钙钛矿太阳能电池铜铁矿型空穴传输材料的合成、结构及性能研究

Organic molecules or conducting polymers are commonly used as the hole-transporting materials in the typical perovskite-based solar cells. However, the low hole-mobility and poor long-term stability of these materials hinder the perovskite-based solar cells from further enhancements in photovoltaic performances and commercial applications. Therefore, it is desirable to develop stable hole-transporting materials with high hole-mobility for perovskite-based solar cells. .In this project, delafossite oxide nanocrystals (CuMO2) (M= Al, Cr, Sc, Ga) will be synthesized and explored for the applications in perovskite-based solar cells as hole-transporting materials. The delafossite oxide nanocrystals are stable p-type semiconductors with high hole-mobility, high transparency as well as matching well with perovskite layer. Delafossite nanocrystals will be synthesized via liquid-state synthesis techniques. Furthermore, the dependence of photovoltaic performances of devices on the delafossite nanocrystals with controllable sizes, structures and morphologies will be investigated in detail using electrochemical methods and transient spectroscopy techniques. Moreover, the interface between the hole-transporting layer and the perovskite layer will be finely modified to reduce the charge recombination, and thus, enhance the charge extraction efficiency. Finally, highly efficient and stable perovskite-based solar cells will be achieved. .The results of the proposal will provide deep understanding of the function of hole-transporting materials used in perovskite-based solar cells. Meanwhile, we will further provide new materials, new technologies and new methods for the highly efficient and stable perovskite-based photovoltaic devices.

钙钛矿太阳能电池所采用的有机小分子和导电聚合物空穴传输材料空穴迁移率低和稳定性差，制约了钙钛矿太阳能电池的进一步发展。探索高迁移率、高稳定性的空穴传输材料是发展钙钛矿太阳能电池的关键。.本项目拟发展稳定性好、空穴迁移率高、且与钙钛矿层能级匹配的铜铁矿CuMO2 (M= Al, Cr, Sc, Ga) p型半导体作为新型空穴传输材料。拟采用液相合成法制备铜铁矿半导体纳米晶，通过调控纳米晶组成、尺寸、形貌、暴露晶面等参数，结合光电化学及瞬态光谱技术等手段，考察空穴传输材料与电池光电转换效率之间的内在关系，阐明铜铁矿纳米晶对器件性能的作用机理。结合成膜工艺，改善空穴传输层与衬底及吸光层之间的间界面接触以降低界面复合，提高载流子抽取效率，最终获得高效、稳定钙钛矿太阳能电池。本项目的实施将进一步提高对空穴传输材料的认识，为钙钛矿太阳能电池的发展提供新材料、新技术和新方法。

项目按照原计划顺利开展研究，实现了预期目标，提出了一种新的铜铁矿纳米晶合成方法。以Cu2O作为模板，依据“软硬酸碱理论”，用弱碱刻蚀Cu2O模板得到Cu2O@Cr(OH)3核壳结构，再结合煅烧得到结晶性良好且优先取向的CuCrO2纳米晶，该方法不仅避免了传统水热法合成耗时长的问题，而且可以实现多种金属离子对铜铁矿的掺杂；同时，详细研究了铜铁矿CuCrO2纳米晶修饰钙钛矿/空穴传输层间界面对器件光电性能的影响机制；通过器件各部分的优化，获得了光电转换效率为23.16%的高效稳定的钙钛矿电池器件。同时，拓展了其他铜基p型半导体材料（Fe1-xCuxS2）的制备及成膜技术，获得了17.5%的光电转换效率器件。开发了Cs4PbBr6/PDMS复合薄膜和CsPbX3 (X = Cl, Br, I) /聚苯乙烯复合薄膜成膜技术，这两种材料为稳定钙钛矿纳米晶复合材料，它们为提高钙钛矿的稳定性和扩展其潜在高性能防伪应用奠定了实验基础。最后，制备的碳基非贵金属单原子催化剂和硒化物/碳复合催化剂对I3-/I-氧化还原电对的还原过程有高效的催化性能，是理想的非Pt催化剂材料。.截止2021年底，在本项目支持下，以通讯联系人发表SCI论文13篇，申请中国专利1项；指导硕士毕业生4人，在读研究生2名。同时，与国家纳米科学中心建立了良好的合作关系。