Electronic structure of amorphous indium oxide transparent conductors

Using empirical atomistic simulations and density functional theory (DFT), we examine the atomic and electronic structure of pure- and tin-doped indium oxide in various degrees of amorphisation. Atomic structures ranging from maximally amorphous (within fixed periodic boundary conditions) to fully crystalline are prepared using liquid-quench molecular dynamics simulations in which the cooling/quench rate is the governing parameter. The final structures are reoptimized using DFT and the electronic structure (band gaps and carrier effective masses) are compared to the crystalline material. We find that the conduction bands of In₂O₃ are quite resilient in several aspects to changes in the atomic structure. This suggests that local coordination geometries around indium and oxygen are less critical to transparent conductivity than previously thought.