Highly catalytic reduced graphene oxide decorated Cu2S counter electrode boosting quantum dot–sensitized solar cell performance

Abstract This paper shows the outcomes of making and planning quantum dot solar cells with cathode electrodes made from a nanocomposite of rGO and Cu 2 S. The hydrothermal method is used to make this stuff into a powder, which is then mixed with polyethylene glycol and polyvinylpyrrolidone to make a paste coating that is then printed onto an FTO substrate that is conductive. Cu 2 S, rGO, and rGO@Cu 2 S nanocomposite electrodes, with the initial mass of graphene oxide varying at 8 mg, 12 mg, and 16 mg. The composition and structure of the films were determined using EDX mapping, XRD, Raman spectroscopy, and FTIR spectra, confirming that they were successfully fabricated. In addition, the results showed that the surface of the film is very porous, making it suitable for electrode fabrication. The results of measuring the PCE show that the efficiency has been effectively improved. The efficiency of the rGO counter electrodes is increased as compared to the Cu 2 S counter electrodes. The device has the highest efficiency of 5.665%, V OC = 0.48V, J SC = 22.776 mA cm −2 , and FF = 0.518 for the 12 mg-rGO@Cu 2 S counter electrode. This result shows that the support of the graphene network helps the Cu 2 S nanoparticles be distributed more evenly when Cu 2 S material is directly coated on the FTO. Besides, the graphene network also helps to make the electrons transition to the polysulfide more flexible, which is proven through cyclic voltammetry and electrochemical impedance spectroscopy results.