Facile synthesis of highly branched jacks-like ZnO nanorods and their applications in dye-sensitized solar cells

Highly branched, jacks-like ZnO nanorods architecture were explored as a photoanode in dye-sensitized solar cells, and their photovoltaic performance was compared with that of branch-free ZnO nanorods photoanodes. The highly branched network and large pores of the jacks-like ZnO nanorods electrodes enhances the charge transport, and electrolyte penetration. Thus, the jacks-like ZnO nanorods DSSCs render a higher conversion efficiency of eta = 1.82% (V(oc) = 0.59 V. J(sc) = 5.52 mA cm(-2)) than that of the branch-free ZnO nanorods electrodes (eta = 1.08%, V(oc) = 0.49 V, J(sc) = 4.02 mA cm(-2)). The incident photon-to-current conversion efficiency measurements reveal that the jacks-like ZnO nanorods DSSCs exhibit higher internal quantum efficiency (similar to 59.1%) than do the branch-free ZnO nanorods DSSC (similar to 52.5%). The charge transfer resistances at the ZnO/dye/electrolyte interfaces investigated using electrochemical impedance spectroscopy showed that the jacks-like ZnO nanorods DSSC had high charge transfer resistance and a slightly longer electron lifetime, thus improving the solar-cell performance. (c) 2011 Elsevier Ltd. All rights reserved.