Crystallite structure, surface morphology and optical properties of In2O3–TiO2 composite thin films by sol–gel method

The transparent In2O3–TiO2 composite thin films in nanoscales were prepared via sol–gel method on the float glass substrates, and characterized by X-ray diffraction (XRD), Raman scattering microscopy, atomic force microscopy (AFM), UV–vis spectrophotometer, and Hall-effect testing. It was found that the addition of In2O3 to TiO2 thin films could suppress the grain growth of TiO2 crystals and increase the surface smooth degree, the conductivity, carriers’ concentration and mobility of the as-prepared TiO2 films. The band gap energy of the as-prepared In2O3–TiO2 composite thin films increases from 3.36 eV to 3.44 eV with the increment of In-ingredient in the precursor sols, which provides the potential application of the as-prepared composite thin film using as the anode of the dye-sensitized solar cells to improve the open-circuit voltage.