2025/04/10 by Butorin, Sergei M.
#FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci)
paper · doi:10.48550/arxiv.2504.07641
The recently introduced approach, combining the parameter-free Armiento-Kümmel generalized gradient approximation exchange functional with the nonseparable gradient approximation Minnesota correlation functional, was used to calculate the electronic structure of the Cs3Bi2Br9-xIx series within density functional theory including the spin-orbit coupling. The changes in the band gap size and its dependence on the x value was investigated. The band gap was found to be of indirect nature and it decreases with increasing I content as long as the system is in the P3m1 phase. A clear non-linear dependence of the band gap size on x was established which is in qualitative and quantitative agreement with reported experimental data. The quasi-rigid band behavior of the states in the valence and conduction bands of the P3m1 phase is discussed since no significant changes in the shape of the total density of unoccupied states were observed upon the isovalent substitution.