Lifetime dispersion in a single quantum dot

We present a decay formula for photoluminescence of a single quantum dot. We apply the formula to time-resolved photoluminescence (PL) measurements for a single InAs/GaAs quantum dot. The formula works very well for the PL decays of excitons and biexcitons in the system. The physical basis of the formula originates from the temporal dispersion of lifetimes.X114sciescopu

A unified decay formula for luminescence decays

We suggest a unified decay formula for luminescence decays in light-emitting diodes by modifying the classical stretched exponential decay. From fundamental considerations we find that the stretched exponent, which is a constant in the classical stretched exponential decay, intrinsically changes with time for luminescence decays. On this basis we develop a unified decay formula by introducing a time-dependent stretched exponent. The time dependence of the stretched exponent is attributed to the lifetime dispersion of localized excitons. (c) 2005 American Institute of Physics.X1176sciescopu

Evolution of luminance by voltage in organic light-emitting diodes

We study degradation behaviors of luminance and voltage in organic light-emitting diodes. We find that normalized luminance and inverse normalized voltage with time, L(t) and V(t)(-1), follow the stretched exponential decay. On this basis, we derive a general relation of luminance and voltage with time as L(t) = V(t)(-delta(t)), where delta(t) indicates a decay exponent, which is attributed to time-dependent space-charge limitation. Here the observation of higher delta(t) at higher initial luminance explains why luminance decay is faster at higher initial luminance. (c) 2006 American Institute of Physics.X1145sciescopu