Effects of electron beam irradiation on the photoelectrochemical properties of TiO2 film for DSSCs

Abstract

TiO 2 has been widely utilized for various industrial applications such as photochemical cells, photocatalysts, and electrochromic devices. The crystallinity and morphology of TiO 2 films play a significant role in determining the overall efficiency of dye-sensitized solar cells (DSSCs). In this study, the preparation of nanostructured TiO 2 films by electron beam irradiation and their characterization were investigated for the application of DSSCs. TiO 2 films were exposed to 20–100 kGy of electron beam irradiation using 1.14 MeV energy acceleration with a 7.46 mA beam current and 10 kGy/pass dose rates. These samples were characterized using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), and X-ray photoelectron spectroscopy (XPS) analysis. After irradiation, each TiO 2 film was tested as a DSSC. At low doses of electron beam irradiation (20 kGy), the energy conversion efficiency of the film was approximately 4.0% under illumination of simulated sunlight with AM 1.5 G (100 mW/cm 2 ). We found that electron beam irradiation resulted in surface modification of the TiO 2 films, which could explain the observed increase in the conversion efficiency in irradiated versus non-irradiated films. ► The surface of TiO 2 particles was modified by electron beam irradiation. ► The aggregation between each TiO 2 particle was observed in the SEM images. ► Ti 3+ state was enhanced due to the excess electron injection via electron beam irradiation. ► The power conversion efficiency of DSSCs was enhanced.