Suppression of grey state and optimization of the single photon emission of a colloidal semiconductor at room temperature

摘要

The excitation energy dependency of single colloidal CdSe-CdS core-shell nanocrystals is investigated at ambient conditions. It was demonstrated that the photoluminescence blinking effect is totally suppressed by optically exciting nanocrystals with a laser wavelength located at a very low absorption spectrum range. The mechanism of this effect is theoretically attributed to excitation of only the core instead of both the core and the shell. The signal to noise ratio and the photon count are also significantly improved and better purity in terms of single photon generation is achieved. Published by AIP Publishing.