Oxygen ion-beam irradiation of TiO2 films reduces oxygen vacancies and improves performance of dye-sensitized solar cells

摘要

Oxygen vacancy-related surface defects on porous TiO_2 films were reduced by oxygen ion-beam treatment, and the effect of such defects on the performance of dye-sensitized solar cells was examined. An oxygen ion-beam treatment of a TiO_2 film caused a significant decrease in particle agglomeration and an increase in surface area of the resulting TiO_2 film. In addition, the increased hydrophilicity of the TiO_2 film by the ion beam treatment led to an increase in dye adsorption. The oxygen ion beam treatment at 500 and 1000 eV caused a significant decrease in oxygen vacancies and increase in the open-circuit voltage (V_(oc)). Oxygen ion beam-treated TiO_2 film electrodes showed the maximum solar-to-electricity conversion efficiency (η%) of 8.04% compared to the 6.15% obtained from an untreated TiO_2 electrode.