Electrical and optical properties of graphene-TiO2 nanocomposite and its applications in dye sensitized solar cells (DSSC)

In the present investigation graphene-TiO2 (Gr-TiO2) nanocomposites were synthesized with different graphene concentrations. Graphene nanoparticles were synthesized using modified hummers method, TiO2 nanoparticles were purchased from Sigma Aldrich. It was observed that band gap was reduced from 3.16 eV to 2.2 eV with the increase in graphene concentration. Moreover, conductivity increases with graphene concentration which corroborates well with the reduction in band gap. Gr -TiO2 nanocomposites were used as photo anode of DSSCs. Photoelectrical conversion efficiency of DSSC was improved with the introduction of graphene and optimum results were obtained for 3.0 wt percent of graphene concentration.