Electronic and optical properties of Co-doped 3C-SiC from density functional calculations

Structural properties along with the electronic and optical properties of intrinsic 3C-SiC and Co doped 3C-SiC are calculated using the first principles method based on the density functional theory. The calculated results show that the Fermi level locates at the valence band maximum in the pure 3C-SiC, while it shifts to the conduction band and exhibits metal-like characteristic after Co atoms are introduced into the SiC supercell. The calculated electronic structures indicate that the number of the energy levels in upper valence band substantially increased after Co doping, which is attributed to the Co-3d states. The optical property calculation suggests that the intensity of the photoluminescence (PL) spectrum is determined by the bandgap and the location of PL peak is associated with the optical absorption.