Impact of Oxygen on the Electronic Structure of Triple-Cation Halide Perovskites
Impact of Oxygen on the Electronic Structure of Triple-Cation Halide Perovskites
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DOI：
10.1021/acsmaterialslett.9b00294
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发表时间：
2019-11-01
影响因子：
11.4
通讯作者：
Islam, M. Saiful
中科院分区：
文献类型：
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作者：
Szemjonov, Alexandra;Galkowski, Krzysztof;Islam, M. Saiful
含有 Cs、甲基铵 (MA) 和甲脒 (FA) 阳离子混合物的合金三 A 阳离子钙钛矿由于其高光伏性能和相对稳定性而引起了人们的广泛关注。然而，对其空位缺陷行为以及分子氧对其电子和稳定性的影响的基本了解有限。在这项计算-实验相结合的研究中，我们研究了 (FA,MA,Cs)Pb(I,Br)(3) 模型系统，其模拟原子结构首次提出并得到 X 射线衍射数据的支持。我们研究了碘化物空位和 O-2 分子如何影响局部几何形状和电子结构。我们的计算在开尔文探针接触电位差和光致发光测量的支持下表明，O-2 的引入会产生 p 掺杂三阳离子钙钛矿并钝化碘化物空位，从而提高发光效率。这些结果对光电器件中混合阳离子钙钛矿的性能和稳定性具有重要意义。
Alloyed triple A-cation perovskites containing a mixture Cs, methylammonium (MA), and formamidinium (FA) cations are attracting intense attention because of their high photovoltaic performance and relative stability. However, there is limited fundamental understanding of their vacancy defect behaviour and influence of molecular oxygen on their electronic and stability properties. In this combined computational-experimental study, we investigate the (FA,MA,Cs)Pb(I,Br)(3) model system with its simulated atomistic structure presented for the first time and supported by X-ray diffraction data. We examine how iodide vacancies and O-2 molecules influence the local geometry and electronic structure. Our calculations, supported by Kelvin Probe contact potential difference and photoluminescence measurements, show that introduction of O-2 leads to a p-doped triple-cation perovskite and passivates iodide vacancies, resulting in enhanced luminescence efficiency. These results have important implications for the performance and stability of mixed-cation perovskites in optoelectronic devices.