Effect of TiO2–graphene nanocomposite photoanode on dye-sensitized solar cell performance

In this research work, graphene–TiO2 photoanodes with various graphene concentrations (0, 0.5, 1, 1.5 and 2 wt%) were deposited on fluorine tin oxide glass substrates as working electrodes for dyesensitized solar cells. The structure, morphology, surface composition and dye adsorption of the photoanodes were investigated by X-ray diffraction, field emission scanning electron microscopy, X-ray photoelectron spectroscopy and UV–VIS–NIR spectroscopy, respectively. The photocurrent–voltage characteristics of the dye-sensitized solar cells were examined using a solar simulator. The results indicated that the dye adsorption on photoanode surfaces increases with the increase in the graphene content. In addition, dye-sensitized solar cells efficiency increases with the increase in the graphene content to 1.5 wt% and then decreased. The efficiency of the dyesensitized solar cell, based on the TiO2–1.5 wt% graphene nanocomposite, increased by 42% with respect to the pristine sample.