Photoluminescence thermal-quenching and carrier localization of AlGaAs disordered superlattices

Thermal quenching properties of disordered superlattices (d-SLs) are experimentally investigated. Three types of d-SLs with (1) various band-gap differences, (2) various unit lengths of disorder, and (3) various appearance probabilities of disordered layers are used for experiments. Thermal quenching properties of photoluminescence intensities are investigated for the estimation of strength of disorder. Consistent results are obtained in that the thermal quenching becomes small with increasing disorder for each type of d-SL. Abrupt changes in the thermal quenching characteristics are observed at the type-I/type-II transitions of AlyGa1−yAs/GaAs d-SLs and o-SLs.