Properties of solar cells fabricated with and without an undoped zno layer were compared. In this final report highlights of the first three quarters will be provided and details will be given of the final quarter of the subcontract. Deposition and characterization of cu2znsns4 thin films. Champion efficiency of czts thin film solar cell tfsc has reached 8. Towards highefficiency czts solar cell through buffer. Defect and heterojunction engineering in czts solar cells by. Cu2znsns4 thin film solar cells by fast coevaporation. Defect and heterojunction engineering in czts solar cells.
Cu2znsns4 czts based solar cells show a promising performance in the field of sunlightbased energy production system. Solar cell performance was evaluated under standard conditions with an irradiation of 100 mwcm 2. Nontoxic and cheap thinfilm solar cells for zeroenergy buildings. In this work, numerical simulations were performed on structures based on czts absorber layer, zno window layer, and transparent conducting layer nito with different buffer. Fundamental properties of solar cells, principles and. At last, the development prospect of cu2znsns4 thin film solar cells was. After discussing some basics from electrodynamics in chapter 4 and solar radiation in chapter 5, we spend several. This improvement is attributed to the better charge collection, which may.
It is a wellknown fact that modern society consumes a lot of energy, and at a rapidly increasing pace. Socalled thinfilm solar panels, although less efficient per square meter, tend to be much cheaper to produce, and they are the technology being tapped to realize the worlds largest proposed pv plant, the rancho cielo solar farm in belen, n. Czts was first created in 1966 and was later shown to exhibit the photovoltaic effect in 1988. All constituents of this czts film, which are abundant in the crust of the earth. Pdf earthabundant and lowcost czts solar cell on flexible. If all of it was used to make solar cells, we could generate 0. Analysis of sns2 buffer layer and sns back surface layer. Scientists at swansea university in wales uk have shown that cu2znsns,se4 czts, which is based on earthabundant elements, could potentially be an alternative to conventional cuin,gase2 cigs in solar cells cztsbased solar cells are currently much less efficient than cigs devises12. Properties of high efficiency cigs thinfilm solar cells. Figure 11 shows the jv curve of czts solar cells and the area was 0. Improvement of mocu2znsns4 interface for cu2znsns4 czts. Jan 10, 2018 the czts ns exhibits superior photoelectrochemical activity as compared to zerodimensional czts nanospheres and comparable performance to pt counter electrode for dye sensitized solar cells. Screening of suitable cationic dopants for solar absorber.
They have been recognized as a promising alternative to current solar cells because of their high absorption efficiency, direct band gap around 1. Experimental study of cu2znsns4 thin films for solar cells. A wellperforming czts zto device with antireflective coating yielded an efficiency of 9. Czts cells are thinfilm solar cells that work as a result of the photoelectric effect 4. The spray solutions were prepared with different molar concentrations of copper. Synthesis of czts nanocrystals polycondensation reactions at 200 c were performed in ethylene glycol, ethanol and isopropanol using cucl2 xh2o. Apr 16, 2019 a high open circuit voltage of 809 mv is obtained for an ordered czts absorber with cds buffer layer, while a 9.
An overview of solar cell technology stanford university. Beyond 11% efficient sulfide kesterite cu2znxcd1xsns4. Introduction currently, absorber materials in thin. Highest laboratory efficiency reported till date is 12. Three methods have been investigated including a thin ag coating, a thin zno coating on the mo back contact and rapid thermal annealing of the back contact. Currently, it accounts for around 20% of the pv market. Recently, research in this area has gained momentum due to the desirability of producing ga, in and cd free absorber layers and the potential to. With the goal to obtain different band alignments, these czts absorbers are combined with zn 1. These elements are available in the earths crust as. Optical and electrical properties study of solgel derived.
We report the performance of cu2znsns4 czts thin film solar cell that showed efficiency in the range of 6. Czts has kesterite structure and the compositions formula is cu 2 znsnsse 4. Towards highefficiency czts solar cell through buffer layer. The cztsns exhibits superior photoelectrochemical activity as compared to zerodimensional czts nanospheres and comparable performance to pt counter electrode for dye sensitized solar cells. Czts thin film solar cells institute for materials. Enhanced heterojunction interface quality to achieve 9. This paper summerized the development situation of cu 2 znsns 4 thin film solar cells and the manufacturing technologies, as well as problems in the manufacturing process. Characterization of a czts thin film solar cell grown by sputtering. Experimental study of cu2znsns4 thin films for solar cells hendrik flammersberger cu2znsns4 czts is a semiconductor with a direct band gap of about 1,5 ev and an absorption coefficient of 104 cm1, and is for this reason a potential thin film solar cell material. Pdf b flexible cu 2 znsns 4 czts solar cell absorbers were. A student introduction to solar energy edx free online. Current challenges and future prospects for a highly. A cadmiumfree cu2znsns4zno heterojunction solar cell.
But vacuum lines were still unable to avoid expensive equipment. Sputtering of precursors for cu2znsns solar cells and. A wellperforming cztszto device with antireflective coating yielded an efficiency of 9. Liquid junction solar cells abstract copperzinctinsul. The increase of grain size decreases the grain boundaries that diminish recombination and thereby the effective diffusion length of the minority carriers is increased causing a higher short circuit photocurrent in polycrystalline solar cells 15. The main advantage for cigs solar cells is the high efficiency, which has. The best performing devices are produced with a very rapid 1 min sulfurization, resulting in very small grains. May 06, 20 free and the studys lead author, prashant sarswat, a research associate in metallurgical engineering, are publishing their study of the microwaved photovoltaic semiconductor known as czts for. Highefficient cd free czts solar cells achieved by nanoscale atomic layer deposited aluminium oxide. Ito and nakazawa at shinshu university succeeded in fabricating the czts thin film by the atomic beam sputtering technique, and clarified that the optical band gap energy was near the optimum value of 1. In this work, numerical simulations were performed on structures based on czts absorber layer, zno window layer, and transparent conducting. This improvement is attributed to the better charge. Solar cell devices made from these czts layers show the currently highest device performance of czts based thin film solar cells fabricated by a fast coevaporation process with a maximum efficiency of 4. Solutionprocessed cdsubstituted czts photocathode for.
The focus of this work is on back contact improvement for sputtered czts thin film solar cells. In search of lower cost cells, people began experimenting with different liquid nonvacuum deposition methods in the recent two years and achieved a conversion efficiency of 11. Study of czts and cztsse solar cells for buffer layers selection authors. The thin film solar cell technology is growing in both capacity and market share. Cu 2znsns 4 czts, having the kesterite structure, is one of the most promising absorber layer candidates for low cost thin film solar cells, because of its suitable direct band gap between 1. Solar frontier breaks czts cell efficiency record pv.
Raman mapping analysis to improve czts solar cells solar. Cu 2 znsns 4 is considered as the ideal absorption layer material in next generation thin film solar cells due to the abundant component elements in the crust being nontoxic and environmentally friendly. Surfactantfree czts nanoparticles as building blocks for low. Development of cztsbased thin film solar cells sciencedirect. The efficiency decreased with the decrease of the ration of zn to sn for cdbased czts solar cell. Cdte solar cells account for about 10% and the remainder is divided between thin film silicon and cuin,gase 2 cigs where cigs is growing rapidly. Demonstrated efficiencies of up to 6,8% as well as use of cheap and. 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. Influence of reaction conditions on the properties of. Indepth characterization of secondary phases in cu2znsns4.
Therefore, pv systems can work continuously free from maintenance longer than. 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. Larger grains are required to fabricate high efficiency solar cells. However, the contrary was true for cd free czts solar cell. Part ii aims to cover all the physical fundamentals that are required for understanding solar cells in general and the different technologies in particular. Fabrication of efficient cu2znsns4 solar cells by sputtering. Cu2znsns4 czts is one of the most promising thin film solar cell absorber. Development of rare metalfree cztsbased thin film solar cells. Aug 26, 2015 the commonly observed ptype conductivity of czts thin films comes mainly from the cuzn antisite defect, partly explaining why czts thin films must be cupoor and zinc rich to successfully fabricate czts solar cells. Kesterite cu2znsns4 czts thinfilm solar cells have drawn worldwide attention because of outstanding performance and earthabundant constituents. Czts, photovoltaics, composition, wurtzite, kesterite 1. Us9112075b2 cigs or cztsbased film solar cells and. Znozns or znse czts coreshell vertically aligned nanorods array is reported. Czts also has near ideal properties for solar photovoltaics, as it is a very strong absorber and has a band gap of around 1.
Unsw takes out czts efficiency world record pv magazine. Cu2znsns4 cztsbased solar cells show a promising performance in the field of sunlightbased energy production system. Worlds highest efficiency rating achieved for czts thinfilm solar cells. Solar frontier announced on tuesday that it had set a new conversion efficiency record for czts solar cells measuring 0. Cu2znsns4 czts is a promising candidate material for photovoltaic applications. To increase the performance of czts based solar cell, buffer layer optimization is still an obstacle. Study of czts and cztsse solar cells for buffer layers. Hereafter the czts had aroused the latent commercial interests.
When photon hits solar cell, its energy breaks apart electronhole pairs. Dec 11, 20 solar frontier announced on tuesday that it had set a new conversion efficiency record for czts solar cells measuring 0. The solar cell efficiency in czts was increased to 5. Also provided is a method for fabricating a cigs or cztsbased thinfilm solar cell by which conversion of molybdenum back electrode layer to molybdenum diselenide is controlled. Nanomaterials free fulltext fabrication of cu2znsns4. Beyond 11% efficient sulfide kesterite cu2znxcd1xsns4 solar. However, problems such as coexistence of complex secondary phases, the band tailing issue, short minority lifetime, bulk defects, and undesirable band alignment at pn interfaces need to be addressed for further. Conclusion in the czts solar cell development, significant progress on this relatively new research area has been achieved in recent years. Basic structure of czts solar cell the schematic structure of czts solar cell is shown in figure 2. In this work, we fabricated czts nanocrystal inks by a wet ball milling method, with the use of only nontoxic solvents, followed by filtration. We performed centrifugation to screen the asmilled czts and obtain nanocrystals.
Czts thin film solar cells the science behind the research kesterite cu 2 znsns 4 czts materials have direct band gap energies ranging from 1. The low cost, environmental harmless cu 2 znsns 4 cztsbased thin film solar cells are fabricated by using abundant materials. A high open circuit voltage of 809 mv is obtained for an ordered czts absorber with cds buffer layer, while a 9. Deposition and characterization of cu2znsns4 thin films for. Each of the first three quarters of the subcontract has been detailed in quarterly reports. Copper zinc tin sulfide czts thin films have been grown on glass substrates at 400 oc by using chemical spray pyrolysis as relatively fast and vacuum free method. The czts film possesses promising characteristic optical properties. Researchers at the university of new south wales unsw have achieved a world record conversion efficiency of 7. The researchers are synthesizing the cis and czts based solar cells with the composition of cu, zn, sn, in and s elements. Sputtering of precursors for cu2znsns4 solar cells and application. Since the discovery of its photovoltaic effect in 1966, cu2znsns4 czts has been widely studied for solar cell applications with the highest efficiency of 9. Solar frontiers previous record for a czts cell was 11. The cigs or cztsbased thinfilm solar cell causes no interlayer delamination and has improved durability and photoelectric conversion efficiency.
Surfactantfree czts nanoparticles as building blocks for. Pv technologies, thin film solar cells based on czts can be a potential candidate owing to its non toxic earth abundant constituent and high detailed balance limit of 32. Here, substitution of cd improves the bulk quality of czts, resulting in a photocurrent enhancement of 4 ma cm. Solar cells using nontoxic abundant materials cuingase 2 20. Synthesis of ligandfree czts nanoparticles via a facile hot injection. Pdf effect of czts parameters on photovoltaic solar cell. A unique architecture for liquid junction solar cell made of znoal. To increase the performance of cztsbased solar cell, buffer layer optimization is still an obstacle.
However, problems such as coexistence of complex secondary phases, the band tailing issue, short minority lifetime, bulk defects, and undesirable band alignment at pn interfaces need to be addressed for further efficiency improvement. Exploring cdfree buffer layer for czts photocathode for. Czts is a promising photoabsorber as a photocathode for water reduction to produce hydrogen but its performance is often limited by the presence of a high concentration of defects. Solar cells with an efficiency of 19% have been fabricated with an absorber bandgap in the range of 1. As solar energy is infinite, clean, and the most abundant renewable energy resource solar cells can be used in everyday life to convert sunlight directly into electricity yang et al. The other part of a solar cell is doped with the element boron with 3 electrons in its outer shellto become ptype silicon. Now, when this two type of silicon interact, an electric field forms at the junction which prevents more electrons to move to pside.
1095 654 725 1066 1387 1066 1287 806 481 854 786 1181 1486 1193 929 1290 1232 389 1159 836 378 1547 32 272 1021 1232 1298 1065 931 817 831 816