Probing dynamics of photoinduced charge transfer in heterodimers composed of CdSe/ZnS quantum dots and fullerene derivatives by single molecule spectroscopy

Photo-induced charge transfer in heterodimers composed of CdSe/ZnS semiconductor quantum dot and fullerene was probed by single molecule fluorescence spectroscopy by using quntum dots of various colors and interparticle linkers with varying distance. Quenching of single quantum dot's photoluminescence by charge transfer was observed only in the "on" state and it manifests both as a reduced fluorescence intensity and as a shortening in fluorescence lifetime. As a result, the charge transfer changes the on/off dynamics (blinking) of the fluorescence intensity of individual quantum dots. The results obtained in these studies will be discussed in view of the use of such heterodimers in solar energy applications.