The temperature dependence of optical properties of InGaAsN/GaAs single-quantum wells grown by solid source molecular beam epitaxy (MBE) with N contents varied from 0% to 5.3% was investigated by photoluminescence (PL). The evolution of the peak positions of InGaAs/GaAs sample are in agreement with the empirical Varshni model. However, pronounced temperature-dependent S-shaped peak positions and N-shaped linewidth were observed in PL spectra while increasing nitrogen concentration. The activation energy of InGaAsN/GaAs single quantum well (SQWs) is observed to decrease with nitrogen incorporation, which is contrary to the expectation of the bandgap reduction. This phenomenon suggests that the existence of defect-related nonradiative processes is due to nitrogen incorporation. The results of measurement demonstrate that the nitrogen incorporation into the InGaAsN has strong influence not only on carrier localization but also on the optical quality. In addition, the growth of high nitrogen content (5.3%) shows that the InGaAsN might be the potential candidate for long-wavelength optoelectronic devices. (c) 2006 Elsevier B.V. All rights reserved.