CeO2 quantum dot functionalized ZnO nanorods photoanode for DSSC applications

Abstract

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 similar to 5 nm CeO2 QDs were decorated on ZnO NRs having 1-2.5 mu m 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.