Characterizing the role of Li ion insertion in to ZnO nanostructures in improving photovoltaic performance of dye-sensitized solar cells.

Despite high electron mobility of ZnO nanocrystalline particles than that of TiO 2 nanocrystaline particle, the power conversion efficiency of ZnO based DSSCs photoelectrode is inferior to that of TiO 2 based photoelectrode. Li ion insertion in to ZnO enhances the power conversion efficiency due to enhancement of  short-circuit current density (J sc ), open circuit voltage (V oc ) and fill factor (FF). A record Voc of 764 mV and  a record FF of 74.% were obtained for Li incorporated ZnO nanoparticle photoanodes.  Li ion incorporation found to improves charge transport and suppress the recombination. Optimum concentration of Li ion is 1% (w/w) and with further increase of Li ion reduces the solar cell performance.