论文标题
卤化物钙钛矿的Hubbard模型中的现场和场地电子相关性
Onsite and intersite electronic correlations in the Hubbard model for halide perovskites
论文作者
论文摘要
卤化物钙钛矿（HPS）被广泛视为可见光谱中合适的带隙的有前途的光伏和发光材料。使用（半）局部交换相关功能的密度功能理论（DFT）计算通常低估了这些系统的频带差距。对HP的电子结构的准确描述通常需要高阶理论水平，例如HEYD-SCUSERIA-ERNZERHOF（HSE）混合密度函数和GW近似值，这些功能和GW近似在计算上比标准DFT贵得多。在这里，我们使用DFT+U+V使用DFT+U+V，使用on Site-note u and Soite u and Soite v Hubbard参数计算出无需使用Pircorie of的Priefi cantumption，我们研究了三种代表性的HPS，ABX3 HAPES，空位订购的双重钙钛矿（VODPS）（VODPS）和键不成比例的Halide Perovskites（BDHPS），而无需使用OnSite u和Sote v Hubbard参数计算自我限制。哈伯德校正的包含将所有三种类型的HP的频带隙预测精度提高到了类似的高级方法。此外，自洽的哈伯德u是HPS中多价值金属原子的真实局部电荷状态的有意义的指标。跨站点Hubbard V的包含对于正确捕获具有呼吸模扭曲的Halide octahedra的BDHP的相邻原子上的价电子之间的杂交至关重要。特别是，哈伯德参数和晶体几何的同时收敛使带隙预测精度优于BDHP，但成本的一部分。我们的工作强调了在处理通常在现场定位和现场杂交之间具有复杂竞争的HP时，使用自洽的Huabbard参数的重要性。
Halide perovskites (HPs) are widely viewed as promising photovoltaic and light-emitting materials for their suitable band gaps in the visible spectrum. Density functional theory (DFT) calculations employing (semi)local exchange-correlation functionals usually underestimate the band gaps for these systems. Accurate descriptions of the electronic structures of HPs often demand higher-order levels of theory such as the Heyd-Scuseria-Ernzerhof (HSE) hybrid density functional and GW approximations that are much more computationally expensive than standard DFT. Here, we investigate three representative types of HPs, ABX3 halide perovskites, vacancy-ordered double perovskites (VODPs), and bond disproportionated halide perovskites (BDHPs), using DFT+U+V with onsite U and intersite V Hubbard parameters computed self-consistently without a priori assumption. The inclusion of Hubbard corrections improves the band gap prediction accuracy for all three types of HPs to a similar level of advanced methods. Moreover, the self-consistent Hubbard U is a meaningful indicator of the true local charge state of multivalence metal atoms in HPs. The inclusion of the intersite Hubbard V is crucial to properly capture the hybridization between valence electrons on neighboring atoms in BDHPs that have breathing-mode distortions of halide octahedra. In particular, the simultaneous convergence of both Hubbard parameters and crystal geometry enables a band gap prediction accuracy superior to HSE for BDHPs but at a fraction of the cost. Our work highlights the importance of using self-consistent Huabbard parameters when dealing with HPs that often possess intricate competitions between onsite localization and intersite hybridization.
