Structural stability, electronic and optical properties of Ni-doped 3C-SiC by first principles calculation

Structural stability along with the electronic and the optical properties of intrinsic 3C-SiC and Ni-doped 3C-SiC were studied by the first principles calculation. For the Ni-doped 3C-SiC, substitution of Ni in Si sub-lattice is energetically more favorable than that in C sub-lattice. Some new impurity energy levels appear in the band gap of Ni-doped 3C-SiC, which can improve the conductivity of 3C-SiC. The imaginary part of the dielectric function of Ni-doped 3C-SiC has three remarkable peaks at 0.69 eV, 2.35 eV, and 4.16 eV. This reveals that doping with Ni can improve the photo-absorption efficiency of 3C-SiC. In the absorption spectrum of Ni-doped 3C-SiC, the absorption edge red-shifts towards the far-infrared region. Furthermore, three new absorbing peaks emerge in the near-infrared region, visible region, and middle-ultraviolet region. These features confer Ni-doped 3C-SiC qualifications of a promising optical material.