A model for doping-induced band gap narrowing in 3C-, 4H-, and 6H-SiC

We present an analytical model for doping-induced band edge displacements and band gap narrowing in both n-type and p-type 3C-, 4H-, and 6H-SiC. The model is also applied to Si for comparison. The model takes into account details in the band structure dispersion relations both for electrons and holes. Furthermore, the contribution to band gap narrowing from the minority carrier correlation energy has been evaluated explicitly, applying a two-band model for the dielectric function of a hole gas in the plasmon-pole approximation. The results for band edge displacements and band gap narrowing are expressed as simple functions of doping concentration.