Density of states in hexagonal SiC polytypes

Abstract

Densities of states for the hexagonal polytypes 2H, 4H, and 6H of SiC have been derived for energies within a few hundred meV around the band gaps. The nonparabolic energy dispersions of the valence bands have been taken into consideration, as well as the camel’s back structure of the lowest conduction band in 6H–SiC. The nonparabolicities of the energy bands are shown to strongly influence the densities of states in these polytypes.