Multiple-component decays of photoluminescence (PL) in InGaN/GaN quantum wells have been widely reported. However, their physical interpretations have not been well discussed yet. Based on wavelength-dependent and temperature-varying time-resolved PL measurements, the mechanism of carrier transport among different levels of localized states (spatially distributed) in such an indium aggregated structure was proposed for interpreting the early-stage fast decay, delayed slow rise, and extended slow decay of PL intensity. Three samples of the same quantum well geometry but different nominal indium contents, and hence different degrees of indium aggregation and carrier localization, were compared. The process of carrier transport was enhanced with a certain amount of thermal energy for overcoming potential barriers between spatially distributed potential minimums. In samples of higher indium contents, more complicated carrier localization potential structures led to enhanced carrier transport activities. Free exciton behaviors of the three samples at high temperatures are consistent with previously reported transmission electron microscopy results.

Based on wavelength-dependent and temperature-varying time-resolved photoluminescence ͑PL͒ measurements, the mechanism of carrier transport among different levels of localized states ͑spatially distributed͒ in an InGaN/GaN quantum well structure was proposed for interpreting the early-stage fast decay, delayed slow rise, and extended slow decay of PL intensity. The process of carrier transport was enhanced with a certain amount of thermal energy for overcoming potential barriers between spatially distributed potential minimums. With carrier supply in the carrier transport process, the extended PL decay time at wavelengths corresponding to deeply localized states can be as large as 80 ns.

Two-component decay of time-resolved photoluminescence (TRPL) intensity in three InGaN/GaN multiple quantum well samples were observed. The first-decay component was attributed to exciton relaxation of free-carrier and localized states; the second-decay one was dominated by the relaxation of localized excitons. The second-decay lifetime was related to the extent of carrier localization or indium aggregation and phase separation. The lifetime of free-carrier states was connected with the defect density. Based on the temperature-dependent data of PL and stimulated emission (SE), the localization energies of the three samples were calibrated to show the consistent trend with the second-decay lifetime and previous material analyses.

We report the fast and slow decay lifetimes of multi-component photoluminescence (PL) intensity decays in the time-resolved photoluminescence measurements at the room temperature and a low temperature (12K). The fast decay component was essentially due to carrier dynamics, that is, carrier transport from weakly localized to localized states. Such a carrier transport process results in extremely long PL decay time (up to almost 120 ns) for strongly localized states at the low temperature. At room temperature, because of thermal energy and hence carrier escape from strongly localized states, effective lifetimes becomes shorter.

We report the fast and slow decay lifetimes of multi-component photoluminescence (PL) intensity decays in the time-resolved photoluminescence measurements at the room temperature and a low temperature. The fast decay component was essentially due to carrier dynamics, that is, carrier flow between strongly localized and weakly localized states. Such a carrier relaxation process results in extremely long PL decay time (up to almost 300 ns) for strongly localized states at the low temperature. At room temperature, because of thermal energy and hence carrier escape from strongly localized states, effective lifetimes becomes shorter.