Blinking Suppression and Anti-Bunching of Quantum Dots as Single-Photon Sources

Abstract

We report here our study on suppression of fluorescence blinking of colloidal CdSe/ZnS quantum dots (QDs) for potential applications as high performance single-photon sources. Blinking is an interesting property for single QDs, but it is undesirable for their applications. We have demonstrated that by coupling these QDs to adjacent silver nanoprisms, we could not only completely suppress the blinking but also enhance the fluorescence quantum yield, and also increase the fluorescence decay rates. These single QDs also exhibit anti-bunching behavior which is a signature for a single-photon emitter. In addition, we have also achieved blinking suppression by embedded the QDs in agarose gel. The electrostatic environment around QDs due to negatively charged fibers of gel might strongly affect the extent of blinking suppression. The mechanisms of blinking suppression will be discussed in the frame work of diffusion-controlled electron transfer model.