PHONON BOTTLENECK IN SELF-FORMED INXGA1-XAS GAAS QUANTUM DOTS BY ELECTROLUMINESCENCE AND TIME-RESOLVED PHOTOLUMINESCENCE/

We demonstrate experimentally that a photon bottleneck for carrier rel axation does exist in self-formed InxGa1-xAs/GaAs quantum dots. With t ime-resolved photoluminescence, we measured the carrier relaxation lif etime and radiative recombination lifetime in five discrete levels as a function of temperature. We found that the higher the temperature an d the level were, the shorter the relaxation lifetime was (1 ns-10 ps) . The radiative recombination lifetime measured was about 1 ns and was found to be independent of temperature. We also simulated electrolumi nescence spectra at 77 and 300 K with the measured lifetimes. We found that the first, second, and third levels could not be fully filled wi th injected carriers.