Enhanced photovoltaic performance of dye sensitized solar cell with ZnO nanohoneycombs decorated TiO2 photoanode

Zinc oxide (ZnO) nanohoneycombs were grown on the titanium dioxide (TiO2) layers of the photoanodes for dye sensitized solar cells (DSSC) via hydrothermal method at 93 °C for 5 h and then at 50 °C for 16 h. The photovoltaic performance of TiO2 based DSSCs with ZnO nanohoneycombs decorated photoanodes was investigated. Under the illumination of an air mass 1.5 solar simulator, the short-circuit current density of TiO2 based DSSCs with the decoration of ZnO nanohoneycombs was 21.48 mA/cm2, which was higher than that of TiO2 based DSSCs without the decoration of nanohoneycombs (7.65 mA/cm2). The high specific surface area in ZnO nanohoneycombs enhances the power conversion efficiency (η) of the DSSCs. It is found that the η of the TiO2 based DSSCs is 5.85% in the presence of ZnO nanohoneycomb decoration but only 4.12% in the absence of ZnO nanohoneycomb decoration. The enhanced photovoltaic performance of DSSCs with ZnO nanohoneycombs decorated TiO2 photoanodes can be ascribed to the high specific surface area of ZnO nanohoneycombs and more efficient pathways for electron transportation from the electrolyte to the electrode.