Publication date: Nov 04, 2022
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 Hubbard parameters when dealing with HPs that often possess intricate competitions between onsite localization and intersite hybridization.
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all_structures.zip
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12.3 KiB | all_structures includes all the structures optimized by PBE (in vasp format) |
DFT+U_example.zip
MD5md5:3f979d343d9a41c01b1ccaf538bb108a
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1.1 MiB | An example of DFT+U (QE scripts) |
DFT+U+V_example.zip
MD5md5:923972e831ae9521d4cf6b9ed5b39924
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1.1 MiB | An example of DFT+U+V (QE scripts) |
ReadMe.txt
MD5md5:4cd8777a9ae6f0c656eba7cca23bd78d
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503 Bytes | ReadMe file |
2022.135 (version v1) [This version] | Nov 04, 2022 | DOI10.24435/materialscloud:wt-91 |