Highly Efficient Nitrogen-Doped Reduced Graphene Oxide-Sr0.7sm0.3fe0.4co0.6o2.65 Nanocomposites Utilized As a Counter Electrode in Dye-Sensitized Solar Cells

Dye-sensitized solar cells (DSSCs) are known for their aesthetic properties, not limited to colour tuneability and transparency, but are also promising renewable energy technology that can efficiently harvest sunlight to generate electricity without releasing toxic gases. DSSCs are one of the potential candidates for fabricating colourful and see-through solar cells for energy-harvesting aesthetic windows. However, a trade-off between transparency and power conversion efficiency (PCE) has to be tackled amicably to realize solar cells with good PCE and transparency. Judicious selection of dyes to bypass light absorption in the high eye-sensitivity region (500 – 600 nm) is one of the plausible solutions. Most importantly, developing novel counter electrode materials using facile preparation techniques, low-cost materials, and environmentally friendly conditions helps overcome the limitations of commonly used but expensive and corroding metals, thereby improving the PCE of DSSCs. Herein, we report the synthesis of a novel hybrid nitrogen-doped reduced graphene oxide-Sr0.7Sm0.3Fe0.4Co0.6O2.65 (N-RGO-SSFC) nanocomposite using the thermal treatment method. The N-RGO-SSFC nanocomposites were characterized using microscopic and spectroscopic techniques and applied as counter electrodes in DSSCs. Scanning electron microscopy images revealed the presence of N-RGO sheets decorated by SSFC nanoparticles. The introduction of SSFC nanoparticles onto N-RGO sheets led to the formation of nanocomposites with a tetragonal structure, a surface area of 178.0 m2 g-1, an electrical conductivity of 13.02 S cm-1, and a charge transfer resistance of 10.6 Ω. The N-RGO-SSFC nanocomposite counter electrodes resulted in DSSCs with an enhanced PCE of 6.64% due to the formation of excellent electron transfer pathways. This outperformed DSSCs based on the Pt reference electrode with a PCE of 5.52%. Hence, N-RGO-SSFC nanocomposites can be applied as a potential counter-electrode material in DSSCs.