Sol–gel derived nanocrystalline ZnO photoanode film for dye sensitized solar cells

Nanocrystalline ZnO was synthesized from zinc (II) acetate/oxalate mixture using a facile sol–gel synthesis and is characterized by techniques such as powder XRD, FTIR and Raman spectroscopy, TEM and SEM. The TEM and SEM study showed that the nanocrystalline ZnO powder and film have an average particle size of 25 nm. This material has been successfully applied as photoanodes in dye sensitized solar cells (DSCs) constructed with standard N719 dye and conventional iodide/triiodide (I−/I3−) electrolytes. A systematic investigation of the performance of DSCs with film thickness and dyeing time had also been carried out. Among the five different film thicknesses 4, 8, 12, 16 and 20 μm prepared, the best result was obtained for the film thickness of 16 μm for 2 h dying showing an efficiency of 2.2% with a JSC of 4.7 mA cm−2 and a very high fill factor of >73%.