Calculation of the band structure, carrier effective mass, and the optical absorption properties of GaSbBi alloys

Abstract

The details of the electronic band structure of GaSbBi as functions of Bi mole fraction and along different symmetry directions of the crystal are calculated using a 14 band k.p model considering the band anti-crossing interaction between the valence band of the host III-V material and the Bi related impurity level resonant with the host. The effect of the lattice strain on the band structure as a result of incorporating a higher amount of Bi in the material is also studied. Variations of the bandgap energy, spin orbit split-off energy, band offsets, and the different sub-band energies are presented as functions of Bi content in GaSbBi as well as along the three symmetric k directions. Effective mass of the charge carriers and their dependence on Bi content is investigated. Furthermore, the intrinsic carrier concentration of the material as a function of Bi composition is evaluated. Finally, the optical absorption in the material is investigated considering the electronic transitions involving various valence sub bands and the conduction band.