Qin Zhixiao, Chen Yuetian, Wang Xingtao, Wei Ning, Liu Xiaomin, Chen Haoran, Miao Yanfeng, Zhao Yixin
School of Environmental Science and Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, Shanghai, 200240, China.
Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200240, China.
Adv Mater. 2022 Aug;34(32):e2203143. doi: 10.1002/adma.202203143. Epub 2022 Jul 11.
Black-phase formamidinium lead iodide (FAPbI ) with narrow bandgap and high thermal stability has emerged as the most promising candidate for highly efficient and stable perovskite photovoltaics. In order to overcome the intrinsic difficulty of black-phase crystallization and to eliminate the lead iodide (PbI ) residue, most sequential deposition methods of FAPbI -based perovskite will introduce external ions like methylammonium (MA ), cesium (Cs ), and bromide (Br ) ions to the perovskite structure. Here a zwitterion-functionalized tin(IV) oxide (SnO ) is introduced as the electron-transport layer (ETL) to induce the crystallization of high-quality black-phase FAPbI . The SnO ETL treated with the zwitterion of formamidine sulfinic acid (FSA) can help rearrange the stack direction, orientation, and distribution of residual PbI in the perovskite layer, which reduces the side effect of the residual PbI . Besides, the FSA functionalization also modifies SnO ETL to suppress deep-level defects at the perovskite/SnO interface. As a result, the FSA-FAPbI -based perovskite solar cells (PSCs) exhibit an excellent power conversion efficiency of up to 24.1% with 1000 h long-term operational stability. These findings provide a new interface engineering strategy on the sequential fabrication of black-phase FAPbI PSCs with improved optoelectronic performance.
具有窄带隙和高热稳定性的黑色相甲脒碘化铅（FAPbI₃）已成为高效稳定的钙钛矿光伏领域最有前景的候选材料。为了克服黑色相结晶的固有困难并消除碘化铅（PbI₂）残留，大多数基于FAPbI₃的钙钛矿的顺序沉积方法会将诸如甲铵（MA⁺）、铯（Cs⁺）和溴离子（Br⁻）等外部离子引入钙钛矿结构。在此，引入一种两性离子功能化的二氧化锡（SnO₂）作为电子传输层（ETL），以诱导高质量黑色相FAPbI₃的结晶。用甲脒亚磺酸（FSA）的两性离子处理的SnO₂电子传输层有助于重新排列钙钛矿层中残留PbI₂的堆叠方向、取向和分布，从而减少残留PbI₂的副作用。此外，FSA功能化还修饰了SnO₂电子传输层，以抑制钙钛矿/SnO₂界面处的深层缺陷。结果，基于FSA-FAPbI₃的钙钛矿太阳能电池（PSC）表现出高达24.1%的优异功率转换效率，并具有1000小时的长期运行稳定性。这些发现为顺序制备具有改善的光电性能的黑色相FAPbI₃钙钛矿太阳能电池提供了一种新的界面工程策略。
