Wang Hailiang, Liu Huicong, Dong Zijing, Wei Xueyuan, Li Weiping, Zhu Liqun, Zhu Cheng, Bai Yang, Chen Haining
School of Materials Science and Engineering, Beihang University, Beijing 100191, China.
Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green Applications, MIIT Key Laboratory for Low-dimensional Quantum Structure and Devices, Experimental Center of Advanced Materials, School of Materials Science & Engineering, Beijing Institute of Technology, Beijing 100081, China.
Fundam Res. 2022 Jul 24;4(5):1110-1117. doi: 10.1016/j.fmre.2022.07.005. eCollection 2024 Sep.
Inorganic CsPbI perovskite has exhibited great application potential in perovskite solar cells (PSCs) due to its suitable optical bandgap and high chemical stability. However, the perovskite phases of CsPbI are not stable at room temperature, where they transition to non-perovskite phases. Humidity or water has been thought to be the primary factor inducing this phase transition, which should be avoided throughout the procedure of film and device processing. Surprisingly, the present study indicates that preparing a precursor solution in humid air is beneficial to the growth of high-quality CsPbI perovskite to enhance device performance. It is demonstrated that the incorporation of HO in the precursor solution from humid air or by intentional addition significantly changes the composition of coordination compounds and increases the amount of low iodine coordination complexes. As a result, the crystallization of dimethylammonium lead iodide (DMAPbI) intermediate is suppressed well, which accelerates its subsequent conversion to CsPbI perovskite. Consequently, an oriented CsPbI perovskite film with improved crystallinity and lower defect density is obtained. Most importantly, carbon-based PSCs (C-PSCs) based on the CsPbI perovskite film achieve an efficiency of 16.05%, a new record for inorganic C-PSCs.
无机CsPbI钙钛矿因其合适的光学带隙和高化学稳定性，在钙钛矿太阳能电池（PSC）中展现出巨大的应用潜力。然而，CsPbI的钙钛矿相在室温下不稳定，会转变为非钙钛矿相。湿度或水一直被认为是引发这种相变的主要因素，在整个薄膜和器件制备过程中都应避免。令人惊讶的是，本研究表明在潮湿空气中制备前驱体溶液有利于高质量CsPbI钙钛矿的生长，从而提高器件性能。结果表明，从潮湿空气中或通过有意添加使HO掺入前驱体溶液中，会显著改变配位化合物的组成，并增加低碘配位络合物的量。因此，二甲基碘化铅（DMAPbI）中间体的结晶得到很好的抑制，这加速了其随后向CsPbI钙钛矿的转化。最终，获得了结晶度提高且缺陷密度降低的取向CsPbI钙钛矿薄膜。最重要的是，基于CsPbI钙钛矿薄膜的碳基PSC（C-PSC）实现了16.05%的效率，这是无机C-PSC的新纪录。
