【作者】 李辉；

【导师】 危书义； 王天兴；

【作者基本信息】 河南师范大学 ， 凝聚态物理， 2015， 硕士

【摘要】 近年来随着人类科技的飞速发展,能源大量的消耗,有的接近于枯竭,并且由于煤、石油、天然气等化石燃料的大量燃烧,使得空气质量年年下滑,对人们的生活带来了很大的影响。人们除了要面临能源紧缺的问题,同时还得想办法解决环境污染所带来的问题。因此,寻找一种绿色无污染的清洁能源,近年来成为人们研究的热点话题。太阳能电池以其廉价、高效率的特点,被人们认为是一种持续无污染的新能源,越来越多的受到人们的关注。铜铟镓硒纳米材料属于I2-II-IV-VI4四元半导体材料,这种半导体材料因其具有宽的吸收系数和高的稳定性[1,2],并且禁带宽度和太阳光谱匹配很好,近年来,成为制备太阳能电池吸收层的很具前景的光伏材料[3,4]。日前,相关薄膜太阳能电池已成功的投入到生产中。但是因为铜铟镓硒薄膜材料中含有地球中含量稀少并且昂贵的In和Ga元素,并且In和Ga元素有毒,使CIGS太阳能电池在发展中受到了很大的限制。铜锌锡硫(CZTS)是近年来新研究出的I2-II-IV-VI4型四元半导体材料,由于所含各元素在地壳中含量都非常丰富,给制备提供了大量的原材料物资。除此之外,作为一种直接带隙的半导体材料,铜锌锡硫的禁带宽度值接近于1.5 e V,吸收系数高达104 cm-1,吸收谱与太阳光谱吻合较好。以上种种优点,使CZTS受到人们越来越多的关注和研究[5]。理论推导CZTS薄膜太阳能电池的理想极限转换效率是32.2%[6,7],然而目前实验报道的最高的转换效率还比较低,仅仅只有12.6%,实验值和理论值还有相当大的差距,因此如何进一步提高铜锌锡硫薄膜太阳能电池的转换效率成为人们研究的主要问题。由于吸收层是太阳能电池的主要部分,它的质量的好坏,直接影响着电池的转换效率,如何提高吸收层的质量,制备出结晶性好,光吸收性好的吸收层,成为本论文主要的研究工作。本文的主要内容是采用热注入方法制备CZTS纳米材料。在实验中,我们使用油胺作为溶剂以及表面活性剂,乙酰丙酮铜为铜源,醋酸锌为锌源,氯化亚锡为锡源,高纯硫为硫源,来合成CZTS纳米材料。在实验过程中通过改变反应温度、反应时间以及溶剂的使用量来优化合成铜锌锡硫纳米颗粒。通过X射线衍射、紫外-可见分光光度仪、扫描电子显微镜和透射电子显微镜来对样品的物相、光学吸收性能、表面形貌、电子衍射区等进行表征。表征结果的对比分析表明:270℃热注入温度下反应30分钟得到的CZTS纳米晶性能最优。挑选出最优的CZTS纳米颗粒,经过研磨分散旋涂制备成薄膜样品,对制成的薄膜样品进行性能的表征测试,从而得到适合做太阳能电池吸收层的CZTS材料合适的制备条件,为后期制备薄膜太阳能器件做准备。更多还原

【Abstract】 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.更多还原