BaTiO₃-coated TiO₂ working electrodes for use in dye-sensitised solar cells

Nanostructured TiO₂ working electrodes were coated with thin films of BaTiO₃ using the sol-gel technique. These core-shell electrodes were made and compared against the control samples (bare TiO₂). The electrodes were characterized using scanning electron microscopy (SEM), energy dispersive X-ray Spectroscopy (EDX), powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy and used in the construction of dye-sensitised solar cells (DSSCs). It was found that all the BaTiO₃-coated samples resulted in an increase in the open circuit voltage (V_oc) from 735mV to 818mV. However, the short circuit current (J_sc) was lower than the control samples with a decrease from 5.6mAcm^-2 to 4.3mAcm^-2. The combination of these changes resulted in a decrease in efficiency from 2.6% to 2.3%. However, when a 2.45GHz microwave heat treatment was used instead of the conventional heat treatment the efficiency rose back up to 2.5%. This increase was due to a further increase in the V_oc up to 823mV but still a lower current.