Jun 09, 2015 the development of cdte solar cells was initially motivated by their potential space application in communication satellites. Cdte thin film absorbers possess good electronic property favorable for solar cells action. Cadmium telluride cdte solar cells have quietly established themselves as a mass market pv technology. 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. With the data, we can save the variations of jsc, voc, ff and analyze the efficiency the jv characteristic modeled in figure 1 uses the values in table 1. The cell had an efficiency of 6%, but device instability caused by cu diffusion led to the. Primarily, the cdte thin film solar cell market has far exceeded industry expectations for growth and market volume and is poised for considerable growth in the coming years. Highefficiency thinfilm cdte solar cells can be fabricated using various methods ranging from the wet chemical techniques such as electrodeposition to the more conventional semiconductor processing methods such as vacuum evaporation. Preliminaries figure 1 shows schematic of ncdsp cdte solar cell devise structure used in the work, where h is the length of the cell, h e, the thickness of the emitter cds, h b the base cdte and w is the width of the depletion zone. Doping of polycrystalline cdte for highefficiency solar. Cadmium telluride solar cell an overview sciencedirect. Cadmium telluride pv is the only thin film technology with lower costs than conventional solar cells made of crystalline silicon in multikilowatt systems. May 31, 2006 recycling of cdte and cigs photovoltaic modules, 20th eurpvsec, barcelona, spain, june 610, 2005. Gallium arsenide gaas panels may be hazardous due to arsenic.
Several research works are going on to increase the efficiency of inorganic pv devices. Cadmium telluride solar cell an overview sciencedirect topics. Pdf quantum efficiency of cdte solar cells semantic scholar. Cdte photovoltaic devices for solar cell applications. Pdf processing options for cdte thin film solar cells. Some older silicon solar panels may be hazardous waste for hexavalent chromium coatings. Although the current record cdte solar cell efficiency is above 20%, it is still much lower than the maximum single junction theoretical efficiency of approximately 30%. Study of arsenic doped cdsete solar cells using transmission. In this paper we study cdscdte solar cells by means of amps1d software. They are believed to occupy most up to 48% of the solar cell production worldwide during 200819.
On a lifecycle basis, cdte pv has the smallest carbon footprint, lowest water use and shortest energy payback time of any current photo voltai. An overview of solar cell technology stanford university. J sc of over 25 ma cm 2 are achieved, which are comparable or higher than those achieved using traditional, closespace sublimated cdte. This effect shifts the qe of cdte cds cells to longer wavelengths with a few tens of nm. Mechanisms in cdte solar cells first annual report august 1998 august 1999 national renewable energy laboratory 1617 cole boulevard golden, colorado 8040393 nrel is a u. Due to the superstrate nature of cdte solar cells, the cdte layer is deposited on top of the cds layer, often at higher temperatures than at which the cds was deposited. Centre for diffraction data icdd pdf 2 powder diffraction file release 2004.
Flexible cdte solar cells of highest efficiencies of 12. High efficiency solution processed sintered cdte nanocrystal. Cdte based solar cells have shown promising increase in efficiency in the past few years. Cdte has been shown to be the most promising polycrystalline thin. About 2,000 tons of cd is thrown away each year in the. Jan 01, 2018 due to the superstrate nature of cdte solar cells, the cdte layer is deposited on top of the cds layer, often at higher temperatures than at which the cds was deposited. Solar cells made on a laboratory scale have reached efficiencies close to 22%, while modules made with fully automated inline machines show efficiencies above 18%. Cdte and cdsete cdte devices fabricated by closespace sublimation with a total absorber thickness of 1. The cds layer must therefore be stable enough to this recrystallization and intermixing so as to not disintegrate, but overall this intermixing process is beneficial to cell performance.
Now, record voltages of over 1 v have been reported in singlecrystal cdte heterostructure solar cells, which are close to those of benchmark gaas cells. In 1963, the first thin film solar cell of the type n cdte pcu2te was demonstrated by a general electric research laboratory 9. High efficiency cdte and cigs thin film solar cells nrel. Companies involved in cdte solar panel production, a key thinfilm panel technology. First we study the effect of thickness of semiconductor layers on the output. Cdte and cigs pv modules have the potential to reach cost effective pvgenerated electricity. Introduction in the past decade, cadmium telluride cdte solar cell technology has attracted great attention in the photovoltaic market due to its low cost and high efficiency,1,2. Current loss analysis shows that the cdsete layer is the primary absorber in the cdsete cdte structure, and fill factor loss analysis shows that. Cdte solar panels may be a hazardous due to cadmium. The schematics of cds cdte solar cell is shown in fig 1. Aug, 20 the controlled doping of cdte has enabled the achievement of efficiencies up to.
Pdf quantum efficiency of cdte solar cells semantic. Midgap trap states in cdte nanoparticle solar cells. Institute of photovoltaics, university of stuttgart, germany. Cdte solar cell, efficiency, reverse saturation current, temperature effect. Overcoming degradation mechanisms in cdte solar cells. The majority of these emissions 77% result from mining. Simulation of the efficiency of cdscdte tandem multi. Solar cell devices were formed with 60nm of aluminum thermally evaporated on the cdte to form a schottky junction at the back contact. Maximize cdte solar cell performance through copper. Yet the record laboratory efficiencies of cdte based solar cells 22% are still well below their theoretical efficiency limit of 30%. This article describes the latest information achievement in the field.
A solar panel converts the suns radiant energy into electricity using photovoltaic cells commonly known as solar cells. 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. Life cycle impact analysis of cadmium in cdte pv production pdf. Cdte thin film solar cell market research report 20212026 the global cdte thin film solar cell market is the focus of rapid innovation and exquisite competition. The schottky barrier cdte solar cells had power conversion ef. Characterization of thin cdte solar cells with a cdsete. Institute of photovoltaics, university of stuttgart, germany the 21st. The bandgap egx of the mixed phases has a minimum value 1.
Cdte thin film solar cell structure comprises of a ptype cdte absorber layer and ntype cds based window layer forming a heterojunction, which has an intermixed interface region. The efficiency of the commercial cdte solar module is about 8% for 55 w modules first solar, 2004. The invention discloses a kind of cdte thinfilm solar cells preparation method, the cdte film adopts the near space sublimed method to prepare the cds cdte battery on transparent conducting glass, and the ni back electrode adopts magnetron sputtering to obtain, and at first carries out the transparent glass substrate preliminary treatment. Department of energy laboratory operated by midwest research institute battelle bechtel contract no. Thin film solar cells a thin film of semiconductor is deposited by low cost methods.
The material is used for solar cells photovoltaics, detectors, nanoinks, and nanorods. Cadmium telluride cdte photovoltaics describes a photovoltaic pv technology that is based. Cdte solar panel manufacturers thinfilm enf company. Schematics of a typical superstrate cds cdte solar cell structure the typical superstrate structure of a cdte cds solar cell is composed of four layers as follows. Despite the market remaining dominated by silicon, cdte now accounts for around a 7% market share 1 and is the first of the second generation thin film technologies to effectively make the leap to truly mass deployment. Pdf cdtecds solar cells on flexible substrates joel. Feb 29, 2016 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. About 20,000 tons of cd are used worldwide each year, about half for nicd batteries.
Using nznop cdte as a model system, we fabricate sintered cdte nanocrystal solar cells processed at 350 c with power conversion efficiencies pce as high as 12. Fabrication and characterization of single crystal cdte. Optimization of electrics parameters cdscdte thin film solar. It is mainly used as the semiconducting material in cadmium telluride photovoltaics and an infrared optical window. Cadmium telluride photovoltaics describes a photovoltaic technology that is based on the use of cadmium telluride in a thin semiconductor layer designed to absorb and convert sunlight into electricity. The efficiency of the cdte cds solar cell reached 21. Solar cell materials are chosen largely on the basis of how well. It is usually sandwiched with cadmium sulfide to form a pn junction solar pv cell.
Cdte and cigs pv modules have the potential to reach cost effective pv generated electricity. Solar cells are a promising and potentially important technology and are the future of sustainable energy for the human civilization. A transparent and conducting oxide tco which acts as a front contact 2. Fabrication of cdtesi heterojunction solar cell springerlink. This chapter serves as an overall introduction to cdte solar cells, beginning. Kimbis, solar energy technology program, us depart ment of energy, 2011, pdfssolar program mypp 20082012. Cdte has been shown to be the most promising polycrystalline thin film material for producing pv solar cells because of its high absorption coefficient. These include the relationship between bandgap and ef.
Laser scribing was used for patterning of layers and. Measurement of the cdte minority carrier recombination lifetimes. Cdte solar cells solar cell request pdf researchgate. Cpa choosing to purchase solar modules that contain toxic metalscurrent cdte panels result in cd gaseous emissions of 0. Study on the stability of unpackaged cdscdte solar cells. Characterization of thin cdte solar cells with a cdsete front. Cdte solar cells with opencircuit voltage breaking the 1. Solar cells are also fabricated from other semiconductor materials such as gaas, gainp, cuingase 2, and cdte, to name but a few. After sintering for greater than 1min the thickness of the. Even though considerable effort has been spared to optimize the fabrication technology of cdte solar cells, efficiencies of small area cdte solar cells have stagnated at 1516. Light characteristics of cdte solar cells were carried out by using a solar cell tester gsola xjcm9 under am1. Cells can be flexible and integrated directly into roofing material. They have transitioned from the laboratory to the market place.
This efficiency is comparable wit h that of the best crystalline silcon solar cells. History of cdte solar cells everything about solar energy. When the quantum efficiency of a cds cdte solar cell is measured under forward voltage, the measurement is likely affected by several factors including 1 the voltage dependence of the collection efficiency, 2 series resistance of the cell and instrumentation, 3 the electrical barrier of the back contact, 4 photoconductive effects in the cds and cdte, and 5 any secondary barrier in. Within each solar cell are semiconductors that perform an. The history of photovoltaics with emphasis on cdte solar. The article also contains data related to the worlds energy and particularly that part which related to the conversion of solar energy into electrical energy. The amount of cd in cdte solar cells is very small, and could be reduced even further as the cells become thinner. An examination of these different methods reveals that there are similarities between the postdeposition treatments that the cdte films are subjected to, before. Cdte thin film solar cell market by manufacturers, regions.
Moreover, the impressive recent efficiency gains are. Among thinfilm photovoltaic technology, cadmium telluride cdte has achieved a truly impressive development that can commercially compete with silicon, which is still the king of the market. Cadmium telluride cdte has long been recognized as a strong candidate for thin film solar cell applications. Recent developments of flexible cdte solar cells on metallic. In conventional cdte solar cells, glass makes up to 98% of the device thickness and weight. The solar cell is the first building block of a solar panel. As an absorber material for thinfilmbased solar cells, cdte holds the potentiality to fabricate highefficiency solar cells by means of lowcost technologies. Conventional cdte solar cells have been fabricated on glass substrate using up to 14 methodologies, with css giving the highest efficiency of 17. Key ingredients in a solar panel include solar cells, photovoltaic modules, and semiconductors.
Cn101609860a cdte thinfilm solar cells preparation. Fabricate cdte pn homojunctions and characterize them with iv and cv. Department of energy laboratory operated by midwest research institute battelle. Recent developments of flexible cdte solar cells on. The cdte cds solar cell has reached an efficiency of 22. Cdte and the rta process is a viable approach to engineer the cu distribution in cdte solar cells. Cdte solar cells with opencircuit voltage breaking the 1 v. First solar cdte pv modules technology overview and energy. The iiiv semiconductor compound, cdte, has suitable electrical and optical properties as photovoltaic and highenergy radiation sensor material. The greatest challenge faced by cdte researchers is the fact that the cdte cell components and fabrication processes have significant interdependencies and cannot be easily decoupled. Cdte as one of the iivi semiconductors has become attractive over the last few decades as a result of commercial applications in thinfilm solar photovoltaic technology. From the early days of photovoltaics until today, thinfilm solar cells have always competed with.
Cadmium telluride cdte is a stable crystalline compound formed from cadmium and tellurium. Paper open access related content impacts of temperature on. Fabrication and characterization of single crystal cdte solar. Study of efficiencies cdtecds photovoltaic solar cell. Here, the performance of cdte solar cells cheaper alternatives to silicon photovoltaics is hampered by their low output voltages, which are normally well below the theoretical limit. However, there is something which has not been completely clarified. Moreover, the rate of change in performance parameters due to temperature are also measured and compared with the results available in the earlier published works. A range of the deposition parameters is included in table 1. Abstract design strategies for highefficiency cdte solar cells with continuous technology advances over the past years, cdte solar cells have surged to be a leading contributor in thin. Pdf cadmium telluride cdte is the most commercially successful thinfilm photovoltaic technology. In this work, the stability of unpackaged cdte solar cells with different configurations was investigated according to the international electrotechnical commission iec 612152016. Window layerfor superstrate thin film cdte solar cells, the window layer is broadly defined as all the layers through which light passes before being absorbed in the cdte, and the glass superstrate. Deposition techniques are briefly described, results of present pilotline production efforts and the future potential are discussed, which make the cdte thin film solar cell a promising candidate for low cost and wellabove 10% moduleefficiency. This leads to recrystallization of the cds and intermixing of the cds and cdte layers to form cds 1.
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