双阳离子掺杂和界面钝化对柔性CZTSSe太阳电池性能的调控作用

廉价环保的铜锌锡硫硒(CZTSSe)柔性太阳电池在便携式设备、航天航空等领域具有广阔的应用前景。但是，目前其转化效率仅为10.34%，主要受限于低的开路电压。本项目针对CZTSSe中存在大量的体缺陷、异质结界面态等导致的开路电压损耗大的问题，独辟蹊径提出采用溶液法和硒化技术在柔性Mo衬底上构筑双阳离子Ag&In共掺杂的CZTSSe（CAZTISSe）薄膜的新思路，以实现缺陷钝化和带隙调控。同时，通过控制环保型缓冲层ZnSnO（或ZnMgO）薄膜的元素比Zn/Sn（或Zn/Mg），与CAZTISSe薄膜构建一个结构和能带匹配的PN异质结CAZTISSe/ZnSnO（或CAZTISSe/ZnMgO），阐明其界面特性和钝化机制。进一步，将理论模拟与实验研究相结合，揭示Ag&In共掺杂、PN结特性与电池性能的相互关系，阐明提升该电池效率的一些关键物理机制，为发展新型绿色环保太阳电池提供新途径。

Cheap and environmental friendly flexible Cu2ZnSn(Sx,Se1-x)4 (CZTSSe) solar cells have a broad application prospect in portable equipment, aerospace and other fields. However, the power conversion efficiency is only 10.34% due to low open-circuit voltage (Voc). This research proposal aims to address the issues of large Voc loss caused by a large number of bulk defects and interface states of CZTSSe/CdS heterojunction. A new methodology is proposed to effectively passivate defects and adjust bandgap by preparing CZTSSe (CAZTISSe) thin films co-doped with double cations Ag&In on flexible Mo substrates via solution method and selenization technique. The Zn/Sn (or Zn/Mg) ratio of buffer layer ZnSnO (or ZnMgO) will be properly controlled to construct a CAZTISSe/ZnSnO (or CAZTISSe/ZnMgO) PN junction with suitable band alignment. The interface characteristics and carrier transport mechanism of the PN junction will be studied and revealed. By combining the theoretical simulation with experimental investigations, the relationships among Ag&In co-doping, PN heterojunction characteristics and device performances will be found. Key physical mechanisms for improving the efficiency of the flexible CAZTISSe solar cells will be clarified. The research results will provide a new way for the development of new green solar cells.