Influence of Bi and N related impurity states on the band structure and band offsets of GaSbBiN alloys

The perturbed band structure of a proposed material GaSbBiN, formed by the incorporation of N and Bi in GaSb, is calculated using a 16 band k·p Hamiltonian. The changes in band gap (Eg), spin-orbit splitting energy (ΔSO), conduction band offset (ΔEc) and valence band offset (ΔEv) are investigated as functions of N and Bi mole fractions. In the low temperature regime, the addition of Bi and N to GaSb causes substantial reduction in the band gap and enhances the spin-orbit splitting energy, thereby making Eg < ΔSO which is expected to improve the thermal stability and high-temperature efficiency of photonic devices by the suppression of different loss mechanisms. The values of ΔEc and ΔEv for GaSbBiN alloys, calculated with reference to the host GaSb lattice, increase with the increase in Bi and N concentrations. Calculations indicate that ΔEc > ΔEv which is required for electron confinement in order to get improved temperature-insensitive characteristics of optoelectronic devices.