Blinking statistics in single semiconductor nanocrystal quantum dots - art. no. 205316

Statistical studies of fluorescence intermittency in single CdSe nanocrysta l quantum dots (QD's) reveal a temperature-independent power-law distributi on in the histogram of on and off times-the time periods before the QD turn s from emitting to nonemitting (bright to dark) and vice versa. Every QD sh ows a similar power-law behavior for the off-time distribution regardless o f temperature, excitation intensity, surface morphology or size. We propose a dynamic model of tunneling between core and trapped charged states to ex plain the universal power-law statistics of the blinking events observed. T he on-time probability distributions show evidence of both a tunneling mech anism similar to the off-time statistics and a secondary, photoinduced proc ess that leads to a truncation of the power law. The same blinking statisti cs are also observed for single CdTe nanocrystal QD's.