Optical transitions in GaN/AlxGa1−xN multiple quantum wells grown by molecular beam epitaxy

Time-resolved photoluminescence was employed to study optical transitions in GaN/AlxGa1−xN multiple quantum wells (MQWs). The effects of quantum confinement on the optical transitions as well as on the exciton-phonon interactions in MQW were investigated. Recombination lifetimes of optical transitions were measured at different emission energies and temperatures from 10 to 300 K. It was found that the exciton recombination lifetime increases linearly with temperature up to 60 K, which is a hallmark of radiative exciton recombination in MQW. Observed optical transitions and their dynamics in GaN/AlxGa1−xN MQW were also compared with those in GaN epilayers and GaAs/ AlxGa1−xAs MQW.