| In recent years, with the rapid development of science and technology, a lot of energy is used up, some close to exhaustion, and due to the burning of the large number of coal, oil, natural gas and other fossls fuels lead to poor air quality year by year, and people’s lives have also been brought great impaction. In addition to face the serious problems of environment, people also face the serious energy problems. So looking for a green pollution-free and clean energy has become a hot topic of research in recent years. As a new sustainable and non-pollution energy, the cheap, high efficiency solar cells in recent years, are attracted more and more attention. Copper indium gallium selenide nanomaterials belong to I2-II-IV-VI4 quaternary semiconductor of semiconductor materials, The semiconductor material is becoming a very promising photovoltaic material as a absorption layer of the solar cell, because of its wide absorbancy index and high stability, and the width of band gap matchs to the solar spectrum well. At present, the related thin film solar cell has been successfully put into production. Because the copper indium gallium selenide thin film material contains In and Ga elements which are rare in earch and the cost are high, besides the In and Ga elements are toxic, thus the industrial development of the CIGS solar cells has been very limited. Copper zinc tin sulfide(CZTS) as a new I2-II-IV-VI4 quaternary semiconductor material, has included four elements, which content in the earth are very rich, so the large number of raw materials are provided for preparation. In addition, as a direct band gap semiconductor material, the band gap width of copper zinc tin sulfur closes to 1.5e V, and its absorbancy index is 104 cm-1, absorption spectra are in good agreement with the solar spectrum. Because of the above advantages, the CZTS has become popular more and more and being studied by people. The ideal limit conversion efficiency of theoretical derivation of copper zinc tin sulfur film solar cell is 32.2%, but the highest conversion efficiency of the present experiment news is only 12.6%, compared with the experimental conversion efficiency, the theoretical conversion efficiency still has a long way to go. So the problem that how to improve the conversion of copper zinc tin sulfide thin film solar cell efficiency is becoming a main contents of research. Because the absorption layer is the main part of the solar cell, its quality affect the solar cell conversion efficiency. How to improve the quality of absorption layer, and prepare a good crystallinity and light absorbing good absorption layer becomes the mainly study of this paper. The main work of this paper is using the hot injection method to prepare copper zinc tin sulfide nano material. In the experiment, Oleylamine was used as the solvent and the surface active agent, copper acetylacetonate was used as copper, zinc acetate was used as a source of zinc, stannous chloride was used as the tin source, Sulfur powder with high purity was used as sulfur source, we use these material to synthesis the copper zinc tin sulfide nanocrystalline. The copper zinc tin sulfide nanocrystalline was optimized by changing the reaction temperature, reaction time and the amount of solvent in the reaction process. We tested the performance of sample such as crystal structure, optical absorption properties, surface morphology, district electron diffraction and so on by using X-ray diffraction, UV-VIS spectrophotometer, scanning electron microscopy and transmission electron microscopy. the comparative analysis of the representational results show we can get good performance of copper zinc tin sulfide at 270℃ for 30 minutes. We choose the best sample, and then the copper zinc tin sulfide thin films were prepared by spin coating, finally, it was observed by performance tests. So that we can find a suitable solar absorption layer of copper zinc tin sulfur material, and it is prepared for the preparation of thin solar cell in later rounds. |
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