Optimal‐Temperature‐Based Highly Efficient NiS Counter Electrode for Quantum‐Dot‐Sensitized Solar Cells

Abstract

AbstractMetal sulfide electrodes were compared to a conventional platinum (Pt) counter electrode (CE) in quantum‐dot‐sensitized solar cells (QDSSCs), in which they were used to improve the short circuit current, fill factor, and conversion efficiency (η). We deposited optimal‐temperature‐based nickel sulfide (NiS) thin films on a fluorine‐doped tin oxide (FTO) substrate by a facile chemical bath deposition method and successfully employed them as a highly efficient CE for QDSSCs. The obtained NiS thin‐film nanoparticles exhibit high electrocatalytic performance and fast mass transfer rates toward the polysulfide electrolyte. Under the illumination of one sun (100 mW cm–2), the QDSSC with a NiS CE produces a higher η of 3.30 %, which is much higher than that of a Pt CE (1.89 %). Cyclic voltammetry, electrochemical impedance spectroscopy, and Tafel polarization measurements were performed to investigate the electrocatalytic activity of the NiS CE toward polysulfide electrolyte.