Optoelectronic behaviors and carrier dynamics of individual localized luminescent centers in InGaN quantum-well light emitting diodes

Spatially, spectrally, and temporally resolved photoluminescence (PL) microscopy was performed on InGaN quantum-well light emitting diodes to probe individual localized luminescent centers arising from disorder induced potential fluctuations. Two energetically distinct localization centers were identified where the photoemission quantum-efficiency (QE) are correlated to the transition energies. PL lifetime measurements on emission centers suggest that activation barrier for non-radiative recombination (NR) processes determines their QE. The disparity in carrier dynamics not only substantiate two diverse mechanisms for localization processes, but also indicate the presence of multiple NR channels even within the trap centers implying their lateral dimensions to span several nanometers. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3671092]