CeO2 quantum dot functionalized ZnO nanorods photoanode for DSSC applications

Cerium oxide quantum dots (CeO₂ QDs) decorated zinc oxide nanorods (ZnO NRs) heterostructures were grown by a combination of solvothermal and chemical bath deposition methods and used for dye sensitized solar cell (DSSC) applications. Transmission electron microscope images showed the formation of CeO₂/ZnO NRs, where ~5 nm CeO₂ QDs were decorated on ZnO NRs having 1–2.5 μm length and 100–150 nm width. Photoluminescence spectra showed the significant increase in UV emission after decoration of ZnO NRs with CeO₂ QDs. DSSC results revealed that the ZnO NRs with CeO₂ QDs leads to an increase in the open circuit voltage and fill factor and exhibited a maximum efficiency of 2.65 %, which was 2.01 times higher than that of unmodified ZnO NRs. The decoration of CeO₂ QDs on the ZnO NRs surface may lead to the formation of barrier layer and hindered the back electron transfer and thereby high light harvesting efficiency.