Oxygen- and Water-Induced Energetics Degradation in Organometal Halide Perovskites
Oxygen- and Water-Induced Energetics Degradation in Organometal Halide Perovskites
复制标题
有机金属卤化物钙钛矿中氧和水引起的能量降解
DOI：
10.1021/acsami.8b04182
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发表时间：
2018
影响因子：
9.5
通讯作者：
Bao Qinye
中科院分区：
文献类型：
--
作者：
Yang Jianming;Yuan Zhongcheng;Liu Xianjie;Braun Slawomir;Li Yanqing;Tang Jianxin;Gao Feng;Duan Chungang;Fahlman Mats;Bao Qinye
有机金属卤化物钙钛矿正处于快速发展中，并且其稳定性已被重点关注，这目前是实际应用的主要障碍。能量学在器件的电荷注入/提取和输运特性中起着至关重要的作用。在这里，我们原位研究氧和水诱导的能量降解有机金属卤化物钙钛矿薄膜。氧气诱导钙钛矿薄膜的真空能级向上移动，因为氧诱导的表面偶极子的形成，水蒸气引起显著的真空能级下移，并且参考费米能级的价带结合能同时增加，从而保持钙钛矿薄膜的电离电位不变。此外，还详细监测和分析了其化学成分、晶体结构、表面形态和动力学性能。这些结果对于理解退化机制以及将来进行稳定材料和器件的优化是必不可少的。
Organometal halide perovskites are under rapid development, and significant focus has been placed on their stability that currently presents a major obstacle for practical application. Energetics plays a vital role in charge injection/extraction and transport properties in devices. Here, we in situ investigate oxygen- and water-induced energetics degradation in organometal halide perovskite films. Oxygen gas induces an upward shift of the vacuum level of the perovskite films because of the formation of an oxygen-induced surface dipole, water vapor causes a significant vacuum-level downshift, and the valence band binding energy referenced to the Fermi level simultaneously increases so as to keep the ionization potential of the perovskite films unchanged. Moreover, the chemical compositions, crystalline structures, surface morphologies, and dynamical properties also are monitored and analyzed in detail. These results are indispensable to understand the degradation mechanisms and to perform the optimizations of stable materials and devices in the future.