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1

Thin film solar cells  

Energy Technology Data Exchange (ETDEWEB)

Thin film solar cells need for their production only a small amount of materials and energy. By the thin-film-technology a great number of material combinations for solar cells can be realized. The developed systems of CdS/Cusub(x)S and of amorphous silicon are reported and the possibilities to reach higher efficiencies are discussed.

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

1980-07-01

2

Thin film solar cell  

Energy Technology Data Exchange (ETDEWEB)

A thin film solar cell formed on a substrate, comprising at least first and second electrodes, at least one of which is capable of passing light, a silicon film interposed between said first and second electrodes, and at least one junction formed in the silicon film for separating electrons and positive holes when the cell is exposed to light, wherein said silicon film comprises a mixed phase consisting of a polycrystalline phase and an amorphous phase, and includes at least about 50% by volume of fibrous crystalline grains, each of said grains having a maximum bottom diameter of about 1 ..mu..m and a minimum height of about 50 nm and having its grain boundaries terminated with a monovalent element. The solar cell has a high photoelectric conversion efficiency comparable to that of a single-crystal solar cell, and can be produced at a low cost.

Maruyama, E.; Ishizaka, A.; Katayama, Y.; Matsubara, H.; Murayama, Y.; Shimada, T.; Shintani, A.; Shiraki, Y.

1984-02-21

3

THIN-FILM SOLAR CELL  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract of WO 9805077 (A1) 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 ...

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

4

Thin-film solar cells  

International Nuclear Information System (INIS)

The rapid progress that is being made with inorganic thin-film photovoltaic (PV) technologies, both in the laboratory and in industry, is reviewed. While amorphous silicon based PV modules have been around for more than 20 years, recent industrial developments include the first polycrystalline silicon thin-film solar cells on glass and the first tandem solar cells based on stacks of amorphous and microcrystalline silicon films ('micromorph cells'). Significant thin-film PV production levels are also being set up for cadmium telluride and copper indium diselenide.

2009-07-01

5

US Polycrystalline Thin Film Solar Cells Program.  

Science.gov (United States)

The Polycrystalline Thin Film Solar Cells Program, part of the United States National Photovoltaic Program, performs R and D on copper indium diselenide and cadmium telluride thin films. The objective of the Program is to support research to develop cells...

H. S. Ullal K. Zweibel R. L. Mitchell

1989-01-01

6

Thin film solar cell  

Energy Technology Data Exchange (ETDEWEB)

Amorphous silicon (a-Si) solar cell is widely used as a power source for compact electronic equipments. This invention aims at forming a patterned transparent 1st electrode by using a transparent electrode printing ink, thus eliminating the conventional etching step with either ITO or SnO/sub 2/. A transparent electrode printing ink is first used to print a proper pattern on a glass plate; this is burned in a kiln to form a transparent 1st electrode; a-Si deposited layer and 2nd electrode (Al, etc.) are formed on this; thus a-Si solar cell wherein plural number of elements are directly connected on the same substrate. In this invention, the conventional use of vacuum equipment as in the vacuum evaporation and the spattering methods was eliminated; a large area treatment was made possible in this method of screen printing improving productivity. (2 figs)

Yamasaka, Koichi; Hanabusa, Akira; Mori, Koshiro

1987-06-25

7

Deposition techniques for thin film solar cells  

International Nuclear Information System (INIS)

Because of their high conversion efficiencies (?11%) reported in recent years, polycrystalline thin film solar cells have become strong contenders for low-cost solar electric generators (also known as photovoltaic modules). The low-cost potential for thin film solar cells has been recognized for quite sometimes. Because of this feature, amorphous silicon solar cells emerged in late seventies as potential candidates for mass scale production of solar modules and attracted significant interest and activity. During this period the efforts for the development thin film polycrystalline solar cells were rather limited. However, amorphous silicon solar cells have been observed to be unstable. This paper attempts briefly, to review the merits and short falls of various techniques for their suitability for large scale production solar modules.

1991-01-01

8

Printable CIGS thin film solar cells  

Science.gov (United States)

Among the various thin film solar cells in the market, CuInGaSe thin film solar cells have been considered as the most promising alternatives to crystalline silicon solar cells because of their high photo-electricity conversion efficiency, reliability, and stability. However, many fabrication methods of CIGS thin film are based on vacuum processes such as evaporation and sputtering techniques which are not cost efficient. This work develops a solution method using paste or ink liquid spin-coated on glass that would be competitive to conventional ways in terms of cost effective, non-vacuum needed, and quick processing. A mixture precursor was prepared by dissolving appropriate amounts of composition chemicals. After the mixture solution was cooled, a viscous paste was prepared and ready for spin-coating process. A slight bluish CIG thin film on substrate was then put in a tube furnace with evaporation of metal Se followed by depositing CdS layer and ZnO nanoparticle thin film coating to complete a solar cell fabrication. Structure, absorption spectrum, and photo-electricity conversion efficiency for the as-grown CIGS thin film solar cell are under study.

Fan, Xiaojuan

2013-03-01

9

Advances in thin-film solar cells  

CERN Multimedia

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

Dharmadasa, I M

2012-01-01

10

Thin-film solar cells. Duennschichtsolarzellen  

Energy Technology Data Exchange (ETDEWEB)

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

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

1990-01-01

11

Thin Film Solar Cells for Terrestrial Applications.  

Science.gov (United States)

The goals of the project are to develop a terrestrial version of the CdS thin film solar cell that is demonstrably amenable to low cost mass production, and to establish data on the lifetime of such cells under the expected conditions of terrestrial use. ...

F. A. Shirland W. J. Biter E. W. Greeneigh T. P. Brody

1975-01-01

12

Plasma texturing of thin film solar cells  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A potentially inexpensive way to texture silicon surfaces especially for crystalline silicon thin-film solar cells is the plasma texturing method. This method uses the principle of self-masking and is realised at Fraunhofer ISE using an isotropic and an anisotropic power supply. Even in continuous i...

Keller, M.; Janz, S.; Reber, S.; Lindekugel, S.

13

Thin film solar cell; Hakumaku taiyo denchi  

Energy Technology Data Exchange (ETDEWEB)

Generally, soda lime glass is used for the substrate of a thin film solar cell with a chalcopyrite type ternary compound semiconductor thin film, but, it has a problem that the adhesion of the soda lime glass and the electrode is weak due to the difference between thermal expansion coefficients of soda lime glass and Mo used for the electrode so as to cause exfoliation. This invention presents a thin film solar cell in which a thin film of I-III-VI2 group chalcopyrite type ternary compound is formed on a substrate of soda lime glass equipped with Mo electrode and a buffer layer composed of a metal whose thermal expansion coefficient is intermediate between soda lime glass and Mo is interposed between the glass substrate and the Mo electrode. As a result, even after a high temperature process such as a treatment in an atmosphere of a VI group element in selenization, lowering of the adhesion of the Mo electrode layer to the glass plate is suppressed and the exfoliation is prevented. Metals used in the buffer layer are tantalum, chromium, niobium and titanium. 1 fig.

Sato, H.

1994-09-09

14

Advanced characterization techniques for thin film solar cells  

Energy Technology Data Exchange (ETDEWEB)

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.

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

15

Amorphous thin film solar cell module  

Energy Technology Data Exchange (ETDEWEB)

Concerning an amorphous thin film solar cell module with a substrate of such opaque material as stainless steel and ceramics, etc., incidence of the light is on the side opposite to the substrate, therefore an acryl or melamine-based resin layer is provided for the protection of the surface of incidence of the light. However, these surface protection resins have shown a big reflection loss due to its low refraction factor, its hardness has not been sufficiently high and its manufacturing yield has been bad. In view of the above, with regard to the above cell module, this invention proposes to make the surface protection film, which is composed on the side of incidence of the light, of a diamond thin film. The invention states that because of the above, a surface protection film with a small light reflection loss, high hardness and good environment resistance can be obtained. (2 figs)

Sawai, Yoshiyasu

1988-07-21

16

Silicon Thin-Film Solar Cells  

Directory of Open Access Journals (Sweden)

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.

Guy Beaucarne

2007-01-01

17

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.

1987-09-18

18

Nanocrystalline silicon based thin film solar cells  

Science.gov (United States)

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

Ray, Swati

2012-06-01

19

Cigs thin film solar cells. Final report  

Energy Technology Data Exchange (ETDEWEB)

The Project CIGS Thin Film Solar Cells, phase 1 has been was a one-year project, bridging the time between the successful Aangstroem Solar Center research program and the four year project CIGS Thin Film Solar Cells, phase 2. There was one main goal in the plan and in the decision for the project which was to fabricate a 12.5x12.5 cm{sup 2} solar cell module with an efficiency of at least 13 % and containing no cadmium. This goal was achieved at the end of 2005 for a solar cell module which has an efficiency of 13.2 %. During 2005 the work has focussed on four important issues: Module technology - a complete module line for solar cell modules up to the size of 30x27.5 cm{sup 2} has been set up. The development of the different module process steps progressed towards a baseline process with high reproducibility and a mean value efficiency of close to 12 %. Cd-free buffer layers - Fundamental issues as e.g. bandgap matching between the CIGS absorber and the buffer layer. In this work, two different buffer layer materials have been studied: Zn(O,S) and (Zn,Mg)O, both of which are fabricated using Atomic Layer Deposition (ALD). We have found that it is possible to increase the efficiencies of Cd-free buffer layers beyond the efficiencies of the conventional Cd-containing buffers. Upscaling issues for Cd-free buffers - A new ALD-system was finalized at the end of 2004 and taken into operation during 2005. The objective with the new ALD-system was to test upscaling issues. A process for Zn(O,S) with good reproducibility and good homogeneity was developed during 2005. The sample size for the new ALD system is 12.5x12.5 cm{sup 2}, which means that it can be used in the minimodule line. High efficiency - The route to high efficiency involves both work with the CIGS layers in terms of compositional variations, especially regarding indium and gallium, but also work with the interface properties between the CIGS and the buffer layers. By using Zn(O,S) or (Zn,Mg)O buffer layers the absorption losses decrease as compared to buffers with CdS, thus the current density increases and thus the cell efficiency. The best cell result during 2005 was 17.2 %, using a Zn(O,S) buffer layer.

Edoff, Marika [Uppsala Univ., Dept. of Technical Sciences (Sweden). Solid state electronics div.

2006-10-15

20

2D modelling of polycrystalline silicon thin film solar cells  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The influence of grain boundary (GB) properties on device parameters of polycrystalline silicon (poly-Si) thin film solar cells is investigated by two-dimensional device simulation. A realistic poly-Si thin film model cell composed of antireflection layer, (n+)-type emitter, thick p-type absorber,...

Teodoreanu Ana-Maria; Friedrich Felice; Leihkauf Rainer; Boit Christian; Leendertz Caspar; Korte Lars

 
 
 
 
21

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

International Nuclear Information System (INIS)

[en]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

2001-01-01

22

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

Energy Technology Data Exchange (ETDEWEB)

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.

Schock, Hans-Werner; Pfisterer, Fritz [Stuttgart Univ. (Germany). Inst. fuer Physikalische Elektronik

2001-04-01

23

Recent technological advances in thin film solar cells  

Energy Technology Data Exchange (ETDEWEB)

High-efficiency, low-cost thin film solar cells are an exciting photovoltaic technology option for generating cost-effective electricity in 1995 and beyond. This paper reviews the substantial advances made by several thin film solar cell technologies, namely, amorphous silicon, copper indium diselenide, cadmium telluride, and polycrystalline silicon. Recent examples of utility demonstration projects of these emerging materials are also discussed. 8 refs., 4 figs.

Ullal, H.S.; Zwelbel, K.; Surek, T.

1990-03-01

24

Promising thin-film solar cells: an overview  

Energy Technology Data Exchange (ETDEWEB)

Several thin film solar cell materials have demonstrated greater than 10% conversion efficiency, including amorphous silicon, polycrystalline silicon, cadmium sulfide/copper sulfide, cadmium sulfide/copper indium diselenide, gallium arsenide (CLEFT), cadmium sulfide/cadmium telluride, and gallium arsenide/silicon. The generic category of thin film solar cells is examined to determine prerequisites for use of these materials for large quantities of competitive electrical energy production. The future extrapolated performance, low cost potential, and areas for further research are discussed.

Stone, J.L.

1983-05-01

25

Thin film cadmium telluride solar cells  

Energy Technology Data Exchange (ETDEWEB)

Thin-film p-CdTe/CdS/SnO/sub 2/:F/glass solar cells of the inverted configuration were prepared by the deposition of p-type CdTe films onto CdS/SnO/sub 2/:F/glass substrates using CVD or close-spaced sublimation (CSS) techniques based on the procedures of Chu et al. (1983) and Nicholl (1963), respectively. The deposition rates of p-CdTe films deposited by CSS were higher than those deposited by the CVD technique (4-5 min were sufficient), and the efficiencies higher than 10 percent were obtained. However, the resistivity of films prepared by CSS was not as readily controlled as that of the CVD films. The simplest technique to reduce the resistivity of the CSS p-CdTe films was to incorporate a dopant, such as As or Sb, into the reaction mixture during the preparation of the source material. The films with resistivities in the range of 500-1000 ohm cm were deposited in this manner. 5 references.

Chu, T.L.; Chu, S.S.; Ang, S.T.; Mantravadi, M.K.

1987-08-01

26

Thin films of tin sulphide for use in thin film solar cell devices  

International Nuclear Information System (INIS)

SnS is of interest for use as an absorber layer and the wider energy bandgap phases e.g. SnS2, Sn2S3 and Sn/S/O alloys of interest as Cd-free buffer layers for use in thin film solar cells. In this work thin films of tin sulphide have been thermally evaporated onto soda-lime glass substrates with the aim of optimising the properties of the material for use in superstrate configuration device structures. The thin films were characterised using energy dispersive X-ray analysis (EDS) to determine the film composition, X-ray diffraction (XRD) to determine the phases present and structure of each phase, transmittance versus wavelength measurements to determine the energy bandgap and scanning electron microscopy (SEM) to observe the surface topology and topography. These properties were then correlated to the deposition parameters. Using the optimised conditions it is possible to produce thin films of tin sulphide that are pinhole free and conformal to the substrate that are suitable for use in thin film solar cell structures.

2009-02-02

27

Thin film solar cells: research in an industrial perspective.  

UK PubMed Central (United Kingdom)

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)Se(2) and Cu(2)ZnSn(S,Se)(4) as the sunlight-absorbing layer.

Edoff M

2012-01-01

28

Thin Film Solar Cells: Research in an Industrial Perspective  

Energy Technology Data Exchange (ETDEWEB)

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)Se{sub 2} and Cu{sub 2}ZnSn(S,Se){sub 4} as the sunlight-absorbing layer

Edoff, Marika (Div. of Solid State Electronics, Dept. of Engineering Sciences, Aangstroem Laboratory, Uppsala Univ., Uppsala (Sweden)), E-mail: marika.edoff@angstrom.uu.se

2012-03-15

29

Mode Splitting for Efficient Plasmoinc Thin-film Solar Cell  

CERN Multimedia

We propose an efficient plasmonic structure consisting of metal strips and thin-film silicon for solar energy absorption. We numerically demonstrate the absorption enhancement in symmetrical structure based on the mode coupling between the localized plasmonic mode in Ag strip pair and the excited waveguide mode in silicon slab. Then we explore the method of symmetry-breaking to excite the dark modes that can further enhance the absorption ability. We compare our structure with bare thin-film Si solar cell, and results show that the integrated quantum efficiency is improved by nearly 90% in such thin geometry. It is a promising way for the solar cell.

Li, Tong; Jiang, Chun

2010-01-01

30

Physical characterization of thin-film solar cells  

Energy Technology Data Exchange (ETDEWEB)

The principal techniques used in the physical characterization of thin-film solar cells and materials are reviewed, these being scanning probe microscopy (SPM), X-ray diffraction (XRD), spectroscopic ellipsometry, transmission electron microscopy (TEM), Auger electron spectroscopy (AES), secondary-ion mass spectrometry (SIMS), X-ray photoelectron spectroscopy (XPS), photoluminescence and time-resolved photoluminescence (TRPL), electron-beam-induced current (EBIC) and light-beam-induced current (LBIC). For each method the particular applicability to thin-film solar cells is highlighted. Examples of the use of each are given, these being drawn from the chalcopyrite, CdTe, Si and III-V materials systems. (author)

Durose, K. [Durham Univ. (United Kingdom). Dept. of Physics; Asher, S.A. [National Renewable Energy Lab., Golden, CO (United States); Jaegermann, W. [Darmstadt Univ. of Technology (DE). Inst. of Materials Science] (and others)

2004-07-01

31

Development of a Cadmium Selenide Thin Film Solar Cell.  

Science.gov (United States)

A CdSe MIS thin film solar cell was developed. Fourteen materials were studied with regard to their suitability as I-layers. Two these compounds, i.e., ZnSe and Sb2Se3, give cells with relatively high photovoltage and high photocurrent. The preparation pr...

D. Bonnet

1979-01-01

32

Thin Film Solar Cells and their Optical Properties  

Directory of Open Access Journals (Sweden)

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.

Stanislav Jurecka; Emil Pincik; Robert Brunner

2006-01-01

33

Thin Film Solar Cells and their Optical Properties  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 spe...

Stanislav Jurecka; Emil Pincik; Robert Brunner

34

Improvements in CdS Thin Film Solar Cells.  

Science.gov (United States)

The performance of two CdS thin film solar cell flight panels, which were included in a satellite experiment in a high radiation orbit, showed no serious degradation after a period of 130 days. The results of balloon flight calibration tests indicate that...

H. E. Nastelin

1968-01-01

35

Investigation of CDS Thin-Film Solar Cells.  

Science.gov (United States)

Research and development of front wall, thin film, flexible, light weight CdS solar cells was continued and decided improvements have been accomplished. A one square foot array shows a power to weight ratio of about 35.0 watts/lb. with an overall area uti...

1965-01-01

36

Hydrogen Passivation of Polycrystalline Si Thin Film Solar Cells  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

Gorka, Benjamin

37

Structure and performance of polycrystalline thin film solar cells  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A review of recent advances in polycrystalline thin film solar cells is presented. A comparison of the fundamental mechanisms and the performance of heterojunction, Schottky barrier, metal-insulator-semiconductor, inversion layer and p-n junction devices is given. The emphasis is placed on devices f...

S Yang, E

38

Optical confinement in recrystallised wafer equivalent thin film solar cells  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Bragg reflectors were used to enhance rear-side optical confinement in crystalline silicon thin film solar cells. Besides the enhancement of reflectivity in the long wavelength region, the layer stack acts as a diffusion barrier. We designed two different Bragg reflectors which were deposited on dif...

Janz, S.; Kuenle, M.; Peters, M.; Lindekugel, S.; Mitchell, E.J.; Reber, S.

39

Emitter epitaxy for crystalline silicon thin-film solar cells  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper presents results of crystalline silicon thin-film solar cells (cSiTF) with in-situ epitaxial emitters deposited by high temperature atmospheric pressure CVD. Emitters formed by epitaxy could provide an alternative for an adjustable emitter shape with a short deposition time. Simulation re...

Schmich, E.; Reber, S.; Hees, J.; Trenkle, F.; Schillinger, N.; Willeke, G.

40

UV imprinting for thin film solar cell application  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 fid...

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

 
 
 
 
41

Thin film solar cells made from amorphous silicon  

Energy Technology Data Exchange (ETDEWEB)

It is reported on the recent developments in the field of thin film solar cells made from amorphous silicon. The basic material parameters like density of states and diffusion length and their importance for the conversion efficiency of the solar cells is discussed. The current status of research activity is reviewed in the light of design concepts aimed at achieving higher efficiencies and better long life stability.

Kruehler, W.

1985-08-01

42

New thin film solar cells and development of tandem systems  

Energy Technology Data Exchange (ETDEWEB)

The structure and method of functioning of tandem systems in thin-film solar cells is outlined. Problems of putting into practice this kind of layout e.g. selection of suitable semiconductor materials and the layer sequence, are thoroughly discussed. The laboratory data already available indicate that levels of effectiveness approximately equal to or above those of single-crystal solar cells could be attained.

Pfisterer, F.; Schock, H.W.; Arndt, W.; Bloss, W.H.

1982-01-01

43

Ternary Compound Thin Film Solar Cells.  

Science.gov (United States)

This research program is directed toward the growth and characterization of I-III-V1 sub 2 ternary compound thin films and the use of these films in the development of photovoltaic devices for terrestrial application. The materials under investigation are...

L. L. Kazmerski

1976-01-01

44

Compound semiconductor thin films: a solar cell research opportunity  

Energy Technology Data Exchange (ETDEWEB)

Achievement of 10% conversion efficiency with three compound thin-film solar cell material systems does not exhuast this field of research and development. Many other candidate materials have been reported, even the best-known are only partially understood, and some remain unexplored. Recent experience suggests that barriers to making experimental cells, such as purity and lattice matching, can be less constraining than believed earlier. Oxygen and nitrogen can exhibit beneficial effects in some systems, and metallic contacting difficulties may be eased through the use of transparent conductors. Many materials are compatible with inexpensive non-vacuum deposition processes, and reactive sputtering can serve as a protean tool for building experimental solar cells. The authors urge a broad attack on the large unknown potential of compound semiconductor thin-film solar cells.

Gay, C.F.; Kapur, V.K.

1983-05-01

45

Thin-film crystalline silicon solar cells  

CERN Multimedia

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.

Brendel, Rolf

2011-01-01

46

Buried contact multijunction thin film silicon solar cell  

Energy Technology Data Exchange (ETDEWEB)

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.

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

1995-08-01

47

TCAD simulations for thin film solar cells with nanoplate structures.  

UK PubMed Central (United Kingdom)

The novel thin film solar cell with a nanoplate structure that can solve the conflict between the light absorption and the carrier transport in amorphous silicon thin film solar cell was investigated by TCAD simulations. This new structure has n-type amorphous silicon nanoplate array on the substrate, and p-type amorphous silicon-carbon as window layer and intrinsic amorphous silicon as absorption layer are sequentially grown along the surface of each n-type amorphous silicon nanoplate. Under AM 1.5 G sunlight illumination, the light is absorbed along the vertical direction of nanoplate while the carrier transport is along the horizontal direction. Therefore, nanoplate with the larger height can absorb most of the sunlight. The advantage of this novel structure is that the thickness of the solar cell can be used as thin as possible for effective transport of photo-generated carriers in comparison with the planer one.

Chang ST; Lin WK; Liu YC

2012-07-01

48

TCAD simulations for thin film solar cells with nanoplate structures.  

Science.gov (United States)

The novel thin film solar cell with a nanoplate structure that can solve the conflict between the light absorption and the carrier transport in amorphous silicon thin film solar cell was investigated by TCAD simulations. This new structure has n-type amorphous silicon nanoplate array on the substrate, and p-type amorphous silicon-carbon as window layer and intrinsic amorphous silicon as absorption layer are sequentially grown along the surface of each n-type amorphous silicon nanoplate. Under AM 1.5 G sunlight illumination, the light is absorbed along the vertical direction of nanoplate while the carrier transport is along the horizontal direction. Therefore, nanoplate with the larger height can absorb most of the sunlight. The advantage of this novel structure is that the thickness of the solar cell can be used as thin as possible for effective transport of photo-generated carriers in comparison with the planer one. PMID:22966571

Chang, S T; Lin, W K; Liu, Y C

2012-07-01

49

Thin-film solar cells: device measurements and analysis  

Energy Technology Data Exchange (ETDEWEB)

Characterization of amorphous Si, CdTe, and Cu(InGa)Se{sub 2}-based thin-film solar cells is described with focus on the deviations in device behavior from standard device models. Quantum efficiency (QE), current-voltage (J-V), and admittance measurements are reviewed with regard to aspects of interpretation unique to the thin-film solar cells. In each case, methods are presented for characterizing parasitic effects common in these solar cells in order to identify loss mechanisms and reveal fundamental device properties. Differences between these thin-film solar cells and idealized devices are largely due to a high density of defect states in the absorbing layers and to parasitic losses due to the device structure and contacts. There is also commonly a voltage-dependent photocurrent collection which affects J-V and QE measurements. The voltage and light bias dependence of these measurements can be used to diagnose specific losses. Examples of how these losses impact the QE, J-V, and admittance characterization are shown for each type of solar cell. (author)

Hegedus, S.S.; Shafarman, W.N. [University of Delaware, Newark, DE (United States). Inst. of Energy Conversion

2004-07-01

50

Photon upconversion for thin film solar cells  

Science.gov (United States)

In this research one of the many possible methods to increase the efficiency of solar cells is described. The method investigated is based on adapting the solar light in such a way that the solar cell can convert more light into electricity. The part of the solar spectrum that is adapted is the part that cannot be absorbed by the solar cells, because the photon energy is too low. This conversion of light is done by so called upconversion, which means that lower energy photons are converted into higher energy photons that can be absorbed by the solar cell. The upconverters used in this thesis are those based on lanthanide ions doped in crystalline hosts. Lanthanide ions have very specific absorption and emission lines, which means that by choosing an appropriate ion one can convert any arbitrary wavelength. One of the most important aspects when one wants to apply upconverters onto solar cells is the light intensity necessary for efficient conversion. Because the upconversion process requires two photons to make a new, higher energy photon, the conversion process is non-linearly dependent on the light intensity. This is the main limitation for practical applications. Therefore, next to applying upconverters onto solar cells also more fundamental questions are addressed in this thesis, for instance, the question what determines efficient conversion. At first the upconverter materials in different hosts are characterized and investigated. The host material influences non-radiative decays, the absorption strength, the lifetime and the energy transfer rate between the lanthanide ions. By investigating two upconverter hosts with small differences (? and ?-NaYF4 doped with Er3+ and Yb3+), we have tried to investigate the origin of the difference in upconversion efficiency. For this, emission and absorption spectra are measured under the same conditions and concentrations of the lanthanide ions. Also the absorption strength on the upconverter efficiency is investigated. For this, another host material (Gd2O2S:Er3+, Yb3+) was characterized and coupling of ?-NaYF4 upconverter with a plasmon resonance is investigated. The second part of the research is concerned with application of the upconverter onto solar cells. In this research the ?-NaYF4 and Gd2O2S upconverters were applied onto amorphous silicon solar cells (a-Si:H). At first, proof of principle experiments on solar cells with ?-NaYF4 upconverter were performed with laser light. I-V curves were measured and an increased response was determined in the upconverter solar cells. Finally, to proof viability of the concept further a set-up was made to concentrate simulated solar light. Concentration of solar light is not uncommon and more real life than laser light. All wavelengths longer than 900 nm were concentrated, which means that the range of the spectrum was much broader than the part that is absorbed by the upconverter. As upconverter material Gd2O2S was applied. Though a large part of the response is due to sub band gap defect absorption an increased response due to the upconverter was measured as well. The upconverter efficiency is thus high enough under moderate concentration of sunlight.

de Wild, J.

2012-09-01

51

Thin-film silicon solar cells with integrated silver nanoparticles  

International Nuclear Information System (INIS)

Thin-film silicon solar cells need efficient light absorption to achieve high efficiencies. The standard light trapping approach consists of a randomly textured transparent substrate and a highly reflective back contact. In this case, light scattering at the rough TCO-silicon interface leads to a prolonged absorption path and consequently to an increased short circuit current. In this study, we will discuss a new approach based on silver nanoparticles to improve the light absorption in the thin-film silicon solar cells. Raman and SNOM measurements and theoretical investigations on systems with metallic nanoparticles indicate a strong increase of the electric field in their surrounding when they are irradiated by light. Moreover, nanoparticles with the proper diameter can enhance light scattering. In this study, we have investigated the influence of silver nanoparticles with different sizes on the optoelectronic properties of amorphous and microcrystalline silicon solar cells. The nanoparticles are located at the back contact of the thin-film solar cell deposited in a n-i-p layer sequence.

2008-08-30

52

Vibrational spectroscopy of organic thin films used for solar cells  

Science.gov (United States)

We review infrared and Raman analyses of thin films of organic semiconductors used for active layers in organic solar cells. We present Raman study of blend (bulk heterojunction) films of regioregular poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM). The contents of the crystalline region of P3HT in the blend films prepared by various methods were estimated by Raman spectroscopy. Temperature dependence of photoinduced infrared absorption from a P3HT:PCBM blend film gives the activation energy of the recombination of photoinduced positive and negative carriers. The activation energies for P3HT:PCBM blend films with various PCBM contents were obtained. It has been demonstrated that infrared and Raman spectroscopy is useful for evaluating thin films of P3HT:PCBM blend films used for organic solar cells.

Furukawa, Yukio

2013-09-01

53

Laser scribing integration of polycrystalline thin film solar cells  

Science.gov (United States)

The growing demand for high productivity in the thin-film photovoltaic module industry, together with the request for more and more efficient devices, needs high-performance laser-scribing. The results of scribing tests on CdTe and CIGS solar cells samples are here presented. A comparison between the scribes obtained with ns regime fiber lasers, and a ps regime diode pumped solid state laser will be also reported.

Sozzi, Michele; Manilia, Filomena; Antezza, Roberto; Catellani, Cristina; Candiani, Alessandro; Coscelli, Enrico; Cucinotta, Annamaria; Selleri, Stefano; Menossi, Daniele; Bosio, Alessio

2013-03-01

54

Characterization of CdTe thin film solar cells  

International Nuclear Information System (INIS)

[en]The authors present experimental results on two types of solar cells produced from electrodeposited CdTe thin films, i.e., n-i-p CdS/CdTe/ZnTe and n-p CdS/CdTe structures. Some of the unique properties of the n-i-p structure are highlighted. They show that the distribution of the electric field in the entire CdTe layer is crucial to the production of high efficiency

1988-01-01

55

Microcrystalline Organic Thin-Film Solar Cells.  

UK PubMed Central (United Kingdom)

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.

Verreet B; Heremans P; Stesmans A; Rand BP

2013-08-01

56

Thin film polycrystalline silicon solar cells  

Energy Technology Data Exchange (ETDEWEB)

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.

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

1980-01-01

57

Development of thin film solar cell based on Cu{sub 2}ZnSnS{sub 4} thin films  

Energy Technology Data Exchange (ETDEWEB)

Cu{sub 2}ZnSnS{sub 4} (hereafter CZTS) thin films were successfully formed by vapor-phase sulfurization of precursors on a soda lime glass substrate (hereafter SLG) and a Mo-coated one (hereafter Mo-SLG). From the optical properties, we estimate the band-gap energy of this thin film as 1.45-1.6eV which is quite close to the optimum value for a solar cell. By using this thin film as an absorber layer, we could fabricate a new type of thin film solar cell, which was composed of Al/ZnO:Al/CdS/CZTS/Mo-SLG. The best conversion efficiency achieved in our study was 2.62% and the highest open-circuit voltage was 735mV. These device results are the best reported so far for CZTS.

Katagiri, H.; Saitoh, K.; Washio, T.; Shinohara, H.; Kurumadani, T.; Miyajima, S. [Department of Electrical Engineering, Nagaoka National College of Technology, 888 Nishikatakai, Nagaoka, 940-8532 Niigata (Japan)

2001-01-01

58

Plasmonic versus dielectric enhancement in thin-film solar cells  

DEFF Research Database (Denmark)

Several studies have indicated that broadband absorption of thin-film solar cells can be enhanced by use of surface-plasmon induced resonances of metallic parts like strips or particles. The metallic parts may create localized modes or scatter incoming light to increase absorption in thin-film semiconducting material. For a particular case, we show that coupling to the same type of localized slab-waveguide modes can be obtained by a surface modulation consisting of purely dielectric strips. The purely dielectric device turns out to have a significantly higher broadband enhancement factor compared to its metallic counterpart. We show that the enhanced normalized short-circuit current for a cell with silicon strips can be increased 4 times compared to the best performance for strips of silver, gold, or aluminium. For this particular case, the simple dielectric grating may outperform its plasmonic counterpart due to the larger Ohmic losses associated with the latter.

Dhring, Maria Bayard; Mortensen, N. Asger

2012-01-01

59

Thin film solar cell including a spatially modulated intrinsic layer  

Energy Technology Data Exchange (ETDEWEB)

One or more thin film solar cells in which the intrinsic layer of substantially amorphous semiconductor alloy material thereof includes at least a first band gap portion and a narrower band gap portion. The band gap of the intrinsic layer is spatially graded through a portion of the bulk thickness, said graded portion including a region removed from the intrinsic layer-dopant layer interfaces. The band gap of the intrinsic layer is always less than the band gap of the doped layers. The gradation of the intrinsic layer is effected such that the open circuit voltage and/or the fill factor of the one or plural solar cell structure is enhanced.

Guha, Subhendu (Troy, MI); Yang, Chi-Chung (Troy, MI); Ovshinsky, Stanford R. (Bloomfield Hills, MI)

1989-03-28

60

Efficient optical absorption in thin-film solar cells.  

UK PubMed Central (United Kingdom)

In order to improve the optical absorption of hydrogenated amorphous silicon (a-Si:H) thin film solar cells, a new structure consisted of ITO layer with the nonresonant nanoparticles embedded in it and a-Si:H layer, is proposed. By optimizing both the thickness of a-Si:H layer and nanoparticles size, the effects of Fabry-Perot resonance and the scattering of incident light are discussed and analyzed. It is demonstrated that the enhanced optical absorption can be achieved due to the coupling of incident light and nanostructure, simultaneously the proposed structure can be considered as gradient refractive index structure to restrain the reflection at the interface of ITO and a-Si:H thin film.

Yang L; Xuan Y; Tan J

2011-09-01

 
 
 
 
61

Thin-film silicon solar cells on mullite substrates  

Energy Technology Data Exchange (ETDEWEB)

Here we review the different methods used to create thin-film silicon solar cells on the most suitable ceramic substrates, namely alumina and mullite. The chemical vapor deposition (CVD) process on bare ceramics, the CVD on glassy layers (CVD-OGL) process, and the aluminum-induced crystallization (AIC) technique are reported and compared in terms of grain size, grain distribution and crystallographic orientation. The electrical quality of such layers was investigated through their open-circuit voltage before and after hydrogenation. Values up to 410mV were measured on n{sup +}p mesa cell structures on ceramics. (author)

Slaoui, A.; Pihan, E.; Focsa, A. [InESS (Institut d' Electronique du Solide et des Systemes)?CNRS, 23 rue du Loess, F-67037 Strasbourg (France)

2006-06-15

62

Thin film transistors and solar cells. (Latest citations from the US Patent bibliographic file with exemplary claims). Published Search  

Energy Technology Data Exchange (ETDEWEB)

The bibliography contains citations of selected patents concerning the fabrication and application methods of thin film transistors and thin film solar cells. Methods of manufacturing thin film transistors for use in electronic display devices are presented. Techniques for continuously producing durable and reliable thin film solar cells are discussed. (Contains 250 citations and includes a subject term index and title list.)

NONE

1995-01-01

63

Thin film transistors and solar cells. (Latest citations from the US Patent Bibliographic File with Exemplary Claims). Published Search  

Energy Technology Data Exchange (ETDEWEB)

The bibliography contains citations of selected patents concerning the fabrication and application methods of thin film transistors and thin film solar cells. Methods of manufacturing thin film transistors for use in electronic display devices are presented. Techniques for continuously producing durable and reliable thin film solar cells are discussed. (Contains 250 citations and includes a subject term index and title list.)

1993-11-01

64

Development of CIGS2 thin film solar cells  

Energy Technology Data Exchange (ETDEWEB)

Research and development of CuIn{sub 1-x}Ga {sub x}Se{sub 2-y}S {sub 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 SiO{sub 2} 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 H{sub 2}S. Presently large (15 cm x 10 cm) CuIn{sub 1-x}Ga {sub x}S{sub 2} (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:H{sub 2}S(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.

Dhere, Neelkanth G. [Florida Solar Energy Center, Cocoa, FL 32922 (United States)]. E-mail: dhere@fsec.ucf.edu; Gade, Vivek S. [Florida Solar Energy Center, Cocoa, FL 32922 (United States); Kadam, Ankur A. [Florida Solar Energy Center, Cocoa, FL 32922 (United States); Jahagirdar, Anant H. [Florida Solar Energy Center, Cocoa, FL 32922 (United States); Kulkarni, Sachin S. [Florida Solar Energy Center, Cocoa, FL 32922 (United States); Bet, Sachin M. [Florida Solar Energy Center, Cocoa, FL 32922 (United States)

2005-02-15

65

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

2005-02-15

66

Thin Film Solar Cells for Terrestrial Applications.  

Science.gov (United States)

Steady improvements have been effected in the control of cell processing. This has resulted in improved understanding of the cell construction and in higher shunt resistances. These in combination with improved handling have enabled evaporated fine mesh g...

F. A. Shirland W. J. Biter E. W. Greeneich A. J. Simon T. P. Brody

1975-01-01

67

Thin film solar cell and manufacturing method of a hetero-junction thin film solar cell; Usumaku taiyo denchi oyobi hetero setugo usumaku taiyo denchi no seizo hoho  

Energy Technology Data Exchange (ETDEWEB)

This invention aims to present a thin film solar cell and its manufacturing method using a hetero-junction compound semiconductor thin film as a photoabsorption layer containing no toxic cadmium with high conversion efficiency which is suitable for mass production and easy to produce a large area thin film. In this invention, transparent amorphous silicon semiconductor thin film is made to grow as an interface layer (buffer layer) with high resistance by the photochemical vapor deposition method on the interface between the first multi-component compound semiconductor thin film as a photoabsorption layer with p-type conduction on the metal back electrode and the second transparent and conductive metal oxide semiconductor thin film as a window layer with n-type conduction and broad forbidden bandwidth. The amorphous silicon semiconductor thin film is composed of a single intrinsic amorphous silicon semiconductor thin film containing no dopant or a stacked layer of n-type amorphous silicon semiconductor thin film formed on an intrinsic amorphous silicon semiconductor thin film. 7 figs.

Kushiya, K. [Showa Shell Sekiyu Kabusiki Kaisya, Tokyo (Japan); Konagai, M. [Tokyo (Japan)

1997-04-15

68

New developments in amorphous thin-film silicon solar cells  

Energy Technology Data Exchange (ETDEWEB)

Thin-film silicon solar cells usually contain amorphous silicon layers made by plasma enhanced chemical vapor deposition (PECVD). This CVD method has the advantage that large-area devices can be manufactured at a low processing temperature, thus facilitating low-cost solar cells on glass, metal foil, or polymer foil. In order to obtain higher conversion efficiencies while keeping the manufacturing cost low, a new development is to introduce low bandgap materials in a multijunction device structure. A frequently used low bandgap material is amorphous silicon germanium. Record initial efficiencies in excess of 15% have been reported for triple-junction solar cells comprising these alloys. In this paper, the authors present a novel manufacturing method for amorphous silicon based tandem cells suitable for roll-to-roll production.

Schropp, R.E.I.; Zeman, M.

1999-10-01

69

Ge/Si quantum dots thin film solar cells  

Science.gov (United States)

Thin film p-i-n solar cells (SCs) with 30 bilayers undoped or p-type self-assembled Ge/Si quantum dots (QDs) were fabricated on n+-Si(001) substrates by ultrahigh vacuum chemical vapor deposition. Compared with the SCs without Ge QDs, the external quantum efficiency in infrared region and the short-circuit current densities of the SCs with Ge QDs increased. However, their open-circuit voltages and efficiencies decreased. The open circuit voltages of p-type Ge/Si QDs SCs recovered significantly at low temperature, which was due to the suppression of recombination centers and longer carrier lifetime.

Liu, Zhi; Zhou, Tianwei; Li, Leliang; Zuo, Yuhua; He, Chao; Li, Chuanbo; Xue, Chunlai; Cheng, Buwen; Wang, Qiming

2013-08-01

70

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.

2009-02-02

71

???????????????? Optimization of Amorphous Silicon Thin Film Solar Cells Production Process  

Directory of Open Access Journals (Sweden)

Full Text Available ???????????????????????????????AZO???????Al???????????????????????????????????Minitab?????????????????????????????????????????????????Al???????????????????????????????????????????????AZO??????????Ar?????????????????????????????????????????????????????During the glass substrate amorphous silicon thin film solar cell production process, the laser scribe 2, sputtering AZO back reflected film, sputtering Al film, and laser scribe 3 etc. processes, have great effect on the maximum power (Pmax) of the solar cell. In this paper, we use Minitab software to design factorial experiment and optimize the process parameters. By analyzing the experimental data, we get the conclusion that, between an acceptable range, the sputtering power of Al film has the greatest effect on the Pmax of the solar cell, which increases while the sputtering power increases?and the Pmax increases as the current of laser scribe 3, puttering power of Al films and flux of Ar increase. Otherwise, Pmax decreases as the current of laser scribe 2 increases. By using the factorial experiment, we get the optimum parameters of the process for the present production line.

???; ??; ???; ???; ???; ???

2011-01-01

72

2D modelling of polycrystalline silicon thin film solar cells  

Science.gov (United States)

The influence of grain boundary (GB) properties on device parameters of polycrystalline silicon (poly-Si) thin film solar cells is investigated by two-dimensional device simulation. A realistic poly-Si thin film model cell composed of antireflection layer, (n+)-type emitter, thick p-type absorber, and (p+)-type back surface field was created. The absorber consists of a low-defect crystalline Si grain with an adjacent highly defective grain boundary layer. The performances of a reference cell without GB, one with n-type and one with p-type GB, respectively, are compared. The doping concentration and defect density at the GB are varied. It is shown that the impact of the grain boundary on the poly-Si cell is twofold: a local potential barrier is created at the GB, and a part of the photogenerated current flows within the GB. Regarding the cell performance, a highly doped n-type GB is less critical in terms of the cells short circuit current than a highly doped p-type GB, but more detrimental in terms of the cells open circuit voltage and fill factor.

Teodoreanu, Ana-Maria; Friedrich, Felice; Leihkauf, Rainer; Boit, Christian; Leendertz, Caspar; Korte, Lars

2013-07-01

73

2D modelling of polycrystalline silicon thin film solar cells  

Directory of Open Access Journals (Sweden)

Full Text Available The influence of grain boundary (GB) properties on device parameters of polycrystalline silicon (poly-Si) thin film solar cells is investigated by two-dimensional device simulation. A realistic poly-Si thin film model cell composed of antireflection layer, (n+)-type emitter, thick p-type absorber, and (p+)-type back surface field was created. The absorber consists of a low-defect crystalline Si grain with an adjacent highly defective grain boundary layer. The performances of a reference cell without GB, one with n-type and one with p-type GB, respectively, are compared. The doping concentration and defect density at the GB are varied. It is shown that the impact of the grain boundary on the poly-Si cell is twofold: a local potential barrier is created at the GB, and a part of the photogenerated current flows within the GB. Regarding the cell performance, a highly doped n-type GB is less critical in terms of the cells short circuit current than a highly doped p-type GB, but more detrimental in terms of the cells open circuit voltage and fill factor.

Teodoreanu Ana-Maria; Friedrich Felice; Leihkauf Rainer; Boit Christian; Leendertz Caspar; Korte Lars

2013-01-01

74

Recent advances in thin film CdTe solar cells  

Energy Technology Data Exchange (ETDEWEB)

CdTe thin film solar cells have been fabricated on a variety of glass substrates (borosilicate and soda lime). The CdS films were deposited to a thickness of 500{endash}2000 A by the chemical bath deposition (CBD), rf sputtering, or close spaced sublimation (CSS) processes. The CdTe films were deposited by CSS in the temperature range of 450{endash}625{degree}C. The main objective of this work is to fabricate high efficiency solar cells using processes that can meet low cost manufacturing requirements. In an attempt to enhance the blue response of the CdTe cells, ZnS films have also been prepared (CBD, rf sputtering, CSS) as an alternative window layer to CdS. Device behavior has been found to be consistent with a recombination model. {copyright} {ital 1996 American Institute of Physics.}

Ferekides, C.S.; Ceekala, V.; Dugan, K.; Killian, L.; Oman, D.; Swaminathan, R.; Morel, D. [Department of Electrical Engineering, University of South Florida, 4202 E. Fowler Ave., Tampa, Florida 33620 (United States)

1996-01-01

75

Transmission electron microscopy for thin film solar cells  

International Nuclear Information System (INIS)

Thin-film amorphous and microcrystalline silicon are promising materials for photovoltaics as they have the potential to reduce the solar cell costs. In case of microcrystalline silicon the crystalline volume fraction is related to the efficiency factor of solar cells because it provides information about the microstructure of the material and the defect density. With Transmission Electron Microscopy of cross-sections it is possible to show the microstructure of the cells. However to determine the structure of the bulk it is necessary to analyse the diffraction of the electron beam. For the purpose of imaging diffraction patterns and displaying dark fields a new camera system has been installed in the Phillips CM200. With much higher sensitivity and a larger photoactive area it is possible to take images of the low-intensity diffraction and the dark field patterns.

2011-01-01

76

Umwelt- und Gesundheitsauswirkungen der Herstellung und Anwendung sowie Entsorgung von Duennschichtsolarzellen und Modulen. Kenntnisstandbericht. (Effects of the production, use and disposal of thin film solar cells and modules on environment and health. Status report).  

Science.gov (United States)

The following subjects were investigated in the framework of this research report: Basic materials for thin film solar cells; Production of thin film solar cells; Uses and performance of thin film solar cells; Disposal of thin film solar cells. (HW)

H. Steinberger

1995-01-01

77

Accuracy of defect distributions measured by bias dependent admittance spectroscopy on thin film solar cells  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Thin film solar cells have achieved efficiencies up to 20%. Despite these excellent results, the understanding of the underlying mechanisms and the influence of defects on their performance is still incomplete. In thin film solar cells often defect level distributions are present rather than discret...

Decock, Koen; Khelifi, Samira; Burgelman, Marc

78

Trends in development of CuInSe sub 2 thin-film solar cells  

Energy Technology Data Exchange (ETDEWEB)

Recently, efforts for developing thin-film solar cells aimed to help reduce appliance cost are extensive. Already, amorphous Si solar cells and CdTe solar cells have been introduced to the market as power supply for hand-held calculators and other domestic appliances. Before thin-film solar cells can be used for electric power, the conversion efficiency must be improved. In this circumstance, attention is focused on CuInSe{sub 2} thin-film solar cells. Great efficiency improvement is expected when they are combined with amorphous Si solar cells into a tandem structure. This material will not deteriorate during a reasonable period of use, so it is very reliable. This paper discusses recent activities for developing CuInSe{sub 2} thin-film solar cells and tandem solar cells combining amorphous Si and CuInSe{sub 2} solar cells and discusses the future outlook. 23 refs., 7 figs., 4 tabs.

Nakata, Tokio; Kunioka, Akio (Aoyama Gakuin Univ. School of Science and Engineering, Tokyo, Japan (JP))

1988-11-30

79

High efficiency copper ternary thin film solar cells  

Energy Technology Data Exchange (ETDEWEB)

This report describes work to develop a high efficiency, thin film CuInSe{sub 2} solar cell using a potentially low-cost process. The technique used in this development program is a two-stage process. The two-stage process involves depositing the metallic elements of the CuInSe{sub 2} compound (i.e., Cu and In) on a substrate in the form of stacked layers, and then selenizing this stacked metallic film in an atmosphere containing Se. Early results showed that the electrodeposition/selenization technique could yield CuInSe{sub 2} films with good electrical and optical properties on small-area substrates. This report concentrates on the later half of the research effort; this portion was directed toward developing a two-stage process using evaporated Cu-In layers. The selenization technique has the potential of yielding solar cells with efficiencies in excess of 15 percent. 7 refs., 12 figs.

Basol, B.M.; Kapur, V.K. (International Solar Electric Technology, Inglewood, CA (USA))

1991-04-01

80

High mobility transparent conducting oxides for thin film solar cells  

International Nuclear Information System (INIS)

A special class of transparent conducting oxides (TCO) with high mobility of > 65 cm2 V-1 s-1 allows film resistivity in the low 10-4 ? cm range and a high transparency of > 80% over a wide spectrum, from 300 nm to beyond 1500 nm. This exceptional coincidence of desirable optical and electrical properties provides opportunities to improve the performance of opto-electronic devices and opens possibilities for new applications. Strategies to attain high mobility (HM) TCO materials as well as the current status of such materials based on indium and cadmium containing oxides are presented. Various concepts used to understand the underlying mechanisms for high mobility in HMTCO films are discussed. Examples of HMTCO layers used as transparent electrodes in thin film solar cells are used to illustrate possible improvements in solar cell performance. Finally, challenges and prospects for further development of HMTCO materials are discussed.

2010-01-31

 
 
 
 
81

Multi-plasmon enhancement of thin film organic solar cells  

Energy Technology Data Exchange (ETDEWEB)

A theoretical, two-dimensional (2D), periodic nano-structured design for thin film organic solar cells is presented. In this design the superposition of two periodic silver plasmonic gratings is seen to strongly increase the absorptive dissipation around two selectable wavelengths in the sub bandgap region. Finite-difference time domain (FDTD) calculations were found to be comparable to analytical predictions of the plasmon dispersion relation for the system which were calculated with an averaged dielectric permittivity. A method for tuning the strength of the generated plasmons is demonstrated by controlling the ratio of silver to active material within the grating layer. Profile cross-sections illustrate areas of the active layer exhibiting an increase of 40 times the absorptive dissipation compared to a non-grating cell structure. The areas of strongest increase in absorptive dissipation are visible next to the cell exit interfaces, as desired for a reduction in recombination losses.

Williamson, Adam; Runge, Erich [Institut fuer Physik und Institut fuer Mikro- und Nanotechnologien, Technische Universitaet Ilmenau (Germany); McClean, Eadaoin; Zerulla, Dominic [University College Dublin (Ireland)

2011-07-01

82

Boron-doped nanocrystalline silicon thin films for solar cells  

International Nuclear Information System (INIS)

This article reports on the structural, electronic, and optical properties of boron-doped hydrogenated nanocrystalline silicon (nc-Si:H) thin films. The films were deposited by plasma-enhanced chemical vapour deposition (PECVD) at a substrate temperature of 150 deg. C. Crystalline volume fraction and dark conductivity of the films were determined as a function of trimethylboron-to-silane flow ratio. Optical constants of doped and undoped nc-Si:H were obtained from transmission and reflection spectra. By employing p+ nc-Si:H as a window layer combined with a p' a-SiC buffer layer, a-Si:H-based p-p'-i-n solar cells on ZnO:Al-coated glass substrates were fabricated. Device characteristics were obtained from current-voltage and spectral-response measurements.

2011-08-15

83

Cuinse2 Thin Film For Solar Cell By Flash Evaporation  

Directory of Open Access Journals (Sweden)

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 20C-415C.

A.H. Soepardjo

2009-01-01

84

Thin-film solar cells on commercial ceramic tiles  

Energy Technology Data Exchange (ETDEWEB)

Amorphous silicon solar cells were deposited on porcelain stoneware tiles in order to develop a fully integrated PV building element. In a previous work we demonstrated the feasibility of adopting porcelain stoneware tiles as thin-film solar cell substrates and we fabricated 1 x 1cm{sup 2} solar cells on ''industrial-level'' ceramic substrates showing more than 4% efficiency. In this study we focus our attention on larger area (7cm{sup 2}) devices deposited on 100cm{sup 2} tiles. As the active area increases additional problems arise from the surface of the substrate. In particular we find that short-circuit paths originate from the unfavorable properties of the substrate tiles (roughness, porosity, etc.) having dramatic consequences on the performance of larger area devices. With the assumption that spot-like regions, in which the back layer and the front layer are in electrical contact (local short-circuits), are present all over the device, we propose a new device structure to overcome the substrate drawbacks. A new contacts arrangement was designed in order to minimize the shunting effect of short-circuit paths. As a result an initial efficiency of 2.5% has been obtained using the new device structure for 7cm{sup 2} devices deposited on a 100cm{sup 2} PV mini-module tile. (author)

Iencinella, Daniele; Centurioni, Emanuele; Grazia Busana, Maria [CNR-IMM Bologna, Via P. Gobetti 101, 40129, Bologna (Italy)

2009-02-15

85

Perspectives of crystalline Si thin film solar cells: a new era of thin monocrystalline Si films?  

Energy Technology Data Exchange (ETDEWEB)

A large number of competing approaches are currently being investigated around the world to develop crystalline silicon thin film solar cells on foreign substrates. These approaches can be broadly classified according to the crystalline state of the Si films employed: (i) thin film solar cells based on nano- or microcrystalline Si-films; (ii) cells fabricated from large-grained polycrystalline Si and (iii) recent approaches utilising the transfer of monocrystalline Si films. The paper discusses prospects and limitations of these approaches and describes device results based on the transfer of quasi-monocrystalline Si films. Using Si absorber films epitaxially grown on quasi-monocrystalline Si, we achieve a conversion efficiency of 13.6% for a 4 cm{sup 2} sized thin film solar cell on glass. In contrast to the limited performance of polycrystalline Si thin film solar cells imposed by the presence of grain boundaries, transfer approaches are expected to result in thin film solar cells imposed by the presence of grain boundaries, transfer approaches are expected to result in thin film solar cell efficiencies in the range of 15-18% depending on process maturity and complexity. The transfer of monocrystalline Si films therefore opens a new avenue to an efficient and competitive Si-based thin film technology. (Author)

Bergmann, Ralf B.; Rinke, Titus J. [Stuttgart Univ., Inst. of Physical Electronics, Stuttgart (Germany)

2000-07-01

86

High-efficiency copper ternary thin film solar cells  

Energy Technology Data Exchange (ETDEWEB)

This report describes a project to develop a high efficiency thin film CuInSe{sub 2} solar cell using a low-cost process. The two-stage process involves depositing the metallic elements of Cu and In on a substrate in the form of stacked layers, and then selenizing this stacked metallic film in an atmosphere containing Se. Early research concentrated on the electrodeposition technique for depositing the Cu and In films on Mo-coated glass substrates. This resulted in small-area cells with around 10% efficiency, indicating that the technique could yield CuInSe{sub 2} films with good electrical and optical properties. The program then involved scaling up the electrodeposition/selenization technique; fixtures for large-area plating were designed and built, but poor adhesion of the CuInSe{sub 2} films to the Mo-coated substrates and the stoichiometric non-uniformities encountered in the large-area films hindered the efficiency of the devices. The latter part of the program explored a new approach to the two-stage process. An evaporation/selenization approach, where the elemental layers were evaporated onto the Mo-coated substrates for selenization. Solar cells have been produced with efficiencies approaching 11% using E-beam evaporated/selenized CuInSe{sub 2} films. 9 refs., 14 figs., 2 tabs.

Kapur, V.K.; Basol, B.M.; Kullberg, R.C. (International Solar Electric Technology, Inglewood, CA (USA))

1989-09-01

87

Thin film transistors and solar cells. (Latest citations from the US Patent bibliographic file with exemplary claims). Published Search  

Energy Technology Data Exchange (ETDEWEB)

The bibliography contains citations of selected patents concerning the fabrication and application methods of thin film transistors and thin film solar cells. Methods of manufacturing thin film transistors for use in electronic display devices are presented. Techniques for continuously producing durable and reliable thin film solar cells are discussed. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

NONE

1996-04-01

88

Pulsed electrically detected magnetic resonance for thin film silicon and organic solar cells.  

Science.gov (United States)

In thin film solar cells based on non-crystalline thin film silicon or organic semiconductors structural disorder leads to localized states that induce device limiting charge recombination and trapping. Both processes frequently involve paramagnetic states and become spin-dependent. In the present perspectives article we report on advanced pulsed electrically detected magnetic resonance (pEDMR) experiments for the study of spin dependent transport processes in fully processed thin film solar cells. We reflect on recent advances in pEDMR spectroscopy and demonstrate its capabilities on two different state of the art thin film solar cell concepts based on microcrystalline silicon and organic MEH-PPV:PCBM blends, recently studied at HZB. Benefiting from the increased capabilities of novel pEDMR detection schemes we were able to ascertain spin-dependent transport processes and microscopically identify paramagnetic states and their role in the charge collection mechanism of solar cells. PMID:22941053

Schnegg, Alexander; Behrends, Jan; Fehr, Matthias; Lips, Klaus

2012-08-31

89

Pulsed electrically detected magnetic resonance for thin film silicon and organic solar cells.  

UK PubMed Central (United Kingdom)

In thin film solar cells based on non-crystalline thin film silicon or organic semiconductors structural disorder leads to localized states that induce device limiting charge recombination and trapping. Both processes frequently involve paramagnetic states and become spin-dependent. In the present perspectives article we report on advanced pulsed electrically detected magnetic resonance (pEDMR) experiments for the study of spin dependent transport processes in fully processed thin film solar cells. We reflect on recent advances in pEDMR spectroscopy and demonstrate its capabilities on two different state of the art thin film solar cell concepts based on microcrystalline silicon and organic MEH-PPV:PCBM blends, recently studied at HZB. Benefiting from the increased capabilities of novel pEDMR detection schemes we were able to ascertain spin-dependent transport processes and microscopically identify paramagnetic states and their role in the charge collection mechanism of solar cells.

Schnegg A; Behrends J; Fehr M; Lips K

2012-11-01

90

Characterization of ZnO:Ga transparent contact electrodes for microcrystalline silicon thin film solar cells  

Energy Technology Data Exchange (ETDEWEB)

Gallium-doped zinc oxide (ZnO:Ga) thin films are of interest to the semiconductor industry as transparent conductive surfaces and as transparent contact electrode layers for applications such as microcrystalline silicon ({mu}c-Si) thin film solar cells. Physical vapor deposition (PVD) via sputtering is commonly used to produce thin films such as ZnO:Ga, but film quality and characteristics depend significantly on the PVD processing parameters. For use as contact electrode layers in {mu}c-Si thin film solar cells, this study investigates some of the important changes of ZnO:Ga thin films that result from varying DC magnetron PVD sputtering parameters, specifically the working power (500, 1200, and 1900 w), process gas (Ar, Ar/O{sub 2}=50/0.2 sccm) and working pressure (0.74 and 1.06 Pa). Process temperature is held at 200 C because thin film solar cells are damaged above 200 C. Adding O{sub 2} to the Ar carrier gas improved transmittance but the resistivity suffered. However, high-sputtering power solved the resistivity problem. Additionally, the effects of the produced ZnO:Ga material when applied as multi-layer front and back layer electrodes to {mu}c-Si thin film solar cells is evaluated in terms of open-circuit voltage ({delta}V{sub OC}), short-circuit current density ({delta}J{sub SC}), fill factor ({delta}FF) and efficiency ({delta}{eta}) of the cells. (author)

Lai, Kuang-Chieh; Houng, Mau-Phon [Institute of Microelectronics, Department of Electrical Engineering, National Cheng Kung University, No.1, Dasyue Rd., East District, Tainan City 701 (China); Liu, Chien-Chih [Department of Electrical Engineering, Nan Jeon Institute of Technology, Tainan County 737 (China); Lu, Chun-hsiung; Yeh, Chih-Hung [NexPower Technology Corporation, Taichung County 421 (China)

2010-03-15

91

Environmental influences on the performance of thin film solar cells  

International Nuclear Information System (INIS)

The response of thin film photovoltaic devices to changes in the environment is not well understood. There are a large number of conflicting reports, reflecting largely the superimposed nature of the environmental effects. A separation of the effects is not often attempted mainly because of the lack of appropriate spectral data. An experimental system has been designed and operated to facilitate the separation of the environmental effects, including spectral effects. This involves measurements in a controlled laboratory environment as well as outdoor monitoring. Furthermore, a number of analysis tools have been developed and tested for their suitability. In order to develop a system model, the applicability of parametric models for thin film devices is probed. The thermal variation of the underlying physical parameters is investigated and problems of describing thin film devices with parametric models are discussed. It is shown that the magnitude of the spectral effects for thin film devices is potentially much more significant than for conventional crystalline silicon devices. This analysis is centred on the primary spectral effect, i.e. it is conducted purely on the basis of available light and does not consider any absorption profiles or device structures. It is also shown that there is a strong daily and seasonal variation in the fraction of the useful light for devices employing a larger band gap. Environmental effects are observed directly from outdoor measurements. It is apparent that many of the reported idiosyncrasies occurring during the operation of thin film devices can be explained simply by including spectral effects. It is possible to show the secondary spectral effect for multi-junction devices, i.e. an effect that depends on the composition of the solar irradiance and not purely on the magnitude of spectrally useful irradiance. This effect impacts mainly on the short circuit current and to some extent on the fill factor. Finally, the findings of this work are brought together in a simulation code for thin film photovoltaic devices. It is shown that it is possible to simulate such a photovoltaic system using parametric models, as long as the spectrum is considered. This is used to investigate the operational losses for one particular device. (author)

2001-01-01

92

Zone-Melting Recrystallization for Crystalline Silicon Thin-Film Solar Cells  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Thin-film solar cells from crystalline silicon require only a fraction of the high purity absorber material needed for wafer based solar cells. Due to the crystalline structure, the silicon film can be processed into solar cells analogous to multicrystalline silicon wafers - and the cells can reach ...

Kieliba, Thomas

93

The Cu2ZnSnSe4 thin films solar cells synthesized by electrodeposition route  

Science.gov (United States)

An electrodeposition route for preparing Cu2ZnSnSe4 thin films for thin film solar cell absorber layers is demonstrated. The Cu2ZnSnSe4 thin films are prepared by co-electrodeposition Cu-Zn-Sn metallic precursor and subsequently annealing in element selenium atmosphere. The structure, composition and optical properties of the films were investigated by X-ray diffraction (XRD), Raman spectrometry, energy dispersive spectrometry (EDS) and UV-VIS absorption spectroscopy. The Cu2ZnSnSe4 thin film with high crystalline quality was obtained, the band gap and absorption coefficient were 1.0 eV and 10-4 cm-1, which is quite suitable for solar cells fabrication. A solar cell with the structure of ZnO:Al/i-ZnO/CdS/Cu2ZnSnSe4/Mo/glass was fabricated and achieved an conversion efficiency of 1.7%.

Li, Ji; Ma, Tuteng; Wei, Ming; Liu, Weifeng; Jiang, Guoshun; Zhu, Changfei

2012-06-01

94

Molybdenum Back-Contact Optimization for CIGS Thin Film Solar Cell  

Directory of Open Access Journals (Sweden)

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.

J.R. Ray; N.M. Shah; M.S. Desai; C.J. Panchal

2011-01-01

95

Thin-film solar cells. Technology evaluation and perspectives  

Energy Technology Data Exchange (ETDEWEB)

The main thin-film solar cell technologies are evaluated with respect to the criteria Cost, Applicability, Sustainability and Compatibility with the Dutch PV infrastructure. This evaluation concerns the following technologies in particular: thin film crystalline silicon, separated into low and high temperature deposition processes (LT-f-Si, HT-f-Si), amorphous silicon (a-(Si,Ge):H), copper indium-gallium di-selenide-sulphide (CIGS), cadmium telluride (CdTe) and dye-sensitized (DSC) solar cells technologies. For this evaluation, multicrystalline silicon (mc-Si) is used as a reference. This means that all scores (low, high, etc.) are relative to mc-Si. Organic/polymeric cells are of special interest for the long term, but not enough data is available for a full analysis. Interviews with experts from industry and R and D institutions and a technology review form the basis for this evaluation. The present status, the short- and long-term perspective are reviewed and the risk involved in the further developments is assessed, the risk being separately evaluated and weighed. To facilitate comparison the criteria are quantified and weighing factors are used to normalise the evaluation. Where possible, the developments and data reflect the expected status in 2005. A number of interesting patterns can be observed from this evaluation. In the category Cost, a-(Si,Ge):H, LT-f-Si and DSC score better than mc-Si. In the category Applicability, a-(Si,Ge):H, and to a lesser extent CIGS and CdTe, score high. LT-f-Si scores high for Sustainability, both for its low toxicity content and a high resource availability. CIGS, CdTe and HT-f-Si score low in the category Cost, Sustainability and Dutch infrastructure. As expected, only the a-(Si,Ge):H technology scores well on the availability of a good PV R and D infrastructure in The Netherlands. DSC scores relatively high on the R and D infrastructure, where especially the international technological position is excellent. Industrial activities world-wide are concentrated on high-rate and low-cost manufacturing processes. At present industry is investing mainly in the x-Si, a-(Si,Ge):H, CIGS and CdTe technologies. R and D is focused on improving efficiency, gaining a thorough understanding of the material properties and developing new deposition techniques. The interviews with experts indicate confidence in x-Si and a-(Si,Ge):H technologies with regard to the criteria Costs, Efficiency and Risk control. The technology mapping confirms these expectations. A major difficulty in scaling up the CIGS and CdTe technologies is the control of active layer deposition over a large area. The critical risks involved in processing LT-f-Si technologies are the deposition of the active layer and control of the material properties. The a-(Si,Ge):H and LT-f-Si are strongly related and it is expected that they can benefit from each other, with mutual spin-off and probably combined devices. HT-f-Si has a potential for high efficiencies, but the development time is still long and no real successful deposition process has been identified yet, so the level of uncertainty is high. It is anticipated that the dye-sensitised and the organic/polymeric solar cells will become important in the mid- to longer term with advantages in Costs and Applicability. Much basic and applied research has yet to be done on the stability for both types and the charge transport properties of organic/polymeric materials. During the interviews, several experts mentioned that more co-operation between research groups and the industry is important on a European and intercontinental level. 97 refs.

Tool, C.J.J.; Roosmalen, J.A.M.; Wentink, C.H.M. [ECN Solar Energy, Petten (Netherlands); Bossert, R.H.; De Vaan, M.J.M. [Berenschot BV, Utrecht (Netherlands)

2000-05-01

96

Polycrystalline silicon thin-film solar cell prepared by the solid phase crystallization (SPC) method  

Energy Technology Data Exchange (ETDEWEB)

A solid phase crystallization (SPC) method was applied to the fabrication of thin-film polycrystalline silicon (poly-Si) for solar cells for the first time. Among crystalline silicon solar cells crystallized at a low temperature of less than 600 C, the world`s highest conversion efficiency of 8.5% was achieved in a solar cell using thin-film poly-Si with only 10 {micro}m thickness prepared by the SPC method. This solar cell showed high photosensitivity in the long-wavelength region of more than 800 nm and also exhibited no light-induced degradation after light exposure.

Baba, T.; Matsuyama, T.; Sawada, T.; Takahama, T.; Wakisaka, K.; Tsuda, S.; Nakano, S. [Sanyo Electric Co., Ltd., Hirakata, Osaka (Japan). New Materials Research Center

1994-12-31

97

SnS thin film solar cells with Zn1-xMgxO buffer layers  

Science.gov (United States)

The conduction band offset (CBO) of SnS as the light absorbing layer and Zn1-xMgxO as the buffer layer in SnS thin film solar cells has been optimized to improve the solar cell conversion efficiency. We controlled the CBO experimentally by varying the Mg content (x) of the Zn1-xMgxO layer. The optimum CBO value range for improved solar cell performance was determined to be from -0.1 to 0 eV. A SnS thin film solar cell sample with the optimum CBO value exhibited conversion efficiency of approximately 2.1%.

Ikuno, Takashi; Suzuki, Ryo; Kitazumi, Kosuke; Takahashi, Naoko; Kato, Naohiko; Higuchi, Kazuo

2013-05-01

98

Lead antimony sulfides as potential solar absorbers for thin film solar cells  

Energy Technology Data Exchange (ETDEWEB)

The synthesis of thin film was described along with the electronic and optical characteristics of many lead antimony sulfide films. Direct band gap semiconductors which strongly absorb light, such as CuInS{sub 2}, Cu(In,Ga)Se{sub 2} and CdTe, are promising substitutes for silicon as light absorber materials for photovoltaic cells. Although their efficiencies are excellent, availability of indium (In) and tellurium (Te) may limit the size of the photovoltaic cell that can be commercialized using current leading thin film technologies. In addition, the toxicity of cadmium poses environmental challenges if widely produced. For these reasons, this study focused on developing new thin film device configurations based only on cost effective, abundant, and less toxic materials. Most lead antimony sulfides are potential solar absorbers since they have band gaps with values between 1.3 and 1.7 eV. The thin films included Pb{sub 3}Sb{sub 8}S{sub 15}, Pb{sub 7}Sb{sub 8}S{sub 19}, Pb{sub 9}Sb{sub 8}S{sub 21} and Pb{sub 5}Sb-8S{sub 17}. The unique synthesis of smooth and compact thin films of the above phases were described. The films were synthesized as potential new light absorbers for thin film solar cells via sulfurization of amorphous and crystalline lead sulfide (PbS) layered precursor films, obtained from sputtering of Sb{sub 2}S{sub 3} and Pb targets. The films exhibited suitable band gaps and encouraging electrical properties. 4 refs,.

Versavel, M.Y.; Haber, J.A. [Alberta Univ., Edmonton, AB (Canada). Dept. of Chemistry

2006-07-01

99

Lead antimony sulfides as potential solar absorbers for thin-film solar cells  

Energy Technology Data Exchange (ETDEWEB)

Most lead antimony sulphides have suitable optical band gaps for thin film photovoltaic applications. This thesis described the synthesis of new semiconductor thin films that contain only cost effective, abundant, and low toxicity materials. In particular, it described the optical characterization of several lead antimony sulphide films as potential light absorbers for thin film solar cells and the efforts to examine the Hf-Zr-Sb phase diagram. The preparation of amorphous and polycrystalline antimony sulphide thin films from RF-sputtering of an Sb{sub 2}S{sub 3} target and subsequent annealing at 400 degrees C in sulphur vapor yielded smooth and compact semiconductor thin films. Sputtered metallic Pb-Sb precursor films were annealed in sulphur vapor in order to prepare polycrystalline films of lead antimony sulphides. Since the initial formation of PbS is not good for product film morphology, a more successful approach was developed in which sulphur-containing precursor films composed of crystalline PbS were reacted with amorphous (Sb,S) layers prepared by cycled sputtering of Sb{sub 2}S{sub 3} and Pb under sulphur vapor. The synthesized films were metastable since films of the plagionite group phases were preferentially obtained, and hydrogen was not necessary. Sulphurization of the unique crystalline PbS and amorphous layered precursor films yielded smooth, continuous and phase-pure films of the 4 plagionite group phases with good optical properties.

Versavel, M.

2008-07-01

100

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)

1999-01-01

 
 
 
 
101

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Zhang, Zhenhao

102

Hydrogen passivation of polycrystalline Si thin film solar cells  

International Nuclear Information System (INIS)

[en]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.)

2010-01-01

103

Enhanced efficiency of light-trapping nanoantenna arrays for thin-film solar cells  

Science.gov (United States)

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.

Simovski, Constantin; Morits, Dmitry; Voroshilov, Pavel; Guzhva, Michael; Belov, Pavel; Kivshar, Yuri

2013-07-01

104

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

CERN Multimedia

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.

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

2013-01-01

105

Light trapping in periodically textured amorphous silicon thin film solar cells using realistic interface morphologies.  

UK PubMed Central (United Kingdom)

The influence of realistic interface morphologies on light trapping in amorphous silicon thin-film solar cells with periodic surface textures is studied. Realistic interface morphologies are obtained by a 3D surface coverage algorithm using the substrate morphology and layer thicknesses as input parameters. Finite difference time domain optical simulations are used to determine the absorption in the individual layers of the thin-film solar cell. The influence of realistic interface morphologies on light trapping is determined by using solar cells structures with the same front and back contact morphologies as a reference. Finally the optimal surface textures are derived.

Jovanov V; Palanchoke U; Magnus P; Stiebig H; Hpkes J; Sichanugrist P; Konagai M; Wiesendanger S; Rockstuhl C; Knipp D

2013-07-01

106

Soft elastomeric nanopillar stamps for enhancing absorption in organic thin-film solar cells.  

Science.gov (United States)

An elastomeric poly(dimethylsiloxane) (PDMS) block engraved with periodically arrayed nanopillars serves as a transferable light-trapping stamp for encapsulated organic thin-film solar cells. Diffracted light rays from the stamp interfere with one another and self-focus onto the active layer of the solar cell, generating enhanced absorption, as indicated in the current density-voltage measurements. PMID:23047618

Hyun, Jerome K; Ahn, Changui; Kang, Hyunbum; Kim, Hyeong Jun; Park, Junyong; Kim, Ki-Hyun; Ahn, Chi Won; Kim, Bumjoon J; Jeon, Seokwoo

2012-10-09

107

High-temperature CVD silicon films for crystalline silicon thin-film solar cells  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The deposition of silicon layers plays a central role within the approach of crystalline silicon thin-film solar cells. The introduction of this solar cell type into industrial production lines requires the development of Si-deposition systems which are capable to meet the demands on low cost and hi...

Bau, Sandra

108

Design and non-lithographic fabrication of light trapping structures for thin film silicon solar cells  

Energy Technology Data Exchange (ETDEWEB)

A self-assembled light trapping structure is numerically designed on the backside of thin film silicon solar cells and fabricated by using porous alumina as a template. We demonstrate this structure can effectively increase the optical absorption and thus improve the solar cell performances. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Sheng, Xing; Liu, Jifeng; Agarwal, Anuradha M.; Michel, Jurgen; Kimerling, Lionel C. [Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Kozinsky, Inna [Robert Bosch LLC, Research and Technology Center, Palo Alto, CA 94304 (United States)

2011-02-15

109

Soft elastomeric nanopillar stamps for enhancing absorption in organic thin-film solar cells.  

UK PubMed Central (United Kingdom)

An elastomeric poly(dimethylsiloxane) (PDMS) block engraved with periodically arrayed nanopillars serves as a transferable light-trapping stamp for encapsulated organic thin-film solar cells. Diffracted light rays from the stamp interfere with one another and self-focus onto the active layer of the solar cell, generating enhanced absorption, as indicated in the current density-voltage measurements.

Hyun JK; Ahn C; Kang H; Kim HJ; Park J; Kim KH; Ahn CW; Kim BJ; Jeon S

2013-02-01

110

Electrical Conductivity of Chlorophyll with Polythiophene Thin Film on Indium Tin Oxide as P-N Heterojunction Solar Cell  

Directory of Open Access Journals (Sweden)

Full Text Available This work was focused on the study of electrical conductivity to the combination of Polythiophene (PT) thin film and Chlorophyll (CHLO) thin film by layered on Indium Tin Oxide (ITO) substrate as p-n heterojunction solar cell. PT thin film is deposited to the ITO substrate by using electrochemistry method. CHLO thin film is coated on PT thin film by using the spin coating method. Current and voltage of ITO/PT/CHLO thin film are measured in the dark and under different light intensity by using the four point probes. The results showed that PT thin film was successfully coated with CHLO on ITO substrate with different thicknesses. Electrical conductivity in the dark showed an increasing with the increasing of PT thin film thickness. While with the increasing of CHLO thin film thickness, electrical conductivity in the dark is consecutively changed. Electrical conductivity under different intensity of light increased with the increasing of light intensity. Electrical conductivity under intensity of light are diminished with the increasing of PT thin film thickness while electrical conductivity is increased with the increasing of the light intensity and the increasing of CHLO thin film thickness. In conclusion, combination of the thinnest PT with the thickest CHLO thin film produced the highest electrical conductivity reach up to 0.1 Sm1 (raise 22% under illumination compared to the electrical conductivity in the dark condition). This study is suitable to generate a solar cell.

S. Hasiah; K. Ibrahim; H.B. Senin; K.B.K. Halim

2008-01-01

111

Effects of Cd-free buffer layer for CuInSe{sub 2} thin-film solar cells  

Energy Technology Data Exchange (ETDEWEB)

ZnO buffer layer by a chemical-bath deposition (CBD) method is developed in this study to improve the interface quality between n-ZnO window layer and p-CuInSe{sub 2} (CIS) thin-film absorber in CIS thin-film solar cells as one of the approaches to the fabrication of Cd-free thin-film solar cells. The optimization of the fabrication conditions of CBD-ZnO leads to the efficiency of about 10%. These results indicate the CBD-ZnO buffer layer has rather high capability to fabricate high-efficiency CIS thin-film solar cells.

Nii, T.; Sugiyama, I.; Kase, T.; Sato, M.; Kaniyama, Y.; Kuriyagawa, S.; Kushiya, K.; Takeshita, H. [Showa Shell Sekiyu K.K., Atsugi, Kanagawa (Japan). Central R and D Lab.

1994-12-31

112

Absorption efficiency enhancement in inorganic and organic thin film solar cells via plasmonic honeycomb nanoantenna arrays.  

UK PubMed Central (United Kingdom)

We demonstrate theoretically that by embedding plasmonic honeycomb nanoantenna arrays into the active layers of inorganic (c-Si) and organic (P3HT:PCBM/PEDOT:PSS) thin film solar cells, absorption efficiency can be improved. To obtain the solar cell absorption spectrum that conforms to the solar radiation, spectral broadening is achieved by breaking the symmetry within the Wigner-Seitz unit cell on a uniform hexagonal grid. For optimized honeycomb designs, absorption efficiency enhancements of 106.2% and 20.8% are achieved for c-Si and P3HT:PCBM/PEDOT:PSS thin film solar cells, respectively. We have demonstrated that the transverse modes are responsible for the enhancement in c-Si solar cells, whereas both the longitudinal and transverse modes, albeit weaker, are the main enhancement mechanisms for P3HT:PCBM/PEDOT:PSS solar cells. For both inorganic and organic solar cells, the absorption enhancement is independent of polarization.

Tok RU; Sendur K

2013-08-01

113

Absorption efficiency enhancement in inorganic and organic thin film solar cells via plasmonic honeycomb nanoantenna arrays.  

Science.gov (United States)

We demonstrate theoretically that by embedding plasmonic honeycomb nanoantenna arrays into the active layers of inorganic (c-Si) and organic (P3HT:PCBM/PEDOT:PSS) thin film solar cells, absorption efficiency can be improved. To obtain the solar cell absorption spectrum that conforms to the solar radiation, spectral broadening is achieved by breaking the symmetry within the Wigner-Seitz unit cell on a uniform hexagonal grid. For optimized honeycomb designs, absorption efficiency enhancements of 106.2% and 20.8% are achieved for c-Si and P3HT:PCBM/PEDOT:PSS thin film solar cells, respectively. We have demonstrated that the transverse modes are responsible for the enhancement in c-Si solar cells, whereas both the longitudinal and transverse modes, albeit weaker, are the main enhancement mechanisms for P3HT:PCBM/PEDOT:PSS solar cells. For both inorganic and organic solar cells, the absorption enhancement is independent of polarization. PMID:24104664

Tok, R?t Umut; Sendur, Kr?at

2013-08-15

114

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

Energy Technology Data Exchange (ETDEWEB)

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.)

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

115

On Generation and Recombination in Cu(In,Ga)Se2 Thin-Film Solar Cells  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The solar cell technology based on Cu(In,Ga)Se2 (CIGS) thin-films provides a promising route to cost competitive solar electricity. The standard device structure is ZnO:Al/ZnO/CdS/CIGS/Mo films on a glass substrate, where the first three layers are n-type semiconductors with wide bandgaps, forming a...

Malmstrm, Jonas

116

Progress in Polycrystalline Thin-Film Solar Cells.  

Science.gov (United States)

Photovoltaic devices based on several polycrystalline thin-film materials have reached near and above 10% sunlight-to-electricity conversion efficiencies. This paper examines the various polycrystalline thin-film PV materials including CuInSe sub 2 and Cd...

K. Zweibel A. Hermann R. Mitchell

1983-01-01

117

Hydrogen passivation of polycrystalline Si thin film solar cells  

Energy Technology Data Exchange (ETDEWEB)

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.)

Gorka, Benjamin

2010-12-15

118

Engineering Gaussian disorder at rough interfaces for light trapping in thin-film solar cells.  

Science.gov (United States)

A theoretical study of randomly rough interfaces to obtain light trapping in thin-film silicon solar cells is presented. Roughness is modeled as a surface with Gaussian disorder, described using the root mean square of height and the lateral correlation length as statistical parameters. The model is shown to describe commonly used rough substrates. Rigorous calculations, with short-circuit current density as a figure of merit, lead to an optimization of disorder parameters and to a significant absorption enhancement. The understanding and optimization of disorder is believed to be of general interest for various realizations of thin-film solar cells. PMID:23202073

Kowalczewski, Piotr; Liscidini, Marco; Andreani, Lucio Claudio

2012-12-01

119

Engineering Gaussian disorder at rough interfaces for light trapping in thin-film solar cells.  

UK PubMed Central (United Kingdom)

A theoretical study of randomly rough interfaces to obtain light trapping in thin-film silicon solar cells is presented. Roughness is modeled as a surface with Gaussian disorder, described using the root mean square of height and the lateral correlation length as statistical parameters. The model is shown to describe commonly used rough substrates. Rigorous calculations, with short-circuit current density as a figure of merit, lead to an optimization of disorder parameters and to a significant absorption enhancement. The understanding and optimization of disorder is believed to be of general interest for various realizations of thin-film solar cells.

Kowalczewski P; Liscidini M; Andreani LC

2012-12-01

120

Indium phosphide/cadmium sulfide thin-film solar cells  

Energy Technology Data Exchange (ETDEWEB)

Thin-film InP/CdS structures were prepared by depositing, in sequence, ITO on a low-cost glass substrate, CdS on the ITO by thermal evaporation, and InP on the CdS by planar reactive deposition (PRD). Films of CdS, 15 ..mu..m thick, were recrystallized in flowing H/sub 2//H/sub 2/S at 500/sup 0/C. Lateral dimensions of typical grains were 50..mu..m with values up to 200 ..mu..m. The sheet resistance of the recrystallized CdS (RXCdS) was lowered from greater than 10/sup 5/ ..cap omega../O = cm/sup 2/ to values as low as 16 ..cap omega../O = cm/sup 2/ by annealing in either H/sub 2/ Cd atmospheres. Epitaxy of InP was undertaken on (100) InP at a substrate temperature of 320/sup 0/C. Room-temperature electron mobilities of about 2000 cm/sup 2//V-sec were found. Mobilities and hole concentrations of 60 cm/sup 2//V-sec and 10/sup 17/ cm-/sup 3/, respectively, were achieved with Be-doped films. P-type films with hole concentrations as high as a few times 10/sup 18/cm-/sup 3/ were achieved with increased doping. Be-doped InP was deposited onto the RXCdS/ITO/GLASS substrate to form a thin-film cell. However, p-type InP could not be prepared with CdS as a substrat4e, presumably due to interdiffusion or vapor transport of sulfur. Consequently, blocking action and a photovoltage could only be achieved using a gold Schottky barrier on the InP/RXCdS/ITO/GLASS structure. Plans for the next quarter include determining whether n-type doping from the CdS occurs by either interdiffusion or vapor transport, characterizing InP epitaxy on the RXCdS, and preparing additional thin-film structures.

Zanio, K.

1980-02-01

 
 
 
 
121

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

Energy Technology Data Exchange (ETDEWEB)

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.'

2012-09-01

122

Device design of thin film solar cells; Usumaku taiyo denchi no device sekkei  

Energy Technology Data Exchange (ETDEWEB)

From the viewpoint of global environmental protection, it is expected that photovoltaic power generation is propagated on a full scale. Thin film solar cells have been actively developed, for cost reduction indispensable to real propagation, as the successor of bulk crystalline Si solar cells that are the mainstream of the photovoltaic market today. This paper gives the technological outline of thin film solar cells, especially, amorphous thin film solar cells and describes the device design from the standpoint of the improvement in power generation performance and cost competitiveness. In the amorphous thin film solar cells, light containment technology is important. Therefore, the structure must be designed so that the texture on the plane of incidence reduces the reflection rate and simultaneously effectively increases the optical path length of incident light. The module temperature of solar cells may rise up to 60 through 80degC in the condition where they are used outdoors. This causes the decrease in a release voltage and the deterioration in characteristics. Therefore, the use of a-Si:H rather than of a-SiGe:H improves the power generation performance. 9 refs., 7 figs.

Nomoto, K.; Taniguchi, H.; Sannomiya, H.; Hayakawa, T. [Sharp Corp., Osaka (Japan)

1998-04-10

123

Improved Transparent Conducting Oxides Boost Performance of Thin-Film Solar Cells (Fact Sheet)  

Energy Technology Data Exchange (ETDEWEB)

Today?s thin-film solar cells could not function without transparent conducting oxides (TCOs). TCOs act as a window, both protecting the cell and allowing light to pass through to the cell?s active layers. Until recently, TCOs were seen as a necessary, but static, layer of a thin-film photovoltaic (PV) cell. But a group of researchers at the National Renewable Energy Laboratory (NREL) has identified a pathway to producing improved TCO films that demonstrate higher infrared transparency. To do so, they have modified the TCOs in ways that did not seem possible a few years ago.

2011-02-01

124

Photocapacitance and current collection in CdS/CdTe thin-film solar cells  

Energy Technology Data Exchange (ETDEWEB)

A large photocapacitance is observed in CdS/CdTe thin-film solar cells. A Schottky-barrier solar cell containing deep levels within the bulk was considered, and the dependence of photocapacitance on defect energy level, capture cross section, defect concentration, and light intensity was calculated. Predictions of the model with parameters appropriate for the CdS/CdTe solar cell and information on deep levels obtained from DLTS agreed with experiment.

Isett, L.C.

1984-05-01

125

Thin films of cadmium telluride produced using stacked elemental layer (SEL) processing for use in thin film solar cells  

Energy Technology Data Exchange (ETDEWEB)

The stacked elemental layer (SEL) technique has been used to synthesise thin films of CdTe. This technique consists of depositing alternate layers of Cd/Te in the stoichiometric ratio and then anneraling the stack to react the layers to form the compound. The Cd and Te layers were deposited using thermal evaporation and annealed in nitrogen, vacuum or air. Transmittance and reflectance data, X-ray diffraction data and scanning electron microscopy observations of the surface topology are given for the layers produced. Post synthesis annealing of the layers using CuCl[sub 2]/CdCl[sub 2]/methanol was also investigated. This was found to substantially increase the grain size of the layers produced. This process promises to be a low cost method for producing large areas suitable for use in solar cell structures. A preliminary energy analysis has been carried out and energy payback times and energy ratios are presented. (author)

Bhatti, M.T.; Hynes, K.M.; Miles, R.W.; Hill, R. (Newcastle upon Tyne Polytechnic (United Kingdom))

1992-01-01

126

Thin film solar cells on the basis of n-CdS-?CdTe heterostructures  

International Nuclear Information System (INIS)

The results of preparation and investigation of photoelectric properties investigations of thin film solar cells on the basis of n-CdS-?CdTe heterostructures are given. It is shown that the obtained cells have sufficiently high effectiveness - 9,6%.

2000-01-01

127

Effect of Gaussian doping profile on the performance of a thin film polycrystalline solar cell  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A two-dimensional (2D) analytical model based on the Greens function method is applied to an n+-p thin film polycrystalline solar cell that allows us to calculate the conversion efficiency. This model considers the effective Gaussian doping profile in the p region in order to improve cell efficien...

Kolsi S.; Ben Amar M.; Samet H.; Ouali A.

128

Fabrication of nanocrystal ink based superstrate-type CuInS? thin film solar cells.  

UK PubMed Central (United Kingdom)

A CuInS? (CIS) nanocrystal ink was applied to thin film solar cell devices with superstrate-type configuration. Monodispersed CIS nanocrystals were synthesized by a colloidal synthetic route and re-dispersed in toluene to form an ink. A spray method was used to coat CIS films onto conducting glass substrates. Prior to CIS film deposition, TiO? and CdS thin films were also prepared as a blocking layer and a buffer layer, respectively. We found that both a TiO? blocking layer and a CdS buffer layer are necessary to generate photoresponses in superstrate-type devices. The best power conversion efficiency (?1.45%) was achieved by the CIS superstrate-type thin film solar cell device with 200 and 100 nm thick TiO? and CdS films, respectively.

Cho JW; Park SJ; Kim W; Min BK

2012-07-01

129

Fabrication of nanocrystal ink based superstrate-type CuInS? thin film solar cells.  

Science.gov (United States)

A CuInS? (CIS) nanocrystal ink was applied to thin film solar cell devices with superstrate-type configuration. Monodispersed CIS nanocrystals were synthesized by a colloidal synthetic route and re-dispersed in toluene to form an ink. A spray method was used to coat CIS films onto conducting glass substrates. Prior to CIS film deposition, TiO? and CdS thin films were also prepared as a blocking layer and a buffer layer, respectively. We found that both a TiO? blocking layer and a CdS buffer layer are necessary to generate photoresponses in superstrate-type devices. The best power conversion efficiency (?1.45%) was achieved by the CIS superstrate-type thin film solar cell device with 200 and 100 nm thick TiO? and CdS films, respectively. PMID:22699212

Cho, Jin Woo; Park, Se Jin; Kim, Woong; Min, Byoung Koun

2012-06-15

130

Texture ZnO Thin-Films and their Application as Front Electrode in Solar Cells  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, three kinds of textured ZnO thin-films (the first kind has the textured structure with both columnar and polygon, the second posses pyramid-like textured structure only, and the third has the textured structure with both crater-like and pyramid-like), were prepared by three kinds of methods, and the application of these ZnO thin-films as a front electrode in solar cell was studied, respectively. In the first method with negative bias voltage and appropriate sputtering parameters, the textured structure with columnar and polygon on the surface of ZnO thin-film are both existence for the sample prepared by direct magnetron sputtering. Using as a front electrode in solar cell, the photoelectric conversion efficiency Eff of 7.00% was obtained. The second method is that by sputtering on the ZnO:Al self-supporting substrate, and the distribution of pyramid-like was gained. Moreover, the higher (8.25%) photoelectric conversion efficiency of solar cell was got. The last method is that by acid-etching the as-deposited ZnO thin-film which possesses mainly both columnar and polygon structure, and the textured ZnO thin-film with both crater-like and pyramid-like structure was obtained, and the photoelectric conversion efficiency of solar cell is 7.10% when using it as front electrode. These results show that the textured ZnO thin-film prepared on self-supporting substrate is more suitable for using as a front electrode in amorphous silicon cells.

Yue-Hui Hu; Yi-Chuan Chen; Hai-Jun Xu; Hao Gao; Wei-Hui Jiang; Fei Hu; Yan-Xiang Wang

2010-01-01

131

Enhanced optical absorption in nanohole-textured silicon thin-film solar cells with rear-located metal particles.  

UK PubMed Central (United Kingdom)

We report the computational modeling of Ag nanoparticles deposited on the rear of a nanohole-textured silicon thin film to achieve higher absorption for silicon solar cells. The silicon nanoholes and the rear-located Ag nanoparticles can enhance the absorption in the silicon thin film. The short circuit current density for nanohole-textured silicon thin film can be further improved by about 11.6% by Ag nanoparticles. The combination of silicon nanoholes and plasmonic metal nanoparticles provides a promising way to enhance the absorption of silicon thin-film solar cells.

Chen Y; Han W; Yang F

2013-10-01

132

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.

2005-06-01

133

Plasmonic effects in amorphous silicon thin film solar cells with metal back contacts.  

UK PubMed Central (United Kingdom)

Plasmonic effects in amorphous silicon thin film solar cells with randomly textured metal back contact were investigated experimentally and numerically. The influence of different metal back contacts with and without ZnO interlayer was studied and losses in the individual layers of the solar cell were quantified. The amorphous silicon thin film solar cells were prepared on randomly textured substrates using large area production equipment and exhibit conversion efficiencies approaching 10%. The optical wave propagation within the solar cells was studied by Finite Difference Time Domain simulations. The quantum efficiency of solar cells with and without ZnO interlayer was simulated and the interplay between the reflection, quantum efficiency and absorption in the back contact will be discussed.

Palanchoke U; Jovanov V; Kurz H; Obermeyer P; Stiebig H; Knipp D

2012-03-01

134

?????????????????? Research Progress of Surface Plasmon Applied in Thin Film Solar Cells  

Directory of Open Access Journals (Sweden)

Full Text Available ????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????In order to transfer light to electricity efficiently, thin film solar cells with the structure of supporting surface plasmons in metal particles are designed. Due to the surface plasmons can guide and localize lights, the physical thickness of solar photovoltaic absorbing layer can be decreased as well as the absorption in photovoltaic devices can be improved. This technology plays an important role in fabricating low-cost and high-efficiency thin film solar cells. In this review, the latest progress of the application of plasmonics in solar cells is researched, the mechanism of the intersection of plasmonics and photovoltaics is expounded, and an outlook on the future of solar cells based on these principles is offered.

???; ???; ???; ???; ???; ??; ???

2011-01-01

135

Transit time studies of junction location in thin-film solar cells  

Energy Technology Data Exchange (ETDEWEB)

The active junction in Cd(Zn)S/CuInSe/sub 2/ thin-film solar cells was investigated by a pulse photoconductivity technique. We observed the diffusion transit time of minority carriers to a homojunction internal to the CuInSe/sub 2/. No electrical activity at the heterojunction was indicated.

Ahrenkiel, R.K.; Matson, R.J.

1985-05-01

136

Design of plasmonic thin-film solar cells with broadband absorption enhancements  

Energy Technology Data Exchange (ETDEWEB)

Noble metal nanostructures can enhance absorption in thin-film solar cells by simultaneously taking advantage of i) high near-fields surrounding the nanostructures close to their surface plasmon resonance frequency and ii) coupling to waveguide modes. We develop basic design rules for the realization of broadband absorption enhancements for such structures. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

Pala, Ragip A.; White, Justin; Barnard, Edward; Liu, John; Brongersma, Mark L. [Geballe Laboratory for Advanced Materials Stanford University Stanford, CA 94305 (United States)

2009-09-11

137

Earth abundant materials for high efficiency heterojunction thin film solar cells  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We investigate earth abundant materials for thin-film solar cells that can meet tens of terawatts level deployment potential. Candidate materials are identified by combinatorial search, large-scale electronic structure calculations, and literature reviews. We identified cuprous oxide (Cu2O) as a pro...

Buonassisi, Tonio; Bertoni, Mariana I.; Chan, Maria K.; Ceder, Gerbrand; Lee, Yun Seog

138

Modulated photonic-crystal structures as broadband back reflectors in thin-film solar cells  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A concept of a modulated one-dimensional photonic-crystal (PC) structure is introduced as a back reflector for thin-film solar cells. The structure comprises two PC parts, each consisting of layers of different thicknesses. Using layers of amorphous silicon and amorphous silicon nitride a reflectanc...

Krc, J.; Zeman, M.; Luxembourg, S.L.; Topic, M.

139

Optimization of amorphous silicon thin film solar cells for flexible photovoltaics  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We investigate amorphous silicon (a-Si:H) thin film solar cells in the n-i-p or substrate configuration that allows the use of nontransparent and flexible substrates such as metal or plastic foils such as polyethylene- naphtalate (PEN). A substrate texture is used to scatter the ligh...

Sderstrm, T.; Haug, F.-J.; Terrazzoni-Daudrix, V.; Ballif, C.

140

Understanding of photocurrent enhancement in real thin film solar cells: towards optimal onedimensional gratings  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Despite the progress in the engineering of structures to enhance photocurrent in thin film solar cells, there are few comprehensive studies which provide general and intuitive insight into the problem of light trapping. Also, lack of theoretical propositions which are consistent with fabrication is ...

Naqavi, Ali; Sderstrm, Karin; Paeder, Vincent; Scharf, Toralf; Herzig, Hans Peter; Ballif, Christophe

 
 
 
 
141

Diffraction and absorption enhancement from textured back reflectors of thin film solar cells  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We study light scattering and absorption in thin film solar cells, using a model system of a sinusoidally textured silver reflector and dielectric layers of ZnO and amorphous silicon. Experimental results are compared to a theoretical model based on a Rayleigh expansion. Taking into account the expl...

Haug, F.-J.; Naqavi, A.; Ballif, C.

142

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 f...

R. B. Bergmann; T. J. Rinke; R. M. Hausner; M. Grauvogl; M. Vetter; J. H. Werner

143

Modelling and Degradation Characteristics of Thin-film CIGS Solar Cells  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Thin-film solar cells based around the absorber material CuIn1-xGaxSe2 (CIGS) are studied with respect to their stability characteristics, and different ways of modelling device operation are investigated. Two ways of modelling spatial inhomogeneities are detailed...

Malm, Ulf

144

Progress in Polycrystalline Thin-Film Cu(In,Ga)Se2 Solar Cells  

Directory of Open Access Journals (Sweden)

Full Text Available For some time, the chalcopyrite semiconductor CuInSe2 and its alloy with Ga and/or S [Cu(InGa)Se2 or Cu(InGa)(Se,S)2], 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.

Udai P. Singh; Surya P. Patra

2010-01-01

145

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 a...

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

146

Research and Developmental Study on MIS Thin Film Solar Cells of Amorphus Hydrogenated Silicon. Pt. 2.  

Science.gov (United States)

The objective of these investigations was to study the suitability of sputtered hydrogenated amorphous silicon (a-Si:H) layers for thin film solar cells and to improve them for this application. The most important task was to optimise the undoped intrinsi...

H. Jaeger D. Engemann M. Ilgenstein W. Roessler

1984-01-01

147

Mixed phase silicon oxide layers for thin-film silicon solar cells  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Lower absorption, lower refractive index and tunable resistance are three advantages of doped silicon oxide containing nanocrystalline silicon grains (nc-SiOx) compared to doped microcrystalline silicon, for the use as p- and n-type layers in thin-film silicon solar cells. In this study we show how ...

Cuony, Peter; T. L. Alexander, Duncan; Lfgren, Nils Linus; Krumrey, Michael; Marending, Michael; Despeisse, Matthieu

148

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2012-06-11

149

Technical use of solar energy. Part 1. Thin films solar cells. Final report, February 1982  

Energy Technology Data Exchange (ETDEWEB)

Due to the potentialities of Cu2-xS-CdS thin film solar cells, several companies installed production lines for this type of solar cell. Besides investigations for further enhancing efficiency and long-term stability, for gaining data of physical and electronical parameters, and for improving the theoretical knowledge of the cell, materials and technologies are investigated which look promising for large-scale industrial production. Solar cells with an area of 42 sq cm are realized, showing efficiencies of up to 8% outdoor tests reveal that no system-inherent degradation mechanism exists when properly encapsulated cells are tested under realistic operation conditions. Large-area thin films of amorphous silicon with definite and reproducible properties are produced with two methods, both of which are well suited for the preparation: RF-sputtering in Ar/H2-mixtures and glow discharge in SiH4. Correlations exist between results of plasma diagnostics and analyses of the layers, allowing definite variations and an optimization of the production parameters. Various methods for the injection of different types of dopants into the plasma result in the implantation of electronically active dopants into the layers.

Arndt, W.; Bauer, G.H.; Berger, H.U.; Bloss, W.H.; Hewig, G.H.; Pfisterer, F.; Schock, H.W.

1983-12-01

150

Thin film solar cells. (Latest citations from the NTIS bibliographic database). Published Search  

Energy Technology Data Exchange (ETDEWEB)

The bibliography contains citations concerning research and development of high-efficiency and low-cost thin film solar cells. References discuss the design and fabrication of silicon, gallium arsenide, copper selenide, indium selenide, cadmium telluride, and copper indium selenide solar cells. Applications in space and utilities are examined. Government projects and foreign technology are also reviewed. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

NONE

1997-11-01

151

Microstructural properties of CVD-grown CuGaSe2 based thin film solar cells  

International Nuclear Information System (INIS)

Microstructural aspects of interfaces involved in CuGaSe2 (CGSe) based thin film solar cells have been investigated. High resolution transmission electron microscopy and scanning energy dispersive X-ray techniques have been employed for the analysis of complete solar cell cross-sections, revealing details at nanometer scale of the soda lime glass/Mo/MoSe2/CGSe/CdS/i:ZnO/Ga:ZnO heterostructure making up the complete devices.

2003-05-01

152

Single-layer organic-inorganic-hybrid thin-film encapsulation for organic solar cells  

Science.gov (United States)

We demonstrate an organic-inorganic-hybrid thin-film encapsulation technique for organic solar cells. The single-layer encapsulation thin film is deposited from a gas mixture of hexamethyldisiloxane and oxygen by plasma-enhanced chemical vapour deposition at room temperature. The encapsulation film contains organic and inorganic compounds: the inorganic compounds serve as the permeation barriers, and the organic compounds reduce defect propagation. An optical transmission of ?90% in the visible light region and a water vapour transmission rate of 3.6 10-6 g m-2 day are obtained for a 1.5 m thick hybrid film. Efficiency decay is not observed in the inverted organic solar cell coated with this thin film after exposure to air for 3600 h in contrast, the efficiency of the unencapsulated counterpart degrades rapidly and fails after exposure to air for 120 h. The obtained results show that this organic-inorganic-hybrid thin film is promising for the encapsulation of organic solar cells.

Li, Yun-Shiuan; Tsai, Chih-Hung; Kao, Shao-Hsuan; Wu, I.-Wen; Chen, Jian-Zhang; Wu, Chih-I.; Lin, Ching-Fuh; Cheng, I.-Chun

2013-10-01

153

Improvements in CdS Thin Film Solar Cells.  

Science.gov (United States)

The report is concerned with two areas in the cadmium sulfide solar cell development program: (1) a program of flight panel construction for satellite and balloon testing of CdS solar cells and (2) a developmental effort for improving the stability and ef...

W. F. Dunn H. E. Nastelin

1970-01-01

154

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

1992-04-01

155

Microcrystalline silicon for large area thin film solar cells  

International Nuclear Information System (INIS)

We present a comprehensive study of microcrystalline silicon (?c-Si:H) solar cells prepared by plasma-enhanced chemical vapour deposition (PECVD) at 13.56 MHz excitation frequency. In the first step the cell development was performed in a small area PECVD reactor showing the relationship between the deposition process parameters and the resulting solar cell performance. Focus was on the influence of deposition pressure, electrode distance and the application of a pulsed plasma on high rate deposition of solar cells. Subsequent up-scaling to a substrate area of 30x30 cm2 confirmed the suitability of the process for large area reactors. The influence of i-layer deposition parameters on solar cell performance was studied directly in p-i-n cells prepared on textured ZnO. Solar cell efficiencies up to 9% were achieved at deposition rates of 5-6 A/s for the i-layer using high plasma powers. Applied as bottom cell in a-Si:H/?c-Si:H tandem cells a stable cell efficiency of 11.2% could be obtained. The excellent homogeneity was proven by the realization of first modules with an aperture area of 689 cm2 and an active area initial efficiency of 10.3% (stable: 8.9%) using an established base technology for laser patterning and back contact sputtering at RWE Solar GmbH.

2003-03-03

156

High-efficiency thin-film solar cells for the conversion of concentrated radiation  

Energy Technology Data Exchange (ETDEWEB)

The objective of the study was to investigate the possibility of increasing the efficiency of thin-film solar cells with coplanar back contacts for the conversion of concentrated solar radiation. It is shown that, in the thin-film solar cells described here, the cell shading factor can be reduced to a minimum since it does not depend on the p-contact area but is determined solely by the area of etched grooves in a thin (7 microns) layer of GaAs. The cells used in the study have a shading factor of 2.5 percent, and a further reduction by an order of magnitude is shown to be possible. 6 references.

Andreev, V.M.; Burba, T.S.; Dorgan, V.V.; Trofim, V.G.; Chumak, V.A.

1987-09-01

157

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

Energy Technology Data Exchange (ETDEWEB)

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.

Fahr, Stephan

2011-11-22

158

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 trans...

Owen, Jorj Ian

159

Microstructure Analysis and Properties of Anti-Reflection Thin Films for Spherical Silicon Solar Cells  

Directory of Open Access Journals (Sweden)

Full Text Available Structure and properties of anti-reflection thin films of spherical silicon solar cells were investigated and discussed. Conversion efficiencies of spherical Si solar cells coated with F-doped SnO2 anti-reflection films were improved by annealing. Optical absorption and fluorescence of the solar cells increased after annealing. Lattice constants of F-doped SnO2 anti-reflection layers, which were investigated by X-ray diffraction, decreased after annealing. A mechanism of atomic diffusion of F in SnO2 was discussed. The present work indicated a guideline for spherical silicon solar cells with higher efficiencies.

Masato Kanayama; Takeo Oku; Tsuyoshi Akiyama; Youichi Kanamori; Satoshi Seo; Jun Takami; Yoshimasa Ohnishi; Yoshikazu Ohtani; Mikio Murozono

2013-01-01

160

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

Science.gov (United States)

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

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

2012-09-01

 
 
 
 
161

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

UK PubMed Central (United Kingdom)

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.

Zhao Y; Chen F; Shen Q; Zhang L

2012-09-01

162

Thin film multi-junction solar cell for water photoelectrolysis  

Energy Technology Data Exchange (ETDEWEB)

Triple-junction (p-i-n)[sup 3] photovoltaic devices, based on hydrogenerated amorphous silicon thin films, have been prepared, exhibiting open-circuit voltages larger than 2V, short-circuit currents of about 5mA cm[sup -2] and overall photovoltaic efficiencies higher than 6%. Such units can sustain water electrolysis in sulphuric acid solution and therefore can be used as photoelectrodes in integrated photovoltaic-electrochemical systems. (author)

Gramaccioni, C.; Selvaggi, A.; Galluzzi, F. (Eniricerche SpA, Monterotondo (Italy))

1993-01-01

163

Amorphous silicon/polycrystalline thin film solar cells.  

Science.gov (United States)

An improved photovoltaic solar cell is described including a p-type amorphous silicon layer, intrinsic amorphous silicon, and an n-type polycrystalline semiconductor such as cadmium sulfide, cadmium zinc sulfide, zinc selenide, gallium phosphide, and gall...

H. S. Ullal

1991-01-01

164

Polymorphous silicon thin films produced in dusty plasmas: application to solar cells  

International Nuclear Information System (INIS)

We summarize our current understanding of the optimization of PIN solar cells produced by plasma enhanced chemical vapour deposition from silane-hydrogen mixtures. To increase the deposition rate, the discharge is operated under plasma conditions close to powder formation, where silicon nanocrystals contribute to the deposition of so-called polymorphous silicon thin films. We show that the increase in deposition rate can be achieved via an accurate control of the plasma parameters. However, this also results in a highly defective interface in the solar cells due to the bombardment of the P-layer by positively charged nanocrystals during the deposition of the I-layer. We show that decreasing the ion energy by increasing the total pressure or by using silane-helium mixtures allows us to increase both the deposition rate and the solar cells efficiency, as required for cost effective thin film photovoltaics.

2004-12-01

165

Thin-Film Solar Cell Fabricated on a Flexible Metallic Substrate  

Science.gov (United States)

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).

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

2006-05-30

166

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

Energy Technology Data Exchange (ETDEWEB)

This project addresses the problem of lower solar conversion efficiency and waste in the typical solar cell manufacturing process. The work from the proposed development will lead toward developing a system which should be able to increase solar panel conversion efficiency by an additional 12-15% resulting in lower cost panels, increased solar technology adoption, reduced carbon emissions and reduced dependency on foreign oil. All solar cell manufacturing processes today suffer from manufacturing inefficiencies that currently lead to lower product quality and lower conversion efficiency, increased product cost and greater material and energy consumption. This results in slower solar energy adoption and extends the time solar cells will reach grid parity with traditional energy sources. The thin film solar panel manufacturers struggle on a daily basis with the problem of thin film thickness non-uniformity and other parameters variances over the deposited substrates, which significantly degrade their manufacturing yield and quality. Optical monitoring of the thin films during the process of the film deposition is widely perceived as a necessary step towards resolving the non-uniformity and non-homogeneity problem. In order to enable the development of an optical control system for solar cell manufacturing, a new type of low cost optical sensor is needed, able to acquire local information about the panel under deposition and measure its local characteristics, including the light scattering in very close proximity to the surface of the film. This information cannot be obtained by monitoring from outside the deposition chamber (as traditional monitoring systems do) due to the significant signal attenuation and loss of its scattering component before the reflected beam reaches the detector. In addition, it would be too costly to install traditional external in-situ monitoring systems to perform any real-time monitoring over large solar panels, since it would require significant equipment refurbishing needed for installation of multiple separate ellipsometric systems, and development of customized software to control all of them simultaneously. The proposed optical monitoring system comprises AccuStratas fiber optics sensors installed inside the thin film deposition equipment, a hardware module of different components (beyond the scope of this project) and our software program with iterative predicting capability able to control material bandgap and surface roughness as films are deposited. Our miniature fiber optics monitoring sensors are installed inside the vacuum chamber compartments in very close proximity where the independent layers are deposited (an option patented by us in 2003). The optical monitoring system measures two of the most important parameters of the photovoltaic thin films during deposition on a moving solar panel - material bandgap and surface roughness. In this program each sensor array consists of two fiber optics sensors monitoring two independent areas of the panel under deposition. Based on the monitored parameters and their change in time and from position to position on the panel, the system is able to provide to the equipment operator immediate information about the thin films as they are deposited. This DoE Supply Chain program is considered the first step towards the development of intelligent optical control system capable of dynamically adjusting the manufacturing process on-the-fly in order to achieve better performance. The proposed system will improve the thin film solar cell manufacturing by improving the quality of the individual solar cells and will allow for the manufacturing of more consistent and uniform products resulting in higher solar conversion efficiency and manufacturing yield. It will have a significant impact on the multibillion-dollar thin film solar market. We estimate that the financial impact of these improvements if adopted by only 10% of the industry ($7.7 Billion) would result in about $1.5 Billion in savings by 2015 (at the assumed 20% improvement). This can b

George Atanasoff

2010-10-29

167

Laser process for extended silicon thin film solar cells  

International Nuclear Information System (INIS)

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.

2011-10-31

168

Amorphous silicon/polycrystalline thin film solar cells  

Energy Technology Data Exchange (ETDEWEB)

An improved photovoltaic solar cell is described including a p-type amorphous silicon layer, intrinsic amorphous silicon, and an n-type polycrystalline semiconductor such as cadmium sulfide, cadmium zinc sulfide, zinc selenide, gallium phosphide, and gallium nitride. The polycrystalline semiconductor has an energy bandgap greater than that of the amorphous silicon. The solar cell can be provided as a single-junction device or a multijunction device.

Ullal, H.S.

1991-03-13

169

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 suf...

Schmidt, Sebastian Simon

170

Optical Layers for Thin-film Silicon Solar Cells  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this work we develop and analyze optical layers for use in Micromorph solar cells, a tandem configuration with an amorphous silicon top cell and a microcrystalline silicon bottom cell. The morphology of the front electrode has a decisive role in maximizing the efficiency o...

Cuony, Peter

171

Multilayer silver nanoparticles for light trapping in thin film solar cells  

Science.gov (United States)

In this paper, a systematic design and analysis of thin film crystalline silicon solar cells incorporated with a new style of multilayer silver (Ag) nanoparticles (NPs) array is presented. Using numerical simulations, we showed that multilayer Ag NPs provide better light trapping than single layer Ag NPs when the Ag NPs are located on the rear of the solar cell. Furthermore, Ag NP double layers on the rear achieved the best light absorption enhancement for solar cells. Ag NP double layers showed a 6.65% increase in intergraded quantum efficiency across the solar spectrum compared with single layer structures. The parasitic absorption occurring in Ag NP bottom layers was also discussed.

Shi, Yanpeng; Wang, Xiaodong; Liu, Wen; Yang, Tianshu; Xu, Rui; Yang, Fuhua

2013-05-01

172

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

1997-11-01

173

Selectiveness of laser processing due to energy coupling localization: case of thin film solar cell scribing  

Science.gov (United States)

Selectiveness of the laser processing is the top-most important for applications of the processing technology in thin-film electronics, including photovoltaics. Coupling of laser energy in multilayered thin-film structures, depending on photo-physical properties of the layers and laser wavelength was investigated experimentally and theoretically. Energy coupling within thin films highly depends on the film structure. The finite element and two-temperature models were applied to simulate the energy and temperature distributions inside the stack of different layers of a thin-film solar cell during a picosecond laser irradiation. Reaction of the films to the laser irradiation was conditioned by optical properties of the layers at the wavelength of laser radiation. Simulation results are consistent with the experimental data achieved in laser scribing of copper-indium-gallium diselenide (CIGS) solar cells on a flexible polymer substrate using picosecond-pulsed lasers. Selection of the right laser wavelength (1064 nm or 1572 nm) enabled keeping the energy coupling in a well-defined volume at the interlayer interface. High absorption at inner interface of the layers triggered localized temperature increase. Transient stress caused by the rapid temperature rise facilitating peeling of the films rather than evaporation. Ultra-short pulses ensured high energy input rate into absorbing material permitting peeling of the layers with no influence on the remaining material.

Ra?iukaitis, G.; Grubinskas, S.; Ge?ys, P.; Gedvilas, M.

2013-07-01

174

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

CERN Document Server

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...

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

2013-01-01

175

Quantum efficiency of thin film silicon solar cells on a highly doped substrate  

Energy Technology Data Exchange (ETDEWEB)

The analysis of internal quantum efficiency of monocrystalline silicon solar cells is extended to thin film cells on a highly doped substrate. The model evaluates the internal quantum efficiency of cells in the limit of strong and weak absorption, i.e. for light with absorption lengths falling below and exceeding the base width of the cells. These two times yield two characteristic lengths, which allow one to distinguish between recombination within the epitaxial layer and into the substrate. The implicit equations for the diffusion lengths of base and substrate are numerically and graphically solved. In all cases, the evaluation gives limiting values. For the special case of thin film silicon solar cells, the authors are able to determine the substrate diffusion length with high accuracy. For the base diffusion length they deduce a lower bound.

Hirsch, M.; Brendel, R.; Werner, J.H. [Max-Planck-Inst. fuer Festkoerperforschung, Stuttgart (Germany); Rau, U. [Univ. Bayreuth (Germany). Physikalisches Inst.

1994-12-31

176

CIGS thin-film solar cells on steel substrates  

International Nuclear Information System (INIS)

Steel foil is an attractive candidate for use as a flexible substrate material for Cu(Inx,Ga1-x)Se2 solar cells (CIGS). It is stable at the high temperatures involved during CIGS processing and is also commercially available. Stainless chromium (Cr) steel is more expensive than Cr-free steel sheets, but the latter are not stable against corrosion. We processed CIGS solar cells on both types of substrates. The main problem arising here is the diffusion of detrimental elements from the substrate into the CIGS absorber layer. The diffusion of iron (Fe) and other substrate elements into the CIGS layer was investigated by Secondary Ion Mass Spectrometry (SIMS). The influence of the impurities on the solar cell parameters was determined by current voltage (JV) and external quantum efficiency (EQE) measurements. A direct correlation between the Fe content in the CIGS layer and the solar cell efficiency was found. The diffusion of Fe could be strongly reduced by a diffusion barrier layer. Thus we could process CIGS solar cells with a conversion efficiency of 12.8% even on Cr-free steel substrate

2009-02-02

177

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

Energy Technology Data Exchange (ETDEWEB)

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.

Simburger, Edward J. [Aerospace Corporation, El Segundo, CA 90245 (United States)]. E-mail: edward.j.simburger@aero.org; Matsumoto, James H. [Aerospace Corporation, El Segundo, CA 90245 (United States); Giants, Thomas W. [Aerospace Corporation, El Segundo, CA 90245 (United States); Garcia, Alexander [The Aerospace Corporation, El Segundo, CA 90245 (United States); Liu, Simon [Aerospace Corporation, El Segundo, CA 90245 (United States); Rawal, Suraj P. [Lockheed Martin Corporation, Denver, CO 80125 (United States); Perry, Alan R. [Lockheed Martin Corporation, Denver, CO 80125 (United States); Marshall, Craig H. [Lockheed Martin Corporation, Denver, CO 80125 (United States); Lin, John K. [ILC Dover Incorporated, Dover, DE 19946 (United States); Scarborough, Stephen E. [ILC Dover Incorporated, Dover, DE 19946 (United States); Curtis, Henry B. [NASA Glen Research Center, Cleveland, OH 44135 (United States); Kerslake, Thomas W. [NASA Glen Research Center, Cleveland, OH 44135 (United States); Peterson, Todd T. [NASA Glen Research Center, Cleveland, OH 44135 (United States)

2005-02-15

178

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

2005-02-15

179

Advanced characterization techniques for thin film solar cells  

CERN Document Server

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

Rau, Uwe; Kirchartz, Thomas

2011-01-01

180

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

UK PubMed Central (United Kingdom)

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.

Dai P; Zhang G; Chen Y; Jiang H; Feng Z; Lin Z; Zhan J

2012-03-01

 
 
 
 
181

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

Science.gov (United States)

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

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

2012-02-09

182

Polycrystalline Silicon Thin-Film Solar Cells on AIT-Textured Glass Superstrates  

Directory of Open Access Journals (Sweden)

Full Text Available A new glass texturing method (AIT—aluminium-induced texturisation) has recently been developed by our group. In the present work, the potential of this method is explored by fabricating PLASMA poly-Si thin-film solar cells on glass superstrates that were textured with the AIT method. Using an interdigitated metallisation scheme with a full-area Al rear contact, PLASMA cells with an efficiency of up to 7% are realised. This promising result shows that the AIT glass texturing method is fully compatible with the fabrication of poly-Si thin-film solar cells on glass using solid phase crystallisation (SPC) of PECVD-deposited amorphous silicon precursor diodes. As such, there are now two distinctly different glass texturing methods—the AIT method and CSG Solar's glass bead method—that are known to be capable of producing efficient SPC poly-Si thin-film solar cells on glass.

Per I. Widenborg; Armin G. Aberle

2007-01-01

183

Schottky solar cells based on CsSnI3 thin-films  

Science.gov (United States)

We describe a Schottky solar cell based on the perovskite semiconductor CsSnI3 thin-film. The cell consists of a simple layer structure of indium-tin-oxide/CsSnI3/Au/Ti on glass substrate. The measured power conversion efficiency is 0.9%, which is limited by the series and shunt resistance. The influence of light intensity on open-circuit voltage and short-circuit current supports the Schottky solar cell model. Additionally, the spectrally resolved short-circuit current was measured, confirming the unintentionally doped CsSnI3 is of p-type characteristics. The CsSnI3 thin-film was synthesized by alternately depositing layers of SnCl2 and CsI on glass substrate followed by a thermal annealing process.

Chen, Zhuo; Wang, Jian J.; Ren, Yuhang; Yu, Chonglong; Shum, Kai

2012-08-01

184

Thin film solar cells using impure polycrystalline silicon  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Epitaxial solar cells have been studied with the view of using rather impure upgraded metallurgical grade (UMG)-Si as a substrate material. It is confirmed that transition elements have segregated during ingot growth and that impurities such as B, P, Al do not diffuse from substrate to epilayers, so...

Rodot, M.; Barbe, M.; Bouree, J.E.; Perraki, V.; Revel, G.; Kishore, R.; Pastol, J.L.; Mertens, R.; Caymax, M.; Eyckmans, M.

185

Quantum efficiency enhancement in selectively transparent silicon thin film solar cells by distributed Bragg reflectors.  

Science.gov (United States)

This work demonstrated a-Si:H thin-film solar cells with backside TiO(2) / SiO(2) distributed Bragg reflectors (DBRs) for applications involving building-integrated photovoltaics (BIPVs). Selectively transparent solar cells are formed by adjusting the positions of the DBR stop bands to allow the transmission of certain parts of light through the solar cells. Measurement and simulation results indicate that the transmission of blue light (430 ~500 nm) with the combination of three DBR mirrors has the highest increase in conversion efficiency. PMID:23326830

Kuo, M Y; Hsing, J Y; Chiu, T T; Li, C N; Kuo, W T; Lay, T S; Shih, M H

2012-11-01

186

Quantum efficiency enhancement in selectively transparent silicon thin film solar cells by distributed Bragg reflectors.  

UK PubMed Central (United Kingdom)

This work demonstrated a-Si:H thin-film solar cells with backside TiO(2)/ SiO(2) distributed Bragg reflectors (DBRs) for applications involving building-integrated photovoltaics (BIPVs). Selectively transparent solar cells are formed by adjusting the positions of the DBR stop bands to allow the transmission of certain parts of light through the solar cells. Measurement and simulation results indicate that the transmission of blue light (430 ~500 nm) with the combination of three DBR mirrors has the highest increase in conversion efficiency.

Kuo MY; Hsing JY; Chiu TT; Li CN; Kuo WT; Lay TS; Shih MH

2012-11-01

187

Approaching the Lambertian limit in randomly textured thin-film solar cells.  

UK PubMed Central (United Kingdom)

The Lambertian limit for solar cells is a benchmark for evaluating their efficiency. It has been shown that the performance of either extremely thick or extremely thin solar cells can be driven close to this limit by using an appropriate photon management. Here we show that this is likewise possible for realistic, practically relevant thin-film solar cells based on amorphous silicon. Most importantly, we achieve this goal by relying on random textures already incorporated into state-of-the-art superstrates; with the only subtlety that their topology has to be downscaled to typical feature sizes of about 100 nm.

Fahr S; Kirchartz T; Rockstuhl C; Lederer F

2011-07-01

188

Thin-film solar cells on perlite glass-ceramic substrates  

Science.gov (United States)

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%.

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

189

Light trapping in thin-film solar cells via scattering by nanostructured antireflection coatings  

Science.gov (United States)

The use of nanostructured TiO2 layers fabricated on thin-film solar cells to provide, simultaneously, both antireflection functionality and light trapping via scattering of long-wavelength photons into guided optical modes is demonstrated and analyzed in thin-film quantum-well solar cells. Nanosphere lithography is used for fabrication of periodic arrays of subwavelength-scale TiO2 structures, and separation of active device layers from their epitaxial growth substrate and integration with the nanostructured TiO2 layer enables increased optical absorption via coupling to both Fabry-Perot resonances and guided lateral propagation modes in the semiconductor. The nanostructured TiO2 layer is shown to act as a graded-index coating at optical wavelengths and simultaneously to scatter incident light into guided optical modes within the device. The dependence of these effects on angle of incidence is also analyzed.

Li, X. H.; Li, P. C.; Hu, D. Z.; Schaadt, D. M.; Yu, E. T.

2013-07-01

190

TCAD studies of novel nanoplate amorphous silicon alloy thin-film solar cells  

International Nuclear Information System (INIS)

A novel nanoplate-structured thin-film solar cell was investigated that could solve the conflict between light absorption and carrier transport in a p-type amorphous silicon carbide (a-SiC)/i-type amorphous silicon germanide (a-SiGe)/n-type amorphous silicon (a-Si) thin-film solar cell. This structure has an n-type a-Si nanoplate array on the substrate, a-SiC p-layer, and an a-SiGe i-layer which are sequentially grown along the surface of each n-type a-Si nanoplate. Under illumination by sunlight, light is absorbed along the vertical direction of the nanoplate, while the carrier transport is along the horizontal direction. The nanoplate structure may absorb most of the sunlight and provide a thinner film for the effective transport of photon-generated carriers as compared to the conventional planar structure.

2011-12-30

191

Thin-film solar cells with patterned surfaces; Duennfilmsolarzellen mit strukturierten Oberflaechen  

Energy Technology Data Exchange (ETDEWEB)

Thin film solar cells have a multilayer structure with an electrically-conductive lower layer, a range of intermediate layers and the active silicon outer layer. The efficiency of such a combination can be significantly increased by appropriate patterning, especially at the interface between the interlayer and the silicon. Key pattern parameters are the lateral dimensions, the height of the pattern protrusions and the pattern shape. Of great importance is the interaction of the pattern used and capture of the incident light, where photons are trapped with maximum efficiency in a three-dimensional topography with lateral features of order 1{mu}m and structure height of 300 to 500nm. In order to optimise the performance of these thin-film silicon solar cells, novel processes are being developed to create the most efficient micro- and nano-patterned surfaces. (orig.)

Stiebig, H.; Haase, C.; Schulte, M.; Huepkes, J.; Beyer, W. [Forschungszentrum Juelich GmbH (DE). Inst. fuer Energieforschung - Photovoltaik (IEF-5)

2009-07-01

192

Effects of Deposition Rate on the Properties of CuPc Thin Films and Solar Cells  

Science.gov (United States)

We investigated the effects of deposition rate on the properties of copper phthalocyanine (CuPc) thin films and the performance of CuPc/C60 heterojunction organic solar cells prepared by vacuum thermal evaporation method. We found that the organic solar cell with higher CuPc deposition rate (RCuPc) of around 4.0 /s showed a larger short circuit current density of around 5.79 mA/cm2 and a higher power conversion efficiency of around 1.3%, which were about 1.8- and 2-times compared to those of the devices with RCuPc of 0.1 /s, respectively. We also found that the CuPc single layer devices with higher RCuPc exhibited a larger current density, which may be due to a higher mobility and lower trap density in CuPc thin films with higher RCuPc.

Li, Shuang; Chen, Jianhong; Zhou, Xiang

2013-05-01

193

2D device modelling and finite element simulations for thin-film solar cells  

Energy Technology Data Exchange (ETDEWEB)

Thin-film heterojunction solar cell devices are modelled in two dimensions, from fundamental material parameters, using the finite element method. The electrostatic potential is solved for, together with the quasi-Fermi levels, while optical absorption is calculated from n and k values of the materials used. In this implementation, all material parameters can be input as functions of spatial coordinates, which makes it very flexible when applied to materials with inhomogeneities. As an example of the model in use, it is applied to a thin-film solar cell based on a structure with a CIGS absorber layer, a CdS buffer layer and a ZnO/ZAO transparent front contact. The effects of spatial inhomogeneities in the band gap energy and in the mid-gap trap level density on device performance are simulated. (author)

Malm, Ulf; Edoff, Marika [Aangstroem Solar Center, Uppsala University, P.O. Box 534, SE-751 21 Uppsala (Sweden)

2009-06-15

194

Enhanced efficiency of light-trapping nanoantenna arrays for thin-film solar cells.  

UK PubMed Central (United Kingdom)

We suggest a new type of efficient light-trapping structures for thin-film solar cells based on arrays of planar nanoantennas operating far from their plasmon resonances. The operation principle of our structures relies on the excitation of collective modes of the nanoantenna arrays whose electric field is localized between the adjacent metal elements. We calculate a substantial enhancement of the short-circuit photocurrent for photovoltaic layers as thin as 100-150 nm. We compare our light-trapping structures with conventional anti-reflecting coatings and demonstrate that our design approach is more efficient. We show that it may provide a general background for different types of broadband light-trapping structures compatible with large-area fabrication technologies for thin-film solar cells.

Simovski C; Morits D; Voroshilov P; Guzhva M; Belov P; Kivshar Y

2013-07-01

195

Present Status and Future Prospects of Silicon Thin-Film Solar Cells  

Science.gov (United States)

In this report, an overview of the recent status of photovoltaic (PV) power generation is first presented from the viewpoint of reducing CO2 emission. Next, the Japanese roadmap for the research and development (R&D) of PV power generation and the progress in the development of various solar cells are explained. In addition, the present status and future prospects of amorphous silicon (a-Si) thin-film solar cells, which are expected to enter the stage of full-scale practical application in the near future, are described. For a-Si single-junction solar cells, the conversion efficiency of their large-area modules has now reached 6--8%, and their practical application to megawatt solar systems has started. Meanwhile, the focus of R&D has been shifting to a-Si and microcrystalline silicon (?c-Si) tandem solar cells. Thus far, a-Si/?c-Si tandem solar cell modules with conversion efficiency exceeding 13% have been reported. In addition, triple-junction solar cells, whose target year for practical application is 2025 or later, are introduced, as well as innovative thin-film full-spectrum solar cells, whose target year of realization is 2050.

Konagai, Makoto

2011-03-01

196

High-efficiency, Cooper ternary, thin-film solar cells  

Science.gov (United States)

A new, two-stage process for depositing CuInSe2 films has been developed. In this method, copper and indium metal layers were sequentially electroplated onto a molybdenum-coated glass substrate with a fixed Cu/In ratio. This metal stack was selenized at 400C under an atmosphere of H2Se gas. Single-phase InSe2 films thus obtained were used to fabricate CuInSe2/CdS solar cells. Evaporated CdS films were used for device fabrication. Solar cells 1.0 sq cm in area had a conversion efficiency in the range of 7.0% to 7.3% without an antireflection coating. Correcting for the reflective losses and the grid shading, the active area efficiency for these cells was projected to be around 10.0%.

Kapur, V. K.; Basol, B. M.; Tseng, E. S.

1987-02-01

197

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

International Nuclear Information System (INIS)

[en]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

2012-10-15

198

The analysis of CdS thin film at the processes of manufacturing CdS/CdTe solar cells  

Science.gov (United States)

In sequence, the deposited CdS thin film had undergone physical and optical changes by the processes of manufacturing CdS/CdTe solar cells. CdS thin film was manufactured by the Chemical Bath Deposition (CBD) method. The aqueous solution was based on ammonia solution. The temperature of bath system was 75 C and deposition time was 50 min. The thickness of deposited CdS thin film was about 200 nm. The substrate was the glass coated with SnO2:F thin film.The following process was the deposition of CdTe thin film by the Closed-Space-Sublimation (CSS) method. The final process was the CdCl2 heat treatment at N2+O2 atmosphere, and the contrast experiment progressed for CdCl2-CdS thin film after CSS process at N2 atmosphere.The phase transition of CdS thin film, stress relaxation and optical band gap narrowing were developed by each process. And so, the formation of cadmium oxide was detected after the CdCl2 heat treatment. It influenced to increase the optical band gap of CdS thin film.The variation in the structure properties, optical properties and residual stresses of CdS thin film was analyzed by X-ray diffractometer (XRD), Raman spectroscopy and ultraviolet (UV)-visible (VIS) spectroscopy.

Chun, S.; Jung, Y.; Kim, J.; Kim, D.

2011-07-01

199

Photovoltaic mechanisms in polycrystalline thin-film silicon solar cells  

Energy Technology Data Exchange (ETDEWEB)

Fundamental limitations on the performance of Si solar cells are shown to be quite different from those that have been conventionally invoked. Particularly for heavy-doping effects, the usual models are shown to be invalid and a new method is devised for calculating the reverse saturation current of a heavily doped device in which nearly all minority carriers reach the junction (viz., good blue-response). Calculations by the new method show: (1) increased doping above 10/sup 18/cm/sup -3/ does not improve the open-circuit voltage as has been thought, and (2) previous estimates of bandgap varrowing in diffused cells are much too high because of the neglect of Auger recombination effects. Also of importance are the effects of doping gradients and their relation to the properties of the front surface of a diffused-junction cell; experiments are clarifying some of these relations. These experiments have led to a new, simple method of separating the internal optoelectronic properties of a solar cell (or optical detector) from the reflectance properties of the front surface. This method thus provides a direct means of evaluating the effectiveness of antireflection coatings on such devices.

Redfield, D.

1980-02-01

200

Thin film photovoltaic cell  

Energy Technology Data Exchange (ETDEWEB)

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

Meakin, John D. (Newark, DE); Bragagnolo, Julio (Newark, DE)

1982-01-01

 
 
 
 
201

Thin-film silicon solar cells. A review and selected trends  

International Nuclear Information System (INIS)

A case is developed for considering silicon as the prime medium-term candidate for semiconductor photovoltaic cells; the argumentation is based on other materials not being abundantly available, highly toxic and/or very expensive. Crystalline silicon solar cells have excellent efficiencies, however, according to data presented by the authors on material fluxes and energy consumption there are serious bottlenecks for this technique with respect to future large-scale applications both from an economical as well as from an ecological point of view. Thus, the authors consider thin-film silicon solar cells as the main option for large-scale energy applications in the foreseeable future. Thin-film silicon solar cells are either polycrystalline or amorphous. The first category is gaining in interest at this moment, but major technological problems remain unresolved, e.g., growth of a high-quality crystalline structure on foreign (low-cost) substrates, reduction of deposition temperature and increase of deposition rate. The second category has so far yielded only limited stable efficiencies, although progress has been recently achieved in improving the stability of solar cells using stacked or tandem/triple structures. Novel approaches to further improve the stable efficiencies, such as using low-level doping profiles within the i-layer of the p-i-n solar cell, are listed. Entirely microcrystalline p-i-n solar cells that are stable and can be deposited at low temperatures (220C) with rates up to 1 A/s by the VHF plasma deposition technique are described as further, recent contribution to thin-film silicon photovoltaic technology.

1995-01-01

202

Broadband enhancement in thin-film amorphous silicon solar cells enabled by nucleated silver nanoparticles.  

Science.gov (United States)

Recently plasmonic effects have gained tremendous interest in solar cell research because they are deemed to be able to dramatically boost the efficiency of thin-film solar cells. However, despite of the intensive efforts, the desired broadband enhancement, which is critical for real device performance improvement, has yet been achieved with simple fabrication and integration methods appreciated by the solar industry. We propose in this paper a novel idea of using nucleated silver nanoparticles to effectively scatter light in a broadband wavelength range to realize pronounced absorption enhancement in the silicon absorbing layer. Since it does not require critical patterning, experimentally these tailored nanoparticles were achieved by the simple, low-cost and upscalable wet chemical synthesis method and integrated before the back contact layer of the amorphous silicon thin-film solar cells. The solar cells incorporated with 200 nm nucleated silver nanoparticles at 10% coverage density clearly demonstrate a broadband absorption enhancement and significant superior performance including a 14.3% enhancement in the short-circuit photocurrent density and a 23% enhancement in the energy conversion efficiency, compared with the randomly textured reference cells without nanoparticles. Among the measured plasmonic solar cells the highest efficiency achieved was 8.1%. The significant enhancement is mainly attributed to the broadband light scattering arising from the integration of the tailored nucleated silver nanoparticles. PMID:22300399

Chen, Xi; Jia, Baohua; Saha, Jhantu K; Cai, Boyuan; Stokes, Nicholas; Qiao, Qi; Wang, Yongqian; Shi, Zhengrong; Gu, Min

2012-02-08

203

Broadband enhancement in thin-film amorphous silicon solar cells enabled by nucleated silver nanoparticles.  

UK PubMed Central (United Kingdom)

Recently plasmonic effects have gained tremendous interest in solar cell research because they are deemed to be able to dramatically boost the efficiency of thin-film solar cells. However, despite of the intensive efforts, the desired broadband enhancement, which is critical for real device performance improvement, has yet been achieved with simple fabrication and integration methods appreciated by the solar industry. We propose in this paper a novel idea of using nucleated silver nanoparticles to effectively scatter light in a broadband wavelength range to realize pronounced absorption enhancement in the silicon absorbing layer. Since it does not require critical patterning, experimentally these tailored nanoparticles were achieved by the simple, low-cost and upscalable wet chemical synthesis method and integrated before the back contact layer of the amorphous silicon thin-film solar cells. The solar cells incorporated with 200 nm nucleated silver nanoparticles at 10% coverage density clearly demonstrate a broadband absorption enhancement and significant superior performance including a 14.3% enhancement in the short-circuit photocurrent density and a 23% enhancement in the energy conversion efficiency, compared with the randomly textured reference cells without nanoparticles. Among the measured plasmonic solar cells the highest efficiency achieved was 8.1%. The significant enhancement is mainly attributed to the broadband light scattering arising from the integration of the tailored nucleated silver nanoparticles.

Chen X; Jia B; Saha JK; Cai B; Stokes N; Qiao Q; Wang Y; Shi Z; Gu M

2012-05-01

204

Dual gratings for enhanced light trapping in thin-film solar cells by a layer-transfer technique.  

UK PubMed Central (United Kingdom)

Thin film solar cells benefit significantly from the enhanced light trapping offered by photonic nanostructures. The thin film is typically patterned on one side only due to technological constraints. The ability to independently pattern both sides of the thin film increases the degrees of freedom available to the designer, as different functions can be combined, such as the reduction of surface reflection and the excitation of quasiguided modes for enhanced light absorption. Here, we demonstrate a technique based on simple layer transfer that allows us to independently pattern both sides of the thin film leading to enhanced light trapping. We used a 400 nm thin film of amorphous hydrogenated silicon and two simple 2D gratings for this proof-of-principle demonstration. Since the technique imposes no restrictions on the design parameters, any type of structure can be made.

Schuster CS; Kowalczewski P; Martins ER; Patrini M; Scullion MG; Liscidini M; Lewis L; Reardon C; Andreani LC; Krauss TF

2013-05-01

205

Analysis of the p+/p window layer of thin film solar cells by simulation  

International Nuclear Information System (INIS)

The application of a p+/p configuration in the window layer of hydrogenated amorphous silicon thin film solar cells is simulated and analyzed utilizing an AMPS-1D program. The differences between p+?pin configuration solar cells and pin configuration solar cells are pointed out. The effects of dopant concentration, thickness of p+-layer, contact barrier height and defect density on solar cells are analyzed. Our results indicate that solar cells with a p+?pin configuration have a better performance. The open circuit voltage and short circuit current were improved by increasing the dopant concentration of the p+ layer and lowering the front contact barrier height. The defect density at the p/i interface which exceeds two orders of magnitude in the intrinsic layer will deteriorate the cell property. (semiconductor materials)

2012-02-01

206

Pilot roll-to-roll PECVD system for fabrication of thin film Si solar cells  

Energy Technology Data Exchange (ETDEWEB)

Our aim is the development of high-throughput production technology for high efficiency, amorphous and microcrystalline thin film silicon solar cells on flexible substrates. A roll-to-roll system, the FLEXICOAT300, is developed with three deposition chambers for the continuous deposition of, respectively, n-type Si, intrinsic Si and p-type Si. Novel RF and MW sources for plasma enhanced chemical vapour deposition (PECVD) are introduced in the roll-to-roll coater. The first trial depositions of a-Si solar cells show a promising efficiency of > 4%.

Van Aken, B.B.; Devilee, C.; Doerenkaemper, M.S.; Heijna, M.; Loeffler, J.; Soppe, W.J. [ECN Solar Energy, Petten (Netherlands)

2008-03-15

207

Research and developmental study on MIS thin film solar cells of amorphous hydrogenated silicon, part 2  

Science.gov (United States)

The suitability of sputtered hydrogenated amorphous silicon (a-Si:H) layers for thin film solar cells is studied. The undoped intrinsic a-Si:H layers are optimized with respect to efficiency parameters, time stability, and resistance to sunlight. Schottky diodes and n-i-p layer structures were tested. Schottky diode efficiency can reach 6.8 mA/sq cm with a 2% improvement. Recombination effects in Schottky diodes with antireflection layers have to be overcome. The n-i-p layer structures have higher Voc values and lower JSC values than Schottky diodes. Further development of sputtered amorphous silicon solar cells is recommended.

Jaeger, H.; Engeman, D.; Ilgenstein, M.; Roessler, W.

1984-12-01

208

Broad-band anti-reflection coupler for a : Si thin-film solar cell  

International Nuclear Information System (INIS)

This work numerically demonstrates a new anti-reflection coupler (ARC) with high coupling efficiency in a Si substrate solar cell. The ARC in which the grating is integrated on a glass encapsulation and a three-layer impedance match layer is proposed. A coupling efficiency of 90% is obtained at wavelengths between 350 and 1200 nm in the TE and TM modes when the incident angle is less than 300. In comparison with a 1?m absorber layer, the integrated absorption of an a-Si thin-film solar cell without a new ARC is doubled, at long wavelengths (750 nm ? ? ? 1200 nm), as calculated by FDTD method

2007-02-07

209

Commercial white paint as back surface reflector for thin-film solar cells  

Energy Technology Data Exchange (ETDEWEB)

In this work, commercially available white paint is applied as a pigmented diffuse reflector (PDR) on the rear surface of thin-film crystalline silicon (c-Si) solar cells with a silicon thickness in the 1-2 {mu}m range. We show that white paint increases the short-circuit current density of the solar cells enormously, with a boost of 41% observed for very thin planar solar cells illuminated with the global AM1.5 solar spectrum. We also show that white paint is a better back surface reflector (BSR) than aluminium, air, a transparent conductive oxide (TCO)/aluminium stack, and even a detached aluminium mirror. While previous studies have investigated the influence of PDRs on silicon solar cells with thicknesses of over 27 {mu}m, this work closes the gap that has existed for much thinner cells. (author)

Berger, Olaf; Inns, Daniel; Aberle, Armin G. [Photovoltaics Centre of Excellence, The University of New South Wales, UNSW, Sydney, NSW 2052 (Australia)

2007-08-15

210

Fabrication and characterization of ZnTe/CdSe thin film solar cells  

Energy Technology Data Exchange (ETDEWEB)

Thin film solar cells have been prepared and investigated by using indium-doped n-CdSe in conjunction with p-ZnTe. The films are prepared on indium tin oxide (ITO) coated glass substrates by the thermal evaporation. Thin film layers have been deposited without breaking vacuum by utilizing a mask rotating system. Silver has been used as a stimulator for bringing improvement in the crystallinity and electrical behaviour of ZnTe thin films. Indium is used for obtaining the back ohmic contacts. The solar cells thus produced have been characterized by I-V-, C-V-, and spectral response measurements. The maximum open circuit voltage, the short circuit current density, and the efficiency are obtained as 415 mV, 11.60 mA cm[sup -2] and 1.86%, respectively under 100 mW cm[sup -2] input optical power. The diffusion potential and depletion width are found to be 1.42 eV and 21 nm, respectively. (orig.)

Patel, N.G. (Sardar Patel Univ., Vallabh Vidyanagar, Gujarat (India). Dept. of Electronics); Panchal, C.J. (Sardar Patel Univ., Vallabh Vidyanagar, Gujarat (India). Dept. of Electronics); Makhija, K.K. (Sardar Patel Univ., Vallabh Vidyanagar, Gujarat (India). Dept. of Electronics); Patel, P.G. (Sardar Patel Univ., Vallabh Vidyanagar, Gujarat (India). Dept. of Electronics); Patel, S.S. (Sardar Patel Univ., Vallabh Vidyanagar, Gujarat (India). Dept. of Electronics)

1994-01-01

211

Neutrons and photons in materials research for thin film solar cells  

Energy Technology Data Exchange (ETDEWEB)

The understanding of the interplay between structural and electronic properties of photovoltaic materials as well as a deeper insight into growth pathways and phase formation kinetics of the absorber layer in a thin film solar cell give a crucial contribution to the continuous improvement of the solar cell efficiency. Among the various experimental methods used for the investigation of the structure and microstructure of photovoltaic materials, neutron, and X-ray (photon) scattering are key techniques of choice. Both techniques are complementary, which is demonstrated in the present paper. Neutron powder diffraction is used to detect different kinds of intrinsic point defects in chalcopyrite type and kesterite type semiconductors. The calculated defect concentrations may lead to the expectation of a clustering of anti-site defects and vacancy to the electrical inactive defect pairs (2V{sub Cu}+In{sub Cu}) and (In{sub Cu}+Cu{sub In}). By the means of energy dispersive X-ray diffraction (EDXRD) phase formations and grain growth in thin films are studied in real time. The potential of EDXRD for in situ studies of reactions during the formation of chalcopyrite thin films is demonstrated. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Schorr, Susan [Institute of Geological Sciences, Freie Universitaet Berlin (Germany); Stephan, Christiane; Mainz, Roland; Rodriguez-Alvarez, Humberto; Tovar, Michael [Helmholtz-Zentrum Berlin fuer Materialien und Energie (Germany)

2011-08-15

212

Chemical synthesis of p-type nanocrystalline copper selenide thin films for heterojunction solar cells  

International Nuclear Information System (INIS)

Nanocrystalline thin films of copper selenide have been grown on glass and tin doped-indium oxide substrates using chemical method. At ambient temperature, golden films have been synthesized and annealed at 200 deg. C for 1 h and were examined for their structural, surface morphological and optical properties by means of X-ray diffraction (XRD), scanning electron microscopy and UV-vis spectrophotometry techniques, respectively. Cu2-xSe phase was confirmed by XRD pattern and spherical grains of 30 4 - 40 4 nm in size aggregated over about 130 10 nm islands were seen by SEM images. Effect of annealing on crystallinity improvement, band edge shift and photoelectrochemical performance (under 80 mW/cm2 light intensity and in lithium iodide electrolyte) has been studied and reported. Observed p-type electrical conductivity in copper selenide thin films make it a suitable candidate for heterojunction solar cells.

2006-12-15

213

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)

2009-01-01

214

Nano-granular indium sulfide layers for thin film solar cells  

International Nuclear Information System (INIS)

Nano-granular indium sulfide films were prepared by thermal evaporation onto quartz and glass substrates kept at TS = 220-240 degrees during the deposition process. High transmittance of the nano-granular indium sulfide films in the visible region has been observed. Correlations between optical properties and morphology of film samples with various thickness have been investigated. Modification of the form and short-wavelength shift of the band edge occur simultaneously upon decreasing of the film thickness from 800 nm up to 30 nm, and the involved mechanisms have been explained. The results indicate that the former effects are assigned to multicomponent composition of the investigated films and that the obtained nanogranular thin films might be proposed as low-cost buffer materials for high-efficient thin-film solar cells with chalcopyrite absorber layers. (authors)

2006-01-01

215

Characterization of chemical bath deposited buffer layers for thin film solar cell applications  

Energy Technology Data Exchange (ETDEWEB)

Cadmium sulfide (CdS), indium sulfide (In{sub 2}S{sub 3}) and zinc sulfide (ZnS) thin films have been deposited by chemical bath deposition (CBD) for buffer layer applications in Cu-chalcopyrite-based thin film solar cells. Films were characterized by scanning electron microscopy (SEM), UV-Vis transmission, X-ray photoelectron spectroscopy (XPS), grazing-incidence X-ray diffraction (GIXRD), and spectroscopic ellipsometry. Results indicate CdS can be deposited with low oxygen content and high light transmission over 245-1700 nm. CBD-ZnS and CBD-InS both exhibit 5-10% less light transmission than CdS in the same thickness range. In terms of light transmission and degree of impurities CdS appears to be a better buffer material than CBD-ZnS or CBD-InS. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

Dwyer, D.; Efstathiadis, H.; Haldar, P. [College of Nanoscale Science and Engineering, University at Albany - State University of New York, 257 Fuller Rd., Albany, NY 12203 (United States); Sun, R. [Angstrom Sun Technologies Inc., 33 Nagog Park, Acton, MA 01720 (United States)

2010-10-15

216

Recent progress and critical issues in thin film polycrystalline solar cells and modules  

Energy Technology Data Exchange (ETDEWEB)

Thin film CdTe and CuInSe{sub 2} based solar cells have reported efficiencies of over 15% and 17% respectively for small area laboratory devices and over 10% for prototype modules. In the present article, an approach to translate laboratory results to the development of large scale module manufacturing facilities is discussed, and critical issues associated with the development of CuInSe{sub 2} and CdTe thin film polycrystalline module manufacturing are identified. For CuInSe{sub 2} based PV, the analysis and modeling used in the design and development of a continuous, commercial scale deposition system is presented. For CdTe based PV, the issues associated with the back contact are discussed with particular emphasis on the development of a diffused Cu contact.

Birkmire, R.W. [Univ. of Delaware, Newark, DE (United States). Inst. of Energy Conversion

1997-12-31

217

Thin-Film Solar Cells Based on the Polycrystalline Compound Semiconductors CIS and CdTe  

Directory of Open Access Journals (Sweden)

Full Text Available Thin-film photovoltaic modules based on Cu-In-Ga-Se-S (CIS) and CdTe are already being produced with high-quality and solar conversion efficiencies of around 10%, with values up to 14% expected in the near future. The integrated interconnection of single cells into large-area modules of 0.6×1.2m2 enables low-cost mass production, so that thin-film modules will soon be able to compete with conventional silicon-wafer-based modules. This contribution provides an overview of the basic technologies for CdTe and CIS modules, the research and development (R&D) issues, production technology and capacities, the module performance in long-term outdoor testing, and their use in installations.

Michael Powalla; Dieter Bonnet

2007-01-01

218

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

Science.gov (United States)

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

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

2013-05-07

219

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

UK PubMed Central (United Kingdom)

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.

Cho JW; Ismail A; Park SJ; Kim W; Yoon S; Min BK

2013-05-01

220

First-Principles Study of Back Contact Effects on CdTe Thin Film Solar Cells  

Energy Technology Data Exchange (ETDEWEB)

Forming a chemically stable low-resistance back contact for CdTe thin-film solar cells is critically important to the cell performance. This paper reports theoretical study of the effects of the back-contact material, Sb{sub 2}Te{sub 3}, on the performance of the CdTe solar cells. First-principles calculations show that Sb impurities in p-type CdTe are donors and can diffuse with low diffusion barrier. There properties are clearly detrimental to the solar-cell performance. The Sb segregation into the grain boundaries may be required to explain the good efficiencies for the CdTe solar cells with Sb{sub 2}Te{sub 3} back contacts.

Du, Mao-Hua [ORNL

2009-01-01

 
 
 
 
221

Epitaxially grown crystalline silicon thin-film solar cells reaching 16.5% efficiency with basic cell process  

International Nuclear Information System (INIS)

We report about the current performance of crystalline silicon thin-film (cSiTF) solar cells that are a very attractive alternative to conventional wafer-based silicon solar cells if sufficiently high cell efficiencies are achieved at acceptable cost of production. Applying a standard cell process (diffused POCl3 emitter, front contacts by photolithography, no surface texture) to thin-films deposited with a lab-type reactor, specifically designed for high-throughput photovoltaic applications, on highly-doped Cz substrates we routinely obtain efficiencies above 16%. On 1 ? cm FZ material substrates we reach efficiencies up to 18.0%, which is among the highest thin-film efficiencies ever reported. Additionally, a comparison to microelectronic-grade epitaxially grown cSiTF material underlines the excellent electrical quality of the epitaxial layers deposited.

2011-03-01

222

Monolithic series interconnection for thin-film silicon solar cells on steel foil  

Energy Technology Data Exchange (ETDEWEB)

Roll-to-roll production facilitates flexible PV modules and a significant decrease of production costs for thin-film silicon solar cells. However, no standard processes for monolithic series interconnection on foil substrates are readily available. ECN is currently developing the technology and setting up a pilot line for the production of single junction and tandem solar cells based on microcrystalline and amorphous silicon on steel foil substrates. To allow monolithic series interconnection on these electrically conducting substrates, an insulating layer is required. In the presented module concept, first all layers of the solar cell are deposited, and after that series interconnection is realized by three depth selective laser scribes which are filled by insulating and electrically conductive inks. In this paper, we present the current status of development for all key technologies required for the presented module concept: comprising a pinhole free insulating layer, an embossing process for this layer to apply light trapping textures on sub-micrometer scale, depth selective laser scribing by solid state YAG lasers, and screen printing pastes and processes for insulating and conductive inks curable at low temperature. First test samples have demonstrated the feasibility of the depth selective laser scribing and electrical series interconnection with the developed screen printing processes. Interconnection losses below 10% with respect to individual cells are anticipated when combining the presented processes for actual fabrication of monolithically interconnected thin-film silicon solar cells on steel foil.

Loeffler, J.; De Keijzer, M.A.; Dissel, M.; Heijna, M.; Spaeth, M.; Soppe, W.J. [ECN Solar Energy, Petten (Netherlands); Finck, C.; Wutz, M. [Rofin / Baasel Lasertech, Starnberg (Germany)

2008-02-15

223

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

224

Damage mechanisms in thin film solar cells during sputtering deposition of transparent conductive coatings  

International Nuclear Information System (INIS)

Amorphous silicon (a-Si) based thin film solar cell grown on flexible stainless steel substrate is one of the most promising energy conversion devices in the future. This type of solar cell uses a transparent conductive oxide (TCO) film as top electrode. It has been a widely accepted opinion that the radio frequency sputtering deposition of the TCO film produces a higher yield than direct current sputtering, and the reason is not clear. Here we show that the damage to the solar cell during the sputtering process is caused by a reverse bias applied to the n-i-p junction. This reverse bias is related to the characteristics of plasma discharge. The mechanism we reveal may significantly affect the solar cell process.

2009-02-01

225

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.

2010-10-01

226

Enhanced photocurrent in thin-film amorphous silicon solar cells via shape controlled three-dimensional nanostructures.  

UK PubMed Central (United Kingdom)

In this paper, we have explored manufacturable approaches to sub-wavelength controlled three-dimensional (3D) nano-patterns with the goal of significantly enhancing the photocurrent in amorphous silicon solar cells. Here we demonstrate efficiency enhancement of about 50% over typical flat a-Si thin-film solar cells, and report an enhancement of 20% in optical absorption over Asahi textured glass by fabricating sub-wavelength nano-patterned a-Si on glass substrates. External quantum efficiency showed superior results for the 3D nano-patterned thin-film solar cells due to enhancement of broadband optical absorption. The results further indicate that this enhanced light trapping is achieved with minimal parasitic absorption losses in the deposited transparent conductive oxide for the nano-patterned substrate thin-film amorphous silicon solar cell configuration. Optical simulations are in good agreement with experimental results, and also show a significant enhancement in optical absorption, quantum efficiency and photocurrent.

Hilali MM; Yang S; Miller M; Xu F; Banerjee S; Sreenivasan SV

2012-10-01

227

Shrinking and growing: grain boundary density reduction for efficient polysilicon thin-film solar cells.  

Science.gov (United States)

Polycrystalline Si (poly-Si) thin-film, due to its low Si consumption, low substrate cost, and good stability, is an attractive candidate for cost-effective solar cells, but the as-deposited poly-Si typically has a columnar structure with grain boundaries in between, severely limiting the efficiency of the poly-Si. Here, we report a micropillar poly-Si solar cell that utilizes the columnar structure of the as-deposited poly-Si grains. We first formed submicrometer diameter poly-Si pillars, smaller than the initial grain sizes, and used these pillars as the seeds for the subsequent epitaxial growth of Si, which effectively reduces grain boundary density in the final poly-Si crystal. In addition, the vertically aligned micropillar arrays form radial p-n junctions that further mitigate the grain boundary recombination losses by improving the light absorption and charge-carrier collection efficiencies. Consequently, the maximum efficiency of micropillar poly-Si thin-film solar cells is 6.4%, that is, ?1.5 times higher than that of the planar cells. PMID:23167740

Kim, Dong Rip; Lee, Chi Hwan; Weisse, Jeffrey M; Cho, In Sun; Zheng, Xiaolin

2012-11-29

228

Shrinking and growing: grain boundary density reduction for efficient polysilicon thin-film solar cells.  

UK PubMed Central (United Kingdom)

Polycrystalline Si (poly-Si) thin-film, due to its low Si consumption, low substrate cost, and good stability, is an attractive candidate for cost-effective solar cells, but the as-deposited poly-Si typically has a columnar structure with grain boundaries in between, severely limiting the efficiency of the poly-Si. Here, we report a micropillar poly-Si solar cell that utilizes the columnar structure of the as-deposited poly-Si grains. We first formed submicrometer diameter poly-Si pillars, smaller than the initial grain sizes, and used these pillars as the seeds for the subsequent epitaxial growth of Si, which effectively reduces grain boundary density in the final poly-Si crystal. In addition, the vertically aligned micropillar arrays form radial p-n junctions that further mitigate the grain boundary recombination losses by improving the light absorption and charge-carrier collection efficiencies. Consequently, the maximum efficiency of micropillar poly-Si thin-film solar cells is 6.4%, that is, ?1.5 times higher than that of the planar cells.

Kim DR; Lee CH; Weisse JM; Cho IS; Zheng X

2012-12-01

229

Understanding of photocurrent enhancement in real thin film solar cells: towards optimal one-dimensional gratings.  

UK PubMed Central (United Kingdom)

Despite the progress in the engineering of structures to enhance photocurrent in thin film solar cells, there are few comprehensive studies which provide general and intuitive insight into the problem of light trapping. Also, lack of theoretical propositions which are consistent with fabrication is an issue to be improved. We investigate a real thin film solar cell with almost conformal layers grown on a 1D grating metallic back-reflector both experimentally and theoretically. Photocurrent increase is observed as an outcome of guided mode excitation in both theory and experiment by obtaining the external quantum efficiency of the cell for different angles of incidence and in both polarization directions. Finally, the effect of geometrical parameters on the short circuit current density of the device is investigated by considering different substrate shapes that are compatible with solar cell fabrication. Based on our simulations, among the investigated shapes, triangular gratings with a very sharp slope in one side, so called sawtooth gratings, are the most promising 1D gratings for optimal light trapping.

Naqavi A; Sderstrm K; Haug FJ; Paeder V; Scharf T; Herzig HP; Ballif C

2011-01-01

230

An effective use of nanocrystalline CdO thin films in dye-sensitized solar cells  

Energy Technology Data Exchange (ETDEWEB)

Thin films of cadmium oxide (CdO) were synthesized by layer-by-layer deposition method on indium doped tin oxide (ITO) substrates. Post-deposition annealing at 250{sup o}C for 24h produced pure phase CdO films by removal of trace amount of cadmium hydroxide, as confirmed from X-ray diffractogram. First time employment of CdO in place of TiO{sub 2} in dye-sensitized solar cells is reported to check feasibility and cell performance. A dye-sensitized nanocrystalline CdO photo-electrode was obtained by adsorbing cis-dithiocyanato (4,4'-dicarboxylic acid-2,2'-bipyridide) ruthenium (II) (N3) dye by keeping at 45{sup o}C for 20h. The efficiency of dye-sensitized nanocrystalline CdO thin film solar cell was increased from 0.24% to 2.95% due to dye adsorption. This must be highest reported conversion efficiency for other metal oxides than TiO{sub 2}based dye-sensitized solar cells. (author)

Mane, R.S.; Han, Sung-Hwan [Inorganic Nano-Materials, Department of Chemistry, Hanyang University, Sungdong-Ku, Haengdang dong 17, Seoul 133-791 (Korea, Republic of); Pathan, H.M.; Lokhande, C.D. [Thin Film Physics Laboratory, Department of Physics, Shivaji University, Kolhapur 416 004 (India)

2006-02-15

231

Thermally evaporated thin films of SnS for application in solar cell devices  

International Nuclear Information System (INIS)

SnS (tin sulphide) is of interest for use as an absorber layer and the wider energy bandgap phases e.g. SnS2, Sn2S3 and Sn/S/O alloys of interest as Cd-free buffer layers for use in thin film solar cells. In this work thin films of tin sulphide have been thermally evaporated onto glass and SnO2:coated glass substrates with the aim of optimising the properties of the material for use in photovoltaic solar cell device structures. In particular the effects of source temperature, substrate temperature, deposition rate and film thickness on the chemical and physical properties of the layers were investigated. Energy dispersive X-ray analysis was used to determine the film composition, X-ray diffraction to determine the phases present and structure of each phase, transmittance and reflectance versus wavelength measurements to determine the energy bandgap and scanning electron microscopy to observe the surface topology and topography and the properties correlated to the deposition parameters. Using the optimised conditions it is possible to produce thin films of tin sulphide that are pinhole free, conformal to the substrate and that consist of densely packed columnar grains. The composition, phases present and the optical properties of the layers deposited were found to be highly sensitive to the deposition conditions. Energy bandgaps in the range 1.55 eV-1.7 eV were obtained for a film thickness of 0.8 ?m, and increasing the film thickness to > 1 ?m resulted in a reduction of the energy bandgap to less than 1.55 eV. The applicability of using these films in photovoltaic solar cell device structures is also discussed.

2009-07-01

232

One-dimensional simulation study of microcrystalline silicon thin films for solar cell and thin film transistor applications using AMPS-1D  

Energy Technology Data Exchange (ETDEWEB)

Electronic transport in hydrogenated microcrystalline silicon ({mu}c-Si:H) films largely depends on size and shape of small crystallites columnar grains, the fraction of amorphous silicon (a-Si:H) matrix, and the highly defective grain boundaries (GBs). Based on these we describe two simple 1-D models of {mu}c-Si:H depending upon the conduction path. Two applications of these models are presented using AMPS-1D. First, we study the electronic transport in intrinsic {mu}c-Si:H for thin-film transistor (TFT) application. Second, we analyze the performance of thin film p-i-n {mu}c-Si:H solar cells with varying column heights in the intrinsic {mu}c-Si:H layer. Such a study should lead to the identification of optimum process conditions of the preparation of these films by the Cat-CVD process.

Tripathi, S. [Semiconductor Thin Films and Plasma Processing Laboratory, Department of Metallurgical Engineering and Materials Science (India); Venkataramani, N. [Advanced Center for Research in Electronics, Indian Institute of Technology, Bombay, Mumbai-400076 (India)]. E-mail: ramani@acre.iitb.ac.in; Dusane, R.O. [Semiconductor Thin Films and Plasma Processing Laboratory, Department of Metallurgical Engineering and Materials Science (India); Schroeder, B. [Department of Physics and Research Center of Materials Science, University of Kaiserslautern, Kaiserslautern (Germany)

2006-04-20

233

Band gap engineering of RF-sputtered CuInZnSe{sub 2} thin films for indium-reduced thin-film solar cell application  

Energy Technology Data Exchange (ETDEWEB)

We demonstrated the preparation and characterization of radio frequency (RF)-sputtered CuInZnSe{sub 2} thin films for indium-reduced thin-film solar cell application. Sputtering targets composed of high-purity CuSe, InSe and ZnSe powders were employed for preparing CuInZnSe{sub 2} films with various band gaps. Under an optimum condition, an increase of zinc concentration in the film could reduce indium approximately to 45%. The structure of the films showed a chalcopyrite phase with a predominant (1 1 2) reflection. The p-type CuInZnSe{sub 2} films exhibited a shift of optical transmittance to a lower wavelength and the band gap could be engineered from 1.0 to 1.25 eV in proportion with increasing zinc concentration. (author)

Wibowo, Rachmat Adhi; Kim, Kyoo Ho [Department of Materials Science and Engineering, Yeungnam University, 214-1 Daedong, Gyeongsan, Gyeongbuk 712-749 (Korea)

2009-06-15

234

Efficiency limitations of thermally evaporated thin-film SnS solar cells  

Science.gov (United States)

Thin-film solar cells with SnS as absorber material were prepared by thermal evaporation of SnS. The cells were built in a superstrate configuration using Al?:?ZnO coated glass as front contact with an intrinsic ZnO buffer layer and/or CdS window layer and a gold back contact. The IV-characteristics and external quantum efficiency of the devices were determined. The best CdS/SnS solar cell showed a conversion efficiency of 1.6%, a short circuit current density of 19 mA cm?2 and an open circuit voltage of 217 mV. Moreover, band alignments at the interfaces AZO/SnS, CdS/SnS and SnS/Au were determined with in situ x-ray photoelectron spectroscopy to correlate the open circuit voltage limitations of the investigated solar cell device structures.

Schneikart, A.; Schimper, H.-J.; Klein, A.; Jaegermann, W.

2013-07-01

235

Contact system for thin film solar cells. Kontaktierungssystem fuer Duennschicht-Solarzellen  

Energy Technology Data Exchange (ETDEWEB)

The contact system for thin film solar cells is proposed, which ensures that a load charge transport free of a barrier layer occurs from the side of the semiconductor layer towards the light source to the front contact, so that there is no long term effect of the front contact on the semiconductor layer. For this purpose, the front contact is passivated relative to the semiconductor layer at least by adaptation of its chemical potential in the contact area to the chemical potential of the semiconductor layer or by building up a chemically inert system as a reaction barrier between the front contact and the semiconductor layer.

Hewig, G.; Huschka, H.; Schurich, B.; Woerner, D.

1985-05-09

236

Enhanced zone-melting recrystallization for crystalline silicon thin-film solar-cells  

Energy Technology Data Exchange (ETDEWEB)

For zone-melting recrystallization of thin Si films the effects of preheating temperature and focussed lamp intensity on solidification front morphology and defect:structure are studied. Subgrain boundaries are the dominating defect type and limit the base diffusion length. In-situ observation of the melt zone shows that cellular growth leads to films with regular spaced subgrain boundaries and low defect density. These films are preferentially (100)-orientated. Crystalline Si thin film solar cells with a random pyramid front side texture were processed from this material resulting in efficiencies up to 12.8%. (orig.)

Kieliba, T.; Reber, S. [Fraunhofer-Institut fuer Solare Energiesysteme (ISE), Freiburg im Breisgau (Germany)

2000-07-01

237

Analysis of the diode characteristics of thin film solar cells based on CdTe  

International Nuclear Information System (INIS)

A physical approach to the optimization of photoelectric processes in thin film multilayer systems has been developed. By means of a simulation of the influence of light-diode characteristics on the efficiency factor, it is concluded that the optimization of the photoelectric processes in ITO/CdS/CdTe/Cu/Au film solar cells is mainly determined by two competing physical mechanisms: an increase in the efficiency of the process of distribution of nonequilibrium charge carriers and a reduction in the efficiency of their generation, as the CdS layer thickness grows.

2004-01-01

238

Non-Uniformities in Thin-Film Cadmium Telluride Solar Cells Using Electroluminescence and Photoluminescence  

Energy Technology Data Exchange (ETDEWEB)

It is the purpose of this research to develop specific imaging techniques that have the potential to be fast, inline tools for quality control in thin-film CdTe solar cells. Electroluminescence (EL) and photoluminescence (PL) are two techniques that are currently under investigation on CdTe small area devices made at Colorado State University. It is our hope to significantly advance the understanding of EL and PL measurements as applied to CdTe. Qualitative analysis of defects and non-uniformities is underway on CdTe using EL, PL, and other imaging techniques.

Zaunbrecher, K.; Johnston, S.; Yan, F.; Sites, J.

2011-01-01

239

Non-Uniformities in Thin-Film Cadmium Telluride Solar Cells Using Electroluminescence and Photoluminescence: Preprint  

Energy Technology Data Exchange (ETDEWEB)

It is the purpose of this research to develop specific imaging techniques that have the potential to be fast, in-line tools for quality control in thin-film CdTe solar cells. Electroluminescence (EL) and photoluminescence (PL) are two techniques that are currently under investigation on CdTe small area devices made at Colorado State University. It is our hope to significantly advance the understanding of EL and PL measurements as applied to CdTe. Qualitative analysis of defects and non-uniformities is underway on CdTe using EL, PL, and other imaging techniques.

Zaunbrecher, K.; Johnston, S.; Yan, F.; Sites, J.

2011-07-01

240

Optical properties of alumina ceramics as a substrate of thin film solar cells  

Energy Technology Data Exchange (ETDEWEB)

For full understanding of the optical properties of alumina ceramics which are used as a substrate of thin film c-Si solar cells, we carried out computer simulations of diffuse reflectance and measurements of angle-resolved reflectance. As the result of the computer simulations, we obtained a theoretical expression for the reflectance properties of alumina ceramics with flat surface. The expression can be applied for the measured reflectance of alumina ceramics with rough surface when an effect of surface condition was taken into account

Tazawa, Masato; Yoshimura, Kazuki; Igarashi, Kazuo; Tanemura, Sakae [National Industrial Research Institute of Nagoya, Nagoya (Japan)

1997-10-14

 
 
 
 
241

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

UK PubMed Central (United Kingdom)

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.

Martella C; Chiappe D; Delli Veneri P; Mercaldo LV; Usatii I; Buatier de Mongeot F

2013-06-01

242

Large-grained polycrystalline silicon on glass for thin-film solar cells  

International Nuclear Information System (INIS)

We have investigated the formation of large-grained polycrystalline silicon (poly-Si) films on glass for thin-film solar cells using the 'seed layer concept' which is based on the epitaxial thickening of a thin large-grained poly-Si template (seed layer). Due to the glass substrate all process steps are limited to a temperature of about 600 deg. C. The aluminium-induced layer exchange (ALILE) process based on the aluminium-induced crystallisation (AIC) of amorphous Si has been used to prepare p+-type seed layers featuring large grains and a high preferential (100) orientation of the surface. The seed layers have been thickened by electron cyclotron resonance chemical vapour deposition (ECRCVD) to form the p-type absorber of the solar cell. First poly-Si thin-film solar cell structures have been prepared by deposition of an n+-type a-Si : H emitter. So far an open circuit voltage of 284 mV has been reached without any additional treatments like defect annealing and defect passivation.

2006-07-26

243

Doping-free fabrication of silicon thin films for schottky solar cell.  

UK PubMed Central (United Kingdom)

Thin film Schottky solar cells were fabricated without doping processes, which may provide an alternative approach to the conventional thin film solar cells in the n-i-p configuration. A thin Co layer was coated on a substrate, which worked as a back contact metal and then Si film was grown above it. Deposition condition may modulate the Si film structure to be a fully amorphous Si (a-Si) or a mixing of microcrystalline Si (mc-Si) and a-Si. A thin Au layer was deposited above the grown Si films, which formed a Schottky junction. Two types of Schottky solar cells were prepared on a fully a-Si film and a mixing of mc-Si and a-Si film. Under one sun illumination, the mixing of mc-Si and a-Si device provided 35% and 68.4% enhancement in the open circuit voltage and fill factor compared to that of the amorphous device.

Yun JH; Park YC; Yi J; Woo CS; Kim J

2012-02-01

244

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

1995-08-01

245

Band Gap Profiling and High Speed Deposition of Cu(In,Ga)Se2 for Thin Film Solar Cells  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The Cu(In,Ga)Se2-based thin film solar cell is a promising candidate for becoming one of the more important solar cell technologies in the near future. In order to realize such a development a significant reduced production cost of the Cu(In,Ga)Se2 (CIGS) layer is needed. Th...

Lundberg, Olle

246

CdTe thin film solar cells prepared by a low-temperature deposition method  

Energy Technology Data Exchange (ETDEWEB)

Low-temperature vacuum deposition instead of the commonly used vacuum deposition at high substrate temperatures has been applied to prepare high efficiency (CdS/CdTe) solar cells. CdS and CdTe thin films have been subsequently deposited on SnO{sub 2}/Corning 7059 glass substrates and examined by using scanning electron microscopy (SEM) and grazing incidence X-ray diffraction (GIXRD) techniques. It has been found that CdTe and CdS films deposited at low substrate temperature (218 K) have very similar grain sizes and surface morphology, necessary for high efficiency photovoltaic performance of the resultant device structures. Particularly, the obtained solar cells have shown efficiencies of more than 14%. The applied preparation method can be regarded as promising for high efficiency CdTe-based solar cell fabrication. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

Novruzov, V.D.; Gorur, O.; Tomakin, M. [Rize University, 53100 Rize (Turkey); Fathi, N.M.; Bayramov, A.I.; Mamedov, N. [Institute of Physics, Azerbaijan National Academy of Sciences, H. Javid ave. 33, 1143 Baku (Azerbaijan); Schorr, S. [Institute of Geological Sciences, Free University Berlin, Malteserstr. 74-100, 12249 Berlin (Germany)

2010-03-15

247

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

Energy Technology Data Exchange (ETDEWEB)

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 J{sub sc} (up to 11.4 mA/cm{sup 2}) and initial tandem-cell conversion efficiency (up to 11.3%)

Smirnov, Vlad [IEF-5 Photovoltaik, Forschungszentrum Juelich GmbH, Leo-Brandt Str., D-52425 Juelich (Germany)], E-mail: v.smirnov@fz-juelich.de; Das, Chandan; Melle, Thomas; Lambertz, Andreas; Huelsbeck, Markus; Carius, Reinhard; Finger, Friedhelm [IEF-5 Photovoltaik, Forschungszentrum Juelich GmbH, Leo-Brandt Str., D-52425 Juelich (Germany)

2009-03-15

248

Fabrication, characterization and interface study of CdS/CdTe thin film solar cells  

International Nuclear Information System (INIS)

[en]Thin films of CdTe and ZnTe are optically and electrically characterized during the course of this research work. Various samples are of CdS/CdTe solar cells are prepared on glass and copper substrate. These samples are then subjected to electrical measurements. For the interface study of CdS/CdTe junction, thin films of CdS CdTe are fabricated on single crystal Si substrate to form CdTe/CdS/Si and ZnTe/CdTe/CdS/Si samples. These samples are analyzed for interface study by using Auger Electron Spectroscopy. Finally, the results obtained by interface study are compared with that for electrical measurements obtained earlier, and it is found that the open circuit voltage for the solar cells is close to the optimum value but the short circuit current values for the same cells are away from the optimum value. The is because of the formation of a resistive layer in the vicinity of the junction of the cell due to unwanted mixing taking place in these samples especially in the CdTe/CdS junction. (author)

2001-01-01

249

Thin film polycrystalline silicon solar cells. Second technical progress report, July 16, 1980-October 15, 1980  

Energy Technology Data Exchange (ETDEWEB)

The objectives of this contract are to fabricate large area thin film silicon solar cells with AM1 efficiency of 10% or greater with good reproducibility and good yield and to assess the feasibility of implementing this process for manufacturing solar cells at a cost of $300/kWe. Efforts have been directed to the purification of metallurgical silicon, the preparation and characterization of substrates and epitaxial silicon layers, and the fabrication and characterization of solar cells. The partial purification of metallurgical silicon by extraction with aqua regia has been further investigated in detail, and the resulting silicon was analyzed by the atomic absorption technique. The unidirectional solidification of aqua regia-extracted metallurgical silicon on graphite was used for the preparation of substrates, and the impurity distribution in the substrate was determined and compared with the impurity content in metallurgical silicon. The effects of heat treatment on the impurity distribution in the substrate and in the epitaxial layer have also been investigated. Large area (30 to 60 cm/sup 2/) solar cells have been prepared from aqua regia-extracted metallurgical silicon substrates by depositing a p-n junction structure using the thermal reduction of trichlorosilane containing appropriate dopants. The AM1 efficiencies are about 9% for cells of 30 to 35 cm/sup 2/ area. Larger area, 60 cm/sup 2/, thin film solar cells have been fabricated for the first time, and their AM1 efficiencies are slightly higher than 8%. The spectral response, minority carrier diffusion length, and I/sub sc/-V/sub oc/ relation in a number of solr cells have been measured.

None

1980-10-01

250

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

Energy Technology Data Exchange (ETDEWEB)

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.)

Wagner, H.

2001-07-01

251

Generation of electrical defects in ion beam assisted deposition of Cu(In,Ga)Se2 thin film solar cells  

International Nuclear Information System (INIS)

Thin films of Cu(In,Ga)Se2 (CIGS) absorber layers for thin film solar cells have been manufactured on polyimide foil in a low temperature, ion beam assisted co-evaporation process. In the present work a set of CIGS thin films was produced with varying selenium ion energy. Solar cell devices have been manufactured from the films and characterized via admittance spectroscopy and capacitance-voltage profiling to determine the influence of the selenium ion energy on the electric parameters of the solar cells. It is shown that the impact of energetic selenium ions in the CIGS deposition process leads to a change in the activation energy and defect density and also in the spatial distribution of electrically active defects. For the interpretation of the results two defect models are taken into account.

2011-08-31

252

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%.

2009-04-30

253

Effect of CdCl2 annealing treatment on CdS thin films and CdTe/CdS thin film solar cells  

International Nuclear Information System (INIS)

In order to study the effect of CdCl2 annealing treatment on thin CdS films and CdTe/CdS thin film solar cells, a comparative study was carried out on three types of CdTe/CdS solar cells, which had different kinds of CdS window layer: as-deposited CdS, air-annealed CdS without CdCl2 pre-coating, and CdCl2-annealed CdS. When annealed in air the CdS film was partially oxidated to CdO and CdSO4. These oxides increased the series resistance of the CdTe solar cell and led to the lowest fill factor. The presence of CdCl2 on the surface of a CdS thin film during heat treatment in air protected it from oxidation and promoted the recrystallization of the CdS film, resulting in large and closely packed grains with a grain size of ? 50 -150 nm. CdTe/CdS solar cell with such a kind of CdS window layer showed the largest short circuit current and highest conversion efficiency of 12.4%. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

2010-06-04

254

Asymmetric intermediate reflector for tandem micromorph thin film silicon solar cells  

Science.gov (United States)

The micromorph solar cell (stack of amorphous and microcrystalline cells) concept is the key for achieving high efficiency stabilized thin film silicon solar cells. We introduce a device structure that allows a better control of the light in-coupling into the two subcell components. It is based on an asymmetric intermediate reflector, which increases the effective thickness of the a-Si:H by a factor of more than three. Hence, the a-Si:H thickness reduction diminishes the light induced degradation, and micromorph tandem cells with 11.2% initial and 9.8% stabilized efficiencies (1000 h, 50 C, and 100 mW/cm2) are made on plastic substrates with Tg<180 C.

Sderstrm, T.; Haug, F.-J.; Niquille, X.; Terrazzoni, V.; Ballif, C.

2009-02-01

255

Light confinement in e-beam evaporated thin film polycrystalline silicon solar cells  

Energy Technology Data Exchange (ETDEWEB)

Polycrystalline Si thin-film (poly-Si) solar cells need effective light-trapping to compensate for the moderate absorption. Recent developments in the poly-Si cell technology focus on film fabrication by e-beam evaporation due to its manufacturing benefits, such as a very high deposition rate above 15 nm/s and inline compatible process. However, evaporated poly-Si cells exhibit limited compatibility with textured glass. In this Letter, the coupling of the light in the absorber layer is enhanced by introducing a rough interface at the back of the solar cells. This increases the conversion efficiency from 6% to 7.1% for, respectively, planar and back textured interface with current density of 26.6 mA/cm{sup 2} for only 3.6 {mu}m absorber thickness. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Soderstrom, T.; Wang, Q.; Omaki, K.; Varlamov, S. [ARC Photovoltaics Centre of Excellence, UNSW, Sydney NSW 2052 (Australia); Kunz, O.; Ong, D. [CSG Solar Pty Ltd, 82 Bay Street, Botany NSW 2019 (Australia)

2011-06-15

256

Effect of Gaussian doping profile on the performance of a thin film polycrystalline solar cell  

Directory of Open Access Journals (Sweden)

Full Text Available A two-dimensional (2D) analytical model based on the Greens function method is applied to an n+-p thin film polycrystalline solar cell that allows us to calculate the conversion efficiency. This model considers the effective Gaussian doping profile in the p region in order to improve cell efficiency. The dependence of mobility and lifetime on grain doping is also investigated. This model is implemented through a simulation program in order to optimize conversion efficiency while varying thickness and doping profile in the base region of the cell. Compared with n+-p standard structure, our proposed structure shows a 43% improvement in conversion efficiency for a polycrystalline solar cell.

Kolsi S.; Ben Amar M.; Samet H.; Ouali A.

2012-01-01

257

Thin film solar cell and its production method; Hakumaku taiyo denchi oyobi sono seizo hoho  

Energy Technology Data Exchange (ETDEWEB)

The production cost of conventional solar cell is high because it needs surface-sealing glass for protecting the cell from rain, dust, or shock in order to have a durability of more than 20 years. This invention solves the problem. The invented super-straight type thin film solar cell is produced in the following way: The CdS film is laminated on the SnO2 electrode which is set on the substrate by means of solution method or sputtering method. Then the thin film of CuIn(x)Ga(1-x)Se(y)S(2-y), (0 {le} x < 1 and 0 < y {le} 2) system is formed on the CdS film. Putting the SnO2 electrode on the substrate can eliminate the expensive glass. Instead an ordinary sealant film or moisture-proof resin can be satisfactorily used. In addition, this structure makes it possible to use glass substrate with commonly-used transparent electrode. Also, the laser patterning technique can be used for the modulation. So that the process control can be done easily and inexpensively. 4 figs.

Kondo, K. [Tokyo (Japan); Sano, H. [Saitama (Japan); Nakamura, S. [Yokohama (Japan)

1996-06-21

258

Organic-thin-film-coated solar cells: energy transfer between surface pyrene molecules and the silicon semiconductor substrate  

Energy Technology Data Exchange (ETDEWEB)

The energy-transfer processes in a pyrene thin film, deposited onto a silicon solar cell, are investigated. An increase in the solar-cell efficiency is observed for cells coated with a pyrene thin film. The increase in efficiency is attributed to a combination of two effects: (i) the antireflective properties of the pyrene film and (ii) direct energy transfer from pyrene to silicon. A comparison of emission, photoexcitation, and spectral response data reveals the nature of the pyrene energy transfer to be radiative.

McCaffrey, Robert R.; Prasad, Paras N.

1984-01-01

259

Light Trapping in Thin Film Silicon Solar Cells on Plastic Substrates  

Science.gov (United States)

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 130-140C. At 130C 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%.

de Jong, M. M.

2013-01-01

260

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

 
 
 
 
261

Polycrystalline thin-film CuInSe/sub 2//CdZnS solar cells  

Energy Technology Data Exchange (ETDEWEB)

The fabrication and properties of polycrystalline, CuInSe/sub 2/ thin-film solar cells based upon a heterojunction device structure of P-type CuInSe/sub 2/ and N-type CdS or mixed CdZnS are described. A photovoltaic conversion efficiency of 11 percent is reported for a CuInSe/sub 2// CdZnS cell of 1-cm/sup 2/ area when tested under simulated AM1 illumination (ELH lamp). While the highest efficiency cells have been prepared on Mo-metallized, polycrystalline alumina substrates, good cell performance is also presented for cells fabricated on low-cost glass substrates. The vacuum deposited selenide and sulfide films are reported to exhibit strong columnar growth features throughout the critical junction region. The spectral response of the cells is described as being relatively flat from 1100 to 600 nm with very high quantum yields (> 0.8). Photoluminescence emission data on the CuInSe/sub 2/ thin-film excited with a He-Ne laser is presented. In general, selenide films producing a good cell performance are reported to exhibit spectra with two or three major broad-band emissions.

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

1984-05-01

262

First principles study of Bi dopen CdTe thin film solar cells: electronic and optical properties  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Nowadays, efficiency improvement of solar cells is one of the most important issues in photovoltaic systems and CdTe is one of the most promising thin film photovoltaic materials we can found. CdTe reported efficiencies in solar energy conversion have been as good as that found in polycrystalline Si...

Seminvski Prez, Yohanna; Palacios Clemente, Pablo; Wahnn Benarroch, Perla

263

Embedded biomimetic nanostructures for enhanced optical absorption in thin-film solar cells.  

UK PubMed Central (United Kingdom)

Light-management is critical to thin film solar cells due to their usually limited optical absorption in the active layer. Conventional approaches involve employing separate techniques for anti-reflection and light trapping. Here, we demonstrate an embedded biomimetic nanostructure (EBN) that achieves both effects for hydrogenated amorphous silicon (a-Si:H) solar cells. The fabrication of EBNs is accomplished by patterning an index-matching silicon-nitride layer deposited on a glass substrate using polystyrene nanospheres lithography, followed by reactive ion etching. The profile of EBN is then reproduced layer by layer during the deposition of a-Si:H cells. We show that a solar cell with an optimized EBN exhibits a broadband enhanced external quantum efficiency due to both anti-reflection and light-trapping, with respect to an industrial standard cell using an Asahi U glass substrate which is mostly optimized for light trapping. Overall, the cell with an optimized EBN achieves a large short-circuit current density of 17.74 mA/cm(2), corresponding to a 37.63% enhancement over a flat control cell. The power conversion efficiency is also increased from 5.36% to 8.32%. Moreover, the light management enabled by the EBN remains efficient over a wide range of incident angles up to 60, which is particularly desirable for real environments with diffused sun light. The novel patterning method is not restricted to a-Si:H solar cells, but is also widely applicable to other thin film materials.

Tsai MA; Han HW; Tsai YL; Tseng PC; Yu P; Kuo HC; Shen CH; Shieh JM; Lin SH

2011-07-01

264

Simulation of a-Si/a-SiGe thin film tandem junction solar cells  

International Nuclear Information System (INIS)

Amorphous silicon (a-Si) based thin film tandem junction solar cells are simulated based on a uniform field collection model. From the photovoltaic parameters of a single junction a-Si top cell and a few amorphous silicon-germanium (a-SiGe) bottom cells, the optimized a-Si/a-SiGe tandem cell can be predicted. The simulation results are in good agreement with the experiment. The highest efficiency a-Si/a-SiGe tandem cells are obtained with a combination of a-SiGe characteristics and a relatively large mismatch in the short circuit current between the top and bottom cells. A key reason for this behaviour is that the tandem cell may exhibit a larger fill factor than either one of the component cells under a certain current mismatch.

2010-04-14

265

Fabrication of thin film nanocrystalline silicon solar cell with low light-induced degradation  

Energy Technology Data Exchange (ETDEWEB)

Nanocrystalline silicon thin films have been deposited at different total gas flow rates and plasma excitation frequencies and samples with similar crystalline volume fraction have been compared. In hydrogenated nanocrystalline silicon solar cells, amorphous component is not necessarily the only determining factor for light-induced degradation. Smaller grain size less than 3 nm diameter and intermediate range order provide a better stability in the i-layer near the p/i interface, thus improving the overall stability of the solar cell. Light-induced degradation (LID) of efficiency of the cell mainly depends on the light-induced degradation of short-circuit current density and light-induced degradation of fill factor (FF). Degradation of open-circuit voltage is less than 1%. Minimum degradation of efficiency obtained in this work is 2%. (author)

Chowdhury, Amartya; Mukhopadhyay, Sumita; Ray, Swati [Energy Research Unit, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032 (India)

2009-05-15

266

High efficiency thin film solar cells grown by molecular beam epitaxy (HEFTY)  

Energy Technology Data Exchange (ETDEWEB)

The project sought to show the UK as a world leader in the field of thin film crystalline solar cells. A premise was that the cell design be suitable for large-scale manufacturing and provide a basis for industrial exploitation. The study demonstrated (1) that silicon films grown at temperatures suitable for deposition on glass by Gas Phase Molecular Beam Epitaxy gives better PV cells than does Ultra Low Pressure Chemical Vapor Deposition; (2) a conversion energy of 15 per cent was achieved - the project target was 18 per cent and (3) one of the highest reported conversion efficiencies for a 15 micrometre silicon film was achieved. The study was carried out by BP Solar Limited under contract to the DTI.

Mason, N.B.; Barnham, K.W.J.; Ballard, I.M.; Zhang, J. [Imperial College, London (United Kingdom)

2006-05-04

267

Optimizing two-level hierarchical particles for thin-film solar cells.  

Science.gov (United States)

For the thin-film solar cells embedded with nanostructures at their rear dielectric layer, the shape and location of the nanostructures are crucial for higher conversion efficiency. A novel two-level hierarchical nanostructure (a sphere evenly covered with half truncated smaller spheres) can facilitate stronger intensity and wider scattering angles due to the coexistence of the merits of the nanospheres in two scales. We show in this article that the evolutionary algorithm allows for obtaining the optimal parameters of this two-scale nanostructure in terms of the maximization of the short circuit current density. In comparison with the thin-film solar cells with convex and flat metal back, whose parameters are optimized singly, the short circuit current density is improved by 7.48% and 10.23%, respectively. The exploration of such a two-level hierarchical nanostructure within an optimization framework signifies a new domain of study and allows to better identify the role of sophisticated shape in light trapping in the absorbing film, which is believed to be the main reason for the enhancement of short circuit current density. PMID:23482291

Zhou, Shiwei; Hunang, Xiaodong; Li, Qing; Xie, Yi Min

2013-03-11

268

Optimizing two-level hierarchical particles for thin-film solar cells.  

UK PubMed Central (United Kingdom)

For the thin-film solar cells embedded with nanostructures at their rear dielectric layer, the shape and location of the nanostructures are crucial for higher conversion efficiency. A novel two-level hierarchical nanostructure (a sphere evenly covered with half truncated smaller spheres) can facilitate stronger intensity and wider scattering angles due to the coexistence of the merits of the nanospheres in two scales. We show in this article that the evolutionary algorithm allows for obtaining the optimal parameters of this two-scale nanostructure in terms of the maximization of the short circuit current density. In comparison with the thin-film solar cells with convex and flat metal back, whose parameters are optimized singly, the short circuit current density is improved by 7.48% and 10.23%, respectively. The exploration of such a two-level hierarchical nanostructure within an optimization framework signifies a new domain of study and allows to better identify the role of sophisticated shape in light trapping in the absorbing film, which is believed to be the main reason for the enhancement of short circuit current density.

Zhou S; Hunang X; Li Q; Xie YM

2013-03-01

269

Annealing enhancement effect by light illumination on proton irradiated Cu(In, Ga)Se{sub 2} thin-film solar cells  

Energy Technology Data Exchange (ETDEWEB)

In this paper, we investigated the high radiation tolerance of copper indium gallium di-selenide (CIGS) thin-film solar cells by conducting in situ measurements of short circuit current and open circuit voltage of CIGS thin-film solar cells during and after proton irradiation under short circuit condition. We found that the annealing rate of proton-induced defects in CIGS thin-film solar cells under light illumination with an AM0 solar simulator is higher than that under dark conditions. The activation energy of proton-induced defects in the CIGS thin-film solar cells with (without) light illumination is 0.80 eV (0.92 eV), which implies on enhanced defect annealing rate in CIGS thin-film solar cells due to minority-carrier injection. (author)

Kawakita, Shirou; Imaizumi, Mitsuru; Matsuda, Sumio [National Space Development Agency of Japan, Tsukuba, Ibaraki (Japan); Yamaguchi, Masafumi [Toyota Technological Institute, Nagoya, Aichi (Japan); Kushiya, Katsumi [Showa Shell Sekiyu K.K, Central R and D Laboratory (ARL), Atsugi, Kanagawa (Japan); Ohshima, Takeshi; Itoh, Hisayoshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

2002-07-01

270

Highly efficient hybrid thin-film solar cells using a solution-processed hole-blocking layer.  

Science.gov (United States)

We report the origin of the improvement of the power conversion efficiency (PCE) of hybrid thin-film solar cells when a soluble C(60) derivative, [6,6]-phenyl-C(61)-butyric acid methyl ester (PCBM), is introduced as a hole-blocking layer. The PCBM layer could establish better interfacial contact by decreasing the reverse dark-saturation current density, resulting in a decrease in the probability of carrier recombination. The PCE of this optimized device reached a maximum value of 8.34% and is the highest yet reported for hybrid thin-film solar cells. PMID:23258449

Seo, Ji Hoon; Kim, Dong-Ho; Kwon, Se-Hun; Park, Yun Chang; Jung, Hyung Hwan; Lee, Hyung Woo; Kwon, Jung-Dae; Park, Sung-Gyu; Nam, Kee-Seok; Jeong, Yongsoo; Ryu, Seung Yoon; Kang, Jae-Wook; Kim, Chang Su

2012-12-21

271

Highly efficient hybrid thin-film solar cells using a solution-processed hole-blocking layer.  

UK PubMed Central (United Kingdom)

We report the origin of the improvement of the power conversion efficiency (PCE) of hybrid thin-film solar cells when a soluble C(60) derivative, [6,6]-phenyl-C(61)-butyric acid methyl ester (PCBM), is introduced as a hole-blocking layer. The PCBM layer could establish better interfacial contact by decreasing the reverse dark-saturation current density, resulting in a decrease in the probability of carrier recombination. The PCE of this optimized device reached a maximum value of 8.34% and is the highest yet reported for hybrid thin-film solar cells.

Seo JH; Kim DH; Kwon SH; Park YC; Jung HH; Lee HW; Kwon JD; Park SG; Nam KS; Jeong Y; Ryu SY; Kang JW; Kim CS

2013-02-01

272

Thin film solar cells with Si nanocrystallites embedded in amorphous intrinsic layers by hot-wire chemical vapor deposition.  

Science.gov (United States)

We investigated the thin film growths of hydrogenated silicon by hot-wire chemical vapor deposition with different flow rates of SiH4 and H2 mixture ambient and fabricated thin film solar cells by implementing the intrinsic layers to SiC/Si heterojunction p-i-n structures. The film samples showed the different infrared absorption spectra of 2,000 and 2,100 cm(-1), which are corresponding to the chemical bonds of SiH and SiH2, respectively. The a-Si:H sample with the relatively high silane concentration provides the absorption peak of SiH bond, but the microc-Si:H sample with the relatively low silane concentration provides the absorption peak of SiH2 bond as well as SiH bond. Furthermore, the microc-Si:H sample showed the Raman spectral shift of 520 cm(-1) for crystalline phase Si bonds as well as the 480 cm(-1) for the amorphous phase Si bonds. These bonding structures are very consistent with the further analysis of the long-wavelength photoconduction tail and the formation of nanocrystalline Si structures. The microc-Si:H thin film solar cell has the photovoltaic behavior of open circuit voltage similar to crystalline silicon thin film solar cell, indicating that microc-Si:H thin film with the mixed phase of amorphous and nanocrystalline structures show the carrier transportation through the channel of nanocrystallites. PMID:23858866

Park, Seungil; Parida, Bhaskar; Kim, Keunjoo

2013-05-01

273

Thin film solar cells with Si nanocrystallites embedded in amorphous intrinsic layers by hot-wire chemical vapor deposition.  

UK PubMed Central (United Kingdom)

We investigated the thin film growths of hydrogenated silicon by hot-wire chemical vapor deposition with different flow rates of SiH4 and H2 mixture ambient and fabricated thin film solar cells by implementing the intrinsic layers to SiC/Si heterojunction p-i-n structures. The film samples showed the different infrared absorption spectra of 2,000 and 2,100 cm(-1), which are corresponding to the chemical bonds of SiH and SiH2, respectively. The a-Si:H sample with the relatively high silane concentration provides the absorption peak of SiH bond, but the microc-Si:H sample with the relatively low silane concentration provides the absorption peak of SiH2 bond as well as SiH bond. Furthermore, the microc-Si:H sample showed the Raman spectral shift of 520 cm(-1) for crystalline phase Si bonds as well as the 480 cm(-1) for the amorphous phase Si bonds. These bonding structures are very consistent with the further analysis of the long-wavelength photoconduction tail and the formation of nanocrystalline Si structures. The microc-Si:H thin film solar cell has the photovoltaic behavior of open circuit voltage similar to crystalline silicon thin film solar cell, indicating that microc-Si:H thin film with the mixed phase of amorphous and nanocrystalline structures show the carrier transportation through the channel of nanocrystallites.

Park S; Parida B; Kim K

2013-05-01

274

X-ray fluorescence measurements of thin film chalcopyrite solar cells  

Energy Technology Data Exchange (ETDEWEB)

X-ray fluorescence has turned out to be a very suitable and reliable tool for the characterization of thin film chalcopyrite solar cells. Besides the composition determination in atomic percent the total mass per unit square (mg/cm{sup 2}) of the analyzed elements and the film thickness can be measured accurately. Furthermore, a real multi-layer analysis allows in addition to determine the CdS, ZnO and Mo thickness simultaneously with the absorber measurement. By the use of etching techniques, information about a vertical composition gradient can also be obtained. This work shows the possibilities and limitations of the X-ray fluorescence technique for the chalcopyrite solar cell characterization and emphasizes the advantages over the widespread electron probe microanalysis

Klenk, M.; Schenker, O.; Probst, U.; Bucher, E. [Universitaet Konstanz, Fakultaet fuer Physik, P.O. Box X 916, D-78457 Konstanz (Germany)

1999-07-15

275

A novel route to a polycrystalline silicon thin-film solar cell  

Energy Technology Data Exchange (ETDEWEB)

An alternative approach is described for the fabrication of a polycrystalline silicon thin-film solar cell on inexpensive substrates. In a first step amorphous silicon is recrystallized in an aluminum-induced crystallization process forming a large-grained polycrystalline silicon layer on glass or metal substrates. In a second step this layer is used as a template for epitaxial growth of the absorber layer (2-3 {mu}m thick) at T<600 {sup o}C using ion-assisted deposition techniques. The third step consists of the formation of an a-Si:H/c-Si heterojunction by depositing an a-Si:H emitter from the gas phase. It will be shown that each of these steps has been successfully developed and can now be implemented in a solar cell process. (author)

Fuhs, W.; Gall, S.; Rau, B.; Schmidt, M.; Schneider, J. [Hahn-Meitner Institut Berlin (Germany). Abt. Silizium-Photovoltaik

2004-12-01

276

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

Directory of Open Access Journals (Sweden)

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.

R. B. Bergmann; T. J. Rinke; R. M. Hausner; M. Grauvogl; M. Vetter; J. H. Werner

1999-01-01

277

Electron-reflector strategy for cadmium telluride thin-film solar cells  

Science.gov (United States)

The CdTe thin-film solar cell has a large absorption coefficient and high theoretical efficiency. Moreover, large-area photovoltaic panels can be economically fabricated. These features potentially make the CdTe thin-film solar cell the leading alternative energy source. However, the record CdTe efficiency (16.5%) is much less than its theoretical maximum efficiency (29%), primarily because the open-circuit voltage (0.845 V) is well below what is expected for its band gap (1.5 eV). The incorporation of an electron reflector is a strategy to improve the open-circuit voltage of solar cells, and thus a strong possibility to improve the efficiency of CdTe thin-film solar cells. An electron reflector is a conduction-band energy barrier at the back surface of the solar cell, which can reduce the recombination due to the electron flow to the back surface. Different methods to create an electron reflector are explained in the thesis: (1) expanded band gap, either an expanded-band-gap layer or a bulk-band-gap reduction, and (2) alteration to the band bending through a reversed back barrier or a heavily-doped back surface. Investigation shows that the expanded-band-gap layer is the most efficient and practical mechanism for an electron reflector, and the combination of any two mechanisms does not yield additional improvement. To have the optimal effect from the electron-reflector strategy, reasonable CdTe lifetime (1 ns or above) and full depletion of the CdTe layer are required to ensure high carrier collection. Furthermore, a good-quality reflector interface between the p-type CdTe layer and the electron-reflector layer is essential. Preliminary experimental evidence has shown that CdTe cells with a ZnTe back layer do have a slightly higher open-circuit voltage. An electron reflector should be particularly beneficial for thin (less than 2 microm) CdTe cells which have a fully-depleted CdTe absorber layer. Thin CdTe cells can also benefit from the optical reflection at the back surface. To investigate the possibility of still higher efficiency, both electron and optical reflection were numerically applied to the CdTe record-cell baseline model. However, there is little improvement for CdTe thicknesses greater than 2 microm. To have the optimal effect from combined electron and optical reflection, cells approximately one micron thick are required. Even without the improvement to the current quality of CdTe, cell efficiency above 19% should be achievable with a 0.2-eV electron reflector. Moreover, efficiency above 20% should be possible if one can also achieve large optical back reflection. At the same time, competitive CdTe cell performance at a thickness as thin as 0.4 um should be possible. This thesis gives a comprehensive numerical investigation of the electron-reflector strategy for CdTe thin-film solar cells.

Hsiao, Kuo-Jui

278

Modelling and Degradation Characteristics of Thin-film CIGS Solar Cells  

Energy Technology Data Exchange (ETDEWEB)

Thin-film solar cells based around the absorber material CuIn{sub 1-x}Ga{sub x}Se2 (CIGS) are studied with respect to their stability characteristics, and different ways of modelling device operation are investigated. Two ways of modelling spatial inhomogeneities are detailed, one fully numerical and one hybrid model. In the numerical model, thin-film solar cells with randomized parameter variations are simulated showing how the voltage decreases with increasing material inhomogeneities. With the hybrid model, an analytical model for the p-n junction action is used as a boundary condition to a numerical model of the steady state electrical conduction in the front contact layers. This also allows for input of inhomogeneous material parameters, but on a macroscopic scale. The simpler approach, compared to the numerical model, enables simulations of complete cells. Effects of material inhomogeneities, shunt defects and grid geometry are simulated. The stability of CIGS solar cells with varying absorber thickness, varying buffer layer material and CIGS from two different deposition systems are subjected to damp heat treatment. During this accelerated ageing test the cells are monitored using characterization methods including J-V, QE, C-V and J(V)T. The degradation studies show that the typical VOC decrease experienced by CIGS cells subjected to damp heat is most likely an effect in the bulk of the absorber material. When cells encapsulated with EVA are subjected to the same damp heat treatment, the effect on the voltage is considerably reduced. In this situation the EVA is saturated with moisture, representing a worst case scenario for a module in operation. Consequently, real-life modules will not suffer extensively from the VOC degradation effect, common in unprotected CIGS devices

Palm, Ulf

2008-10-15

279

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

Directory of Open Access Journals (Sweden)

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.

Birlo M.; Differt D.; Lkermann F.; Pfeiffer W.; Stiebig H.

2013-01-01

280

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

Directory of Open Access Journals (Sweden)

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, making 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 m). 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 m, 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.

J. Sastr-Hernndez; M.E. Calixto; M. Tufio-Velzquez; G. Contreras-Puente; A. Morales-Acevedo; G. Casados-Cruz; M.A. Hernndez-Prez; M.L. Albor-Aguilera; R. Mendoza-Prez

2011-01-01

 
 
 
 
281

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

Scientific Electronic Library Online (English)

Full Text Available Abstract in english 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, making 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) s (more) ubstrates. 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 m). 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 m, 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.

Sastr-Hernndez, J.; Calixto, M.E.; Tufio-Velzquez, M.; Contreras-Puente, G.; Morales-Acevedo, A.; Casados-Cruz, G.; Hernndez-Prez, M.A.; Albor-Aguilera, M.L.; Mendoza-Prez, R.

2011-10-01

282

Electrical impact of MoSe2 on CIGS thin-film solar cells.  

UK PubMed Central (United Kingdom)

The CIGS solar cell is one of the most promising photovoltaic devices due to the achievement of the highest conversion efficiency (>20%) among all thin-film solar cells. The CIGS cell has a glass/Mo/CIGS/CdS/TCO configuration, and the CIGS-Mo interface is a Schottky barrier to holes. During the sulfurization-after-selenization (SAS) CIGS formation process with H2Se gas, the Mo surface transforms naturally into MoSe2 at the CIGS-Mo interface. In this work, the electrical impact of MoSe2 on CIGS solar cells was investigated. Different CIGS-Mo interfaces were prepared with two CIGS processes. One is SAS, and the other is the sequential-sputtering-selenization CIGS process with Se gas. Formation of MoSe2 is hardly observed in the latter process. Samples were characterized by XRD, the van der Pauw method, reflectance, and visual inspection. Besides, Schottky barrier heights of cells were extracted from J-V-T measurements. For the first time, it was experimentally shown that the existence of thin MoSe2 film can decrease the apparent Schottky barrier height of CIGS solar cells. In addition, 1-dimensional numerical simulation showed that a larger barrier height affects both the fill factor and open-circuit voltage. Therefore, the formation of MoSe2 during the CIGS process should minimize the negative effect of Schottky barrier on solar-cell performances, especially with large Schottky barrier.

Hsiao KJ; Liu JD; Hsieh HH; Jiang TS

2013-10-01

283

Electrical impact of MoSe2 on CIGS thin-film solar cells.  

UK PubMed Central (United Kingdom)

The CIGS solar cell is one of the most promising photovoltaic devices due to the achievement of the highest conversion efficiency (>20%) among all thin-film solar cells. The CIGS cell has a glass/Mo/CIGS/CdS/TCO configuration, and the CIGS-Mo interface is a Schottky barrier to holes. During the sulfurization-after-selenization (SAS) CIGS formation process with H2Se gas, the Mo surface transforms naturally into MoSe2 at the CIGS-Mo interface. In this work, the electrical impact of MoSe2 on CIGS solar cells was investigated. Different CIGS-Mo interfaces were prepared with two CIGS processes. One is SAS, and the other is the sequential-sputtering-selenization CIGS process with Se gas. Formation of MoSe2 is hardly observed in the latter process. Samples were characterized by XRD, the van der Pauw method, reflectance, and visual inspection. Besides, Schottky barrier heights of cells were extracted from J-V-T measurements. For the first time, it was experimentally shown that the existence of thin MoSe2 film can decrease the apparent Schottky barrier height of CIGS solar cells. In addition, 1-dimensional numerical simulation showed that a larger barrier height affects both the fill factor and open-circuit voltage. Therefore, the formation of MoSe2 during the CIGS process should minimize the negative effect of Schottky barrier on solar-cell performances, especially with large Schottky barrier.

Hsiao KJ; Liu JD; Hsieh HH; Jiang TS

2013-09-01

284

Very thin film crystalline silicon solar cells on glass substrate fabricated at low temperature  

Energy Technology Data Exchange (ETDEWEB)

The performances of thin-film poly-Si solar cells with a thickness of less than 5 {micro}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 depositing (CVD) at low temperature. The cell with a thickness of 2.0 {micro}m demonstrated an intrinsic efficiency of 10.7% (aperture 10.1%), the open-circuit voltage of 0.539 V and the short current density of 25.8 mA/cm{sub 2} as independently confirmed by Japan Quality Assurance, which shows the no clear light-induced degradation. The optical and transport properties of poly-Si cells are summarized.

Yamamoto, Kenji

1999-10-01

285

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.

2006-07-26

286

Effects of the production, use and disposal of thin film solar cells and modules on environment and health. Status report; Umwelt- und Gesundheitsauswirkungen der Herstellung und Anwendung sowie Entsorgung von Duennschichtsolarzellen und Modulen. Kenntnisstandbericht  

Energy Technology Data Exchange (ETDEWEB)

The following subjects were investigated in the framework of this research report: Basic materials for thin film solar cells; Production of thin film solar cells; Uses and performance of thin film solar cells; Disposal of thin film solar cells. (HW) [Deutsch] Im Rahmen des vorliegenden Forschungsberichtes werden folgende Schwerpunkte untersucht: - Ausgangsmaterialien fuer Duennschichtzellen - Herstellung von Duennschichtzellen - Einsatz und Betrieb von Duennschichtzellen - Entsorgung von Duennschichtzellen. (HW)

Steinberger, H.

1995-12-31

287

Peel-and-Stick: Fabricating Thin Film Solar Cell on Universal Substrates  

Science.gov (United States)

Fabrication of thin-film solar cells (TFSCs) on substrates other than Si and glass has been challenging because these nonconventional substrates are not suitable for the current TFSC fabrication processes due to poor surface flatness and low tolerance to high temperature and chemical processing. Here, we report a new peel-and-stick process that circumvents these fabrication challenges by peeling off the fully fabricated TFSCs from the original Si wafer and attaching TFSCs to virtually any substrates regardless of materials, flatness and rigidness. With the peel-and-stick process, we integrated hydrogenated amorphous silicon (a-Si:H) TFSCs on paper, plastics, cell phone and building windows while maintaining the original 7.5% efficiency. The new peel-and-stick process enables further reduction of the cost and weight for TFSCs and endows TFSCs with flexibility and attachability for broader application areas. We believe that the peel-and-stick process can be applied to thin film electronics as well.

Lee, Chi Hwan; Kim, Dong Rip; Cho, In Sun; William, Nemeth; Wang, Qi; Zheng, Xiaolin

2012-01-01

288

Peel-and-stick: fabricating thin film solar cell on universal substrates.  

UK PubMed Central (United Kingdom)

Fabrication of thin-film solar cells (TFSCs) on substrates other than Si and glass has been challenging because these nonconventional substrates are not suitable for the current TFSC fabrication processes due to poor surface flatness and low tolerance to high temperature and chemical processing. Here, we report a new peel-and-stick process that circumvents these fabrication challenges by peeling off the fully fabricated TFSCs from the original Si wafer and attaching TFSCs to virtually any substrates regardless of materials, flatness and rigidness. With the peel-and-stick process, we integrated hydrogenated amorphous silicon (a-Si:H) TFSCs on paper, plastics, cell phone and building windows while maintaining the original 7.5% efficiency. The new peel-and-stick process enables further reduction of the cost and weight for TFSCs and endows TFSCs with flexibility and attachability for broader application areas. We believe that the peel-and-stick process can be applied to thin film electronics as well.

Lee CH; Kim DR; Cho IS; William N; Wang Q; Zheng X

2012-01-01

289

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

Science.gov (United States)

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.

Ray, Abhijit; Patel, Malkeshkumar; Tripathi, Brijesh; Kumar, Manoj

2012-06-01

290

Thin film polycrystalline silicon solar cells: first technical progress report, April 15, 1980-July 15, 1980  

Energy Technology Data Exchange (ETDEWEB)

The objectives of this contract are to fabricate large area thin film silicon solar cells with AM1 efficiency of 10% or greater with good reproducibility and good yield and to assess the feasibility of implementing this process for manufacturing solar cells at a cost of $300/kWe. Efforts during the past quarter have been directed to the purification of metallurgical silicon, the preparation of substrates, and the fabrication and characterization of solar cells. The partial purification of metallurgical silicon by extraction with aqua regia has been investigated in detail, and the resulting silicon was analyzed by the atomic absorption technique. The unidirectional solidification of aqua regia-extracted metallurgical silicon on graphite was used for the preparation of substrates, and the impurity distribution in the substrate was also determined. Large area (> 30 cm/sup 2/) solar cells have been prepared from aqua regia-extracted metallurgical silicon substrates by the thermal reduction of trichlorosilane containing appropriate dopants. Chemically deposited tin-dioxide films were used as antireflection coatings. Solar cells with AM1 efficiencies of about 8.5% have been obtained. Their spectral response, minority carrier diffusion length, and I/sub sc/-V/sub oc/ relation have been measured.

None

1980-07-01

291

Solar cells with improved efficiency based on electrodeposited copper indium diselenide thin films. [CuInSe[sub 2  

Energy Technology Data Exchange (ETDEWEB)

Solar cells based on CuInSe[sub 2] (CIS) thin films prepared as described in the previous contribution have been prepared and characterized. The light and dark current-voltage curves and spectral responses are presented, showing that annealing in a selenium atmosphere makes it possible to fabricate ZnO/CdS/CIS solar cells with improved efficiencies. CIS is of particular interest because its optical properties are well matched to the solar spectrum. (orig.)

Guillemoles, J.F. (Ecole Nationale Superieure de Chimie, 75 - Paris (France). Lab. d' Electrochimie Analytique et Appliquee); Cowache, P. (Ecole Nationale Superieure de Chimie, 75 - Paris (France). Lab. d' Electrochimie Analytique et Appliquee); Massaccesi, S. (Ecole Nationale Superieure de Chimie, 75 - Paris (France). Lab. d' Electrochimie Analytique et Appliquee); Thouin, L. (Ecole Nationale Superieure de Chimie, 75 - Paris (France). Lab. d' Electrochimie Analytique et Appliquee); Sanchez, S. (Ecole Nationale Superieure de Chimie, 75 - Paris (France). Lab. d' Electrochimie Analytique et Appliquee); Lincot, D. (Ecole Nationale Superieure de Chimie, 75 - Paris (France). Lab. d' Electrochimie Analytique et Appliquee); Vedel, J. (Ecole Nationale Superieure de Chimie, 75 - Paris (France). Lab. d' Electrochimie Analytique et Appliquee)

1994-05-01

292

Surface textured molybdenum doped zinc oxide thin films prepared for thin film solar cells using pulsed direct current magnetron sputtering  

International Nuclear Information System (INIS)

In this study, we examined the effect of etching on the electrical properties, transmittance, and scattering of visible light in molybdenum doped zinc oxide, ZnO:Mo (MZO) thin films prepared by pulsed direct current magnetron sputtering. We used two different etching solutions - KOH and HCl - to alter the surface texture of the MZO thin film so that it could trap light. The experimental results showed that an MZO film with a minimum resistivity of about 8.9 x 10-4 ? cm and visible light transitivity of greater than 80% can be obtained without heating at a Mo content of 1.77 wt.%, sputtering power of 100 W, working pressure of 0.4 Pa, pulsed frequency of 10 kHz, and film thickness of 500 nm. To consider the effect of resistivity and optical diffuse transmittance, we performed etching of an 800 nm thick MZO thin film with 0.5 wt.% HCl for 3-6 s at 300 K. Consequently, we obtained a resistivity of 1.74-2.75 x 10-3 ? cm, total transmittance at visible light of 67%-73%, diffuse transmittance at visible light of 25.1%-28.4%, haze value of 0.34-0.42, and thin film surface crater diameters of 220-350 nm.

2011-06-01

293

Nanosize copper encapsulated carbon thin films on a dye-sensitized solar cell cathode.  

UK PubMed Central (United Kingdom)

Deposition of the nanosize copper encapsulated carbon (Cu@C) thin film onto the cathode has been studied to enhance efficiency of the dye-sensitized solar cell (DSSC). The X-ray diffraction (XRD) patterns of the Cu@C are suggestive of existence of metallic copper (Cu) nanoparticles in the thin film. The UV-visible spectrum of the Cu@C coated on indium-doped tin oxide (ITO) shows a red shift (probably due to the longitudinal resonance) as the size of Cu in the Cu@C increases. Moreover, the images observed by field-emission scanning electron microscopy (FE-SEM) indicate that the Cu@C nanoparticles are well dispersed on ITO. By extended X-ray absorption fine structure (EXAFS) spectroscopy, a decrease of the coordination number (CN) of Cu-Cu with decreasing sizes of Cu in the Cu@C is observed. Interestingly, an enhanced efficiency of the DSSC with the Cu@C nanoparticles coated ITO cathode by 50% is found if compared with the relatively expensive Pt electrode. As the size of Cu in the Cu@C on ITO decreases (e.g., 20 --> 7 nm), the efficiency of the DSSC can be increased by 80% approximately.

Huang CH; Wang HP; Liao CY

2010-07-01

294

Production method of thin film solar cell; Hakumaku taiyo denchi no seizo hoho  

Energy Technology Data Exchange (ETDEWEB)

The invented production method of thin film solar cell is as follows: The semiconductor thin film having the electrode layers on its both side is laminated to one side of the insulator substrate. The substrate is then cut together with the laminated layer using a cutting tool. A preferable way of production is employing the glass substrate as the insulator substrate and employing the glass cutter as the cutting tool to cut the substrate together with the laminated layer. An alternative way is employing a flexible substrate as the insulator substrate and employing a circular punching tool to make holes through the substrate and the laminated layer or employing an ultrasonic cutter as the cutting tool to cut the substrate and the laminated layer. These ways of production give a force which expands outward the both side of the laminated layer during the cutting or punching process. So that the sagging of the electrode in the fabrication direction can be prevented. No short-circuiting takes place between the electrodes since no heat is applied unlike the laser processing. 5 figs.

Saito, S.

1996-05-07

295

Electrical Properties of Al, Ag, Cu, Ti and SS Thin Film for Electrode of Solar Cell  

International Nuclear Information System (INIS)

[en]The Al, Ag, Cu, Ti and SS materials were deposited on the surface of glass substrate using plasma DC sputtering technique. The deposition process was done with the following plasma parameters : deposition time, gas pressure and substrate temperature with the aim to obtain a good conductance of thin films. Variation of substrate deposition time was 1 - 15 minutes, gas pressure was 5x10-2 - 7x10-2 torr and of temperature was 100 - 300 oC. The resistance measurement has been done by four points probes and the conductivity was calculated using mathematic formulation. It was obtained that the minimum resistance in the order of R = 0.07 ?, was found at Ag materials and this was obtained at the following plasma parameters : deposition time 15 minutes, gas pressure 6x10-2 torr and temperature 300 oC, while, the resistance of : Cu, Al, Ti and SS materials were R = 0.13 ?, R = 450 ?, R = 633 ?, R = 911 ? respectively, It could be concluded that the Ag thin film has a minimum resistance, high conductivity compared to the other materials Al, Cu, Ti and SS. Ag is therefore the suitable material for applying as electrode of solar cell. (author)

2003-10-01

296

Single source precursors for fabrication of I-III-VI2 thin-film solar cells via spray CVD  

International Nuclear Information System (INIS)

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). Thin-film fabrication studies demonstrate that ternary single source precursors can be used in either a hot, or cold-wall spray chemical vapour deposition reactor, for depositing CuInS2, CuGaS2 and CuGaInS2 at reduced temperatures (400-450 sign C), which display good electrical and optical properties suitable for photovoltaic devices. X-ray diffraction studies, energy dispersive spectroscopy and scanning electron microscopy confirmed the formation of the single phase CIS, CGS, CIGS thin-films on various substrates at reduced temperatures.

2003-05-01

297

Overview and Challenges of Thin Film Solar Electric Technologies  

Energy Technology Data Exchange (ETDEWEB)

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.

Ullal, H. S.

2008-12-01

298

Effects of deposition temperature and hydrogen flow rate on the properties of the Al-doped ZnO thin films and amorphous silicon thin-film solar cells  

Science.gov (United States)

A compound of 98 mol% ZnO and 1 mol% Al2O3 (AZO, Al:Zn = 98:2) was sintered at 1350 C as a target and the AZO thin films were deposited on glass using a radio frequency magnetron sputtering system. The effects of deposition temperature (from room temperature to 300 C) on the optical transmission spectrum of the AZO thin films were studied. The Burstein-Moss shift was observed and used to prove that defects in the AZO thin films decreased with increasing deposition temperature. The variations in the optical band gap ( E g) values of the AZO thin films were evaluated from plots of ( ?hv)2= c( h?- E g), revealing that the measured E g values increased with increasing deposition temperature. The effects of the H2 flow rate during deposition (0 %11.76 %, deposition temperature of 200 C) on the crystallization, morphology, resistivity, carrier concentration, carrier mobility, and optical transmission spectrum of the AZO thin films were measured. The chemical structures of the Ar-deposited and 2 % H2-flow rate-deposited AZO thin films (both were deposited at 200 C) were investigated by XPS to clarify the mechanism of improvement in resistivity. The prepared AZO thin films were also used as transparent electrodes to fabricate amorphous silicon thin-film solar cells, and their properties were also measured.

Huang, Chia-Cheng; Wang, Fang-Hsing; Yang, Chen-Fu

2013-09-01

299

Metallization systems for thin film CuInSe/sub 2//CdS solar cells  

Energy Technology Data Exchange (ETDEWEB)

Thin film CuInSe/sub 2//CdS solar cells with efficiency between 8-9% on a small area (4 cm/sup 2/) have been characterized. The quality of the front and back contacts and their effect on the performance of these cells has been examined. Analysis of the dark and light current voltage characteristics show high series resistance. Auger ESCA analysis of the molybdenum (Mo) back contact indicates formation of MoSe/sub 2/ at the CuInSe/sub 2//Mo interface. Copper and indium also are observed to diffuse into the Mo layer. Adhesion of front grid lines using Al, Al-Ag, and In-Ag metals has been found to be sensitive to the processing conditions. Vacuum-deposited Al with minimal oxygen background pressure during deposition appears to be a suitable front contact.

Kapur, V.K.; Choudury, U.V.; Elyash, L.; Meisel, S.; Singh, P.J.; Uno, F.M.

1984-05-01

300

Study of thin-film silicon solar cells at irradiances above ten thousand suns  

International Nuclear Information System (INIS)

[en]We used a tightly focused Gaussian beam of a HeNe laser to study accelerated light-induced degradation (Staebler-Wronski effect) and high photocarrier generation rates in amorphous and microcrystalline silicon thin-film solar cells, at up to13 MW/m2 irradiance. For the experiments, the spot radius was varied from a minimum of 8.6 ?m in the focus to around 1 mm away from the focus. According to COMSOL'' (registered) simulations, even at these high power densities heat diffusion into a glass substrate aided by spreading conduction via the Ag back-contact restricts the temperature rise to less than 14 K. Short-circuit current can be measured directly over a range of irradiances, and the J-V characteristic may be estimated by taking into account shunting by the inactive part of the cell.

2010-11-01

 
 
 
 
301

The performance of thin film solar cells employing photovoltaic Cu 2x Te-CdTe heterojunctions  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper is a short status report on the continuing development of Cu 2xTe-CdTe thin film solar cells for eventual aerospace application. The fabrication and operating characteristics are described, as well as on-earth maintenance, stability to thermal cycling, and resistance to radiation. Experi...

Cusano, D.A.

302

Transport properties of CuGaSe(2)-based thin-film solar cells as a function of absorber composition  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The transport properties of thin-film solar cells based on wide-gap CuGaSe(2) absorbers have been investigated as a function of the bulk [Ga]/[Cu] ratio ranging from 1.01 to 1.33. We find that (i) the recombination processes in devices prepared from absorbers with a composition close to stoichiometr...

Rusu, M.; Bar, M.; Fuertes Marrn, David; Lehmann, Sebastian; Schedel Niedrig, T.; Lux Steiner, M. Ch.

303

Advances in Evaporated Solid-Phase-Crystallized Poly-Si Thin-Film Solar Cells on Glass (EVA)  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Polycrystalline silicon thin-film solar cells on glass obtained by solid-phase crystallization (SPC) of PECVD-deposited a-Si precursor diodes are capable of producing large-area devices with respectable photovoltaic efficiency. This has not yet been shown for equivalent devices made from evaporated ...

O. Kunz; Z. Ouyang; J. Wong; A. G. Aberle

304

Analysis of laser scribes at CIGS thin-film solar cells by localized electrical and optical measurements  

Science.gov (United States)

Laser patterning of thin-film solar cells is essential to perform external serial and integrated monolithic interconnections for module application and has recently received increasing attention. Current investigations show, however, that the efficiency of thin-film Cu(In,Ga)Se2 (CIGS) modules is reduced due to laser scribing also with ultrashort laser pulses. Hence, to investigate the reasons of the laser-induced material modifications, thin-film CIGS solar cells were laser-scribed with femto- and picosecond laser pulses using different scribing procedures and laser processing parameters. Besides standard electrical current voltage (I-V) measurements, additional electrical and optical analysis were performed such as laser beam-induced current (LBIC), dark lock-in thermography (DLIT), and electroluminescence (EL) measurements to characterize and localize electrical losses due to material removal/modifications at the scribes that effecting the electrical solar cell properties. Both localized as well as distributed shunts were found at laser scribe edges whereas the laser spot intensity distribution affecting the shunt formation. Already laser irradiation below the ablation threshold of the TCO film causes material modification inside the thin film solar cell stack resulting in shunt formation as a result of materials melting near the TCO/CIGS interface that probably induces the damage of the pn-junction.

Wehrmann, Anja; Puttnins, Stefan; Hartmann, Lars; Ehrhardt, Martin; Lorenz, Pierre; Zimmer, Klaus

2012-09-01

305

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

The distribution of the electrostatic potential in and between the materials in Cu(In,Ga)Se2 thin-film solar cells has a major impact on their superior performance. This thesis reported on the nanoscale imaging of the electrostatic potential on untreated cross sections of operating Cu(In,Ga)Se2 sola...

Zhang, Zhenhao

306

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

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

307

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

Energy Technology Data Exchange (ETDEWEB)

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].

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

308

Natural evolution inspired design of light trapping structure in thin film organic solar cells  

Science.gov (United States)

Light trapping has been developed to effectively enhance the efficiency of the thin film solar cell by extending the pathlength for light interacting with the active materials. Searching for optimal light trapping design requires a delicate balance among all the competing physical processes, including light refraction, reflection, and absorption. The existing design methods mainly depend on engineers' intuition to predefine the topology of the light-trapping structure. However, these methods are not capable of handling the topological variation in reaching the optimal design. In this work, a systematic approach based on Genetic Algorithm is introduced to design the scattering pattern for effective light trapping. Inspired by natural evolution, this method can gradually improve the performance of light trapping structure through iterative procedures, producing the most favorable structure with minimized reflection and substantial enhancement in light absorption. Both slot waveguide based solar cell and a more realistic organic solar with a scattering layer consisting of nano-scale patterned front layer is optimized to maximize absorption by strongly coupling incident sun light into the localized photonic modes supported by the multilayer system. Rigorous coupled wave analysis (RCWA) is implemented to evaluate the absorbance. The optimized slot waveguide cell achieves a broadband absorption efficiency of 48.1% and more than 3-fold increase over the Yablonovitch limit and the optimized realistic organic cell exhibits nearly 50% average absorbance over the solar spectrum with short circuit current density five times larger than the control case using planar ITO layer.

Wang, Chen; Yu, Shuangcheng; Chen, Wei; Sun, Cheng

2013-09-01

309

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

Energy Technology Data Exchange (ETDEWEB)

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)

Tiwari, A. N.; Romanyuk, Y.

2010-01-15

310

Silicontetrachloride based microcrystalline silicon for application in thin film silicon solar cells  

International Nuclear Information System (INIS)

The replacement of the process gas silane by silicontetrachloride for the deposition of microcrystalline silicon thin films is explored. The films were prepared by plasma enhanced chemical vapor deposition from mixtures of silicontetrachloride and hydrogen. Deposition conditions similar as employed for efficient silane-based microcrystalline silicon solar cells of high deposition rate were applied. Structural and electronic properties of the films are studied by infrared optical absorption and Raman spectroscopies and conductivity measurements. Increasing the flow ratio of silicontetrachloride to hydrogen, the transition from the crystalline to the amorphous state is found to occur in a similar range of flow ratio as in silane-based material. The lowest porosity is observed for a crystalline fraction near 80%. Porosity, void-related microstructure and chlorine content are found to decrease with increasing substrate temperature. For boron doped material deposited at a substrate temperature of 250 deg. C, conductivity values exceeding 50 (? cm)-1 were achieved. This latter material was incorporated as p-layer into microcrystalline pin silicon solar cells. Solar cell efficiencies similar as for solar cells with a silane-based p-layer were obtained.

2004-03-22

311

Light absorption enhancement in thin-film solar cells by embedded lossless silica nanoparticles  

Science.gov (United States)

Embedded silica nanoparticles in thin-film silicon solar cells have some advantages over metal nanoparticles in enhancing optical absorption of silicon such as no loss, better compatibility with antireflection coating and extremely low dangling bond densities and interface recombination velocities. To the best of our knowledge, we have carried out the first systematic study of optical absorption enhancement with silica nanoparticles of different radii, array periods and depths in the silica substrate with the finite-difference time-domain method, and we have obtained the optimum values of the nanoparticle parameters. We discuss the physical mechanism of the optical absorption enhancement in detail and attribute the enhancement to the superposition of the particle scattering effect and the Fabry-Perot resonance effect.

Li, Baozeng; Lin, Jingquan; Lu, Ji; Su, Xiaoxiao; Li, Jie

2013-05-01

312

Studying nanostructured nipple arrays of moth eye facets helps to design better thin film solar cells  

International Nuclear Information System (INIS)

Nipples on the surface of moth eye facets exhibit almost perfect broadband anti-reflection properties. We have studied the facet surface micro-protuberances, known as corneal nipples, of the chestnut leafminer moth Cameraria ohridella by atomic force microscopy, and simulated the optics of the nipple arrays by three-dimensional electromagnetic simulation. The influence of the dimensions and shapes of the nipples on the optics was studied. In particular, the shape of the nipples has a major influence on the anti-reflection properties. Furthermore, we transferred the structure of the almost perfect broadband anti-reflection coatings to amorphous silicon thin film solar cells. The coating that imitates the moth-eye array allows for an increase of the short circuit current and conversion efficiency of more than 40%.

2012-01-01

313

Laser-crystallized microcrystalline SiGe alloys for thin film solar cells  

International Nuclear Information System (INIS)

Thin films of crystalline silicon-germanium (SiGe) alloys could be an interesting material for next generation solar cells. SiGe alloys with a Ge content of approximately 80 at.% have an indirect band gap only slightly smaller than that of Si. However, the first direct optical transition occurs at approximately 1.5 eV, leading to a strongly enhanced optical absorption compared to Si. Thin ?c-SiGe films were prepared by crystallization of evaporated amorphous or nanocrystalline alloys with a pulsed Nd:YAG laser, using homogeneous as well as laser interference methods to achieve lateral grain growth. Structural properties were characterized by atomic force microscopy and transmission electron microscopy. Raman measurements were performed to study possible phase separation and to analyze residual strain in the recrystallized films.

2003-03-03

314

Dielectric back scattering patterns for light trapping in thin-film Si solar cells.  

UK PubMed Central (United Kingdom)

We experimentally compare the light trapping efficiency of dielectric and metallic backscattering patterns in thin-film a-Si:H solar cells. We compare devices with randomly patterned Ag back contacts that are covered with either flat or patterned aluminum-doped ZnO (AZO) buffer layers and find the nanostructure at the AZO/a-Si:H interface is key to achieve efficient light trapping. Simulations show that purely dielectric scattering patterns with flat Ag and a patterned AZO/a-Si:H interface can outperform geometries in which the Ag is also patterned. The scattering from the dielectric patterns is due to geometrical Mie resonances in the AZO nanostructures. The optimized dielectric geometries avoid parasitic Ohmic losses due to plasmon resonances in the Ag, and open the way to a large number of new light trapping designs based on purely dielectric resonant light scattering.

van Lare M; Lenzmann F; Polman A

2013-09-01

315

CdS/CdTe thin-film solar cell with a zinc stannate buffer layer  

Energy Technology Data Exchange (ETDEWEB)

This paper describes an improved CdS/CdTe polycrystalline thin-film solar-cell device structure that integrates a zinc stannate (Zn{sub 2}SnO{sub 4} or ZTO) buffer layer between the transparent conductive oxide (TCO) layer and the CdS window layer. Zinc stannate films have a high bandgap, high transmittance, low absorptance, and low surface roughness. In addition, these films are chemically stable and exhibit higher resistivities that are roughly matched to that of the CdS window layer in the device structure. Preliminary device results have demonstrated that by integrating a ZTO buffer layer in both SnO{sub 2}-based and Cd{sub 2}SnO{sub 4} (CTO)-based CdS/CdTe devices, performance and reproducibility can be significantly enhanced. {copyright} {ital 1999 American Institute of Physics.}

Wu, X.; Sheldon, P.; Mahathongdy, Y.; Ribelin, R.; Mason, A.; Moutinho, H.R.; Coutts, T.J. [National Renewable Energy Laboratory, Golden, Colorado 80401 (United States)

1999-03-01

316

CdS/CdTe Thin-Film Solar Cell with a Zinc Stannate Buffer Layer  

Energy Technology Data Exchange (ETDEWEB)

This paper describes an improved CdS/CdTe polycrystalline thin-film solar-cell device structure that integrates a zinc stannate (Zn2SnO4 or ZTO) buffer layer between the transparent conductive oxide (TCO) layer and the CdS window layer. Zinc stannate films have a high bandgap, high transmittance, low absorptance, and low surface roughness. In addition, these films are chemically stable and exhibit higher resistivities that are roughly matched to that of the CdS window layer in the device structure. Preliminary device results have demonstrated that by integrating a ZTO buffer layer in both SnO2-based and Cd2SnO4 (CTO)-based CdS/CdTe devices, performance and reproducibility can be significantly enhanced

Wu, X.; Sheldon, P.; Mahathongdy, Y.; Ribelin, R.; Mason, A.; Moutinho, H. R.; Coutts, T. J.

1998-10-28

317

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

CERN Multimedia

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...

Israelowitz, Miriam; Cong, Tao; Sureshkumar, Radhakrishna

2013-01-01

318

Effects of Antimony Doping on Cu(In1-x,Gax)Se2 Thin Films and Solar Cells  

Science.gov (United States)

The effects of antimony (Sb) doping into Cu(In1-x,Gax)Se2 (CIGS) thin films and solar cells have been investigated. 10--50-nm-thick Sb thin layers were deposited onto Mo-coated sodalime glass (SLG) and SiOx-coated SLG substrates by vacuum evaporation. CIGS thin films were then deposited by a three-stage process at substrate temperatures of 450--550 C. The grain growth of CIGS thin films was enhanced, and the open-circuit voltage and hence the conversion efficiency improved with the Sb doping when the SLG substrates were used. However, little or no effect was observed when the alkali barrier SiOx layer was deposited on SLG substrates. As a result, we found that Sb doping is beneficial for improving the cell performance when sodium exists simultaneously in CIGS layers.

Yatsushiro, Yuta; Nakakoba, Hiroya; Mise, Takahiro; Kobayashi, Taizo; Nakada, Tokio

2012-10-01

319

Effects of Bi Incorporation on Cu(In1-x,Gax)Se2 Thin Films and Solar Cells  

Science.gov (United States)

The effects of bismuth (Bi) incorporation into Cu(In1-x,Gax)Se2 (CIGS) thin films and solar cells have been investigated. 10--50-nm-thick Bi thin layers were deposited onto Mo-coated soda-lime glass (SLG) and SiOx-coated SLG substrates by vacuum evaporation. CIGS thin films were then deposited by a three-stage process at substrate temperatures of 450--550 C. The grain growth of CIGS thin films was enhanced, and the open-circuit voltage and hence the conversion efficiency was improved by the Bi incorporation when the SLG substrates were used. However, little effect was observed when the alkali barrier SiOx layer was deposited on SLG substrates. As a result, we found that the Bi incorporation is beneficial for improving the cell performance when sodium exists simultaneously in CIGS layers.

Nakakoba, Hiroya; Yatsushiro, Yuta; Mise, Takahiro; Kobayashi, Taizo; Nakada, Tokio

2012-10-01

320

Selective ablation of thin Mo and TCO films with femtosecond laser pulses for structuring thin film solar cells  

International Nuclear Information System (INIS)

We report on recent results on selective ablation of TCO (SnO2,ZnO) and metallic layers as a possible process for structuring thin film solar cells. The multipulse ablation thresholds determined for substrate and various thin films show a parameter window where the films can be completely removed by a single scan without at the same time damaging the underlying material. By employing ultrashort pulsed lasers, nonthermal ablation at repetition rates up to the megahertz regime enables high quality structuring combined with process speeds meeting industrial demands. (orig.)

2007-01-01

 
 
 
 
321

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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,...

Engman, Jessica

322

Effect of back contacts on the characteristics of all thin films Cd/Te/CdS solar cells  

International Nuclear Information System (INIS)

The effect of various contact materials to the CdTe layer, in the film CdTe/CdS solar cells, has been investigated. A buffer layer of ZnTe is used in order to facilitate ohmic contacts to p-type CdTe. The results of junction studies have indicated that Ag makes a Schottky contact, whereas C makes an ohmic contact to all thin film CdTe/CdS solar cells. (author)

1998-01-01

323

Series circuit of organic thin-film solar cells for conversion of water into hydrogen.  

Science.gov (United States)

A series circuit of bulk hetero-junction (BHJ) organic thin-film solar cells (OSCs) is investigated for electrolyzing water to gaseous hydrogen and oxygen. The BHJ OSCs applied consist of poly(3-hexylthiophene) as a donor and [6,6]-phenyl C61 butyric acid methyl ester as an acceptor. A series circuit of six such OSC units has an open circuit voltage (V(oc)) of 3.4 V, which is enough to electrolyze water. The short circuit current (J(sc)), fill factor (FF), and energy conversion efficiency (?) are independent of the number of unit cells. A maximum electric power of 8.86 mW cm(-2) is obtained at the voltage of 2.35 V. By combining a water electrolysis cell with the series circuit solar cells, the electrolyzing current and voltage obtained are 1.09 mA and 2.3 V under a simulated solar light irradiation (100 mW cm(-2), AM1.5G), and in one hour 0.65 mL hydrogen is generated. PMID:23671012

Aoki, Atsushi; Naruse, Mitsuru; Abe, Takayuki

2013-05-13

324

Series circuit of organic thin-film solar cells for conversion of water into hydrogen.  

UK PubMed Central (United Kingdom)

A series circuit of bulk hetero-junction (BHJ) organic thin-film solar cells (OSCs) is investigated for electrolyzing water to gaseous hydrogen and oxygen. The BHJ OSCs applied consist of poly(3-hexylthiophene) as a donor and [6,6]-phenyl C61 butyric acid methyl ester as an acceptor. A series circuit of six such OSC units has an open circuit voltage (V(oc)) of 3.4 V, which is enough to electrolyze water. The short circuit current (J(sc)), fill factor (FF), and energy conversion efficiency (?) are independent of the number of unit cells. A maximum electric power of 8.86 mW cm(-2) is obtained at the voltage of 2.35 V. By combining a water electrolysis cell with the series circuit solar cells, the electrolyzing current and voltage obtained are 1.09 mA and 2.3 V under a simulated solar light irradiation (100 mW cm(-2), AM1.5G), and in one hour 0.65 mL hydrogen is generated.

Aoki A; Naruse M; Abe T

2013-07-01

325

Electron Backscatter Diffraction: An Important Tool for Analyses of Structure-Property Relationships in Thin-Film Solar Cells  

Science.gov (United States)

The present work gives an overview of the application of electron backscatter diffraction (EBSD) in the field of thin-film solar cells, which consist of stacks of polycrystalline layers on various rigid or flexible substrates. EBSD provides access to grain-size and local-orientation distributions, film textures, and grain-boundary types. By evaluation of the EBSD patterns within individual grains of the polycrystalline solar cell layers, microstrain distributions also can be obtained. These microstructural properties are of considerable interest for research and development of thin-film solar cells. Moreover, EBSD may be performed three-dimensionally, by alternating slicing of cross sections in a focused ion-beam machine and EBSD acquisition. To relate the microstructural properties to the electrical properties of individual layers as well as to the device performances of corresponding solar cells, EBSD can be combined with electron-beam-induced current and cathodoluminescence measurements and with various scanning-probe microscopy methods such as Kelvin-probe force, scanning spreading resistance, or scanning capacitance microscopy on identical specimen positions. Together with standard device characterization of thin-film solar cells, these scanning microscopy measurements provide the means for extensive analysis of structure-property relationships in solar-cell stacks with polycrystalline layers.

Abou-Ras, D.; Kavalakkatt, J.; Nichterwitz, M.; Schfer, N.; Harndt, S.; Wilkinson, A. J.; Tsyrulin, K.; Schulz, H.; Bauer, F.

2013-09-01

326

Impact of hydrogen radical-injection plasma on fabrication of microcrystalline silicon thin film for solar cells  

Science.gov (United States)

A plasma-enhanced chemical deposition system with hydrogen radical-injection (RI) is proposed for the fabrication of hydrogenated microcrystalline silicon (?c-Si:H) thin films. The plasma parameters and resultant growth characteristics obtained with the RI-capacitively coupled plasma (RI-CCP) system excited with 60 MHz power were compared with those obtained using a conventional CCP (C-CCP) system. The absolute density of hydrogen (H) radicals was measured by vacuum ultraviolet laser absorption spectroscopy (VUVLAS) to evaluate the effect of RI for controlling the H radical density. A higher density of H radicals was achieved with RI-CCP than with C-CCP by H RI. The crystallinity factor, preferential orientation, defect density, microstructure, and post-deposition oxidation of Si thin films deposited using C-CCP and RI-CCP were investigated. Crystallinity factor of 0.6 was realized with high deposition rate of about 2 nm/s even under a low plasma density using RI-CCP. The defect density of ?c-Si:H thin films prepared using RI-CCP was lower than that in thin films prepared using C-CCP. In addition, post-deposition oxidation of the films with RI-CCP was lower than that with C-CCP. The high performance of RI-CCP for the fabrication of ?c-Si:H thin films for solar cell devices is also demonstrated.

Abe, Yusuke; Kawashima, Sho; Fukushima, Atsushi; Lu, Ya; Takeda, Keigo; Kondo, Hiroki; Ishikawa, Kenji; Sekine, Makoto; Hori, Masaru

2013-01-01

327

Characterisation of Cu(In,Ga)Se2-based thin film solar cells on polyimide  

International Nuclear Information System (INIS)

Thin films of Cu(In,Ga)Se2 (CIGS) were deposited at temperatures below 450 deg. C on polyimide (PI) substrates coated with Mo in a roll-to-roll set up by a combination of co-evaporation and ion-beam techniques. Flexible solar cells ITO/i-ZnO/CdS/CIGS/Mo/PI with and without Na incorporation were then fabricated. The films and solar cells were examined by: X-ray fluorescence spectroscopy (XRF) and Auger electron spectroscopy (AES), to determine the elemental composition, as well as by X-ray diffraction for structure- and scanning electron microscopy (SEM) for morphology-analysis. Photoluminescence (PL) and PL-excitation (PLE) at temperatures from 4.2 to 78 K were also used to estimate the band-gap energy of CIGS, examine the electronic properties and defect nature. The aim of this study was to correlate the incorporation of Na with optical and structural parameters of the CIGS layers as well as with the solar cell performance.

2009-02-02

328

Photoluminescence properties of a-Si:H based thin films and corresponding solar cells  

International Nuclear Information System (INIS)

Amorphous hydrogenated silicon (a-Si:H) is a well-known semiconductor with metastable properties. Direct surface exposure, as it occurs e.g. in rf plasma equipments, introduces damage due to the charged particle bombardment. The paper deals with photoluminiscence properties of virgin, oxide layer covered and chemically treated (in KCN solutions) surfaces of a-Si:H and corresponding solar cell structures. The cyanide treatment improves the electrical characteristics of MOS structures as well as solar cells. X-ray diffraction at grazing incidence and reflectance spectroscopy complete the study. The photoluminescence measurements were performed at liquid helium temperatures at 6 K using an Ar laser and lock-in signal recording device containing the PbS and Ge photodetectors. Photoluminescence bands were observed as broad luminescent peaks between 1.05-1.7 eV. Two new peaks were detected at 1.38 and 1.42 eV. The evolution of the band at ?1.2 eV related to microcrystalline silicon is investigated. The fitting and simulation of photoluminiscence spectra are presented. The surface luminescent properties of a-Si:H based structures (double layers, single thin film solar cells) before and after the passivation are compared with those of very thin oxide layers and chemically treated surfaces.

2003-06-02

329

Dyadic Greens functions of thin films: Applications within plasmonic solar cells  

DEFF Research Database (Denmark)

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 Greens function formulation. Based on the dyadic Greens function (Greens 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 Greens 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.

Jung, Jesper; Sndergaard, Thomas

2011-01-01

330

CIGSS Thin Film Solar Cells: Final Subcontract Report, 10 October 2001-30 June 2005  

Energy Technology Data Exchange (ETDEWEB)

This report describes the I-III-VI2 compounds that are developing into a promising material to meet the energy requirement of the world. CuInSe2 (CIS) and its alloy with Ga and S have shown long-term stability and highest conversion efficiency of 19.5%. Among the various ways of preparing CuIn1-xGaxSe2-ySy (CIGSS)/CdS thin-film solar cells, co-evaporation and sputtering techniques are the most promising. Sputtering is an established process for very high-throughput manufacturing. ARCO Solar, now Shell Solar, pioneered the work in CIS using the sputtering technique. The two-stage process developed by ARCO Solar involved sputtering of a copper and indium layer on molybdenum-coated glass as the first step. In the second step, the copper-indium layers were exposed to a selenium-bearing gas such as hydrogen selenide (H2Se) mixed with argon. The hydrogen selenide breaks down and leaves selenium, which reacts and mixes with the copper and indium in such a way to produce very high-quality CIS absorber layer. Sputtering technology has the added advantage of being easily scaled up and promotes roll-to-roll production on flexible substrates. Preliminary experiments were carried out. ZnO/ZnO:Al deposition by RF magnetron sputtering and CdS deposition by chemical-bath deposition are being carried out on a routine basis.

Dhere, N. G.

2006-02-01

331

Compatibility of glass textures with E-beam evaporated polycrystalline silicon thin-film solar cells  

Science.gov (United States)

For polycrystalline silicon thin films on glass, E-beam evaporation capable of high-rate deposition of amorphous silicon (a-Si) film precursor up to 1 ?m/minute is a potentially low-cost solution to replace the main stream a-Si deposition methodplasma enhanced chemical vapour deposition (PECVD). Due to weak absorption of near infrared light and a target of 2 ?m Si absorber thickness, glass substrate texturing as a general way of light trapping is vital to make E-beam evaporation commercially viable. As a result, the compatibility of e-beam evaporation with glass textures becomes essential. In this paper, glass textures with feature size ranging from 200 nm to 1.5 micron and root-mean-square roughness (Rms) ranging from 10 nm to 200 nm are prepared and their compatibility with e-beam evaporation is investigated. This work indicates that e-beam evaporation is only compatible with small smooth submicron sized textures, which enhances J sc by 21 % without degrading V oc of the cells. Such textures improve absorption-based J sc up to 45 % with only 90 nm SiN x as the antireflection and barrier layer; however, the enhancement degrades to 10 % with 100 nm SiO x +90 nm SiN x as the barrier layer. The absorption-based J sc is abbreviated by J sc(A), which is deduced by integrating the multiplication product of the measured absorption and the AM1.5G spectrum in the wavelength range 300-1050 nm assuming unity internal quantum efficiency at each wavelength. This investigation is also relevant to other thin-film solar cell technologies which require evaporating the absorber onto textured substrate/superstrate.

Cui, Hongtao; Campbell, Patrick R.; Green, Martin A.

2013-06-01

332

Thin film solar cell and its production method. Hakumaku taiyo denchi oyobi sono seizo hoho  

Energy Technology Data Exchange (ETDEWEB)

In order to improve the conversion efficiency of the amorphous silicon solar cell, a proposal was made to build a tandem structure by laminating a number of pin junction structure which were different each other in optical gap of i-layer. With this structure, however, it is very difficult to keep the photo-deterioration below 10 % even if making the i-layer as thin as 100% nm. This invention provides a thin film solar cell. The material having higher optical gap than that of the amorphous silicon is used on the i-layer of the cell of the light incidence side of the tandem cell to heighten the energy conversion efficiency with less optical deterioration. For that purpose, the i-layer of the cell near the light incidence side is composed of the amorphous silicon oxide (a-SiO:H) expressed by the general formula of a-Si(1-x)Ox, (0.02 < x < 0.1). This a-SiO:H can be formed by the decomposition of mixture gas of SiH4, CO2, and H2. It is preferable to adopt the ratio of H2 to SiH4, in the range between 15 and 30. 5 figs.

Ota, H.

1993-10-08

333

Band gap engineering of hydrogenated amorphous carbon thin films for solar cell application  

Science.gov (United States)

In this work, self bias variation, nitrogen introduction and oxygen plasma (OP) treatment approaches have been used for tailoring the band gap of hydrogenated amorphous carbon (a-C:H) thin films. The band gap of a-C:H and modified a- C:H films is varied in the range from 1.25 eV to 3.45 eV, which is found to be nearly equal to the full solar spectrum (1 eV- 3.5 eV). Hence, such a-C:H and modified a-C:H films are found to be potential candidate for the development of full spectrum solar cells. Besides this, computer aided simulation with considering variable band gap a-C:H and modified a- C:H films as window layer for amorphous silicon p-i-n solar cells is also performed by AFORS-HET software and maximum efficiency as ~14 % is realized. Since a-C:H is hard material, hence a-C:H and modified a-C:H films as window layer may avoid the use of additional hard and protective coating particularly in n-i-p configuration.

Dwivedi, Neeraj; Kumar, Sushil; Dayal, Saurabh; Rauthan, C. M. S.; Panwar, O. S.; Malik, Hitendra K.

2012-10-01

334

Effect of carrier injection stress in thin film solar cells by impedance spectroscopy.  

UK PubMed Central (United Kingdom)

In amorphous silicon solar cells, degradation is directly related to V(oc), FF and cell performance. The dependence of the stability of thin film amorphous silicon solar cells is studied in terms of the volume fraction of B2H6 in the p-layer. When the volume fraction of B2H6 is increased by an order of magnitude, the doping-induced defects tend to increase quite rapidly. Low-doped p-type a-SiO(x) layers had better initial properties but rapidly degraded. Heavily doped p-type a-SiO(x) layers had lower initial properties but displayed better stability. The improvement in stability is explained in conjunction with the capacitance and resistance values of impedance spectroscopy. When the B2H6 gas flow rate is increased, the cell is degraded showing a capacitance decay decrease from 51.75% to less than 18.18%. In addition, the increase in the resistance decreased from 90.90% to 11.73%.

Park S; Lee S; Park J; Kim Y; Yoon K; Shin C; Baek S; Lee YJ; Yi J

2012-04-01

335

Effect of carrier injection stress in thin film solar cells by impedance spectroscopy.  

Science.gov (United States)

In amorphous silicon solar cells, degradation is directly related to V(oc), FF and cell performance. The dependence of the stability of thin film amorphous silicon solar cells is studied in terms of the volume fraction of B2H6 in the p-layer. When the volume fraction of B2H6 is increased by an order of magnitude, the doping-induced defects tend to increase quite rapidly. Low-doped p-type a-SiO(x) layers had better initial properties but rapidly degraded. Heavily doped p-type a-SiO(x) layers had lower initial properties but displayed better stability. The improvement in stability is explained in conjunction with the capacitance and resistance values of impedance spectroscopy. When the B2H6 gas flow rate is increased, the cell is degraded showing a capacitance decay decrease from 51.75% to less than 18.18%. In addition, the increase in the resistance decreased from 90.90% to 11.73%. PMID:22849108

Park, Seungman; Lee, Sunhwa; Park, Jinjoo; Kim, Youngkuk; Yoon, Kichan; Shin, Chonghoon; Baek, Seungsin; Lee, Youn-Jung; Yi, Junsin

2012-04-01

336

Band offset of high efficiency CBD-ZnS/CIGS thin film solar cells  

International Nuclear Information System (INIS)

The band offset at the CBD-ZnS/Cu(In,Ga)Se2 (CIGS) interface and solar cells performance were investigated by means of X-ray photoelectron spectroscopy (XPS). The valence band maximum and valence band offset at the chemical bath deposition (CBD)-ZnS/CIGS interface region was directly measured using a XPS spectral multiplot. We found that the conduction band offset (CBO) at the CBD-ZnS/CIGS (ordered vacancy compound, OVC) interface was smaller than that of the evaporated ZnS/CIGS (OVC) interface. However, the CBO for the CBD-ZnS/CIGS (OVC) interface was still quite large for fabrication of high efficiency devices, although, in fact, high efficiency CBD-ZnS/CIGS devices were fabricated with good run-to-run reproducibility. The bandgap dependence of cell performance for CBD-ZnS/CIGS devices (large CBO) showed a tendency similar to that of CBD-CdS/CIGS devices (small CBO). Therefore, the observed decrease in cell performance for high bandgap devices is not interpreted in terms of the CBO. These results suggest that the band offset is not the predominant factor in achieving high efficiency CBD-ZnS/CIGS thin film solar cells. This finding suggests that the recombination mechanism of those wide-gap alloys is a bulk recombination

2003-05-01

337

Band offset of high efficiency CBD-ZnS/CIGS thin film solar cells  

Energy Technology Data Exchange (ETDEWEB)

The band offset at the CBD-ZnS/Cu(In,Ga)Se{sub 2} (CIGS) interface and solar cells performance were investigated by means of X-ray photoelectron spectroscopy (XPS). The valence band maximum and valence band offset at the chemical bath deposition (CBD)-ZnS/CIGS interface region was directly measured using a XPS spectral multiplot. We found that the conduction band offset (CBO) at the CBD-ZnS/CIGS (ordered vacancy compound, OVC) interface was smaller than that of the evaporated ZnS/CIGS (OVC) interface. However, the CBO for the CBD-ZnS/CIGS (OVC) interface was still quite large for fabrication of high efficiency devices, although, in fact, high efficiency CBD-ZnS/CIGS devices were fabricated with good run-to-run reproducibility. The bandgap dependence of cell performance for CBD-ZnS/CIGS devices (large CBO) showed a tendency similar to that of CBD-CdS/CIGS devices (small CBO). Therefore, the observed decrease in cell performance for high bandgap devices is not interpreted in terms of the CBO. These results suggest that the band offset is not the predominant factor in achieving high efficiency CBD-ZnS/CIGS thin film solar cells. This finding suggests that the recombination mechanism of those wide-gap alloys is a bulk recombination.

Nakada, Tokio; Hongo, Masashi; Hayashi, Eiji

2003-05-01

338

Interface properties of Cd-free buffer layers on on CIGSe thin film solar cells  

International Nuclear Information System (INIS)

In order to replace the toxic Cadmium, the substitution of the CdS buffer layer in thin film solar cells based on Cu(In,Ga)(S,Se)2 (CIGSSe) is of great interest. Alternative buffer layers like (In,Al)2S3, In2S3, or (Zn1-x,Mgx)O deposited by conventional sputter and chemical bath deposition techniques, have shown efficiencies close to or comparable to those of CdS containing solar cells. To understand the chemical and electronic properties of these buffer layers and its influence on the absorber, we studied the buffer-absorber interface using photoelectron spectroscopy (XPS, UPS) and inverse photoelectron spectroscopy (IPES). The combination of these non-destructive techniques provides detailed information about the chemical properties of the studied surface, as well as can be used for a direct determination of the conduction and valence band alignment at the heterojunction. Band-gap values at the surface as derived by UPS and IPES are also verified by electron energy loss spectroscopy (EELS). The results are discussed in conjunction with the respective cell parameters.

2010-01-01

339

Fabrication of Cu2ZnSnS4 Thin Film Solar Cell Using Single Step Electrodeposition Method  

Science.gov (United States)

Cu2ZnSnS4 (CZTS) thin films were deposited onto Mo-coated and tin-doped indium oxide (ITO) coated glass substrates by using single step electrodeposition technique followed by annealing in N2 + H2S atmosphere. Subsequently, they were applied to the fabrication of thin film solar cells. Upon annealing, the amorphous nature of as-deposited precursor film changes into polycrystalline kesterite crystal structure with uniform and densely packed surface morphology. Energy dispersive X-ray spectroscopy (EDS) study reveals that the deposited thin films are nearly stoichiometric. Optical absorption study shows the band gap energy of as-deposited CZTS thin films is 2.7 eV whereas, after annealing, it is found to be 1.53 eV. The solar cell fabricated with CZTS absorber layer, showed the best conversion efficiency (?) 1.21% for 0.44 cm2 with open-circuit voltage (Voc) = 315 mV, short-circuit current density (Jsc) = 12.27 mA/cm2 and fill factor (FF) = 0.31.

Pawar, Sambhaji M.; Pawar, Bharati S.; Gurav, Kishor V.; Bae, Do Won; Kwon, Se Han; Kolekar, Sanjay S.; Kim, Jin Hyeok

2012-10-01

340

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

Science.gov (United States)

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.

Munn, Carson; Haran, Shivan; Seok, Ilwoo

2013-04-01

 
 
 
 
341

Preparation of thin films, with base to precursor materials of type Cu-In-Se elaborated by electrodeposition for the solar cells elaboration  

International Nuclear Information System (INIS)

Thin films of chalcogenide compounds are promising because they have excellent optoelectronic characteristics to be applied in solar cells. In particular, CuInSe2 and Cd Te thin films have shown high solar to electrical conversion efficiency. However, this efficiency is limited by the method of preparation, in this case, physical vapor deposition techniques are used. In order to increase the area of deposition t is necessary to use chemical methods, for example, electrodeposition technique. In this paper, the preparation of Cu-In-Se precursors thin films by electrochemical method is reported. These precursors were used to build solar cells with 7.9 % of efficiency. (Author)

1999-01-01

342

TiO{sub 2} thin films as protective material for transparent-conducting oxides used in Si thin film solar cells  

Energy Technology Data Exchange (ETDEWEB)

Nb-doped TiO{sub 2} films have been fabricated by RF magnetron sputtering as protective material for transparent-conducting oxide (TCO) films used in Si thin film solar cells. It is found that TiO{sub 2} has higher resistance against hydrogen radical exposure, utilizing the hot-wire CVD (catalytic CVD) apparatus, compared with SnO{sub 2} and ZnO. Further, the minimum thickness of TiO{sub 2} film as protective material for TCO was experimentally investigated. Electrical conductivity of TiO{sub 2} in the as-deposited film is found to be {approx}10{sup -6}S/cm due to the Nb doping. Higher conductivity of {approx}10{sup -2}S/cm is achieved in thermally annealed films. Nitrogen treatments of Nb-doped TiO{sub 2} film have been also performed for improvements of optical and electric properties of the film. The electrical conductivity becomes 4.5x10{sup -2}S/cm by N{sub 2} annealing of TiO{sub 2} films at 500{sup o}C for 30min. It is found that the refractive index n of Nb-doped TiO{sub 2} films can be controlled by nitrogen doping (from n=2.2 to 2.5 at l = 550nm) using N{sub 2} as a reactive gas. The controllability of n implies a better optical matching at the TCO/p-layer interface in Si thin film solar cells. (author)

Natsuhara, H.; Matsumoto, K.; Yoshida, N.; Nonomura, S. [Environmental and Renewable Energy Systems Division, Graduate School of Engineering, Gifu University, 1-1 Yanagido, Gifu 501 1193 (Japan); Itoh, T. [Electrical and Electronic Engineering, Faculty of Engineering, Gifu University, 1-1 Yanagido, Gifu 501 1193 (Japan); Fukawa, M.; Sato, K. [Research Center, Asahi Glass Co., Ltd., 1150 Hazawa-cho, Kanagawa-ku, Yokohama 221 8755 (Japan)

2006-11-06

343

Integrated Cu/sub x/S-CdS thin film solar cell panels with higher output voltages  

Energy Technology Data Exchange (ETDEWEB)

Large-area production of solar cell modules is made possible by applying integration techniques on thin film Cu/sub x/S-CdS solar cells. Integrated modules with output voltages matched to various loads can be realized on a single substrate covered by a single front glass with an integrated front contact. Thus the problem of hermetic sealing can be easily solved. The thin film modules promise to be very reliable. Two different types of modules, both with outer dimensions of 29.5*14.5 cm/sup 2/, are fabricated. The first type consists of 8 cells connected in series with an output current of 0.5 A at 2.8 v, the other of 18 cells with an output current of 0.2 A at 6 V, related to AM 1.5 illumination (85 mW/cm/sup 2/). 6 refs.

Arndt, W.; Bilger, G.; Pfisterer, F.; Schock, H.W.; Woerner, J.; Bloss, W.H.

1981-01-01

344

CdTe thin film solar cells with reduced CdS film thickness  

International Nuclear Information System (INIS)

A study was performed to reduce the CdS film thickness in CdTe thin film solar cells to minimize losses in quantum efficiency. Using close space sublimation deposition for CdS and CdTe a maximum efficiency of ? 9.5% was obtained with the standard CdS film thickness of ? 160 nm. Reduction of the film CdS thickness to less than 100 nm leads to poor cell performance with ? 5% efficiency, mainly due to a lower open circuit voltage. An alternative approach has been tested to reduce the CdS film thickness (? 80 nm) by depositing a CdS double layer. The first CdS layer was deposited at high substrate temperature in the range of 520-540 deg. C and the second CdS layer was deposited at low substrate temperature of ? 250 deg. C. The cell prepared using a CdS double layer show better performance with cell efficiency over 10%. Quantum efficiency measurement confirmed that the improvement in the device performance is due to the reduction in CdS film thickness. The effect of double layer structure on cell performance is also observed with chemical bath deposited CdS using fluorine doped SnO2 as substrate.

2011-08-31

345

Some phenomena in CdTe/CdS thin film solar cells made by close-spaced sublimation  

Energy Technology Data Exchange (ETDEWEB)

CdTe/CdS heterojunction thin film solar cells of 11.7% efficiency have been made by close-spaced sublimation of CdTe. Some results regarding the influence of the CdCl[sub 2] treatment and contacting are given stressing the requirement of more in-depth analysis of the CdTe cells made by different processes in order to understand the common and basic mechanisms better. (author)

Bonnet, Dieter; Henrichs, Beate; Richter, Hilmar (Battelle-Institut e.V., Frankfurt am Main (Germany))

1992-01-01

346

Fabrication and characterization of highly efficient thin-film polycrystalline-silicon solar cells based on aluminium-induced crystallization  

International Nuclear Information System (INIS)

Thin-film polycrystalline-silicon solar cells might become an alternative to bulk silicon solar cells if sufficiently high efficiencies can be obtained. In this work we made pc-Si layers using aluminium-induced crystallization and thermal CVD on alumina substrates. By using plasma texturing and optimizing the cell structure, we increased the current density of our cells and achieved a cell efficiency of 8.0%. At present, our cell efficiency seems to be mainly limited by the presence in our layers of a high density of electronically active intragrain defects. Intragrain quality improvement will therefore be very important to further increase our pc-Si cell efficiency.

2008-08-30

347

Enhanced photocurrent in thin-film amorphous silicon solar cells via shape controlled three-dimensional nanostructures.  

Science.gov (United States)

In this paper, we have explored manufacturable approaches to sub-wavelength controlled three-dimensional (3D) nano-patterns with the goal of significantly enhancing the photocurrent in amorphous silicon solar cells. Here we demonstrate efficiency enhancement of about 50% over typical flat a-Si thin-film solar cells, and report an enhancement of 20% in optical absorption over Asahi textured glass by fabricating sub-wavelength nano-patterned a-Si on glass substrates. External quantum efficiency showed superior results for the 3D nano-patterned thin-film solar cells due to enhancement of broadband optical absorption. The results further indicate that this enhanced light trapping is achieved with minimal parasitic absorption losses in the deposited transparent conductive oxide for the nano-patterned substrate thin-film amorphous silicon solar cell configuration. Optical simulations are in good agreement with experimental results, and also show a significant enhancement in optical absorption, quantum efficiency and photocurrent. PMID:22997169

Hilali, Mohamed M; Yang, Shuqiang; Miller, Mike; Xu, Frank; Banerjee, Sanjay; Sreenivasan, S V

2012-09-20

348

Applications of microcrystalline hydrogenated cubic silicon carbide for amorphous silicon thin film solar cells  

International Nuclear Information System (INIS)

We demonstrated the fabrication of n-i-p type amorphous silicon (a-Si:H) thin film solar cells using phosphorus doped microcrystalline cubic silicon carbide (?c-3C-SiC:H) films as a window layer. The Hot-wire CVD method and a covering technique of titanium dioxide TiO2 on TCO was utilized for the cell fabrication. The cell configuration is TCO/TiO2/n-type ?c-3C-SiC:H/intrinsic a-Si:H/p-type ?c- SiCx (a-SiCx:H including ?c-Si:H phase)/Al. Approximately 4.5% efficiency with a Voc of 0.953 V was obtained for AM-1.5 light irradiation. We also prepared a cell with the undoped a-Si1-xCx:H film as a buffer layer to improve the n/i interface. A maximum Voc of 0.966 V was obtained.

2008-01-15

349

Thin Dielectric Films Containing Tb3+ Ions For Application In Thin Film Solar Cells  

International Nuclear Information System (INIS)

Thin transparent dielectric films containing Tb3+ are developed for application as spectral converters of the solar spectrum in thin film silicon solar cells. The results on the deposition and characterization of thin SiO2 and Al2O3 films containing Tb3+ ions are presented. The films are prepared by RF magnetron co-sputtering, a well established technique for large area coatings. Photoluminescence (PL) is measured at room temperature, using the 488 nm line of an Ar laser and a nitrogen-cooled CCD camera attached to a monochromator. The dependence of the PL intensity on the concentration of Tb in the film is studied. It is found that the intensity exhibits a maximum at about 1 at.%. Annealing studies are performed on SiO2:Tb with two different methods to improve the PL intensity. In both regimes of annealing, the best results for thin SiO2:Tb films are obtained in the temperature range of 650-700 deg. C. After treatment at this temperature the Tb PL increases 2.5-3 times.

2010-01-21

350

Amorphous Thin Films for Solar-Cell Applications: Silicon is deposited at high rates by magnetron sputtering; MIS structures that exhibit photovoltaic response are fabricated.  

Science.gov (United States)

This citation summarizes a one-page announcement of technology available for utilization. Investigations of magnetron sputtering as a technology for the large-scale manufacture of high-efficiency, thin-film, amorphous silicon solar photovoltaic cells are ...

1982-01-01

351

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

1995-08-01

352

Investigation of recombinatoric loss mechanisms in Cu(In,Ga)Se2 thin film solar cells  

International Nuclear Information System (INIS)

Today solar cells based on the compound semiconductor Cu(In,Ga)Se2 (CIGSe) present the highest lab scale efficiency among all thin-film technologies. The performance of elementary cells in photovoltaic modules might however be different due to thicker conductive ZnO:Al window layers, missing anti-reflection coating and occasionally less defined absorber formation on large scales. One approach to improve the elementary cell efficiency is to fine-tune the absorber composition and the in-depth band gap grading. In this work we investigated CIGSe samples with varied absorber composition in order to quantify the minority carrier collection efficiency (CE). CE is directly related to the electron diffusion length LD,n and the characteristics of the space charge region (SCR). LD,n was deduced by relating the inverse internal quantum efficiency to the penetration depth of incident photons and the SCR characteristics were obtained from capacitance-profiling of the samples. Based on these results we discuss the different photovoltaic performance observed for samples with varied CIGSe absorber composition.

2011-01-01

353

Photoluminescence study of polycrystalline CdS/CdTe thin film solar cells  

International Nuclear Information System (INIS)

To achieve high efficiencies in CdS/CdTe thin film solar cells, it is known that a CdCl2 activation process is necessary. In addition, the presence of oxygen during this treatment can have a beneficial effect. The mechanisms involved in this process are not fully understood. In this work, we present a photoluminescence (PL) study of two sample types: cells that received their CdCl2 activation in an air ambient and cells that were treated in vacuum. The luminescence at the front (through the glass substrate) and at the back surfaces (after the partial removal of the back contact by ion sputtering) is investigated. Three main luminescence bands are observed: an excitonic emission around 1.59 eV, an emission band at 1.55 eV and a broad band at 1.4 eV, related to cadmium vacancy-chlorine defect complexes. The 1.55 eV emission is shown to be related to oxygen. Using measurements at very low excitation intensity, we were able to resolve two components: a donor-acceptor pair (DAP) transition and a free electron-acceptor transition. The acceptor level involved is located at approximately 47 meV above the valence band. The 1.4 eV band, related to a cadmium vacancy-chlorine complex, is broader at the junction than at the free surface and shifted to lower energy, possibly related to sulfur interdiffusion at the interface.

2005-06-01

354

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

Energy Technology Data Exchange (ETDEWEB)

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 a single light path but to a strong reduction of the cell current in the infrared part of the spectrum. Conversely, a current enhancement is shown with increasing front electrode haze up to a saturation of the current gain. This saturation correlates remarkably well with the haze of the front electrode calculated in silicon. This allows us to clarify the requirements for the front electrodes of micromorph cells. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Boccard, Mathieu; Cuony, Peter; Battaglia, Corsin; Despeisse, Matthieu; Ballif, Christophe [Ecole Polytechnique Federale de Lausanne (EPFL), Institute of Microengineering (IMT), Photovoltaics and Thin Film Electronics Laboratory, Rue A.-L. Breguet 2, 2000 Neuchatel (Switzerland)

2010-11-15

355

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

Science.gov (United States)

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

Guo, Wei; Liu, Bing

2012-12-12

356

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

UK PubMed Central (United Kingdom)

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%.

Guo W; Liu B

2012-12-01

357

CIGS thin film solar cell prepared by reactive co-sputtering  

Science.gov (United States)

The reactive co-sputtering was developed as a new way of preparing high quality CuInGaSe2(CIGS) films from two sets of targets; Cu0.6Ga 0.4 and Cu0.4In0.6 alloy and Cu and (In0.7Ga0.3)2Se3 compound targets. During sputtering, Cu, In, Ga metallic elements as well as the compound materials were reacted to form CIGS simultaneously in highly reactive elemental Se atmosphere generated by a thermal cracker. CIGS layer had been grown on Mo/soda-lime glass(SLG) at 500C. For both sets of targets, we controlled the composition of CIGS thin film by changing the RF power for target components. All the films showed a preferential (112) orientation as observed from X-ray diffraction analysis. The composition ratios of CIGS were easily set to 0.71-0.95, 0.10-0.30 for [Cu]/[III] and [Ga]/[III], respectively. The grain size and the surface roughness of a CIGS film increased as the [Cu]/[III] ratios increased. The solar cells were fabricated using a standard base line process in the device structure of grid/ITO/i-ZnO/CdS/CIGS/Mo/ SLG. The best performance was obtained the performance of Voc = 0.45 V, Jsc =35.6, FF = 0.535, ? = 8.6% with a 0.9 ?m-CIGS solar cell from alloy targets while Voc = 0.54 V, Jsc =30.8, FF = 0.509, ? = 8.5% with a 0.8 ?m-CIGS solar cell from Cu and (In0.7Ga0.3)2Se3.

Kim, Jeha; Lee, Ho-Sub; Park, Nae-Man

2013-09-01

358

Cu2ZnSnS4 Thin Film Solar Cells Utilizing Sulfurization of Metallic Precursor Prepared by Simultaneous Sputtering of Metal Targets  

Science.gov (United States)

Cu2ZnSnS4 (CZTS) thin films were prepared by simultaneous sputtering of metallic targets and sulfurizing a metallic precursor under elemental sulfur atmosphere in a sealed tube. Subsequently, they were applied to the fabrication of thin film solar cells. The precursors with desired compositional ratio and thickness were obtained by controlling the area ratio of sputtering targets and also sputtering parameters. We have succeeded in obtaining high-quality polycrystalline CZTS thin films by sulfurization under a sulfur vapor pressure higher than atmospheric pressure. A CZTS-based solar cell with 3.7% conversion efficiency was obtained from CZTS films sulfurized at 590 C for 7 min.

Momose, Noritaka; Htay, Myo Than; Yudasaka, Takuto; Igarashi, Shigeo; Seki, Takuro; Iwano, Shota; Hashimoto, Yoshio; Ito, Kentaro

2011-01-01

359

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

Energy Technology Data Exchange (ETDEWEB)

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.

Slafer, D.; Dalal, V.

2012-03-01

360

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.

2011-08-31

 
 
 
 
361

Effect on electron beam treatment of radio frequency sputtered i-ZnO thin films for solar cell applications.  

UK PubMed Central (United Kingdom)

Intrinsic ZnO (i-ZnO) thin films were prepared using radio frequency (RF) sputtering method with working pressure range of 1-20 mTorr and treated by electron beam (e-beam) irradiation unit with 300 W of RF power and 2.5 kV of DC power for 5 min. As working pressure increased to 20 mTorr, deposition rate of samples gradually decreased from 0.3 angstroms/sec to 0.18 angstroms/sec and grain size from 23.6 nm to 16.0 nm. After e-beam treatment on RF sputtered i-ZnO thin films with increasing of working pressure, thickness were totally declined by 10% and grain sizes were grown bigger. The electrical properties of e-beam treated samples were remarkably improved to be - 10(18) cm(-3) of carrier concentration, 2-7 cm2/Vs of Hall mobility and - 10(-1) omega x cm of resistivity. Transmittance of e-beam treated samples were up to -90% and optical bandgap increased to 3.27-3.31 eV, resulted from decline of thickness. The better properties of ZnO thin films as a buffer layer in thin film solar cells could be obtained by e-beam treatment method.

Jeong C; Kim D

2013-08-01

362

Effects of preannealing temperature of ZnO thin films on the performance of dye-sensitized solar cells  

Energy Technology Data Exchange (ETDEWEB)

The preferred (002) orientation zinc oxide (ZnO) nanocrystalline thin films have been deposited on FTO-coated glass substrates by sol-gel spin-coating technology and rapid thermal annealing for use in dye-sensitized solar cells (DSSC). The effects of preannealing temperature (100 and 300 C) on the microstructure, morphology and optical properties of ZnO thin films were studied. The ZnO thin films were characterized by X-ray diffraction (XRD), scanning electron microscopic (SEM) and Brunauer-Emmett-Teller (BET) analysis. The photoelectric performance of DSSC was studied by I-V curve and the incident photon-to-current conversion efficiency (IPCE), respectively. From the results, the intensities of (002) peaks of ZnO thin films increases with increasing preannealing temperature from 100 C to 300 C. The increase in pore size and surface area of ZnO films crystallized at the increased preannealing temperature contributed to the improvement on the absorption of N3 dye onto the films, the short-circuit photocurrent (J{sub sc}) and open-circuit voltage (V{sub oc}) of DSSC. The higher efficiency ({eta}) of 2.5% with J{sub sc} and V{sub oc} of 8.2 mA/cm{sup 2} and 0.64 V, respectively, was obtained by the ZnO film preannealed at 300 C. (orig.)

Kao, M.C.; Chen, H.Z.; Young, S.L. [Hsiuping Institute of Technology, Department of Electronic Engineering, Taichung (China)

2010-03-15

363

Effect on electron beam treatment of radio frequency sputtered i-ZnO thin films for solar cell applications.  

Science.gov (United States)

Intrinsic ZnO (i-ZnO) thin films were prepared using radio frequency (RF) sputtering method with working pressure range of 1-20 mTorr and treated by electron beam (e-beam) irradiation unit with 300 W of RF power and 2.5 kV of DC power for 5 min. As working pressure increased to 20 mTorr, deposition rate of samples gradually decreased from 0.3 angstroms/sec to 0.18 angstroms/sec and grain size from 23.6 nm to 16.0 nm. After e-beam treatment on RF sputtered i-ZnO thin films with increasing of working pressure, thickness were totally declined by 10% and grain sizes were grown bigger. The electrical properties of e-beam treated samples were remarkably improved to be - 10(18) cm(-3) of carrier concentration, 2-7 cm2/Vs of Hall mobility and - 10(-1) omega x cm of resistivity. Transmittance of e-beam treated samples were up to -90% and optical bandgap increased to 3.27-3.31 eV, resulted from decline of thickness. The better properties of ZnO thin films as a buffer layer in thin film solar cells could be obtained by e-beam treatment method. PMID:23882802

Jeong, Chaehwan; Kim, Dongjin

2013-08-01

364

Damp-Heat Induced Degradation of Transparent Conducting Oxides for Thin-Film Solar Cells: Preprint  

Energy Technology Data Exchange (ETDEWEB)

The stability of intrinsic and Al-doped single- and bi-layer ZnO for thin-film CuInGaSe2 solar cells, along with Al-doped Zn1-xMgxO alloy and Sn-doped In2O3 (ITO) and F-doped SnO2, was evaluated by direct exposure to damp heat (DH) at 85oC and 85% relative humidity. The results show that the DH-induced degradation rates followed the order of Al-doped ZnO and Zn1-xMgxO >> ITO > F:SnO2. The degradation rates of Al:ZnO were slower for films of higher thickness, higher substrate temperature in sputter-deposition, and with dry-out intervals. As inferred from the optical micro-imaging showing the initiation and propagation of degrading patterns and regions, the degradation behavior appears similar for all TCOs, despite the obvious difference in the degradation rate. A degradation mechanism is proposed to explain the temporal process involving thermal hydrolysis.

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

2008-05-01

365

Photoluminescence study of highly efficient CdTe thin film solar cells  

Energy Technology Data Exchange (ETDEWEB)

Highly efficient CdTe thin film solar cells with a glass/CdS/CdTe/Cu-doped carbon/Ag structure, were characterized by low temperature photoluminescence (PL) measurement. A broad 1.42eV band probably due to V{sub Cd}-Cl defect complexes appeared as a result of the CdCl{sub 2} treatment. In the PL spectra of the heat-treated CdTe after the screen-printing of the Cu-doped carbon paste, a neutral-acceptor bound exciton (A{sub Cu}{sup 0}, X) line at 1.590eV was observed, suggesting that Cu atoms were incorporated into CdTe as effective acceptors after the heat treatment. Furthermore, CdS/CdTe junction PL was measured, and two broad emissions at around 1.52 and 1.37eV, lower than the PL peak energy in the CdTe surface were observed. This result indicates that CdS{sub 1{minus}x}Te{sub x} mixed crystal layer was formed at the CdS/CdTe interface.

Okamoto, T.; Amin, N.; Yamada, A. [Tokyo Inst. of Tech. (Japan)] [and others

1997-12-31

366

Thin film solar cell and its production method; Hakumaku taiyo denchi oyobi sono seizo hoho  

Energy Technology Data Exchange (ETDEWEB)

This invention provides a thin film solar cell with a high photoelectric conversion efficiency. A rugged film of amorphous or fine-crystalline material having an ability of scattering the light is placed on the n-layer or p-layer of the backside of the semiconductor photoelectric conversion active layer. Then the transparent electrode film and reflection film made of metal are laminated on it. The height difference between the mountain part and the valley part of the rugged film of amorphous or fine-crystalline material is about 400 nm, and the horizontal distance between the mountain part and the adjacent valley part is about 700 nm on an average. The formation of rugged film on the n-layer or p-layer is done by vapor deposition. The deposition condition can be selected from the following three: (1) Flow rate ratio of SiH4:H2 is 1:10 - 1:50, (2) Flow rate ratio of SiH4:B2H6 is 1:0.0002 - 1:0.0003, and (3) Input power density is 0.1 W/sq. cm - 0.5 W/sq. cm. 4 figs., 2 tabs.

Sannomiya, H.

1996-11-22

367

Multi-frequency EDMR applied to microcrystalline thin-film silicon solar cells.  

UK PubMed Central (United Kingdom)

Pulsed multi-frequency electrically detected magnetic resonance (EDMR) at X-, Q- and W-Band (9.7, 34, and 94GHz) was applied to investigate paramagnetic centers in microcrystalline silicon thin-film solar cells under illumination. The EDMR spectra are decomposed into resonances of conduction band tail states (e states) and phosphorus donor states (P states) from the amorphous layer and localized states near the conduction band (CE states) in the microcrystalline layer. The e resonance has a symmetric profile at all three frequencies, whereas the CE resonance reveals an asymmetry especially at W-band. This is suggested to be due to a size distribution of Si crystallites in the microcrystalline material. A gain in spectral resolution for the e and CE resonances at high fields and frequencies demonstrates the advantages of high-field EDMR for investigating devices of disordered Si. The microwave frequency independence of the EDMR spectra indicates that a spin-dependent process independent of thermal spin-polarization is responsible for the EDMR signals observed at X-, Q- and W-band.

Meier C; Behrends J; Teutloff C; Astakhov O; Schnegg A; Lips K; Bittl R

2013-09-01

368

Plasmonic-photonic arrays with aperiodic spiral order for ultra-thin film solar cells.  

UK PubMed Central (United Kingdom)

We report on the design, fabrication and measurement of ultra-thin film Silicon On Insulator (SOI) Schottky photo-detector cells with nanostructured plasmonic arrays, demonstrating broadband enhanced photocurrent generation using aperiodic golden angle spiral geometry. Both golden angle spiral and periodic arrays of various center-to-center particle spacing were investigated to optimize the photocurrent enhancement. The primary photocurrent enhancement region is designed for the spectral range 600nm-950nm, where photon absorption in Si is inherently poor. We demonstrate that cells coupled to spiral arrays exhibit higher photocurrent enhancement compared to optimized periodic gratings structures. The findings are supported through coupled-dipole numerical simulations of radiation diagrams and finite difference time domain simulations of enhanced absorption in Si thin-films.

Trevino J; Forestiere C; Di Martino G; Yerci S; Priolo F; Dal Negro L

2012-05-01

369

Plasmonic-photonic arrays with aperiodic spiral order for ultra-thin film solar cells.  

Science.gov (United States)

We report on the design, fabrication and measurement of ultra-thin film Silicon On Insulator (SOI) Schottky photo-detector cells with nanostructured plasmonic arrays, demonstrating broadband enhanced photocurrent generation using aperiodic golden angle spiral geometry. Both golden angle spiral and periodic arrays of various center-to-center particle spacing were investigated to optimize the photocurrent enhancement. The primary photocurrent enhancement region is designed for the spectral range 600nm-950nm, where photon absorption in Si is inherently poor. We demonstrate that cells coupled to spiral arrays exhibit higher photocurrent enhancement compared to optimized periodic gratings structures. The findings are supported through coupled-dipole numerical simulations of radiation diagrams and finite difference time domain simulations of enhanced absorption in Si thin-films. PMID:22712091

Trevino, Jacob; Forestiere, Carlo; Di Martino, Giuliana; Yerci, Selcuk; Priolo, Francesco; Dal Negro, Luca

2012-05-01

370

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

Energy Technology Data Exchange (ETDEWEB)

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

Birkmire, R.W.; Phillips, J.E.; Buchanan, W.A.; Eser, E.; Hegedus, S.S.; McCandless, B.E.; Meyers, P.V.; Shafarman, W.N. [Univ. of Delaware, Newark, DE (United States)

1996-08-01

371

In situ monitoring the growth of thin-film ZnS/Zn (S,O) bilayer on Cu-chalcopyrite for high performance thin film solar cells  

International Nuclear Information System (INIS)

This paper highlights the crucial role that the control of the chemical bath deposition (CBD) process plays for buffer production of Cu-chalcopyrite solar-cell devices. ZnS/Zn (S,O) bilayer was deposited on CuInS2 (CIS) and Cu(In,Ga)(SSe)2 (CIGSSe) and monitored using turbidity measurements of the solution. The results were correlated to the X-ray photoemission spectra of the samples obtained by interruption of the process at sequential stages. Two different feature regimes were distinguished: In the first stage, a heterogeneous reaction takes place on the absorber resulting in the formation of pure ZnS. The second stage of the process is homogeneous, and the in-situ turbidity measurement shows a loss in the transmission of light through the CBD solution. The measured ZnL3M45M45 Auger-peaks, during this second stage of the process, show a shift of the kinetic energy from pure ZnS to a solid-solution ZnS/ZnO ('Zn (S,O)') with decreasing amount of sulfur. These results are supported by the observations from Energy-filtered transmission electron microscopy. This paper also demonstrates that monitoring of the CBD process combined with the basic understanding using surface and interface analysis have contributed to improve the reproducibility and to enhance the photovoltaic performance of Cu-chalcopyrite thin-film solar modules.

2009-02-02

372

Characterization of nanocrystalline SnO2 thin film fabricated by electrodeposition method for dye-sensitized solar cell application  

International Nuclear Information System (INIS)

[en]Nanocrystalline SnO2 thin film was prepared by cathodic electrodeposition-anodic oxidation and its structure was characterized by X-ray diffraction, SEM, UV-visible absorption and nitrogen adsorption-desorption by BET method. The obtained film has a surface area of 137.9 m2/g with grain sized of 24 nm. Thus the prepared SnO2 thin film can be applied as an electrode in dye-sensitized solar cell. The SnO2 electrode was successfully sensitized by Erythrosin dye and photoelectrochemical measurements indicate that the cell present short-circuit photocurrent (Jsc) of 760 ?A/cm2, fill factor (FF = 0.4), photovoltage (Voc = 0.21 V) and overall conversion efficiency (?) of 0.06% under direct sun light illumination. The relatively low fill factor and photovoltage are attributed to the reduction of triodiode by conduction band electrons and intrinsic properties of SnO2.

1351-01-00

373

Development of copper sulfide/cadmium sulfide thin-film solar cells  

Energy Technology Data Exchange (ETDEWEB)

The most important accomplishments during this period were to demonstrate and to elucidate further the complex effects that occur during the aging of Cu/sub 2/S/CdS thin-film solar cells in flowing wet oxygen. There are two distinct effects. At constant illumination, the short-circuit current of cells aged at room temperature consistently decreases with time. The second effect, related to diode opposing current, is more involved and may result from several competing mechanisms. Over the short term (approx. 4 to 5 hours), the magnitude of diode opposing current decreases. After approx. 20 hours of aging, opposing current generally returns to the level achieved after hydrogen annealing which immediately preceded the aging sequence. Optical measurements of the spectral transmission of the Cu/sub 2/S layers in a cell content have been made using a silicon detector epoxied to the back of a CdS cell after the copper foil substrate was removed. There is no significant change in Cu/sub 2/S transmission behavior for wavelengths ranging from 525 to 1000 nm during wet-oxygen aging for periods of 2 to 36 hours. This suggests that the decrease in J/sub SC/ at constant illumination, for the aging experiments in a flowing wet-oxygen ambient, arises because of changes in minority-carrier transport properties of the Cu/sub 2/S. Before developing a method for using an epoxied silicon detector to measure optical behavior of the Cu/sub 2/S layer, we explored the possibility of using a junction-containing wafer of silicon as a substrate for deposited CdS films. Some monolithic structures were successfully fabricated. Comparisons were made of CdS grain structure details in the junction detector area and in an adjacent metallized area.

Szedon, J. R.; Biter, W. J.; Dickey, H. C.

1982-03-08

374

Efficiency limitations of polycrystalline thin film solar cells: case of Cu(In,Ga)Se2  

International Nuclear Information System (INIS)

Small-area Cu(In,Ga)Se2 thin film solar cells have reached more than 19% efficiencies. Compared to other polycrystalline materials this efficiency value is remarkable. Nevertheless, the 19% for Cu(In,Ga)Se2 range more than 6% (absolute) below the world's best single-crystalline Si cells and almost 14% below the upper theoretical limit of 33% for an ideal black body cell with infinitely large mobility and radiative recombination only. About 4% out of the 14% are of optical nature, additional 3% stem from the limited mobility/diffusion length and from band gap fluctuations with a standard deviation no. sigmano. gno. approxno. 50 meV due to spatial variations of composition and stoichiometry of the quaternary compound Cu(In,Ga)Se2. Thus, about 26% efficiency would be possible if there were only these band gap fluctuations. Additional, voltage-dependent electrostatic potential fluctuations push down the efficiency further to 19%: The polycrystalline Cu(In,Ga)Se2 which is unavoidably structurally inhomogeneous due to dislocations, grain boundaries, point defects, etc. is also electrostatically inhomogeneous because of charged defects. Electrostatic potential fluctuations at the valence and conduction band edge may be not only responsible for a high saturation current density but also for the ideality factor in the current/voltage curve. The band gap and electrostatic potential fluctuations make the effective band gap which controls the intrinsic carrier density smaller than the average optical gap. The (zero bias) electrostatic potential fluctuations are here derived from the ideality factors of the current/voltage curve. The ideality factor reflects the voltage-induced electrostatic homogenization of the sample. For the world's best Cu(In,Ga)Se2 cells with an ideality factor of n id=1.5, we estimate zero bias electrostatic potential fluctuations with a standard deviation no. sigmano. elecno. approxno. 140 meV.

2005-06-01

375

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

International Nuclear Information System (INIS)

[en]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)

2002-06-27

376

Cu (In,Ga)Se{sub 2} thin films and solar cells prepared by selenization of metallic precursors  

Energy Technology Data Exchange (ETDEWEB)

CuIn{sub (1{minus}{ital x})}Ga{sub {ital x}}Se{sub 2} (CIGS) thin films with Ga ratio, {ital x}, ranging from 0.55 to 0.75 were grown on Mo/glass substrates by the selenization of metallic precursors in a H{sub 2}Se atmosphere. Without a postdeposition annealing step the films were found to have a highly graded composition that became Ga rich near the absorber/Mo interface. A high-temperature annealing step promoted diffusion of Ga to the surface region of the films. These absorbers were used to fabricate glass/Mo/CIGS/CdS/ZnO thin-film solar cells with open-circuit voltages ranging from 0.4 to 0.74 V and efficiencies approaching 12{percent}. Devices, as well as the absorber layers, were characterized. {copyright} {ital 1996 American Vacuum Society}

Basol, B.M.; Kapur, V.K.; Halani, A.; Leidholm, C.R. [International Solar Electric Technology, 8635 Aviation Boulevard, Inglewood, California 90301 (United States); Sharp, J.; Sites, J.R. [Physics Department, Colorado State University, Fort Collins, Colorado 80523 (United States); Swartzlander, A.; Matson, R.; Ullal, H. [National Renewable Energy Laboratory (NREL), 1617 Cole Boulevard, Golden, Colorado 80401 (United States)

1996-07-01

377

Cu (In,Ga)Se2 thin films and solar cells prepared by selenization of metallic precursors  

International Nuclear Information System (INIS)

CuIn(1-x)GaxSe2 (CIGS) thin films with Ga ratio, x, ranging from 0.55 to 0.75 were grown on Mo/glass substrates by the selenization of metallic precursors in a H2Se atmosphere. Without a postdeposition annealing step the films were found to have a highly graded composition that became Ga rich near the absorber/Mo interface. A high-temperature annealing step promoted diffusion of Ga to the surface region of the films. These absorbers were used to fabricate glass/Mo/CIGS/CdS/ZnO thin-film solar cells with open-circuit voltages ranging from 0.4 to 0.74 V and efficiencies approaching 12%. Devices, as well as the absorber layers, were characterized. copyright 1996 American Vacuum Society.

1996-01-01

378

Thin film solar cells based on the ternary compound Cu{sub 2}SnS{sub 3}  

Energy Technology Data Exchange (ETDEWEB)

Thin films of kesterite (Cu{sub 2}ZnSn(S/Se){sub 4}) semiconductors are considered promising absorber layer materials for low cost thin film photovoltaic devices. Experimental and theoretical investigations show, however, that the existence region of a single phase kesterite is relatively small making it difficult to grow single phase absorbers. The semiconducting compound Cu{sub 2}SnS{sub 3} is a common secondary phase that forms in Cu and Sn rich kesterite thin films during growth. Its appearance in a kesterite device would limit the V{sub OC} due to its smaller band gap. However, the band gap of about 1 eV, reported hole concentrations of 10{sup 18}cm{sup -3}, and an absorption coefficient in the visible region of 10{sup 5} cm{sup -1} make the Cu{sub 2}SnS{sub 3} compound itself a promising candidate for low cost photovoltaic applications. In this report we demonstrate the successful fabrication of a thin film solar cell based on Cu{sub 2}SnS{sub 3} via a precursor annealing process. The precursor is prepared by low cost electrodeposition. A maximum external quantum efficiency of about 60% at 800 nm and a band gap of 1.0 eV could be measured. To the best of our knowledge, there have been no other reports on the fabrication of Cu{sub 2}SnS{sub 3} based solar cell devices so far. Loss mechanisms and ways to increase efficiency are discussed.

Berg, Dominik M.; Dale, Phillip J.; Siebentritt, Susanne [University of Luxembourg, Laboratory for Photovoltaics, 41 rue du Brill, L-4422 Belvaux (Luxembourg)

2011-07-01

379

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

Energy Technology Data Exchange (ETDEWEB)

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)

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

2004-06-01

380

Thin Film Cell Development Workshop Report.  

Science.gov (United States)

The Thin Film Development Workshop provided an opportunity for those interested in space applications of thin film cells to debate several topics. The unique characteristics of thin film cells as well as a number of other issues were covered during the di...

J. R. Woodyard

1991-01-01

 
 
 
 
381

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)

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.

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

2012-06-25

382

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

International Nuclear Information System (INIS)

[en]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.

2012-06-25

383

Characterization of deep defects in CdS/CdTe thin film solar cells using deep level transient spectroscopy  

International Nuclear Information System (INIS)

The presence of deep defects in CdS/CdTe thin film solar cells strongly affects the electrical properties and as a result the performance of the cells. Therefore, it is desirable to understand the role of these defect states. This paper describes the detection of electron traps in CdS/CdTe thin film solar cells using deep level transient spectroscopy. Two series of samples with a different activation step (activation in air vs. activation in vacuum) are compared. Electrical injection DLTS uses an electrical pulse to inject electrons in the CdTe. This way a new electron trap could be characterized at 0.44 eV below conduction band in the air activated cells. Optical DLTS uses an optical laser pulse (?=635 nm) to create minority carriers. In this case minority traps are found in both kinds of samples. In the air activated cells two closely spaced defects are detected (0.44 and 0.42 eV below conduction band) with concentrations of a few percent of the background concentration. In the vacuum activated cells a broad band is detected. However, not fully characterized, it is located at approximately 0.4 eV below conduction band. Using the DLTS results, simulations were performed to explain the forward J-V-characteristics of the solar cells. These simulations are in close agreement with the experimental results if the concentrations of the deep traps are taken sufficiently high.

2004-03-22

384

Photoluminescence and time-resolved photoluminescence in Cu(In,Ga)Se2 thin films and solar cells  

International Nuclear Information System (INIS)

Photoluminescence (PL) and time-resolved PL (TR-PL) studies have been carried out on Cu(In,Ga)Se2 (CIGS) thin films and solar cells (ZnO/CdS/CIGS) to study the recombination of the photo-excited carriers. The CIGS solar cells exhibited intense near-band-edge (NBE) PL compared with the CIGS films by two orders of magnitude. PL decay time of the cell is strongly dependent on the repetition frequency of the excitation light. PL decay time of the cell is longer than that of the corresponding CIGS thin film. The chemical bath deposition of the CdS buffer layer on CIGS leads to changes in PL intensity, defect-related PL and the PL decay time. They are discussed with relation to the substitution of Cd atom at the Cu site at the Cu-deficient surface of CIGS thin film. Under the open circuit condition, NBE-PL is stronger and the decay time is longer compared with those under the short circuit condition. PL of the cell under the load was examined, and PL intensity and PL decay time are related to the photovoltage during PL measurements. Low temperature PL suggests that the Cd diffusion during the CBD process is pronounced for low Ga content CIGS. The authors demonstrate the effectiveness of PL as a powerful non-destructive device and photovoltaic characterization methods of CIGS solar cells. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

2009-01-01

385

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

2010-01-01

386

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

Energy Technology Data Exchange (ETDEWEB)

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)

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

387

Combined front diffraction and back blazed gratings to enhance broad band light harvesting in thin film solar cells  

Science.gov (United States)

Nanostructures with front dielectric and back metallic gratings in crystalline silicon (c-Si) thin film solar cells (TFSCs) are proposed. Different front and back gratings are designed. The diffraction effect of front dielectric gratings and surface plasmon polaritons (SPPs) enhancement induced by back metal gratings in the long wavelength range promote the total optical absorption. The simulation demonstrates that the dielectric and triangle metallic gratings have good performance. We achieve about 50 percent average optical absorption enhancement compared with the normal flat cells in a broad spectrum range from 300 to 1100 nm and 80 percent increase at the transverse magnetic (TM) polarized irradiation.

Zhang, Wei; Zheng, Gaige; Jiang, Liyong; Li, Xiangyin

2013-07-01

388

Preparation and characterization of CuInSe2 particles via the hydrothermal route for thin-film solar cells  

International Nuclear Information System (INIS)

Highlights: ? A new hydrothermal process for preparing copper indium diselenide (CuInSe2). ? Well-crystallized CuInSe2 particles are obtained at 180 deg. C for 1 h. ? Densified CuInSe2 thin films are prepared from ink printing. ? Increasing temperatures result in an improvement of properties of CuInSe2 films. - Abstract: CuInSe2 powders with a chalcopyrite structure used in thin-film solar cells were successfully prepared via a hydrothermal method at low temperatures within short durations. Well-crystallized CuInSe2 particles were formed via the hydrothermal reaction at 180 deg. C for 1 h. The concentrations of stabilizer, triethanolamine (TEA), significantly affected the purity, morphology and particle sizes of the prepared powders. Increasing the reaction duration and temperatures led to decrease the amount of second phase In(OH)3 and resulted in the formation of pure CuInSe2. Densified CuInSe2 thin films were prepared from ink printing with the addition of the flux. Increasing the selenization temperatures increased the grain size and improved the crystallinity of CuInSe2 films.

2011-05-12

389

Opto-electronic properties of rough LP-CVD ZnO:B for use as TCO in thin-film silicon solar cells  

International Nuclear Information System (INIS)

Polycrystalline Boron-doped ZnO films deposited by low pressure chemical vapor deposition technique are developed for their use as transparent contacts for thin-film silicon solar cells. The size of the columnar grains that constitute the ZnO films is related to their light scattering capability, which has a direct influence on the current generation in thin-film silicon solar cells. Furthermore, if the doping level of the ZnO films is kept below 1 x 1020 cm-3, the electron mobility can be drastically enhanced by growing large grains, and the free carrier absorption is reduced. All these considerations have been taken in account to develop ZnO films finely optimized for the fabrication of microcrystalline thin-film silicon solar cells. These TCO allow the achievement of solar cell conversion efficiencies close to 10%.

2007-10-15

390

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

Science.gov (United States)

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.

Fukano, Tatsuo; Tajima, Shin; Ito, Tadayoshi

2013-06-01

391

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

International Nuclear Information System (INIS)

[en]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.