北京大学肖立新团队报道了在潮湿空气中形成黑相FAPbI₃钙钛矿的晶体封盖层。相关研究成果发表在2024年7月12日出版的《科学》。

黑相甲脒碘化铅（α-FAPbI₃）钙钛矿是光伏应用的理想相，但水会引发δ-FAPbI₄等光惰性杂质相的形成。

研究发现，钙钛矿制备的经典溶剂体系加剧了这种可重复性挑战。传统的配位溶剂二甲基亚砜（DMSO）因其吸湿性，在高相对湿度（RH）条件下促进了δ-FAPbI₃的形成。研究人员引入了含氯的有机分子来形成一个阻止水分渗透的覆盖层，同时保留基于DMSO的复合物来调节晶体生长。

研究报告了在20%至60%的相对湿度范围内，制造的钙钛矿太阳能电池的功率转换效率>24.5%，在80%相对湿度下为23.4%。在500小时的最大功率点运行后，未封装的器件在空气中（相对湿度为40%至60%）保持了96%的初始性能。

附：英文原文

Title: A crystal capping layer for formation of black-phase FAPbI3 perovskite in humid air

Author: Yu Zou, Wenjin Yu, Haoqing Guo, Qizhi Li, Xiangdong Li, Liang Li, Yueli Liu, Hantao Wang, Zhenyu Tang, Shuang Yang, Yanrun Chen, Bo Qu, Yunan Gao, Zhijian Chen, Shufeng Wang, Dongdong Zhang, Yihua Chen, Qi Chen, Shaik M. Zakeeruddin, Yingying Peng, Huanping Zhou, Qihuang Gong, Mingyang Wei, Michael Grtzel, Lixin Xiao

Issue&Volume: 2024-07-12

Abstract: Black-phase formamidinium lead iodide (α-FAPbI3) perovskites are the desired phase for photovoltaic applications, but water can trigger formation of photoinactive impurity phases such as δ-FAPbI3. We show that the classic solvent system for perovskite fabrication exacerbates this reproducibility challenge. The conventional coordinative solvent dimethyl sulfoxide (DMSO) promoted δ-FAPbI3 formation under high relative humidity (RH) conditions because of its hygroscopic nature. We introduced chlorine-containing organic molecules to form a capping layer that blocked moisture penetration while preserving DMSO-based complexes to regulate crystal growth. We report power conversion efficiencies of >24.5% for perovskite solar cells fabricated across an RH range of 20 to 60%, and 23.4% at 80% RH. The unencapsulated device retained 96% of its initial performance in air (with 40 to 60% RH) after 500-hour maximum power point operation.

DOI: adn9646

Source: https://www.science.org/doi/10.1126/science.adn9646