目前Cu2ZnSn(S,Se)4(CZTSSe)薄膜太阳电池难以应用的关键是转换效率低，这主要是由于CZTSSe薄膜的高电阻及其与背电极的非欧姆接触导致的串联电阻大和CZTSSe与过渡层不匹配引起的开路电压小造成的。为此，本项目提出利用高压合成和后热处理新技术制备CZTSSe薄膜，通过调整压力和温度控制薄膜成分、减少本征缺陷、提高晶粒尺寸和致密度以降低薄膜电阻；研究CZTSSe与背电极界面的结构和电性及其对串联电阻的影响和机制，探索实现低阻欧姆接触的方法和技术；制备以（Cd1-xZnx）S或Zn(S,O)为过渡层的CZTSSe太阳电池，研究过渡层的性能及其与CZTSSe的晶格失配和能带排列方式对内建电场的结构和性能以及光生电子空穴的分离、复合和输运的影响规律和机制，探寻提高开路电压的方法和技术。通过优化电池结构和制备工艺，减少串联电阻，提高开路电压，制备高效、环保的CZTSSe太阳电池。

It is well known that the difficult in appliaction of Cu2ZnSn(S,Se)4(CZTSSe) thin film solar cell is low conversion efficiency, which results mainly from large series resistance,induced by high resistance of the CZTSSe film and non-ohm contact between tha CZTSSe and back electrode,and low open circuit voltage reduced by mismatch of the interface of buffer layer and CZTSSe.To solve the problems,it is suggested in the present project to synthesize CZTSSe target under high pressure,and then grow the CZTSSe films by using of sputtering or PLD and the target and finally anneal the films under high pressure non-toxic gas,the whole fabriaction process is non-toxic and composition controllable, and the electrical resistance of the film can be decreased by optimizing the composition,native deffects.grain size and density of the film via adjusting the pressure and temperature; to study structure and electrical properties of the CZTSSe/back electrode interface and effect of them on the series resistance, searching approach of preparation of the ohm contact interface with low resistance;to prepare CZTSSe based solar cell using (Cd1-xZnx)S or Zn(S,O)alloy as buffer layers, investigating effects of the buffer layers'properties as well as lattice mismatch and band alignment between the buffer layers and CZTSSe on structure and proeprties of the built-in fild, and segregation,recombination and transportation of photo-generated electron and hole, and exploring method and technique of improvement of open circuit voltage. We will decrease the series resistance and increase open circuit voltage by optimizing the structure of the solar cell as well as its praparation approach and technique, so that fabircate non-toxic CZTSSe based solar cell with high conversion efficiency.