First-principles Density Functional Theory Calculation of Bulk SnO₂ and Grain Boundaries

SnO₂ has attracted much attention as an electron transport layer in semiconductor devices such as halide perovskite solar cells. In this study, the atomic and electronic structures of SnO₂ were investigated using various exchange-correlation functionals and van der Waals corrections. We also performed both non-self-consistent and self-consistent field calculations using hybrid density functional theory to improve the electronic structure. When six calculation methods were compared, the smaller the lattice constants, the larger the band gap value obtained. The stability of the [120] grain boundary in SnO₂ was also investigated, and different structures could be stabilized depending on the chemical potential of oxygen.