薄膜太阳能电池吸收层半导体Cu2ZnSnS4和Cu2ZnSnSe4中表面和界面性质的理论研究

项目名称： 薄膜太阳能电池吸收层半导体Cu2ZnSnS4和Cu2ZnSnSe4中表面和界面性质的理论研究

项目编号： No.91233121

项目类型： 重大研究计划

立项/批准年度： 2013

项目学科： 信息四处

项目作者： 陈时友

作者单位： 华东师范大学

项目金额： 80万元

中文摘要： 由于具有组成元素储量丰富、光吸收强等优点，Cu2ZnSnS4 (CZTS)和Cu2ZnSnSe4 (CZTSe)相关薄膜太阳能电池的研究自2009年以来显著升温。作为多晶薄膜材料，其表面和界面对光电性能有何影响，能否像Cu(In,Ga)Se2 (CIGS)一样，对界面有良性包容（即界面的存在有利于光生电子-空穴对的分离和电池效率的提高），目前还是一个问题。由于化学成分和晶体结构的复杂，实验上和理论上研究CZTS、CZTSe的表面和界面性质都仍有很大困难。本项目拟利用最近发展的第一性原理全局结构优化算法，预测不同合成气氛下CZTS、CZTSe的表面和界面构型，研究其电子结构及对样品电学、光学性能的影响，以回答这一问题，并探索通过改善界面性质提高电池效率的方法。

中文关键词： 薄膜太阳能电池；Cu2ZnSnS4；Cu2ZnSnSe4；表面和界面；第一性原理计算

英文摘要： Cu2ZnSnS4 (CZTS) and Cu2ZnSnSe4 (CZTSe) draw increasing attention as thin film solar cell absorbers recently, because they are earth-abundant and also have high light absorption coefficients. It is currently an open question how the surfaces and interfaces in CZTS and CZTSe thin films influence their photovoltaic performance, i.e., whether their interfaces can facilitate the separation of the photo-generated electron-hole pairs and enhance the efficiency of the multi-crystalline solar cells, like in the Cu(In,Ga)Se2 (CIGS) solar cells . Due to the complication in the chemical component and the crystal structure, it is still a challenge to study the properties of surfaces and interfaces in CZTS and CZTSe both experimentally and theoretically. In this project, we will utilize the recently-developed crystal structure prediction method based on the first-principles calculation and the global optimization algorithm, to study the microstructure of the surfaces and interfaces of CZTS and CZTSe, as well as their electronic structure and the related electrical and optical properties. Our study will give an answer to the aforementioned problem and come up with new methods to change the interfaces and improve the solar cell performance.

英文关键词： Thin Film Solar Cells；Cu2ZnSnS4；Cu2ZnSnSe4；Surface and interface；Frist-principles Calculation