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

The results from self-consistent $$k\cdot p $$ 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 $${cm}^{-1}$$ 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 $$\mathrm {AlSb/}{\mathrm {In}}_{{0.5}}{\mathrm {Ga}}_{{0.5}}{\mathrm {As}}_{{0.8}}\mathrm {P}_{{0.2}}\mathrm {/Ga}{\mathrm {As}}_{{0.5}}{\mathrm {Sb}}_{{0.5}}$$ 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 $${\mathrm {In}}_{{0.5}}{\mathrm {Ga}}_{{0.5}}{\mathrm {As}}_{{0.8}}\mathrm {P}_{{0.2}}\mathrm {/Ga}{\mathrm {As}}_{{0.5}}{\mathrm {Sb}}_{{0.5}}$$ 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 $${AlSb/}{{In}}_{{0.5}}{{Ga}}_{{0.5}}{{As}}_{{0.8}}{P}_{{0.2}}{/Ga}{{As}}_{{0.5}}{{Sb}}_{{0.5}}$$ 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