Effects of N on Electronic and Mechanical Properties of H-Type SiC

Structural, electronic and mechanical properties of the nH-SiC (n=2, 4, 6, 8 and 10) polytypes are calculated by using the first-principles calculations based on the density-functional theory approach. The optimized lattice parameters of nH-SiC are in good agreement with the experimental data. The mechanical properties, including elastic constants, bulk modulus, Young's modulus, shear modulus and Poisson's ratio, are calculated. The analysis of elastic properties indicates that the effects of n on the mechanical properties of the five nH-SiC structures have no difference. The indirect band gap relationship for the five polytypes is E_bg2H>E_bg4H>E_bg6H>E_bg10H>E_bg8H.