Cu-doped TiO_2 nanoparticles/graphene composites for efficient dye-sensitized solar cells

摘要

Graphene (GR) demonstrates excellent photoelectrochemical properties, including its large specific surface area, unique structure, chemical stability, high conductance, and fast electron transfer. These parameters are crucial for the performance improvement and photoanode optimization of a dye-sensitized solar cell (DSSC). In this study, Cu-doped TiO2/graphene (CuTGR) composites have been prepared for the first time by the sol-gel-assisted hydrothermal method for the DSSC photoanode application. The prepared CuTGR composites have been coated on Fluorine-doped tin oxide (FTO) glass substrates using the doctor blade method. The surface morphological and elemental analysis reveals the presence of Cu and graphene into CuTGR nanocomposite with uniform distribution and desired morphology. The addition of graphene further improves the dye loading ability of the CuTGR photoanodes with improved current density and faster charge transport as observed in current-voltage (J-V) and intensity-modulated photocurrent spectroscopy (IMPS) measurements. Our findings demonstrate that an optimal loading of Cu and graphene can boost the power conversion efficiency (PCE) of the DSSC (9.81%) by 47% higher than undoped DSSC (6.66%).