Various photoluminescence properties due to Γ–X resonance in type-I GaAs/AlAs multi-quantum wells consisting of quantum wells with different thicknesses

The electric-field dependence of photoluminescence (PL) spectra in a GaAs/AlAs multi-quantum well (MQW) was investigated, in which QWs with different thicknesses are casually contained. PL spectra reveal various properties due to the combination effect of interface roughness and Γ–X scattering even in type-I band configuration. A PL signal caused by LO-phonon-assisted carrier relaxation between first excited states (Γ2 states) having different energy values due to different QW thickness was also observed. The observation of PL signals from excited states in MQW provides fruitful information on carrier injection into excited states due to Γ–X scattering and structural imperfection of MQWs.