Nanostructured Dye Sensitized Solar Cells with Different Counter Electrodes

Dye sensitized solar cells are devices that convert visible light into electricity using a dye sensitizer. They are generally low-cost, easy to make and environmentally friendly. Research in this field have mainly been focused on enhancing the performance of the devices through the optimization of its components such as the dye sensitizer and cathode. In this study, the performance of dye-sensitized solar cells fabricated with different cathode materials were tested. The experiments were carried out with one synthetic dye (N719) and two natural dyes (Pomegranate and Blueberry fruit dyes). Different cathode materials tested included thermally platinized, graphite-coated, and soot-covered Fluorine doped Tin Oxide (FTO) electrodes. The surface morphology of the different cathode materials was examined using Field Emission Scanning Microscopy and Energy-dispersive X-ray spectroscopy. The solar-to-electric energy conversion efficiencies of the devices were determined under full light illumination (100 mWcm-2, AM 1.5 Global), and the electrochemical impedance studies were carried out and compared. The efficiency of the solar cells fabricated with the graphite-based cathode electrode were determined to be higher compared to the other cathode materials used in the study. These impedance characterization results show that electron lifetimes and reaction resistances differ for the same dyes when used with different counter electrodes, providing varying photocurrent efficiencies.