Electronic band structure and effective masses of electrons and holes in the α and β phases of silicon nitride

Abstract

The electronic band structure of the two main crystallographic modifications of silicon nitride, namely, the α-Si3N4 and β-Si3N4 phases, is calculated from the first principles. The estimates obtained for the effective charges of silicon and nitrogen atoms and those for the effective masses of electrons and holes in the α-Si3N4 phase are in good agreement with the available experimental data for amorphous silicon nitride a-Si3N4. The calculations performed demonstrate that the effective mass tensor determined for the β-Si3N4 phase differs substantially from the effective mass tensor obtained for the α-Si3N4 phase.