ZnO nanobelts as a photoelectrode for dye-sensitized solar cell

Abstract

ZnO nanobelts layer of the dye-sensitized solar cell were prepared by RF sputtered ZnO target onto a copper substrate and characterized by FE-SEM. The structures of solar cells based on ZnO as a photoelectrode, Eosin-Y as a dye sensitizer, iodine/iodide solution as an electrolyte and Pt/TCO as a counterelectrode. The photoelectrochemical characteristics of ZnO DSSCs were tested under simulated sunlight AM 1.5 came from a solar simulator with the radiant power of 100 mW/cm2. It was found that DSSCs based on ZnO nanobelts can generate photocurrent with photoconversion efficiency of 0.6% (JSC = 2.11 mA cm-2, VOC = 0.52, FF = 0.61).The higher JSC in ZnO nanobelt DSSC sample indicates that larger amount of dye adsorbed on surface of ZnO nanobelts than that of ZnO powder. The JSC increases with increasing a thickness of the ZnO photoelectrode for both powder and nanobelt. Moreover, the VOC of ZnO DSSCs is independent on morphology and dye adsorption surface area of ZnO. The obtained photoelectrochemical results can be explained by using energy band diagram.