Model for power-law statistics in blinking photoluminescence of single semiconductor nanocrystals

A simple physical model for single semiconductor nanocrystals (NCs) with statistics for blinking fluorescence following 1/t1 + m power law is proposed. The model takes into account e-h pairs of NC localized near surface of NC and traps localized in the shell material near surface of NC. Ionization of NC is realized via jth localized electronic state near surface of NC. The exponent m in the power law is connected with the sharpness of the distribution function for the localized electronic states situated near surface of NC and with the sharpness of the distribution function for the traps in the shell material. Values m ranging from 0.5 to 0.7 found in experiments correspond to high degree of localization of the distribution function for both e-h pairs and traps near boundary between NC and the shell material.