A comparative study on the influence of pure anatase and Degussa-P25 TiO2 nanomaterials on the structural and optical properties of dye sensitized solar cell (DSSC) photoanode

In this paper, two different nanomaterials of pure anatase and Degussa-P25 TiO2 based dye sensitized solar cells (DSSCs) photoanode were fabricated and characterized to investigate the influence of the nanomaterials and the natural dye on various optical and structural parameters of the photoanodes. Adsorption of dye showed remarkable changes on the various structural parameters including crystallite size, strain, morphology index (MI), specific surface area (SSA), dislocation density, and crystallites per unit surface area (CPSA) for both the Degussa-P25 and pure anatase TiO2 samples analysed by X-ray diffraction (XRD). In UV-vis-NIR spectroscopic optical studies for the dye-adsorbed samples, the overall light absorption was found to decrease for both the anatase and Degussa-P25 from UV to NIR. On the other hand, the dye-free samples were found to exhibit a lower light absorption from UV to green and beyond that level, absorption showed higher value than the dye adsorbed samples. Among the dye-free and dye-adsorbed samples, absorption depth was observed to increase more with the increasingly incident light wavelength for all the dye-adsorbed than the dye-free samples. Optical band gaps were found to decrease from 3.1 eV to 2.95 eV and 3 eV to 2.83 eV for dye-free and dye-adsorbed samples of Degussa-P25 and pure anatase, respectively.