Enhanced performances of dye-sensitized solar cells based on graphite–TiO2 composites

The graphite-incorporated TiO2 composites for the photoanodes of the Dye-sensitized solar cells were prepared by ultrasound-assisted mixing method. The performances of these solar cells with different graphite additions were investigated by the photocurrent-voltage characteristics, open-circuit voltage decay measurement and electrochemical impedance spectroscopy. The results showed that the addition of graphite had a significant impact on the electron transport and recombination. The photocurrent-voltage results indicated that short-circuit current density (Jsc) and open-circuit voltage (Voc) enhanced by 40% and 2%, respectively. A 30% improvement in conversion efficiency of dye-sensitized solar cell from 4.44% to 5.76% was achieved using 0.01 wt% graphite–TiO2 composite electrodes compared to the pure TiO2 electrode.