Air-induced fluorescence bursts from single semiconductor nanocrystals

The photoluminescence intensity of single CdSe/ZnS core/shell nanocrystals which were stabilized by hexadecylamine/trioctyl phosphine/trioctyl phosphine oxide ligands, was studied. Fluorescence was recorded using a homebuilt widefield imaging microscope with a long distance objective lens. A dramatic increase in the fluorescence by a factor of up to 60, was observed, upon sudden purging with air. The results show that reduction in the probability of a prolonged charged period by either minimizing the probability of charging or by enabling rapid decharging, leads to the common power-law behavior of the off-time distribution.