Dye-Sensitized Solar Cell Based on TiO2-Graphene Composite Electrodes

Dye-sensitized solar cells(DSSCs) based on TiO2 film photo anode incorporated with different amount of grapheme nanosheet(GNS) are fabricated and their photovoltaic performance are investigated. The TiO2-GNS compos- ite electrode has been prepared by a direct mixing method. The DSSC performance of this composite electrode was mea- sured using N3 dye as a sensitizer. The performance of DSSCs using the TiO2-GNS composite electrodes is dependent on the GNS loading in the electrodes. The results show that the DSSCs incorporating 0.01 wt% GNS in TiO2photo anode demonstrates a maximum power conversion efficiency of 5.73%, 26% higher than that without GNS. The per- formance improvement is ascribed to increased N3 dye adsorption, the reduction of electron recombination and back transport reaction as well as enhancement of electron transport with the introduction of GNS. The presence of both TiO2 (anatase) and GNS has been confirmed by FieldEmission Scanning Electron Microscopy(FE-SEM). The decrease in recombination due to GNS in DSSCs has been investigated by the Electrochemical Impedance Spectroscopy.