Electron Transfer Dynamics from Single CdSe/ZnS Quantum Dots to TiO2 Nanoparticles

Electron-transfer dynamics from single CdSe/ZnS (core/shell) QDs to TiO2 nanoparticles were studied. Single QDs on TiO2 showed pronounced and correlated fluctuations of fluorescence intensity and lifetime. Compared to QDs on glass, the presence of the interparticle ET pathway on TiO2 led to smaller on-state and larger off-state probability densities, as well as a shortened lifetime of the on-state. The average electron transfer rate from CdSe/ZnS to TiO2 was estimated to be 3.2 x 10(7) s(-1).