Optical transitions and recombination lifetimes in GaN and InGaN epilayers, and InGaN/GaN and GaN/AlGaN multiple quantum wells

Time-resolved photoluminescence (PL) has been employed to study the optical transitions and their dynamical processes in GaN and InxGa1-xN epilayers, and InxGa1-xN/GaN and GaN/AlxGa1-xN multiple quantum wells (MQW). We compare the results from both metal-organic chemical vapor deposition (MOCVD) and molecular beam epitaxy (MBE) grown samples. In addition, results are also compared with GaAs/AlxGa1-xAs MQW. It was found for all samples that the low temperature emission lines were dominated by radiative recombination transitions of either localized or free excitons, which demonstrates the high quality and purity of these III-nitride materials.