Density functional theory study on electronic structure of N-doped In2O3

Density functional theory (DFT) calculations are used to characterize the doping effect of N substitution of O in hexagonal In2O3 and N occupying vacant anion site of cubic In2O3. The results show that in both N-doped systems localized N 2p states are principally formed above the top of the O 2p valence band, leading to the reduction of the photon transition energy, and the redshifts of the absorption edge. When the doping level rises, the energy gap has little further narrowing compared with that at lower doping concentrations, and the larger formation energies are required for the synthesis of two polymorphs N-doped In2O3.