Introduction: As Electron transport layer (ETL) is one of the important layers in the dye-sensitized solar cells (DSSC) which is responsible for the transport of photo-generated electrons by the dye to the outer circuit. TiO₂ has been widely used as electron transport material in dye-sensitized solar cells. However, improving the light electrical conductivity of TiO₂ without sacrificing the surface area is one of the important strategies to improve the efficiency of the DSSC.

Methods and Results: Here graphene oxide (GO) is added as an additive into the TiO₂ network towards the preparation of TiO₂/reduced graphene oxide (RGO) composites by photocatalytic reduction method. The RGO/TiO₂ composites with different compositions of RGO was characterized and the performance of dye-sensitized solar cells using the prepared material as photoanode was studied. From the XRD and the Raman spectra of the TiO₂ and the TiO₂/RGO composites, the material was found to exhibit anatase phase of TiO₂. Further, the D band and G band peaks of RGO were also observed in Raman spectra. From the UV-VIS absorption spectra, the absorption edge of the TiO₂ nanoparticles was observed to be in the UV region and the TiO₂/RGO composites was found to exhibit absorption tail in the visible region. The carrier lifetime of the TiO₂ and TiO₂/RGO composites was studied using time resolved photoluminescence (TRPL) studies. The HRTEM (high resolution transmission electron microscope) images of prepared TiO₂/RGO composites was found to have sheet like structure surrounding the near spherical nanoparticles, which could be attributed to that of RGO. The binding energy states of the prepared material were studied using X-ray photo electron spectroscopy (XPS) spectra, where C1s was found to exhibit peaks corresponding to C-C, C-OH and C=O bonds.

Conclusions: The incorporation of RGO in TiO₂ was found to improve the BET surface area of TiO₂ and distribution of pores for the TiO₂ and TiO₂/RGO composites was found to be uniform. The DSSC’s were fabricated using the prepared TiO₂ and TiO₂/RGO composites as photoanodes and its power conversion efficiencies were analysed.