Modeling and simulation of optical gain of GaP_0.3Sb_0.7/InP_0.7Sb_0.3 type-II heterostructure for IR optoelectronics under variable well width, temperature and external electric field

Abstract The type-II GaP 0.3 Sb 0.7 /InP 0.7 Sb 0.3 nanoscale heterostructure is modelled and simulated for its optical properties in near-infrared lasing applications. The optical gain of GaP 0.3 Sb 0.7 /InP 0.7 Sb 0.3 type-II heterostructure is analyzed under different external values of electric fields, temperatures and well widths at room temperature 300 K. The complete structure is grown on InP substrate. The effects of a varied temperature (290 K–320 K), quantum well width (2 nm, 3 nm, and 4 nm) and applied electric field (20 kV cm −1 –8 0 kV cm −1 ) are explored regarding the band alignment, wavefunction, band dispersion, matrix elements, gain and wavelength. The Luttinger-Kohn model is utilized to compute the band structure. The gain computation involves the evaluation of the 6 × 6 k·p Hamiltonian matrix. The proposed heterostructure at 2 nm quantum well width exhibits a high optical gain of 14998 cm −1 in x-polarization and 16572 cm −1 in y-polarization for injected carrier concentration of 4 × 10 12 cm 2 . Under variable temperature and electric field, a significant optical gain is achieved in x, y and z input polarizations. This heterostructure is regarded as new because of its very high optical gain in NIR regime, that makes it beneficial for optoelectronics.