Density Functional Theory Analysis of Structural, Electronic, and Optical Properties of Mixed-Halide Orthorhombic Inorganic Perovskites

Hamid M Ghaithan; Zeyad A Alahmed; Saif M H Qaid; Abdullah S Aldwayyan

doi:10.1021/acsomega.1c04806

Density Functional Theory Analysis of Structural, Electronic, and Optical Properties of Mixed-Halide Orthorhombic Inorganic Perovskites

ACS Omega. 2021 Nov 5;6(45):30752-30761. doi: 10.1021/acsomega.1c04806. eCollection 2021 Nov 16.

Authors

Hamid M Ghaithan¹, Zeyad A Alahmed¹, Saif M H Qaid¹, Abdullah S Aldwayyan^{1

2

3}

Affiliations

¹ Physics and Astronomy Department, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia.
² King Abdullah Institute for Nanotechnology, King Saud University, P.O. Box 2454, Riyadh 11451, Saudi Arabia.
³ K.A.CARE Energy Research and Innovation Center at Riyadh, P.O. Box 2022, Riyadh 11454, Saudi Arabia.

Abstract

Inorganic metal-halide perovskites hold a lot of promise for solar cells, light-emitting diodes, and lasers. A thorough investigation of their optoelectronic properties is ongoing. In this study, the accurate modified Becke Johnson generalized gradient approximation (mBJ-GGA) method without/with spin orbital coupling (SOC) implemented in the WIEN2k code was used to investigate the effect of mixed I/Br and Br/Cl on the electronic and optical properties of orthorhombic CsPb(I_1-x Br _x )₃ and CsPb(Br_1-x Cl _x )₃ perovskites, while the Perdew-Burke-Ernzerhof generalized gradient approximation (PBE-GGA) method was used to investigate their structural properties. The calculated band gap (E _g) using the mBJ-GGA method was in good agreement with the experimental values reported, and it increased clearly from 1.983 eV for CsPbI₃ to 2.420 and 3.325 eV for CsPbBr₃ and CsPbCl₃, respectively. The corrected mBJ + SOC E _g value is 1.850 eV for CsPbI₃, which increased to 2.480 and 3.130 eV for CsPbBr₃ and CsPbCl₃, respectively. The calculated photoabsorption coefficients show a blue shift in absorption, indicating that these perovskites are suitable for optical and optoelectronic devices.