Zinc oxide precursor treatment for improving dye‐sensitized solar cell efficiency

Unlike TiO2-based dye-sensitized solar cells (DSSCs) where improvements in the efficiency with TiCl4 treatments are well established, there are no known treatments to improve the efficiency of ZnO-based DSSCs. Here we investigated treatments (solution-based, followed by annealing) with different ZnO precursors (zinc acetate, zinc chloride, and zinc nitrate) on the properties of ZnO porous film and on the ZnO-based DSSC performance. While zinc chloride and zinc acetate treatments do not improve DSSC performance, zinc nitrate treatment results in increased orange-red defect emission of ZnO electrode, significant difference in the impedance characteristics, and improved photovoltaic performance from 2.07% to 2.35% with ∼12% increase in power conversion efficiency compared to untreated cells.