Cost-Effective High-Throughput Calculation Based on Hybrid Density Functional Theory: Application to Cubic, Double, and Vacancy-Ordered Halide Perovskites

Abstract

Hybrid density functional theory calculations are commonly used to investigate the electronic structure of semiconductor materials but have not been ideal for high-throughput calculations due to heavy computation costs. We developed a computational approach to obtain the electronic band gap cost-effectively by employing not only non-selfconsistent field calculation methods but also sparse k-point meshes for the Fock exchange potential. The benchmark calculation showed that our method is at least 30 times faster than the conventional hybrid density functional theory calculation to quickly screen materials. The band gaps of 290 materials in 5 different structures including cubic, double, and vacancyordered perovskites were obtained. The physical properties of Cs 2 WCl 6 and Cs 2 NaInBr 6 , screened for optoelectronic applications, were in good agreement with the experiment.

Impact of the Polymorphism and Relativistic Effects on the Electronic Properties of Inorganic Metal Halide Perovskites

“…22 Hybrid functionals with high exact ex. percentage (43− 45%) 15,23 and GW 24 have provided gap energies for CsGeI 3 (1.57 eV, HSE ex.=45% +SOC), 15 CsSnI 3 (1.01 eV, GW+SOC), 13 and CsPbI 3 (1.62 eV, GW+SOC) 25 in better agreement with the experimental reports. However, if for the HSE functional the exact exchange part needs to be tuned, on the other hand, its high computational cost is the Achilles' heel for studies involving polymorphs represented by large supercells, which for GW would be unthinkable.…”

Search of chalcopyrite materials based on hybrid density functional theory calculation

“…The conventional HSE calculations cost 4 times longer calculation time than the calculation with the downsampling factor. This clearly shows the cost-effectiveness of the downsampled k-points for highthroughput calculations, consistent with our recent study [31].…”

“…Here the computation cost was reduced by setting the downsampling factor for the Fock exchange potential to 2 [42]. Our previous studies show that this approach reduces the computation cost of the hybrid DFT calculation without losing much accuracy [31,[43][44][45]. In other words, when a 6 × 6 × 6 k-point grid is employed with the downsampling factor of 2, a downsampled 3 × 3 × 3 grid was used for the Fock exchange potential.…”

“…Because of the restriction, semi-local functionals or meta-generalized gradient approximation (meta-GGA) calculations were usually employed to obtain the electronic band gap [27][28][29]. But certainly, more advanced calculation methods like hybrid DFT or GW calculations should be pursued for more accurate screening [30,31].…”