Influence of Rapid Thermal Annealing on Carrier Dynamics in GaInNAs/GaAs Multiple Quantum Wells

The excitation intensity and time-resolved photoluminescence spectroscopy are used to investigate the impact of annealing on the carrier dynamics in the Ga_0.66In_0.34N_0.013As_0.987/GaAs multiple quantum well structure grown by metalorganic chemical vapor deposition. The measurement of excitation intensity photoluminescence (PL), performed for as-grown and annealed samples at different temperatures, indicates that the localized potential has come down slightly after annealing but does not alter the fact that PL emission at low temperature is dominated by localized exciton recombination. In contrast, free carrier recombination is magnified by post-grown annealing at room temperature. Our results show that the decay times are 0.587 and 0.327 ns at 10 K for the as-grown and annealed samples, and radiative decay times also shorten significantly after annealing at all temperatures. Hence the improvement of luminescence efficiency after annealing is caused by the reduction of localization and enhancement of radiative recombination rate. The reduction of the density of nonradiative centers is demonstrated indirectly after annealing.