The preparation and characterization of nanostructured TiO2-ZrO2 mixed oxide electrode for efficient dye-sensitized solar cells

The preparation of nanostructured mixed metal oxide based on a sol-gel method with surfactant-assisted mechanism, and its application for dye-sensitized solar cell (DSSC) are reported. The mixed zirconia (ZrO2) and titania (TiO2) mesoporous powder possessed larger surface area than the corresponding titania. For the UV action spectra of unsensitized photochemical cell, the mixed zirconia/titania electrode can absorb UV light below 380 nm, corresponding to band gap (Eg) around 3.27 eV, which is higher than that of pure component of titania (Eg=3.2eV). Both of these improved properties, i.e., BET surface area and band gap, contributed to the improvement on a short-circuit photocurrent up to 11%, an open-circuit voltage up to 4%, and a solar energy conversion efficiency up to 17%, for the DSSC fabricated by mesoporous zirconia/titania mixed system when compared to the cell that was fabricated only by nanostructured TiO2. The cell fabricated by 5 μm thick mixed TiO2-ZrO2 electrode gave the short-circuit photocurrent about 13 mA/cm2, open-circuit voltage about 600 mV and the conversion efficiency 5.4%.