Structural, elastic and electronic properties of 2H- and 4H-SiC

The structural, five different elastic constants and electronic properties of 2Hand 4H-Silicon carbide (SiC) are investigated by using density functional theory (DFT). The total energies of primitive cells of 2Hand 4H-SiC phases are close to each other and moreover satisfy the condition E2H >E4H . Thus, the 4H-SiC structure appears to be more stable than the 2Hone. The analysis of elastic properties also indicates that the 4H-SiC polytype is stiffer than the 2H structures. The electronic energy bands, the total density of states (DOS) are calculated. The fully relaxed and isotropic bulk modulus is also estimated. The implication of the comparison of our results with the existing experimental and theoretical studies is made.