Urea treated WO 3 and SnO 2 as cost effective and efficient counter electrodes of dye sensitized solar cells
27-12-2017 19:19
Commercial electrocatalytically inactive metal oxide such as WO3, SnO2 and ZnO were successfully transformed to highly electro catalytic active material toward iodide/triiodide electrolyte and have been used as efficient counter electrodes for due sensitized solar cell. The significant improvement was performed by treating the metal oxides with urea before annealing in N2 environment. The introduction of oxygen vacancies into metal oxides facilitates the charge transfer at metal oxide/ electrolyte interface. Treating with urea could control the oxygen vacancies density inside metal oxide by varying urea concentration in in metal oxides. With a specific optimum concentration of urea, we can get the optimum overall performance of metal oxides as counter electrode. All experimental characterization performed support this hypothesis and metal oxides counter electrodes were successfully made and the device overall power conversion efficiency was comparable to those with Pt counter electrode.