Study of the electronic structure of nitrogen doped 3C-SiC with first-principles calculation

The electronic structures of the nitrogen doped(3×3×3)3C-SiC supercell are studied with first-principle calculation in which exchange-correlation energy is indicated by generalized gradient approximation,electronic wave functions are expanded in terms of a plane wave basis set and electron interaction is substituted by a ultra-soft pseudo-potential.The electrical structures of 3C-SiC with different nitrogen doping concentrations are calculated,and results show that the bottom of the conduction band of nitrogen doped 3C-SiC is taken up by N 2s electron states,that the top of the valence band has N 2p electron states,and that the bottom of the conduction band and the top of the valence band shift to a lower energy while the speed of the bottom of the conduction band is faster than that of the top of valence band,which leads to the band gap being narrower with the increase in nitrogen doping concentration.