Optical study of electronic states in GaAsN

GaAs/sub 1-x/N/sub x/ alloys with small N composition (x<1%) and GaAsN/GaAs quantum wells (QWs) were studied by continuous wave photoluminescence (PL), pulse wave excitation PL and time-resolved PL. In the PL spectra an extra transition located at the higher energy side of the commonly reported N-related emissions was observed. By measuring the PL dependence on temperature and excitation power, the new PL peak was identified as a transition of alloy band edge-related recombination in GaAsN and delocalized transition in QWs. The PL dynamics further confirms its intrinsic nature of band edge states rather than N-related bound states.