Chen Yuetian, Wang Xingtao, Wang Yao, Liu Xiaomin, Miao Yanfeng, Zhao Yixin
School of Environmental Science and Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, Shanghai 200240, China.
School of Environmental Science and Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, Shanghai 200240, China; Shanghai Non-carbon Energy Conversion and Utilization Institute, Shanghai 200240, China; State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240, China.
Sci Bull (Beijing). 2023 Apr 15;68(7):706-712. doi: 10.1016/j.scib.2023.03.029. Epub 2023 Mar 17.
Efficiency and stability are the main research focuses for perovskite solar cells. Inorganic perovskites like CsPbI possess higher chemical stability than those with organic A-site cations, while they also exhibit higher defect density. Nonetheless, it is highly challenging to induce orderly secondary arrangement or reconstruction of inorganic perovskites with reduced defects because of their unique chemical properties. In this work, in-situ three-dimension-to-zero-dimension (3D-to-0D) phase transformation and surface reconstruction on CsPbI film is achieved as induced by a functional organic cation, benzyldodecyldimethylammonium (BDA), a process of which that is similar to phase-transfer catalysis. With the help of BDABr salt treatment, 0D CsPbI perovskites are secondarily formed along CsPbI grain boundaries with Cs-related cationic defects passivated, yielding structures of higher stability. The BDA-CsPbI films exhibit reduced non-radiative recombination and promoted charge transfer, leading to inorganic perovskite solar cells with a high power conversion efficiency of 20.63% and good operational stability.
效率和稳定性是钙钛矿太阳能电池的主要研究重点。像CsPbI这样的无机钙钛矿比那些含有有机A位阳离子的钙钛矿具有更高的化学稳定性，然而，它们也表现出更高的缺陷密度。尽管如此，由于其独特的化学性质，诱导无机钙钛矿进行有序的二次排列或减少缺陷的重构极具挑战性。在这项工作中，通过一种功能性有机阳离子苄基十二烷基二甲基铵（BDA）诱导，实现了CsPbI薄膜上原位的三维到零维（3D到0D）相变和表面重构，这一过程类似于相转移催化。借助BDABr盐处理，沿CsPbI晶界二次形成0D CsPbI钙钛矿，钝化与Cs相关的阳离子缺陷，产生更高稳定性的结构。BDA-CsPbI薄膜表现出减少的非辐射复合和促进的电荷转移，从而得到功率转换效率高达20.63%且具有良好运行稳定性的无机钙钛矿太阳能电池。
