基于微纳结构界面诱导晶化的高效平面异质结钙钛矿太阳能电池

Organic-inorganic hybrid perovskite materials are the ideal representatives in planar heterojunction photovoltaic cells owing to their advantages of near-perfect crystallinity, low cost, simple synthesis and solution-processing ability. Controllable growth of the crystalline perovskite films is regarded as the most important factor to obtain high-efficiency perovskite solar cells. This project proposes a novel route, named as the interface-induced crystallization progress based on the seed-mediation of micro/nano-structured interfacial layers, to control the growth of perovskite crystalline films with high quality. In details, we will develop two types micro/nano-structured interfacial layers. One is selecting and synthesizing metal oxides nano-particles, which will be doped into PEDOT:PSS dispersion solution to form nano-structured interfacial layers. Another is forming organic small molecule based micro/nano structure interfacial layers by self-assembly technique. The micro/nano-structured interfacial layers will act as the seeding underlayers of the perovskite films, which can induce and assist the crystallization of perovksite films. The project aims to control the defects and the film quality such as the grain size and the film coverage by optimizing the morphologies of micro/nano structure interfacial layers, and to clarify the induction mechanism and the crystal growth kinetics of the perovskite films. In addition, we will investigate the relations between the perovskite film quality and the cell efficiency via understanding the mechanisms of exciton generation and carrier transport behaviors. With efforts, the project will develop high-performance perovskite solar cells with efficiency exceeding 20%. The project provides a novel route for controlling the crystal growth of the perovskite films in planar heterojunction perovskite solar cells.

有机/无机杂化钙钛矿材料具有良好的晶体特性，其成本低廉、合成简单、又可通过溶液加工成膜，是平面异质结太阳能电池的理想选择。钙钛矿晶体薄膜的可控生长，对于其光伏器件的光电转换效率起着最关键的作用。本项目拟从钙钛矿晶体薄膜的晶化过程出发，开发制备与钙钛矿薄膜层相匹配的具有微纳结构的空穴界面层，通过界面诱导晶化以及晶体生长工程，可控生长高质量的钙钛矿晶体薄膜，研究晶核种子对薄膜的晶体质量、杂质缺陷等因素的影响。在理解光生载流子的产生机制、电荷的输运过程与机理的基础上，深入研究微纳结构界面诱导晶化和晶核种子生长法生长高质量钙钛矿晶体薄膜的动力学过程及微观物理机制，探索钙钛矿晶体薄膜的质量与电池效率之间的关系，制备光电转换效率超过20%的平面异质结钙钛矿太阳能电池，为开发高效率、稳定的平面异质结钙钛矿太阳能电池提供更多思路和理论依据。

本项目主要从钙钛矿晶体薄膜的晶化过程出发，选择、制备与钙钛矿薄膜层相匹配的具有微纳结构的空穴界面层，通过界面诱导晶化、以及晶体生长工程，可控生长高质量的钙钛矿晶体薄膜，研究晶核种子对薄膜的晶体质量、杂质缺陷等因素的影响。在理解光生载流子的产生机制、电子、空穴的输运过程与机理的基础上，研究界面诱导晶化制备高质量钙钛矿薄膜的动力学过程，探索钙钛矿晶体薄膜的质量与电池效率之间的关系，制备光电转换效率超过20%的平面异质结钙钛矿太阳能电池，为开发高效率、稳定的平面异质结钙钛矿太阳能电池提供更多思路和理论依据。.在有机/无机杂化界面功能层制备方面，开发了一系列与钙钛矿薄膜能级相匹配的微纳结构界面层，作为钙钛矿薄膜的晶核种子诱导层，通过晶核种子生长、界面诱导晶化的方法实现钙钛矿薄膜的可控生长。.在钙钛矿薄膜晶化控制方面，以提高钙钛矿太阳能电池的光电转换效率和改善其稳定性为目标，针对“结晶动力学-形貌调控-界面输运-器件性能”之间的内在关系等关键科学问题开展了创新性研究工作，在理论上研究影响薄膜晶化动力学过程以及表界面能量输运的关键机制，在实践上探索表界面调控以及有机/无机半导体掺杂的有效途径，在钙钛矿薄膜的晶化控制、体缺陷态和表面缺陷态钝化、表界面形貌调控以及高性能器件的应用制备方面取得了一系列创新性研究成果。在器件效率方面，在1个标准太阳光下适用于室外应用的钙钛矿太阳能电池的光电转换效率已达23.5%。.综上所述，本项目顺利完成了预定的研究计划，在高性能钙钛矿光伏器件制备的研究中，从有机/无机杂化界面功能层制备、晶化动力学、物理机制到工艺制备等方面取得了十分有意义的成果。