Chen Siqi, Wang Jin, Ran Guangliu, Pan Qingyan, Liu Le, Zhao Chengjie, Tang Jin, Zhao Min, Zhang Wenkai, Zhao Yingjie, Jiu Tonggang
Science Center for Material Creation and Energy Conversion, Institute of Frontier and Interdisciplinary Science, Shandong University, Qingdao, 266237, China.
Qingdao University of Science and Technology, Qingdao, 266042, China.
Small Methods. 2021 Dec;5(12):e2101079. doi: 10.1002/smtd.202101079. Epub 2021 Oct 15.
The ionic nature of organic trihalide perovskite leads to structural irregularity and energy disorder at the perovskite surface, which seriously affects the photovoltaic performance of perovskite solar cells. Here, the origin of the perovskite surface disorder is analyzed, and a facial ion-exchange strategy is designed to regulate the surface chemical environment. By the reconstruction of terminal irregular Pb-I bonds and random cations, the repaired surface is characteristic of the reduced band tail states, consequent to the suppression of the uplift of quasi-Fermi level splitting and photocarrier scattering. The optimized device gets a high open-circuit voltage and operational stability. These findings fully elaborate the underlying mechanism concerning perovskite surface problem, giving guidance on tailoring the energy disorder.
有机三卤化物钙钛矿的离子性质导致钙钛矿表面的结构不规则和能量无序，这严重影响了钙钛矿太阳能电池的光伏性能。在此，分析了钙钛矿表面无序的起源，并设计了一种简便的离子交换策略来调节表面化学环境。通过对末端不规则的Pb-I键和随机阳离子的重构，修复后的表面具有减少的带尾态特征，这归因于准费米能级分裂的上升和光载流子散射的抑制。优化后的器件具有高开路电压和运行稳定性。这些发现充分阐述了关于钙钛矿表面问题的潜在机制，为调整能量无序提供了指导。
