Optical gain enhancement and wavefunction confinement tuning in AlSb/InGaAsP/GaAsSb heterostructures

The results from self-consistent k · p computation of optical gain characteristics of AlSb/InGaAsP/GaAsSb type-II ultra-thin quantum-well heterostructures show a marked improvement in optical gain as compared to the InGaAsP/GaAsSb type-II ultra-thin quantum well heterostructures. The AlSb/InGaAsP/GaAsSb type-II ultra-thin quantum well heterostructures were designed to obtain enhanced optical gain as compared to InGaAsP/GaAsSb type-II quantum well heterostructures. An improvement in optical gain of 948 cm - 1 and a shift in peak energy of 0.03 eV is attributed to interband resonant tunnelling effect and the band alignment due to the presence of GaAsSb layer. Also, a narrower optical gain spectrum is observed in AlSb / In 0.5 Ga 0.5 As 0.8 P 0.2 / Ga As 0.5 Sb 0.5 QW heterostructure as compared to the In 0.5 Ga 0.5 As 0.8 P 0.2 / Ga As 0.5 Sb 0.5 QW heterostructures. Furthermore, the effect of variation in well width has been studied at AlSb layer thickness 1 nm for optical gain enhancement and wavefunction confinement where the resonant tunnelling effect is observed. Graphic Abstract Fig. Optical gain in A l S b / In 0.5 Ga 0.5 As 0.8 P 0.2 / G a As 0.5 Sb 0.5 heterostructures