Electronic Structure Analysis of C:Si Codoping AlN Crystals
The band structure and electronic properties of 32-atom wurtzite AlN supercell system with C∶Si codoping is investigated by the full-potential linearized augmented plane wave method( FP-LAPW)based on the Density Functional theory( DFT). If the concentration of doped C atoms is equal with that of Si atoms,C-Si complexes will be formed,but for the compensation effects,the concentration of free carriers will be very low; as the concentration of C atoms is increased,other complexes,such as C2-Si,C3-Si etc.,will be formed. The existence of these complexes can increase the solubility of acceptor impurities as well as reducing their activation energy. It is found that C∶ Si codoping is a promising way to gain p-type AlN crystals.