Abstract
There has been investigated the effect of post-growth-annealing-induced interdiffusion process, and hence interface intermixing, on the electronic structure of $Ga_{0.35}In_{0.65}As_{0.32}Sb_{0.68}/Al_{0.25}Ga_{0.50}In_{0.25}As_{0.24}Sb_{0.76}$ single quantum well designed to emit light in the range of about 3 µm. The band structure and optical transitions have been calculated based on the single band effective mass model and Fick's interdiffusion law. The calculation results are consistent with the experimentally observed transitions obtained by employing modulation spectroscopy. Our studies indicate that the intermixing processes in this kind of quantum wells are predominantly induced by the interdiffusion of group III atoms. The derived effective diffusion coefficient has been estimated to be of the order of $10^{-21} m^{2} s^{-1}$ for 480 °C annealing temperature.