Development of cdte as a solar cell material dates. Development of cdte thin film solar cells on flexible foil substrates deidra ranel hodges university of south florida follow this and additional works at. Polycrystalline cdscdte solar cells al compaan distinguished university professor of physics, emeritus lecture for hebenellingson solar cells class. Introduction fighting climate change demands a boost in. Graphic showing the five layers that comprise cdte solar cells. Doping of polycrystalline cdte for highefficiency solar.
On a lifecycle basis, cdte pv has the smallest carbon footprint, lowest water use and shortest energy payback time of any current photo voltaic technology. Kodak introduces close spaced sublimation method 1991. After annealing treatment, the cdte solar cells were prepared. Cdte solar cells are the second most common photovoltaic pv technology in the world marketplace after crystalline silicon, currently representing 5% of the world market. Conference proceedings papers presentations journals. The free carrier absorption in the infrared is less important for cdte because of its higher gap with respect to, for example, cigse or. Pv solar cells based on cdte represent the largest segment of commercial thin.
Cadmium telluride cdte photovoltaics or also called cadmium telluride solar cell is a kind of photovoltaic pv technology that can produce electricity from sunlight using a thinfilm of compound cadmium telluride to absorb and convert sunlight into electricity. Pdf cadmium telluride cdte is the most commercially successful. Correspondingly, the results have demonstrated that performance of. Effects of cdcl2 treatment on physical properties of cdtecds. Thermal evaporation is able to produce a pinhole free. A solar cell is an electronic device which directly converts sunlight into electricity. Study of thin film polycrystalline cdte solar cells.
A range of the deposition parameters is included in table 1. Wiringup carbon single wall nanotubes to polycrystalline. Enf industry directory solar world map solar news newsletter. Durose 1 1stephenson institute for renewable energy and department of physics, school of physical sciences, chadwick building, university of. Cdte solar panel manufacturers companies involved in cdte solar panel production, a key thinfilm panel technology. Development of cdte thin film solar cells on flexible foil.
Although the fundamental limits have been established for the single junction solar cells, tandem configurations are one of the promising approaches to surpass these limits. This was achieved by varying the cdte thickness by chemically bevelling the cells in a br2methanol solution. Among all kinds of semiconductor materials, cds exhibits the lowest lattice mismatch with cdte, which permits high junction quality and high device performance. Design of a thin film cdte solar cell summary cadmium. The impact of interstitial fe contamination on ntype. Electronic properties of cdscdte solar cells as influenced.
High efficiency solution processed sintered cdte nanocrystal. Electronic properties of cdte cds solar cells as influenced by a buffer layer y. Cadmium telluride cdte photovoltaics solarfeeds marketplace. Light photon energy electric energy silicon solar photovoltaic cells a device made of semiconductor materials that produce electricity under light a pn junction is created in silicon by a doping process. Chu introduces a front window layer reducing the thickness of cds 15% efficiency. Apr 04, 2016 cdcl2 activation step cdcl2 activation is vital to high efficiency cdte solar cells typically converts a cell of 10% a thin layer 20200nm of cdcl2 is deposited on the cdte free back surface sample then annealed in a tube furnace under an air ambient can also be done with mgcl2 as an alternative. Thin film cdte solar cells have recently reached 22. Effects of cdcl2 treatment on physical properties of cdte.
Thin film cds cdte has long been regarded as one promising choice for the development of costeffective and reliable solar cells. Degradation of ultrathin cdte films with swcnt or graphene back contact. Cadmium telluride cdte thin film solar cells are known for their fastest energy payback time of all solar technologies. Electronic properties of cdtecds solar cells as influenced by a buffer layer y. However, although the thin films are more compact and free of micropores. Cadmium telluride solar cells photovoltaic research nrel. Cadmium telluride cdte is a stable crystalline compound formed from cadmium and tellurium. The chloride annealing for back contact layer free cdte. The world leader in ii vi material technology and innovation. The lowresistance behavior of back contact is attributed to the high work function of moo x, which reportedly is as high as 6. Cdte solar cells with opencircuit voltage breaking the 1.
The large area cdte thin film samples were used for chloride annealing. Most of the thin film solar cells and asi are second generation solar cells, and are more economical as compared to the first generation silicon wafer solar cells. Key aspects of cdtecds solar cells durose 2002 physica. The nearly ideal shortcircuit current density j sc achieved with the record device 31.
This design allows cdte solar cells to be made thinner and more. First solars cdte module technology performance, life. In this study, high quality cds nanocrystals were prepared by a. Solutionprocessed cdte nanocrystals solar cells have attracted much attention due to their low cost, low material consumption, and potential for rolltoroll production. First solar sets world record for cdte solar cell efficiency. Numerical modeling of a cdscdte photovoltaic cell based on znte. Siliconwafer cells have light absorbing layers up to 350 m thick, while thinfilm solar cells have a very thin light absorbing layers, generally of the order of 1 m thickness. Cdte solar panel manufacturers thinfilm enf company. New materials for thin film solar cells intechopen. Copper doping of cdte assists in forming back contacts to cdte devices in both laboratory studies and commercial applications, but cu is known to di. Cdcl2 activation step cdcl2 activation is vital to high efficiency cdte solar cells typically converts a cell of 10% a thin layer 20200nm of cdcl2 is deposited on the cdte free back surface sample then annealed in a tube furnace under an air ambient can also be done with mgcl2 as an alternative. Studies of basic electronic properties of cdtebased solar cells. Pv solar cells based on cdte represent the largest segment of commercial thinfilm module production worldwide. First solar set a world record for cadmiumtelluride cdte photovoltaic pv solar cell conversion efficiency, achieving 20.
Due to its basic optical, electronic, and chemical properties, cdte can become the base material for highefficiency, lowcost thin film solar cells using robust, highthroughput manufacturing techniques. It is mainly used as the semiconducting material in cadmium telluride photovoltaics and an infrared optical window. The solid semiconductor compound cdte is a crystalline, nonflammable. One compelling solutionbased processing strategy utilizes semiconductor layers produced by sintering nanocrystals into largegrain semiconductors at relatively low temperatures. Highefficiency ctoztocdscdte polycrystalline thinfilm solar. Czt is deposited by cosublimation of cdte and znte. Cadmium telluride cdte photovoltaics describes a photovoltaic pv technology that is based on the use of cadmium telluride in a thin semiconductor layer designed to absorb and convert sunlight into electricity. Thus, we provide a critical overview of the current research and an outlook of the paths toward lead free perovskite solar cells. In the present work, effects of cdcl 2 thermal treatment on physical properties of cdtecds heterojunction solar cells, fabricated using css and cbd, have been investigated.
Cadmium free high efficiency cu2znsns, se4 solar cell. The cucl2nh4cl solution was attached on the cdte surface. Simulation of the efficiency of cdscdte tandem multi. It has been shown by various groups that ternary compounds form as a result of interdiffusion between cdte and cds. Due to its basic optical, electronic, and chemical properties, cdte can become the base material for highefficiency, lowcost thin film solar cells using robust, high. This work involves characterization of cadmium zinc telluride films and solar cells prepared by close spaced sublimation. Solutionprocessed efficient nanocrystal solar cells based on. For example, copper cu was initially believed to be a key element for the formation of the back contact, until studies of impurity distribution in cdte cds solar cells indicated that this element accumulates at the. Pdf a solar cell is an electronic device which directly converts sunlight into electricity.
Iron pyrite nanocrystal film serves as a copper free back contact for polycrystalline cdte thin film solar cells. Despite the market remaining dominated by silicon, cdte now accounts for around a 7% market share and is the first of the second generation thin film technologies to effectively make the leap to truly mass deployment. Working principle of silicon solar pv cells photovoltaic material of device converts. This paper presents a simple study investigating cadmium telluride solar cells structure by. Cdte thinfilm solar cells can be manufactured quickly and inexpensively, providing a lowercost alternative to conventional siliconbased technologies. The impact of interstitial fe contamination on ntype czsilicon for high efficiency solar cells. Advanced photonics journal of applied remote sensing. Pdf cdte solar cells with opencircuit voltage breaking the. Characterization of cadmium zinc telluride solar cells. Cadmium telluride cdte solar cells have quietly established themselves as a mass market pv technology. Thermal evaporation is able to produce a pin hole free. The best performance was obtained at a cdte thickness of 3.
Pdf a solar cell or photovoltaic cell is designed to convert sunlight into electrical energy. Depending on the processing technology solar cells are of various types. Using nznopcdte as a model system, we fabricate sintered cdte nanocrystal solar cells processed at 350 c with power conversion efficiencies pce as high as 12. The record efficiency for a laboratory cdte solar cell is 22. After summarising the history of solar cells in chapter. One of the candidates for the top cell absorber is cdte, as the cdte photovoltaic technology has significant advantages. A student introduction to solar energy edx free online. Government and mri retain a nonexclusive royaltyfree license to publish or reproduce the published. About a year ago, first solar crushed the conversion efficiency mark for cadmium telluride with a worldrecord 21.
Raw material, manufacturing, operation and decommissioning stages of cdte cells typically produce two orders of magnitude less cadmium emissions to the environment compared to coalii burning power plants. Solar energy materials and solar cells 2015, 140, 108114. Cdte solar cells with opencircuit voltage breaking the 1 v. Polycrystalline cdscdte solar cells al compaan distinguished university professor of physics, emeritus lecture for hebenellingson solar cells class mhmarch 15 201215, 2012 1. Solutionprocessed efficient nanocrystal solar cells based. One such application is search of new materials for thin film solar cells as it provides the solution for the todays concern of energy crisis. A lowresistance back contact for ncdspcdte solar cells has been developed, which utilizes a thermally evaporated moo x thin film as the buffer layer between the pcdte and the back electrode. Cdte solar cells have the potential to undercut the costs of electricity generated by other technologies, if the opencircuit voltage can be increased beyond 1 v without significant decreases in. Moox as an efficient and stable back contact buffer for. Department of energys national renewable energy laboratory nrel the recordsetting cell was constructed at the. Annealing of the cdstco transparent conductive oxide bilayer in both oxidising and reducing ambients was investigated in order to study changes in the electrical properties of the incds. Among them, silicon wafer solar cells and thin film solar cells are most promising. Cadmium telluride was originally considered for thin film solar cells because of its. Cadmium telluride pv is the only thin film technology with lower costs than conventional solar cells made of crystalline silicon in multikilowatt systems.
Short production cycle and high absorption efficiency at low light and high temperature makes this technology a good choice for solar power plants. This thesis presents various studies into the effects of both growth and processing conditions on a the electrical properties of interfaces of the cdte solar cell, and b the photovoltaic pv performance. Cdte is an exceptional technology to invest in today, with projected efficiencies expected to soon rival silicon modules, but at far lower capital and production costs. It is usually sandwiched with cadmium sulfide to form a pn junction solar pv cell. Ctf solar designs and constructs cdte solar module production facilities including factory buildings, production lines, and all the necessary equipment and services.
Introduction over the last two decades, polycrystalline thinf ilm cdscdte solar cells fabricated on glass substrates have been considered as one of the most promising candidates for largescale. Cadmiumtelluridematerial for thin film solar cells. Thin film cdte solar cells are typically heterojunctions, with cadmium sulfide cds. Pdf simulation of cadmium telluride solar cells structure. Cdte solar cells and modules have been manufactured on polyimide pi substrates. One of the major challenges of cdte solar cell research is the. As a comparison, typical commercial siliconbased solar cells require an absorber thickness of around 200 mm whereas their cdte equivalents are less than 5 mm thick. The united states is the leader in cadmium telluride cdte photovoltaic pv manufacturing, and nrel has been at the forefront of research and development in this area.
The structure of the thin films and the properties of the cdte solar cells were tested for studying the effect of the ratio of cucl, solution concentration and the annealing temperature. Nominally identical solar cells fabricated using 99. Pdf cdte solar cells with opencircuit voltage breaking. Materials free fulltext combined opticalelectrical.
Cdte solar panels are now at parity with polycrystalline silicon for performance and cost. Efficiency of thinfilm cdscdte solar cells leonid kosyachenko chernivtsi national university ukraine 1. Superstrate the superstrate configuration is used in most cdte solar cells this is due to the particular difficulty in making the rear contact we will see why the back contact is usually deposited at the end of the cell to have a better control superstrate configuration. Al was used as a transparent conductive oxide tco front contact, while a thin high resistive transparent layer of intrinsic zinc oxide izno. Durose 1 1stephenson institute for renewable energy and department of physics, school of physical. Part of the american studies commons scholar commons citation hodges, deidra ranel, development of cdte thin film solar cells on flexible foil substrates. Both the uniformity and roughness of the cell layers are vital to obtaining high quality results using this methodology. This process requires firstly, a material in which the absorption of light raises an electron to a higher energy state. Light shining on the solar cell produces both a current and a voltage to generate electric power.
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