Doping-induced band edge displacements and band gap narrowing in 3C–, 4H–, 6H–SiC, and Si

Models for doping-induced band edge displacements and band gap narrowing in both n-type and p-type 3C–, 4H–, and 6H–SiC are presented for the first time. For comparison, Si has also been considered. The models constitute an extension of the theory of Jain and Roulston [Solid State Electron. 34, 453 (1991)] and take into account the three different electron effective mass components associated with hexagonal lattices. Furthermore, a more careful treatment of minority carrier correlation energy has been made, applying a two-band model for the dielectric function of a hole gas in the plasmon-pole approximation. The results for the band edge displacements are expressed in simple analytical form as functions of doping concentration.