Synthesis and Optical Properties of Linker-Free TiO2/CdSe Nanorods

Linker-free TiO2/CdSe hybrid nanorods (NRs) were prepared by growing CdSe QDs in the presence of TiO2 NR seeds using seeded–growth type colloidal injection approach. TEM studies revealed the abundant formation of anatase TiO2 NRs with different lengths. We found that the as-prepared TiO2 seeds determined the morphology of TiO2/CdSe NRs. The photophysics of these materials were studied by photoluminescence (PL) and femtosecond transient absorption spectroscopy. While we observed the efficient PL quenching in TiO2/CdSe NRs, the bleach dynamics of TiO2/CdSe NRs is similar to that of CdSe NRs. It suggests that while surface traps that arise from the lattice mismatch between CdSe and TiO2 are mainly observed in transient absorption measurements the ultrafast exciton dissociation over the experimental time resolution occurs in TiO2/CdSe NRs.