无机材料学报2022，Vol.37Issue(6)：691-696,6.DOI:10.15541/jim20210491
Cs2SnI6低指数晶面稳定性的第一性原理计算研究
Stability of Low-index Surfaces of Cs2SnI6 Studied by First-principles Calculations
摘要
Abstract
Cs2SnI6 is a stable and environmentally friendly halide perovskite material with great potential for photovoltaic and optoelectronic applications. While the surface properties are of paramount importance for device fabrications, there have been no such theoretical studies on this material. Using density functional theory calculations with the SCAN+rVV10 functional, the (001), (011) and (111) surfaces of Cs2SnI6 were studied to reveal their thermodynamic stability. We constructed seven models for these surfaces, including two along the (001) orientation (CsI2- and SnI4-terminated surfaces), two along the (011) orientation (I4- and Cs2SnI2-terminated surfaces) and three along the (111) orientation (non-stoichiometric CsI3-, Sn- and stoichiometric CsI3-terminated surfaces). Because most of the surfaces are non-stoichiometric, their relative stability depends on the experimental preparation condition, which is reflected by the chemical potentials of the constituent elements in the calculation. By determining the allowed chemical potential region, the thermodynamic stability of these Cs2SnI6 surfaces is analyzed. The results show that the surface energies of the (001) and (011) surfaces are affected by the chemical potentials, while the stoichiometric CsI3-terminated (111) surface is unaffected by the chemical potentials and is energetically the most stable surface of Cs2SnI6. Thus, the observed exposure of (111) surface of Cs2SnI6 crystals in several recent experiments is determined to be driven by thermodynamics.关键词
钙钛矿/表面能/Cs2SnI6/光伏材料/发光材料Key words
perovskite/surface energy/Cs2SnI6/photovoltaic material/luminescent material分类
化学化工引用本文复制引用
林啊鸣,孙宜阳..Cs2SnI6低指数晶面稳定性的第一性原理计算研究[J].无机材料学报,2022,37(6):691-696,6.基金项目
Shanghai International Cooperation Project(20520760900) （20520760900）
