Few-layered graphene decked with TiO₂ nano particles by ultrasonic assisted synthesis and its dye-sensitized solar cell application

Few-layered graphene (FLG, 1.0, 2.0 and 3.0 wt%)/titania (TiO₂) nanocomposites were prepared by ultrasonic assisted synthesis. The phase and compositional analysis of FLG/TiO₂ nanocomposites were performed with X-ray diffraction and Raman spectroscopy, optical properties carried out by UV–Vis diffuse reflectance spectra and functional groups identified by Fourier transform infrared spectroscopy. Surface morphologies were characterized by field emission scanning electron microscopy and high-resolution transmission electron microscopy. The prepared FLG/TiO₂ nanocomposites were used as working electrodes to form thin films deposited onto fluorine doped tin oxide through a doctor blade technique. The assembled solar cell, current density–voltage characteristics were measured with N719 dye under AM 1.5G, 100 m W/m² of the solar simulator. The efforts showed that the optimized η was observed to be 6.70 % in appropriate with FLG (1.0 wt%)/TiO₂ working electrode, compared to the TiO₂ working electrode. However, by increasing wt% of FLG the η was decreased due to the surface interaction of FLG with TiO₂ NPs. The results revealed that the FLG (1.0 wt%)/TiO₂ working electrode has increased the electron charge transport rate which further leads to enhanced η of DSSC.