Effect of TiO2 dense film prepared by long-throw RF sputtering on the performance of dye-sensitized solar cell

Graded index TiO₂ dense film that can improve transmittance is employed at the interface between the indium-tin-oxide (ITO) and nanocrystalline-TiO₂ by radio-frequency magnetron sputtering. The employment of the d-TiO₂ film in the dye sensitized solar cell was investigated by means of optical properties (UV-absorption and transmittance spectra) and open-circuit voltage decay (OCVD). The blue-shift of the UV-absorption spectra and lower series resistance value of the dry cell implied the decrease of the charge interfacial resistance, and thus facilitating the charge transport from the nanocrystalline-TiO₂ to the ITO. Furthermore, the higher conversion efficiency of about 4.38%, representing almost 53% increment compared to bare ITO cell is mainly due to the effectiveness of blocking effect and better spectral management across the interfaces in the DSSC. These integrated features became desirable traits brought about by the application of the ITO/d-TiO₂ for use in dense film-based DSSC applications. This work also provides the fundamental insight of the dense film that determines the origin of such improvement in the DSSC performance.