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

Electron-transfer dynamics from single CdSe/ZnS (core/shell) QDs to TiO(2) nanoparticles were studied. Single QDs on TiO(2) showed pronounced and correlated fluctuations of fluorescence intensity and lifetime. Compared to QDs on glass, the presence of the interparticle ET pathway on TiO(2) 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 TiO(2) was estimated to be 3.2 x 10(7) s(-1).