First-principles study on electronic structure and optical properties of In-doped GaN

The In-doped GaN is investigated by first-principles calculations of plane wave ultra-soft pseudo-potential method based on the density functional theory (DFT). The band structure, electronic structure, density of states and optical properties are investigated. The results indicate that the band-gap becomes narrower and the absorption edge of optical properties is red-shifted with the increase in In-doped concentration. Meanwhile, the visible region has strong absorption properties, and the significant absorption peaks are observed near 3.0 eV and 6.1 eV. The other peaks correspond to the wavelength of absorption spectra from the ultraviolet portion extending to the infrared portion, which almost covers the entire solar spectrum. The studied results show that In-doped GaN can be applied as solar cell and transparent conductivity material.