Blinking Dynamics: Photoluminenscence Blinking Dynamics of Colloidal Quantum Dots in the Presence of Controlled External Electron Traps (Small 2/2012)

A single-molecule spectroscopy study on colloidal quantum dots reveals the effect of the external charge trap on the photoluminescence blinking dynamics. The study uses a series of colloidal quantum-dot-bridge-fullerene dimers with varying bridge lengths where the fullerene moiety acts as a well-defined, well-positioned external electron trap. A single external electron trap is shown to be able to switch a quantum dot from having “telegraph-like”, two-state on/off blinking behavior into exhibiting quasi- continuous, multistate blinking. Additionally, charge transfer followed by charge recombination is found to be an important mechanism in determining the blinking behavior of isolated quantum dots.