Computation of Electronic and Optical Properties of GaAsNSb with 16 Band k dot p Model

Abstract

The electronic band structure (BS) and optical gain have been calculated for GaAs_1−x−yN_xSb_y/GaAs alloys by combining two Band Anticrossing (BAC) Models for Conduction Band and Valence Band i.e. CBAC and VBAC under k·p formalism. This mathematical model based on a 16 × 16 Hamiltonian matrix is used to compute the anticrossing interactions between the sub bands for variable Sb and N concentration in GaAsNSb/GaAs. The effect of Sb and N related impurity levels in GaAsNSb/GaAs on the band gap, carrier effective masses, spin-orbit splitting energy, band offsets and their ratios are also investigated. It has been shown that band gap shrinks by ~330 meV for Sb and N concentration of 5 and 1.9 at% respectively. The concentration dependent band gap reduction and the enhancement of spin-orbit splitting energy results in the origin of a Δ_so > E_g regime which forms the basis for the suppressing Auger recombination mechanisms in III–V LASERs. We have also investigated the variation of optical gain for different injected surface carrier densities and carrier confinement assists the optical gain to reach 1400/cm⁻¹ near 1.2 eV window.