Nanostructured TiO2 thin films by chemical bath deposition method for high photoelectrochemical performance

TiO2 thin films were deposited by simple chemical bath deposition method onto conducting and non-conducting glass substrates. The resulting films were annealed at 300°, 400°, and 500 °C for 3 h. In XRD studies, crystallite size and microstrain from x-ray line broadening profile were estimated by Scherrer's and Williamson-Hall plot method. Also, structural parameters such as unit cell volume, lattice constants, dislocation density, and stacking fault probability have been calculated. Optical absorption spectra illustrate that the band gap energy has been decreased from 3.45 to 3.19 eV with increasing annealed temperatures. Furthermore, the photoluminescence (PL) spectra exhibited two luminescence centers, one is for near-band-edge emission (NBE) and another is for deep level emission (DLE). From FT-IR spectrum of 400 °C annealed film, it was found that strong band around at 609 cm−1 is associated with the characteristic vibrational mode of anatase TiO2. The morphology and elemental composition of the 400 °C annealed film were investigated by field emission scanning electron microscopy (FESEM) and energy dispersive x-ray (EDS) analysis respectively. Present work deals with a significant photoelectrochemical cell performance of TiO2 thin films annealed at 400 °C and explored the cell parameters like conversion efficiency (η) and fill factor (FF). Finally, it was found that the deposited TiO2 films showed the outstanding PEC performance with supreme photoconversion efficiency 1.94%.