Considering that our pv panel should be able to charge a 12v battery to its maximum voltage of about 14v and the overall electrical current voltage characteristic of the photovoltaic generator therefore. Cadmiumtelluridematerial for thin film solar cells. The melting point of cds is 1750 oc and of gaas is 1238 oc. Pdf simulation and performance study of nanowire cds. At the same time, cdte module efficiency increased from 9% to 18%. The institute of energy conversion iec has been involved in research and development of group iivi semiconductor thin film photovoltaic devices since its founding in 1972. Optimization of electrics parameters cdscdte thin film solar. Cadmium telluride cdte solar cells have quietly established themselves as a mass market pv technology. The solar cell current source generates a light current iph. Finally, the paper presents the way forward with next generation cdte based solar cells utilising lowcost materials in their columnar nature in graded bandgap structures. A range of the deposition parameters is included in table 1. Electronic properties of cdte cds solar cells as influenced by a buffer layer y. Solar cell market size, share industry report, 2022. Pv solar cells based on cdte represent the largest segment of commercial thinfilm module production worldwide.
Pv solar cells based on cdte represent the largest segment of commercial thinfilm. Semitransparent ultrathin cdte solar cells and durability. An overview of solar cell technology mike mcgehee materials science and engineering global climate and energy projectglobal climate and energy project center for advanced molecular photovoltaics precourt institute stanford university konarka nanosolar john benner provided the slides with the nrel logo. Cadmium telluride cdte is a stable crystalline compound formed from cadmium and tellurium. Chin department of physics, apollo solar energy research center. Optimization of electrics parameters cdscdte thin film. Cdte solar cells in substrate configuration cdte photovoltaics in the conventional configuration are a proven technology for the large scale production of lowcost currently below 0. Cost of power to be further reduced through performance increases and improvements in cell structure or processing. This design allows cdte solar cells to be made thinner and more. The fact that a variety of deposition technologies can be used to fabricate ef. Pdf high efficiency cdtecds thin film solar cell researchgate. Presented at the 2006 ieee 4th world conference on photovoltaic energy conversion wcpec4 held may 712, 2006 in waikoloa, hawaii.
For a device without cds layer, the reflectance spectrum indicates a bandgap of 1. Simulation of the efficiency of cdscdte tandem multi. Cadmium telluride cdte photovoltaics describes a photovoltaic pv technology that is based on the use of cadmium telluride, a thin semiconductor layer designed to absorb and convert sunlight into electricity. We have done modeling and simulation of thin film cds cdte solar cell and then used. 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. High efficiency solution processed sintered cdte nanocrystal. The leading thinfilm technology, cadmium telluride cdte, had a module production of 1. We see that cuingase 2 and cdte based solar cells have achieved efficiencies above those for asi cells. This structure achieved by rotating 90o in the base line structure that suggests high efficiency due to the high current density. The role of back buffer layers and absorber properties for. Thinfilm solar cells are finally becoming competitive. The efficiency of cdte solar cells has reached just more than 15 percent, and cigs solar cells have reached 20 percent efficiency.
The melting point of cdte is 1041 oc, and evaporation occurs at 1050 oc in open air and at about 900 c under nonoxidizing conditions. In addition to affecting the opencircuit voltage of a cell, it is commonly reported that buffer layers affect stressinduced degradation and transient phenomena in cdte and cuinse 2based solar cells. These cells produce lowcost electricity by absorbing sunlight at nearly the ideal wavelength. Optimum cell performance is usually found when the tco layer in contact with the cds is very resistive or almost insulating. There are health concerns with the use of cadmium in thinfilm solar cells. S1 supporting information the role of back buffer layers and absorber properties for 25% efficient cdte solar cells geethika k. Pdf a solar cell or photovoltaic cell is designed to convert sunlight into electrical energy through the photoelectric effect. Currently, first solar has announced a new world record this year for cdte pv solar cell efficiency of 17. Cadmium telluride cdte institute of energy conversion.
An electronic solar cell model can be considered, as shown in figure 5b, taking into account the effect of the series resistance rs and shunt resistance rsh. Rising penetration of renewable energy sources owing to environmental benefits coupled with increasing electricity demand is expected to propel market growth. The primary routes for increasing cds cdte solar cell efficiency involve increasing free carrier density, reducing bulk and interface recombination, andor reducing back contact barrier height. Solar cells of 79% efficiency were developed on sno x. A big step forward in cost reduction is expected through the growth of solar cells. Polycrystalline cdscdte solar cells al compaan distinguished university professor of physics, emeritus lecture for hebenellingson solar cells class mhmarch 15 201215, 2012 1. Cis started evaporating at 600 oc, but only a 20% weight loss was measured at oc steinberger, 1997. A solar cell is an electronic device which directly converts sunlight into electricity. Numerical simulation shows that the highest efficiency of singlejunction cdscdte solar cell equal to 18. Pdf simulation of cadmium telluride solar cells structure. 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. This is an important aspect to increase the specific power of cdte cds solar modules.
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 current. Cdte solar cell has been stagnant for the last few years. The best efficiency results reported for three of the more relevant thinfilm solar cell technologies are summarized in table 1 green et al. Life cycle impact analysis of cadmium in cdte pv production pdf. Thin film cds cdte solar cells has become one of the leading technologies for providing high power conversion efficiency at comparatively low manufacturing cost.
Cadmium telluride was originally considered for thin film solar cells because of its optimum band gap, high optical absorption coefficient and ability to be doped. In the article, we shall study the temperature and dopinglevel dependence of cdte solar cell performance including excitons with the modi. A high efficiency ultrathin cdte solar cell for nanoarea. Pv array made of cadmium telluride cdte solar panels type of solar power cell 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. The amount of cd in cdte solar cells is very small, and could be reduced even further as the cells become thinner. Design of a thin film cdte solar cell summary cadmium. In amorphous silicon solar cells, lightinduced degradation has a recoverable and a nonrecoverable component too, and the details of the. Thin film solar cells based on cdte cadmium telluride cadmium telluride is a material that is particularly well suited for thin film photovoltaics. As an absorber material for thinfilmbased solar cells, cdte holds the potentiality to fabricate highefficiency solar cells by means of lowcost technologies.
Cdte and cigs pv modules have the potential to reach. Pdf a solar cell is an electronic device which directly converts sunlight into electricity. Many of the topics that are discussed in this book are also covered in the massive open online course mooc on solar energy delftx, et. We have grown solar cells on 1 mm thick glass but they can also be grown on very thin 50100 m cover glasses while a low cost encapsulation or lamination can be applied to protect the back of the modules. Postdeposition processing options for highefficiency. Buffer layers are commonly used in the optimization of thinfilm solar cells. Cdte solar panel manufacturers thinfilm enf company. Small area laboratory devices have demonstrated ef. Due to their efficiency and relatively low manufacturing energy requirements, cdte solar cells had the shortest energy payback time among commercially relevant pv technologies. Czt is deposited by cosublimation of cdte and znte. Cadmium telluride solar cells photovoltaic research nrel. However, in the past decades, the opencircuit voltage has stagnated at around 800900 mv. Cdte solar panel manufacturers companies involved in cdte solar panel production, a key thinfilm panel technology.
Cdte thickness a cc b d normalizedcell performanceparameters of four differentcdte thickness solar cells. May 01, 20 the most common semiconductors used in thinfilm solar module production are amorphous silicon asi, cadmium telluride cdte, and copper indium gallium diselenide cigs. The result showed a considerable improvement over the 15% efficiency of the reference solar cell. The study is carried out by simulation with scaps solar cell capacitance simulator whose mathematical model is based on solving the equations of poisson and continuity of electrons and holes. Cadmium telluride cdte has long been recognized as a strong candidate for thin film solar cell applications. Pdf cdte solar cells with opencircuit voltage breaking. Manufacturing cdte solar cell is cheaper due to its significantly low raw material consumption. The different pv technologies are discussed in part iii. The layers succes sion and thicknesses are the one used in the present work. A cdscdte solar cell of greater than 1 cm2 area with an am1. The highest lab efficiency in thin film technology is 23. Concentrator solar cells expense of multijunction cell. Furthermore, thin film solar cells containing cadmium telluride hold a substantial advantage over conventional crystalline silicon solar cells.
Exploring back contact technology to increase cdscdte solar. High efficiency cdte and cigs thin film solar cells. Cadmiumtelluridematerial for thin film solar cells volume issue 10 dieter bonnet, peter meyers skip to main content accessibility help we use cookies to distinguish you from other users and to provide you with a better experience on our websites. Durose 1 1stephenson institute for renewable energy and department of physics, school of physical sciences, chadwick building, university of. Cds films have been prepared by chemical bath deposition and p. 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. Fcoated glass substrates with a lowtemperature cdte photovoltaic solar cells has been regaining momentum in recent years, due to commercial advances made with regard to cdte technology. Doping of polycrystalline cdte for highefficiency solar. Cdte thinfilm solar cells can be manufactured quickly and inexpensively, providing a lowercost alternative to conventional siliconbased technologies. Pdf cadmium telluride is a promising photovoltaic material for thinfilm solar cells. Chu introduces a front window layer reducing the thickness of. About 2,000 tons of cd is thrown away each year in the.
A study has been made to improve the efficiency of. Recognize the structure of cdte and cisg thin film cells as well as. In reality, siliconwafer cells achieve, on average, 15 to 25 percent efficiency. Potential of cdte thin film solar cells for space applications. Solar cell module efficiencies the record lab cell efficiency is 26. The solar cell cds cdte obtained in our model has an open circuit voltage of 775 v and a maximum power point of 645 mv. Global solar cell market size was estimated at 182. Study of efficiencies cdtecds photovoltaic solar cell. Cdte solar panels are now at parity with polycrystalline silicon for performance and cost. Cdte solar cell in a novel configuration tiwari 2004. Fabrication of cdscdtebased thin film solar cells using. Cadmium telluride pv is the only thin film technology with lower costs than conventional solar. Characterization of cadmium zinc telluride solar cells.
Leaching of cadmium and tellurium from cadmium telluride. The controlled doping of cdte with cu leads to increased hole density, enhanced carrier lifetime and improved carrier collection in the solar cell. Production method for cdte solar cells in substrate. Ion imppqgy p pglantation require energy to ionize the dopant. Fraunhofer institute for solar energy systems, ise with support of pse. Numerical modelling of accharacteristics of cdte and cis. Cadmium telluride solar cellscadmium telluride solar cells. The iiiv semiconductor compound, cdte, has suitable electrical and optical properties as photovoltaic and highenergy radiation sensor material. The cell was calibrated by the national renewable energy laboratorys measurements and characterizations facility. University of toledo old dominion university robert collins sylvain marsillac this program has explored a number of novel materials for contacts to cdte solar cells in order to reduce the back contact schottky barrier to zero and produce an ohmic contact. Postdeposition processing options for highefficiency sputtered cds cdte solar cells naba r. About 20,000 tons of cd are used worldwide each year, about half for nicd batteries.
For cuinse 2and cdte based solar cells, multilayer transparent conductors tcos, e. Simulation and performance study of nanowire cds cdte solar cell. Construct a band diagram of the cdscdte solar cell. It is mainly used as the semiconducting material in cadmium telluride photovoltaics and an infrared optical window. If all of it was used to make solar cells, we could generate 0. Numerical simulation shows that the highest efficiency of singlejunction cds cdte solar cell equal to 18. Solar photovoltaic pv cells san jose state university. Light soak stress of bare cdscds cdte cdte cells vs. Solar cells, covering single crystal, polycrystalline and amorphous materials utilising. Other inexpensive solar cells are emerging with high potential such as those based on cuinalse 2. A thinfilm solar cell is a second generation solar cell that is made by depositing one or more thin layers, or thin film tf of photovoltaic material on a substrate, such as glass, plastic or metal. The first thinfilm technology to be commercialized was amorphous silicon on glass, which was used to power small electronic devices such as calculators. A thin film solar cell is a second generation solar cell that is made by depositing one or more.
A novel structure of ultrathin cdte solar cells is proposed in this paper that focuses on conversion efficiency. How do buffer layers affect solar cell performance and solar. A screenprinted cds cdte solar cell was produced with improved preparation conditions for the carbon electrode, and the influence of the width of the cdte layer on the characteristics of the cell. Figure out the difference of mono and polycrystalline silicon solar cell. Cdte solar cells with opencircuit voltage breaking the 1 v. This letter describes the fabrication and characteristics of high. This paper focuses on the role of the back contact barrier in increasing cell efficiency.
It is usually sandwiched with cadmium sulfide to form a pn junction solar pv cell. After summarising the history of solar cells in chapter. Light shining on the solar cell produces both a current and a voltage to generate electric power. Cigs solar cell on a flexible plastic backing and rigid cdte panels mounted on a supporting structure. The cell was calibrated by the national renewable energy laboratorys. Our results offer new research directions for solving persistent challenges of cdte photovoltaics. This work involves characterization of cadmium zinc telluride films and solar cells prepared by close spaced sublimation. These devices could absorb uv, visible and ir radiation from the solar spectrum and combine impact. This process requires firstly, a material in which the absorption of light raises an electron to a higher energy state. The record efficiency for a laboratory cdte solar cell is 22.
High efficiency cdte and cigs thin film solar cells nrel. How do buffer layers affect solar cell performance and. 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. A simplified solar cell model and assumptions we consider a simpli. At the manufacturing front, the cdte technology is fast paced and moving forward with usbased first solar inc. Power conversion enhancement of cdscdte solar cell. The research on thin film cdte photovoltaic solar cells has been regaining momentum in recent years, due to commercial advances made with regard to cdte technology. Numerical modelling of accharacteristics of cdte and cis solar cells alex niemegeers and marc burgelman department of electronics and information systems elis, university of gent, gent, belgium. High efficiency solution processed sintered cdte nanocrystal solar cells. Performance cdte solar cells university of illinois angus rockett copis. Polycrystalline thinfilm cdtecds solar cells have been developed in a configuration in which a transparent conducting layer of indium tin oxide ito has been used for the first time as a back electrical contact on pcdte. Presented at the 2006 ieee 4th world conference on photovoltaic energy conversion wcpec4. 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. An overview of solar cell technology stanford university.
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