GASB/INGASB STRAINED-LAYER QUANTUM-WELLS BY MOCVD

The characteristics of GaSb/InGaSb strained quantum wells were studied. The variation of critical layer thickness with In content was calculated using energy balance and mechanical equilibrium models, respectively. The variation of a bulk InGa1-xSb energy-gap was deduced from experimental data. Then the transition energies in the GaSb/InxGa1-xSb single quantum well were calculated using a model which takes into account the elastic strain and quantum well effects. The transition energies from conduction bands to light holes at 12 K were found to be higher than the GaSb energy-gap with In composition below 0.3. Thus, the light hole band cannot be confined in the quantum wells with In composition between 0 and 0.3. The photoluminescence (PL) spectra of quantum well structures with different well widths were presented. The transition energies obtained from the PL spectra were compared with theoretical predictions.