Luminescence mechanisms in quaternary AlxInyGa1−x−yN materials

Abstract

Low-temperature photoluminescence investigations have been carried out in the quaternary AlInGaN epilayers and AlInGaN/AlInGaN multiple quantum wells (MQWs) grown by pulsed metalorganic chemical-vapor deposition (PMOCVD). With increasing excitation power density, the emission peaks in both AlInGaN epilayers and MQWs show a strong blueshift and their linewidths increase. The luminescence of the samples grown by PMOCVD is attributed to recombination of carriers/excitons localized at band-tail states. We also demonstrate the luminescence properties of AlInGaN and AlGaN materials grown by a pulsed atomic-layer epitaxy and conventional MOCVD, respectively.