Photogenerated carrier dynamics in GaN

Summary form only given.A clear understanding of recombination mechanisms is crucial to optimize GaN based III-V semiconductors for optoelectronic devices, especially for consumer applications requiring room temperature operation. For the study of carrier dynamics in optical processes, time resolved photoluminescence (TRPL) represents a powerful tool combining temporal and spectral resolution capabilities. We studied GaN grown by hydride vapor phase epitaxy (HVPE) by TRPL measurements at a variety of optical excitation power levels. We observed a significant increase in the carrier lifetime with increasing excitation power. This is attributed to the saturation of the defect centers associated with the yellow luminescence in GaN.