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In this study, nano-TiO2 thin film electrode and solar cell have been investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet–visible absorption spectra, contact angle, X-ray photoelectron spectroscopy (XPS), and current–voltage characteristics analyses. X-ray diffraction patterns show that the best sintering temperature of a nano-TiO2 film is 600 °C, at which TiO2 anatase phase forms best and the particle size of 8–10 nm can be obtained. The SEM images of a nano-TiO2 thin film show that the surface of the film is smooth and porous, and the thickness of the nano-TiO2 film is 4 μm. The measurements of contact angle between nano-TiO2 film and deionized water (DI water) reveal that the nano-TiO2 film is super-hydrophilic when solarized under ultraviolet. The electrode of dye-sensitized solar cell is used as a free-base porphyrin with carboxyl group, 5,10,15,20-tetrakis (4-carboxyphenyl) porphyrin (TCPP) as the sensitizer to adsorb onto the TiO2 thin film. From the results of ultraviolet–visible absorption spectra and XPS analyses of the electrode, the effects of nano-TiO2 particles’ addition to the electrode of dye-sensitized solar cell can improve the absorption of visible light (400–700 nm) and increase electrons transferred from TCPP to the conduction band of TiO2, resulting in the enhancement of efficiency for dye-sensitized solar cells. |
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