A generic Slater–Koster description of the electronic structure of centrosymmetric halide perovskites

The halide perovskites have truly emerged as efficient optoelectronic materials and show the promise of exhibiting nontrivial topological phases. Since bandgap is deterministic factor for these quantum phases, here we present a comprehensive electronic structure study using first-principle methods by considering nine inorganic CsBX$_3$ (B = Ge, Sn, Pb; X Cl, Br, I) in their three structural polymorphs (cubic, tetragonal orthorhombic). A series exchange-correlations (XC) functionals are examined towards accurate estimation bandgap. Furthermore, while thirteen orbitals active constructing valence conduction band spectrum, establish that four orbital based minimal basis set sufficient to build Slater-Koster tight-binding model (SK-TB), which capable reproducing bulk surface vicinity Fermi level. Therefore, like Wannier TB model, presented SK-TB can also be considered an tool examine family compounds. As estimated comparing DFT structure, dominant electron coupling strengths found nearly independent XC functionals, further establishes utility model.