We have studied the effects of interactions with cyclic solvent molecules on the optical dephasing of CdSe/ZnS colloidal quantum dots (QDs) by femtosecond four-wave mixing spectroscopy. We have found that the interactions with the cyclic solvents without π-bonds result in unexpectedly long dephasing times of QDs even at room temperature, while the interactions with the cyclic solvents including π-bonds make the optical dephasing of QDs extremely fast with a dephasing time of less than our time resolution.

Abstract:We studied dynamic interactions between CdSe/ZnS quantum dots (QDs) and cyclic solvents probed by femtosecond four-wave mixing. We found that the dynamic interactions of QDs strongly depend on the existence of π-bonds in solvent molecules.