Distribution of Photons in Single Quantum Dot Intermittent Photoluminescence with Power-Law Distribution of On/Off Intervals

Abstract

Monte Carlo simulation is used to calculate random time instants of photon emission in single core–shell quantum dot fluorescence with power-law distribution of on and off intervals. Simulation is based on the rate equations which describe a model proposed earlier by the author (JETP Lett.2004, 79, 416) for the quantum dots with many doorways for ionization. After statistical treating of random instants of photon emission, the on/off distributions obeying 1/t1+m law with 0 < m ≤ 0.8 are found. The value of m informs us about the character of the distribution of surface levels in the core and trap levels in the shell near the core–shell interface. Probabilities wN(t) of finding N photons in time interval t in fluorescence with power-law distribution of on and off intervals are calculated for a few values of bin time t. The distribution wN(t) of photon counts in quantum dot photoluminescence with rather intensive fluorescence from so-called “gray states” and with background light is calculated as well. It agrees well with the distribution of counts found in the experiment with blinking fluorescence of CdSe/ZnS single quantum dots.