Cu2ZnSnS4 (CZTS)使用地壳丰富的元素、无毒、低成本，是极具潜力的薄膜太阳能电池的吸收层材料。但CZTS 薄膜太阳电池的光-电转换效率在最近几年并没有取得突破性提高，开路电压过小是限制其转换效率的提高的重要原因，这一方面与CZTS吸收层自身的反对位缺陷、次生相（包括其他相结构）等有关，另一方面又与其带边与缓冲层的关系有关。阳离子替位掺杂是解决这些问题的有效方法。但目前阳离子替位掺杂CZTS的研究主要还只集中在单一金属阳离子的替位掺杂上。而单一金属阳离子的替位掺杂，很难同时兼顾能带结构特性（尤其是带隙和带边）和相转变这两个影响CZTS性能的重要因素。.本项目拟通过Ag、Fe双金属阳离子的替位共掺，来实现对CZTS的能带结构特性和相转变的协同调控：一方面改变CZTS的能带结构，使其带隙大小合适，并同时降低价带顶使其接近CIGS价带顶；另一方面能够对CZTS不同的相实现选择性合成。

The Cu2ZnSnS4 (CZTS) composed of naturally abundant and nontoxic elements is a promising absorbent layer material of thin film solar cell. However, the photovoltaic energy conversion efficiency of CZTS thin film solar cells has not been significantly improved in recent years. The low open circuit voltage is an important barrier for efficiency improvement, which is related to the antisite defects and secondary phase (including other phase structure) of CZTS itself, and the relationship between band edge and buffer layer. Cation substitution is an approach to solve these problems. However, the present study of cation substitution in CZTS is only focused on the substitution with single metal cation. The substitution with single metal cation is difficult to tune the band structure characteristics (especially band gap and band edge) and phase transition simultaneously which are the important factors affecting the performance of CZTS..This project focuses on the fundamental understanding of the co-doping of substitutional Ag and Fe in CZTS, aiming to provide a method of precise control for the band structrue and the crystallographic phases at the same time.