| Summary: | Predicting the energy band gap for FAPbI3 and MAPbI3 halide perovskites using density functional theory (DFT) methods often faces several difficulties and challenges. We investigated the effects of spin-orbit coupling (SOC) and dispersion corrections in DFT calculations on the crystal structure, electronic, and optical properties of MAPbI3 and FAPbI3 perovskites. Our findings indicate that incorporating SOC into LDA and GGA-PBE calculations improves the accuracy of energy band gap predictions for FAPbI3 and MAPbI3 structures. Furthermore, we demonstrate that adding dispersion corrections to GGA-PBE + SOC calculations indirectly affects structural relaxation, thereby enhancing the accuracy and consistency of MAPbI3 and FAPbI3 band gap values, which aligns with experimental data. Our new DFT approach, based on the cost-effective GGA-PBE + SOC + TS/MBD functional, accurately reproduces the electronic properties of MAPbI3 and FAPbI3, providing enhanced accuracy and consistency in calculating the energy band gap. © 2025 Elsevier B.V.
|
|---|