FIRST-PRINCIPLES STUDY OF ELECTRONIC AND OPTICAL PROPERTIES OF Mn-DOPED 3C-SiC FILMS

The electronic and optical properties of Mn-doped 3C-SiC films are investigated by the first-principles calculation. The structure of Mn-doped 3C-SiC is modeled by substituting Mn atom for C or Si atom in 3C-SiC lattice. The results suggest that Mn-C and Mn-Si bonds can exist in the Mn-doped 3C-SiC. Mn location in 3C-SiC lattice significantly affects the crystal structure of Mn-doped 3C-SiC, and the Mn atom substitution for C or Si sites of 3C-SiC lattice can induce to the difference of indirect or direct band structure. The calculated results also show that some new impurity energy levels occur in the band gap of Mn-doped 3C-SiC, and the imaginary part of dielectric function of Mn-doped 3C-SiC shifts toward the infrared region in comparison with the primitive 3C-SiC. The adsorption spectrum of Mn-doping 3C-SiC, due to the transition of electrons between Mn 3d states, presents some new prominent peaks at low frequency. These results can further confirm Mn-doped 3C-SiC to act as a potential material for optical applications.