Stability and Electronic Properties of Silicon-Rich Silicon Carbide Structures

Abstract

The high stability of silicon carbide make it an attractive materials to be used in different applications such as solar cells. Silicon-rich silicon carbide (Si-rich SiC) materials are necessary to tune the band gap for efficient solar light absorptions. Si-rich SiC materials which are thermodynamically stable can be used in solar cell applications without requiring the expensive pure grade silicon or pure grade silicon carbide. Density functional theory (DFT) calculations were used in order to examine different phases of Si-rich SiC to predict stable structures. Since the configurations play a significant role in getting stable results, different configurations of silicon and carbon atoms in Si-rich SiC were considered. The electronic structures were studied, and the total energies were calculated as well as the formation energies. We will present that higher-order hexagonal-phases are more favorable structures than other Si-rich SiC structures due to their more covalent nature of bonding compared to the cubic counterpart.