摘要： Band structures of Si-C and Si-C-Ge alloys are calculated by using the ab initio LMTO (linear muffin-tin orbital) method within the framework of atomic-sphere approximation. The effects of different atomic configuration and lattice relaxation on the band structure of alloys are taken into account. The results show that for large concentrations of C in Si and Si-Ge, the band gap increases monotonically, while for small concentrations of C in Si and Si-Ge, the band gap shrinks. The lattice relaxation further reduces the band gap. The possible explanations for the reduction of band gap of Si-C and Si-C-Ge alloya are presented.

Abstract: Band structures of Si-C and Si-C-Ge alloys are calculated by using the ab initio LMTO (linear muffin-tin orbital) method within the framework of atomic-sphere approximation. The effects of different atomic configuration and lattice relaxation on the band structure of alloys are taken into account. The results show that for large concentrations of C in Si and Si-Ge, the band gap increases monotonically, while for small concentrations of C in Si and Si-Ge, the band gap shrinks. The lattice relaxation further reduces the band gap. The possible explanations for the reduction of band gap of Si-C and Si-C-Ge alloya are presented.

中图分类号:  (Semiconductor compounds)

• 71.20.Nr

71.15.Ap (Basis sets (LCAO, plane-wave, APW, etc.) and related methodology (scattering methods, ASA, linearized methods, etc.))