Density functional theory capture of electronic structures and optical properties of vacancy doped 3C-SiC systems

Abstract

Using a first principles calculation we investigate the electronic structures and optical properties of vacancy doped 3C-SiC systems. It is found that the C vacancy doping 3C-SiC has most considerable stability compared to that doped by Si vacancy when the Schottky defect occurs. The energy band density increases after doping and some impurity levels appear near the Fermi level, which may increase the carrier concentration and electronic intraband or interband transition. The charge-difference density maps show that the covalent order of bonding is VSi-VSi > VSi > pristine > VC > VC-VC. For the VSi doped system, the static dielectric constant of increases to 21.581 and the imaginary part raises remarkably, demonstrating its potential applications in the fields of aerospace applications. Simultaneously, a ‘blue shift’ phenomenon can be observed for the doping systems. The systems exhibit strong absorption and reflection capacities in the range of 5–10 eV before and after doping, showing the ‘Barrier Type’ feature. The host peak values of the L(ω) in the doped systems are lower, presenting the feature of the semiconductors.