurate analysis of the ADF data corresponding to the reflector structures and to the {mu}c-Si:H films deposited onto them allows the optical losses due to the reflector absorption and its effectiveness in increasing light absorption in the {mu}c-Si:H layer, mainly at long wavelengths, to be quantified. (author)

  12. Hydrophobic perfluoropolymer thin-film encapsulation for enhanced stability of inverted polymer solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae-Hyun; Park, Sung Kyu [Chung-Ang University, Seoul (Korea, Republic of); Lee, Jung-Wook; Yoo, Byung-Wook [Korea Electronics Technology Institute, Seongnam (Korea, Republic of); Lee, Jin-Kyun [Inha University, Incheon (Korea, Republic of); Kim, Yong-Hoon [Sungkyunkwan University, Suwon (Korea, Republic of)

    2014-11-15

    We report hydrophobic perfluoropolymer thin-film encapsulation for enhancing the air ambient stability of inverted polymer solar cells (PSCs). Using a perfluoropolymer, poly(perfluorodecylmethacrylate) (PFDMA), as an encapsulation material, an orthogonal process that enables a solution-processing of encapsulation polymers to be coated directly on the inverted PSCs without damaging the underlying organic components is possible. Particularly, with PFDMA encapsulation, the air ambient stability was significantly enhanced, showing only an efficiency reduction of 23.3% after 456 hours of air exposure. The enhanced device stability can be attributed to the hydrophobic property of the PFDMA surface, which suppresses the transmission of air ambient gas molecules into the solar cells. Thus, the PFDMA coating can be beneficial in achieving high-stability organic electronics by using an easy-to-use route.

  13. Laser crystallization induced multicrystalline silicon thin film solar cells on glass : European High-EF Project

    International Nuclear Information System (INIS)

    The European project HIGH-EF is aimed at developing a unique process for silicon thin films based solar cells on glass substrate. To provide high solar cells efficiency (? 12 percent), a combination of laser crystallization of a seed layer and an additional solid phase epitaxy of a thicker layer is realized. In a first step, the crystallization of the seed layer is obtained by scanning a focused in-line laser beam obtained by a specific optical lens system. In a second step, epitaxial growth of a large grains active silicon layer is achieved by solid phase epitaxy. Process optimization is supported by numerical simulations of both melting and crystallization process of the seed layer as well as epitaxial solid phase crystallization

  14. Laser crystallization induced multicrystalline silicon thin film solar cells on glass : european HIGH-EF project

    International Nuclear Information System (INIS)

    The european project HIGH-EF is aimed at developing a unique process for silicon thin films based solar cells on glass substrate. To provide high solar cells efficiency (more than 12 percent) a combination of laser crystallization of a seed layer and an additional solid phase epitaxy of thicker layer is realized. In a first step, the crystallization of the seed layer is obtained by scanning a focused in-line laser beam obtained by a specific optical lens system. In a second step, epitaxial growth of a large grains active silicon layer is achieved by solid phase epitaxy. Process optimization is supported by numerical simulations of both melting and crystallization process of the seed layer as well as epitaxial solid phase crystallization

  15. Thin film solar cells on glass by transfer of monocrystalline Si films

    Directory of Open Access Journals (Sweden)

    J. H. Werner

    1999-01-01

    Full Text Available Thin film solar cells based on monocrystalline Si films are transferred to a glass superstrate. Chemical vapor deposition serves to epitaxially deposit Si on quasi-monocrystalline Si films obtained from thermal crystallization of a double layer porous Si film on a Si wafer. A separation layer that forms during this crystallization process allows one to separate the epitaxial layer on top of the quasi-monocrystalline film from the starting Si wafer. We presently achieve an independently confirmed solar cell conversion efficiency of 9:26%. Ray tracing studies in combination with electrical device simulation indicate an efficiency potential of around 17% using simple device processing and moderate assumptions on minority carrier lifetime and surface recombination.

  16. Epitaxially grown polycrystalline silicon thin-film solar cells on solid-phase crystallised seed layers

    International Nuclear Information System (INIS)

    Highlights: • Crystallisation kinetic is used to analyse seed layer surface cleanliness. • Simplified RCA cleaning for the seed layer can shorten the epitaxy annealing duration. • RTA for the seed layer can improve the quality for both seed layer and epi-layer. • Epitaxial poly-Si solar cell performance is improved by RTA treated seed layer. - Abstract: This paper presents the fabrication of poly-Si thin film solar cells on glass substrates using seed layer approach. The solid-phase crystallised P-doped seed layer is not only used as the crystalline template for the epitaxial growth but also as the emitter for the solar cell structure. This paper investigates two important factors, surface cleaning and intragrain defects elimination for the seed layer, which can greatly influence the epitaxial grown solar cell performance. Shorter incubation and crystallisation time is observed using a simplified RCA cleaning than the other two wet chemical cleaning methods, indicating a cleaner seed layer surface is achieved. Cross sectional transmission microscope images confirm a crystallographic transferal of information from the simplified RCA cleaned seed layer into the epi-layer. RTA for the SPC seed layer can effectively eliminate the intragrain defects in the seed layer and improve structural quality of both of the seed layer and the epi-layer. Consequently, epitaxial grown poly-Si solar cell on the RTA treated seed layer shows better solar cell efficiency, Voc and Jsc than the one on the seed layer without RTA treatment

  17. Effect of Ag doping on opto-electrical properties of CdS thin films for solar cell applications

    International Nuclear Information System (INIS)

    Highlights: • Polycrystalline CdS thin films are fabricated by means of Close Spaced Sublimation technique. • Ag is doped by simple ion-exchange technique in order to reduce resistivity of CdS thin films. • Remarkable reduction in resistivity without introducing many transparency losses. - Abstract: Cadmium sulfide (CdS) polycrystalline thin films of different thicknesses (ranging from 370 nm to 750 nm) were fabricated on corning glass substrates using Close Spaced Sublimation (CSS) technique. Optical and electrical investigation revealed that CdS thin films show an appreciable transparency (50–70% transmission) in visible range and a highly resistive behavior (106 ? cm). Samples were doped by silver (Ag) at different concentrations, using ion exchange technique, in order to reduce the resistivity of CdS thin films and to improve their efficiency as a window layer for solar cell application. The doping of Ag in pure CdS thin films resulted into an increase of surface roughness and a decrease both in electrical resistivity and in transparency. By optimizing annealing parameters, we were able to properly control the optical properties of the present system. In fact, the Ag doping of pure CdS films has led to a decrease of the sample resistivity by three orders of magnitude (103 ? cm) against a 20% cut in optical transmission

  18. Studies of compositional dependent CZTS thin film solar cells by pulsed laser deposition technique: An attempt to improve the efficiency

    International Nuclear Information System (INIS)

    Highlights: ? Synthesis of CZTS thin films by PLD. ? Effect of stoichiometry, its deviation on the physical properties. ? Improvement in conversion efficiency using CZTS absorber layer. - Abstract: The performance of CZTS thin films deposited by using pulsed laser deposition technique is investigated as a function of target composition. The chemical composition ratio a = Cu/(Zn + Sn) of the target material has been varied from 0.8 to 1.2 in step of 0.1 by keeping Zn/Sn constant. The effect of the chemical composition in the precursor thin films on the structural, morphological, chemical and optical properties of the CZTS thin films has been investigated. X-ray diffraction and X-ray photoelectron spectroscopy studies showed that the annealed CZTS thin films are of a single kesterite crystal structure without any other secondary phases. The direct band gap energy of the CZTS thin films is found to decrease from 1.72–1.53 eV with increase of ‘a’. The estimated band-gap energy from the quantum efficiency measurements is about 1.54 eV. The solar cell fabricated with Glass/Mo/CZTS/CdS/ZnO:Al/Al structure grown using [a = Cu/(Zn + Sn) = 1.1] showed the best conversion efficiency of 4.13% with Voc = 700 mV, Jsc = 10.01 mA/cm2 and FF = 0.59.

  19. A two-layer structured PbI2 thin film for efficient planar perovskite solar cells.

    Science.gov (United States)

    Ying, Chao; Shi, Chengwu; Wu, Ni; Zhang, Jincheng; Wang, Mao

    2015-07-28

    In this paper, a two-layer structured PbI2 thin film was constructed by the spin-coating procedure using a 0.80 M PbI2 solution in DMF and subsequent close-spaced vacuum thermal evaporation using PbI2 powder as a source. The bottom PbI2 thin film was compact with a sheet-like appearance, parallel to the FTO substrate, and can be easily converted to a compact perovskite thin film to suppress the charge recombination of the electrons of the TiO2 conduction band and the holes of the spiro-OMeTAD valence band. The top PbI2 thin film was porous with nano-sheet arrays, perpendicular to the FTO substrate, and can be easily converted to a porous perovskite thin film to improve the hole migration from the perovskite to spiro-OMeTAD and the charge separation at the perovskite/spiro-OMeTAD interface. The planar perovskite solar cells based on the two-layer structured PbI2 thin film exhibited a photoelectric conversion efficiency of 11.64%, along with an open-circuit voltage of 0.90 V, a short-circuit photocurrent density of 19.29 mA cm(-2) and a fill factor of 0.67. PMID:26118756

  20. Effect of Ag doping on opto-electrical properties of CdS thin films for solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Nazir, Adnan, E-mail: adnan.nazir@iit.it [Istituto Italiano di Tecnologia, Via Morego 30, I-16163 Genova (Italy); School of Chemical and Materials Engineering, National University of Sciences and Technology, Islamabad (Pakistan); Toma, Andrea [Istituto Italiano di Tecnologia, Via Morego 30, I-16163 Genova (Italy); Shah, Nazar Abbas [Department of Physics, COMSATS Institute of Information Technology, Islamabad (Pakistan); Panaro, Simone [Istituto Italiano di Tecnologia, Via Morego 30, I-16163 Genova (Italy); Butt, Sajid [Department of Materials Science and Engineering, Institute of Space Technology (IST), Islamabad 44000 (Pakistan); School of Chemical and Materials Engineering, National University of Sciences and Technology, Islamabad (Pakistan); Sagar, Rizwan ur Rehman [Department of Physics, COMSATS Institute of Information Technology, Islamabad (Pakistan); Raja, Waseem [Istituto Italiano di Tecnologia, Via Morego 30, I-16163 Genova (Italy); Rasool, Kamran [Micro and Nano Devices Group, Department of Metallurgy and Materials Engineering Pakistan, Institute of Engineering and Applied Sciences (PIEAS), P.O. Nilore, Islamabad 45650 (Pakistan); Maqsood, Asghari [Department of Physics, Air University, Islamabad (Pakistan)

    2014-10-01

    Highlights: • Polycrystalline CdS thin films are fabricated by means of Close Spaced Sublimation technique. • Ag is doped by simple ion-exchange technique in order to reduce resistivity of CdS thin films. • Remarkable reduction in resistivity without introducing many transparency losses. - Abstract: Cadmium sulfide (CdS) polycrystalline thin films of different thicknesses (ranging from 370 nm to 750 nm) were fabricated on corning glass substrates using Close Spaced Sublimation (CSS) technique. Optical and electrical investigation revealed that CdS thin films show an appreciable transparency (50–70% transmission) in visible range and a highly resistive behavior (10{sup 6} ? cm). Samples were doped by silver (Ag) at different concentrations, using ion exchange technique, in order to reduce the resistivity of CdS thin films and to improve their efficiency as a window layer for solar cell application. The doping of Ag in pure CdS thin films resulted into an increase of surface roughness and a decrease both in electrical resistivity and in transparency. By optimizing annealing parameters, we were able to properly control the optical properties of the present system. In fact, the Ag doping of pure CdS films has led to a decrease of the sample resistivity by three orders of magnitude (10{sup 3} ? cm) against a 20% cut in optical transmission.

  1. A two-layer structured PbI2 thin film for efficient planar perovskite solar cells

    Science.gov (United States)

    Ying, Chao; Shi, Chengwu; Wu, Ni; Zhang, Jincheng; Wang, Mao

    2015-07-01

    In this paper, a two-layer structured PbI2 thin film was constructed by the spin-coating procedure using a 0.80 M PbI2 solution in DMF and subsequent close-spaced vacuum thermal evaporation using PbI2 powder as a source. The bottom PbI2 thin film was compact with a sheet-like appearance, parallel to the FTO substrate, and can be easily converted to a compact perovskite thin film to suppress the charge recombination of the electrons of the TiO2 conduction band and the holes of the spiro-OMeTAD valence band. The top PbI2 thin film was porous with nano-sheet arrays, perpendicular to the FTO substrate, and can be easily converted to a porous perovskite thin film to improve the hole migration from the perovskite to spiro-OMeTAD and the charge separation at the perovskite/spiro-OMeTAD interface. The planar perovskite solar cells based on the two-layer structured PbI2 thin film exhibited a photoelectric conversion efficiency of 11.64%, along with an open-circuit voltage of 0.90 V, a short-circuit photocurrent density of 19.29 mA cm-2 and a fill factor of 0.67.

  2. Cu(In,Ga)Se2 thin films processed by co-evaporation and their application into solar cells

    Scientific Electronic Library Online (English)

    J., Sastré-Hernández; M.E., Calixto; M., Tufiño-Velázquez; G., Contreras-Puente; A., Morales-Acevedo; G., Casados-Cruz; M.A., Hernández-Pérez; M.L., Albor-Aguilera; R., Mendoza-Pérez.

    2011-10-11

    Full Text Available Polycrystalline Cu(In,Ga)Se2 (CIGS) solar cells are attractive because low cost techniques can be used to obtain high efficiency thin film photovoltaic devices. Several research groups around the world have developed CIGS/CdS solar cells with efficiencies larger than 15% [1] using evaporation, makin [...] g it an attractive and reliable technique for thin film deposition. Our PVD system is provided with MBE-type Knudsen cells to deposit CIGS thin films on glass/Molibdenum (Mo) substrates. The deposition conditions for each metal source have been established by doing a deposition profile of temperature data vs. growth rate by co-evaporation to obtain CIGS thin film for solar cells. Characterization of the co-evaporated CIGS thin films was performed by X-ray diffraction (X-RD), scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS) techniques. Good quality polycrystalline films were obtained as shown by X-RD patterns. SEM micrographs show films having a very uniform appearance with large grain sizes (~1 µm). Photoluminescence (PL) studies on CIGS samples with different Ga and Cu concentrations (Ga/Ga+In) = 0.25 and 0.34 and (Cu/In+Ga) = 0.83, 0.88 and 0.94) have been performed. The EDS results have shown that is possible to control very precisely the CIGS thin film composition using these Knudsen cells. Film thicknesses of ~3-4 µm, were measured with an Ambios profilemeter XP 100 stylus type. A conversion efficiency of 10.9 % has been achieved for solar cells made from the co-evaporated absorbers.

  3. Flexible Cu(In,Ga)Se2 thin-film solar cells for space application

    International Nuclear Information System (INIS)

    Thin film solar cells (TFSC) with Cu(In,Ga)Se2 (CIGS) as absorber layer have been produced on rigid glass substrates for the terrestrial market. There exist, however, different investigations for manufacturing of TFSC on flexible substrates in order to achieve very thin and highly flexible (rollable) solar cells. Besides their capability to open new terrestrial market segments, they are considered as competitive candidates for future flexible thin film space power generators compared to traditional crystalline solar cells. This paper explains the advantages of flexible TFSC for usage in space, including:-low mass and storage volume, -high power/mass ratio [>100 W/kg at array level], -high radiation resistance against proton and electron radiation and, -lower production costs. These cells can be produced on flexible conductive and insulating substrate materials and have efficiency potentials of up to 15%. We report on the current development steps to adopt the TFSC technology to space requirements as well as the first European industrial approach to the roll-to-roll production of flexible CIGS-TFSC on polyimide as substrate material. Stability issues in space environment concern not only the TFSC itself, but all system components such as interconnects, cell assembly and flexible blankets. The adhesion of the back-contact to the substrate, the emissivity control in the infrared wavelength range, the electrical contacting and interconnection as well as flexible encapsulation are currently under investigation and are discussed in the paper. The production costs for TFSC for space application can be further reduced by sharing resources for the production of flexible TFSC for the terrestrial market; namely by using both, the existing terrestrial investment in production facilities as well as the synergies in R and D

  4. Determination of optical and mechanical properties of Nb2O5 thin films for solar cells application

    International Nuclear Information System (INIS)

    Highlights: • Niobium pentoxide films were prepared by microwave assisted magnetron sputtering. • Optical and mechanical properties of Nb2O5 thin films were investigated. • The surface of thin films was homogenous, crack free and exhibited low RMS roughness. • Prepared Nb2O5 coatings were well transparent from ca., 350 nm. • Hardness of deposited coatings was ca., 7 GPa. - Abstract: In this paper investigation results of niobium pentoxide thin films deposited by microwave assisted reactive magnetron sputtering process were described. Surface of prepared coatings was examined with the aid of atomic force microscope (AFM) operating in the contact-mode and in ultra high vacuum conditions. The surface of thin films was homogenous, crack free and exhibit low root mean square (RMS) roughness of about 0.34 nm. X-ray photoelectron spectroscopy (XPS) studies were performed to determine the chemical states of the niobium at the surface of thin films. Contact angle and surface free energy were additionally investigated to examine the surface properties of the deposited coatings. Optical properties of the Nb2O5 thin films showed, that prepared coatings were well transparent from 350 nm to longer wavelength range. Based on transmission and reflection measurements the values of refractive index and extinction coefficient were determined. The antireflective coating based on Nb2O5 thin films for solar cells application was proposed. The hardness and Young's modulus measurements were performed by the nanoindentation technique. These investigations revealed that the hardness of the deposited coatings was ca., 7 GPa. Also scratch tests were applied, which have shown that the Nb2O5 thin films were scratch resistant

  5. FEM-based optical modeling of silicon thin-film tandem solar cells with randomly textured interfaces in 3D

    Science.gov (United States)

    Hammerschmidt, Martin; Lockau, Daniel; Burger, Sven; Schmidt, Frank; Schwanke, Christoph; Kirner, Simon; Calnan, Sonya; Stannowski, Bernd; Rech, Bernd

    2013-03-01

    Light trapping techniques are one of the key research areas in thin film silicon photovoltaics. Since the 1980s randomly rough textured front transparent oxides (TCOs) have been the methods of choice as light trapping strategies for thin-film devices. Light-trapping efficiency can be optimized by means of optical simulations of nano-structured solar cells. We present a FEM based simulator for 3D rigorous optical modeling of amorphous silicon / microcrystalline silicon tandem thin-film solar cells with randomly textured layer interfaces. We focus strongly on an error analysis study for the presented simulator to demonstrate the numerical convergence of the method and investigate grid and finite element degree refinement strategies in order to obtain reliable simulation results.

  6. Five roads towards increased optical absorption and high stable efficiency for thin film silicon solar cells.

    Czech Academy of Sciences Publication Activity Database

    Van??ek, Milan; Poruba, Aleš; Remeš, Zden?k; Holovský, Jakub; Purkrt, Adam; Babchenko, Oleg; Hruška, Karel; Meier, J.; Kroll, U.

    Munich : WIP-Renewable Energies, 2009 - (Sinke, W.; Ossenbrink, H.; Helm, P.), s. 2286-2289 ISBN 3-936338-25-6. [European Photovoltaic Solar Energy Conference /24./. Hamburg (DE), 21.09.2009-25.09.2009] R&D Projects: GA MŠk(CZ) 7E09057 Grant ostatní: EU FP7(XE) CP-IP 214134-2; EU FP6 ATHLET(XE) SES6-019670 Institutional research plan: CEZ:AV0Z10100521 Keywords : high stable efficiency * amorphous silicon * thin film solar cell * 3-dimensional nanostructuring * transparent conductive oxides Subject RIV: BM - Solid Matter Physics ; Magnetism http://dx.doi.org/10.4229/24thEUPVSEC2009-3BO.9.1

  7. A study of the applicability of ZnO thin-films as anti-reflection coating on Cu2ZnSnS4 thin-films solar cell

    International Nuclear Information System (INIS)

    Transparent ZnO thin-films are prepared using the RF magnetron sputtering and spray pyrolysis techniques on the glass substrates. Reflectance spectra and thin films heights are measured using spectrophotometer and stylus surface profiler, respectively. Measured optical data is used for investigating the effect of the ZnO prepared by above two processes on the performance of Cu2ZnSnS4 (CZTS) thin films solar cell (TFSC). One dimensional simulation approach is considered using the simulation program, SCAPS. External quantum efficiency and J-V characteristics of CZTS TFSC is simulated on the basis of optical reflectance data of ZnO films with and without ZnO thin-films as antireflection coating (ARC). Study shows that ARC coated CZTS TFSC provides a better fill factor (FF) as compared to other ARC material such as MgF2. Sprayed ZnO thin-films as ARC show comparable performance with the sputtered samples.

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

    International Nuclear Information System (INIS)

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

  9. Polypyrrole thin films decorated with copper nanostructures as counter electrode for dye-sensitized solar cells

    Science.gov (United States)

    Ghani, Sheeba; Sharif, Rehana; Bashir, Saima; Zaidi, Azhar A.; Rafique, M. S.; Ashraf, Ayesha; Shahzadi, Shamaila; Rafique, Shaista; Kamboh, Afzal H.

    2015-05-01

    A two-step electrochemical polymerization method for the fabrication of polypyrrole (PPY) thin films decorated with copper nanostructures on a stainless steel has been employed. The PPY film thickness affects the size, shape, and the number density of the copper nanostructures and provides an easy approach to control the morphology of these nanostructures. SEM images show nanorod like structures of copper on 200 nm PPY film. By employing this composite film as counter electrode (CE), a dye-sensitized solar cell (DSSC) achieves a conversion efficiency of 7.42%, which is greater than Pt CE based DSSC (5.63%). The superior photovoltaic efficiency for the Cu-PPY film is attributed to unique porous PPY thin film and copper nanorods structure that leads to higher cathodic current density (5.38 mA/cm2), large electrocatalytic activity, and small charge transfer resistance(1.92 ? cm-2). Therefore, Cu-PPY composite can be considered a competitive and promising CE material with the traditional and expensive Pt CE, for large-scale DSSCs production.

  10. Interfacial alkali diffusion control in chalcopyrite thin-film solar cells.

    Science.gov (United States)

    Ishizuka, Shogo; Yamada, Akimasa; Fons, Paul J; Shibata, Hajime; Niki, Shigeru

    2014-08-27

    Alkali elements, specifically sodium (Na), are key materials to enhance the energy conversion efficiencies of chalcopyrite and related thin-film photovoltaic solar cells. Recently, the effect of potassium (K) has also attracted attention because elemental K has unique effects different from Na as well as a similar beneficial effect in improving device performance. In this study, the control of selective alkali K and Na diffusion into chalcopyrite thin-films from soda-lime glass substrates, which serve as the monolithic alkali source material and contain both K and Na, is demonstrated using ternary CuGaSe2. Elemental K is found to be incorporated in the several ten nanometer thick Cu-deficient region, which is formed on the CuGaSe2 film surface, while Na is ejected, although both K and Na diffuse from the substrate to the CuGaSe2 film surface during growth. The alkali [K]/[Na] concentration ratio in the surface region of CuGaSe2 films strongly depends on the film structure and can be controlled by growth parameters under the same substrate temperature conditions. The results we present here offer new concepts necessary to explore and develop emerging new chalcopyrite and related materials and optimize their applications. PMID:25004458

  11. Basella alba rubra spinach pigment-sensitized TiO2 thin film-based solar cells

    Science.gov (United States)

    Gokilamani, N.; Muthukumarasamy, N.; Thambidurai, M.; Ranjitha, A.; Velauthapillai, Dhayalan

    2015-03-01

    Nanocrystalline TiO2 thin films have been prepared by sol-gel dip coating method. The X-ray diffraction results showed that TiO2 thin films annealed at 400, 450 and 500 °C are of anatase phase and the peak corresponding to the (101) plane is present in all the samples. The grain size of TiO2 thin films was found to increase with increasing annealing temperature. The grain size is found to be 20, 25 and 33 nm for the films annealed at 400, 450 and 500 °C. The structure of the TiO2 nanocrystalline thin films have been examined by high-resolution transmission electron microscope, Raman spectroscopy and FTIR spectroscopy. TiO2 thin films were sensitized by natural dyes extracted from basella alba rubra spinach. It was found that the absorption peak of basella alba rubra extract is at about 665 nm. The dye-sensitized TiO2-based solar cell sensitized using basella alba rubra exhibited a J sc of 4.35 mA cm-2, V oc of 0.48 V, FF of 0.35 and efficiency of 0.70 %. Natural dyes as sensitizers for dye-sensitized solar cells are promising because of their environmental friendliness, low-cost production and fully biodegradable.

  12. Light-trapping and antireflective coatings for amorphous Si-based thin film solar cells

    Science.gov (United States)

    Voroshilov, Pavel M.; Simovski, Constantin R.; Belov, Pavel A.; Shalin, Alexander S.

    2015-05-01

    In this paper, we study the efficiency of several types of all-dielectric, non-resonant, antireflection, and light-trapping coatings for the enhancement of photovoltaic absorption in thin-film silicon solar cells. We compare the enhancement of the photovoltaic absorption offered by a square array of nano-pillar shaped voids in the dielectric covering of the cell with that granted by a flat blooming layer, and a densely packed array of dielectric nanospheres. We optimize these coatings and show that the newly proposed nanostructure allows a significant increase of the photovoltaic absorption. The dependence of antireflection and light-trapping properties on the angle of incidence is numerically investigated, and it is shown that the array of voids keeps optimal also after averaging over the incidence angles.

  13. Research on polycrystalline thin-film CuGaInSe[sub 2] solar cells

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-11-01

    This report describes research to fabricate high-efficiency CdZnS/CuInGaSe[sub 2] (CIGS) thin-film solar cells, and to develop improved transparent conductor window layers such as ZnO. A specific technical milestone was the demonstration of an air mass (AM) 1.5 global, 13% efficient, 1-cm[sup 2]-total-area CIGS thin-film solar cell. Our activities focused on three areas. First, a CIGS deposition: system was modified to double its substrate capacity, thus increasing throughput, which is critical to speeding the process development by providing multiple substrates from the same CIGS run. Second, new tooling was developed to enable an investigation of a modified aqueous CdZnS process. The goal was to improve the yield of this critical step in the device fabrication process. Third, our ZnO sputtering system was upgraded to improve its reliability, and the sputtering parameters were further optimized to improve its properties as a transparent conducting oxide. The characterization of the new CIGS deposition system substrate fixturing was completed, and we produced good thermal uniformity and adequately high temperatures for device-quality CIGS deposition. Both the CIGS and ZnO deposition processes were refined to yield a ZnO//Cd[sub 0.82]Zn[sub 0.18]S/CuIn[sub 0.80]Ga[sub 0.20]Se[sub 2] cell that was verified at NREL under standard testing conditions at 13.1% efficiency with V[sub oc] = 0.581 V, J[sub sc] = 34.8 mA/cm[sup 2], FF = 0.728, and a cell area of 0.979 cm[sup 2].

  14. Thin film solar energy collector

    Science.gov (United States)

    Aykan, Kamran (Monmouth Beach, NJ); Farrauto, Robert J. (Westfield, NJ); Jefferson, Clinton F. (Millburn, NJ); Lanam, Richard D. (Westfield, NJ)

    1983-11-22

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

  15. Heterojunction solar cells with integrated Si and ZnO nanowires and a chalcopyrite thin film

    Energy Technology Data Exchange (ETDEWEB)

    Karaagac, Hakan, E-mail: hkaraagac@ucdavis.edu [Department of Electrical and Computer Engineering, University of California at Davis, Davis, CA 95616 (United States); Department of Physics, Middle East Technical University, 06531 Ankara (Turkey); Parlak, Mehmet [Department of Physics, Middle East Technical University, 06531 Ankara (Turkey); Yengel, Emre; Islam, M. Saif [Department of Electrical and Computer Engineering, University of California at Davis, Davis, CA 95616 (United States)

    2013-06-15

    ZnO nanowires (NWs) have been successfully synthesized using a hydrothermal technique on both glass and silicon substrates initially coated with a sputtered ZnO thin film layer. Varying ZnO seed layer thicknesses were deposited to determine the effect of seed layer thickness on the quality of ZnO NW growth. The effect of growth time on the formation of ZnO NWs was also studied. Experimental results show that these two parameters have an important effect on formation, homogeneity and vertical orientation of ZnO NWs. Silicon nanowires were synthesized by a Ag-assisted electroless etching technique on an n-type Si (100) wafer. SEM observations have revealed the formation of vertically-aligned Si NWs with etching depth of ?700 nm distributed over the surface of the Si. An electron-beam evaporated chalcopyrite thin film consisting of p-type AgGa{sub 0.5}In{sub 0.5}Se{sub 2} with ?800 nm thickness was deposited on the n-type ZnO and Si NWs for the construction of nanowire based heterojunction solar cells. For the Si NW based solar cell, from a partially illuminated area of the solar cell, the open-circuit voltage, short-circuit current density, fill factor and power conversion efficiency were 0.34 V, 25.38 mA cm{sup ?2}, 63% and 5.50%, respectively. On the other hand, these respective parameters were 0.26 V, 3.18 mA cm{sup ?2}, 35% and 0.37% for the ZnO NW solar cell. - Highlights: • ZnO nanowires using hydrothermal technique have been synthesized successfully. • Silicon nanowires were synthesized by Ag-assisted electroless etching technique. • A p-type AGIS was deposited on the n-type ZnO and n-Si NWs for nanowire based solar cells. • Power conversion efficiency of 5.50% was obtained for Si nanowires based solar cell.

  16. 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)

  17. Dip coated nanocrystalline CdZnS thin films for solar cell application

    Science.gov (United States)

    Dongre, J. K.; Chaturvedi, Mahim; Patil, Yuvraj; Sharma, Sandhya; Jain, U. K.

    2015-07-01

    Nanocrystalline cadmium sulfide (CdS) and zinc cadmium sulfide (ZnCdS) thin films have been grown via simple and low cost dip coating technique. The prepared films are characterized by X-ray diffraction (XRD), atomic force microscopic (AFM) and UV-VIS spectrophotometer techniques to reveal their structural, morphological and optical properties. XRD shows that both samples grown have zinc blende structure. The grain size is calculated as 6.2 and 8 nm using Scherrer's formula. The band gap value of CdS and CdZnS film is estimated to be 2.58 and 2.69 eV respectively by UV-vis spectroscopy. Photoelectrochemical (PEC) investigations are carried out using cell configuration as n-CdZnS/(1M NaOH + 1M Na2S + 1M S)/C. The photovoltaic output characteristic is used to calculate fill-factor (FF) and solar conversion efficiency (?).

  18. Spin Coated Plasmonic Nanoparticle Interfaces for Photocurrent Enhancement in Thin Film Si Solar Cells

    CERN Document Server

    Israelowitz, Miriam; Cong, Tao; Sureshkumar, Radhakrishna

    2013-01-01

    Nanoparticle (NP) arrays of noble metals strongly absorb light in the visible to infrared wavelengths through resonant interactions between the incident electromagnetic field and the metal's free electron plasma. Such plasmonic interfaces enhance light absorption and photocurrent in solar cells. We report a cost effective and scalable room temperature/pressure spin-coating route to fabricate broadband plasmonic interfaces consisting of silver NPs. The NP interface yields photocurrent enhancement (PE) in thin film silicon devices by up to 200% which is significantly greater than previously reported values. For coatings produced from Ag nanoink containing particles with average diameter of 40 nm, an optimal NP surface coverage of 7% was observed. Scanning electron microscopy of interface morphologies revealed that for low surface coverage, particles are well-separated, resulting in broadband PE. At higher surface coverage, formation of particle strings and clusters caused red-shifting of the PE peak and a narro...

  19. Numerical simulation of plasmonic light trapping in thin-film Si solar cells: surface coverage effect

    Science.gov (United States)

    Ji, Alok; Sharma, Richa; Pathak, Hardik; Pathak, Nilesh Kumar; Sharma, R. P.

    2015-06-01

    Nobel metal nanoparticles support localised surface plasmonic modes. When a NP is placed in the vicinity of another nanostructure in the presence of an external field, there is a coupling between these individual modes resulting in a wide tunable resonant response which finds a variety of applications in various domains of physics and biology. The communication between these 2D NP arrays and their electromagnetic response can be controlled by the choice of material, geometry, size, interparticle distance and its surrounding matrix. In the present article, we study in detail the electromagnetic response of these talking nanostructure systems, their tuneability with respect to various parameters and scope of the optimization which may be applied for a desired application, for example to improve the read response of thin film plasmonic solar cell.

  20. Double AAO nanogratings for broad spectrum absorption enhancement in thin film Si solar cells

    Science.gov (United States)

    Qin, F. F.; Zhang, H. M.; Wang, C. X.; Zhang, J. J.; Guo, C.

    2015-12-01

    In this paper, we presented a double light trapping structure containing anodic aluminum oxide (AAO) nanogratings on both the surface and rear of thin film crystalline silicon (c-Si) solar cell. Finite difference time domain (FDTD) method was used to study the light absorption enhancement of this design. Simulation results show that, the double light trapping structure can highly increase the light absorption in the wavelengths from 280 to 1100 nm. The relative enhancement of short-circuit current density (Jsc) in this situation is 137%. Besides, the double light trapping structure can highly reduce the influence of incident angle on light absorption. The relative position of AAO pore on the surface and rear has very little influence on light trapping.

  1. Defects of a-Si Thin-Film Solar Cells Detected by Transmission Photothermal Radiometric Imaging

    Science.gov (United States)

    Yan, Laijun; Gao, Chunming; Zhao, Binxing; Sun, Qiming; Liu, Lixian; Huan, Huiting

    2015-06-01

    The photothermal radiometry (PTR) technique is an effective non-destructive testing technique for detecting defects in materials. In this paper, a piece of commercial amorphous silicon (a-Si) thin-film solar cells with some artificial mechanical defects has been investigated by the transmission PTR imaging system. Firstly, a simplified analytical expression of a normalized transmission PTR signal was employed to characterize defects. Secondly, the corresponding experimental system has been set-up for obtaining several thermal images of the sample. Thirdly, different kinds of defects have been analyzed and identified by the thermal images. The results show that not only the artificial mechanical defects on the sample can be detected, but also some defects occurring in the manufacturing process can be detected by the transmission PTR imaging system.

  2. Directly patterned TiO2 nanostructures for efficient light harvesting in thin film solar cells

    Science.gov (United States)

    Ram, Sanjay K.; Rizzoli, Rita; Desta, Derese; Jeppesen, Bjarke R.; Bellettato, Michele; Samatov, Ivan; Tsao, Yao-Chung; Johannsen, Sabrina R.; Neuvonen, Pekka T.; Pedersen, Thomas Garm; Pereira, Rui N.; Pedersen, Kjeld; Balling, Peter; Nylandsted Larsen, Arne

    2015-09-01

    A novel, scalable, and low-cost strategy for fabricating sub-wavelength scale hierarchical nanostructures by direct patterning of TiO2 nanoparticles on glass substrates is reported. Two nanostructural designs of light-trapping back-surface reflectors (BSR) have been fabricated for increasing the photon-harvesting properties of thin-film solar cells: a quasi-periodic nano-crater design and a random nano-bump design. The efficient light-scattering properties of the nano-crater design over a broad wavelength range are demonstrated by the measured haze factor being larger than 40% at wavelengths (~700?nm) near the band edge of amorphous silicon (a-Si:H). The a-Si:H-based n-i-p solar cell fabricated with an only ~200?nm thick absorber layer on the nano-crater BSR shows a short-circuit current density (J sc) of ~16.1 mA cm-2 representing a 28% enhancement compared to the cell deposited on a non-textured flat substrate. Measurements of the external quantum efficiency of the cell fabricated on the quasi-periodic nano-crater surface at long wavelengths, ???>??700?nm, demonstrate an increase of a factor of 5 relative to that of a flat reference solar cell. The theoretical modeling results of optical absorption corroborate well with the experimental findings and are used to identify the volumes of strong optical absorption in the a-Si:H active layer of the textured BSR devices.

  3. Overview and Challenges of Thin Film Solar Electric Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Ullal, H. S.

    2008-12-01

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

  4. ?-FeSi2 as the bottom absorber of triple-junction thin-film solar cells: A numerical study

    International Nuclear Information System (INIS)

    Using ?-FeSi2 as the bottom absorber of triple-junction thin-film solar cells is investigated by a numerical method for widening the long-wave spectral response. The presented results show that the ?-FeSi2 subcell can contribute 0.273 V of open-circuit voltage to the a-Si/?c-Si/?-FeSi2 triple-junction thin-film solar cell. The optimized absorber thicknesses for a-Si, ?c-Si, and ?-FeSi2 subcells are 260 nm, 900 nm, and 40 nm, respectively. In addition, the temperature coefficient of the conversion efficiency of the a-Si/?c-Si/?-FeSi2 cell is ?0.308%/K, whose absolute value is only greater than that of the a-Si subcell. This result indicates that the a-Si/?c-Si/?-FeSi2 triple-junction solar cell has a good temperature coefficient. As a result, using ?-FeSi2 as the bottom absorber can improve the thin-film solar cell performance, and the a-Si/?c-Si/?-FeSi2 triple-junction solar cell is a promising structure configuration for improving the solar cell efficiency

  5. Back surface studies of Cu(In,Ga)Se2 thin film solar cells

    Science.gov (United States)

    Simchi, Hamed

    Cu(In,Ga)Se2 thin film solar cells have attracted a lot of interest because they have shown the highest achieved efficiency (21%) among thin film photovoltaic materials, long-term stability, and straightforward optical bandgap engineering by changing relative amounts of present elements in the alloy. Still, there are several opportunities to further improve the performance of the Cu(In,Ga)Se2 devices. The interfaces between layers significantly affect the device performance, and knowledge of their chemical and electronic structures is essential in identifying performance limiting factors. The main goal of this research is to understand the characteristics of the Cu(In,Ga)Se2-back contact interface in order to design ohmic back contacts for Cu(In,Ga)Se2-based solar cells with a range of band gaps and device configurations. The focus is on developing either an opaque or transparent ohmic back contact via surface modification or introduction of buffer layers in the back surface. In this project, candidate back contact materials have been identified based on modeling of band alignments and surface chemical properties of the absorber layer and back contact. For the first time, MoO3 and WO 3 transparent back contacts were successfully developed for Cu(In,Ga)Se 2 solar cells. The structural, optical, and surface properties of MoO 3 and WO3 were optimized by controlling the oxygen partial pressure during reactive sputtering and post-deposition annealing. Valence band edge energies were also obtained by analysis of the XPS spectra and used to characterize the interface band offsets. As a result, it became possible to illuminate of the device from the back, resulting in a recently developed "backwall superstrate" device structure that outperforms conventional substrate Cu(In,Ga)Se2 devices in the absorber thickness range 0.1-0.5 microm. Further enhancements were achieved by introducing moderate amounts of Ag into the Cu(In,Ga)Se2 lattice during the co-evaporation method resulting in a 9.7% cell (with 0.3 microm thickness) which has the highest efficiency reported for ultrathin CIGS solar cells to date. In addition, sulfized back contacts including ITO-S and MoS 2 are compared. Interface properties of different contact layers with (Ag,Cu)(In,Ga)Se2 absorber layers with various Ga/(Ga+In) and Ag/(Ag+Cu) ratios are discussed based on the XPS analysis and thermodynamics of reactions.

  6. Electronic grain boundary properties in polycrystalline Cu(In,Ga)Se2 semiconductors for thin film solar cells

    International Nuclear Information System (INIS)

    Solar cells based on polycrystalline Cu(In,Ga)Se2 (CIGSe) thin film absorbers reach the highest energy conversion efficiency among all thin film solar cells. The record efficiency is at least partly attributed to benign electronic properties of grain boundaries (GBs) in the CIGSe layers. However, despite a high amount of research on this phenomenon the underlying physics is not sufficiently understood. This thesis presents an elaborate study on the electronic properties of GBs in CIGSe thin films. Kelvin probe force microscopy (KPFM) was employed to investigate the electronic properties of GBs in dependence of the Ga-content. Five CIGSe thin lms with various Ga-contents were grown by means of similar three stage co-evaporation processes. Both as grown as well as chemically treated (KCN etched) thin films were analyzed. The chemical treatment was employed to remove surface oxides. No difference in electronic GB properties was found with or without the chemical treatment. Therefore, we conclude that a moderate surface oxidation does not alter the electronic properties of GBs. In general, one can observe significant variations of electronic potential barriers at GBs. Under consideration of the averaging effect of the work function signal of nanoscale potential distributions in KPFM measurements which was quantified in the course of this thesis both positive and negative potential barriers in a range between ?-350 mV and ?+450 mV were detected. Additionally, variations in the defect densities at GBs between ?3.1 x 1011 cm-2 and ?2.1 x 1012 cm-2 were found. However, no correlation between the electronic properties of GBs and the Ga-content of CIGSe thin films was discovered. Consequently, one cannot explain the drop in device efficiency observed for CIGSe thin film solar cells with a high Ga-content by a change of the electronic properties of GBs. Combined KPFM and electron backscatter diffraction measurements were employed for the first time on CIGSe thin films to gather complementary information about both the structural and electronic properties of individual GBs. With the help of this information it was possible to investigate the interrelationship between the symmetry and the electronic potential barrier of GBs. We could reveal that highly symmetric ?3 GBs have a lower probability to possess a charged potential barrier than lower symmetric non-?3 GBs. The assumption of a general symmetry-dependence of the electronic properties of GBs in CIGSe, i.e. a correlation between the particular symmetry of a GB and its potential barrier that is also valid for GBs with symmetries lower than ?3, could help to explain the large variations of potential barriers observed at GBs in polycrystalline CIGSe thin films.

  7. Characteristics of in-substituted CZTS thin film and bifacial solar cell.

    Science.gov (United States)

    Ge, Jie; Chu, Junhao; Jiang, Jinchun; Yan, Yanfa; Yang, Pingxiong

    2014-12-10

    Implementing bifacial photovoltaic devices based on transparent conducting oxides (TCO) as the front and back contacts is highly appealing to improve the efficiency of kesterite solar cells. The p-type In substituted Cu2ZnSnS4 (CZTIS) thin-film solar cell absorber has been fabricated on ITO glass by sulfurizing coelectroplated Cu-Zn-Sn-S precursors in H2S (5 vol %) atmosphere at 520 °C for 30 min. Experimental proof, including X-ray diffraction, Raman spectroscopy, UV-vis-NIR transmission/reflection spectra, PL spectra, and electron microscopies, is presented for the interfacial reaction between the ITO back contact and CZTS absorber. This aggressive reaction due to thermal processing contributes to substitutional diffusion of In into CZTS, formation of secondary phases and electrically conductive degradation of ITO back contact. The structural, lattice vibrational, optical absorption, and defective properties of the CZTIS alloy absorber layer have been analyzed and discussed. The new dopant In is desirably capable of improving the open circuit voltage deficit of kesterite device. However, the nonohmic back contact in the bifacial device negatively limits the open circuit voltage and fill factor, evidencing by illumination-/temperature-dependent J-V and frequency-dependent capacitance-voltage (C-V-f) measurements. A 3.4% efficient solar cell is demonstrated under simultaneously bifacial illumination from both sides of TCO front and back contacts. PMID:25340540

  8. CIGS Thin Films for Cd-Free Solar Cells by One-Step Sputtering Process

    Science.gov (United States)

    Xiang, Jun; Huang, Xing; Lin, Gengqi; Tang, Jiang; Ju, Chen; Miao, Xiangshui

    2014-07-01

    Cu(In1- x Ga x )Se2 (CIGS) thin films were deposited by a one-step radio frequency (RF) magnetron sputtering process using a quaternary CIGS target. The influence of substrate temperature on the composition, structure, and optical properties of the CIGS films was investigated. All the CIGS films exhibited the chalcopyrite structure with a preferential orientation along the (112) direction. The CIGS film deposited at 623 K showed significant improvement in film crystallinity and surface morphology compared to films deposited at 523 and 573 K. To simplify the manufacturing procedure of solar cells and avoid the use of the toxic element Cd, the properties of ZnS films prepared by RF sputtering were also investigated. The results revealed that the sputtered ZnS film exhibits good lattice matching with the sputtered CIGS film with significantly lower optical absorption loss. Finally, all-sputtered Cd-free CIGS-based heterojunction solar cells with the structure SLG/Mo/CIGS/ZnS/AZO/Al grids were fabricated without post-selenization. Furthermore, the results demonstrated the feasibility of using a full sputtering process for the fabrication of Cd-free CIGS-based solar cell.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ledinský, M., E-mail: ledinsky@fzu.cz [Laboratory of Nanostructures and Nanomaterials, Institute of Physics, Academy of Sciences of the Czech Republic, v. v. i., Cukrovarnická 10, 162 00 Prague (Czech Republic); Photovoltaics and Thin Film Electronics Laboratory, Institute of Microengineering (IMT), École Polytechnique Fédérale de Lausanne (EPFL), Rue de la Maladière 71b, CH-2000 Neuchâtel (Switzerland); Moulin, E.; Bugnon, G.; Meillaud, F.; Ballif, C. [Photovoltaics and Thin Film Electronics Laboratory, Institute of Microengineering (IMT), École Polytechnique Fédérale de Lausanne (EPFL), Rue de la Maladière 71b, CH-2000 Neuchâtel (Switzerland); Ganzerová, K.; Vetushka, A.; Fejfar, A. [Laboratory of Nanostructures and Nanomaterials, Institute of Physics, Academy of Sciences of the Czech Republic, v. v. i., Cukrovarnická 10, 162 00 Prague (Czech Republic)

    2014-09-15

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

  10. Dyadic Green’s functions of thin films: Applications within plasmonic solar cells

    DEFF Research Database (Denmark)

    Jung, Jesper; SØndergaard, Thomas

    2011-01-01

    Optimization and design of silicon solar cells by exploiting light scattering frommetal nanoparticles to increase the efficiency is addressed in the small particle limit from a fundamental point of view via the dyadic Green’s function formulation. Based on the dyadic Green’s function (Green’s tensor) of a three-layer geometry, light scattering from electric point dipoles (representing small metal scatterers) located within a thin layer sandwiched between a substrate and a superstrate is analyzed. Starting from the full dyadic Green’s function we derive analytical near- and far-field approximations. The far-field approximations enable efficient, exact, and separate evaluation of light scattering into waves that propagate in the substrate or the superstrate. Based on the near-field approximation we present a semianalytical expression for the total near-field absorption in the substrate. The theoretical approach is used to analyze realistic configurations for plasmon-assisted silicon solar cells. We showthat by embedding metal nanoscatterers in a thin film with a high refractive index (rutile TiO2 with n ? 2.5) on top of the silicon, the fraction of scattered light that couples into the solar cell can become larger than 96%, and an optical path length enhancement of more than 100 can be achieved.

  11. Microcrystalline silicon absorber layers prepared at high deposition rates for thin-film tandem solar cells

    Directory of Open Access Journals (Sweden)

    Michard S.

    2013-12-01

    Full Text Available We have investigated high deposition rate processes for the fabrication of thin-film silicon tandem solar cells. Microcrystalline silicon absorber layers were prepared under high pressure depletion conditions at an excitation frequency of 81.36 MHz. The deposition rate was varied in the range of 0.2 nm/s to 3.2 nm/s by varying the deposition pressure and deposition power for given electrode spacings. The silane-to-hydrogen process gas mixture was adjusted in each case to prepare optimum phase mixture material. The performance of these tandem solar cells was investigated by external quantum efficiency and current-voltage measurements under AM1.5 illumination before and after 1000 h of light degradation. Up to deposition rates of 0.8 nm/s for the microcrystalline silicon absorber layer high quality tandem solar cells with an initial efficiency of 10.9% were obtained (9.9% stabilized efficiency after 1000 h of light degradation.

  12. Surface and interface characterization of thin-film silicon solar cell structures

    Energy Technology Data Exchange (ETDEWEB)

    Gerlach, Dominic

    2013-02-21

    The properties of Si thin films for solar cells, the interaction with different substrates and the influence of dopants are examined with synchrotron based x-ray spectroscopy - primarily X-ray emission spectroscopy (XES) and hard X-ray photoelectron spectroscopy (HAXPES). The films are studied as-deposited (i.e., amorphous, a-Si) and after conversion into polycrystalline (poly-Si) employing solid phase crystallization (SPC). Si L{sub 2,3} XES spectra of thin-film Si samples can be described by a superposition of a-Si and monocrystalline Si-wafer (c-Si) reference spectra. According to a quantification based on that superposition principle, none of the investigated samples are completely crystallized - a measurable a-Si component always remains (5-20 %) regardless of deposition and treatment conditions. Based on additional results from electron back scattering diffraction different models are developed which may explain this finding. According to these models, the remnant a-Si component can be attributed to amorphous/disordered material at the grain boundaries. Using one of these models, the thickness of this grain-surrounding material s could be approximated to be (1.5 {+-} 0.5) nm. Further investigations of the SPC process reveal a faster crystallization for boron-doped samples, and a slower crystallization for phosphorous-doped samples, when compared to the crystallization of undoped a Si:H thin films. The peculiarities of B K XES spectra (and observed changes upon SPC) indicate that boron could act as a nucleation center promoting crystallization. Si L{sub 2,3} XES spectra of a-Si:H and P-doped poly-Si exhibit spectral features above the valence band maximum at 100 eV that could be attributed to a-Si defect states and n{sup +}-dopant states, respectively. The SPC crystallization velocity of Si thin films on ZnO:Al/glass is found to be faster than that on SiNx/glass substrate. Multiple indications for oxidization at the poly-Si/ZnO:Al interface are found based on our Si L{sub 2,3} XES analysis. Spatially resolved x-ray photoelectron spectroscopy data support this and even suggest the formation of sub-oxides or zinc silicate as an interface species. The electronic structure of the buried a-SiO{sub x}:H(B)/ZnO:Al and {mu}c-Si:H(B)/ZnO:Al interfaces are unraveled with ''depth resolved'' hard x-ray photoelectron spectroscopy. A surface band bending limited to the very surface of the silicon layers is found. The valence band maxima for the Si cover layers and the ZnO:Al TCO are determined and interface induced band bending for both interfaces are derived. At the a-SiO{sub x}:H(B)/ZnO:Al interface a tunnel barrier of (0.22 {+-} 0.31) eV and at {mu}c-Si:H(B)/ZnO:Al interface a tunnel barrier of (-0.08 {+-} 0.31) eV is determined. This explains a previously empirically found solar cell efficiency increase produced by introducing a {mu}c-Si:H(B) buffer layer between an a-Si p-i-n cell and the ZnO:Al/glass substrate.

  13. Copper gallium diselenide thin film absorber growth for solar cell device fabrication

    Science.gov (United States)

    Kaczynski, Ryan

    2007-12-01

    A custom-built migration-enhanced epitaxy reactor originally optimized for CuInSe2 (CIS) deposition was modified to grow gallium-containing compound semiconductor thin films, such as CuGaSe2 (CGS) and CuIn1-xGaxSe2 (CIGS). The addition of gallium allows for the manufacturing of solar cell absorber layers with wider band gaps. Three distinct growth recipes under several growth temperatures and a wide range of metal-composition ratios are used to deposit polycrystalline CGS thin films. The surface morphology of gallium-rich films is typically very uniform, with long needle-like grains when grown by the first recipe, a constant copper-rate process. In contrast, copper-rich films grown by this same recipe or by a modified three-stage process have island structures with very large grains embedded in a matrix region that possesses small grains. The surface morphology becomes more uniform and the grains in the matrix region become larger when a higher growth temperature is used. The third recipe, an emulated three-stage process, does not produce films with an island-matrix structure, and the grains are uniformly large. The highest conversion efficiency achieved for solar cells based on CGS is 5.3%, delivered by a copper-rich absorber deposited at the highest sustainable growth temperature of 491°C. This device has a large fill factor of 66%, but the open-circuit voltage of 0.48 V is lower than what is expected from a wide band-gap absorber. A set of CIGS solar cells was completely fabricated and characterized in-house. This led to the most efficient device produced from an absorber grown in our reactor, in the form of a 9% CIS solar cell featuring a one-micron film deposited at 491°C. Finally, a dynamic reactor model was created to describe the deposition environment in our epitaxial reactor. All relevant physical features are incorporated, including the cyclic motion of a rotating platen and the spatial distribution of the flux produced by three metal effusion sources. Reaction occurs under an excess of selenium, and operational variables such as rotational speed and melt height can be simulated. The outputs are predicted film thickness and composition. Further work is proposed to identify the values of adjustable sticking coefficients using experimental data.

  14. Modelling of two-and four-terminal thin-film silicon tandem solar cells

    International Nuclear Information System (INIS)

    We have performed semi-empirical modelling of amorphous silicon/microcrystalline silicon thin-film solar cells in tandem optical configuration, under series (two-terminal) and independent (four-terminal) electrical connection. The four-terminal connection relaxes the constraint of current matching between the cells. Computer simulations indicate an increase in maximum initial efficiency from 10.0% (two-terminal) to 10.8% (four-terminal). Following degradation of the amorphous silicon top-cell the figures are 8.5% and 9.8% respectively, with an optimum top-cell absorber layer thickness in four-terminal connection of 150 nm. Changes in solar spectral quality have been simulated by applying weighted spectra, and improvements in efficiency favouring four-terminal connection occur under red- and blue-rich conditions. However, these typically convey only a small fraction of the total annual insolation, and gains of 5% or less in annual electrical output are predicted. Possible increased optical and electrical losses due to additional contact layers in four-terminal connection are not taken into account.

  15. Influence of rare earth elements on photovoltaic properties of nanocrystalline silicon thin film solar cells

    Science.gov (United States)

    Bariakhtar, Irina; Naughton, M.; Burns, M.; Yakimenko, Yu.; Ivashchuk, A.; Koval, V.; Yasievich, Yu.; Dusheyko, M.; CRDF/Solar Thechnology Collaboration

    2014-03-01

    The silicon nanocomposites (nc-Si) with rare earth elements (REE) are the new materials used in optoelectronics. The presence of REE is the cause of the photoluminescence in a silicon nanomaterial and is well studied. However, the introduction of REE impurities into a silicon nanocomposite with the semiconductor matrix (?-Si) appears to be a promising new technology, since such materials can be used in photosensors and thin-film solar cells. It is known that the RE metal impurities can significantly improve transport properties of the material. Such methods have been already used in some solar technologies. Additionally, they can improve photosensitive properties of a material and the REEs with a double valence create the optical impurity centers of a different nature. Finally, some RE ions, e.g. Eu, can effectively absorb UV radiation due to the specific structure of their energy levels. In this presentation, we discuss the influence of the REE on the photovoltaic properties of the nanocrystalline silicon solar cells, their optical characteristics and energy adsorption properties This work is supported in part by the CRDF Grant UKP2-7040-KV-11.

  16. Nanostructured p-type CZTS thin films prepared by a facile solution process for 3D p-n junction solar cells.

    Science.gov (United States)

    Park, Si-Nae; Sung, Shi-Joon; Sim, Jun-Hyoung; Yang, Kee-Jeong; Hwang, Dae-Kue; Kim, JunHo; Kim, Gee Yeong; Jo, William; Kim, Dae-Hwan; Kang, Jin-Kyu

    2015-07-01

    Nanoporous p-type semiconductor thin films prepared by a simple solution-based process with appropriate thermal treatment and three-dimensional (3D) p-n junction solar cells fabricated by depositing n-type semiconductor layers onto the nanoporous p-type thin films show considerable photovoltaic performance compared with conventional thin film p-n junction solar cells. Spin-coated p-type Cu2ZnSnS4 (CZTS) thin films prepared using metal chlorides and thiourea show unique nanoporous thin film morphology, which is composed of a cluster of CZTS nanograins of 50-500 nm, and the obvious 3D p-n junction structure is fabricated by the deposition of n-type CdS on the nanoporous CZTS thin films by chemical bath deposition. The photovoltaic properties of 3D p-n junction CZTS solar cells are predominantly affected by the scale of CZTS nanograins, which is easily controlled by the sulfurization temperature of CZTS precursor films. The scale of CZTS nanograins determines the minority carrier transportation within the 3D p-n junction between CZTS and CdS, which are closely related with the photocurrent of series resistance of 3D p-n junction solar cells. 3D p-n junction CZTS solar cells with nanograins below 100 nm show power conversion efficiency of 5.02%, which is comparable with conventional CZTS thin film solar cells. PMID:26061271

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

    Science.gov (United States)

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

    2015-10-01

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

  18. Fabrication of CZTS-based thin film solar cells using all-solution processing and pulsed light crystallization

    Science.gov (United States)

    Munn, Carson; Haran, Shivan; Seok, Ilwoo

    2013-04-01

    Solar cells can be produced using thin film based photovoltaic materials; these are highly efficient with respect to their optical properties and manufacturing cost. The prospective thin film solar cells are composed of Copper, Zinc, Tin, and Sulfide, or `CZTS', this contains chemicals, which are both earth-abundant and non-toxic. The all-solution based process is investigated which is on a single-step electro-chemistry deposition that provides all constituents from the same electrolyte. This investigation was successful in our research group with a high degree of success and a photo-thermal energy driven sintering process that forms a CZTS material from the as-deposited chemicals was added. This enables the as-deposited chemicals to be covalently bonded and crystallized without using a costly vacuum process. In post-heat treatment, a homemade intense pulsed lighting (IPL) system was utilized for rapid thermal annealing. The successful deposition of the CZTS thin film was then evaluated and analyzed using cyclic voltammetry (CV), SEM/EDAX, and XRD. It has been concluded that photovoltaic thin film fabrication is truly comparable to the conventional deposition and annealing methods in terms of photovoltaic efficiency and cost-effectiveness.

  19. Electrophoretic deposited TiO(2) pigment-based back reflectors for thin film solar cells.

    Science.gov (United States)

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

    2015-02-01

    Highly reflective coatings with strong light scattering effect have many applications in optical components and optoelectronic devices. This work reports titanium dioxide (TiO(2)) pigment-based reflectors that have 2.5 times higher broadband diffuse reflection than commercially produced aluminum or silver based reflectors and result in efficiency enhancements of a single-junction amorphous Si solar cell. Electrophoretic deposition is used to produce pigment-based back reflectors with high pigment density, controllable film thickness and site-specific deposition. Electrical conductivity of the pigment-based back reflectors is improved by creating electrical vias throughout the pigment-based back reflector by making holes using an electrical discharge / dielectric breakdown approach followed by a second electrophoretic deposition of conductive nanoparticles into the holes. While previous studies have demonstrated the use of pigment-based back reflectors, for example white paint, on glass superstrate configured thin film Si solar cells, this work presents a scheme for producing pigment-based reflectors on complex shape and flexible substrates. Mechanical durability and scalability are demonstrated on a continuous electrophoretic deposition roll-to-roll system which has flexible metal substrate capability of 4 inch wide and 300 feet long. PMID:25836255

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

    International Nuclear Information System (INIS)

    InxGa1?xN, with the tunable direct bandgaps from ultraviolet to near infrared region, offers a promising candidate for the high-efficiency next-generation thin-film photovoltaic applications. Although the adoption of thick InGaN film as the active region is desirable to obtain efficient light absorption and carrier collection compared to InGaN/GaN quantum wells structure, the understanding on the effect from structural design is still unclear due to the poor-quality InGaN films with thickness and difficulty of p-type doping. In this paper, we comprehensively investigate the effects from film epitaxy, doping, and device structural design on the performances of the InGaN-based solar cells. The high-quality InGaN thick film is obtained on AlN/sapphire template, and p-In0.08Ga0.92N is achieved with a high hole concentration of more than 1018?cm?3. The dependence of the photovoltaic performances on different structures, such as active regions and p-type regions is analyzed with respect to the carrier transport mechanism in the dark and under illumination. The strategy of improving the p-i interface by using a super-thin AlN interlayer is provided, which successfully enhances the performance of the solar cells

  1. Diode laser crystallization processes of Si thin-film solar cells on glass

    Directory of Open Access Journals (Sweden)

    Yun Jae Sung

    2014-07-01

    Full Text Available The crystallization of Si thin-film on glass using continuous-wave diode laser is performed. The effect of various processing parameters including laser power density and scanning speed is investigated in respect to microstructure and crystallographic orientation. Optimal laser power as per scanning speed is required in order to completely melt the entire Si film. When scan speed of 15–100 cm/min is used, large linear grains are formed along the laser scan direction. Laser scan speed over 100 cm/min forms relatively smaller grains that are titled away from the scan direction. Two diode model fitting of Suns-Voc results have shown that solar cells crystallized with scan speed over 100 cm/min are limited by grain boundary recombination (n = 2. EBSD micrograph shows that the most dominant misorientation angle is 60°. Also, there were regions containing high density of twin boundaries up to ~1.2 × 10-8/cm2. SiOx capping layer is found to be effective for reducing the required laser power density, as well as changing preferred orientation of the film from ? 110 ? to ? 100 ? in surface normal direction. Cracks are always formed during the crystallization process and found to be reducing solar cell performance significantly.

  2. Studies of compositional dependent CZTS thin film solar cells by pulsed laser deposition technique: An attempt to improve the efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Moholkar, A.V., E-mail: avmoholkar@yahoo.co.in [Electrochemical Materials Laboratory, Department of Physics, Shivaji University, Kolhapur 416004, Maharashtra (India); Shinde, S.S. [Electrochemical Materials Laboratory, Department of Physics, Shivaji University, Kolhapur 416004, Maharashtra (India); Agawane, G.L.; Jo, S.H. [Department of Materials Science and Engineering, Chonnam National University, 300 Yongbong-Dong, Puk-Gu, Gwangju 500 757 (Korea, Republic of); Rajpure, K.Y. [Electrochemical Materials Laboratory, Department of Physics, Shivaji University, Kolhapur 416004, Maharashtra (India); Patil, P.S. [Thin Film Materials Laboratory, Department of Physics, Shivaji University, Kolhapur 416004, Maharashtra (India); Bhosale, C.H. [Electrochemical Materials Laboratory, Department of Physics, Shivaji University, Kolhapur 416004, Maharashtra (India); Kim, J.H., E-mail: jinhyeok@chonnam.ac.kr [Department of Materials Science and Engineering, Chonnam National University, 300 Yongbong-Dong, Puk-Gu, Gwangju 500 757 (Korea, Republic of)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer Synthesis of CZTS thin films by PLD. Black-Right-Pointing-Pointer Effect of stoichiometry, its deviation on the physical properties. Black-Right-Pointing-Pointer Improvement in conversion efficiency using CZTS absorber layer. - Abstract: The performance of CZTS thin films deposited by using pulsed laser deposition technique is investigated as a function of target composition. The chemical composition ratio a = Cu/(Zn + Sn) of the target material has been varied from 0.8 to 1.2 in step of 0.1 by keeping Zn/Sn constant. The effect of the chemical composition in the precursor thin films on the structural, morphological, chemical and optical properties of the CZTS thin films has been investigated. X-ray diffraction and X-ray photoelectron spectroscopy studies showed that the annealed CZTS thin films are of a single kesterite crystal structure without any other secondary phases. The direct band gap energy of the CZTS thin films is found to decrease from 1.72-1.53 eV with increase of 'a'. The estimated band-gap energy from the quantum efficiency measurements is about 1.54 eV. The solar cell fabricated with Glass/Mo/CZTS/CdS/ZnO:Al/Al structure grown using [a = Cu/(Zn + Sn) = 1.1] showed the best conversion efficiency of 4.13% with V{sub oc} = 700 mV, J{sub sc} = 10.01 mA/cm{sup 2} and FF = 0.59.

  3. Natively textured surface hydrogenated gallium-doped zinc oxide transparent conductive thin films with buffer layers for solar cells

    International Nuclear Information System (INIS)

    Natively textured surface hydrogenated gallium-doped zinc oxide (HGZO) thin films have been deposited via magnetron sputtering on glass substrates. These natively textured HGZO thin films exhibit rough pyramid-like textured surface, high optical transmittances in the visible and near infrared region and excellent electrical properties. The experiment results indicate that tungsten-doped indium oxide (In2O3:W, IWO) buffer layers can effectively improve the surface roughness and enhance the light scattering ability of HGZO thin films. The root-mean-square roughness of HGZO, IWO (10 nm)/HGZO and IWO (30 nm)/HGZO thin films are 28, 44 and 47 nm, respectively. The haze values at the wavelength of 550 nm increase from 7.0% of HGZO thin film without buffer layer to 18.37% of IWO (10 nm)/HGZO thin film. The optimized IWO (10 nm)/HGZO exhibits a high optical transmittance of 82.18% in the visible and near infrared region (? ? 400–1100 nm) and excellent electrical properties with a relatively low sheet resistance of 3.6 ?/? and the resistivity of 6.21 × 10?4 ?cm. - Highlights: • Textured hydrogenated gallium-doped zinc oxide (HGZO) films were developed. • Tungsten-doped indium oxide (IWO) buffer layers were applied for the HGZO films. • Light-scattering ability of the HGZO films can be improved through buffer layers. • Low sheet resistance and high haze were obtained for the IWO(10 nm)/HGZO film. • The IWO/HGZO films are promising transparent conductive layers for solar cells

  4. Natively textured surface hydrogenated gallium-doped zinc oxide transparent conductive thin films with buffer layers for solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xin-liang, E-mail: cxlruzhou@163.com; Wang, Fei; Geng, Xin-hua; Huang, Qian; Zhao, Ying; Zhang, Xiao-dan

    2013-09-02

    Natively textured surface hydrogenated gallium-doped zinc oxide (HGZO) thin films have been deposited via magnetron sputtering on glass substrates. These natively textured HGZO thin films exhibit rough pyramid-like textured surface, high optical transmittances in the visible and near infrared region and excellent electrical properties. The experiment results indicate that tungsten-doped indium oxide (In{sub 2}O{sub 3}:W, IWO) buffer layers can effectively improve the surface roughness and enhance the light scattering ability of HGZO thin films. The root-mean-square roughness of HGZO, IWO (10 nm)/HGZO and IWO (30 nm)/HGZO thin films are 28, 44 and 47 nm, respectively. The haze values at the wavelength of 550 nm increase from 7.0% of HGZO thin film without buffer layer to 18.37% of IWO (10 nm)/HGZO thin film. The optimized IWO (10 nm)/HGZO exhibits a high optical transmittance of 82.18% in the visible and near infrared region (? ? 400–1100 nm) and excellent electrical properties with a relatively low sheet resistance of 3.6 ?/? and the resistivity of 6.21 × 10{sup ?4} ?cm. - Highlights: • Textured hydrogenated gallium-doped zinc oxide (HGZO) films were developed. • Tungsten-doped indium oxide (IWO) buffer layers were applied for the HGZO films. • Light-scattering ability of the HGZO films can be improved through buffer layers. • Low sheet resistance and high haze were obtained for the IWO(10 nm)/HGZO film. • The IWO/HGZO films are promising transparent conductive layers for solar cells.

  5. Thin-film solar cells on the basis of semiconducting compounds. Final report; Duennschichtsolarzellen auf Verbindungshalbleiterbasis. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Lewerenz, H.J.; Tributsch, H.; Alonso-Vante, N.; Bogdanoff, P.; Ellmer, K.; Fiechter, S.; Hunger, R.; Jaegermann, W.; Scheer, R.; Tenne, R.

    1997-12-31

    Three studies are reported from the research area `Highly absorbing, semiconducting compounds and transparent contacts`: 1. Preparation and optimization of thin film solar cells on the basis of CuInS{sub 2}; 2. Photoactive thin films and film textures of the metal dichalcogenide compounds for solar cell applications; 3. Transparent, conducting layers for thin film solar cells (CuInS{sub 2}/CdS/ZnO). The very brief report on research into `Photo-electrochemical cells` presents novel electrocatalytic materials, (Ru{sub 1-x}Mo{sub x})SeO{sub z}, which were developed and modified, as well as novel emitter structures for injection-type solar cells with layered compounds WS{sub 2} and MoSo{sub 2}. (orig./MM) [Deutsch] Im Forschungsbereich `Hochabsorbierende Verbindungshalbleiter und transparente Kontakte` wurden drei Untersuchungen durchgefuehrt: 1. Entwicklung und Optimierung von Duennschichtsolarzellen auf der Basis von CuInS{sub 2}; 2. photoaktive Duennschichten und Schichtstrukturen der Schichtgitterchalkogenide fuer Solarzellen; 3. transparent leitende Schichten fuer Duennschichtsolarzellen (CuInS{sub 2}/CdS/ZnO). In den sehr kurz gehaltenen Berichten zum Themenbereich `Photoelektrochemische Zellen` wurden neuartige Materialien fuer die Elektrokatalyse (Ru{sub 1-x}Mo{sub x})SeO{sub z} hergestellt und modifiziert sowie im Themenbereich ``Injektionszellen`` wurden neue Emitterstrukturen fuer Injektionszellen hergestellt (mit Schichtgitterverbindungen WS{sub 2} und MoS{sub 2}). (MM)

  6. Thin-film poly-Si solar cells on glass substrate fabricated at low temperature

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, K.; Yoshimi, M.; Tawada, Y.; Okamoto, Y.; Nakajima, A. [Kaneka Corp., Kobe (Japan). Central Res. Labs.; Igari, S. [Japan Quality Assurance Organization, 4598 Murakushi-cho, Hamamatu-shi, Shizuoka-ken 431-1207 (Japan)

    1999-08-01

    The performances of thin-film poly-Si solar cells with a thickness of less than 5 {mu}m on a glass substrate have been investigated. The cell of glass/back reflector/n-i-p type Si/ITO is well characterized by the structure of naturally surface texture and enhanced absorption with a back reflector (STAR), where the active i-type poly-Si layer was fabricated by plasma chemical vapor deposition (CVD) at low temperature. The cell with a thickness of 2.0 {mu}m demonstrated an intrinsic efficiency of 10.7% (aperture 10.1%), an open-circuit voltage of 0.539 V and a short-current density of 25.8 mA/cm{sup 2} as independently confirmed by Japan Quality Assurance. No light-induced degradation is observed. The optical and transport properties of poly-Si cells are summarized. (orig.) With 13 figs., 3 tabs., 20 refs.

  7. Silicon-Light: a European project aiming at high efficiency thin film silicon solar cells on foil

    OpenAIRE

    Soppe W.; Krc J.; Leitner K.; Haug F.-J.; Duchamp M.; Sanchez Plaza G.; Wang Q.-K.

    2014-01-01

    In the European project Silicon-Light we developed concepts and technologies to increase conversion efficiencies of thin film silicon solar cells on foil. Main focus was put on improved light management, using NIL for creating light scattering textures, improved TCOs using sputtering, and improved silicon absorber material made by PECVD. On foil we achieved initial cell efficiencies of 11% and on rigid substrates stable efficiencies of ...

  8. A rational elemental-directed alcohol-thermal route to CdSe nanostructures for thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yan' ge, E-mail: zygzhang@gmail.com [Institute of Surface Micro and Nano Materials, Key Laboratory of Micro-Nano Materials for Energy Storage and Conversion of Henan Province, Xuchang University, Xuchang 461000 (China); Li, Pinjiang [Institute of Surface Micro and Nano Materials, Key Laboratory of Micro-Nano Materials for Energy Storage and Conversion of Henan Province, Xuchang University, Xuchang 461000 (China); Lau, Woon Ming [Chengdu Green Energy and Green Manufacturing R and D Center, Chengdu 610207 (China); Gao, Yuanhao [Institute of Surface Micro and Nano Materials, Key Laboratory of Micro-Nano Materials for Energy Storage and Conversion of Henan Province, Xuchang University, Xuchang 461000 (China); Zi, Junfeng [College of Chemistry and Chemical Engineering, Xuchang University, Xuchang 461000 (China); Zheng, Zhi [Institute of Surface Micro and Nano Materials, Key Laboratory of Micro-Nano Materials for Energy Storage and Conversion of Henan Province, Xuchang University, Xuchang 461000 (China)

    2014-06-01

    We have reported an alcohol-thermal method to in-situ synthesis of Cadmium Selenide (CdSe) nanocrystals/thin films on Cd/indium-doped tin oxide (ITO) substrates through a direct reaction of Se and Cd. In the synthetic system, ligands and surfactants are not introduced, and concentration of reaction precursors is not high, thus not only it is a very economic and environmental-friendly route, but also the CdSe film without any impurities is obtained. The Cd deposited on ITO substrates by magnetron sputtering acted as dual roles: reactant source and hard template for the final product. The microstructure is analyzed by field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD). Poly(3-hexylthiophene) (P3HT) is deposited on CdSe film to fabricate a hybrid thin film solar cell device with ITO/CdSe/P3HT/Al structure to demonstrate solar light to electrical energy conversion. - Highlights: • CdSe nanocrystals/thin films were fabricated by an easy alcohol-thermal approach. • The method requires no ligands, high concentration of precursors or surfactants. • The photovoltaic device was based on the hybrid thin film of CdSe NCs and P3HT composites.

  9. A rational elemental-directed alcohol-thermal route to CdSe nanostructures for thin film solar cells

    International Nuclear Information System (INIS)

    We have reported an alcohol-thermal method to in-situ synthesis of Cadmium Selenide (CdSe) nanocrystals/thin films on Cd/indium-doped tin oxide (ITO) substrates through a direct reaction of Se and Cd. In the synthetic system, ligands and surfactants are not introduced, and concentration of reaction precursors is not high, thus not only it is a very economic and environmental-friendly route, but also the CdSe film without any impurities is obtained. The Cd deposited on ITO substrates by magnetron sputtering acted as dual roles: reactant source and hard template for the final product. The microstructure is analyzed by field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD). Poly(3-hexylthiophene) (P3HT) is deposited on CdSe film to fabricate a hybrid thin film solar cell device with ITO/CdSe/P3HT/Al structure to demonstrate solar light to electrical energy conversion. - Highlights: • CdSe nanocrystals/thin films were fabricated by an easy alcohol-thermal approach. • The method requires no ligands, high concentration of precursors or surfactants. • The photovoltaic device was based on the hybrid thin film of CdSe NCs and P3HT composites

  10. Influence of optical properties of ZnO thin-films deposited by spray pyrolysis and RF magnetron sputtering on the output performance of silicon solar cell

    International Nuclear Information System (INIS)

    ZnO thin-films were deposited by spray pyrolysis and RF magnetron sputtering techniques. The optical reflection of these thin-films is measured using UV-Vis spectrophotometer. The measured optical reflection data is used in PC-1D simulation software to study the output performance of commercial silicon wafer-based solar cell. As far as optical performance is concerned it could be demonstrated that the sprayed ZnO thin-film under laboratory conditions show equivalent performance compared to sputtered ZnO thin-film. The influence of optical properties of 65 nm thick zinc oxide thin-films deposited by vacuum and non-vacuum techniques on quantum efficiency and IV characteristics of commercial silicon-wafer based solar cell is studied and reported here.

  11. Fabrication of CdS/CdTe-Based Thin Film Solar Cells Using an Electrochemical Technique

    Directory of Open Access Journals (Sweden)

    I. M. Dharmadasa

    2014-06-01

    Full Text Available Thin film solar cells based on cadmium telluride (CdTe are complex devices which have great potential for achieving high conversion efficiencies. Lack of understanding in materials issues and device physics slows down the rapid progress of these devices. This paper combines relevant results from the literature with new results from a research programme based on electro-plated CdS and CdTe. A wide range of analytical techniques was used to investigate the materials and device structures. It has been experimentally found that n-, i- and p-type CdTe can be grown easily by electroplating. These material layers consist of nano- and micro-rod type or columnar type grains, growing normal to the substrate. Stoichiometric materials exhibit the highest crystallinity and resistivity, and layers grown closer to these conditions show n ? p or p ? n conversion upon heat treatment. The general trend of CdCl2 treatment is to gradually change the CdTe material’s n-type electrical property towards i-type or p-type conduction. This work also identifies a rapid structural transition of CdTe layer at 385 ± 5 °C and a slow structural transition at higher temperatures when annealed or grown at high temperature. The second transition occurs after 430 °C and requires more work to understand this gradual transition. This work also identifies the existence of two different solar cell configurations for CdS/CdTe which creates a complex situation. Finally, the paper presents the way forward with next generation CdTe-based solar cells utilising low-cost materials in their columnar nature in graded bandgap structures. These devices could absorb UV, visible and IR radiation from the solar spectrum and combine impact ionisation and impurity photovoltaic (PV effect as well as making use of IR photons from the surroundings when fully optimised.

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

    CERN Document Server

    Wang, DongLin

    2014-01-01

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

  13. Controlling the processable ZnO and polythiophene interface for dye-sensitized thin film organic solar cells

    International Nuclear Information System (INIS)

    Dye-sensitized thin film hybrid solar cells (DS thin film solar cell) were fabricated by one-pot process using solution processable zinc oxide (ZnO) precursor as electron acceptor, ester-functionalized polythiophene copolymer as donor and a squaraine dye. Incorporation of slight amount of ester functionality (6%) in the regioregular poly-3-hexylthiophene (P3HT) main chain leads to enhancement in the photoconversion efficiency of the ester functionalized polymer (P3HT-E) from 0.8% to about 1% (AM1.5, 100 mw/cm2). Photocurrent associated with both of the P3HT-E (400–650 nm) and the squaraine dye (650–750 nm) were observed in incident photon to current efficiency curve of the DS thin film solar cell. This proves that the ZnO/dye/P3HT-E interface could be fabricated by one-pot coating process from ternary mixture based on a ZnO precursor. - Highlights: • Single step and one pot fabrication of dye-sensitized polymer-ZnO hybrid solar cells. • In situ generation of ZnO using its diethyl zinc precursor. • Enhanced photovoltaic performance by introduction of ester functionalized polymers. • Demonstration of far-red photon harvesting by polymer-dye-ZnO ternary blend

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-08-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Slafer, D.; Dalal, V.

    2012-03-01

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

  16. Absorption enhancement in thin film a-Si solar cells with double-sided SiO2 particle layers

    Science.gov (United States)

    Chen, Le; Wang, Qing-Kang; Shen, Xiang-Qian; Chen, Wen; Huang, Kun; Liu, Dai-Ming

    2015-10-01

    Light absorption enhancement is very important for improving the power conversion efficiency of a thin film a-Si solar cell. In this paper, a thin-film a-Si solar cell model with double-sided SiO2 particle layers is designed, and then the underlying mechanism of absorption enhancement is investigated by finite difference time domain (FDTD) simulation; finally the feasible experimental scheme for preparing the SiO2 particle layer is discussed. It is found that the top and bottom SiO2 particle layers play an important role in anti-reflection and light trapping, respectively. The light absorption of the cell with double-sided SiO2 layers greatly increases in a wavelength range of 300 nm-800 nm, and the ultimate efficiency increases more than 22% compared with that of the flat device. The cell model with double-sided SiO2 particle layers reported here can be used in varieties of thin film solar cells to further improve their performances. Project supported by the National High-Tech Research and Development Program of China (Grant No. 2011AA050518), the University Research Program of Guangxi Education Department, China (Grant No. LX2014288), and the Natural Science Foundation of Guangxi Zhuang Autonomous Region, China (Grant No. 2013GXNSBA019014).

  17. NANO-IMPRINT TECHNIQUE FOR BACK REFLECTOR IN HIGH EFFICIENCY N-I-P THIN FILM SILICON SOLAR CELLS

    OpenAIRE

    Söderström, Karin; Escarre Palou, Jordi; Biron, Re?mi; Eminian, Céline; Haug, Franz-Josef; Ballif, Christophe; Garcia, Cubero; Jesus, Oscar

    2010-01-01

    In this contribution, the replication of nano-textures enhancing the short circuit current of thin film silicon solar cells onto low cost substrates (glass or PolyEthylene Naphtalate (PEN)) is studied. Optical and morphological analysis is performed to asses the quality of these replicas. Single and tandem a-Si:H solar cells are deposited on top of the master and replica structures to verify their suitability to be used as substrates for solar cells in substrate (n-i-p) configuration. We find...

  18. Evaluation of the efficiency potential of intermediate band solar cells based on thin-film chalcopyrite materials

    OpenAIRE

    Martí Vega, Antonio; Fuertes Marrón, David; Luque López, Antonio

    2008-01-01

    This paper discusses the potential of the intermediate band solar cell _IBSC_ concept to improve the efficiency of thin-film chalcopyrite solar cells. The results show that solar cells based on CuGaS2, with a radiative limiting efficiency of 46.7%, exhibit the highest potential. A simple method for the identification of transition elements that when incorporated in CuGaS2 could possibly introduce an intermediate band is also described. The IBSC concept is also applied under the assumptions th...

  19. Liquid-phase pulsed laser ablation and electrophoretic deposition for chalcopyrite thin-film solar cell application.

    Science.gov (United States)

    Guo, Wei; Liu, Bing

    2012-12-01

    We report ligand-free synthesis of colloidal metallic nanoparticles using liquid-phase pulsed laser ablation, and electrophoretic deposition of the nanoparticles for fabrication of Cu(In,Ga)Se(2) (CIGS) thin film solar cells. First, colloidal metallic nanoparticles of Cu-In and Cu-Ga alloys are produced by pulsed laser ablation in common organic solvents without using stabilizing ligands. The nanoparticles are examined for phase, composition, and electrical surface charging and charge modulation mechanisms. Metallic precursor thin films with high purity and precise composition are produced by electrophoretic deposition of the colloids without transferring to another solvent and without using binders. Finally, we demonstrate fabrication of CIGS solar cells on Mo sheet substrates with an (active area) energy conversion efficiency up to 7.37%. PMID:23206317

  20. Broadband light trapping in thin film solar cells with self-organized plasmonic nano-colloids

    Science.gov (United States)

    Mendes, Manuel J.; Morawiec, Seweryn; Mateus, Tiago; Lyubchyk, Andriy; Águas, Hugo; Ferreira, Isabel; Fortunato, Elvira; Martins, Rodrigo; Priolo, Francesco; Crupi, Isodiana

    2015-03-01

    The intense light scattered from metal nanoparticles sustaining surface plasmons makes them attractive for light trapping in photovoltaic applications. However, a strong resonant response from nanoparticle ensembles can only be obtained if the particles have monodisperse physical properties. Presently, the chemical synthesis of colloidal nanoparticles is the method that produces the highest monodispersion in geometry and material quality, with the added benefits of being low-temperature, low-cost, easily scalable and of allowing control of the surface coverage of the deposited particles. In this paper, novel plasmonic back-reflector structures were developed using spherical gold colloids with appropriate dimensions for pronounced far-field scattering. The plasmonic back reflectors are incorporated in the rear contact of thin film n-i-p nanocrystalline silicon solar cells to boost their photocurrent generation via optical path length enhancement inside the silicon layer. The quantum efficiency spectra of the devices revealed a remarkable broadband enhancement, resulting from both light scattering from the metal nanoparticles and improved light incoupling caused by the hemispherical corrugations at the cells’ front surface formed from the deposition of material over the spherically shaped colloids.

  1. Simulation approach for studying the performances of original superstrate CIGS thin films solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Bouchama, I., E-mail: bouchama_idris@yahoo.fr [Laboratoire Procedes Materiaux et Energie solaire PROMES-CNRS, Rambla de la Thermodynamique, Technosud, 66100 Perpignan (France); Laboratoire L.I.S., Universite Ferhat Abbas de Setif (Algeria); Djessas, K. [Laboratoire Procedes Materiaux et Energie solaire PROMES-CNRS, Rambla de la Thermodynamique, Technosud, 66100 Perpignan (France); Djahli, F. [Laboratoire L.I.S., Universite Ferhat Abbas de Setif (Algeria); Bouloufa, A. [Laboratoires C.C.N.S. et E. M., Universite Ferhat Abbas de Setif (Algeria)

    2011-08-31

    In this work, we report on the performances of superstrate Cu(In,Ga)Se{sub 2} (CIGS) thin film solar cells with an alternative SLG/SnO{sub 2}:F/CIGS/In{sub 2}Se{sub 3}/Zn structure using AMPS-1D (Analysis of Microelectronic and Photonic structures) device simulator. An inverted surface layer, n-type CIGS layer, is inserted between the In{sub 2}Se{sub 3} buffer and CIGS absorber layers and the SnO{sub 2}:F layer is just a transparent conducting oxide (TCO). The simulation has been carried out by lighting through SnO{sub 2}:F. The obtained results show that the existence of so-called 'ordered defect compound' (ODC) layer in such a structure is the critical factor responsible for the optimization of the performances. Photovoltaic parameters were determined using the current density-voltage (J-V) curve. An optimal absorber and ODC layer thickness has been estimated, that improve significantly the devices efficiency exceeding 15% AM1.5 G. The variation of carrier density in In{sub 2}Se{sub 3} layer has an influence on the superstrate CIGS cells performances. Moreover, the quantum efficiency (Q.E.) characteristics display a maximum value of about 80% in the visible range.

  2. Simulation approach for studying the performances of original superstrate CIGS thin films solar cells

    International Nuclear Information System (INIS)

    In this work, we report on the performances of superstrate Cu(In,Ga)Se2 (CIGS) thin film solar cells with an alternative SLG/SnO2:F/CIGS/In2Se3/Zn structure using AMPS-1D (Analysis of Microelectronic and Photonic structures) device simulator. An inverted surface layer, n-type CIGS layer, is inserted between the In2Se3 buffer and CIGS absorber layers and the SnO2:F layer is just a transparent conducting oxide (TCO). The simulation has been carried out by lighting through SnO2:F. The obtained results show that the existence of so-called 'ordered defect compound' (ODC) layer in such a structure is the critical factor responsible for the optimization of the performances. Photovoltaic parameters were determined using the current density-voltage (J-V) curve. An optimal absorber and ODC layer thickness has been estimated, that improve significantly the devices efficiency exceeding 15% AM1.5 G. The variation of carrier density in In2Se3 layer has an influence on the superstrate CIGS cells performances. Moreover, the quantum efficiency (Q.E.) characteristics display a maximum value of about 80% in the visible range.

  3. Ion beam treatment of functional layers in thin-film silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wendi

    2013-10-01

    In silicon thin-film solar cells, transparent conductive layers have to fulfill the following requirements: high conductivity as effective contact, high transparency to transmit the light into the cell, and a textured surface which provides light scattering. Magnetron sputtered and wet-chemically textured aluminum doped zinc oxide (ZnO:Al) films are widely used as the transparent conductor. The technological goal of this dissertation is to develop an alternative to the wet etching process for light trapping in the thin silicon absorber layers through modification of the glass/ZnO:Al or ZnO:Al/Si interfaces by ion beam treatment. The study focuses on the textured growth of ZnO:Al films on ion beam pretreated glass substrates, and the preparation and application of textured glass for light trapping. The technological aspects such as the etch rates of the glass substrate and ZnO:Al films with different ion beam configurations were studied. The experimental etch rates are compared with simulated and theoretically predicted values. With regard to the ion beam treatment of glass substrate, the influence of the ion pretreated glass on the growth of ZnO:Al films was investigated. The ZnO:Al films grown on ion beam pretreated glass substrates exhibit self-textured morphology with surface roughness of 40 nm while remaining highly conductive. Silicon thin-film solar cells prepared on the as-grown rough ZnO:Al films show that this front contact can provide excellent light trapping effect. The highest initial efficiencies for amorphous single junction solar cells on as-grown rough ZnO:Al films was 9.4%. The as-grown rough morphology was attributed to large conical ZnO:Al grains initiated from the ion pretreated glass surface. It was found that the roughness of the as-grown rough ZnO:Al film is proportional to the number of O dangling bonds created by ion beam treatment on the glass substrate. A growth model was proposed to explain the growth mechanism of ZnO:Al films on Zn- and O-polar ZnO single crystals, as well as on untreated and ion beam treated glass substrates. With regard to the ion beam treatment of ZnO:Al films, the influence of the ion treatment on the surface morphology, HCl etching, silicon growth, and additional ZnO:Al growth was investigated. Ion beam etching has a smoothening effect on the textured ZnO:Al films. Using sputtered and wet chemically etched ZnO:Al as ion beam etching mask, textured glass with features similar to the ZnO:Al films were obtained. Textured glass with a wide range of morphologies was prepared by varying the etching mask and the ion beam treatment conditions. Finally, as-grown textured ZnO:Al films prepared on ion beam treated textured glass, which exhibit 'double textured' features, were produced and applied in solar cells. The ion beam treatment enabled the preparation of light scattering surfaces by textured glass and as-grown rough ZnO:Al films without the need of wet etching between TCO preparation and absorber deposition. Further, new 'double textured' surface structures could be created by the combination of both techniques. Solar cells with efficiency of 11.9% proved the applicability as-grown textured ZnO:Al for light trapping. The growth studies provided deeper insights and a new understanding of ZnO structure formation and will govern optimization of ZnO:Al film properties.

  4. Microscopic properties of grain boundaries in Cu(In,Ga)Se2 and CuInS2 thin-film solar cells studied by transmission electron microscopy

    OpenAIRE

    Schmidt, Sebastian Simon

    2011-01-01

    Polycrystalline Cu(In,Ga)Se2 and Cu(In,Ga)S2 thin films are employed as absorber layers in highly efficient thin-film solar cells. The impact of grain boundaries on the electronic properties of these thin films and consequently on the conversion efficiency of the corresponding solar cells is not sufficiently understood. In the present work, methods in transmission electron microscopy were employed in order to study the microscopic properties of grain boundaries in Cu(In,Ga)(Se,S)2 layers with...

  5. Micromorph thin-film silicon solar cells with transparent high-mobility hydrogenated indium oxide front electrodes

    OpenAIRE

    Battaglia, Corsin; Erni, Lukas; Boccard, Mathieu; Barraud, Loris; Escarre?, Jordi; Söderström, Karin; Bugnon, Grégory; Billet, Adrian; Ding, Laura; Despeisse, Matthieu; Haug, Franz-Josef; De Wolf, Stefaan; Ballif, Christophe

    2011-01-01

    We investigate the performance of hydrogenated indium oxide as a transparent front electrode for micromorph thin-film silicon solar cells on glass. Light trapping is achieved by replicating the morphology of state-of-the-art zinc oxide electrodes, known for their outstanding light trapping properties, via ultraviolet nanoimprint lithography. As a result of the high electron mobility and excellent near-infrared transparency of hydrogenated indium oxide, the short-circuit current density of the...

  6. Reactive sputtering and composition measurements of precursors for Cu2ZnSnS4 thin film solar cells

    OpenAIRE

    Ericson, Tove

    2013-01-01

    Cu2ZnSnS4 (CZTS) is a thin film solar cell material that only contains abundant elements and for which promising conversion efficiencies of 9.2 % have been shown. In this thesis composition measurements and reactive sputtering of precursors for CZTS films have been studied. These precursors can be annealed to create high quality CZTS films. Accurate control and measurement of composition are important for the synthesis process. The composition of a reference sample was determined using Ruther...

  7. Silicon-Light: a European FP7 Project Aiming at High Efficiency Thin Film Silicon Solar Cells on Foil

    DEFF Research Database (Denmark)

    Soppe, W.; Haug, F.-J.; Couty, P.; Duchamp, Martial; Schipper, W.; Krc, J.; Sanchez, G.; Leitner, K.; Wang, Qin; Ossenbrink, H.; Jager-Waldau, A.; Helm, P.

    2011-01-01

    Silicon-Light is a European FP7 project, which started January 1st, 2010 and aims at development of low cost, high-efficiency thin film silicon solar cells on foil. Three main routes are explored to achieve these goals: a) advanced light trapping by implementing nanotexturization through UV Nano Imprinting Lithography (UV-NIL); b) growth of crack-free silicon absorber layers on highly textured substrates; c) development of new TCOs which should combine the best properties of presently available ...

  8. Novel laser structuring of CIGSE thin film solar cells; Neuartige Laserstrukturierung von CIGSE-Duennschicht-Solarzellen

    Energy Technology Data Exchange (ETDEWEB)

    Stegemann, B.; Schultz, C.; Schuele, M.; Richter, M.; Quaschning, V.; Fink, F. [University of Applied Sciences (HTW) Berlin (Germany); Pahl, H.U.; Endert, H. [Newport Spectra-Physics GmbH, Stahnsdorf (Germany); Bonse, J. [Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin (Germany); Rau, B.; Schlatmann, R. [PVcomB - Competence Centre Thin-Film- and Nanotechnology for Photovoltaics Berlin, Berlin (Germany)

    2011-07-01

    A major advantage of thin film photovoltaics over wafer-based photovoltaics is the monolithic series connection. Manufacturing of chalcopyrite (CICSe) thin film solar modules involves typically one laser structuring step (P1) and two mechanical structuring steps (P2 and P3) for serial interconnection. In our approach, complete laser structuring is successfully demonstrated simply by application of short nanosecond pulses (<10 ns) with a single, visible wavelength of 532 nm. The P1 and the P3 trenches are scribed by induced direct ablation. For the P2 scribe, the thermal input of the ns laser pulses is used to transform the CIGSe absorber layer locally into a highly conductive compound to provide proper electrical interconnection between the front and back contact. (orig.)

  9. Aqueous Solution-Phase Selenized CuIn(S,Se)2 Thin Film Solar Cells Annealed under Inert Atmosphere.

    Science.gov (United States)

    Oh, Yunjung; Yang, Wooseok; Kim, Jimin; Woo, Kyoohee; Moon, Jooho

    2015-10-14

    A nonvacuum solution-based approach can potentially be used to realize low cost, roll-to-roll fabrication of chalcopyrite CuIn(S,Se)2 (CISSe) thin film solar cells. However, most solution-based fabrication methods involve highly toxic solvents and inevitably require sulfurization and/or postselenization with hazardous H2S/H2Se gases. Herein, we introduce novel aqueous-based Cu-In-S and Se inks that contain an amine additive for producing a high-quality absorber layer. CISSe films were fabricated by simple deposition of Cu-In-S ink and Se ink followed by annealing under an inert atmosphere. Compositional and phase analyses confirmed that our simple aqueous ink-based method facilitated in-site selenization of the CIS layer. In addition, we investigated the molecular structures of our aqueous inks to determine how crystalline chalcopyrite absorber layers developed without sulfurization and/or postselenization. CISSe thin film solar cells annealed at 550 °C exhibited an efficiency of 4.55% under AM 1.5 illumination. The low-cost, nonvacuum method to deposit chalcopyrite absorber layers described here allows for safe and simple processing of thin film solar cells. PMID:26394216

  10. Characterization of Thin Films for Polymer Solar Cells : Stability and Response to Concentrated Light

    DEFF Research Database (Denmark)

    Tromholt, Thomas

    2012-01-01

    The field of polymer solar cells has undergone an extensive development in recent years after the invention of semiconducting polymers in 1991. Efficiencies have gradually increased to above 10 %, and high throughput processing methods such as roll-to-roll coating allow for production of thousands of solar cells with low embedded time, material, and energy consumption as compared to silicon solar cells. Consequently, different demonstration products of small mobile gadgets based on polymer solar cells have been produced, which are fully competitive with conventional energy technologies, illustrating the maturity of the technology. However, a limiting factor in terms of full commercialization is the stability of polymer solar cells. While is has been estimated that 10 years lifetime is needed, existing technologies only provide stabilities up to 1 year. Degradation of polymer solar cell is a multi facetted process where oxygen and water diffusion from the atmosphere, morphology evolution, and photo-bleaching of the polymer are some of the dominant processes. Encapsulation by foils consisting of multi-layer polymer stacks is a conventional way to reduce the diffusion into the solar cell, by which the life time of the cell is highly increased. An alternative approach is to increase the photo stability of the cell components, and especially the light absorbing conjugated polymer has been subject to extensive attention. The photo stability of conjugated polymers varies by orders of magnitude from type to type depending on the chemical structure of the material and consequently, the lifetime is highly influenced by the polymer stability. Photochemical degradation of polymers, i.e. degradation of thin films of polymer in the ambient under light exposure, is a technique normally applied to evaluate polymer stabilities. Hereby, an extensive list of stabilities of different materials has been established providing an understanding of the stability of the individual building blocks of polymer. While being a highly practical tool, no rigorous reports on the photochemical degradation as a technique exist where the technique is validated and different pit-falls identified. Consequently, a rigorous study on the validation and maturing of this technique was performed during this PhD work (Chapter 2). Furthermore, as research gradually increases the lifetime of polymers to months or years, stability evaluations at standard degradation conditions become impractical. Accelerated degradation has been performed with heat and different gases by which the timeframe of stability evaluations have been reduced by up to a factor of 20. However, light, which appears at the most intuitive acceleration condition to conjugated polymers, has until this PhD work not been applied as an acceleration condition to polymer degradation. Light can be concentrated up to thousand of solar intensities by optical components, which has the potential to significantly accelerate polymer degradation. Concentration of light was one of the main topics during this PhD, where the construction and development of light concentrators, both by sun light as well as artificial light, was given extensive attention. This resulted in three different light concentrators, a lens based solar concentrator, a mirror based solar concentrator, and an artificial light concentrator for indoor use (Chapter 3). With these concentration setups, acceleration factors of up to 1200 were obtained for degradation of typical conjugated polymers thus significantly reducing the timeframe of stability evaluations. The potential of this approach is that stability evaluation can become a routine characterization techniquefor novel conjugated polymers, when these are applied to polymer solar cells and their efficiencies are reported. By making the polymer stability practically accessible, development of polymer stability can become significantly more transparent and focused (Chapter 4). A direct alternative application of concentrated light is the application to polymer solar cells. Stabilities of polyme

  11. FTIR spectroscopy of silicon carbide thin films prepared by PECVD technology for solar cell application

    Science.gov (United States)

    Kleinová, Angela; Huran, Jozef; Sasinková, Vlasta; Perný, Milan; Å ály, Vladimír.; Packa, Juraj

    2015-09-01

    The plasma CVD reactor with parallel plate electrodes was used for plasma enhanced chemical vapor deposition (PECVD) of two type's silicon carbide thin films on Si substrates. The concentration of elements in the films was determined by RBS and ERD analytical method simultaneously. The chemical compositions of the samples were analyzed by FTIR method. RBS and ERD results showed that the films contain silicon, carbon, hydrogen and small amount of oxygen. FTIR results confirmed the presence of Si-C, Si-H, C-H, and Si-O bonds. From the FTIR spectra the main following vibration frequencies were determined: the band from 2800 to 3000 cm-1 is attributed to stretching vibration of the CHn group in both the sp2 (2880 cm-1) and sp3 (2920 cm-1) configurations. The band at 2100 cm-1 is due to SiHm stretching vibrations. The band at 780 cm-1 can be assigned to Si-C stretching vibration. Main features of FTIR spectra were Gaussian fitted and detailed analyses of chemical bonding in SiC films were performed. Differences between two types of SiC films were discussed with the aim to using these films in the heterojunction solar cell technology.

  12. Optical and electronic contributions in double-heterojunction organic thin-film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Haensel, H.; Zettl, H. [Physikalische Chemie II, Universitaet Bayreuth, D-95440 Bayreuth (Germany); Bayreuther Zentrum fuer Kolloid und Grenzflaechenforschung (BZKG), D-95440 Bayreuth (Germany); Krausch, G. [Bayreuther Zentrum fuer Kolloid und Grenzflaechenforschung (BZKG), D-95440 Bayreuth (Germany); Kisselev, R.; Thelakkat, M.; Schmidt, H.W. [Makromolekulare Chemie I and Bayreuther Zentrum fuer Kolloid und Grenzflaechenforschung (BZKG), Universitaet Bayreuth, D-95440 Bayreuth (Germany)

    2003-12-17

    Combinatorial studies of organic thin-film photovoltaic cells can identify the separate optical and electronic contributions to the photocurrent. A second charge-transfer zone is proposed to explain the observed augmentation of the short-circuit current induced by an additional TiO{sub 2} layer. The ratio of the exciton diffusion lengths in copper phthalocyanine (CuPc) and a perylene dye (DMPTI) is estimated to be {approx}8:5. (Abstract Copyright [2003], Wiley Periodicals, Inc.)

  13. High molar extinction coefficient heteroleptic ruthenium complexes for thin film dye-sensitized solar cells.

    Science.gov (United States)

    Kuang, Daibin; Ito, Seigo; Wenger, Bernard; Klein, Cedric; Moser, Jacques-E; Humphry-Baker, Robin; Zakeeruddin, Shaik M; Grätzel, Michael

    2006-03-29

    Two novel heteroleptic sensitizers, Ru((4,4-dicarboxylic acid-2,2'-bipyridine)(4,4'-bis(p-hexyloxystyryl)-2,2-bipyridine)(NCS)2 and Ru((4,4-dicarboxylic acid-2,2'-bipyridine)(4,4'-bis(p-methoxystyryl)-2,2'-bipyridine) (NCS)2, coded as K-19 and K-73, respectively, have been synthesized and characterized by 1H NMR, FTIR, UV-vis absorption, and emission spectroscopy and excited-state lifetime and spectroelectrochemical measurements. The introduction of the alkoxystyryl group extends the conjugation of the bipyridine donor ligand increasing markedly their molar extinction coefficient and solar light harvesting capacity. The dynamics of photoinduced charge separation following electronic excitation of the K-19 dye was scrutinized by time-resolved laser spectroscopy. The electron transfer from K-19 to the conduction band of TiO2 is completed within 20 fs while charge recombination has a half-life time of 800 s. The high extinction coefficients of these sensitizers enable realization of a new generation of a thin film dye sensitized solar cell (DSC) yielding high conversion efficiency at full sunlight even with viscous electrolytes based on ionic liquids or nonvolatile solvents. An unprecedented yield of over 9% was obtained under standard reporting conditions (simulated global air mass 1.5 sunlight at 1000 W/m2 intensity) when the K-73 sensitizer was combined with a nonvolatile "robust" electrolyte. The K-19 dye gave a conversion yield of 7.1% when used in conjunction with the binary ionic liquid electrolyte. These devices exhibit excellent stability under light soaking at 60 degrees C. The effect of the mesoscopic TiO2 film thickness on photovoltaic performance has been analyzed by electrochemical impedance spectroscopy (EIS). PMID:16551124

  14. Co-electroplated Kesterite Bifacial Thin-Film Solar Cells: A Study of Sulfurization Temperature.

    Science.gov (United States)

    Ge, Jie; Chu, Junhao; Yan, Yanfa; Jiang, Jinchun; Yang, Pingxiong

    2015-05-20

    Earth-abundant material, kesterite Cu2ZnSnS4 (CZTS), demonstrates the tremendous potential to serve as the absorber layer for the bifacial thin-film solar cell. The exploration of appropriate sulfurization conditions including annealing temperature is significant to gain insight into the growth mechanism based on the substrates using transparent conductive oxides (TCO) and improve device performance. The kesterite solar absorbers were fabricated on ITO substrates by sulfurizing co-electroplated Cu-Zn-Sn-S precursors in argon diluted H2S atmosphere at different temperatures (475-550 °C) for 30 min. Experimental proof, including cross-section scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, UV-vis-NIR transmission spectrum, and Raman and far-infrared spectroscopy, is presented for the crystallization of CZTS on an ITO substrate and the interfacial reaction between the ITO back contact and CZTS absorber. The complete conversion of precursor into CZTS requires at least 500 °C sulfurization temperature. The aggressive interfacial reaction leading to the out-diffusion of In into CZTS to a considerable extent, formation of tin sulfides, and electrically conductive degradation of ITO back contact occurs at the sulfurization temperatures higher than 500 °C. The bifacial devices obtained by 520 °C sulfurization exhibit the best conversion efficiencies and open circuit voltages. However, the presence of non-ohmic back contact (secondary diode), the short minority lifetime, and the high interfacial recombination rates negatively limit the open circuit voltage, fill factor, and efficiency, evidenced by illumination/temperature-dependent J-V, frequency-dependent capacitance-voltage (C-V-f), time-resolved PL (TRPL), and bias-dependent external quantum efficiency (EQE) measurements. PMID:25871647

  15. Experimental study of Cu2ZnSn(Se,S)4 thin films for solar cell applications

    OpenAIRE

    Engman, Jessica

    2011-01-01

    Cu2ZnSn(Se,S)4 (CZT(Se,S)) has recently been shown to be a promising material to use in thin film solar cells. It has a band gap of between 1eV (CZTSe) and 1.5eV (CZTS). CZT(Se,S) solar cells have reached 10% efficiency.   The aim of this project was to find an effective way to selenise metallic Cu, Zn, Sn films in order to produce Cu2ZnSnSe4 (CZTSe) films, without destroying the metallic molybdenum (Mo) back contact. Another aim was to make films containing both Se and S and to study the pos...

  16. Simulation and characterization of performance of thin-film silicon solar cells with subwavelength nanoporous emitter profiles

    Science.gov (United States)

    Ho, Wen-Jeng; Chang, Chia-Min; Tsai, Po-Hung

    2015-11-01

    Surface properties of a thin-film p-on-n silicon solar cell with a subwavelength nanoporous structure fabricated on an emitter layer by using metal-assisted chemical etching (MACE) were investigated through an experiment and simulation. After 10-s MACE processing, the conversion efficiency increased by 43.09% (from 5.64% to 8.07%) was obtained, compared with a reference solar cell without MACE. The simulation result indicated that the surface recombination velocity was an exponential function of the etching time from 0 to 30 s, and showed close agreement with the experimental data.

  17. Characterization of Optic Properties ZnO:Al Thin Film on Glass Substrate for Solar Cell Window

    International Nuclear Information System (INIS)

    It has been characterized a ZnO:Al thin film growth using sputtering technique for solar cell window. The aims of this research is to get a ZnO:Al thin film that can be used as a TCO (Transparent Conducting Oxide) on amorphous silicon solar cell. To get an optimum properties, deposition process has been done for various parameters, such as composition/concentration of Al, substrate temperature, gas pressure and deposition time. Based on experiments result, it is found that the optimum result was achieved at temperature 450 oC, gas pressure 6 x 10 -2 torr and time 1.5 hours. From optical properties (transmittance) measurements using UV-vis, it was found that the optimum results was achieved at temperature 450 oC. At this conditions, wave length (500 - 800) nm, the transmittance was (50 - 82) %, at pressure 6 x 10 -2 torr the transmittance was (50 - 80) % and at deposition time 1.5 hours was (49 - 81) %. For ZnO thin film, was at wave length (500 - 800) nm, the transmittance was (78 - 80) %. From micro structure analysis using SEM, it was found that the thickness layer of ZnO was 1.5 ?m and 1.3 ?m for ZnO: Al. While from surface morphology it was found that for ZnO thin layer the grains was distributed homogeneously, while for ZnO: Al the grains was distributed unhomogeneously. (author)

  18. Efficiency potential of thin film polycrystalline silicon solar cells by silane-gas-free process using aluminum-induced-crystallization

    Energy Technology Data Exchange (ETDEWEB)

    Ito, TadashiTadashi; Fukushima, Hideoki [TOYOTA Central Research and Development Labs., Aichi (Japan); Yamaguchi, Masafumi [Toyota Technological Inst., Nagoya (Japan)

    2004-06-01

    Analyzing the performance of thin film polycrystalline silicon solar cells fabricated by silane-gas-free process including the aluminum-induced-crystallization technique by using the device simulation program 'PC1D', we have estimated the efficiency of them. In addition, we have discussed the issues to make the silane-gas-free process practical. In the cell fabrication by silane-gas-free process, segregation of impurity atoms at the grain boundaries of the Si film is one of the serious problems. By suppressing the impurity inclusion and optimizing the cell parameters, the simulated efficiency is to be about 13% in single-junction cells. (Author)

  19. Impacts of proton irradiation on optical and electrical properties of Cu(In,Ga)Se2 thin films and solar cells

    International Nuclear Information System (INIS)

    The optical and electrical properties of proton irradiated Cu(In,Ga)Se2 (CIGS) solar cells and the thin films that compose the CIGS solar cell structure were investigated. The transmittance and resistivity of transparent conducting oxide window layers remained constant for a fluence of up to 3 × 1015 cm-2. For CIGS thin films, the number of non-radiative recombination center increases under proton irradiation. In CIGS solar cells, decreasing JSC reflected the degradation of the depletion layer of the CdS/CIGS interface. These results constitute the first step in clarifying the degradation mechanism of CIGS solar cells. (author)

  20. Combined model of non-conformal layer growth for accurate optical simulation of thin-film silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Sever, M.; Lipovsek, B.; Krc, J.; Campa, A.; Topic, M. [University of Ljubljana, Faculty of Electrical Engineering Trzaska cesta 25, Ljubljana 1000 (Slovenia); Sanchez Plaza, G. [Technical University of Valencia, Valencia Nanophotonics Technology Center (NTC) Valencia 46022 (Spain); Haug, F.J. [Ecole Polytechnique Federale de Lausanne EPFL, Institute of Microengineering IMT, Photovoltaics and Thin-Film Electronics Laboratory, Neuchatel 2000 (Switzerland); Duchamp, M. [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons Institute for Microstructure Research, Research Centre Juelich, Juelich D-52425 (Germany); Soppe, W. [ECN-Solliance, High Tech Campus 5, Eindhoven 5656 AE (Netherlands)

    2013-12-15

    In thin-film silicon solar cells textured interfaces are introduced, leading to improved antireflection and light trapping capabilities of the devices. Thin-layers are deposited on surface-textured substrates or superstrates and the texture is translated to internal interfaces. For accurate optical modelling of the thin-film silicon solar cells it is important to define and include the morphology of textured interfaces as realistic as possible. In this paper we present a model of thin-layer growth on textured surfaces which combines two growth principles: conformal and isotropic one. With the model we can predict the morphology of subsequent internal interfaces in thin-film silicon solar cells based on the known morphology of the substrate or superstrate. Calibration of the model for different materials grown under certain conditions is done on various cross-sectional scanning electron microscopy images of realistic devices. Advantages over existing growth modelling approaches are demonstrated - one of them is the ability of the model to predict and omit the textures with high possibility of defective regions formation inside the Si absorber layers. The developed model of layer growth is used in rigorous 3-D optical simulations employing the COMSOL simulator. A sinusoidal texture of the substrate is optimised for the case of a micromorph silicon solar cell. More than a 50 % increase in short-circuit current density of the bottom cell with respect to the flat case is predicted, considering the defect-free absorber layers. The developed approach enables accurate prediction and powerful design of current-matched top and bottom cell.

  1. Large CZTS Nanoparticles Synthesized by Hot-Injection for Thin Film Solar Cells.

    DEFF Research Database (Denmark)

    Engberg, Sara Lena Josefin; Lam, Yeng Ming

    The kesterite material, Cu2ZnSn(SxSe1-x)4 (CZTS), shows great promise as the absorber layer for future thin film solar cells. Solution processing allows for comparatively fast and inexpensive fabrication, and holds the record efficiency in the kesterite family. However, for nanoparticle (NP) solution processing to be a feasible fabrication route, the amount of carbon in the film has to be limited. In our work, we try to limit the organic material in the film by synthesizing larger NPs. Larger particles can be obtained by longer reaction durations, slower reaction rates of the precursors, or slower injection rates of the sulfur/selenium precursors. In our group, we have synthesized NPs larger than 200 nm by controlling the monomer concentration during growth. Transmission electron microscopy (TEM) allows us to image the NPs and determine their individual composition. Size-selective methods can be carried out in order to isolate the desired particle sizes, and films will be deposited through wet-chemical means.Mixing large NPs with small NPs can also improve the film-quality as a result of densification at the optimal packing density. The films are characterized by scanning electron microscopy (SEM) as well as other surface characterization techniques. Our first photovoltaic device consisting of soda lime glass/Mo/CZTS/CdS/ZnO has been built from doctor blading of approx. 20 nm Cu2ZnSnS4 NPs in octanethiol, and annealed in Se-atmosphere. It had an efficiency of 1.4%.

  2. Doped and multi-compound ZnO-based transparent conducting oxides for silicon thin film solar cells

    OpenAIRE

    Carreras Seguí, Paz

    2013-01-01

    [eng] The objective of the present work is to provide a better understanding of magnetron sputtered transparent conducting oxides based on ZnO in order to use them as electrodes in thin film silicon solar cells at the Grup d'Energia Solar of the Universitat de Barcelona. This thesis presents the properties of magnetron sputtered aluminium and gallium doped ZnO as well as the properties of multi-compound materials deposited by the co-sputtering of zinc oxide and indium tin oxide. The applicati...

  3. Electronic grain boundary properties in polycrystalline Cu(In,Ga)Se{sub 2} semiconductors for thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Baier, Robert

    2012-06-25

    Solar cells based on polycrystalline Cu(In,Ga)Se{sub 2} (CIGSe) thin film absorbers reach the highest energy conversion efficiency among all thin film solar cells. The record efficiency is at least partly attributed to benign electronic properties of grain boundaries (GBs) in the CIGSe layers. However, despite a high amount of research on this phenomenon the underlying physics is not sufficiently understood. This thesis presents an elaborate study on the electronic properties of GBs in CIGSe thin films. Kelvin probe force microscopy (KPFM) was employed to investigate the electronic properties of GBs in dependence of the Ga-content. Five CIGSe thin lms with various Ga-contents were grown by means of similar three stage co-evaporation processes. Both as grown as well as chemically treated (KCN etched) thin films were analyzed. The chemical treatment was employed to remove surface oxides. No difference in electronic GB properties was found with or without the chemical treatment. Therefore, we conclude that a moderate surface oxidation does not alter the electronic properties of GBs. In general, one can observe significant variations of electronic potential barriers at GBs. Under consideration of the averaging effect of the work function signal of nanoscale potential distributions in KPFM measurements which was quantified in the course of this thesis both positive and negative potential barriers in a range between ?-350 mV and ?+450 mV were detected. Additionally, variations in the defect densities at GBs between ?3.1 x 10{sup 11} cm{sup -2} and ?2.1 x 10{sup 12} cm{sup -2} were found. However, no correlation between the electronic properties of GBs and the Ga-content of CIGSe thin films was discovered. Consequently, one cannot explain the drop in device efficiency observed for CIGSe thin film solar cells with a high Ga-content by a change of the electronic properties of GBs. Combined KPFM and electron backscatter diffraction measurements were employed for the first time on CIGSe thin films to gather complementary information about both the structural and electronic properties of individual GBs. With the help of this information it was possible to investigate the interrelationship between the symmetry and the electronic potential barrier of GBs. We could reveal that highly symmetric ?3 GBs have a lower probability to possess a charged potential barrier than lower symmetric non-?3 GBs. The assumption of a general symmetry-dependence of the electronic properties of GBs in CIGSe, i.e. a correlation between the particular symmetry of a GB and its potential barrier that is also valid for GBs with symmetries lower than ?3, could help to explain the large variations of potential barriers observed at GBs in polycrystalline CIGSe thin films.

  4. Solution-Processed Cu2ZnSn(S,Se) 4 Thin-Film Solar Cells Using Elemental Cu, Zn, Sn, S, and Se Powders as Source.

    Science.gov (United States)

    Guo, Jing; Pei, Yingli; Zhou, Zhengji; Zhou, Wenhui; Kou, Dongxing; Wu, Sixin

    2015-12-01

    Solution-processed approach for the deposition of Cu2ZnSn (S,Se)4 (CZTSSe) absorbing layer offers a route for fabricating thin film solar cell that is appealing because of simplified and low-cost manufacturing, large-area coverage, and better compatibility with flexible substrates. In this work, we present a simple solution-based approach for simultaneously dissolving the low-cost elemental Cu, Zn, Sn, S, and Se powder, forming a homogeneous CZTSSe precursor solution in a short time. Dense and compact kesterite CZTSSe thin film with high crystallinity and uniform composition was obtained by selenizing the low-temperature annealed spin-coated precursor film. Standard CZTSSe thin film solar cell based on the selenized CZTSSe thin film was fabricated and an efficiency of 6.4 % was achieved. PMID:26293494

  5. Solution-Processed Cu2ZnSn(S,Se)4 Thin-Film Solar Cells Using Elemental Cu, Zn, Sn, S, and Se Powders as Source

    Science.gov (United States)

    Guo, Jing; Pei, Yingli; Zhou, Zhengji; Zhou, Wenhui; Kou, Dongxing; Wu, Sixin

    2015-08-01

    Solution-processed approach for the deposition of Cu2ZnSn (S,Se)4 (CZTSSe) absorbing layer offers a route for fabricating thin film solar cell that is appealing because of simplified and low-cost manufacturing, large-area coverage, and better compatibility with flexible substrates. In this work, we present a simple solution-based approach for simultaneously dissolving the low-cost elemental Cu, Zn, Sn, S, and Se powder, forming a homogeneous CZTSSe precursor solution in a short time. Dense and compact kesterite CZTSSe thin film with high crystallinity and uniform composition was obtained by selenizing the low-temperature annealed spin-coated precursor film. Standard CZTSSe thin film solar cell based on the selenized CZTSSe thin film was fabricated and an efficiency of 6.4 % was achieved.

  6. A study of the applicability of ZnO thin-films as anti-reflection coating on Cu{sub 2}ZnSnS{sub 4} thin-films solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Ray, Abhijit; Patel, Malkeshkumar; Tripathi, Brijesh; Kumar, Manoj [School of Solar Energy, Panditdeendayal Petroleum University, Raisan, Gandhinagar, Gujarat (India)

    2012-06-25

    Transparent ZnO thin-films are prepared using the RF magnetron sputtering and spray pyrolysis techniques on the glass substrates. Reflectance spectra and thin films heights are measured using spectrophotometer and stylus surface profiler, respectively. Measured optical data is used for investigating the effect of the ZnO prepared by above two processes on the performance of Cu{sub 2}ZnSnS{sub 4} (CZTS) thin films solar cell (TFSC). One dimensional simulation approach is considered using the simulation program, SCAPS. External quantum efficiency and J-V characteristics of CZTS TFSC is simulated on the basis of optical reflectance data of ZnO films with and without ZnO thin-films as antireflection coating (ARC). Study shows that ARC coated CZTS TFSC provides a better fill factor (FF) as compared to other ARC material such as MgF{sub 2}. Sprayed ZnO thin-films as ARC show comparable performance with the sputtered samples.

  7. Nanostructured p-type CZTS thin films prepared by a facile solution process for 3D p-n junction solar cells

    Science.gov (United States)

    Park, Si-Nae; Sung, Shi-Joon; Sim, Jun-Hyoung; Yang, Kee-Jeong; Hwang, Dae-Kue; Kim, Junho; Kim, Gee Yeong; Jo, William; Kim, Dae-Hwan; Kang, Jin-Kyu

    2015-06-01

    Nanoporous p-type semiconductor thin films prepared by a simple solution-based process with appropriate thermal treatment and three-dimensional (3D) p-n junction solar cells fabricated by depositing n-type semiconductor layers onto the nanoporous p-type thin films show considerable photovoltaic performance compared with conventional thin film p-n junction solar cells. Spin-coated p-type Cu2ZnSnS4 (CZTS) thin films prepared using metal chlorides and thiourea show unique nanoporous thin film morphology, which is composed of a cluster of CZTS nanograins of 50-500 nm, and the obvious 3D p-n junction structure is fabricated by the deposition of n-type CdS on the nanoporous CZTS thin films by chemical bath deposition. The photovoltaic properties of 3D p-n junction CZTS solar cells are predominantly affected by the scale of CZTS nanograins, which is easily controlled by the sulfurization temperature of CZTS precursor films. The scale of CZTS nanograins determines the minority carrier transportation within the 3D p-n junction between CZTS and CdS, which are closely related with the photocurrent of series resistance of 3D p-n junction solar cells. 3D p-n junction CZTS solar cells with nanograins below 100 nm show power conversion efficiency of 5.02%, which is comparable with conventional CZTS thin film solar cells.Nanoporous p-type semiconductor thin films prepared by a simple solution-based process with appropriate thermal treatment and three-dimensional (3D) p-n junction solar cells fabricated by depositing n-type semiconductor layers onto the nanoporous p-type thin films show considerable photovoltaic performance compared with conventional thin film p-n junction solar cells. Spin-coated p-type Cu2ZnSnS4 (CZTS) thin films prepared using metal chlorides and thiourea show unique nanoporous thin film morphology, which is composed of a cluster of CZTS nanograins of 50-500 nm, and the obvious 3D p-n junction structure is fabricated by the deposition of n-type CdS on the nanoporous CZTS thin films by chemical bath deposition. The photovoltaic properties of 3D p-n junction CZTS solar cells are predominantly affected by the scale of CZTS nanograins, which is easily controlled by the sulfurization temperature of CZTS precursor films. The scale of CZTS nanograins determines the minority carrier transportation within the 3D p-n junction between CZTS and CdS, which are closely related with the photocurrent of series resistance of 3D p-n junction solar cells. 3D p-n junction CZTS solar cells with nanograins below 100 nm show power conversion efficiency of 5.02%, which is comparable with conventional CZTS thin film solar cells. Electronic supplementary information (ESI) available: DETAILS. See DOI: 10.1039/c5nr02081f

  8. Enhanced photovoltaic performances of graphene/Si solar cells by insertion of a MoS2 thin film

    Science.gov (United States)

    Tsuboi, Yuka; Wang, Feijiu; Kozawa, Daichi; Funahashi, Kazuma; Mouri, Shinichiro; Miyauchi, Yuhei; Takenobu, Taishi; Matsuda, Kazunari

    2015-08-01

    Transition-metal dichalcogenides exhibit great potential as active materials in optoelectronic devices because of their characteristic band structure. Here, we demonstrated that the photovoltaic performances of graphene/Si Schottky junction solar cells were significantly improved by inserting a chemical vapor deposition (CVD)-grown, large MoS2 thin-film layer. This layer functions as an effective electron-blocking/hole-transporting layer. We also demonstrated that the photovoltaic properties are enhanced with the increasing number of graphene layers and the decreasing thickness of the MoS2 layer. A high photovoltaic conversion efficiency of 11.1% was achieved with the optimized trilayer-graphene/MoS2/n-Si solar cell.Transition-metal dichalcogenides exhibit great potential as active materials in optoelectronic devices because of their characteristic band structure. Here, we demonstrated that the photovoltaic performances of graphene/Si Schottky junction solar cells were significantly improved by inserting a chemical vapor deposition (CVD)-grown, large MoS2 thin-film layer. This layer functions as an effective electron-blocking/hole-transporting layer. We also demonstrated that the photovoltaic properties are enhanced with the increasing number of graphene layers and the decreasing thickness of the MoS2 layer. A high photovoltaic conversion efficiency of 11.1% was achieved with the optimized trilayer-graphene/MoS2/n-Si solar cell. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr03046c

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

    International Nuclear Information System (INIS)

    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 ?m. 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. (paper)

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

    Science.gov (United States)

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

    2014-03-01

    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 ?m. 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.

  11. Scattering matrix analysis for evaluating the photocurrent in hydrogenated-amorphous-silicon-based thin film solar cells.

    Science.gov (United States)

    Shin, Myunghun; Lee, Seong Hyun; Lim, Jung Wook; Yun, Sun Jin

    2014-11-01

    A scattering matrix (S-matrix) analysis method was developed for evaluating hydrogenated amorphous silicon (a-Si:H)-based thin film solar cells. In this approach, light wave vectors A and B represent the incoming and outgoing behaviors of the incident solar light, respectively, in terms of coherent wave and incoherent intensity components. The S-matrix determines the relation between A and B according to optical effects such as reflection and transmission, as described by the Fresnel equations, scattering at the boundary surfaces, or scattering within the propagation medium, as described by the Beer-Lambert law and the change in the phase of the propagating light wave. This matrix can be used to evaluate the behavior of angle-incident coherent and incoherent light simultaneously, and takes into account not only the light scattering process at material boundaries (haze effects) but also nonlinear optical processes within the material. The optical parameters in the S-matrix were determined by modeling both a 2%-gallium-doped zinc oxide transparent conducting oxide and germanium-compounded a-Si:H (a-SiGe:H). Using the S-matrix equations, the photocurrent for an a-Si:H/a-SiGe:H tandem cell and the optical loss in semitransparent a-Si:H solar cells for use in building-integrated photovoltaic applications were analyzed. The developed S-matrix method can also be used as a general analysis tool for various thin film solar cells. PMID:25958519

  12. Optimized Packing Density of Large CZTS Nanoparticles Synthesized by Hot-injection for Thin Film Solar Cells

    DEFF Research Database (Denmark)

    Engberg, Sara Lena Josefin; Lam, Yeng Ming; Schou, Jørgen

    2015-01-01

    The absorbing kesterite material, Cu2ZnSn(SxSe1-x)4 (CZTS), is very promising for future thin film solar cells. The material is non-toxic, the elements abundant, and it has a high absorption coefficient. These properties make CZTS a potential candidate also for large-scale applications. Here, solution processing allows for comparatively fast and inexpensive fabrication, and also holds the record efficiency in the kesterite family. Unfortunately, the record cell is deposited with a highly toxic s...

  13. Sulfur-doped nickel oxide thin film as an alternative to Pt for dye-sensitized solar cell counter electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Guai, Guan Hong [Center for Advanced Bionanosystems and School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore 637457 (Singapore); GlobalFoundries Singapore Pte. Ltd., 60 Woodlands Industrial Park D, Street 2, Singapore 738406 (Singapore); Leiw, Ming Yian [GlobalFoundries Singapore Pte. Ltd., 60 Woodlands Industrial Park D, Street 2, Singapore 738406 (Singapore); School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Ng, Chee Mang [GlobalFoundries Singapore Pte. Ltd., 60 Woodlands Industrial Park D, Street 2, Singapore 738406 (Singapore); Li, Chang Ming [Center for Advanced Bionanosystems and School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore 637457 (Singapore); Institute for Clean Energy and Advanced Materials, Southwest University, Chongqing 400715 (China)

    2012-03-15

    A low-cost, sulfur-doped NiO (S-NiO) thin film is electrodeposited on fluorine-doped SnO{sub 2} substrate and studied in an iodide-based redox system. High electrochemical activity is present because of a large catalytic surface area and a low charge transfer resistance. A dye- sensitized solar cell with a low-loaded S-NiO counter electrode achieves a power conversion efficiency of 5.04%, close to that of a cell with a conventional platinized electrode. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

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

    International Nuclear Information System (INIS)

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

  15. Microstructural and optical properties of CuIn{sub 3}Te{sub 5} thin films for solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Mise, Takahiro; Nakada, Tokio [Department of Electrical Engineering and Electronics, Aoyama Gakuin University, 5-10-1 Fuchinobe, Sagamihara, Kanagawa, 229-8558 (Japan)

    2010-06-15

    CuIn{sub 3}Te{sub 5} thin films were deposited onto soda-lime glass (SLG) substrates by using a molecular beam epitaxy (MBE) system. Microstructural properties were examined by means of scanning electron microscopy (SEM), X-ray diffraction (XRD) and Raman scattering. The substrate temperature (T{sub sub}) dependence of film properties was investigated in the range of 100-400 C. Large-grain CuIn{sub 3}Te{sub 5} thin films with a defect chalcopyrite structure were dominantly grown at 200-400 C. Preferred (1 1 2) orientation was observed even at the low substrate temperature of 200 C. The optical bandgaps of these films were determined to be 1.01-1.05 eV from transmission and reflection measurements. The best solar cell fabricated using CuIn{sub 3}Te{sub 5} thin films grown at 200 C yielded an efficiency of 4.64% with V{sub oc}=318 mV, J{sub sc}=29.0 mA/cm{sup 2} and FF=0.504. (author)

  16. Impact of contamination on hydrogenated amorphous silicon thin films and solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Woerdenweber, Jan

    2011-09-26

    This thesis deals with atmospheric contamination and cross-contamination of boron (single-chamber process) of the intrinsic absorber layer (i-layer) of p-i-n thin film solar cells based on hydrogenated amorphous silicon. The atmospheric contaminations were introduced by means of intentional leaks. Hereby, the focus is on the influence of contamination species (oxygen and nitrogen), quantity of contamination (leak flow), source of contamination (leaks at chamber wall or in the process gas pipe), and plasma power on the properties of solar cells. Thereby, the minimum requirements for the purity of vacuum and process gas as well as leak conditions of the recipient and gas pipe system have been determined. Additionally, deposition regimes were developed, where the incorporation of impurities is significantly suppressed. For standard processes critical levels of nitrogen and oxygen contamination are determined to be {proportional_to} 4 x 10{sup 18} cm{sup -3} and {proportional_to} 2 x 10{sup 19} cm{sup -3}, respectively, for a leak situated at the chamber wall. Above these concentrations the solar cell efficiency deteriorates. In literature, incorporation of oxygen and nitrogen in doping configuration is assumed to be the reason for the cell deterioration. This assumption is supported by additional material studies of contaminated absorber layers done in this work. The difference in critical concentration is due to the higher doping efficiency of nitrogen compared to that for oxygen. Nevertheless, applying an air leak the critical concentrations of O and N are reached almost simultaneously since the incorporation probability of oxygen is about one order of magnitude higher compared to that for nitrogen. Applying a leak in the process gas pipe the critical oxygen contamination level increases to {proportional_to} 2 x 10{sup 20} cm{sup -3} whereas the critical nitrogen level remains unchanged compared to a chamber wall leak. Applying a deposition regime with a very high flow of process gases for oxygen the higher critical contamination level is found as well for a chamber wall leak. Possible reasons for the dependence of the critical oxygen contamination on the deposition regime and the oxygen source may be the following. Before entering the plasma zone the oxygen can react with hydrogen atoms, silane (very high reaction probability), or silane radicals. Mainly, three reaction products may result, namely SiO{sub 2}-clusters, siloxane (SiH{sub 3}-O-SiH{sub 3}), and OH / H{sub 2}O molecules. The SiO{sub 2} is assumed to drop to the bottom of the reactor or to be pumped out. If oxygen is incorporated from siloxane, it is assumed to be electrically inactive. In contrast, oxygen incorporated from hydrogen-oxygen molecules leads to oxygen incorporation in an electrically active configuration. For a source gas pipe leak, the density of silane in the gas pipe is high compared to that for the chamber wall leak. For the chamber wall leak the hydrogen density is assumed to be much higher compared to that for the process gas pipe leak. Thus, the critical oxygen concentration is suggested to increases due to the resulting higher siloxane to OH / H{sub 2}O ratio for the gas pipe leak compared to that in the vicinity of the chamber wall leak. The different critical levels for different deposition regimes can be explained by their oxygen incorporation velocity. The lifetime of the OH / H{sub 2}O molecules is assumed to be shorter, compared to that for the siloxane. As a consequence this might lead to the fact, that oxygen form these molecules is incorporated in one regime (fast incorporation), and in another regime it is not incorporated (slow incorporation). For nitrogen the same critical contamination levels are observed which is attributed to the lack of reactivity of silane and nitrogen. The observed critical impurity concentrations do not change after light-soaking experiments of the solar cells. A further aspect of this thesis is to improve the single-chamber process for the fabrication of amorphous hydrogenated silicon thin-film solar c

  17. ZnO thin films fabricated by chemical bath deposition, used as buffer layer in organic solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Lare, Y. [Laboratoire sue l' Energie Solaire, Universite de Lome, Lome (Togo); Godoy, A. [Facultad Ciencias de la Salud, Universidad Diego Portales, Ejercito 141, Santiago de Chile (Chile); Cattin, L. [Universite de Nantes, Nantes Atlantique Universites, IMN, Faculte des Sciences et des Techniques, 2 rue de la Houssiniere, BP 92208, Nantes, F-44000 France (France); Jondo, K. [Laboratoire sue l' Energie Solaire, Universite de Lome, Lome (Togo); Abachi, T. [Ecole Normale Superieure, Kouba, Alger (Algeria); Diaz, F.R. [Laboratorio de Polimeros, Facultad de Quimica, Pontificia Universidad Catolica de Chile, Casilla 306, Correo 22, Santiago (Chile); Morsli, M. [Universite de Nantes, Nantes Atlantique Universites, LAMP, EA 3825, Faculte des Sciences et des Techniques, 2 rue de la Houssiniere, BP 92208, Nantes, F-44000 France (France); Napo, K. [Laboratoire sue l' Energie Solaire, Universite de Lome, Lome (Togo); del Valle, M.A. [Laboratorio de Polimeros, Facultad de Quimica, Pontificia Universidad Catolica de Chile, Casilla 306, Correo 22, Santiago (Chile); Bernede, J.C., E-mail: jean-christian.bernede@univ-nantes.fr [Universite de Nantes, Nantes Atlantique Universites, LAMP, EA 3825, Faculte des Sciences et des Techniques, 2 rue de la Houssiniere, BP 92208, Nantes, F-44000 France (France)

    2009-04-15

    ZnO thin films synthetized by chemical bath deposition are used as buffer layer between the anode and the organic electron donor in organic solar cells. Films deposited from zinc nitrate solutions are annealed in room air at 300 deg. C for half an hour. The X-ray diffraction and microanalysis studies show that ZnO polycrystalline thin films are obtained. The solar cells used are based on the couple copper phthalocyanine as electron donor and (N,N-diheptyl-3,4,9,10-perylenetetracarboxylicdiimide-PTCDI-C7) as electron acceptor. It is shown that the presence of the ZnO buffer layer improves the energy conversion efficiency of the cells. Such improvement could be attributed to a better energy level alignment at the anode/electron donor interface. The anode roughness induced by the ZnO buffer layer can also transform the planar interface organic electron donor/electron acceptor into roughen topography. This increases the interface area, where carrier separation takes place, which improves solar cells performances.

  18. A comparative study on the performance of Kesterite based thin film solar cells using SCAPS simulation program

    Science.gov (United States)

    Simya, O. K.; Mahaboobbatcha, A.; Balachander, K.

    2015-06-01

    A comparative study of thin film solar cells based on CZTS, CZTSe, and CZTSSe (Copper Zinc Tin Sulphur Selenium) absorbers layers were simulated with Cadmium Sulphide (CdS) as buffer layer and Zinc Oxide (ZnO) as window layer using a solar cell capacitance simulator (SCAPS). The influences of series resistance, band to band recombination, defects and interfaces, thickness of (CZTS|CZTSe|CZTSSe) absorber layer, (CdS) buffer layer and transparent conductive oxide layer (ZnO) on the photovoltaic cell parameters were studied in detail. Improvements in efficiency were achieved by changing the back contact metal work function (BMWF) and choosing the flat band option in SCAPS software. Based on the best possible optimisation, an efficiency (?) of 12.03%, 13.16% and 15.77% were obtained for CZTS, CZTSe, and CZTSSe respectively. The performance of thin film photovoltaic devices (TFPV), for Mo back contact before optimisation and the SCAPS simulated values (flat band) after optimisation were described in detail to have in-depth understanding for better design of experiments (DOE) to obtain high efficiency solar cells.

  19. A comparative study of solution-processed low- and high-band-gap chalcopyrite thin-film solar cells

    International Nuclear Information System (INIS)

    Low-cost and printable chalcopyrite thin-film solar cells were fabricated by a precursor solution-based coating method with a multi-step heat-treatment process (oxidation, sulfurization, and selenization). The high-band-gap (1.57 eV) Cu(InxGa1?x)S2 (CIGS) solar cell showed a high open-circuit voltage of 787 mV, whereas the low-band-gap (1.12 eV) Cu(InxGa1?x)(S1?ySey)2 (CIGSSe) cell exhibited a high short-circuit current density of 32.6 mA cm?2. The energy conversion efficiencies were 8.28% for CIGS and 8.81% for CIGSSe under standard irradiation conditions. Despite similar efficiencies, the two samples showed notable differences in grain size, surface morphology, and interfacial properties. Low-temperature transport and admittance characteristics of the samples clearly revealed how their structural differences influenced their photovoltaic and electrical properties. Such analyses provide insight into the enhanced solar cell performance of the solution-processed chalcopyrite thin films. (paper)

  20. Enhancement of Conversion Efficiency of Cu2ZnSnS4 Thin Film Solar Cells by Improvement of Sulfurization Conditions

    Science.gov (United States)

    Fukano, Tatsuo; Tajima, Shin; Ito, Tadayoshi

    2013-06-01

    To enhance the conversion efficiency of Cu2ZnSnS4 (CZTS) thin film solar cells prepared by the sulfurization method, we investigated the formation process of the CZTS thin film. The holding temperature of the sulfurization was 580 °C. This study showed that the spreading resistance (SR) of the CZTS layer strongly depends on the holding time of the sulfurization. At the intermediate holding time (˜30 min), the SR of the CZTS layer came to a minimum, and the efficiency of the CZTS solar cell came to a maximum. A 7.6% efficiency CZTS solar cell without a high-resistance buffer layer and an antireflection coating was fabricated.

  1. Solution-processed highly efficient Cu2ZnSnSe4 thin film solar cells by dissolution of elemental Cu, Zn, Sn, and Se powders.

    Science.gov (United States)

    Yang, Yanchun; Wang, Gang; Zhao, Wangen; Tian, Qingwen; Huang, Lijian; Pan, Daocheng

    2015-01-14

    Solution deposition approaches play an important role in reducing the manufacturing cost of Cu2ZnSnSe4 (CZTSe) thin film solar cells. Here, we present a novel precursor-based solution approach to fabricate highly efficient CZTSe solar cells. In this approach, low-cost elemental Cu, Zn, Sn, and Se powders were simultaneously dissolved in the solution of thioglycolic acid and ethanolamine, forming a homogeneous CZTSe precursor solution to deposit CZTSe nanocrystal thin films. Based on high-quality CZTSe absorber layer, pure selenide CZTSe solar cell with a photoelectric conversion efficiency of 8.02% has been achieved without antireflection coating. PMID:25494493

  2. Simulation of nanostructure-based and ultra-thin film solar cell devices beyond the classical picture

    CERN Document Server

    Aeberhard, Urs

    2014-01-01

    In this paper, an optoelectronic device simulation framework valid for arbitrary spatial variation of electronic potentials and optical modes, and for transport regimes ranging from ballistic to diffusive, is used to study non-local photon absorption, photocurrent generation and carrier extraction in ultra-thin film and nanostructure-based solar cell devices at the radiative limit. Among the effects that are revealed by the microscopic approach and which are inaccessible to macroscopic models is the impact of structure, doping or bias induced nanoscale potential variations on the local photogeneration rate and the photocarrier transport regime.

  3. Natural Sensitizer for Dye-Sensitized Solar Cells Using Three Layers of Photoelectrode Thin Films with a Schottky Barrier

    OpenAIRE

    Ho Chang; Mu-Jung Kao; Tien-Li Chen; Hin-Guo Kuo; Kun-Ching Choand; Xiu-Ping Lin

    2011-01-01

    Problem statement: This study combines Au nanoparticles with TiO2 nanoparticles to form a Schottky barrier and applies it to the photo electrode thin film of Dye-Sensitized Solar Cells (DSSCs). Approach: First, commercial TiO2 powder (Degussa P25) was put into the alkaline solution to prepare TiO nano tubes (Tnt) by a hydrothermal process. Tnt were sintered at 550° to obtain TntC550 particles and fabricated into a translucent sol by two hydrothermal treatments and ...

  4. Design of a wideband multilayer grating spectrometer for the study of electronic structure of thin-film CIS solar cells

    International Nuclear Information System (INIS)

    A soft x-ray emission spectrometer equipped with a wideband Ni/C multilayer-coated laminar-type varied-line-spacing holographic grating is designed to analyze the electronic structure in thin-film copper indium selenide (CIS) solar cells nondestructively by soft x-ray emission spectroscopy. The spectrometer equipped with the multilayer grating thus designed allows us to detect the L emission lines of Cu, In, and Se simultaneously from a CIS absorber layer in the 1–3.5 keV range at a constant angle of incidence. (author)

  5. ZnO nanorod arrays for highly efficient thin film a-Si and micromorph solar cells.

    Czech Academy of Sciences Publication Activity Database

    Neykova, Neda; Hruška, Karel; Remeš, Zden?k; Van??ek, Milan

    Roma : University of Roma Tor Vergata, 2012 - (DE Crescenzi, M.). s. 75-75 [International Conference on NANO-structures self - assembly - NANOSEA 2012 /4./. 25.06.2012-29.06.2012, S. Margherita di Pula - Sardinie] R&D Projects: GA ?R(CZ) GAP108/11/0937 Grant ostatní: FP7(XE) CP-IP 214134-2 Institutional research plan: CEZ:AV0Z10100521 Keywords : ZnO nanocolumns * thin film solar cells * EBL Subject RIV: BM - Solid Matter Physics ; Magnetism

  6. Rapid Thermal Annealing and Hydrogen Passivation of Polycrystalline Silicon Thin-Film Solar Cells on Low-Temperature Glass

    OpenAIRE

    Armin G. Aberle; Daniel Inns; Mason L. Terry

    2007-01-01

    The changes in open-circuit voltage (Voc), short-circuit current density (Jsc), and internal quantum efficiency (IQE) of aLuminum induced crystallization, ion-assisted deposition (ALICIA) polycrystalline silicon thin-film solar cells on low-temperature glass substrates due to rapid thermal anneal (RTA) treatment and subsequent remote microwave hydrogen plasma passivation (hydrogenation) are examined. Voc improvements from 130 mV to 430 mV, Jsc improvements from 1.2 mA/c...

  7. Fabrication of Thin-Film Polycrystalline Silicon Solar Cells by Silane-Gas-Free Process Using Aluminum-Induced Crystallization

    Science.gov (United States)

    Ito, Tadashi; Fukushima, Hideoki; Yamaguchi, Masafumi

    2003-04-01

    The authors have proposed a silane-gas-free fabrication process for thin-film polycrystalline Si solar cells. The process includes formation of a polycrystalline Si seed layer by aluminum-induced crystallization (AIC), crystallization of a Si film formed by physical vapor deposition (PVD) techniques for a base layer, aluminum diffusion from the AIC-grown Si (AIC-Si) layer to the base layer and pn-junction formation by the spin-on-glass technique. The crystal grains grew to a size of ˜20 ?m in diameter through crystallization of the electron-beam-evaporated Si film on the AIC-Si layer, and the carrier lifetime was about 0.6 ?s. In the solar cell fabricated by this process, the AIC-Si layer acts as a back-surface-field (BSF) layer, and the energy band is also inclined in its base layer so that the minority carriers can be pushed back to the depletion layer. These features indicate the possibility of fabricating low-cost and high-efficiency thin-film polycrystalline Si solar cells. The issues that must be pursued to realize high efficiency are reduction of oxygen atom inclusions during Si film deposition, passivation of the grain boundaries and development of a deposition technique for Si films having intermediate packing densities between those of electron-beam-evaporated films and sputter-deposited films, to prevent crack formation when the Si films are crystallized.

  8. Plasmonic back contacts with non-ordered Ag nanostructures for light trapping in thin-film silicon solar cells

    International Nuclear Information System (INIS)

    In this work, we investigate the light trapping of thin-film silicon solar cells which apply plasmonic Ag back contacts with non-ordered Ag nanostructures. The preparation, characterization and three-dimensional electromagnetic simulations of these back contacts with various distributions of non-ordered Ag nanostructures are presented. The measured reflectance spectra of the Ag back contacts with non-ordered nanostructures in air are well reproduced in reflectance spectra derived from the three-dimensional electromagnetic simulations of isolated nanostructures on Ag back contacts. The light–matter interaction of these nanostructures is given by localized surface plasmons and, thus, the measured diffuse reflectance of the back contacts is attributed to plasmon-induced light scattering. A significant plasmonic light-trapping effect in n-i-p substrate-type ?c-Si:H thin-film solar cell prototypes which apply a Ag back contact with non-ordered nanostructures is identified when compared with flat reference solar cells

  9. Radio Frequency Magnetron Sputtering Deposition of TiO2 Thin Films and Their Perovskite Solar Cell Applications

    Science.gov (United States)

    Chen, Cong; Cheng, Yu; Dai, Qilin; Song, Hongwei

    2015-01-01

    In this work, we report a physical deposition based, compact (cp) layer synthesis for planar heterojunction perovskite solar cells. Typical solution-based synthesis of cp layer for perovskite solar cells involves low-quality of thin films, high-temperature annealing, non-flexible devices, limitation of large-scale production and that the effects of the cp layer on carrier transport have not been fully understood. In this research, using radio frequency magnetron sputtering (RFMS), TiO2 cp layers were fabricated and the thickness could be controlled by deposition time; CH3NH3PbI3 films were prepared by evaporation & immersion (E & I) method, in which PbI2 films made by thermal evaporation technique were immersed in CH3NH3I solution. The devices exhibit power conversion efficiency (PCE) of 12.1% and the photovoltaic performance can maintain 77% of its initial PCE after 1440?h. The method developed in this study has the capability of fabricating large active area devices (40?×?40?mm2) showing a promising PCE of 4.8%. Low temperature and flexible devices were realized and a PCE of 8.9% was obtained on the PET/ITO substrates. These approaches could be used in thin film based solar cells which require high-quality films leading to reduced fabrication cost and improved device performance. PMID:26631493

  10. Plasmonic back contacts with non-ordered Ag nanostructures for light trapping in thin-film silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Paetzold, Ulrich W., E-mail: u.paetzold@fz-juelich.de [IEK5-Photovoltaik, Forschungszentrum Juelich, D-52425 Juelich (Germany); Meier, Matthias, E-mail: ma.meier@fz-juelich.de [IEK5-Photovoltaik, Forschungszentrum Juelich, D-52425 Juelich (Germany); Moulin, Etienne, E-mail: e.moulin@fz-juelich.de [IEK5-Photovoltaik, Forschungszentrum Juelich, D-52425 Juelich (Germany); Smirnov, Vladimir, E-mail: v.smirnov@fz-juelich.de [IEK5-Photovoltaik, Forschungszentrum Juelich, D-52425 Juelich (Germany); Pieters, Bart E., E-mail: b.pieters@fz-juelich.de [IEK5-Photovoltaik, Forschungszentrum Juelich, D-52425 Juelich (Germany); Rau, Uwe, E-mail: u.rau@fz-juelich.de [IEK5-Photovoltaik, Forschungszentrum Juelich, D-52425 Juelich (Germany); Carius, Reinhard, E-mail: r.carius@fz-juelich.de [IEK5-Photovoltaik, Forschungszentrum Juelich, D-52425 Juelich (Germany)

    2013-05-15

    In this work, we investigate the light trapping of thin-film silicon solar cells which apply plasmonic Ag back contacts with non-ordered Ag nanostructures. The preparation, characterization and three-dimensional electromagnetic simulations of these back contacts with various distributions of non-ordered Ag nanostructures are presented. The measured reflectance spectra of the Ag back contacts with non-ordered nanostructures in air are well reproduced in reflectance spectra derived from the three-dimensional electromagnetic simulations of isolated nanostructures on Ag back contacts. The light–matter interaction of these nanostructures is given by localized surface plasmons and, thus, the measured diffuse reflectance of the back contacts is attributed to plasmon-induced light scattering. A significant plasmonic light-trapping effect in n-i-p substrate-type ?c-Si:H thin-film solar cell prototypes which apply a Ag back contact with non-ordered nanostructures is identified when compared with flat reference solar cells.

  11. Silicon-Light: a European FP7 Project Aiming at High Efficiency Thin Film Silicon Solar Cells on Foil

    DEFF Research Database (Denmark)

    Soppe, W.; Haug, F.-J.

    2011-01-01

    Silicon-Light is a European FP7 project, which started January 1st, 2010 and aims at development of low cost, high-efficiency thin film silicon solar cells on foil. Three main routes are explored to achieve these goals: a) advanced light trapping by implementing nanotexturization through UV Nano Imprinting Lithography (UV-NIL); b) growth of crack-free silicon absorber layers on highly textured substrates; c) development of new TCOs which should combine the best properties of presently available materials like ITO and AZO. The paper presents the midterm status of the project results, showing model calculations of ideal nanotextures for light trapping in thin film silicon solar cells; the fabrication of masters and the replication and roll-to-roll fabrication of these nanotextures. Further, results on ITO variants with improved work function are presented. Finally, the status of cell fabrication on foils with nanotexture is shown. Microcrystalline and amorphous silicon single junction cells with stable efficiencies with more than 8 % have been made, paving the way towards a-Si/ c-Si tandem cells with more than 11% efficiency.

  12. 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 ? = 9.55% under simulated AM 1.5 100 mW cm(-2) illuminations, without the use of an antireflection layer. This demonstrates the potential of ESAVD deposition as a promising alternative approach for making thin film CIGSSe solar cells at a lower cost. PMID:26390182

  13. Nanoimprinted backside reflectors for a-Si:H thin-film solar cells: critical role of absorber front textures.

    Science.gov (United States)

    Tsao, Yao-Chung; Fisker, Christian; Pedersen, Thomas Garm

    2014-05-01

    The development of optimal backside reflectors (BSRs) is crucial for future low cost and high efficiency silicon (Si) thin-film solar cells. In this work, nanostructured polymer substrates with aluminum coatings intended as BSRs were produced by positive and negative nanoimprint lithography (NIL) techniques, and hydrogenated amorphous silicon (a-Si:H) was deposited hereon as absorbing layers. The relationship between optical properties and geometry of front textures was studied by combining experimental reflectance spectra and theoretical simulations. It was found that a significant height variation on front textures plays a critical role for light-trapping enhancement in solar cell applications. As a part of sample preparation, a transfer NIL process was developed to overcome the problem of low heat deflection temperature of polymer substrates during solar cell fabrication. PMID:24922373

  14. Structural and optical properties of electrodeposited culnSe2 thin films for photovoltaic solar cells

    International Nuclear Information System (INIS)

    Optical an structural properties of electrodeposited copper indium diselenide, CulnSe2, thin films were studied for its application in photovoltaic devices. X-ray diffraction patterns showed that thin films were grown in chalcopyrite phase after suitable treatments. Values of Eg for the CulnSe2 thin films showed a dependence on the deposition potential as determined by optical measurements. (Author) 47 refs

  15. Theoretical study of quaternary compounds as thin-film solar cell absorber

    International Nuclear Information System (INIS)

    Full text : Design of chalcogenide photovoltaic absorbers is carried out systematically through sequential cation mutation, from binary to ternary to quaternary compounds, using first-principles electronic structure calculations. Several universal trends are found for the ternary and two classes of quaternary chalcogenides. For example, the lowest-energy structure always has larger lattice constant a, smaller tetragonal distortion parameter ?=c/2a, and larger band gap than the metastable structures for common-row cation mutations. The band gap is reduced during the mutation. The band gap decreases from binary II-VI to ternary I-III-VI2 are mostly due to the p-d repulsion in the valence band, the decreases from ternary I-III-VI2 to quaternary I2-II-IV-VI4 chalcogenides are due to the downshift in the conduction band caused by the wavefunction localization on the group IV cation site. It was found that I2-II-IV-VI4 compounds are more stable in the kesterite structure, whereas the widely-assumed stannite structure reported in the literature is most likely due to partial disorder in the I-II layer of the kesterite phase. Among the derived quaternary compounds, Cu2ZnSnS4 (CZTS) is one of the ideal candidate absorber materials for thin-film solar cells with an optimal band gap, high absorption coefficient, abundant elemental components, and is adaptable to various growth techniques. It was performed a series of first-principles electronic structure calculations for CZTS. Also it was found that in the ground state kesterite structure, (i) the chemical potential region that CZTS can form is very small. Therefore, it will be very difficult to obtain high quality stoichiometric CZTS samples; (ii) The dominant p-type acceptor in CZTS is CuZn, however, the associated acceptor level is relatively high, suggesting that p-type doping in CZTS is more difficult than ternary compounds such as CuInSe2; (iii) The formation of the self-compensated defect pair [CuZn+ZnCu] will not lead to a strong carrier separation, and thus will not contribute the same beneficial effect observed in ternary chalcopyrite compounds; (iv) We predict that to avoid the aforementioned issues in (ii) and (iii), it will be optimal to grow the sample under Cu-poor/Zn-rich conditions, so VCu and ZnCu become the dominant defects in the system. However, in this case, non-equilibrium growth techniques may be required to avoid the formation of secondary phases. All predictions will be compared with available experiments

  16. Analysis of radiation resistance of InGaP/GaAs dual-junction thin-film space solar cell

    International Nuclear Information System (INIS)

    Thin-film III-V multi-junction solar cells can realize the advantages of being high-efficiency and light-weight, as such these cells meets the requirement for higher specific power and lower stowage volume solar panels. Here we report the development results of an InGaP/GaAs thin-film dual-junction (TF2J) solar cell. In this paper, we study the radiation resistance of the TF2J cells with efficiency of 20-23% under AM0.1 sun at 25degC. The cells were subjected to proton irradiation with an energy range of 100keV-10MeV. The results were compared with the radiation resistance of a conventional InGaP/GaAs/Ge triple-junction (3J) cell. In the proton energy range of 200-400keV, radiation resistance of the TF2J cell is superior to that of the 3J cell. Particularly, the 1sc of the TF2J cell is significantly higher than that of the 3J cell after exposure to 380keV protons, which results in higher remaining factor of Pmax for the TF2J cell. In additions, Voc of the cells after the irradiations are almost equivalent, even though the TF2J cell is a dual-junction structure. The higher 1sc of the TF2J cell after irradiation is due to higher radiation resistance of the GaAs subcell according to the comparison of the spectral response. (author)

  17. Electrodeposited ZnS Precursor Layer with Improved Electrooptical Properties for Efficient Cu2ZnSnS4 Thin-Film Solar Cells

    Science.gov (United States)

    Mkawi, E. M.; Ibrahim, K.; Ali, M. K. M.; Farrukh, M. A.; Mohamed, A. S.

    2015-10-01

    Zinc sulfide (ZnS) thin films were prepared on indium tin oxide-coated glass by electrodeposition using aqueous zinc sulfate, thiourea, and ammonia solutions at 80°C. The effects of sulfurization at temperatures of 350°C, 400°C, 450°C, and 500°C on the morphological, structural, optical, and electrical properties of the ZnS thin films were investigated. X-ray diffraction analysis showed that the ZnS thin films exhibited cubic zincblende structure with preferred (111) orientation. The film crystallization improved with increasing annealing temperature. Field-emission scanning electron microscopy images showed that the film morphology became more compact and uniform with increasing annealing temperature. The percentage of sulfur in the ZnS thin films increased after sulfurization until a stoichiometric S/Zn ratio was achieved at 500°C. The annealed films showed good adhesion to the glass substrates, with moderate transmittance (85%) in the visible region. Based on absorption measurements, the direct bandgap increased from 3.71 eV to 3.79 eV with annealing temperature, which is attributed to the change of the buffer material composition and suitable crystal surface properties for effective p- n junction formation. The ZnS thin films were used as a buffer layer in thin-film solar cells with the structure of soda-lime glass/Mo/Cu2ZnSnS4/ZnS/ZnO/Al grid. The best solar cell efficiency was 1.86%.

  18. Fabrication of Cu2SnS3 thin-film solar cells with power conversion efficiency of over 4%

    Science.gov (United States)

    Kanai, Ayaka; Toyonaga, Kotoba; Chino, Kotaro; Katagiri, Hironori; Araki, Hideaki

    2015-08-01

    Cu2SnS3 (CTS) thin films were produced by the co-evaporation of Cu, Sn, and cracked sulfur, followed by annealing. The as-deposited films were then annealed at 570 °C for 5 min in the presence of 100 mg of sulfur lumps in a rapid thermal processing furnace filled with N2 gas at atmospheric pressure. Solar cells were then fabricated using the CTS films as absorber layers, and their efficiency was evaluated for different Cu/Sn compositional ratios. The largest grain size was found for films with a slightly Sn-rich composition. The highest performance was obtained for solar cells containing a CTS thin film with a Cu/Sn ratio of about 1.9. A cell with a Cu/Sn ratio of 1.87 exhibited an open-circuit voltage of 258 mV, a short-circuit current density of 35.6 mA/cm2, a fill factor of 0.467, and a power conversion efficiency of 4.29%.

  19. Multilayer nanoparticle arrays for broad spectrum absorption enhancement in thin film solar cells

    CERN Document Server

    Krishnan, Aravind; Krishna, Siva Rama; Khan, Mohammed Zafar Ali

    2013-01-01

    In this paper, we present a theoretical study on the absorption efficiency enhancement of a thin film amorphous Silicon (a-Si) photovoltaic cell over a broad spectrum of wavelengths using multiple nanoparticle arrays. The light absorption efficiency is enhanced in the lower wavelengths by a nanoparticle array on the surface and in the higher wavelengths by another nanoparticle array embedded in the active region. The efficiency at intermediate wavelengths is enhanced by the constructive interference of plasmon coupled light. We optimize this design by tuning the radius of particles in both arrays, the period of the array and the distance between the two arrays. The optimization results in 61.44% increase in total quantum efficiency for a 500 nm thick a-Si substrate.

  20. Broadband grating couplers for efficient thin film solar cells. Final report; Breitband-Gitterkoppler fuer effiziente Duennschichtsolarzellen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Stutzmann, M.; Nebel, C.E.; Eisele, C.; Klein, S.; Carius, R.; Finger, F.; Schubert, M.

    2002-08-01

    Efficient thin film solar cells usually require a dedicated light trapping strategy in order to achieve an optimum absorption of the solar spectrum. At present, mainly statistically textured transparent conducting electrodes are used for this purpose (TCO layers, e.g. ZnO). One aim of this project was the preparation and characterization of microstructured periodic grating couplers for the efficient trapping of weakly absorbed light in silicon thin film cells. In addition, a preliminary investigation concerning the feasibility of thin SiGe-alloy films on glass as an alternative absorber layer for tandem solar cells was to be performed. Periodically structured TCO electrodes were prepared by holographic laser patterning. These electrode layers are transparent up to the UV spectral range and can be easily structured into sub-micron gratings using HCl etching. In cooperation with the Institute for Photovoltaics (IPV), the resulting light trapping structures were overgrown by amorphous silicon solar cells using PECVD. The electrical and optical properties of these solar cells with integrated grating couplers were investigated in a systematic way, with special emphasis on the possible enhancement of the internal electric field caused by the microstructure. In addition, the growth of amorphous and microcrystalline silicon solar cell structures by hot wire CVD on both, structured as well as unstructured substrates was studied at the IPV. A second part of the project was concerned with the deposition of ultrapure amorphous Si, SiGe, and Ge films on glass by evaporation in an ultra high vacuum, followed by laser recrystallization and hydrogen passivation. For this purpose, a dedicated UHV deposition system was built. The deposited films were recrystallized with a variety of different laser techniques in order to achieve a first optimization of crystallite sizes and electronic properties. Main results of the project: (i) Grating couplers indeed can provide an efficient and tunable means of coupling sunlight into thin film solar cells. While the best results achieved so far do not give rise to a noticeable improvement compared to light trapping strategies based on statistical texture, the transferability of the process developed here to other solar cell structures is an important advantage. (ii) Thin microcrystalline SiGe-layers on glass produced by evaporation and laser crystallization exhibit promising electronic and optical properties with respect to applications as absorber layers in thin film solar cells. However, to this end, a further optimization of the crystallization process and the ensuing material properties will be necessary. (orig.) [German] Fuer Duennschicht-Solarzellen ist im Allgemeinen eine integrierte Lichtfallenstruktur notwendig, um eine moeglichst vollstaendige Absorption des Sonnenspektrums zu erzielen. Gegenwaertig werden hierfuer fast ausschliesslich statistisch texturierte transparente Elektrodenschichten (z.B. aus ZnO) eingesetzt. Ziel dieses Projektes war die Herstellung und Untersuchung mikrostrukturierter periodischer Gitterkoppler zur gezielten Einkopplung schwach absorbierten Lichtes. Zusaetzlich sollten erste Versuche zum Einsatz von kristallinen SiGe-Duennschicht-Filmen auf Glas als stark absorbierendes Halbleitermaterial fuer den Einsatz in Tandem-Solarzellen exploratorisch durchgefuehrt werden. Im Rahmen des Forschungsprojektes wurden strukturierte Elektroden aus TCO hergestellt, die hohe optische Transparenz bis ins UV aufweisen. Zur effizienten Lichteinkopplung wurden erfolgreich Beugungsgitter im Submikrometerbereich hergestellt, die als Lichtfallen wirken. In Zusammenarbeit mit dem Institut fuer Photovoltaik (IPV) wurden diese Lichtfallen in Solarzellen integriert. Die elektrischen und optischen Eigenschaften dieser Solarzellen mit Gitterkoppler-Strukturen wurden systematisch untersucht, insbesondere auch hinsichtlich einer durch die Strukturierung bewirkten internen Feldverstaerkung. Zusaetzlich wurden am Institut fuer Photovoltaik des Forschungszentrums Juelich grundlagenorientierte Untersu

  1. Development of natively textured surface hydrogenated Ga-doped ZnO-TCO thin films for solar cells via magnetron sputtering

    International Nuclear Information System (INIS)

    Highlights: ? Natively textured surface hydrogenated gallium-doped zinc oxide (HGZO) thin films have been deposited via magnetron sputtering on glass substrates. ? The directly deposited HGZO thin films present rough crater-type surface morphology. ? Typical HGZO thin film exhibits a high electron mobility of 41.3 cm2/V s and a relative low sheet resistance of ?7.0 ?. ? These HGZO thin films have high optical transmittances in the visible and near infrared region (?380–1100 nm). ? A gradient H2 growth method for fabricating HGZO thin films has been proposed in magnetron sputtering process. - Abstract: The main purposes are to obtain high quality transparent conductive oxide (TCO) based on zinc oxide (ZnO) thin films with high optical transparency in the visible and near infrared spectral range, high electrical conductivity and good light-scattering capability to enhance the path of the light inside the Si-based thin film solar cells. Natively textured surface hydrogenated gallium-doped ZnO (HGZO) thin films have been deposited via pulsed direct current (DC) magnetron sputtering on glass substrates at a substrate temperature of 553 K. These natively textured HGZO thin films exhibit high optical transmittance (over 80%) in the visible and near infrared region (? = 380–1100 nm) and excellent electrical properties. The optimized HGZO thin film with crater-type textured surface obtained at the hydrogen flow rate of ?2.0 sccm exhibits a high electron mobility of 41.3 cm2/V s and a relatively low sheet resistance of ?7.0 ?. The influences of hydrogen flow rates on the surface morphology, electrical and optical properties of HGZO thin films were investigated in detail. In addition, we put forward a method of gradient H2 growth technique for fabricating HGZO thin films so as to obtain rough surface structure with good light-scattering capability and high electrical conductivity. “Crater-like” surface feature size and optical transmittance can be improved through gradient H2 growth technique.

  2. Fabrication of Cu2ZnSnS4 thin films using oxides nanoparticles ink for solar cell

    Science.gov (United States)

    Chen, Guilin; Yuan, Chenchen; Liu, Jiwan; Huang, Zhigao; Chen, Shuiyuan; Liu, Weifeng; Jiang, Guoshun; Zhu, Changfei

    2015-02-01

    Oxides nanoparticles-based process is one of the successful approaches to CuIn1-xGaxSe2 (CIGS) formation. To explore systematically the possibility of application of the similar methods to high quality Cu2ZnSnS4 (CZTS), an oxides nanoparticles-based process for preparation of CZTS films is described. The CZTS films are prepared by sulfurizing oxides precursor. Thermodynamic appreciation of sulfurization of oxides precursor is first studied. The development of the CZTS formation with increasing temperature is also investigated. Through optimizing the sulfurization, phase-pure CZTS films with very large grains are obtained. The loss of tin can be avoided, due to the stability of oxides. Finally, preliminary CZTS thin-film solar cells with efficiencies of 1.47% have been fabricated. This study provides basis for low-cost and large area CZTS solar cells.

  3. Enhanced photovoltaic performances of graphene/Si solar cells by insertion of a MoS? thin film.

    Science.gov (United States)

    Tsuboi, Yuka; Wang, Feijiu; Kozawa, Daichi; Funahashi, Kazuma; Mouri, Shinichiro; Miyauchi, Yuhei; Takenobu, Taishi; Matsuda, Kazunari

    2015-09-14

    Transition-metal dichalcogenides exhibit great potential as active materials in optoelectronic devices because of their characteristic band structure. Here, we demonstrated that the photovoltaic performances of graphene/Si Schottky junction solar cells were significantly improved by inserting a chemical vapor deposition (CVD)-grown, large MoS2 thin-film layer. This layer functions as an effective electron-blocking/hole-transporting layer. We also demonstrated that the photovoltaic properties are enhanced with the increasing number of graphene layers and the decreasing thickness of the MoS2 layer. A high photovoltaic conversion efficiency of 11.1% was achieved with the optimized trilayer-graphene/MoS2/n-Si solar cell. PMID:26257026

  4. Development of a rapid thermal annealing process for polycrystalline silicon thin-film solar cells on glass

    International Nuclear Information System (INIS)

    In this report, we discuss the influence of rapid thermal annealing (RTA) on the performance of polycrystalline Si (poly-Si) thin-film solar cells on glass where the poly-Si layers are differently prepared. The first part presents a comprehensive study of RTA treatments on poly-Si thin-films made by solid phase crystallization (SPC) (standard material of CSG Solar AG, Thalheim). By varying both plateau temperature (up to 1050 deg. C) and duration (up to 1000 s) of the annealing profile, we determined the parameters for a maximum open-circuit voltage (VOC). In addition, we applied our standard plasma hydrogenation treatment in order to passivate the remaining intra-grain defects and grain boundaries by atomic hydrogen resulting in a further increase of VOC. We found, that the preceding RTA treatment increases the effect of hydrogenation already at comparable low RTA temperatures. The effect on hydrogenation increases significantly with RTA temperature. In a second step we investigated the effect of the RTA and hydrogenation on large-grained poly-Si films based on the epitaxial thickening of poly-Si seed layers.

  5. Ultra-Lightweight Hybrid Thin-Film Solar Cells: A Survey of Enabling Technologies for Space Power Applications

    Science.gov (United States)

    Hepp, Aloysius F.; McNatt, Jeremiah S.; Bailey, Sheila G.; Dickman, John E.; Raffaelle, Ryne P.; Landi, Brian J.; Anctil, Annick; DiLeo, Roberta; Jin, Michael H.-C.; Lee, Chung-Young; Friske, Theresa J.; Sun, Sam-S.; Zhang, Cheng; Choi, S.; Ledbetter, Abram; Seo, Kang; Bonner, Carl E.; Banger, Kulbinder K.; Castro, Stephanie L.; Rauh, David

    2007-01-01

    The development of hybrid inorganic/organic thin-film solar cells on flexible, lightweight, space-qualified, durable substrates provides an attractive solution for fabricating solar arrays with high mass specific power (W/kg). Next generation thin-film technologies may well involve a revolutionary change in materials to organic-based devices. The high-volume, low-cost fabrication potential of organic cells will allow for square miles of solar cell production at one-tenth the cost of conventional inorganic materials. Plastic solar cells take a minimum of storage space and can be inflated or unrolled for deployment. We will explore a cross-section of in-house and sponsored research efforts that aim to provide new hybrid technologies that include both inorganic and polymer materials as active and substrate materials. Research at University of Texas at Arlington focuses on the fabrication and use of poly(isothianaphthene-3,6-diyl) in solar cells. We describe efforts at Norfolk State University to design, synthesize and characterize block copolymers. A collaborative team between EIC Laboratories, Inc. and the University of Florida is investigating multijunction polymer solar cells to more effectively utilize solar radiation. The National Aeronautics and Space Administration (NASA)/Ohio Aerospace Institute (OAI) group has undertaken a thermal analysis of potential metallized substrates as well as production of nanoparticles of CuInS2 and CuInSe2 in good yield at moderate temperatures via decomposition of single-source precursors. Finally, preliminary work at the Rochester Institute of Technology (R.I.T.) to assess the impact on performance of solar cells of temperature and carbon nanotubes is reported. Technologies that must be developed to enable ultra-lightweight solar arrays include: monolithic interconnects, lightweight array structures, and new ultra-light support and deployment mechanisms. For NASA applications, any solar cell or array technology must not only meet weight and AMO efficiency goals, but also must be durable enough to survive launch conditions and space environments.

  6. Loss mechanisms influence on Cu2ZnSnS4/CdS-based thin film solar cell performance

    Science.gov (United States)

    Courel, Maykel; Andrade-Arvizu, J. A.; Vigil-Galán, O.

    2015-09-01

    One of the most important issues in kesterite Cu2ZnSnS4 (CZTS)-based thin film solar cells is low open circuit voltage, which is mainly related to loss mechanisms that take place in both CZTS bulk material and CdS/CZTS interface. A device model for CZTS/CdS solar cell which takes into account loss mechanisms influence on solar cell performance is presented. The simulation results showed that our model is able to reproduce experimental observations reported for CZTS/CdS-based solar cells with the highest conversion efficiencies, measured under room temperature and AM1.5 intensity. The comparison of simulation results to experimental observations demonstrated that among the different loss mechanisms, trap-assisted tunneling losses are the major hurdle to boost open circuit voltage. Under this loss mechanism, a solar cell efficiency enhancement up to 10.2% with CdS donor concentration decrease was reached. Finally, the possible path toward a further solar cell efficiency improvement is discussed.

  7. Polycrystalline-thin-film thermophotovoltaic cells

    Science.gov (United States)

    Dhere, Neelkanth G.

    1996-02-01

    Thermophotovoltaic (TPV) cells convert thermal energy to electricity. Modularity, portability, silent operation, absence of moving parts, reduced air pollution, rapid start-up, high power densities, potentially high conversion efficiencies, choice of a wide range of heat sources employing fossil fuels, biomass, and even solar radiation are key advantages of TPV cells in comparison with fuel cells, thermionic and thermoelectric convertors, and heat engines. The potential applications of TPV systems include: remote electricity supplies, transportation, co-generation, electric-grid independent appliances, and space, aerospace, and military power applications. The range of bandgaps for achieving high conversion efficiencies using low temperature (1000-2000 K) black-body or selective radiators is in the 0.5-0.75 eV range. Present high efficiency convertors are based on single crystalline materials such as In1-xGaxAs, GaSb, and Ga1-xInxSb. Several polycrystalline thin films such as Hg1-xCdxTe, Sn1-xCd2xTe2, and Pb1-xCdxTe, etc., have great potential for economic large-scale applications. A small fraction of the high concentration of charge carriers generated at high fluences effectively saturates the large density of defects in polycrystalline thin films. Photovoltaic conversion efficiencies of polycrystalline thin films and PV solar cells are comparable to single crystalline Si solar cells, e.g., 17.1% for CuIn1-xGaxSe2 and 15.8% for CdTe. The best recombination-state density Nt is in the range of 10-15-10-16 cm-3 acceptable for TPV applications. Higher efficiencies may be achieved because of the higher fluences, possibility of bandgap tailoring, and use of selective emitters such as rare earth oxides (erbia, holmia, yttria) and rare earth-yttrium aluminium garnets. As compared to higher bandgap semiconductors such as CdTe, it is easier to dope the lower bandgap semiconductors. TPV cell development can benefit from the more mature PV solar cell and opto-electronic (infrared detectors, lasers, and optical communications) technologies. Low bandgaps and larger fluences employed in TPV cells result in very high current densities which make it difficult to collect the current effectively. Techniques for laser and mechanical scribing, integral interconnection, and multi-junction tandem structures which have been fairly well developed for thin-film PV solar cells could be further refined for enhancing the voltages from TPV modules. Thin-film TPV cells may be deposited on metals or back-surface reflectors. Spectral control elements such as indium-tin oxide or tin oxide may be deposited directly on the TPV convertor. It would be possible to reduce the cost of TPV technologies based on single-crystal materials being developed at present to the range of US 2-5 per watt so as to be competitive in small to medium size commercial applications. However, a further cost reduction to the range of US ¢ 35- 1 per watt to reach the more competitive large-scale residential, consumer, and hybrid-electric car markets would be possible only with the polycrystalline-thin film TPV cells.

  8. Photoelectrode thin film of dye-sensitized solar cell fabricated by anodizing method and spin coating and electrochemical impedance properties of DSSC

    International Nuclear Information System (INIS)

    The paper studies the photoelectrode thin film of dye-sensitized solar cell (DSSC) fabricated by anodizing method, explores the structure and properties of the fabricated photoelectrode thin film, measures the photoelectric conversion efficiency of DSSC, and finds the electrochemical impedance properties of DSSCs assembled by photoelectrode thin films in different thicknesses. Besides, in order to increase the specific surface area of nanotubes, this paper deposits TiO2 nanoparticles (TNP) on the surface of titanium oxide nanotube (TNT). As shown in experimental results, the photoelectric conversion efficiency of the DSSC fabricated by the study rises to 6.5% from the original 5.43% without TnB treatment, with an increase of photoelectric conversion efficiency by 19.7%. In addition, when the photoelectrode thin film is fabricated with mixture of TNTs and TNP in an optimal proportion of 2:8 and the photoelectrode thin film thickness is 15.5 ?m, the photoelectric conversion efficiency can reach 7.4%, with an increase of 36.7% from the original photoelectric conversion efficiency at 5.43%. Besides, as found in the results of electrochemical impedance analysis, the DSSC with photoelectrode thin film thickness at 15.5 ?m has the lowest charge-conduction resistance (Rk) value 9.276 ? of recombined electron and conduction resistance (Rw) value 3.25 ? of electrons in TiO2.

  9. Photoelectrode thin film of dye-sensitized solar cell fabricated by anodizing method and spin coating and electrochemical impedance properties of DSSC

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Ho, E-mail: f10381@ntut.edu.tw [Graduate Institute of Manufacturing Technology, National Taipei University of Technology, Taipei 10608, Taiwan (China); Chen, Chih-Hao [Department of Thoracic Surgery, Mackay Memorial Hospital, Taipei 10419, Taiwan (China); Graduate Institute of Mechanical and Electrical Engineering, National Taipei University of Technology, Taipei 10608, Taiwan (China); Kao, Mu-Jung [Department of Vehicle Engineering, National Taipei University of Technology, Taipei 10608, Taiwan (China); Chien, Shu-Hua [Institute of Chemistry, Academia Sinica, Taipei 115, Taiwan (China); Chou, Cheng-Yi [Graduate Institute of Manufacturing Technology, National Taipei University of Technology, Taipei 10608, Taiwan (China)

    2013-06-15

    The paper studies the photoelectrode thin film of dye-sensitized solar cell (DSSC) fabricated by anodizing method, explores the structure and properties of the fabricated photoelectrode thin film, measures the photoelectric conversion efficiency of DSSC, and finds the electrochemical impedance properties of DSSCs assembled by photoelectrode thin films in different thicknesses. Besides, in order to increase the specific surface area of nanotubes, this paper deposits TiO{sub 2} nanoparticles (TNP) on the surface of titanium oxide nanotube (TNT). As shown in experimental results, the photoelectric conversion efficiency of the DSSC fabricated by the study rises to 6.5% from the original 5.43% without TnB treatment, with an increase of photoelectric conversion efficiency by 19.7%. In addition, when the photoelectrode thin film is fabricated with mixture of TNTs and TNP in an optimal proportion of 2:8 and the photoelectrode thin film thickness is 15.5 ?m, the photoelectric conversion efficiency can reach 7.4%, with an increase of 36.7% from the original photoelectric conversion efficiency at 5.43%. Besides, as found in the results of electrochemical impedance analysis, the DSSC with photoelectrode thin film thickness at 15.5 ?m has the lowest charge-conduction resistance (R{sub k}) value 9.276 ? of recombined electron and conduction resistance (R{sub w}) value 3.25 ? of electrons in TiO{sub 2}.

  10. Photoelectrode thin film of dye-sensitized solar cell fabricated by anodizing method and spin coating and electrochemical impedance properties of DSSC

    Science.gov (United States)

    Chang, Ho; Chen, Chih-Hao; Kao, Mu-Jung; Chien, Shu-Hua; Chou, Cheng-Yi

    2013-06-01

    The paper studies the photoelectrode thin film of dye-sensitized solar cell (DSSC) fabricated by anodizing method, explores the structure and properties of the fabricated photoelectrode thin film, measures the photoelectric conversion efficiency of DSSC, and finds the electrochemical impedance properties of DSSCs assembled by photoelectrode thin films in different thicknesses. Besides, in order to increase the specific surface area of nanotubes, this paper deposits TiO2 nanoparticles (TNP) on the surface of titanium oxide nanotube (TNT). As shown in experimental results, the photoelectric conversion efficiency of the DSSC fabricated by the study rises to 6.5% from the original 5.43% without TnB treatment, with an increase of photoelectric conversion efficiency by 19.7%. In addition, when the photoelectrode thin film is fabricated with mixture of TNTs and TNP in an optimal proportion of 2:8 and the photoelectrode thin film thickness is 15.5 ?m, the photoelectric conversion efficiency can reach 7.4%, with an increase of 36.7% from the original photoelectric conversion efficiency at 5.43%. Besides, as found in the results of electrochemical impedance analysis, the DSSC with photoelectrode thin film thickness at 15.5 ?m has the lowest charge-conduction resistance (Rk) value 9.276 ? of recombined electron and conduction resistance (Rw) value 3.25 ? of electrons in TiO2.

  11. Optimization of processing and modeling issues for thin film solar cell devices: Final report, February 3, 1997--September 1, 1998

    Energy Technology Data Exchange (ETDEWEB)

    Birkmire, R. W.; Phillips, J. E.; Shafarman, W. N.; Hegedus, S. S.; McCandless, B. E.

    2000-02-28

    This final report describes results achieved under a 20-month NREL subcontract to develop and understand thin-film solar cell technology associated to CuInSe{sub 2} and related alloys, a-Si and its alloys, and CdTe. Modules based on all these thin films are promising candidates to meet DOE's long-range efficiency, reliability and manufacturing cost goals. The critical issues being addressed under this program are intended to provide the science and engineering basis for the development of viable commercial processes and to improve module performance. The generic research issues addressed are: (1) quantitative analysis of processing steps to provide information for efficient commercial-scale equipment design and operation; (2) device characterization relating the device performance to materials properties and process conditions; (3) development of alloy materials with different bandgaps to allow improved device structures for stability and compatibility with module design; (4) development and improved window/heterojunction layers and contacts to improve device performance and reliability; and (5) evaluation of cell stability with respect to device structure and module encapsulation.

  12. Determination of optical and mechanical properties of Nb{sub 2}O{sub 5} thin films for solar cells application

    Energy Technology Data Exchange (ETDEWEB)

    Mazur, M. [Faculty of Microsystem Electronics and Photonics, Wroclaw University of Technology, Janiszewskiego 11/17, Wroc?aw (Poland); Szyma?ska, M., E-mail: magdalena.szymanska@its.waw.pl [Centre for Material Testing and Mechatronics, Motor Transport Institute, Jagiellonska 80, Warsaw (Poland); Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, Warsaw (Poland); Kaczmarek, D. [Faculty of Microsystem Electronics and Photonics, Wroclaw University of Technology, Janiszewskiego 11/17, Wroc?aw (Poland); Kalisz, M. [Centre for Material Testing and Mechatronics, Motor Transport Institute, Jagiellonska 80, Warsaw (Poland); Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, Warsaw (Poland); Wojcieszak, D.; Domaradzki, J. [Faculty of Microsystem Electronics and Photonics, Wroclaw University of Technology, Janiszewskiego 11/17, Wroc?aw (Poland); Placido, F. [University of the West of Scotland, High Street, Paisley, PA1 2BE, and SUPA, Scottish Universities Physics Alliance (United Kingdom)

    2014-05-01

    Highlights: • Niobium pentoxide films were prepared by microwave assisted magnetron sputtering. • Optical and mechanical properties of Nb{sub 2}O{sub 5} thin films were investigated. • The surface of thin films was homogenous, crack free and exhibited low RMS roughness. • Prepared Nb{sub 2}O{sub 5} coatings were well transparent from ca., 350 nm. • Hardness of deposited coatings was ca., 7 GPa. - Abstract: In this paper investigation results of niobium pentoxide thin films deposited by microwave assisted reactive magnetron sputtering process were described. Surface of prepared coatings was examined with the aid of atomic force microscope (AFM) operating in the contact-mode and in ultra high vacuum conditions. The surface of thin films was homogenous, crack free and exhibit low root mean square (RMS) roughness of about 0.34 nm. X-ray photoelectron spectroscopy (XPS) studies were performed to determine the chemical states of the niobium at the surface of thin films. Contact angle and surface free energy were additionally investigated to examine the surface properties of the deposited coatings. Optical properties of the Nb{sub 2}O{sub 5} thin films showed, that prepared coatings were well transparent from 350 nm to longer wavelength range. Based on transmission and reflection measurements the values of refractive index and extinction coefficient were determined. The antireflective coating based on Nb{sub 2}O{sub 5} thin films for solar cells application was proposed. The hardness and Young's modulus measurements were performed by the nanoindentation technique. These investigations revealed that the hardness of the deposited coatings was ca., 7 GPa. Also scratch tests were applied, which have shown that the Nb{sub 2}O{sub 5} thin films were scratch resistant.

  13. 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 an edge seal technology

  14. New diarylmethanofullerene derivatives and their properties for organic thin-film solar cells

    Directory of Open Access Journals (Sweden)

    Daisuke Sukeguchi

    2009-02-01

    Full Text Available A number of diarylmethanofullerene derivatives were synthesized. The cyclopropane ring of the derivatives has two aryl groups substituted with electron-withdrawing and -donating groups, the latter with long alkyl chains to improve solubility in organic solvents, an important property in processing cells. First reduction potentials of most derivatives were less negative than that of [6,6]-phenyl-C61-butyric acid methyl ester (PCBM, which is possibly ascribed to their electron-withdrawing nature. Organic thin-film photovoltaic cells fabricated with poly(3-hexylthiophene (P3HT as the electron-donor and diarylmethanofullerene derivatives as the electron-acceptor material were examined. The {(methoxycarbonylphenyl[bis(octyloxyphenyl]methano}fullerene showed power conversion efficiency as high as PCBM, but had higher solubility in a variety of organic solvents than PCBM. The Voc value was higher than that of PCBM, which is derived from the electron-donating (octyloxyphenyl group, possibly raising the LUMO level. Photovoltaic effects of the devices fabricated with the derivatives having some electron-withdrawing groups were also examined.

  15. Low temperature growth and properties of Cu-In-Te based thin films for narrow bandgap solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Mise, Takahiro, E-mail: mise@ee.aoyama.ac.j [Department of Electrical Engineering and Electronics, Aoyama Gakuin University, 5-10-1 Fuchinobe, Sagamihara, Kanagawa, 229-8558 (Japan); Nakada, Tokio [Department of Electrical Engineering and Electronics, Aoyama Gakuin University, 5-10-1 Fuchinobe, Sagamihara, Kanagawa, 229-8558 (Japan)

    2010-07-30

    Cu-In-Te based thin films were grown onto soda-lime glass (SLG) substrates at 200 {sup o}C by co-evaporation using a molecular beam epitaxy system. The microstructural properties were examined by means of scanning electron microscopy, X-ray diffraction and Raman scattering. The crystalline quality of Cu-In-Te based thin films with high Cu/In ratios is superior to that of films with low Cu/In ratios. The films with Cu/In ratios of 0.69 {+-} 0.04 exhibited a single chalcopyrite phase with random orientation, whereas a defect chalcopyrite phase with a preferred (112) orientation was obtained for thin films with Cu/In ratios of 0.26 {+-} 0.02. However, the films with high Cu/In ratios of 0.69 {+-} 0.04 showed nearly constant low resistivity ({approx} 10{sup -2} {Omega} cm) at temperatures from 80 to 400 K due to high hole concentration (> 10{sup 19} cm{sup -3}), resulting in semi-metallic behavior. The hole conduction mechanism of the film (Cu/In atomic ratios = 0.26 {+-} 0.02) with semi-conductive properties was found to be variable-range-hopping of the Mott type in the wide range of 80-300 K. The optical bandgaps of Cu-In-Te based thin films are determined to be 0.93-1.02 eV at 300 K from transmission and reflection measurements. A solar cell with a ZnO/CdS/CuIn{sub 3}Te{sub 5}/Mo/SLG structure showed a total area (0.50 cm{sup 2}) efficiency of 5.1% under AM1.5 illumination (100 mW/cm{sup 2}) after light soaking. The conduction band offset at the CdS/CuIn{sub 3}Te{sub 5} interface was estimated to be - 0.14 eV from X-ray photoelectron spectroscopy analysis.

  16. Enhanced electrical properties at boundaries including twin boundaries of polycrystalline CdTe thin-film solar cells.

    Science.gov (United States)

    Li, H; Liu, X X; Lin, Y S; Yang, B; Du, Z M

    2015-05-01

    The effect of grain boundaries (GBs), in particular twin boundaries (TBs), on CdTe polycrystalline thin films is studied by conductive atomic force microscopy (C-AFM), electron-beam-induced current (EBIC), scanning Kelvin probe microscopy (SKPM), electron backscatter diffraction (EBSD), and scanning transmission electron microscopy (STEM). Four types of CdTe grains with various densities of {111} ?3 twin boundaries (TBs) are found in Cl-treated CdTe polycrystalline thin films: (1) grains having multiple {111} ?3 TBs with a low angle to the film surface; (2) grains having multiple {111} ?3 TBs parallel to the film surfaces; (3) small grains on a scale of not more than 500 nm, composed of Cd, Cl, Te, and O; and (4) CdTe grains with not more than two {111} ?3 TBs. Grain boundaries (including TBs) exhibit enhanced current transport phenomena. However, the {111} ?3 TB is much more beneficial to micro-current transport. The enhanced current transport can be explained by the lower electron potential at GBs (including TBs) than the grain interiors (GIs). Our results open new opportunities for enhancing solar cell performances by controlling the grain boundaries, and in particular TBs. PMID:25857742

  17. Spray-on PEDOT:PSS and P3HT:PCBM Thin Films for Polymer Solar Cells

    Directory of Open Access Journals (Sweden)

    Morteza Eslamian

    2014-01-01

    Full Text Available PEDOT:PSS electron-blocking layer, and PEDOT:PSS + P3HT:PCBM stacked layers are fabricated by ultrasonic atomization and characterized by scanning electron microscopy (SEM and optical profilometry. The measured thicknesses based on SEM and optical profilometry are quite different, indicating the incapability of measurement techniques for non-uniform thin films. The thickness measurements are compared against theoretical estimations and a qualitative agreement is observed. Results indicate that using a multiple pass fabrication strategy results in a more uniform thin film. It was also found that the film characteristics are a strong function of solution concentration and spraying passes, and a weak function of substrate speed. Film thickness increases with solution concentration but despite the prediction of theory, the increase is not linear, indicating a change in the film porosity and density, which can affect physical and opto-electrical properties. Overall, while spray coating is a viable fabrication process for a wide range of solar cells, film characteristics can be easily altered by a change in process parameters.

  18. Effect of fluorine plasma treatment with chemically reduced graphene oxide thin films as hole transport layer in organic solar cells

    International Nuclear Information System (INIS)

    The inorganic materials such as V2O5, MoO3 and WO3 were investigated to replace PEDOT:PSS as hole transport layer (HTL) in organic electronic devices such as organic solar cells (OSCs) and organic lighting emission diodes. However, these methods require vacuum techniques that are long time process and complex. Here, we report about plasma treatment with SF6 and CF4 using reactive ion etching on reduced graphene oxide (rGO) thin films that are obtained using an eco-friendly method with vitamin C. The plasma treated rGO thin films have dipoles since they consist of covalent bonds with fluorine on the surface of rGO. This means it is possible to increase the electrostatic potential energy than bare rGO. Increased potential energy on the surface of rGO films is worth applying organic electronic devices as HTL such as OSCs. Consequently, the power conversion efficiency of OSCs increased more than the rGO films without plasma treatment.

  19. Effect of fluorine plasma treatment with chemically reduced graphene oxide thin films as hole transport layer in organic solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Youn-Yeol; Kang, Byung Hyun; Lee, Yang Doo; Lee, Sang Bin; Ju, Byeong-Kwon, E-mail: bkju@korea.ac.kr

    2013-12-15

    The inorganic materials such as V{sub 2}O{sub 5}, MoO{sub 3} and WO{sub 3} were investigated to replace PEDOT:PSS as hole transport layer (HTL) in organic electronic devices such as organic solar cells (OSCs) and organic lighting emission diodes. However, these methods require vacuum techniques that are long time process and complex. Here, we report about plasma treatment with SF{sub 6} and CF{sub 4} using reactive ion etching on reduced graphene oxide (rGO) thin films that are obtained using an eco-friendly method with vitamin C. The plasma treated rGO thin films have dipoles since they consist of covalent bonds with fluorine on the surface of rGO. This means it is possible to increase the electrostatic potential energy than bare rGO. Increased potential energy on the surface of rGO films is worth applying organic electronic devices as HTL such as OSCs. Consequently, the power conversion efficiency of OSCs increased more than the rGO films without plasma treatment.

  20. Improving low pressure chemical vapor deposited zinc oxide contacts for thin film silicon solar cells by using rough glass substrates

    International Nuclear Information System (INIS)

    Compared to zinc oxide grown (ZnO) on flat glass, rough etched glass substrates decrease the sheet resistance (Rsq) of zinc oxide layers grown on it. We explain this Rsq reduction from a higher thickness and an improved electron mobility for ZnO layers deposited on rough etched glass substrates. When using this etched glass substrate, we also obtain a large variety of surface texture by changing the thickness of the ZnO layer grown on it. This new combination of etched glass and ZnO layer shows improved light trapping potential compared to ZnO films grown on flat glass. With this new approach, Micromorph thin film silicon tandem solar cells with high total current densities (sum of the top and bottom cell current density) of up to 26.8 mA cm?2 were fabricated.

  1. Plasmonic organic thin-film solar cell: light trapping by using conformal vs. non-conformal relief gratings

    Science.gov (United States)

    Keshmiri, Hamid; Dostlek, Jakub

    2015-05-01

    Theoretical study of light management in thin film organic photovoltaic cell that utilizes diffraction coupling to guided waves is presented. As a model system, a regular solar cell geometry with P3HT:PCBM active layer, transparent ITO electrode and Al backside electrode is used. The paper discusses enhancement of absorption of incident photons selectively in the active layer by the interplay of surface plasmon polariton and optical waveguide waves, the effect on the profile of their field and damping that affects the spatial distribution of dissipated light energy in the layer structure. The model shows that for optimized grating period and modulation depth the number of absorbed photons in the active layer can be increased by 24 per cent. The comparison of the geometry with conformal and non-conformally corrugated layers reveals that the conformal structure outperforms the non-conformal in the enhancing of photon absorption in the wavelength range of 350-800 nm.

  2. Cadmium sulfide nanowires for the window semiconductor layer in thin film CdS-CdTe solar cells

    International Nuclear Information System (INIS)

    Thin film CdS/CdTe heterojunction device is a leading technology for the solar cells of the next generation. We report on two novel device configurations for these cells where the traditional CdS window layer is replaced by nanowires (NW) of CdS, embedded in an aluminum oxide matrix or free-standing. An estimated 26.8% improvement in power conversion efficiency over the traditional device structure is expected, primarily because of the enhanced spectral transmission of sunlight through the NW-CdS layer and a reduction in the junction area/optical area ratio. In initial experiments, nanostructured devices of the two designs were fabricated and a power conversion efficiency value of 6.5% was achieved.

  3. Physical properties of sublimated zinc telluride thin films for solar cell applications

    International Nuclear Information System (INIS)

    Zinc telluride (ZnTe) thin films were fabricated by using closed space sublimation (CSS) technique on glass substrate under vacuum. Pre-fabricated ZnTe thin films were doped with silver (Ag) by ion exchange method. X-ray diffraction showed the preferred orientation (111) of ZnTe thin film with polycrystalline behavior. Scanning electron microscope images were taken to estimate the grain boundaries; energy dispersive X-ray results confirmed the Ag composition in doped-ZnTe samples. Electrical measurements were performed to determine the resistivity, mobility and carrier concentrations of un-doped thin films and Ag-doped samples. The electrical resistivity was of the order of 106 ?-cm before doping. Ag-doped ZnTe samples exhibits low resistivity of the order of 103 ?-cm along with a change in the carrier concentrations and mobility as well at room temperature. The angle resolved optical transmission data, taken by spectrophotometer, was used to find the optical properties before and after Ag doping. Energy band gap showed decreasing trend with increasing Ag doping time. - Highlights: • Zinc telluride thin films were grown by closed space sublimation technique. • Ag was doped, by ion exchange process. • Physical properties were investigated before and after doping

  4. Physical properties of sublimated zinc telluride thin films for solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Shah, Nazar Abbas, E-mail: nazar_abbas@comsats.edu.pk; Mahmood, Waqar

    2013-10-01

    Zinc telluride (ZnTe) thin films were fabricated by using closed space sublimation (CSS) technique on glass substrate under vacuum. Pre-fabricated ZnTe thin films were doped with silver (Ag) by ion exchange method. X-ray diffraction showed the preferred orientation (111) of ZnTe thin film with polycrystalline behavior. Scanning electron microscope images were taken to estimate the grain boundaries; energy dispersive X-ray results confirmed the Ag composition in doped-ZnTe samples. Electrical measurements were performed to determine the resistivity, mobility and carrier concentrations of un-doped thin films and Ag-doped samples. The electrical resistivity was of the order of 10{sup 6} ?-cm before doping. Ag-doped ZnTe samples exhibits low resistivity of the order of 10{sup 3} ?-cm along with a change in the carrier concentrations and mobility as well at room temperature. The angle resolved optical transmission data, taken by spectrophotometer, was used to find the optical properties before and after Ag doping. Energy band gap showed decreasing trend with increasing Ag doping time. - Highlights: • Zinc telluride thin films were grown by closed space sublimation technique. • Ag was doped, by ion exchange process. • Physical properties were investigated before and after doping.

  5. Highly transparent front electrodes with metal fingers for p-i-n thin-film silicon solar cells

    Science.gov (United States)

    Moulin, Etienne; Müller, Thomas Christian Mathias; Warzechac, Marek; Hoffmann, Andre; Paetzold, Ulrich Wilhelm; Aeberhard, Urs

    2015-03-01

    The optical and electrical properties of transparent conductive oxides (TCOs), traditionally used in thin-film silicon (TF-Si) solar cells as front-electrode materials, are interlinked, such that an increase in TCO transparency is generally achieved at the cost of reduced lateral conductance. Combining a highly transparent TCO front electrode of moderate conductance with metal fingers to support charge collection is a well-established technique in wafer-based technologies or for TF-Si solar cells in the substrate (n-i-p) configuration. Here, we extend this concept to TF-Si solar cells in the superstrate (p-i-n) configuration. The metal fingers are used in conjunction with a millimeter-scale textured foil, attached to the glass superstrate, which provides an antireflective and retroreflective effect; the latter effect mitigates the shadowing losses induced by the metal fingers. As a result, a substantial increase in power conversion efficiency, from 8.7% to 9.1%, is achieved for 1-?m-thick microcrystalline silicon solar cells deposited on a highly transparent thermally treated aluminum-doped zinc oxide layer combined with silver fingers, compared to cells deposited on a state-of-the-art zinc oxide layer.

  6. Highly transparent front electrodes with metal fingers for p-i-n thin-film silicon solar cells

    Directory of Open Access Journals (Sweden)

    Moulin Etienne

    2015-01-01

    Full Text Available The optical and electrical properties of transparent conductive oxides (TCOs, traditionally used in thin-film silicon (TF-Si solar cells as front-electrode materials, are interlinked, such that an increase in TCO transparency is generally achieved at the cost of reduced lateral conductance. Combining a highly transparent TCO front electrode of moderate conductance with metal fingers to support charge collection is a well-established technique in wafer-based technologies or for TF-Si solar cells in the substrate (n-i-p configuration. Here, we extend this concept to TF-Si solar cells in the superstrate (p-i-n configuration. The metal fingers are used in conjunction with a millimeter-scale textured foil, attached to the glass superstrate, which provides an antireflective and retroreflective effect; the latter effect mitigates the shadowing losses induced by the metal fingers. As a result, a substantial increase in power conversion efficiency, from 8.7% to 9.1%, is achieved for 1-?m-thick microcrystalline silicon solar cells deposited on a highly transparent thermally treated aluminum-doped zinc oxide layer combined with silver fingers, compared to cells deposited on a state-of-the-art zinc oxide layer.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ang, P. C.; Ibrahim, K.; Pakhuruddin, M. Z. [Nano-Optoelectronics Research and Technology Laboratory, School of Physics, Universiti Sains Malaysia, Minden 11800 Penang (Malaysia)

    2015-04-24

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

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

    International Nuclear Information System (INIS)

    One way to realize low-cost thin film silicon (Si) solar cells fabrication is by depositing the films with high-deposition rate and manufacturing-compatible electron beam (e-beam) evaporation onto inexpensive foreign substrates such as glass or plastic. Most of the ongoing research is reported on e-beam evaporation of Si films on glass substrates to make polycrystalline solar cells but works combining both e-beam evaporation and plastic substrates are still scarce in the literature. This paper studies electrical properties and surface morphology of 1 µm electron beam evaporated Al-doped p-type silicon thin films on textured polyethylene terephthalate (PET) substrate for application as an absorber layer in solar cells. In this work, Si thin films with different doping concentrations (including an undoped reference) are prepared by e-beam evaporation. Energy dispersion X-ray (EDX) showed that the Si films are uniformly doped by Al dopant atoms. With increased Al/Si ratio, doping concentration increased while both resistivity and carrier mobility of the films showed opposite relationships. Root mean square (RMS) surface roughness increased. Overall, the Al-doped Si film with Al/Si ratio of 2% (doping concentration = 1.57×1016 atoms/cm3) has been found to provide the optimum properties of a p-type absorber layer for fabrication of thin film Si solar cells on PET substrate

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

    Science.gov (United States)

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

    2015-04-01

    One way to realize low-cost thin film silicon (Si) solar cells fabrication is by depositing the films with high-deposition rate and manufacturing-compatible electron beam (e-beam) evaporation onto inexpensive foreign substrates such as glass or plastic. Most of the ongoing research is reported on e-beam evaporation of Si films on glass substrates to make polycrystalline solar cells but works combining both e-beam evaporation and plastic substrates are still scarce in the literature. This paper studies electrical properties and surface morphology of 1 µm electron beam evaporated Al-doped p-type silicon thin films on textured polyethylene terephthalate (PET) substrate for application as an absorber layer in solar cells. In this work, Si thin films with different doping concentrations (including an undoped reference) are prepared by e-beam evaporation. Energy dispersion X-ray (EDX) showed that the Si films are uniformly doped by Al dopant atoms. With increased Al/Si ratio, doping concentration increased while both resistivity and carrier mobility of the films showed opposite relationships. Root mean square (RMS) surface roughness increased. Overall, the Al-doped Si film with Al/Si ratio of 2% (doping concentration = 1.57×1016 atoms/cm3) has been found to provide the optimum properties of a p-type absorber layer for fabrication of thin film Si solar cells on PET substrate.

  10. Growth, etching, and stability of sputtered ZnO:Al for thin-film silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Owen, Jorj Ian

    2011-07-01

    Aluminum-doped zinc oxide (ZnO:Al) can fulfill many requirements in thin-film solar cells, acting as (1) a transparent contact through which the incident light is transmitted, (2) part of the back reflector, and (3) a source of light scattering. Magnetron sputtered ZnO:Al thin-films are highly transparent, conductive, and are typically texturized by post-deposition etching in a dilute hydrochloric acid (HCl) solution to achieve light scattering. The ZnO:Al thin-film electronic and optical properties, as well as the surface texture after etching, depend on the deposition conditions and the post-deposition treatments. Despite having been used in thin-film solar cells for more than a decade, many aspects regarding the growth, effects of heat treatments, environmental stability, and etching of sputtered ZnO:Al are not fully understood. This work endeavors to further the understanding of ZnO:Al for the purpose improving silicon thin-film solar cell efficiency and reducing ZnO:Al production costs. With regard to the growth of ZnO:Al, the influence of various deposition conditions on the resultant electrical and structural properties and their evolution with film thickness were studied. The surface electrical properties extracted from a multilayer model show that while carrier concentration of the surface layer saturates already at film thickness of 100 nm, the surface mobility continues to increases with film thickness, and it is concluded that electronic transport across grain boundaries limits mobility in ZnO:Al thin films. ZnO:Al deposited onto a previously etched ZnO:Al surface grows epitaxially, preserving both the original orientation and grain structure. Further, it is determined that a typical ZnO:Al used in thin-film silicon solar cells grows Zn-terminated on glass substrates. Concerning the affects of heat treatments and stability, it is demonstrated that a layer of amorphous silicon can protect ZnO:Al from degradation during annealing, and the mobility of ZnO:Al films can be increased up to 76 cm{sup 2}/Vs by annealing at high temperatures. Further, it is observed that this annealing process does not affect the morphology of the film and increases the total transmission in the solar cell relevant portion of the spectrum. Accelerated aging in a damp-heat is shown to affect the mobility primarily, and is thus likely related to poor transport across grain boundaries. Using deuterium as an isotopic marker, it is observed that the deuterium uptake was fairly linear with time and penetrated the whole film within 24 hours. Additionally, the deuterium is quickly replaced by hydrogen upon damp-heat treatment in water. It is concluded that the electrical degradation is related to the penetration of water via grain boundaries, and that the bulk of the reactions causing this degradation are fairly weak, such as the formation of zinc hydroxide. Additionally, the annealed high-mobility ZnO:Al films prove to be very stable in the damp-heat environment, exhibiting electron mobilities above 70 cm{sup 2}/Vs after 1000 hours of exposure. The initial points of attack during HCl etching of ZnO:Al, and the long-term etch evolution are shown to be related to certain grain boundaries built into the film during growth. The density of craters from an HCl etch is controllable by altering the temperature and concentration of the etching solution. It is further demonstrated that most acids exhibit etching behavior similar to that of HCl. Hydrofluoric acid (HF), however, exhibits unique etching characteristics with higher crater densities and sharper features. The crater density and shape are also shown to be controllable by etching in various concentrations of HF and in various mixtures of HF and HCl. Additional etching experiments are made to develop a polycrystalline ZnO:Al etching model. It is shown that basic and acidic solutions attack the same points on a polycrystalline ZnO:Al sample. The dependence of crater density on the acid concentration, temperature, and type holds true for single crystal ZnO. Planar and cross-sectional transmissio

  11. Aluminum induced crystallization of sputtered hydrogenated amorphous silicon for economically viable thin film silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Hossain, Maruf [University of Arkansas; Abu-Safe, Husam H [University of Arkansas; Naseem, Hameed [University of Arkansas; Brown, Walter D [University of Arkansas; Meyer III, Harry M [ORNL

    2005-01-01

    Poly-crystalline silicon (poly-Si) thin films have been prepared by aluminum induced crystallization (AiC) technique. Hydrogenated amorphous silicon (a-Si:H) thin films were prepared by sputtering a silicon target in hydrogen and argon ambient. It was observed that deposition rates increased more than two folds with the introduction of the hydrogen in the deposition chamber. The a-Si:H thin films were coated with a thin layer of sputtered aluminum (AI). X-ray diffraction (XRD) confirmed that the crystallization commenced at as low as 225 C. The depth profile of the annealed samples, obtained by scanning Auger microscopy (SAM), did not show any layer exchange below 300 C. The SAM analysis showed clear layer exchange in the higher temperature ( >350 C) region.

  12. Na-Doped Mo Target Sputtering for CIGS Thin Film Solar Cells on Stainless Steel Substrate

    OpenAIRE

    Lin, Y. C.; Shi, Z.H.; C. H. Shen; Chen, Y. L.

    2013-01-01

    This study deposited Cu(In,Ga)Se2(CIGS) thin films on Mo/SiOx/SS431 substrates using magnetron sputtering. Our objectives were to introduce a Mo-5%Na target as a source of incorporate Na to the chalcopyrite structure and investigate its influence on the crystallinity of CIGS thin films. Experimental results demonstrate that adding Na in this manner can enhance the distribution of Na on the surface as well as the depth profile. When the thickness ratio of Mo-5%Na: Mo was 2.8%, the atomic ratio...

  13. Cu{sub 2}ZnSnS{sub 4} thin film solar cells prepared by non-vacuum processing

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Kunihiko; Oonuki, Masatoshi; Moritake, Noriko; Uchiki, Hisao [Department of Electrical Engineering, Nagaoka University of Technology, 1603-1 Kamitomioka-machi, Nagaoka, Niigata 940-2188 (Japan)

    2009-05-15

    Cu{sub 2}ZnSnS{sub 4} (CZTS)-based solar cell devices were prepared entirely by non-vacuum deposition techniques on soda lime glass (SLG) substrates. The ZnO:Al window, CdS buffer and CZTS absorber layers of the Al/ZnO:Al/CdS/CZTS/Mo/SLG solar cell structure were deposited by sol-gel method, chemical bath deposition method and sol-gel sulfurizing method, respectively. The best solar cell sample showed an open-circuit voltage of 390 mV, a short-circuit current density of 7.8mA/cm{sup 2}, a fill factor of 0.33 and an efficiency of 1.01% under irradiation of AM 1.5 and 100mW/cm{sup 2}. This is the first report on CZTS thin film solar cells in which all the semiconductor layers were prepared under non-vacuum condition. (author)

  14. Properties Of A Qualified Space Solar Sheet With InGaP/GaAs Dual-Junction Thin Film Solar Cells

    Science.gov (United States)

    Imaizumi, Mitsuru; Shimazaki, Kazunori; Kobayashi, Yuki; Takahashi, Masato; Nakamura, Kazuyo; Takamoto, Tatsuya; Sata, Shin-ichiro; Ohshima, Takeshi

    2011-10-01

    JAXA's approach to realizing a high specific power solar paddle by utilizing thin-film III-V multi-junction solar cells is introduced. Thin-film cells laminated with thin and transparent sustaining materials have been named a "Space Solar Sheet (SSS)." Development of the first-generation SSS (SSS-1) was completed in 2010. Thin-film InGaP/GaAs dual-junction (TF2J) cells are used as solar cells in the SSS-1. The AM0 efficiency of the TF2J cells is ~25%. Two types of lamination structure for the active side are employed: one uses transparent films with UV coating, and the other has a conventional configuration using a coverglass. The specific power of the SSS-1 is 0.4-0.5 W/g. Characterization and environmental qualification tests have confirmed their space quality and life at more than 5 years in the LEO environment (the film type) and 10 years in the GEO environment (the coverglass type). The SSS-1 is now commercially available. The second- generation SSS (SSS-2) development started in 2010. The major improvement from the SSS-1 to the SSS-2 will be cell efficiency, achieved by adopting an inverted metamorphic InGaP/GaAs/InGaAs triple-junction solar cell: the target efficiency is 32% at BOL. The lamination technology will be also modified for the SSS-2 to improve specific power. The achievement of such a SSS will enable us to realize lightweight solar paddles with specific power of 150 W/kg or greater.

  15. Conducting glasses recovered from thin film transistor liquid crystal display wastes for dye-sensitized solar cell cathodes.

    Science.gov (United States)

    Chen, C-C; Chang, F-C; Peng, C Y; Wang, H Paul

    2015-12-01

    Transparent conductive glasses such as thin film transistor (TFT) array and colour filter glasses were recovered from the TFT-liquid crystal display panel wastes by dismantling and sonic cleaning. Noble metals (i.e. platinum (Pt)) and indium tin oxide (ITO) are generally used in the cathode of a dye-sensitized solar cell (DSSC). To reduce the DSSC cost, Pt was replaced with nano nickel-encapsulated carbon-shell (Ni@C) nanoparticles, which were prepared by carbonization of Ni(2+)-?-cyclodextrin at 673?K for 2?h. The recovered conductive glasses were used in the DSSC electrodes in the substitution of relatively expensive ITO. Interestingly, the efficiency of the DSSC having the Ni@C-coated cathode is as high as 2.54%. Moreover, the cost of the DSSC using the recovered materials can be reduced by at least 24%. PMID:25399759

  16. Electrical properties modulation of thin film solar cell using gold nanostructures at textured FTO/p-i-n interface

    Science.gov (United States)

    Gentile, A.; Cacciato, G.; Ruffino, F.; Reitano, R.; Scapellato, G.; Zimbone, M.; Grimaldi, M. G.; Lombardo, S.; Battaglia, A.; Gerardi, C.; Foti, M.

    2015-11-01

    We report about the modulation of the electrical properties of thin film solar cells due to the incorporation of size-selected Au nanostructures (NSs) at a textured FTO/p-i-n interface. By increasing the Au NSs size, the analyses of current-voltage characteristics show lower Schottky barrier heights and the gradual reduction of the open-circuit voltages (VOC). The optical measurements show higher parasitic absorption by larger Au NSs that reduces the amount of radiation transmitted by the transparent to absorber layer. This process decreases the number of photo-generated carriers and may explain the VOC reduction related to the devices with larger Au NSs at the interface. So, the correlation between materials properties and device performances was established.

  17. Photoluminescence of epitactical and polycrystalline CuInS2 layers for thin-film solar cells

    International Nuclear Information System (INIS)

    The present thesis deals with one- and polycrystalline CuInS2 absorber layers for thin-film solar cells and especially with their optical and structural characterization. By means of detailed temperature- and power-dependent photoluminescence measurements in epitactical and polycrystalline absorber layers different radiative transitions could be analyzed and identified. The spectra were dominated by broad luminescence bands of deep perturbing levels. The implantation of hydrogen at low energies led to a passivation of these perturbing levels. On the base of the optical studies on epitactical and polycrystalline absorber layers a new improved defect model for CuInS2 could be developed. The model contains two donor and two acceptor levels with following ionization energies: D-1=46 meV, D-2=87 meV, A-1=70 meV, and A-2=119 meV

  18. Fabrication of dye sensitized solar cell using Cr doped Cu-Zn-Se type chalcopyrite thin film

    Energy Technology Data Exchange (ETDEWEB)

    Joseph, D. Paul; Venkateswaran, C. [Materials Science Centre, Department of Nuclear Physics, University of Madras, Guindy Campus, Chennai-600 025 (India); Ganesan, S.; Suthanthiraraj, S. Austin; Maruthamuthu, P. [Department of Energy, University of Madras, Guindy Campus, Chennai 600 025 (India); Kovendhan, M. [Department of Physics, Presidency College, Chennai 600 005 (India)

    2011-09-15

    Chalcopyrites are a versatile class of semiconductors known for their potential in photovoltaic applications. Considering the well established CuInSe{sub 2} as a prototype system, a new compound of the chalcopyrite type, Cu{sub 1-x}Zn{sub 1-y}Se{sub 2-{delta}}, by replacing In with Zn, has been prepared (both undoped and 2% Cr doped) by the metallurgical method. Thin films have been deposited by the thermal evaporation technique using the stabilized polycrystalline compounds as charge. Structural, compositional, morphological, and optical properties of the films are analyzed and reported. Use of these films as electrodes in dye sensitized solar cell (DSSC) is demonstrated. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. XPS characterization of sensitized n-TiO2 thin films for dye-sensitized solar cell applications

    International Nuclear Information System (INIS)

    TiO2 thin films, employed in dye-sensitized solar cells, were prepared by the sol-gel method or directly by Degussa P25 oxide and their surfaces were characterized by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The effect of adsorption of the cis-[Ru(dcbH2)2(NCS)2] dye, N3, on the surface of films was investigated. From XPS spectra taken before and after argon-ion sputtering procedure, the surface composition of inner and outer layers of sensitized films was obtained and a preferential etching of Ru peak in relation to the Ti and N ones was identified. The photoelectrochemical parameters were also evaluated and rationalized in terms of the morphological characteristics of the films

  20. Tuning of undoped ZnO thin film via plasma enhanced atomic layer deposition and its application for an inverted polymer solar cell

    OpenAIRE

    Mi-jin Jin; Junhyeon Jo; Guru P. Neupane; Jeongyong Kim; Ki-Seok An; Jung-Woo Yoo

    2013-01-01

    We studied the tuning of structural and optical properties of ZnO thin film and its correlation to the efficiency of inverted solar cell using plasma-enhanced atomic layer deposition (PEALD). The sequential injection of DEZn and O2 plasma was employed for the plasma-enhanced atomic layer deposition of ZnO thin film. As the growth temperature of ZnO film was increased from 100?°C to 300?°C, the crystallinity of ZnO film was improved from amorphous to highly ordered (002) direction ploy-crystal...

  1. Transmission Electron Microscopy of the Textured Silver Back Reflector of a Thin Film Silicon Solar Cell: From Crystallography to Optical Absorption

    DEFF Research Database (Denmark)

    Duchamp, Martial; Söderström, K.; Jeangros, Q.; Boothroyd, Chris; Kovacs, A.; Kasama, Takeshi; Haug, F.-J; Ballif, C.; Dunin-Borkowski, Rafal E.; Ossenbrink, H.; Jager-Waldau, A.; Helm, P.

    2011-01-01

    The study of light trapping in amorphous, microcrystalline and micromorph thin-film Si solar cells is an important and active field of investigation. It has been demonstrated that the use of a rough Ag back-reflector lead to an increase of short circuit current but also to losses through the creation of surface plasmon polaritons. Here, we use transmission electron microscopy (TEM) techniques to study the grain structure of a Ag thin-film that was sputtered on top of 2-?m-thick rough ZnO layer -...

  2. Nanoimprint lithography of light trapping patterns in sol-gel coatings for thin film silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Heijna, M.; Loffler, J.; Van Aken, B.B.; Soppe, W.J. [ECN Solar Energy, Petten (Netherlands); Borg, H.; Peeters, P. [OM and T, Eindhoven (Netherlands)

    2008-04-15

    For thin-film silicon solar cells, light trapping schemes are of uppermost importance to harvest all available sunlight. Typically, randomly textured TCO front layers are used to scatter the light diffusively in p-i-n cells on glass. Here, we investigate methods to texture the back contact with both random and periodic textures, for use in n-i-p cells on opaque foil. We applied an electrically insulating SiOx-polymer coating on a stainless steel substrate, and textured this barrier layer by nanoimprint. On this barrier layer the back contact is deposited for further use in the solar cell stack. Replication of masters with various random and periodic patterns was tested, and, using scanning electron microscopy, replicas were found to compare well with the originals. Masters with U-grooves of various sub micrometer widths have been used to investigate the optimal dimensions of regular patterns for light trapping in the silicon layers. Angular reflection distributions were measured to evaluate the light scattering properties of both periodic and random patterns. Diffraction gratings show promising results in scattering the light to specific angles, enhancing the total internal reflection in the solar cell.

  3. Solution processed thin films of Nb-doped TiO2 nanoparticles as hole blocking layer for organic solar cells

    International Nuclear Information System (INIS)

    In this study, Nb-doped TiO2 nanoparticles were synthesized by sol–gel method with controlled doping ratios up to 6 mol%. Catalyzed by p-toluene sulfonic acid, alkoxide precursors of Ti and Ni were stabilized by acetylacetone ligand, and converted to the organically modified nanoparticles which were well dispersible in alcohols. Transmission electron microscopy and X-ray diffraction measurements revealed that TiO2 nanoparticle possesses anatase morphologies, and the doping ratios were confirmed by X-ray photoelectron spectroscopy. Uniform thin films of Nb-doped TiO2 were obtained by spin coating dilute alcohol dispersions of Nb-doped nanoparticles. Ellipsometric characterizations were carried out for the as-coated film and the sintered film as well to characterize the indices of refraction, and atomic force microscopy showed subnanometer-scale roughness of Nb-doped films. Owing to the improved roughness via doping, Nb-doped TiO2 thin films exhibited enhanced solar cell efficiencies when used as hole-blocking layer of organic hetero-junction solar cell. - Highlights: • We synthesize Nb-doped TiO2 nanoparticles by sol–gel method with up to 6 mol% doping. • We disperse nanoparticles in alcohols without aggregation. • Particle size decreases by high Nb doping. • Uniform thin films of Nb-doped TiO2 are obtained by spin coating. • Thin films used as hole blocking layer in organic solar cell enhance cell efficiency

  4. Efficient light incoupling into silicon thin-film solar cells by anti-reflecting MgO/high-compact-AZO with air-side textured glass

    International Nuclear Information System (INIS)

    Light incoupling effects have been enhanced at front interfaces of silicon (Si) thin-film solar cells. Firstly, a MgO thin film was introduced at glass substrate/Al-doped ZnO (AZO) interface for anti-reflection effect. We additionally found that the surface morphology of AZO films grown on MgO film after texture-etching is dependent on the compactness of AZO. For high-compact AZO films, the texture-etched MgO/AZO double layer exhibited significantly enhanced light-scattering capability. Secondly, we made textured surfaces at air/glass interface through simple plasma-etching without sacrificial layers or masks by optimizing the etching pressure. The additional air-side texture contributed to further improvement of total light scattering from the MgO/AZO-coated glass substrate. Fabricated microcrystalline Si thin-film solar cells employing the MgO coated glass with air-side surface texture showed decreased cell reflectance and increased quantum efficiency. The Jsc increased from 21.7 to 26.5 mA cm?2 and final efficiency of 9.49% was achieved. Based on our experimental results, the suggested structure, the MgO coating on glass substrate of which air-side surface is texture-etched, can offer a promising approach to improve the light incoupling and efficiency of Si thin-film solar cells. (paper)

  5. 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 ?m thickness gives maximum efficiency up to 24 % whereas same efficiency is achieved with the use of three bilayers grating based solar cell of 30 ?m 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 ?m cell thicknesses respectively. These presented designing efforts would be helpful to design and realize new generation of solar cells.

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

    International Nuclear Information System (INIS)

    The influence of various designing parameters were investigated and explored for high performance solar cells. Single layer grating based solar cell of 50 ?m thickness gives maximum efficiency up to 24 % whereas same efficiency is achieved with the use of three bilayers grating based solar cell of 30 ?m 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 ?m cell thicknesses respectively. These presented designing efforts would be helpful to design and realize new generation of solar cells

  7. Directly electrospinning growth of single crystal Cu2ZnSnS4 nanowires film for high performance thin film solar cell

    Science.gov (United States)

    Chen, Lin-Jer; Chuang, Yu-Ju

    2013-11-01

    Quaternary kesterite-type Cu2ZnSnS4 nanowires can be used as absorbing materials for thin film solar cells. The structural, morphological, compositional, and optical properties of the CZTS nanowires have been studied using X-ray diffraction (XRD), UV-vis spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and optical absorption techniques respectively. The Cu2ZnSnS4 nanowires, fabricated by electrospinning process and sintered at 600 °C in Argon atmosphere, the cells exhibits a power conversion efficiency of 6.18% under AM 1.5 solar irradiation in the thin film solar cells. This study suggests that the optimized Cu2ZnSnS4 composite nanowire is a promising absorbing material for high performance solar cells.

  8. The investigation of ZnO:Al2O3/metal composite back reflectors in amorphous silicon germanium thin film solar cells

    International Nuclear Information System (INIS)

    Different aluminum-doped ZnO (AZO)/metal composite thin films, including AZO/Ag/Al, AZO/Ag/nickel—chromium alloy (NiCr), and AZO/Ag/NiCr/Al, are utilized as the back reflectors of p—i—n amorphous silicon germanium thin film solar cells. NiCr is used as diffusion barrier layer between Ag and Al to prevent mutual diffusion, which increases the short circuit current density of solar cell. NiCr and NiCr/Al layers are used as protective layers of Ag layer against oxidation and sulfurization, the higher efficiency of solar cell is achieved. The experimental results show that the performance of a-SiGe solar cell with AZO/Ag/NiCr/Al back reflector is best. The initial conversion efficiency is achieved to be 8.05%

  9. Spray Deposited Thin Film Metal Oxide Based Heterojunction for Solar Cell Application

    OpenAIRE

    John Bosco Balaguru Rayappan; B.G. Jeyaprakash; Balamurugan, D.; R. Gayathri Devi; M.S. Inpasalini

    2012-01-01

    In the present study, thin film heterojunction based on n-CdO/p-NiO was fabricated on glass substrate by home built spray pyrolysis technique under optimized condition. Cadmium acetate dihydrate and Nickel chloride were used as precursors. Structural, surface morphology, optical and photovoltaic properties were analyzed and reported.

  10. Spray Deposited Thin Film Metal Oxide Based Heterojunction for Solar Cell Application

    Directory of Open Access Journals (Sweden)

    John Bosco Balaguru Rayappan

    2012-01-01

    Full Text Available In the present study, thin film heterojunction based on n-CdO/p-NiO was fabricated on glass substrate by home built spray pyrolysis technique under optimized condition. Cadmium acetate dihydrate and Nickel chloride were used as precursors. Structural, surface morphology, optical and photovoltaic properties were analyzed and reported.

  11. Nano-level characterization of silicon thin films and solar cells.

    Czech Academy of Sciences Publication Activity Database

    Fejfar, Antonín

    Tokyo : Ohmsha, 2013 - (Konagai, M.), s. 468-478 ISBN 978-4-274-21399-1 R&D Projects: GA MŠk(CZ) LM2011026 Grant ostatní: AV?R(CZ) M100101217 Institutional support: RVO:68378271 Keywords : silicon * thin film s * atomic force microscopy * photoresponse Subject RIV: BM - Solid Matter Physics ; Magnetism

  12. Thin film poly-Si solar cell with ``STAR structure`` on glass substrate fabricated at low temperature

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Kenji; Yoshimi, Masashi; Suzuki, Takayuki; Okamoto, Yoshifumi; Tawada, Yuko; Nakajima, Akihiko [Kaneka Corp., Kobe (Japan). Central Research Labs.

    1997-12-31

    The performances of thin film poly-Si solar cells with a thickness of less than 5 {micro}m on a glass substrate have been systematically investigated as a function of thickness. The cell of glass/back reflector/n-i-p poly-Si/ITO is well characterized by the structure of naturally surface texture and enhanced absorption with a back reflector (STAR), where the active i-layer was fabricated by plasma chemical vapor deposition (CVD) at low temperature. The cell with a thickness of 3.5 {micro}M and 2.5 {micro}m demonstrated an intrinsic efficiency of 9.8%, as independently confirmed by Japan Quality Assurance. The optical confinement effect explains the excellent spectral response at long wavelength for the cells through the PC1D analysis. The higher sensitivity at long-wavelength of the cell appeared in quantum efficiency curves is well correlated to the result of reflectance measurement. The open circuit voltage of 0.526 mV and the efficiency of 9.3% has been achieved for the cell with a thickness of 1.5 {micro}m, which was proved to be entirely stable with respect to the light-soaking. The stabilized efficiency of the developed a-Si:H/poly-Si/poly-Si stacked solar cell exhibits the efficiency of 11.5%.

  13. Development of MoOx thin films as back contact buffer for CdTe solar cells in substrate configuration

    International Nuclear Information System (INIS)

    Molybdenum oxide compounds exhibit unique electrical and optical properties depending on oxygen vacancy concentration and composition and therefore, have recently attracted a lot of attention as a hole transport layer in various devices. In this work CdTe solar cells in substrate configuration were grown with evaporated MoOx back contact buffer layers and efficiencies of up to 10% could be achieved without using Cu in the back contact processing. The buffer layer – at the CdTe/back contact interface – in the finished cell was found to consist of MoO2 phase instead of the expected MoO3 phase as observed in as-deposited or annealed MoOx layers without CdTe deposition. In order to obtain MoOx buffer layers with desired stoichiometry, MoOx thin films were deposited by radio-frequency sputtering under different growth conditions. The chemical phase, composition, microstructure and optical properties of such layers were studied for their possible use in CdTe solar cells. - Highlights: ? MoOx is used as a back contact buffer in CdTe solar cells in substrate configuration. ? Efficiency of 10.0% was achieved without the addition of Cu. ? The back contact buffer in the finished device consists only of MoO2. ? Phases and microstructure of MoOx can be controlled by sputtering conditions

  14. Comparative study on the annealing types on the properties of Cu2ZnSnS4 thin films and their application to solar cells

    Science.gov (United States)

    Hong, Chang Woo; Shin, Seung Wook; Gurav, K. V.; Vanalakar, S. A.; Yeo, Soo Jung; Yang, Han Seung; Yun, Jae Ho; Kim, Jin Hyeok

    2015-04-01

    Comparative studies on the properties of Cu2ZnSnS4 (CZTS) thin films and performance of CZTS thin film solar cells (TFSCs) prepared by different sulfurization types such as commerical furnace (CF) and rapid thermal annealing (RTA) systems have been investigated. The CZTS thin film prepared using CF showed the dense microstructure with many voids and secondary phases, while that prepared using RTA showed the dense microstructure without void and with some secondary phases. The RTA annealed CZTS TFSC have shown better performance than that prepared using CF. The best performance of CZTS TFSC using RTA was 1.9% efficiency (Voc: 505 mV, Jsc: 7.5 mA/cm2 and FF: 50.2%).

  15. A Study on the Development of Organic Thin Film Solar Cell Device With Optimized Hole Transfer Layer of PEDOT:PSS

    OpenAIRE

    Paik-Kyun Shin; Kumar Palanisamy; Abhirami Kumar; Katsuhiko Kato; Shizuyasu Ochiai

    2013-01-01

    Organic thin film solar cells show generally lower power conversion efficiencies than those of the solar cells based on inorganic active materials. To solve the problem diverse research works have been tried: development of new organic semiconductors; modification of internal structure of active layers by means of organic solvent; design and fabrication of vertical device structure; introduction of buffer layer on the side of cathode electrode. Nevertheless, the buffer layer on the side of an...

  16. Thin films of polyfluorene:fullerene blends - Morphology and its role in solar cell performance

    OpenAIRE

    Björström Svanström, Cecilia

    2007-01-01

    The sun provides us daily with large quantities of energy in the form of light. With the world’s increasing demand of electrical energy the prospect of converting this solar light into electricity is highly tempting. In the strive towards mass-production and low cost solar cells, new types of solar cells are being developed, e.g. solar cells completely based on organic molecules and polymers. These materials offer a promising potential of low cost and large scale manufacturing and have the ad...

  17. Efficient water-splitting device based on a bismuth vanadate photoanode and thin-film silicon solar cells.

    Science.gov (United States)

    Han, Lihao; Abdi, Fatwa F; van de Krol, Roel; Liu, Rui; Huang, Zhuangqun; Lewerenz, Hans-Joachim; Dam, Bernard; Zeman, Miro; Smets, Arno H M

    2014-10-01

    A hybrid photovoltaic/photoelectrochemical (PV/PEC) water-splitting device with a benchmark solar-to-hydrogen conversion efficiency of 5.2% under simulated air mass (AM) 1.5 illumination is reported. This cell consists of a gradient-doped tungsten-bismuth vanadate (W:BiVO4 ) photoanode and a thin-film silicon solar cell. The improvement with respect to an earlier cell that also used gradient-doped W:BiVO4 has been achieved by simultaneously introducing a textured substrate to enhance light trapping in the BiVO4 photoanode and further optimization of the W gradient doping profile in the photoanode. Various PV cells have been studied in combination with this BiVO4 photoanode, such as an amorphous silicon (a-Si:H) single junction, an a-Si:H/a-Si:H double junction, and an a-Si:H/nanocrystalline silicon (nc-Si:H) micromorph junction. The highest conversion efficiency, which is also the record efficiency for metal oxide based water-splitting devices, is reached for a tandem system consisting of the optimized W:BiVO4 photoanode and the micromorph (a-Si:H/nc-Si:H) cell. This record efficiency is attributed to the increased performance of the BiVO4 photoanode, which is the limiting factor in this hybrid PEC/PV device, as well as better spectral matching between BiVO4 and the nc-Si:H cell. PMID:25138735

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

    Energy Technology Data Exchange (ETDEWEB)

    Trefny, J U; Mao, D [Colorado School of Mines, Golden, CO (United States)

    1997-04-01

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

  19. Pyrolysis preparation of Cu2ZnSnS4 thin film and its application to counter electrode in quantum dot-sensitized solar cells

    International Nuclear Information System (INIS)

    The Cu2ZnSnS4 (CZTS) thin films with uniform and porous surface feature with the pore size of 100-200 nm were successfully prepared by pyrolysis procedure using the methanol solution containing copper chloride dihydrate (0.06 mol dm?3), zinc chloride (0.03 mol dm?3), stannous chloride dihydrate (0.03 mol dm?3), thiourea (0.48 mol dm?3) and deionized water (1.92 mol dm?3) as precursor solution at 380°C in air atmosphere. Electrochemical impedance spectroscopy was applied to evaluate the electrochemical catalytic activity of the pyrolysis CZTS thin films for redox couple of Sn2-/S2? and the charge transfer resistance was 64.08 ? using the pyrolysis CZTS thin film obtained by repeating the procedure of dipping the FTO substrate into the precursor solution and heating at 380°C for 7 cycles. The assembled quantum dot-sensitized solar cells gave an open-circuit photovoltage of 0.52 V, a short-circuit photocurrent density of 12.96 mA cm?2, and a fill factor of 0.38, corresponding to the photoelectric conversion efficiency of 2.56%. Because the pyrolysis procedure was a facile, low cost and vacuum-free process, and had the advantage of obtaining various porous microstructure thin films and allowing deposition over large areas, the pyrolysis CZTS thin films can serve as an effective counter electrode for QDSCs

  20. Influence of sulfurization pressure on Cu2ZnSnS4 thin films and solar cells prepared by sulfurization of metallic precursors

    Science.gov (United States)

    He, Jun; Sun, Lin; Chen, Ye; Jiang, Jinchun; Yang, Pingxiong; Chu, Junhao

    2015-01-01

    Effects of sulfurization pressure on composition, morphology and microstructure of kesterite Cu2ZnSnS4 (CZTS) thin films obtained by sulfurization of the metallic layers have been investigated in detail. It is found that the S content in the CZTS thin films is strongly dependent on the sulfurization pressure. The CZTS thin films sulfurized under low sulfurization pressure have S-poor state with a bilayer structure, while it exhibits sufficient amounts of sulfur under high sulfurization pressure with grain growth throughout the entire absorber film. X-ray diffraction data indicate lower sulfurization pressure during the CZTS grain growth process can induce the formation of more structural defects in the CZTS lattice and the CZTS thin films sulfurized under high sulfurization pressure have more random orientation. Furthermore, ZnS and MoS2 phase exist in all samples determined by Fourier transform infrared reflectance spectroscopy as complementary to Raman spectroscopy. The solar cell fabricated with the CZTS thin film under 10 Torr sulfurization pressure shows the best conversion efficiency of 3.52% (VOC = 484 mV, JSC = 14.56 mA cm-2, FF = 50.1%).

  1. Low cost CuInSe2 thin films production by stacked elemental layers process for large area fabrication of solar cell application

    International Nuclear Information System (INIS)

    Highlights: ? CuInSe2 (CIS) thin film has deposited by stacked elemental layer technique (SEL). ? CuInSe2 phase have been obtained after annealing at temperature 350 °C. ? The structural, morphology and electrical properties have been obtained. ? The red shift in energy band gap of CIS thin films are found due to annealing. - Abstract: Low cost deposition of large area CuInSe2 (CIS) thin films have been grown on Mo-coated glass substrate by simple and economic stacked elemental layer deposition technique in vacuum. The grown parameters such as concentration of Cu, In and Se elements have been optimized to achieve uniform thin film in vacuum chamber. The as-grown Cu/In/Se stacked layers have been annealed at 200 °C and 350 °C for 1 h in air ambient. The as-grown and annealed films have been further subjected to characterization by X-ray diffraction (XRD), optical absorption, atomic force microscopy (AFM) and I–V measurement techniques. XRD patterns revealed that as-grown Cu/In/Se stacked layers represent amorphous nature while annealed CIS film reproduces nano-polycrystalline nature with chalcopyrite structure. The optical band gap of annealed films increases with respect to air annealing which confirms the reduction of crystallite size. Surface morphology of as-grown Cu/In/Se stacked layers and annealed CIS thin films have been confirmed by AFM images. The electrical measurements show enhancement of conductivity which is useful for solar cell application.

  2. Cu2ZnSnS4 thin film solar cells from electroplated precursors: Novel low-cost perspective

    International Nuclear Information System (INIS)

    Thin-film solar cells based on Cu2ZnSnS4 (CZTS) absorbers were fabricated successfully by solid-state reaction in H2S atmosphere of electrodeposited Cu-Zn-Sn precursors. These ternary alloys were deposited in one step from a cyanide-free alkaline electrolyte containing Cu(II), Zn (II) and Sn (IV) metal salts on Mo-coated glass substrates. The solar cell was completed by a chemical bath-deposited CdS buffer layer and a sputtered i-ZnO/ZnO:Al bilayer. The best solar cell performance was obtained with Cu-poor samples. A total area (0.5 cm2) efficiency of 3.4% is achieved (Voc = 563 mV, jsc = 14.8 mA/cm2, FF = 41%) with a maximum external quantum efficiency (EQE) of 80%. The estimated band-gap energy from the external quantum efficiency (EQE) measurements is about 1.54 eV. Electron backscatter-diffraction maps of cross-section samples revealed CZTS grain sizes of up to 10 ?m. Elemental distribution maps of the CZTS absorber show Zn-rich precipitates, probably ZnS, and a Zn-poor region, presumably Cu2SnS3, close to the interface Mo/CZTS

  3. Effect of oxygen to argon flow ratio on the properties of Al-doped ZnO films for amorphous silicon thin film solar cell applications

    International Nuclear Information System (INIS)

    Transparent conductive oxide thin films in solar cell fabrication have attracted much attention due to their high conductivity and transmittance. In this paper, we have investigated the aluminum-doped zinc oxide (AZO) thin films prepared by radiofrequency magnetron sputtering on Asahi U-type SnO2 glass with different O2/Ar flow ratios in vacuum chamber. Furthermore, the micro-structural, electrical, and optical properties of AZO/SnO2 films were studied. The change in O2/Ar flow ratios is found to significantly affect the haze value, and slightly affect electrical resistivity and transmittance of the films. Afterward, the fabricated AZO thin films with different O2/Ar flow ratios were used for building the solar cell devices. The current–voltage and external quantum efficiency characteristics were investigated for the solar cell devices. The optimized O2/Ar flow ratio of 3 for solar device shows the best efficiency of 10.41%, and a 20% increase in short-circuit current density compared to typical Asahi solar cells. - Highlights: ? A thin Al-doped zinc oxide (AZO) film has been deposited on SnO2 substrates. ? The AZO film deposited at an O2/Ar ratio of 3 shows low resistivity and high haze. ? The AZO film contains tiny grains that enhance light scattering. ? The amorphous silicon solar cell with the AZO layer shows a 20% increase in Jsc

  4. Effect of oxygen to argon flow ratio on the properties of Al-doped ZnO films for amorphous silicon thin film solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Yang-Shih [Department of Materials Science and Engineering, National Chung Hsing University, Taichung 402, Taiwan, ROC (China); Lien, Shui-Yang, E-mail: syl@mdu.edu.tw [Department of Materials Science and Engineering, MingDao University, ChangHua 52345, Taiwan, ROC (China); Huang, Yung-Chuan [Department of Materials Science and Engineering, MingDao University, ChangHua 52345, Taiwan, ROC (China); Wang, Chao-Chun [Department of Materials Science and Engineering, National Chung Hsing University, Taichung 402, Taiwan, ROC (China); Liu, Chueh-Yang [Department of Materials Science and Engineering, MingDao University, ChangHua 52345, Taiwan, ROC (China); Nautiyal, Asheesh [Department of Mechanical Engineering, Yuan Ze University, 135 Yuan-Tung Road, Chungli, 320 Taoyuan, Taiwan, ROC (China); Wuu, Dong-Sing [Department of Materials Science and Engineering, National Chung Hsing University, Taichung 402, Taiwan, ROC (China); Lee, Shuo-Jun [Department of Mechanical Engineering, Yuan Ze University, 135 Yuan-Tung Road, Chungli, 320 Taoyuan, Taiwan, ROC (China)

    2013-02-01

    Transparent conductive oxide thin films in solar cell fabrication have attracted much attention due to their high conductivity and transmittance. In this paper, we have investigated the aluminum-doped zinc oxide (AZO) thin films prepared by radiofrequency magnetron sputtering on Asahi U-type SnO{sub 2} glass with different O{sub 2}/Ar flow ratios in vacuum chamber. Furthermore, the micro-structural, electrical, and optical properties of AZO/SnO{sub 2} films were studied. The change in O{sub 2}/Ar flow ratios is found to significantly affect the haze value, and slightly affect electrical resistivity and transmittance of the films. Afterward, the fabricated AZO thin films with different O{sub 2}/Ar flow ratios were used for building the solar cell devices. The current–voltage and external quantum efficiency characteristics were investigated for the solar cell devices. The optimized O{sub 2}/Ar flow ratio of 3 for solar device shows the best efficiency of 10.41%, and a 20% increase in short-circuit current density compared to typical Asahi solar cells. - Highlights: ? A thin Al-doped zinc oxide (AZO) film has been deposited on SnO{sub 2} substrates. ? The AZO film deposited at an O{sub 2}/Ar ratio of 3 shows low resistivity and high haze. ? The AZO film contains tiny grains that enhance light scattering. ? The amorphous silicon solar cell with the AZO layer shows a 20% increase in Jsc.

  5. Na-Doped Mo Target Sputtering for CIGS Thin Film Solar Cells on Stainless Steel Substrate

    Directory of Open Access Journals (Sweden)

    Y. C. Lin

    2013-05-01

    Full Text Available This study deposited Cu(In,GaSe2(CIGS thin films on Mo/SiOx/SS431 substrates using magnetron sputtering. Our objectives were to introduce a Mo-5%Na target as a source of incorporate Na to the chalcopyrite structure and investigate its influence on the crystallinity of CIGS thin films. Experimental results demonstrate that adding Na in this manner can enhance the distribution of Na on the surface as well as the depth profile. When the thickness ratio of Mo-5%Na: Mo was 2.8%, the atomic ratio of Na was 0.48%, which enhanced crystallinity of CIGS. Excess Na dopant led to the formation of NaInSe2 phase, which increases the number of In vacancies in chalcopyrite, thereby reducing crystallinity. The results of bending tests demonstrate that the adhesion of SiOx to SS431 is superior to the adhesion of SiOx to Mo.

  6. 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. PMID:24377257

  7. Crystalline silicon carbide intermediate layers for silicon thin-film solar cells

    OpenAIRE

    Schillinger, Kai

    2014-01-01

    This work describes a concept to create photovoltaically active silicon thin-films on ceramic substrates. To achieve this, the ceramics are coated with a diffusion barrier of crystalline silicon carbide. On top of the diffusion barrier the light absorbing silicon layer is created by zone-melting recrystallization of poly-silicon and subsequent epitaxial thickening of the absorber layer. All the processing steps were hereby performed at atmospheric pressure, to allow high throughput and low co...

  8. Conductive atomic force microscopy on hydrogenated microcrystalline silicon and polycrystalline silicon thin films for solar cells.

    Czech Academy of Sciences Publication Activity Database

    Vetushka, Aliaksi; Fejfar, Antonín; Ledinský, Martin; Stuchlík, Ji?í; Ko?ka, Jan

    Tokyo : Tokyo Institute of Technology Global COE Program, 2010 - (Hirai, S.; Maruyama, T.), s. 23-24 ISBN N. [International Forum on Multidisciplinary Education and Research for Energy Science /3./. Ishigaki, Okinawa (JP), 09.12.2010-14.12.2010] EU Projects: European Commission(XE) 240826 Institutional research plan: CEZ:AV0Z10100521 Keywords : thin films of polycrystalline silicon * microcrystalline silicon Subject RIV: BM - Solid Matter Physics ; Magnetism

  9. Light trapping in thin film silicon solar cells by Raman spectroscopy.

    Czech Academy of Sciences Publication Activity Database

    Ganzerová, Kristína; Ledinský, Martin; Fejfar, Antonín; Ko?ka, Jan

    Tokyo : ACEEES, Tokyo Institute of Technology , 2013. s. 1-2. [International Education Forum on Enviroment and Energy Science /2./. 13.12.2013-17.12.2013, Los Angeles] R&D Projects: GA MPO FR-TI2/736; GA MŠk(CZ) LM2011026 Grant ostatní: AV?R(CZ) M100101216; AV ?R(CZ) M100101217 Institutional support: RVO:68378271 Keywords : Raman spectroscopy * thin film Subject RIV: BM - Solid Matter Physics ; Magnetism

  10. On the diffusion length and grain size homogeneity requirements for efficient thin-film polycrystalline silicon solar cells

    International Nuclear Information System (INIS)

    We examine the influence of intragrain defects and grain boundaries on the macroscopic performance of a thin film polycrystalline silicon solar cell. In addition, we evaluate the effect of grain size inhomogeneity on the cell performance via circuit simulations. From an analytical study of charge transport in individual grains and homogeneous grain systems, we obtain the grain size and intragrain diffusion length requirements for a desired efficiency. We identify the conditions under which the grain size and the intragrain diffusion length dominate the cell characteristics. In devices with intragrain effective diffusion length Lmono ? 100 µm and grain boundary recombination velocity SGB ? 104 cm s-1, achieving a larger grain size beyond several µm is not crucial. The inhomogeneous distribution circuit simulations show that grain size inhomogeneity is not the main limiting factor in polycrystalline silicon solar cells. This is so even in thin polycrystalline silicon films with a broad grain size distribution such as those made with aluminum-induced crystallization at low annealing temperature. The main reason is that the optimum bias point for grains of different sizes only differ by about ?50 mV over a fairly wide grain diameter range 0.5-50 µm even when Lmono = 100 µm and SGB = 105 cm s-1.

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

    Science.gov (United States)

    Yi, Yasha (Somerville, MA); Kimerling, Lionel C. (Concord, MA); Duan, Xiaoman (Amesbury, MA); Zeng, Lirong (Cambridge, MA)

    2009-01-27

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

  12. Photocurrent Increase in Thin Film Solar Cells by Guided Mode Excitation

    OpenAIRE

    Söderström, Karin; Escarre Palou, Jordi; Garcia, Cubero; Jesus, Oscar; Haug, Franz-Josef; Ballif, Christophe

    2010-01-01

    Angle resolved measurements of the external quantum efficiency of a-Si solar cells deposited on a grating show strong absorption phenomena which are well explained with the guided mode structure in an equivalent flat multilayer system.

  13. Separation of signals from amorphous and microcrystalline part of a tandem thin film silicon solar cell in Fourier transform photocurrent spectroscopy.

    Czech Academy of Sciences Publication Activity Database

    Holovský, Jakub; Poruba, Aleš; Bailat, J.; Van??ek, Milan

    München : WIP- Renewable Energies, 2007 - (Willeke, G.; Ossenbrink, H.; Helm, P.), s. 1851-1854 ISBN 3-936338-22-1. [European Photovoltaic Solar Energy Conference /22./. Milan (IT), 03.09.2007-07.09.2007] R&D Projects: GA MŽP(CZ) SN/3/172/05 Keywords : thin film silicon solar cell * Fourier transform photocurrent spectroscopy Subject RIV: BM - Solid Matter Physics ; Magnetism

  14. A new approach to the manufacture of chalcogenide thin film solar cells

    International Nuclear Information System (INIS)

    Glass beads of 0.2 mm diameter are covered with molybdenum, copper and indium. The copper/indium layers are transformed into copper indium disulfide (CIS) by exposing the glass beads to a hydrogensulfide/argon mixture at temperatures of around 500 oC. The CIS covered glass beads serve as the basis material for the formation of solar cells. The main advantage of this approach is the separation between absorber and cell/module formation. In this paper the different process steps necessary for cell manufacturing are described. Some properties of solar cells made out of CIS covered glass beads are presented

  15. Auger generation effect on the thermodynamic efficiency of Cu(In,Ga)Se2 thin film solar cells

    International Nuclear Information System (INIS)

    The effect of Auger generation on the thermodynamic efficiency of a reverse graded band gap Cu(In,Ga)Se2 thin film solar cell is studied using a detailed balance approach. For the graded profile (1.5–1 eV), a wider range of photons can be considered as high energy photons to produce hot electrons which can pump an additional electron from the valence band to the conduction band. The effects of the carrier multiplication probability, P, and grading strength of the front band gap on the variation of efficiency are studied. Auger mechanism is more effective at lower band gaps due to higher multiplication probability. A thermodynamic efficiency of about 41% is obtained, which is higher than the maximum efficiency of 31% for a graded band gap cell without Auger generation. Moreover, we study the effect of Auger generation on the current–voltage characteristics of the cell. The carrier multiplication increases the short-circuit current due to the increased photogenerated electrons and almost does not change the open-circuit voltage. However, the band gap grading enhances the open-circuit voltage by reducing the recombination rate. Also, a known result is the red shift in the optimum band gap towards a lower band gap (1.15 eV) with respect to the Shockley–Queisser limit. - Highlights: • Auger generation has been considered in a graded band gap Cu(In,Ga)Se2 solar cell • Carrier multiplication increases the efficiency of the chalcogenide solar cells • Cu(In,Ga)Se2 is a promising material for solar cells due to carrier effective mass

  16. Study of the junction and carrier lifetime properties of a spray-deposited CZTS thin-film solar cell

    International Nuclear Information System (INIS)

    The Cu2ZnSnS4 (CZTS) thin-film solar cell fabricated entirely by a spray pyrolysis process was investigated under diffused white light in the present study. A CdS layer was developed as a heterojunction partner. The structural, morphological and photovoltaic characterization of an as-prepared stoichiometric CZTS film was carried out. The diode ideality factor n was found to be in the range of 1.2–5.6 in the forward bias region and it is explained by the Frenkel–Poole conduction model. The solar cell exhibited open-circuit voltage (Voc) of 157.25 mV, short-circuit current density (Jsc) of 3.024 mA cm?2 and fill factor (FF) of 24.77% at an incident irradiance of 200 W m?2 from the white LED source. The effective minority carrier lifetime of 263 ?s was confirmed by the open-circuit voltage decay fitting under pulsed monochromatic LED excitation. (paper)

  17. Study of the junction and carrier lifetime properties of a spray-deposited CZTS thin-film solar cell

    Science.gov (United States)

    Patel, Malkeshkumar; Mukhopadhyay, Indrajit; Ray, Abhijit

    2013-05-01

    The Cu2ZnSnS4 (CZTS) thin-film solar cell fabricated entirely by a spray pyrolysis process was investigated under diffused white light in the present study. A CdS layer was developed as a heterojunction partner. The structural, morphological and photovoltaic characterization of an as-prepared stoichiometric CZTS film was carried out. The diode ideality factor n was found to be in the range of 1.2-5.6 in the forward bias region and it is explained by the Frenkel-Poole conduction model. The solar cell exhibited open-circuit voltage (Voc) of 157.25 mV, short-circuit current density (Jsc) of 3.024 mA cm-2 and fill factor (FF) of 24.77% at an incident irradiance of 200 W m-2 from the white LED source. The effective minority carrier lifetime of 263 ?s was confirmed by the open-circuit voltage decay fitting under pulsed monochromatic LED excitation.

  18. Grazing incidence X-ray fluorescence analysis of buried interfaces in periodically structured crystalline silicon thin-film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Eisenhauer, David; Preidel, Veit; Becker, Christiane [Young Investigator Group Nanostructured Silicon for Photovoltaic and Photonic Implementations (Nano-SIPPE), Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Berlin (Germany); Pollakowski, Beatrix; Beckhoff, Burkhard [Physikalisch-Technische Bundesanstalt, Berlin (Germany); Baumann, Jonas; Kanngiesser, Birgit [Institut fuer Optik und Atomare Physik, Technische Universitaet Berlin (Germany); Amkreutz, Daniel; Rech, Bernd [Institut Silizium Photovoltaik, Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Berlin (Germany); Back, Franziska; Rudigier-Voigt, Eveline [SCHOTT AG, Mainz (Germany)

    2015-03-01

    We present grazing incidence X-ray fluorescence (GIXRF) experiments on 3D periodically textured interfaces of liquid phase crystallized silicon thin-film solar cells on glass. The influence of functional layers (SiO{sub x} or SiO{sub x}/SiC{sub x}) - placed between glass substrate and silicon during crystallization - on the final carbon and oxygen contaminations inside the silicon was analyzed. Baring of the buried structured silicon surface prior to GIXRF measurement was achieved by removal of the original nano-imprinted glass substrate by wet-chemical etching. A broad angle of incidence distribution was determined for the X-ray radiation impinging on this textured surface. Optical simulations were performed in order to estimate the incident radiation intensity on the structured surface profile considering total reflection and attenuation effects. The results indicate a much lower contamination level for SiO{sub x} compared to the SiO{sub x}/SiC{sub x} interlayers, and about 25% increased contamination when comparing structured with planar silicon layers, both correlating with the corresponding solar cell performances. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. Grazing incidence X-ray fluorescence analysis of buried interfaces in periodically structured crystalline silicon thin-film solar cells

    International Nuclear Information System (INIS)

    We present grazing incidence X-ray fluorescence (GIXRF) experiments on 3D periodically textured interfaces of liquid phase crystallized silicon thin-film solar cells on glass. The influence of functional layers (SiOx or SiOx/SiCx) - placed between glass substrate and silicon during crystallization - on the final carbon and oxygen contaminations inside the silicon was analyzed. Baring of the buried structured silicon surface prior to GIXRF measurement was achieved by removal of the original nano-imprinted glass substrate by wet-chemical etching. A broad angle of incidence distribution was determined for the X-ray radiation impinging on this textured surface. Optical simulations were performed in order to estimate the incident radiation intensity on the structured surface profile considering total reflection and attenuation effects. The results indicate a much lower contamination level for SiOx compared to the SiOx/SiCx interlayers, and about 25% increased contamination when comparing structured with planar silicon layers, both correlating with the corresponding solar cell performances. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Silicon-Light: a European project aiming at high efficiency thin film silicon solar cells on foil

    Directory of Open Access Journals (Sweden)

    Soppe W.

    2014-07-01

    Full Text Available In the European project Silicon-Light we developed concepts and technologies to increase conversion efficiencies of thin film silicon solar cells on foil. Main focus was put on improved light management, using NIL for creating light scattering textures, improved TCOs using sputtering, and improved silicon absorber material made by PECVD. On foil we achieved initial cell efficiencies of 11% and on rigid substrates stable efficiencies of 11.6% were achieved. Finally, the project demonstrated the industrial scale feasibility of the developed technologies and materials. Cost of ownership calculations showed that implementation of these technologies on large scale would enable the production of these high efficiency solar modules at manufacturing cost of 0.65 €/Wp with encapsulation costs (0.20 €/Wp being the dominant costs. Life cycle analysis showed that large scale production of modules based on the technologies developed in Silicon-Light would have an energy payback time of 0.85 years in Central European countries.

  1. Mapping electronic properties of the thin films for solar cells with nanometer resolution.

    Czech Academy of Sciences Publication Activity Database

    Fejfar, Antonín; Rezek, Bohuslav; Mates, Tomáš; Honda, Shinya; ?ermák, Jan; Ledinský, Martin; Vetushka, Aliaksi; Stuchlík, Ji?í; Stuchlíková, The-Ha; Šípek, Emil; Ko?ka, Jan

    Tokyo : Japan Society for the Promotion of Science, 2008, s. 62-66. [Workshop on the Future Direction of Photovoltaics /4./. Aogaku Kaikan, Tokyo (JP), 06.03.2008-07.03.2008] R&D Projects: GA MŠk(CZ) LC06040; GA AV ?R KAN400100701; GA MŠk LC510; GA MŽP(CZ) SN/3/172/05 Institutional research plan: CEZ:AV0Z10100521 Keywords : silicon * thin films * photovoltaics Subject RIV: BM - Solid Matter Physics ; Magnetism

  2. Sputtered of ZnO:Al thin Films for Application in Photovoltaic Solar Cells

    Directory of Open Access Journals (Sweden)

    Sona Flickyngerova

    2008-01-01

    Full Text Available High transparent and conductive, aluminium - doped zinc oxide thin films (ZnO:Al, were prepared by radio –frequency (RF diode sputtering from ZnO+2 wt. % Al2O3 target on Eutal glass substrates. Surfaces of the samples weretreated by various technological steps during preparation. The ion bombardment and the substrate temperature modified theirstructure, surface morphology, electrical and optical parameters. In this work we present changes between samples preparedat room temperature (RT and at 200°C, between samples on ion etched substrate and non-modified substrate, and effect ofion etching of the sample surface. We measured transmittance, resistivity and microroughness by AFM on all samples.

  3. Diode laser crystallization processes of Si thin-film solar cells on glass

    OpenAIRE

    Yun Jae Sung; Ahn Cha Ho; Jung Miga; Huang Jialiang; Kim Kyung Hun; Varlamov Sergey; Green Martin A.

    2014-01-01

    The crystallization of Si thin-film on glass using continuous-wave diode laser is performed. The effect of various processing parameters including laser power density and scanning speed is investigated in respect to microstructure and crystallographic orientation. Optimal laser power as per scanning speed is required in order to completely melt the entire Si film. When scan speed of 15–100 cm/min is used, large linear grains are formed along the laser scan direction. Laser scan speed over 100...

  4. Development of Rear Surface Passivated Cu(In,Ga)Se2 Thin Film Solar Cells with Nano-Sized Local Rear Point Contacts

    OpenAIRE

    Vermang, Bart; Fjällström, Viktor; Pettersson, Jonas; Salomé, Pedro; Edoff, Marika

    2013-01-01

    For the first time, a novel rear contacting structure for copper indium gallium (di)selenide (CIGS) thin film solar cells is discussed theoretically, developed in an industrially viable way, and demonstrated in tangible devices. The proposed cell design reduces back contacting area by combining a rear surface passivation layer and nano-sized local point contacts. Atomic layer deposition (ALD) of Al2O3 is used to passivate the CIGS surface and the formation of nano-sphere shaped precipitates i...

  5. Efficient hole-blocking layer-free planar halide perovskite thin-film solar cells

    Science.gov (United States)

    Ke, Weijun; Fang, Guojia; Wan, Jiawei; Tao, Hong; Liu, Qin; Xiong, Liangbin; Qin, Pingli; Wang, Jing; Lei, Hongwei; Yang, Guang; Qin, Minchao; Zhao, Xingzhong; Yan, Yanfa

    2015-03-01

    Efficient lead halide perovskite solar cells use hole-blocking layers to help collection of photogenerated electrons and to achieve high open-circuit voltages. Here, we report the realization of efficient perovskite solar cells grown directly on fluorine-doped tin oxide-coated substrates without using any hole-blocking layers. With ultraviolet-ozone treatment of the substrates, a planar Au/hole-transporting material/CH3NH3PbI3-xClx/substrate cell processed by a solution method has achieved a power conversion efficiency of over 14% and an open-circuit voltage of 1.06?V measured under reverse voltage scan. The open-circuit voltage is as high as that of our best reference cell with a TiO2 hole-blocking layer. Besides ultraviolet-ozone treatment, we find that involving Cl in the synthesis is another key for realizing high open-circuit voltage perovskite solar cells without hole-blocking layers. Our results suggest that TiO2 may not be the ultimate interfacial material for achieving high-performance perovskite solar cells.

  6. Potential of thin-film silicon solar cells by using high haze TCO superstrates

    International Nuclear Information System (INIS)

    Potential improvements in the performance of tandem amorphous silicon/microcrystalline silicon (a-Si:H/?c-Si:H) solar cells, related to the TCO superstrates with enhanced scattering properties are studied. In particular, optical effects of a high haze double textured (W-textured) SnO2:F TCO superstrate are analyzed and compared to the properties of the pyramidal type SnO2:F TCO superstrate. Solar cell with W-textured superstrate exhibits higher long-wavelength external quantum efficiency of the bottom ?c-Si:H cell than the one with pyramidal type TCO superstrate. Optical simulations are employed to study the potential improvements of the solar cell performance if ideal haze parameter (H = 1) and/or a broad angular distribution function (Lambertian) of scattered light are applied to textured interfaces in the solar cell structure. Simulations reveal significant improvements in long-wavelength quantum efficiencies if a broad angular distribution function of scattered light is applied. Optical losses in the cells with enhanced scattering properties are analysed and evaluated in terms of short-circuit current losses in the supporting layers and losses due to reflected light.

  7. Multi-junction Thin-film Solar Cells on Flexible Substrates for Space Power

    Science.gov (United States)

    Hepp, Aloysius F.; Smith, Mark; Scofield, John H.; Dickman, John E.; Lush, Gregory B.; Morel, Donald L.; Ferekides, Christos; Dhere, Neelkanth G.

    2002-01-01

    The ultimate objective of the thin-film program at NASA GRC is development of a 20 percent AM0 thin-film device technology with high power/weight ratio. Several approaches are outlined to improve overall device efficiency and power/weight ratio. One approach involves the use of very lightweight flexible substrates such as polyimides (i.e., Kapton(Trademark)) or metal foil. Also, a compound semiconductor tandem device structure that can meet this objective is proposed and simulated using Analysis of Microelectronic and Photonic Structures (AMPS). AMPS modeling of current devices in tandem format indicate that AM0 efficiencies near 20 percent can be achieved. And with improvements in materials, efficiencies approaching 25 percent are achievable. Several important technical issues need to be resolved to realize these complex devices: development of a wide bandgap material with good electronic properties, development of transparent contacts, and targeting a 2-terminal device structure (with more complicated processing and tunnel junction) or 4-terminal device. Recent progress in the NASA GRC program is outlined.

  8. Chemical interaction at the buried silicon/zinc oxide thin-film solar cell interface as revealed by hard X-ray photoelectron spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Wimmer, M., E-mail: mark.wimmer@helmholtz-berlin.de [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Gerlach, D.; Wilks, R.G.; Scherf, S.; Félix, R. [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Lupulescu, C. [Institute for Optics and Atomic Physics, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin (Germany); Ruske, F.; Schondelmaier, G.; Lips, K. [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Hüpkes, J. [Institute for Energy Research, Forschungszentrum Jülich GmbH, Leo-Brandt-Straße, 52425 Jülich (Germany); Gorgoi, M. [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Eberhardt, W. [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Institute for Optics and Atomic Physics, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin (Germany); Rech, B. [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Bär, M., E-mail: marcus.baer@helmholtz-berlin.de [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Institut für Physik und Chemie, Brandenburgische Technische Universität Cottbus, Konrad-Wachsmann-Allee 1, 03046 Cottbus (Germany)

    2013-10-15

    Highlights: •We used HAXPES to identify chemical interactions at the buried silicon/aluminum-doped zinc oxide thin-film solar cell interface. •The results indicate a diffusion of zinc and aluminum into the silicon upon annealing procedures which are part of the solar cell processing. •The contamination of the silicon may be detrimental for the solar cell performance. -- Abstract: Hard X-ray photoelectron spectroscopy (HAXPES) is used to identify chemical interactions (such as elemental redistribution) at the buried silicon/aluminum-doped zinc oxide thin-film solar cell interface. Expanding our study of the interfacial oxidation of silicon upon its solid-phase crystallization (SPC), in which we found zinc oxide to be the source of oxygen, in this investigation we address chemical interaction processes involving zinc and aluminum. In particular, we observe an increase of zinc- and aluminum-related HAXPES signals after SPC of the deposited amorphous silicon thin films. Quantitative analysis suggests an elemental redistribution in the proximity of the silicon/aluminum-doped zinc oxide interface – more pronounced for aluminum than for zinc – as explanation. Based on these insights the complex chemical interface structure is discussed.

  9. Chemical interaction at the buried silicon/zinc oxide thin-film solar cell interface as revealed by hard X-ray photoelectron spectroscopy

    International Nuclear Information System (INIS)

    Highlights: •We used HAXPES to identify chemical interactions at the buried silicon/aluminum-doped zinc oxide thin-film solar cell interface. •The results indicate a diffusion of zinc and aluminum into the silicon upon annealing procedures which are part of the solar cell processing. •The contamination of the silicon may be detrimental for the solar cell performance. -- Abstract: Hard X-ray photoelectron spectroscopy (HAXPES) is used to identify chemical interactions (such as elemental redistribution) at the buried silicon/aluminum-doped zinc oxide thin-film solar cell interface. Expanding our study of the interfacial oxidation of silicon upon its solid-phase crystallization (SPC), in which we found zinc oxide to be the source of oxygen, in this investigation we address chemical interaction processes involving zinc and aluminum. In particular, we observe an increase of zinc- and aluminum-related HAXPES signals after SPC of the deposited amorphous silicon thin films. Quantitative analysis suggests an elemental redistribution in the proximity of the silicon/aluminum-doped zinc oxide interface – more pronounced for aluminum than for zinc – as explanation. Based on these insights the complex chemical interface structure is discussed

  10. Development of a Wide Bandgap Cell for Thin Film Tandem Solar Cells: Final Technical Report, 6 November 2003 - 5 January 2007

    Energy Technology Data Exchange (ETDEWEB)

    Shafarman, W.; McCandless, B.

    2008-08-01

    The objective of this research program was to develop approaches for a transparent wide-bandgap cell to be used in a thin-film tandem polycrystalline solar cell that can ultimately attain 25% efficiency. Specific goals included the research and development of Cu(InGa)(SeS)2 and Cd1-xZnxTe alloys with a bandgap from 1.5 to 1.8 eV, demonstrating the potential of a 15% cell efficiency with a transparent contact, and supporting the High Performance PV Program. This Final Report presents results that emphasize the 3rd phase of the program.

  11. Adhesive market develops new technologies. The thin-film solar cells gain ground; El mercado de adhesivos desarrolla nuevas tecnologias. Las celulas solares de capa fina ganan terreno

    Energy Technology Data Exchange (ETDEWEB)

    Kluke, M.

    2010-07-01

    The solar industry is booming. thin-film technology is experiencing a high demand as promised cost advantages and currently is providing excellent results, while a range of efficiency reaches acceptable. (Author)

  12. Influence of an Sb doping layer in CIGS thin-film solar cells: a photoluminescence study

    International Nuclear Information System (INIS)

    Sb doping of Cu(In,Ga)Se2 (CIGS) solar cells has been reported to exhibit a positive effect on the morphology of the absorber layer, offering a possibility to lower manufacturing cost by lowering the annealing temperatures during the CIGS deposition. In this work electron microscopy, energy-dispersive x-ray spectroscopy and photoluminescence experiments have been performed on cells deposited on soda-lime glass substrates, adding a thin Sb layer onto the Mo back contact prior to the CIGS absorber deposition. The defect structure of CIGS solar cells doped with Sb in this way has been investigated and is compared with that of undoped reference cells. The influence of substrate temperature during absorber growth has also been evaluated. For all samples the photoluminescence results can be explained by considering three donor–acceptor pair recombination processes involving the same defect pairs. (paper)

  13. Integration of a 2D Periodic Nanopattern Into Thin Film Polycrystalline Silicon Solar Cells by Nanoimprint Lithography

    CERN Document Server

    Abdo, Islam; Deckers, Jan; Depauw, Valérie; Tous, Loic; Van Gestel, Dries; Guindi, Rafik; Gordon, Ivan; Daif, Ounsi El

    2015-01-01

    The integration of two-dimensional (2D) periodic nanopattern defined by nanoimprint lithography and dry etching into aluminum induced crystallization (AIC) based polycrystalline silicon (Poly-Si) thin film solar cells is investigated experimentally. Compared to the unpatterned cell an increase of 6% in the light absorption has been achieved thanks to the nanopattern which, in turn, increased the short circuit current from 20.6 mA/cm2 to 23.8 mA/cm2. The efficiency, on the other hand, has limitedly increased from 6.4% to 6.7%. We show using the transfer length method (TLM) that the surface topography modification caused by the nanopattern has increased the sheet resistance of the antireflection coating (ARC) layer as well as the contact resistance between the ARC layer and the emitter front contacts. This, in turn, resulted in increased series resistance of the nanopatterned cell which has translated into a decreased fill factor, explaining the limited increase in efficiency.

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

    Science.gov (United States)

    Dhere, Neelkanth G.; Kadam, Ankur A.

    2009-12-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-01-04

    This report describes work done by the University of Toledo during the first year of this subcontract. During this time, the CdTe group constructed a second dual magnetron sputter deposition facility; optimized reactive sputtering for ZnTe:N films to achieve 10 ohm-cm resistivity and {approximately}9% efficiency cells with a copper-free ZnTe:N/Ni contact; identified Cu-related photoluminescence features and studied their correlation with cell performance including their dependence on temperature and E-fields; studied band-tail absorption in CdS{sub x}Te{sub 1{minus}x} films at 10 K and 300 K; collaborated with the National CdTe PV Team on (1) studies of high-resistivity tin oxide (HRT) layers from ITN Energy Systems, (2) fabrication of cells on the HRT layers with 0, 300, and 800-nm CdS, and (3) preparation of ZnTe:N-based contacts on First Solar materials for stress testing; and collaborated with Brooklyn College for ellipsometry studies of CdS{sub x}Te{sub 1{minus}x} alloy films, and with the University of Buffalo/Brookhaven NSLS for synchrotron X-ray fluorescence studies of interdiffusion in CdS/CdTe bilayers. The a-Si group established a baseline for fabricating a-Si-based solar cells with single, tandem, and triple-junction structures; fabricated a-Si/a-SiGe/a-SiGe triple-junction solar cells with an initial efficiency of 9.7% during the second quarter, and 10.6% during the fourth quarter (after 1166 hours of light-soaking under 1-sun light intensity at 50 C, the 10.6% solar cells stabilized at about 9%); fabricated wide-bandgap a-Si top cells, the highest Voc achieved for the single-junction top cell was 1.02 V, and top cells with high FF (up to 74%) were fabricated routinely; fabricated high-quality narrow-bandgap a-SiGe solar cells with 8.3% efficiency; found that bandgap-graded buffer layers improve the performance (Voc and FF) of the narrow-bandgap a-SiGe bottom cells; and found that a small amount of oxygen partial pressure ({approximately}2 {times} 10{sup {minus}5} torr) was beneficial for growing high-quality films from ITO targets.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-06-01

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

  17. High-temperature CVD processes for crystalline silicon thin-film and wafer solar cells

    OpenAIRE

    Schmich, Evelyn Karin

    2008-01-01

    In this thesis, novel in-situ CVD processes have been investigated that promise to decrease the costs and increase cell efficiencies at the same time. The central approach is the epitaxial wafer-equivalent cell structure, consisting of an epitaxial layer deposited on a low-cost silicon substrate. This epitaxial wafer-equivalent (EpiWE) is then processed using a standard solar cell process. The main goal of this thesis project was to improve the quality and the electrical properties of the dep...

  18. Rapid Thermal Annealing and Hydrogen Passivation of Polycrystalline Silicon Thin-Film Solar Cells on Low-Temperature Glass

    Directory of Open Access Journals (Sweden)

    Armin G. Aberle

    2007-12-01

    Full Text Available The changes in open-circuit voltage (Voc, short-circuit current density (Jsc, and internal quantum efficiency (IQE of aLuminum induced crystallization, ion-assisted deposition (ALICIA polycrystalline silicon thin-film solar cells on low-temperature glass substrates due to rapid thermal anneal (RTA treatment and subsequent remote microwave hydrogen plasma passivation (hydrogenation are examined. Voc improvements from 130 mV to 430 mV, Jsc improvements from 1.2 mA/cm2 to 11.3 mA/cm2, and peak IQE improvements from 16% to > 70% are achieved. A 1-second RTA plateau at 1000°C followed by hydrogenation increases the Jsc by a factor of 5.5. Secondary ion mass spectroscopy measurements are used to determine the concentration profiles of dopants, impurities, and hydrogen. Computer modeling based on simulations of the measured IQE data reveals that the minority carrier lifetime in the absorber region increases by 3 orders of magnitude to about 1 nanosecond (corresponding to a diffusion length of at least 1 μm due to RTA and subsequent hydrogenation. The evaluation of the changes in the quantum efficiency and Voc due to RTA and hydrogenation with computer modeling significantly improves the understanding of the limiting factors to cell performance.

  19. Fabrication and characterization methods for growth of CZTS as a promising material for thin film solar cells

    Science.gov (United States)

    Emrani, Amin

    Current research trends are moving towards earth-abundant and low toxicity materials. Cu2ZnSnS4 (CZTS), which consists not only earth-abundant and non-toxic elemental constituents, but also possesses a nearly optimum band gap of 1.5 eV and a high absorption coefficient, has the potential to be a leading material for large scale generation of solar energy. Although theoretical calculations estimated the feasibility of achieving an efficiency between 30 to 40 %, for CZTS solar cells, unfortunately, there is no standard approach to fabricate CZTS cells to reach an efficiency even close to these numbers. In this dissertation, several potential methods from vacuum based techniques such as sputtering to a new solution-based process to deposit CZTS films have been explored, studied and developed. To further improve the CZTS solar cell performance, other layers essential for CZTS solar cells have also been analyzed and optimized. Lastly, the performance and efficiencies of the final integrated cells are presented. First, we report a two-step process with sputtering of elemental precursors followed by sulfurization in dilute H2S. Structural and optical properties of CZTS thin films at various temperatures are studied. The CZTS films formed at 550°C exhibited a compact void-free structure yields the highest efficiency of 5.75%. Since long duration annealing processes are not practical for industry and result in the formation of voids due to the sublimation of secondary phases, fast annealing under sulfur vapor atmosphere has further been investigated. Since the H2S annealing is cleaner and more controllable than dealing with sulfur vapor pressure. We report a two-step process with sputtering of elemental precursors followed by fast sulfurization in dilute H2S. The electrical characteristics and the efficiencies of the respective solar cells were analyzed and compared. The films annealed at 580°C for 30 minutes exhibited the highest efficiency of 3.8%. Another approach to form a uniform precursor is the use of a target consisting of Zn, Sn and Cu. Here we studied the practical issues of using an alloy targets (particularly Cu-Sn alloy target) to deposit CZT layers. Although high-vacuum techniques have already shown promising results, the complex equipment required for such the processes results in costly implementation to scale up. CZTS growth by solution-based methods could potentially provide a low-cost alternative method to fabricate CZTS solar cells in large scale. Here, we introduced and developed a new non-toxic solution-based method to deposit CZTS. Efficiencies of 1.3% have been achieved up to now.

  20. Thin film silicon solar cells: advanced processing and characterization - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Ballif, Ch.

    2008-04-15

    This final report elaborated for the Swiss Federal Office of Energy (SFOE) takes a look at the results of a project carried out at the photovoltaics laboratory at the University of Neuchatel in Switzerland. The project aimed to demonstrate the production of high-efficiency thin-film silicon devices on flexible substrates using low cost processes. New ways of improving processing and characterisation are examined. The process and manufacturing know-how necessary to provide support for industrial partners within the framework of further projects is discussed. The authors state that the efficiency of most devices was significantly improved, both on glass substrates and on flexible plastic foils. The process reproducibility was also improved and the interactions between the different layers in the device are now said to be better understood. The report presents the results obtained and discusses substrate materials, transparent conductors, defect analyses and new characterisation tools. Finally, the laboratory infrastructure is described.

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

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Peizhuan; Hou, Guofu, E-mail: gfhou@nankai.edu.cn; Zhang, Jianjun, E-mail: jjzhang@nankai.edu.cn; Zhang, Xiaodan; Zhao, Ying [Institute of Photoelectronics and Tianjin Key Laboratory of Photoelectronic Thin-film Devices and Technique, Nankai University, Tianjin 300071 (China)

    2014-08-14

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

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

    International Nuclear Information System (INIS)

    For thin-film silicon solar cells (TFSC), a one-dimensional photonic crystal (1D PC) is a good back reflector (BR) because it increases the total internal reflection at the back surface. We used the plane-wave expansion method and the finite difference time domain (FDTD) algorithm to simulate and analyze the photonic bandgap (PBG), the reflection and the absorption properties of a 1D PC and to further explore the optimal 1D PC design for use in hydrogenated amorphous silicon (a-Si:H) solar cells. With identified refractive index contrast and period thickness, we found that the PBG and the reflection of a 1D PC are strongly influenced by the contrast in bilayer thickness. Additionally, light coupled to the top three periods of the 1D PC and was absorbed if one of the bilayers was absorptive. By decreasing the thickness contrast of the absorptive layer relative to the non-absorptive layer, an average reflectivity of 96.7% was achieved for a 1D PC alternatively stacked with a-Si:H and SiO2 in five periods. This reflectivity was superior to a distributed Bragg reflector (DBR) structure with 93.5% and an Ag film with 93.4%. n-i-p a-Si:H solar cells with an optimal 1D PC-based BR offer a higher short-circuit current density than those with a DBR-based BR or an AZO/Ag-based BR. These results provide new design rules for photonic structures in TFSC

  3. Reflectance improvement by thermal annealing of sputtered Ag/ZnO back reflectors in a-Si:H thin film silicon solar cells

    DEFF Research Database (Denmark)

    Haug, Franz-Josef; So?derstro?m, Karin; Pahud, Ce?line; Biron, Re?mi; Escarre?, Jordi; Duchamp, Martial; Dunin-Borkowski, Rafal E.; Ballif, Christophe

    2011-01-01

    Silver can be used as the back contact and reflector in thin film silicon solar cells. When deposited on textured substrates, silver films often exhibit reduced reflectance due to absorption losses by the excitation of surface plasmon resonances. We show that thermal annealing of the silver back reflector increases its reflectance drastically. The process is performed at low temperature (150°C) to allow the use of plastic sheets such as polyethylene naphthalate and increases the efficiency of si...

  4. Silicon nitride anti-reflection coatings for CdS/CuInSe/sub 2/ thin film solar cells by electron beam assisted chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Stanbery, B.J.; Chen, W.S.; Mickelsen, R.A.; Collins, G.J.; Emery, K.A.; Rocca, J.J.; Thompson, L.R.

    1985-07-01

    The electron beam assisted chemical vapor deposition of silicon nitride anti-reflection coatings onto thin film CdS/CuInSe/sub 2/ solar cells and the resultant effects on their performance are reported. In some cases large increases in the short circuit current, open circuit voltage and fill factor were observed. The present results are explained by the usual index matching anti-reflection mechanisms and either the passivation of undesirable shunts or improvement of intrinsic diode characteristics.

  5. Quinoxaline-based ?-conjugated donor polymer for highly efficient organic thin-film solar cells

    Science.gov (United States)

    Kitazawa, Daisuke; Watanabe, Nobuhiro; Yamamoto, Shuhei; Tsukamoto, Jun

    2009-08-01

    A quinoxaline-based ?-conjugated donor polymer, poly[2,7-(9,9-dioctylfluorene)-alt-5,5-(5',8'-di-2-thienyl-2',3'-diphenylquinoxaline)] (N-P7), was synthesized to achieve a high power conversion efficiency (PCE) of bulk heterojunction (BHJ)-based solar cells. The optical band-gap and highest occupied molecular orbital level of N-P7 were 1.95 and -5.37 eV, respectively. BHJ-based solar cells using N-P7 as a donor and phenyl C71 butyric acid methyl ester as an acceptor gave a PCE as high as 5.5% under AM 1.5G 100 mW/cm2 illumination. We also investigated the effects of substituent groups of quinoxaline-based polymers on the morphology of the BHJ layer.

  6. Analysis of PV modules based on thin film solar cells by dark measurements technique

    Science.gov (United States)

    Agroui, Kamel; Pellegrino, Michelle; Giovanni, Flaminio

    2015-09-01

    The dark measurements technique which were developed to analyze the material properties of solar cells in a PV module and performed either at DC or at AC conditions, can give useful information on the quality of the active material. This technique leads to better understanding the PV module degradation processes, occurring during indoor qualification testing or in real operating conditions. To this purpose an indoor testing laboratory has been set up to detect and monitor the PV modules degradation. A simple technique, based on the analysis of the behaviour of PV devices biased by an AC signal on dark conditions, has been developed to easily and quickly evaluate some parameters like the series, the shunt resistances and the capacitance affecting their electrical characteristics. In the present paper the technique basic concepts will be illustrated. Preliminary experimental results, achieved by applying the technique to some kinds of PV modules based on simple and triple junction's silicon amorphous solar cells, will be presented.

  7. Reliable wet-chemical cleaning of natively oxidized high-efficiency Cu(In,Ga)Se2 thin-film solar cell absorbers

    International Nuclear Information System (INIS)

    Currently, Cu-containing chalcopyrite-based solar cells provide the highest conversion efficiencies among all thin-film photovoltaic (PV) technologies. They have reached efficiency values above 20%, the same performance level as multi-crystalline silicon-wafer technology that dominates the commercial PV market. Chalcopyrite thin-film heterostructures consist of a layer stack with a variety of interfaces between different materials. It is the chalcopyrite/buffer region (forming the p-n junction), which is of crucial importance and therefore frequently investigated using surface and interface science tools, such as photoelectron spectroscopy and scanning probe microscopy. To ensure comparability and validity of the results, a general preparation guide for “realistic” surfaces of polycrystalline chalcopyrite thin films is highly desirable. We present results on wet-chemical cleaning procedures of polycrystalline Cu(In1-xGax)Se2 thin films with an average x?=?[Ga]/([In]?+?[Ga])?=?0.29, which were exposed to ambient conditions for different times. The hence natively oxidized sample surfaces were etched in KCN- or NH3-based aqueous solutions. By x-ray photoelectron spectroscopy, we find that the KCN treatment results in a chemical surface structure which is – apart from a slight change in surface composition – identical to a pristine as-received sample surface. Additionally, we discover a different oxidation behavior of In and Ga, in agreement with thermodynamic reference data, and we find indications for the segregation and removal of copper selenide surface phases from the polycrystalline material

  8. Potential for nanotechnology approaches in the production of crystalline and thin film silicon solar cells.

    Czech Academy of Sciences Publication Activity Database

    Poruba, Aleš; Van??ek, Milan; Ba?inka, R.; ?ech, P.; Wostrý, P.

    Plze? : Západo?eská univerzita v Plzni, 2012 - (Baroch, P.; Kubásek, M.), s. 33-38 ISBN 978-80-261-0133-8. [Potential and Applications of Thin Ceramic and Metal Coatings 2012 (PATCMC 2012). Plze? (CZ), 28.05.2012-30.5.2012] Grant ostatní: FP7(XE) CP-IP 214134-2 Institutional research plan: CEZ:AV0Z10100521 Keywords : EVA foil * tedlar foil * solar cell * silicon Subject RIV: BM - Solid Matter Physics ; Magnetism

  9. Amorphous thin films for solar cell application. Quarterly report No. 2, July 1-September 30, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Jonath, A D; Crowley, J L; MacMillan, H F; Anderson, W W; Junga, F A; Kooi, C F; McNab, T K; Scoble, W R; Thornton, J A

    1979-10-01

    Research on the fabrication of efficient amorphous silicon solar cells is reported. Work on the deposition of a-Si:H films by sputtering is described. Other areas under scrutiny include (a) degree and effect of oxygen and/or argon incorporation into the films, (b) dopant transfer from target to films, (c) dopant and alloy ion-implantation effects, and (d) film annealing behavior. Results to date are presented. (WHK)

  10. Development of a Dense Diffusion Barrier Layer for Thin Film Solar Cells

    OpenAIRE

    Pillay, Sankara

    2009-01-01

    Tantalum diffusion barrier coatings were investigated as a way to improve the conversion efficiency of CIGS (copper indium gallium diselenide) solar cells.  Tantalum coatings were deposited upon silicon and stainless steel foil substrates using direct current magnetron sputtering (DcMS) and high power impulse magnetron sputtering (HiPIMS).  The coatings were characterized using scanning electron microscopy (SEM).  Cross-sectional scanning electron micrographs revealed that the HiPIMS coatings...

  11. Annealing of polycrystalline thin film silicon solar cells in water vapour at sub-atmospheric pressures.

    Czech Academy of Sciences Publication Activity Database

    Pikna, Peter; Pí?, Vlastimil; Benda, V.; Fejfar, Antonín

    2014-01-01

    Ro?. 54, ?. 5 (2014), s. 341-347. ISSN 1210-2709 R&D Projects: GA MŠk 7E10061 Grant ostatní: AV?R(CZ) M100101216; FP7 - POLYSIMODE(XE) 240826 Institutional support: RVO:68378271 Keywords : passivation * water vapour * thin ?lm solar cell * polycrystalline silicon (poly-Si) * multicrys- talline silicon (m-Si) * Suns-VOC Subject RIV: JE - Non-nuclear Energetics, Energy Consumption ; Use

  12. Amorphous silicon thin-film solar cells deposited on flexible substrates using different zinc oxide layers

    Energy Technology Data Exchange (ETDEWEB)

    Alpuim, P.; Samantilleke, A.; Marins, E.; Rebouta, L. [Centro de Fisica, Universidade do Minho, 4800-058 Guimaraes (Portugal); Oliveira, F.; Cerqueira, M.F. [Centro de Fisica, Universidade do Minho, 4800-058 Guimaraes (Portugal); Centro de Fisica, Universidade do Minho, 4710-057 Braga (Portugal); Stefanov, S.; Chiussi, S. [Departamento de Fisica Aplicada, E.T.S.I. Industriales, Universidade de Vigo, Campus Universitario Lagoas Marcosende, 36310 Vigo (Spain); Serra, C. [Departamento de Fisica Aplicada, E.T.S.I. Industriales, Universidade de Vigo, Campus Universitario Lagoas Marcosende, 36310 Vigo (Spain); C.A.C.T.I., Universidade de Vigo, Campus Universitario Lagoas Marcosende, 36310 Vigo (Spain); Bouree, J.E. [Laboratoire de Physique des Interfaces et des Couches Minces, CNRS UMR 7647, Ecole Polytechnique, 91128 Palaiseau (France)

    2010-04-15

    In order to improve the transparent contact layer in amorphous silicon solar cells fabricated on low-temperature plastic substrates, Al and Ga doped ZnO films were deposited at room temperature on plastic and glass and their optical, electronic and structural properties were correlated and optimized. Aiming to explore light trapping effects, plastic substrates were laser textured and their haze and total transmittance and reflectance were compared with those of untextured substrates. Although the haze increased dramatically, from 1.7 to 78.9%, the total transmittance of PET coated with ZnO:Ga decreased from 83.9%, in the untextured substrate, to 58.5% in the textured PET. The haze in reflected light of PET coated with Al increased from 4.3% to 66.2% after texturing but the total reflectance decreased from 70.1% to 36.8%. Therefore the untextured substrates were used in the solar cells. a-Si:H solar cells were deposited at a substrate temperature of 150 C on plastic, in the superstrate p-i-n configuration, and on stainless steel, in the substrate n-i-p configuration. The efficiency is {proportional_to}5% in both types of devices, limited by low J{sub sc} and low fill factor. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  13. Synthesis and Nanostructures of Metal Selenide Precursors for Cu(In,Ga)Se2 Thin-Film Solar Cells.

    Science.gov (United States)

    Cha, Ji-Hyun; Noh, Se Jin; Jung, Duk-Young

    2015-07-20

    A nanoink solution-based process was developed as a low-costing method for the fabrication of Cu(In,Ga)Se2 (CIGSe) thin-film photovoltaic cells. The sonochemical synthesis of CIGSe nanocrystals of the nanoink through step-by-step mixing of the reactants was investigated. To achieve the ideal stoichiometry of Cu(In0.7 Ga0.3 )Se2 to tune the bandgap and to fabricate high-efficiency photovoltaic cells, the synthetic parameters, the concentration of hydrazine, and the amount used of the gallium precursor were investigated. As the hydrazine concentration increased, gallium loss was observed in the CIGSe product. The gallium content in the reactant mixture strongly affected the metal stoichiometry of the prepared CIGSe nanocrystals. The nanoink solution based fabrication of thin-film photovoltaic cells was also explored, and the resulting device showed a conversion efficiency of 5.17?%. PMID:25959012

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

    International Nuclear Information System (INIS)

    In order to meet the increasing demand for electric power generation from solar energy conversion, the development of efficient light absorber materials has been awaited. To this end, the electronic and optical properties of advanced alkaline-earth-metals disilicides and digermanides (SrSi2, BaSi2, SrGe2, and BaGe2) are studied by means of the density functional theory using HSE06 exchange-correlation energy functional. Our calculations show that all these orthorhombic structured compounds have fundamental indirect band gaps in the range Eg ? 0.89–1.25 eV, which is suitable for solar cell applications. The estimated lattice parameters and band gaps are in good agreement with experiments. Our calculations show that the electronic band structures of all four compounds are very similar except in the vicinity of the ?-point. The valence band of these compounds is made up by Si(Ge)-p states, whereas the conduction band is composed of Sr(Ba)-d states. Their band alignments are carefully determined by estimating the work function of each compound using slab model. The optical properties are discussed in terms of the complex dielectric function ?(?)?=??1(?)?+?i?2(?). The static and high-frequency dielectric constants are calculated, taking into account the ionic contribution. The absorption coefficient ?(?) demonstrates that a low energy dispersion of the conduction band, which results in a flat conduction band minimum, leads to large optical activity in these compounds. Therefore, alkaline-earth-metals disilicides and digermanides possess great potential as light absorbers for applications in thin-film solar cell technologies.

  15. Thin-film Organic-based Solar Cells for Space Power

    Science.gov (United States)

    Bailey, Sheila G.; Harris, Jerry D.; Hepp, Aloysius F.; Anglin, Emily J.; Raffaelle, Ryne P.; Clark, Harry R., Jr.; Gardner, Susan T. P.; Sun, Sam S.

    2002-01-01

    Recent advances in dye-sensitized and organic polymer solar cells have lead NASA to investigate the potential of these devices for space power generation. Dye-sensitized solar cells were exposed to simulated low-earth orbit conditions and their performance evaluated. All cells were characterized under simulated air mass zero (AM0) illumination. Complete cells were exposed to pressures less than 1 x 10(exp -7) torr for over a month, with no sign of sealant failure or electrolyte leakage. Cells from Solaronix SA were rapid thermal cycled under simulated low-earth orbit conditions. The cells were cycled 100 times from -80 C to 80 C, which is equivalent to 6 days in orbit. The best cell had a 4.6 percent loss in efficiency as a result of the thermal cycling. In a separate project, novel -Bridge-Donor-Bridge- Acceptor- (-BDBA-) type conjugated block copolymer systems have been synthesized and characterized by photoluminescence (PL). In comparison to pristine donor or acceptor, the PL emissions of final -B-D-B-A- block copolymer films were quenched over 99 percent. Effective and efficient photo induced electron transfer and charge separation occurs due to the interfaces of micro phase separated donor and acceptor blocks. The system is very promising for a variety high efficiency light harvesting applications. Under an SBIR contract, fullerene-doped polymer-based photovoltaic devices were fabricated and characterized. The best devices showed overall power efficiencies of approx. 0.14 percent under white light. Devices fabricated from 2 percent solids content solutions in chlorobenzene gave the best results. Presently, device lifetimes are too short to be practical for space applications.

  16. Spin-coating deposition of PbS and CdS thin films for solar cell application

    Science.gov (United States)

    Patel, Jayesh; Mighri, Frej; Ajji, Abdellah; Tiwari, Devendra; Chaudhuri, Tapas K.

    2014-12-01

    In this work, we describe a simple spin-coating deposition technique for lead sulphide (PbS) and cadmium sulphide (CdS) films from a methanolic metal-thiourea complex. The characterization of the films by X-ray diffraction and X-ray photoelectron spectroscopy techniques revealed that pure cubic phase PbS and CdS layers were formed via this method. As shown by atomic force microscopy and scanning electron microscopy results, both films were homogeneous and presented a smooth surface. Optical properties showed that the energy band gap of PbS and CdS films were around 1.65 and 2.5 eV, respectively. The PbS film is p-type in nature with an electrical conductivity of around 0.8 S/cm. The hole concentration and mobility were 2.35 × 1018 cm-3 and 2.16 × 10-3 cm2/V/s, respectively, as determined from Hall measurement. Both films were used to develop a thin film solar cell device of graphite/PbS/CdS/ITO/glass. Device characterization showed the power conversion efficiency of around 0.24 %. The corresponding open circuit voltage, short circuit current and fill factor were 0.570 V, 1.32 mA/cm2 and 0.32, respectively.

  17. Spin-coating deposition of PbS and CdS thin films for solar cell application

    International Nuclear Information System (INIS)

    In this work, we describe a simple spin-coating deposition technique for lead sulphide (PbS) and cadmium sulphide (CdS) films from a methanolic metal-thiourea complex. The characterization of the films by X-ray diffraction and X-ray photoelectron spectroscopy techniques revealed that pure cubic phase PbS and CdS layers were formed via this method. As shown by atomic force microscopy and scanning electron microscopy results, both films were homogeneous and presented a smooth surface. Optical properties showed that the energy band gap of PbS and CdS films were around 1.65 and 2.5 eV, respectively. The PbS film is p-type in nature with an electrical conductivity of around 0.8 S/cm. The hole concentration and mobility were 2.35 x 1018 cm-3 and 2.16 x 10-3 cm2/V/s, respectively, as determined from Hall measurement. Both films were used to develop a thin film solar cell device of graphite/PbS/CdS/ITO/glass. Device characterization showed the power conversion efficiency of around 0.24 %. The corresponding open circuit voltage, short circuit current and fill factor were 0.570 V, 1.32 mA/cm2 and 0.32, respectively. (orig.)

  18. Controlled growth of Cu2ZnSnS4 (CZTS) thin films for heterojunction solar-cell applications

    International Nuclear Information System (INIS)

    Cu2ZnSnS4 (CZTS) thin films (absorber layers) were successfully synthesized on glass substrates by using a RF magnetron sputtering system. The films were rapidly thermally annealed in a nitrogen atmosphere for 20 minutes to improve the crytallinity. The formation of kesterite structures (JCPDS-26-0575) in the film was confirmed using X-ray diffraction (XRD) measurements. The improved crytallinity of the CZTS with a (112) orientation was observed with increasing annealing temperature. The band gaps of all the as-deposited and annealed films were found to be in the range from 1.97 to 1.55 eV. The films' stoichiometry and morphologies were investigated using scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDAX) measurements. The sample annealed at 500 .deg. C showed a uniform granular structure with an elemental composition near stoichiometric CZTS. Next, a buffer layer of ZnS for a heterojuntion solar cell was fabricated using a chemical bath deposition (CBD) technique. The films adhered well, were optically transparent and had band gap energy of 3.6 eV.

  19. Study of alternative back contacts for thin film Cu2ZnSnSe4-based solar cells

    Science.gov (United States)

    Oueslati, Souhaib; Brammertz, Guy; Buffière, Marie; ElAnzeery, Hossam; Mangin, Denis; ElDaif, Ounsi; Touayar, Oualid; Köble, Christine; Meuris, Marc; Poortmans, Jef

    2015-01-01

    Cu2ZnSnSe4 thin film solar cells are usually fabricated on a soda lime glass substrate with a molybdenum (Mo) back contact. It is suspected that degradation in electrical performance occurs due to the formation of a barrier between the absorber and Mo back contact. To overcome such degradation, Titanium Nitride (TiN), Titanium Tungsten (TiW), Chromium (Cr), Titanium (Ti) and Aluminum (Al) deposited on Mo-coated glass substrates are investigated as alternative back contact materials. Physical and electrical characterization as well as photoluminescence measurements are performed. Compositional analysis of the absorber layer on the metallized substrates identifies Mo, TiN and TiW as being the most inert during the formation of Cu2ZnSnSe4. On the other hand, Ti and Cr reacted with Se during selenization, thereby affecting the growth of the absorber, leading to low conversion efficiency. For Al, the absorber layer was etched after the standard potassium cyanide etch, hence, cannot be used as a back contact. The best device efficiencies obtained are 8.8% on TiN, 7.5% on Mo and 5.9% on TiW, respectively. The TiN back contact provides the lowest barrier value of about 15?meV which could be considered as a good ohmic contact.

  20. Study of alternative back contacts for thin film Cu2ZnSnSe4-based solar cells

    International Nuclear Information System (INIS)

    Cu2ZnSnSe4 thin film solar cells are usually fabricated on a soda lime glass substrate with a molybdenum (Mo) back contact. It is suspected that degradation in electrical performance occurs due to the formation of a barrier between the absorber and Mo back contact. To overcome such degradation, Titanium Nitride (TiN), Titanium Tungsten (TiW), Chromium (Cr), Titanium (Ti) and Aluminum (Al) deposited on Mo-coated glass substrates are investigated as alternative back contact materials. Physical and electrical characterization as well as photoluminescence measurements are performed. Compositional analysis of the absorber layer on the metallized substrates identifies Mo, TiN and TiW as being the most inert during the formation of Cu2ZnSnSe4. On the other hand, Ti and Cr reacted with Se during selenization, thereby affecting the growth of the absorber, leading to low conversion efficiency. For Al, the absorber layer was etched after the standard potassium cyanide etch, hence, cannot be used as a back contact. The best device efficiencies obtained are 8.8% on TiN, 7.5% on Mo and 5.9% on TiW, respectively. The TiN back contact provides the lowest barrier value of about 15?meV which could be considered as a good ohmic contact. (paper)

  1. Rapid thermal annealing of sputter-deposited ZnO:Al films for microcrystalline Si thin-film solar cells

    Directory of Open Access Journals (Sweden)

    Hanajiri T.

    2012-06-01

    Full Text Available Rapid thermal annealing of sputter-deposited ZnO and Al-doped ZnO (AZO films with and without an amorphous silicon (a-Si capping layer was investigated using a radio-frequency (rf argon thermal plasma jet of argon at atmospheric pressure. The resistivity of bare ZnO films on glass decreased from 108 to 104–105 ??cm at maximum surface temperatures Tmaxs above 650 °C, whereas the resistivity increased from 10-4 to 10-3–10-2??cm for bare AZO films. On the other hand, the resistivity of AZO films with a 30-nm-thick a-Si capping layer remained below 10-4??cm, even after TPJ annealing at a Tmax of 825 °C. The film crystallization of both AZO and a-Si layers was promoted without the formation of an intermixing layer. Additionally, the crystallization of phosphorous- and boron-doped a-Si layers at the sample surface was promoted, compared to that of intrinsic a-Si under the identical plasma annealing conditions. The TPJ annealing of n+-a-Si/textured AZO was applied for single junction n-i-p microcrystalline Si thin-film solar cells.

  2. Controlled growth of Cu2ZnSnS4 (CZTS) thin films for heterojunction solar-cell applications

    Science.gov (United States)

    Inamdar, A. I.; Jeon, Ki-Young; Woo, Hyeon Seok; Jung, Woong; Im, Hyunsik; Kim, Hyungsang

    2012-05-01

    Cu2ZnSnS4 (CZTS) thin films (absorber layers) were successfully synthesized on glass substrates by using a RF magnetron sputtering system. The films were rapidly thermally annealed in a nitrogen atmosphere for 20 minutes to improve the crytallinity. The formation of kesterite structures (JCPDS-26-0575) in the film was confirmed using X-ray diffraction (XRD) measurements. The improved crytallinity of the CZTS with a (112) orientation was observed with increasing annealing temperature. The band gaps of all the as-deposited and annealed films were found to be in the range from 1.97 to 1.55 eV. The films' stoichiometry and morphologies were investigated using scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDAX) measurements. The sample annealed at 500 °C showed a uniform granular structure with an elemental composition near stoichiometric CZTS. Next, a buffer layer of ZnS for a heterojuntion solar cell was fabricated using a chemical bath deposition (CBD) technique. The films adhered well, were optically transparent and had band gap energy of 3.6 eV.

  3. Electrical properties of grain boundaries in Cu(In,Ga)(S,Se)2 thin films for solar cells

    International Nuclear Information System (INIS)

    Electron-beam-induced current (EBIC) and electron backscatter diffraction (EBSD) in a scanning electron microscope are powerful tools to investigate the electrical and microstructural properties of grains and grain boundaries in Cu(In,Ga)(S,Se)2 absorber layers in thin-film solar cells. For the present investigation, the Mo/glass stack was stripped off the remaining Cu(In,Ga)(S,Se)2/CdS/ZnO heterojunction, in order to prepare a Cu(In,Ga)(S,Se)2 surface with reduced roughness, leading to both, high-quality EBSD patterns and decreased number of topography artefacts in EBIC distribution images. In comparison to EBIC analyses on cross-section samples, the measurements on back-surfaces increase the number of accessible grain boundaries and therefore improve the statistics of their electrical properties. EBSD maps identify clearly the positions of the grain boundaries as well as allow for their classifications. Across various grain boundaries, profiles were extracted from EBIC distribution images. Corresponding simulation of these profiles provide values for minority-carrier diffusion lengths and recombination velocities at grain boundaries. The general result for Cu(In,Ga)Se2 layers with various In/Ga ratios as well as Cu concentrations is a similar collection at grain interiors and ?3 grain boundaries and a reduced charge-carrier collection at non-?3 grain boundaries.

  4. Ultraviolet laser ablation of fluorine-doped tin oxide thin films for dye-sensitized back-contact solar cells

    International Nuclear Information System (INIS)

    In this study, laser ablation of a fluorine-doped tin oxide (FTO) thin film on a glass substrate was conducted using a 355 nm Nd:YVO4 ultraviolet (UV) laser to obtain a 4 × 4 mm microstructure. The microstructure contains a symmetric set of interdigitated FTO finger electrodes of a monolithic back-contact dye-sensitized solar cell (BC-DSC) on a common substrate. The effects of UV laser ablation parameters (such as laser fluence, repetition frequency, and scanning speed) on the size precision and quality of the microstructure were investigated using a 4 × 4 orthogonal design and an assistant experimental design. The incident photon-to-electron conversion efficiency and the current–voltage characteristics of the BC-DSC base of the interdigitated FTO finger electrodes were also determined. The experimental results show that an FTO film microstructure with high precision and good quality can be produced on a glass substrate via laser ablation with high scanning speed, high repetition frequency, and appropriate laser fluence. - Highlights: ? The ablation width and depth generally depend on the laser fluence. ? The scanning speed and the repetition frequency must match each other. ? Slight ablation of the glass substrate can completely remove F-doped tin oxide

  5. Spin-coating deposition of PbS and CdS thin films for solar cell application

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Jayesh; Mighri, Frej [Laval University, CREPEC, Department of Chemical Engineering, Quebec, QC (Canada); Ajji, Abdellah [Ecole Polytechnique, CREPEC, Chemical Engineering Department, Montreal, QC (Canada); Tiwari, Devendra; Chaudhuri, Tapas K. [Charotar University of Science and Technology (CHARUSAT), Dr. K.C. Patel Research and Development Centre, Anand District, Gujarat (India)

    2014-12-15

    In this work, we describe a simple spin-coating deposition technique for lead sulphide (PbS) and cadmium sulphide (CdS) films from a methanolic metal-thiourea complex. The characterization of the films by X-ray diffraction and X-ray photoelectron spectroscopy techniques revealed that pure cubic phase PbS and CdS layers were formed via this method. As shown by atomic force microscopy and scanning electron microscopy results, both films were homogeneous and presented a smooth surface. Optical properties showed that the energy band gap of PbS and CdS films were around 1.65 and 2.5 eV, respectively. The PbS film is p-type in nature with an electrical conductivity of around 0.8 S/cm. The hole concentration and mobility were 2.35 x 10{sup 18} cm{sup -3} and 2.16 x 10{sup -3} cm{sup 2}/V/s, respectively, as determined from Hall measurement. Both films were used to develop a thin film solar cell device of graphite/PbS/CdS/ITO/glass. Device characterization showed the power conversion efficiency of around 0.24 %. The corresponding open circuit voltage, short circuit current and fill factor were 0.570 V, 1.32 mA/cm{sup 2} and 0.32, respectively. (orig.)

  6. Numerical simulation of grain boundary effects in Cu(In,Ga)Se{sub 2} thin-film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Taretto, K. [Departamento de Electrotecnia, Facultad de Ingenieria, Universidad Nacional del Comahue, Buenos Aires 1400, 8300 Neuquen (Argentina); Rau, U. [Institute of Physical Electronics, University of Stuttgart, Pfaffenwaldring 47, 70569 Stuttgart (Germany)]. E-mail: uwe.rau@ipe.uni-stuttgart.de; Werner, J.H. [Institute of Physical Electronics, University of Stuttgart, Pfaffenwaldring 47, 70569 Stuttgart (Germany)

    2005-06-01

    Two-dimensional numerical simulations of polycrystalline Cu(In,Ga)Se{sub 2} thin-film solar cells show that grain boundary (GB) recombination can deteriorate the photovoltaic power conversion efficiency of these devices by about 9% absolute with respect to a starting value of 21.7% that would hold for a material without GBs. The achieved record efficiencies of 19% are only possible if the recombination velocity S at GBs is kept below S=10{sup 3} cm s{sup -1}. Comparing devices that have all defects homogeneously distributed in the bulk to devices where the same number of defects is concentrated at GBs only unveils that the latter situation is more favorable because of kinetic restrictions. The efficiency difference between the homogeneous and the concentrated cases is, however, only 1% (absolute). We further model the possible effect of an additional hole barrier at the GB by assuming asymmetric capture cross-sections for electrons and holes. We find that the positive consequence of this feature is rather limited and much dependent on the specific properties of the GB defects. For example, the efficiency improves by 2% when introducing a hole barrier of 120 meV at a GB with midgap defects. The same improvement would result from a reduction of the GB defects by a factor of 2.5.

  7. Influences of thickness-uniformity and surface morphology on the electrical and optical properties of sputtered CdTe thin films for large-area II-VI semiconductor heterostructured solar cells

    International Nuclear Information System (INIS)

    It is well known that, theoretically, thin-film cadmium telluride (CdTe) solar cell technology can improve on the conversion efficiency and production costs of conventional silicon solar cell technology. Due to the optimal band gap energy (about 1.4 eV) for solar energy absorption, high light absorption capability and lower cost requirements for solar cell production, CdTe has been widely researched as being suitable for commercial cell production. In this study, the sputtering method, which can improve on the cost-efficiency and mass-production of solar cells, was employed to deposit the CdTe thin film with various processing conditions such as sputtering power, and gas pressure. The effects of the processing conditions on the thickness-uniformity and surface morphology of the CdTe thin films were investigated using atomic force microscope (AFM) and ellipsometry for large-area solar cells. The photovoltaic properties of CdTe thin films were analyzed in relation to the different thickness-uniformity and surface morphology caused by the various process conditions. The thickness-uniformity, which was controlled by the process conditions in the sputtering process, was found to affect the photovoltaic properties of the sputtering-deposited CdTe thin films. Higher carrier concentration and better optical absorbance were obtained in CdTe thin films with a good thickness-uniformity.

  8. Q-switched all-solid-state lasers and application in processing of thin-film solar cell

    Science.gov (United States)

    Liu, Liangqing; Wang, Feng

    2009-08-01

    Societal pressure to renewable clean energy is increasing which is expected to be used as part of an overall strategy to address global warming and oil crisis. Photovoltaic energy conversion devices are on a rapidly accelerating growth path driven by government, of which the costs and prices lower continuously. The next generation thin-film devices are considered to be more efficiency and greatly reduced silicon consumption, resulting in dramatically lower per unit fabrication costs. A key aspect of these devices is patterning large panels to create a monolithic array of series-interconnected cells to form a low current, high voltage module. This patterning is accomplished in three critical scribing processes called P1, P2, and P3. All-solid-state Q-switched lasers are the technology of choice for these processes, due to their advantages of compact configuration, high peak-value power, high repeat rate, excellent beam quality and stability, delivering the desired combination of high throughput and narrow, clean scribes. The end pumped all-solid-state lasers could achieve 1064nm IR resources with pulse width of nanoseconds adopting acoustic-optics Q-switch, shorter than 20ns. The repeat rate is up to 100kHz and the beam quality is close to diffraction limit. Based on this, 532nm green lasers, 355nm UV lasers and 266nm DUV lasers could be carried out through nonlinear frequency conversion. Different wave length lasers are chose to process selective materials. For example, 8-15 W IR lasers are used to scribe the TCO film (P1); 1-5 W green lasers are suitable for scribing the active semiconductor layers (P2) and the back contact layers (P3). Our company, Wuhan Lingyun Photo-electronic System Co. Ltd, has developed 20W IR and 5W green end-pumped Q-switched all-solid-state lasers for thin-film solar industry. Operating in high repeat rates, the speed of processing is up to 2.0 m/s.

  9. Reactive sputtering of precursors for Cu2ZnSnS4 thin film solar cells

    OpenAIRE

    Ericson, Tove; Kubart, Tomas; Scragg, Jonathan J.; Platzer-Björkman, Charlotte

    2012-01-01

    The quaternary semiconductor Cu2ZnSnS4 (CZTS) is a possible In-free replacement for Cu(In,Ga)Se-2. Here we present reactive sputtering with the possibility to obtain homogeneous CZTS-precursors with tunable composition and a stoichiometric quantity of sulfur. The precursors can be rapidly annealed to create large grained films to be used in solar cells. The reactive sputtering process is flexible, and morphology, stress and metal and sulfur contents were varied by changing the H2S/Ar-flow rat...

  10. Thin film silicon solar cells on upgraded metallurgical silicon substrates prepared by liquid phase epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Peter, K.; Kopecek, R.; Fath, P.; Bucher, E. [University of Konstanz (Germany). Dept. of Physics; Zahedi, C. [Elkem Solar, Oslo (Norway)

    2002-10-01

    Thin layers of about 30 {mu}m thickness were grown on upgraded metallurgical (UMG) silicon substrates by liquid phase epitaxy (LPE) from an indium solvent. Instead of adding electronic grade silicon to the solution, a melt back step was carried out before each growth process to supply silicon to the melt from the UMG-Si wafers. We present an LPE technology which is capable to be directly scaled up to a few hundred layers per run. Solar cells have been fabricated based on phosphorous paste diffusion with efficiencies up to {eta}=10.0%. (Author)

  11. Synthesis and characterization of CIS nanoparticle ink for low-cost thin film solar cells.

    Science.gov (United States)

    Shim, Joongpyo; Hahn, Jae-Sub; Lee, Soo-Ho; Lee, Jaehyeong

    2014-12-01

    CuSe and CuInSe2 nanoparticles were synthesized through the aqueous solution process using NaBH4 solution as a solvent and subsequent heat-treatment. Not only the synthesized nanoparticles, CuSe and CuInSe2, but also spray-coated thin films prepared by using CuSe and CuInSe2 were characterized by XRD, SEM-EDS, TGA and UV-Vis spectroscopy. CuSe nanoparticles with a plate-like shape, which were confirmed by XRD and SEM, were directly prepared by a reaction of a mixture of CuCl2 and Se in the aqueous solution of NaBH4 at room temperature. Cu-In-Se compounds were obtained through the reaction of CuCl2, InCl3, and Se in the aqueous solution of NaBH4, were consisted of the mixture of CuSe(x) and In hydroxides, and were transformed into CuInSe2 with a chalcopyrite structure by a heat-treatment at 300 degrees C. PMID:25971051

  12. Heteroepitaxial Cu2O thin film solar cell on metallic substrates.

    Science.gov (United States)

    Wee, Sung Hun; Huang, Po-Shun; Lee, Jung-Kun; Goyal, Amit

    2015-01-01

    Heteroepitaxial, single-crystal-like Cu2O films on inexpensive, flexible, metallic substrates can potentially be used as absorber layers for fabrication of low-cost, high-performance, non-toxic, earth-abundant solar cells. Here, we report epitaxial growth of Cu2O films on low cost, flexible, textured metallic substrates. Cu2O films were deposited on the metallic templates via pulsed laser deposition under various processing conditions to study the influence of processing parameters on the structural and electronic properties of the films. It is found that pure, epitaxial Cu2O phase without any trace of CuO phase is only formed in a limited deposition window of P(O2) - temperature. The (00l) single-oriented, highly textured, Cu2O films deposited under optimum P(O2) - temperature conditions exhibit excellent electronic properties with carrier mobility in the range of 40-60?cm(2)?V(-1)?s(-1) and carrier concentration over 10(16)?cm(-3). The power conversion efficiency of 1.65% is demonstrated from a proof-of-concept Cu2O solar cell based on epitaxial Cu2O film prepared on the textured metal substrate. PMID:26541499

  13. A study of nanoellipsoids for thin-film plasmonic solar cell applications

    International Nuclear Information System (INIS)

    Metal nanoparticles (MNPs) support surface plasmon modes, which are used to couple light into the underlying optical modes of a semiconductor. In this paper, we investigate the suitability of localized surface plasmons to enhance the scattering efficiency of incident light from a silver nanoellipsoid and hence its absorption into silicon solar cells. Light scattering efficiency of the silver nanoellipsoid was calculated based on a quasi-static approximation. We found that the silver nanoellipsoid may be tuned to have higher scattering efficiency in the near infrared region. In this work the particle size, shape, aspect ratio and the distance of the nanoellipsoid from the substrate were varied to study their impact on light trapping in solar cells. We found that the nanoellipsoid (oblate) is more suitable to tune the resonance near the band gap of silicon as compared with a nanosphere. Calculations show that the desired resonance (around 1000 nm) can be achieved with aspect ratio lying in the domain 0.3-0.4 with a particle size of 15 nm and distance between substrate and nanoellipsoid of around 2-3 nm. (paper)

  14. Titanium dioxide thin films prepared by electrolysis from aqueous solution of titanium–lactic acid complex for dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Titanium oxide (TiOx) thin films were prepared on transparent conducting substrate (fluorine-doped tin oxide) by cathodic electrolysis of a solution containing a titanium bis(ammonium lactato)dihydroxide and an ammonium nitrate at 323 K. Post-deposition treatment: calcination at 723 K or hot-water treatment at > 363 K promoted the growth of an anatase type crystalline phase in the TiO2 thin film, as evidenced by X-ray diffraction and X-ray photoelectron spectroscopy. The calcined films were used as electrodes of a dye-sensitized solar cells and the cells' energy conversion efficiency was comparable to that obtained with commercially available TiO2 nanoparticle electrodes.

  15. 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 ?m absorber layer and CdS layer 0.05 ?m, ZnO layer 0.1 ?m, 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.

  16. Promises of Cu (In, GaSe2 Thin Film Solar Cells from the Perspective of Material Properties, Fabrication Methods and Current Research Challenges

    Directory of Open Access Journals (Sweden)

    Nowshad Amin

    2011-01-01

    Full Text Available Solar Photovoltaic (PV technologies are undoubtedly going to merge with mainstream energy harvesting technologies for mankind around the globe in near future. The promises that various photovoltaic options provide to date include high conversion efficiency with low manufacturing cost. Solar manufacturing industries are in the midst of an argument over which material to dominate the future for harvesting sunlight. Solar panels based on silicon currently account for more than 90% of the production with some limitations. However, much attention has been paid to alternatives like thin film semiconductor materials such as amorphous silicon, cadmium telluride and copper-indium-gallium-diselenide based solar cells due to the promises in cost efficiency. Attributed to some recent breakthrough in copper-indium-gallium-diselenide (CIS, thereafter based solar cell efficiency, commercialization has got momentum around the world. Here, progresses in Cu (In, Ga Se2 thin film solar cells technologies are discussed here in regard to material properties of the Cu (In, Ga Se2 absorber layer, fabrication method of the complete device and the current CIGS research challenges. The scope of this review aims to elucidate the basics of CIGS solar cells fabricated by co-evaporation method which yields the highest conversion efficiency so far.

  17. Structural and Optical Properties of ZnO Thin Films for Dye-Sensitized Solar Cell

    Directory of Open Access Journals (Sweden)

    H. Abdullah

    2014-01-01

    Full Text Available The zinc oxide sol-gel was prepared as follows: Zinc acetate (M183.46. Zn(C2H3O22, 99.99% chemical purity was first dissolved in iso propanol ((CH32CHOH at room temperature. By using this method, the formation of zinc oxide film is much easier and cheaper to be prepared and it has been shown to achieve high breakdown fields by small grain size. Characterization of the zinc oxide is needed by using X-ray Diffraction (XRD, Scanning Electron Microscope (SEM and Ultraviolet-Visible Spectroscopy (UV-Vis. XRD pattern shows the deposited films were polycrystalline with a hexagonal wurzite structure. Effect in concentration and thickness of zinc oxide will differ in the bandgap of the semiconductor. By doing this research, it is believe that zinc oxide has many advantages in solar cell application.

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

    Science.gov (United States)

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

    2015-01-01

    Solution-processed metal halide perovskite semiconductors, such as CH3NH3PbI3, have exhibited remarkable performance in solar cells, despite having non-negligible density of defect states. A likely candidate is halide vacancies within the perovskite crystals, or the presence of metallic lead, both generated due to the imbalanced I/Pb stoichiometry which could evolve during crystallization. Herein, we show that the addition of hypophosphorous acid (HPA) in the precursor solution can significantly improve the film quality, both electronically and topologically, and enhance the photoluminescence intensity, which leads to more efficient and reproducible photovoltaic devices. We demonstrate that the HPA can reduce the oxidized I2 back into I?, and our results indicate that this facilitates an improved stoichiometry in the perovskite crystal and a reduced density of metallic lead. PMID:26615763

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

    Energy Technology Data Exchange (ETDEWEB)

    Trefny, J.U.; Mao, D. [Colorado School of Mines, Golden, CO (United States). Dept. of Physics

    1998-01-01

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

  20. Tuning of undoped ZnO thin film via plasma enhanced atomic layer deposition and its application for an inverted polymer solar cell

    Directory of Open Access Journals (Sweden)

    Mi-jin Jin

    2013-10-01

    Full Text Available We studied the tuning of structural and optical properties of ZnO thin film and its correlation to the efficiency of inverted solar cell using plasma-enhanced atomic layer deposition (PEALD. The sequential injection of DEZn and O2 plasma was employed for the plasma-enhanced atomic layer deposition of ZnO thin film. As the growth temperature of ZnO film was increased from 100?°C to 300?°C, the crystallinity of ZnO film was improved from amorphous to highly ordered (002 direction ploy-crystal due to self crystallization. Increasing oxygen plasma time in PEALD process also introduces growing of hexagonal wurtzite phase of ZnO nanocrystal. Excess of oxygen plasma time induces enhanced deep level emission band (500 ? 700 nm in photoluminescence due to Zn vacancies and other defects. The evolution of structural and optical properties of PEALD ZnO films also involves in change of electrical conductivity by 3 orders of magnitude. The highly tunable PEALD ZnO thin films were employed as the electron conductive layers in inverted polymer solar cells. Our study indicates that both structural and optical properties rather than electrical conductivities of ZnO films play more important role for the effective charge collection in photovoltaic device operation. The ability to tune the materials properties of undoped ZnO films via PEALD should extend their functionality over the wide range of advanced electronic applications.

  1. Transmission Electron Microscopy of the Textured Silver Back Reflector of a Thin Film Silicon Solar Cell: From Crystallography to Optical Absorption

    DEFF Research Database (Denmark)

    Duchamp, Martial; Söderström, K.

    2011-01-01

    The study of light trapping in amorphous, microcrystalline and micromorph thin-film Si solar cells is an important and active field of investigation. It has been demonstrated that the use of a rough Ag back-reflector lead to an increase of short circuit current but also to losses through the creation of surface plasmon polaritons. Here, we use transmission electron microscopy (TEM) techniques to study the grain structure of a Ag thin-film that was sputtered on top of 2-?m-thick rough ZnO layer - defects, such as twin-boundaries have been observed. A smoothing of the top Ag surface was also observed after ex-situ annealing. Electron energy-loss spectroscopy with a monochromatic beam was used to measure the surface plasmon resonance with nm spatial resolution. 1 eV and 3 eV Ag surface plasmon resonances have been observed on as-grown layers. Such measurements provide valuable information about the origin of optical absorption losses previously measured in Ag back-reflector of thin-film Si solar cells.

  2. Thin-Film Solid Oxide Fuel Cells

    Science.gov (United States)

    Chen, Xin; Wu, Nai-Juan; Ignatiev, Alex

    2009-01-01

    The development of thin-film solid oxide fuel cells (TFSOFCs) and a method of fabricating them have progressed to the prototype stage. This can result in the reduction of mass, volume, and the cost of materials for a given power level.

  3. Chemical Vapor Deposition for Ultra-lightweight Thin-film Solar Arrays for Space

    Science.gov (United States)

    Hepp, Aloysius F.; Raffaelle, Ryne P.; Banger, Kulbinder K.; Jin, Michael H.; Lau, Janice E.; Harris, Jerry D.; Cowen, Jonathan E.; Duraj, Stan A.

    2002-01-01

    The development of thin-film solar cells on flexible, lightweight, space-qualified substrates provides an attractive cost solution to fabricating solar arrays with high specific power, (W/kg). The use of a polycrystalline chalcopyrite absorber layer for thin film solar cells is considered as the next generation photovoltaic devices. A key technical issues outlined in the 2001 U.S. Photovoltaic Roadmap, is the need to develop low cost, high throughput manufacturing for high-efficiency thin film solar cells. At NASA GRC we have focused on the development of new single-source-precursors (SSPs) and their utility to deposit the chalcopyrite semi-conducting layer (CIS) onto flexible substrates for solar cell fabrication. The syntheses and thermal modulation of SSPs via molecular engineering is described. Thin-film fabrication studies demonstrate the SSPs can be used in a spray CVD process, for depositing CIS at reduced temperatures, which display good electrical properties, suitable for PV devices.

  4. Polymer and organic solar cells viewed as thin film technologies: What it will take for them to become a success outside academia

    DEFF Research Database (Denmark)

    Krebs, Frederik C; JØrgensen, Mikkel

    2013-01-01

    The polymer and organic solar cell technology is critically presented in the context of other thin film technologies with a specific focus on what it will take to make them a commercial success. The academic success of polymer and organic solar cells far outweigh any other solar cell technology when judging by the number of scientific publications whereas the application of polymer and organic solar cells in real products is completely lacking. This aspect is viewed as a sign of the polymer and organic solar cell field as being more complex and less mature and it raises the question of whether an organic analog to a successful inorganic technology is forcibly needed and indeed whether it is at all worth exploring beyond academia.

  5. Improved photocurrent of a poly (3,4-ethylenedioxythiophene)-ClO??/TiO? thin film-modified counter electrode for dye-sensitized solar cells.

    Science.gov (United States)

    Sakurai, Sho; Kawamata, Yuka; Takahashi, Masashi; Kobayashi, Koichi

    2011-01-01

    We prepared a poly(3,4-ethylenedioxythiophene) (PEDOT)-ClO??-supported TiO? thin-film electrode as a counter electrode on a transparent conductive oxide glass electrode for a dye-sensitized solar cell (DSSC) using a combination of sol-gel and electropolymerization methods. The photocurrent-voltage characteristics indicate that DSSCs with PEDOT-ClO??/TiO? thin-film counter electrodes had a high photovoltaic conversion efficiency similar to that of PEDOT-ClO??/TiO? particle composite-film electrodes. Furthermore, it was found that the photocurrent was increased by attaching a reflector to the opposite side of the transparent counter electrode. PMID:22123245

  6. Preparation of Cu{sub 2}ZnSnS{sub 4} thin film solar cells under non-vacuum condition

    Energy Technology Data Exchange (ETDEWEB)

    Moritake, Noriko; Fukui, Yuki; Oonuki, Masatoshi; Tanaka, Kunihiko; Uchiki, Hisao [Department of Electrical Engineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188 (Japan)

    2009-05-15

    Cu{sub 2}ZnSnS{sub 4} (CZTS) thin film solar cells have been fabricated with the all semiconductor layers prepared under non-vacuum conditions. For the solar cell structure of Al/ZnO:Al/CdS/CZTS/Mo/Soda Lime Glass (SLG) substrate, ZnO:Al window, CdS buffer and CZTS absorber layers were deposited by sol-gel, chemical bath deposition (CBD) and sol-gel sulfurizing methods, respectively. Since the CdS buffer layer plays an important role in the final photovoltaic properties of thin film solar cells, an optimum condition of the CdS deposition was first determined. As a result of the investigations, the best solar cell showed an open circuit voltage of 554 mV, a short current density of 6.70 mA/cm{sup 2}, a fill factor of 43.4% and a conversion efficiency of 1.61%. This is the highest conversion efficiency to date of the CZTS solar cell prepared under non-vacuum conditions. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  7. Chemical bath deposition of thin semiconductor films for use as buffer layers in CuInS sub 2 thin film solar cells

    CERN Document Server

    Kaufmann, C A

    2002-01-01

    different growth phases, layer morphology and solar cell performance were sought and an improved deposition process was developed. As a result, Cd-free CulnS sub 2 thin film solar cells with efficiencies of up to 10.6%) (total area) could be produced. Overall the substitution of CdS is shown to be possible by different alternative compounds, such as Zn(OH,O) sub x S sub y or In(OH,O) sub x S sub y. In the case of In(OH,O) sub x S sub y , an understanding of the CBD process and the effect of different growth phases on the resulting solar cell characteristics could be developed. A CulnS sub 2 thin film solar cell is a multilayered semiconductor device. The solar cells discussed have a layer sequence Mo/CulnS sub 2 /buffer/i-ZnO/ZnO:Ga, where a heterojunction establishes between the p-type absorber and the n-type front contact. Conventionally the buffer consists of CdS, deposited by chemical bath deposition (CBD). Apart from providing process oriented benefits the buffer layer functions as a tool for engineering...

  8. Intragrain defects in polycrystalline silicon layers grown by aluminum-induced crystallization and epitaxy for thin-film solar cells

    Science.gov (United States)

    Van Gestel, Dries; Gordon, Ivan; Bender, Hugo; Saurel, Damien; Vanacken, Johan; Beaucarne, Guy; Poortmans, Jef

    2009-06-01

    Polycrystalline silicon (pc-Si) thin-films with a grain size in the range of 0.1-100 ?m grown on top of inexpensive substrates are economical materials for semiconductor devices such as transistors and solar cells and attract much attention nowadays. For pc-Si, grain size enlargement is thought to be an important parameter to improve material quality and therefore device performance. Aluminum-induced crystallization (AIC) of amorphous Si in combination with epitaxial growth allows achieving large-grained pc-Si layers on nonsilicon substrates. In this work, we made pc-Si layers with variable grain sizes by changing the crystallization temperature of the AIC process in order to see if larger grains indeed result in better solar cells. Solar cells based on these layers show a performance independent of the grain size. Defect etching and electron beam induced current (EBIC) measurements showed the presence of a high density of electrically active intragrain defects. We therefore consider them as the reason for the grain size independent device performance. Besides dislocations and stacking faults, also ?3 boundaries were electrically active as shown by combining electron backscattered diffraction with EBIC measurements. The electrical activity of the defects is probably triggered by impurity decoration. Plasma hydrogenation changed the electrical behavior of the defects, as seen by photoluminescence, but the defects were not completely passivated as shown by EBIC measurements. In order to reveal the origin of the defects, cross section transmission electron microscopy measurements were done showing that the intragrain defects are already present in the AIC seed layer and get copied into the epitaxial layer during epitaxial growth. The same types of intragrain defects were found in layers made on different substrates (alumina ceramic, glass ceramic, and oxidized silicon wafer) from which we conclude that intragrain defects are not related to the relatively rough alumina ceramic substrates often used in combination with high temperature epitaxy. Further improvement of the material quality, and hence device performance, is therefore not simply achieved by increasing the grain size, but the intragrain quality of the material also needs to be taken into account. For pc-Si layers based on AIC and epitaxial growth, the seed layer has a crucial impact on the intragrain defect formation.

  9. Properties of double-layered Ga-doped Al-zinc-oxide/titanium-doped indium-tin-oxide thin films prepared by dc magnetron sputtering applied for Si-based thin film solar cells

    International Nuclear Information System (INIS)

    In this article, Ga-doped Al-zinc-oxide (GAZO)/titanium-doped indium-tin-oxide (ITIO) bi-layer films were deposited onto glass substrates by direct current (dc) magnetron sputtering. The bottom ITIO film, with a thickness of 200 nm, was sputtered onto the glass substrate. The ITIO film was post-annealed at 350 deg. C for 10-120 min as a seed layer. The effect of post-annealing conditions on the morphologies, electrical, and optical properties of ITIO films was investigated. A GAZO layer with a thickness of 1200 nm was continuously sputtered onto the ITIO bottom layer. The results show that the properties of the GAZO/ITIO films were strongly dependent on the post-annealed conditions. The spectral haze (Tdiffuse/Ttotal) of the GAZO/ITIO bi-layer films increases upon increasing the post-annealing time. The haze and resistivity of the GAZO/ITIO bi-layer films were improved with the post-annealed process. After optimizing the deposition and annealing parameters, the GAZO/ITIO bi-layer film has an average transmittance of 83.20% at the 400-800 nm wavelengths, a maximum haze of 16%, and the lowest resistivity of 1.04 x 10-3? cm. Finally, the GAZO/ITIO bi-layer films, as a front electrode for silicon-based thin film solar cells, obtained a maximum efficiency of 7.10%. These encouraging experimental results have potential applications in GAZO/ITIO bi-layer film deposition by in-line sputtering without the wet-etching process and enable the production of highly efficient, low-cost thin film solar cells.

  10. Exploring the origin of the temperature-dependent behavior of PbS nanocrystal thin films and solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Szendrei, Krisztina; Speirs, Mark; Gomulya, Widianta; Jarzab, Dorota; Manca, Marianna; Mikhnenko, Oleksandr V.; Kooi, Bart J.; Loi, Maria A. [Zernike Institute for Advanced Materials, University of Groningen (Netherlands); Yarema, Maksym; Heiss, Wolfgang [Institute for Semiconductor and Solid State Physics, University of Linz (Austria)

    2012-04-24

    Temperature-dependent studies of the electrical and optical properties of cross-linked PbS nanocrystal (NC) solar cells can provide deeper insight into their working mechanisms. It is demonstrated that the overall effect of temperature on the device efficiency originates from the temperature dependence of the open-circuit voltage and the short-circuit current, while the fill factor remains approximately constant. Extensive modeling provides signs of band-like transport in the inhomogeneously coupled NC active layer and shows that the charge transport is dominated by diffusion. Moreover, via low temperature absorption and photoluminescence (PL) measurements, it is shown that the optical properties of PbS thin films before and after benzenedithiol (BDT) treatment exhibit very distinct behavior. After BDT treatment, both the optical density (OD) and PL are shifted to lower energies, indicating the occurrence of electronic wave function overlap between adjacent NCs. Decrease of the temperature leads to additional red-shift of the OD and PL spectra, which is explained by the well-known temperature dependence of the PbS NCs' bandgap. Moreover, BDT treated PbS NCs show unusual properties, such as decrease of the PL signal and broadening of the spectra at low temperatures. These features can be attributed to the partial relaxation of the quantum confinement and the opening of new radiative and nonradiative pathways for recombination at lower temperatures due to the presence of trap states. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. Separation of signals from amorphous and microcrystalline part of a tandem thin film silicon solar cell in Fourier transform photocurrent spectroscopy.

    Czech Academy of Sciences Publication Activity Database

    Holovský, Jakub; Poruba, Aleš; Bailat, J.; Van??ek, Milan

    München : WIP- Renewable Energies, 2007 - (Willeke, G.; Ossenbrink, H.; Helm, P.), s. 1851-1854 ISBN 3-936338-22-1. [European Photovoltaic Solar Energy Conference /22./. Milan (IT), 03.09.2007-07.09.2007] R&D Projects: GA MŽP(CZ) SN/3/172/05 Grant ostatní: Project EU LPAMS(XE) INCO-CT-2004-509178 Institutional research plan: CEZ:AV0Z10100521 Keywords : thin film silicon solar cell * Fourier transform photocurrent spectroscopy Subject RIV: BM - Solid Matter Physics ; Magnetism

  12. ZnO nanocolumns arrays for thin film amorphous si, tandem a-Si/a-Si and a-Si/?c Si solar cells.

    Czech Academy of Sciences Publication Activity Database

    Neykova, Neda; Hruška, Karel; Purkrt, Adam; Remeš, Zden?k; Holovský, Jakub; Poruba, Aleš; Van??ek, Milan

    Paris : WIP, 2013, s. 399-402. ISBN 3-936338-33-7. [European Photovoltaic Solar Energy Conference and Exhibition /28./. Paris (FR), 30.09.2013-04.10.2013] R&D Projects: GA MŠk 7E12029; GA ?R(CZ) GAP108/11/0937; GA MŠk(CZ) LM2011026 Grant ostatní: FP7 Fast Track(XE) NMP4-LA-2012-283501 Institutional support: RVO:68378271 Keywords : thin film silicon solar cell * ZnO nanocolumn * photothermal deflection spectroscopy Subject RIV: BM - Solid Matter Physics ; Magnetism

  13. Variation in Absorber Layer Defect Density in Amorphous and Microcrystalline Silicon Thin Film Solar Cells with 2 MeV Electron Bombardment

    Science.gov (United States)

    Smirnov, Vladimir; Astakhov, Oleksandr; Carius, Reinhard; Petrusenko, Yuri; Borysenko, Valeriy; Finger, Friedhelm

    2012-02-01

    The effect of the defect density in hydrogenated amorphous and microcrystalline silicon (a-Si:H and µc-Si:H) absorber layers on the performance of thin film solar cells was investigated. The defect density was varied reproducibly over more than two orders of magnitude by 2 MeV electron bombardment and subsequent thermal annealing. Considerable quantitative and qualitative differences were observed for the dependences of the cells parameters on the defect densities of a-Si:H and µc-Si:H. The experimental data suggest further possible improvement of µc-Si:H based solar cells with further reduced defect densities, while for a-Si:H based solar cells, a saturation of performance is observed below a defect density of about 1016 cm-3. Moreover, the experimental data provide an excellent database for numerical simulation over a range unavailable so far particularly in µc-Si:H based solar cells.

  14. Electron spin resonance investigaton of semiconductor materials for application in thin-film silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Lihong

    2012-07-01

    In the present work, hydrogenated silicon and its alloys silicon carbide and silicon oxide have been investigated using electron spin resonance (ESR). The microstructure of these materials ranges from highly crystalline to amorphous. The correlation between the paramagnetic defects, microstructure, optical and electrical properties has been discussed. Correspondingly, these properties were characterized by the spin density (N{sub S}), g-value and the lineshape of ESR spectra, Infrared (I{sup IR}{sub C}) and/or Raman crystallinity (I{sup RS}{sub C}) as well as optical absorption and electrical dark conductivity ({sigma}{sub D}). 1. As the light absorber, Si layers essentially should have low defect density and good stability against light exposure. The spin density (N{sub S}) measured by ESR is often used as a measure for the paramagnetic defect density (N{sub D}) in the material. However, ESR sample preparation procedures can potentially cause discrepancy between N{sub S} and N{sub D}. Using Mo-foil, Al-foil and ZnO:Al-covered glass as sacrificial substrates, {mu}c-Si:H and a-Si:H films were deposited by plasma-enhanced chemical vapor deposition (PECVD), and ESR powder samples have been prepared with corresponding procedures. Possible preparation-related metastability and instability effects have been investigated in terms of substrate dependence, HCl-etching and atmosphere exposure. A sequence of 'preparation - annealing - air-exposure - annealing' has been designed to investigate the metastability and instability effects. N{sub S} after post-preparation air exposure is higher than in the annealed states, especially for the highly crystalline {mu}c-Si:H material the discrepancy reached one order of magnitude. Low temperature ESR measurements at 40 K indicated that atmospheric exposure leads to a redistribution of the defect states which in turn influence the evaluated N{sub S}. In annealed conditions the samples tend to have lower N{sub S} presumably due to slight n-type character of undoped a-Si:H and {mu}c-Si:H. Therefore ESR evaluation leads to an underestimation of N{sub D} in the annealed states of highly crystalline {mu}c-Si:H. It has been concluded that N{sub S} in the exposed states represents N{sub D} more adequately than in the annealed states. 2. As the transparent conductive window layer, nominally undoped and Al-doped {mu}c-SiC:H thin films were prepared by hot-wire chemical vapor deposition (HWCVD). Samples with a wide range of crystallinity from highly crystalline (I{sup IR}{sub C} > 90%) to amorphous (I{sup IR}{sub C} = 0%) have been prepared with variation of the Monomethylsilane concentration (c{sub MMS}), the substrate and filament temperature (T{sub S}, T{sub F}), the gas pressure (p) and the Al-doping concentration (p{sub TMAl}/p{sub MMS}). In the nominally undoped {mu}c-SiC:H material, a high N{sub S} is observed over a wide range of crystallinity, whereas {sigma}{sub D} increases by 10 orders of magnitude up to 10{sup -2} S/cm as the material becomes more crystalline. The dramatic increase of {sigma}{sub D} has been attributed to both the higher material crystallinity and unintentional donor doping. The ESR spectrum changes from a broad featureless resonance in the low crystallinity material to a sharp line with a pair of distinct satellites in highly crystalline n-type {mu}c-SiC:H. The resonance center is constant at g = 2.003. The central resonance is associated with the paramagnetic states of Si- and/or C-vacancies (V{sub Si}, V{sub C}) at different charge states and dangling bonds (dbs) in disordered phases, and the observed hyperfine structure is speculated to be related to the unintentionally doped nitrogen. Al-doping leads to a compensation of donors. {sigma}{sub D} firstly dropped to the minimum of 10{sup -11} S/cm before increasing up to 4 x 10{sup -4} S/cm, while N{sub S} decreased to 5 x 10{sup 17} cm{sup -3} and then increased up to 2 x 10{sup 19} cm{sup -3}. Meanwhile, Al-doping also results in a loss of crystallinity (I{sup IR}{sub C}) of {mu}c-SiC:H material. Effective

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

    Energy Technology Data Exchange (ETDEWEB)

    Albin, David S.

    2015-06-13

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

  16. Preparation of coarse grained polycrystalline thin films for silicon solar cells. Final report; Praeparation von grobkoernig-polykristallinen Duennschichten fuer Solarzellen aus Silizium. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Andrae, G.; Bergmann, J.; Falk, F.; Ose, E.

    1999-06-01

    The project was to test methods for preparation of large-crystallite silicon thin films on glass by laser crystallization of amorphous silicon. Further, the properties of those thin films were examined for their suitability of use in solar cells. As the film thickness of some 10{mu}m, required for light absorption by crystalline silicon (unless light traps are used), cannot be achieved in one step via laser crystallization, a multi-step technique was proposed, the first step consisting of a conventional PECVD process for deposition of amorphous silicon films of some nm in thickness. This process was optimized, achieving the thin film properties required for subsequent laser crystallization, including resolution of some other problems involved, primarily those of reliable adhesive strength of the thin films, and their hydrogen content. As a second step, various techniques for laser crystallization of the amorphous thin films were tested and optimized. The objective was to prepare crystalline silicon thin films with a thickness of some hundred nm, consisting of crystallites as large as possible. The targeted size of crystallites was a lateral size of 100 {mu}m. (orig./CB) [German] In dem hier beschriebenen Projekt sollten Laserverfahren erprobt werden, um auf Glas moeglichst grosse Siliciumkristallite durch Kristallisation aus amorphem Siliciumschichten herzustellen. Weiterhin sollten die Eigenschaften dieser kristallinen Schichten mit Hinblick auf ihre Eignung fuer Solarzellen untersucht werden. Da die fuer die Lichtabsorption in kristallinem Silicum erforderliche Schichtdicke von einigen 10 {mu}m (wenn keine Lichtfallen eingesetzt werden) nicht in einem einzigen Schritt mit dem Laser kristallisiert werden kann, wurde ein Mehrschrittverfahren vorgeschlagen. In einem ersten Schritt sollte amorphes Silicium mit einer Schichtdicke von einigen hundert nm Dicke durch einen konventionellen PECVD-Prozess abgeschieden werden. Das Abscheideverfahren sollte so optimiert werden, dass sich die Schichten fuer die anschliessende Laserkristallisation eignen. Dazu waren insbesondere Forderungen an die Haftfestigkeit und den Wasserstoffgehalt zu stellen. In einem zweiten Schritt sollten verschiedene Verfahren zur Laserkristallisation der amorphen Schichten angewandt und optimiert werden. Das Ziel dieses Schrittes war, kristalline Siliciumschichten einer Dicke von einigen hundert nm mit moeglichst grossen Kristalliten herzustellen. Angestrebt war eine Kristallitgroesse von lateral 100 {mu}m. (orig.)

  17. Growth and Characterization of Thin Film Nanocrystalline Silicon Materials and Solar Cells:

    OpenAIRE

    Agbo, S.N.

    2012-01-01

    The need for electrical energy is growing fast as a result of the expanding world population and economic activities. On top of this the energy need of each individual is also growing. At present the growth in energy demand is not matched by the growth in energy generation because of insufficient energy production. This energy gap therefore needs to be bridged. In addition, most conventional means of energy generation are not environmentally-friendly and in turn affect human lives. Solar ...

  18. Triple-junction thin-film silicon solar cell fabricated on periodically textured substrate with a stabilized efficiency of 13.6%

    Science.gov (United States)

    Sai, Hitoshi; Matsui, Takuya; Koida, Takashi; Matsubara, Koji; Kondo, Michio; Sugiyama, Shuichiro; Katayama, Hirotaka; Takeuchi, Yoshiaki; Yoshida, Isao

    2015-05-01

    We report a high-efficiency triple-junction thin-film silicon solar cell fabricated with the so-called substrate configuration. It was verified whether the design criteria for developing single-junction microcrystalline silicon (?c-Si:H) solar cells are applicable to multijunction solar cells. Furthermore, a notably high short-circuit current density of 32.9 mA/cm2 was achieved in a single-junction ?c-Si:H cell fabricated on a periodically textured substrate with a high-mobility front transparent contacting layer. These technologies were also combined into a-Si:H/?c-Si:H/?c-Si:H triple-junction cells, and a world record stabilized efficiency of 13.6% was achieved.

  19. Sol–gel synthesis of intrinsic and aluminum-doped zinc oxide thin films as transparent conducting oxides for thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Salam, Shahzad [State Key Laboratory of New Ceramics and Fine Processing, Department of Material Science and Engineering, Tsinghua University (China); Islam, Mohammad, E-mail: miqureshi@ksu.edu.sa [Center of Excellence for Research in Engineering Materials (CEREM), Advanced Manufacturing Institute, King Saud University, P. O. Box 800, Riyadh 11421 (Saudi Arabia); Akram, Aftab [School of Chemical and Materials Engineering, National University of Sciences and Technology, Islamabad (Pakistan)

    2013-02-01

    Sol–gel synthesis of intrinsic (i-ZnO) and aluminum-doped zinc oxide (Al:ZnO) thin films was carried out via spin coating process using 0.2 M Zn{sup 2+} precursor salt, monoethanolamine to Zn{sup 2+} ratio of 0.75, and 1 and 2 at.% aluminum as a dopant. After annealing at 500 °C for 1 h, the structural, compositional, electrical, and optical properties of the films were investigated. Scanning electron microscope studies revealed smooth, dense film microstructure with granular cross-sectional morphology. The average grain size was in the range of 25 to 53 nm, depending on film composition, and indicated reduction in size with more Al incorporation. The processing conditions favored (002) preferential growth in all the films, with degree of preferred growth as high as 0.45, as determined from X-ray diffraction analysis. Al:ZnO film with 1 at.% Al was found to exhibit minimum resistivity value of 4.06 × 10{sup ?3} ? cm and carrier concentration as high as 5.52 × 10{sup 19} cm{sup ?3}. From optical transmittance spectra, the absorption edge of the films was determined to be at ? 370 nm with ? 80% transmittance in visible and near-infrared regions of the spectrum. The calculated values of band gap indicated continuous increase from 3.35 to 3.41 eV upon Al doping of the films. - Highlights: ? Sol–gel technique is used to produce intrinsic and aluminum-doped zinc oxide films. ? Doping with Al promotes 002 preferred orientation and decreases surface roughness. ? Films with 1 at.% Al show electrical resistivity of 4.5 × 10{sup ?3} ? cm. ? Optical transmittance is up to 85% with band gap in the range of 3.35 to 3.41 eV. ? 2 at.% Al in films causes deterioration of electrical and optical properties.

  20. Sol–gel synthesis of intrinsic and aluminum-doped zinc oxide thin films as transparent conducting oxides for thin film solar cells

    International Nuclear Information System (INIS)

    Sol–gel synthesis of intrinsic (i-ZnO) and aluminum-doped zinc oxide (Al:ZnO) thin films was carried out via spin coating process using 0.2 M Zn2+ precursor salt, monoethanolamine to Zn2+ ratio of 0.75, and 1 and 2 at.% aluminum as a dopant. After annealing at 500 °C for 1 h, the structural, compositional, electrical, and optical properties of the films were investigated. Scanning electron microscope studies revealed smooth, dense film microstructure with granular cross-sectional morphology. The average grain size was in the range of 25 to 53 nm, depending on film composition, and indicated reduction in size with more Al incorporation. The processing conditions favored (002) preferential growth in all the films, with degree of preferred growth as high as 0.45, as determined from X-ray diffraction analysis. Al:ZnO film with 1 at.% Al was found to exhibit minimum resistivity value of 4.06 × 10?3 ? cm and carrier concentration as high as 5.52 × 1019 cm?3. From optical transmittance spectra, the absorption edge of the films was determined to be at ? 370 nm with ? 80% transmittance in visible and near-infrared regions of the spectrum. The calculated values of band gap indicated continuous increase from 3.35 to 3.41 eV upon Al doping of the films. - Highlights: ? Sol–gel technique is used to produce intrinsic and aluminum-doped zinc oxide films. ? Doping with Al promotes 002 preferred orientation and decreases surface roughness. ? Films with 1 at.% Al show electrical resistivity of 4.5 × 10?3 ? cm. ? Optical transmittance is up to 85% with band gap in the range of 3.35 to 3.41 eV. ? 2 at.% Al in films causes deterioration of electrical and optical properties

  1. Effect of band-aligned double absorber layers on photovoltaic characteristics of chemical bath deposited PbS/CdS thin film solar cells.

    Science.gov (United States)

    Ho Yeon, Deuk; Chandra Mohanty, Bhaskar; Lee, Seung Min; Soo Cho, Yong

    2015-01-01

    Here we report the highest energy conversion efficiency and good stability of PbS thin film-based depleted heterojunction solar cells, not involving PbS quantum dots. The PbS thin films were grown by the low cost chemical bath deposition (CBD) process at relatively low temperatures. Compared to the quantum dot solar cells which require critical and multistep complex procedures for surface passivation, the present approach, leveraging the facile modulation of the optoelectronic properties of the PbS films by the CBD process, offers a simpler route for optimization of PbS-based solar cells. Through an architectural modification, wherein two band-aligned junctions are stacked without any intervening layers, an enhancement of conversion efficiency by as much as 30% from 3.10 to 4.03% facilitated by absorption of a wider range of solar spectrum has been obtained. As an added advantage of the low band gap PbS stacked over a wide gap PbS, the devices show stability over a period of 10 days. PMID:26394761

  2. Effect of band-aligned double absorber layers on photovoltaic characteristics of chemical bath deposited PbS/CdS thin film solar cells

    Science.gov (United States)

    Ho Yeon, Deuk; Chandra Mohanty, Bhaskar; Lee, Seung Min; Soo Cho, Yong

    2015-01-01

    Here we report the highest energy conversion efficiency and good stability of PbS thin film-based depleted heterojunction solar cells, not involving PbS quantum dots. The PbS thin films were grown by the low cost chemical bath deposition (CBD) process at relatively low temperatures. Compared to the quantum dot solar cells which require critical and multistep complex procedures for surface passivation, the present approach, leveraging the facile modulation of the optoelectronic properties of the PbS films by the CBD process, offers a simpler route for optimization of PbS-based solar cells. Through an architectural modification, wherein two band-aligned junctions are stacked without any intervening layers, an enhancement of conversion efficiency by as much as 30% from 3.10 to 4.03% facilitated by absorption of a wider range of solar spectrum has been obtained. As an added advantage of the low band gap PbS stacked over a wide gap PbS, the devices show stability over a period of 10 days. PMID:26394761

  3. Effect of band-aligned double absorber layers on photovoltaic characteristics of chemical bath deposited PbS/CdS thin film solar cells

    Science.gov (United States)

    Ho Yeon, Deuk; Chandra Mohanty, Bhaskar; Lee, Seung Min; Soo Cho, Yong

    2015-09-01

    Here we report the highest energy conversion efficiency and good stability of PbS thin film-based depleted heterojunction solar cells, not involving PbS quantum dots. The PbS thin films were grown by the low cost chemical bath deposition (CBD) process at relatively low temperatures. Compared to the quantum do