Investigating properties of GaSbNBi for optoelectronic applications. An approach employing semi-empirical modelling and Density Functional Theory (DFT)

      Аннотация: This monograph focuses on investigating the impact due to the co-incorporation of N and Bi in GaSb leading to the formation ofGaSb1-x-yNyBix alloy. The condition for lattice matching of GaSb1-x-yNyBix / GaSb is achieved at [N: Bi] ~ 0.14. The study employs semi-empirical model and DFT package for analysis and prediction of the alloy properties. The incorporation of N (Bi) in GaSb leads to the formation of resonant impurity state which interacts with conduction band minimum (valence band maximum), splitting it into sub-band energy levels causing band gap reduction. The structural analysis ofGaSb0.751N0.031Bi0.218 supercell indicates it to be highly stable. The spin-orbit coupling effect is found responsible for uplifting the valence band edge resulting in significant band gap reduction. The analysis of the total density of states claims the spin phenomenon affecting the occupation of electrons at distinct energy states. The analysis of the optical properties is predicted to have higher value of refractive index, reflectivity and extinction coefficient at lower optical band gap. The smoothness of absorption coefficient curve ensures improved optical quality.

Ключевые слова: III-V semiconductors, Density functional theory (DFT), III-V-N-Bi, Anti-crossing Model, VBAC & CBAC, WIEN2K, electronic properties, Optical properties, Lattice Matched, supercell, bandgap, Band offset, Bandstructure