Dye‐sensitized solar cells based on nickel‐doped tungsten diselenide counter electrodes

Abstract

Dye-sensitized solar cells (DSSCs) are gaining considerable interest as substitutes to solar cells based on semiconductor thin-films owing to their costeffective and effortless fabrication methods. Efforts are being made to replace counter electrodes (CE) in DSSCs, which are conventionally based on noble metal platinum (Pt). Among the new materials as CE, two-dimensional (2D) transition metal dichalcogenide is one of the most explored to develop Pt-free DSSCs. We report here the preparation of TiO 2 -based DSSCs using beetroot (Beta vulgaris) extracts as sensitizers with carbon-, pristine-, and Ni (4%)-doped WSe 2 as the CEs. The Ni (4%) WSe 2 CE exhibited a high-power conversion efficiency (PCE) of 5.66% under the illumination of 100 mW cm À2 .The electrical characteristics, including I-V, C-V, and electrochemical impedance spectroscopy, corroborate the better efficiency of Ni (4%) WSe 2 CE. The cost-effectiveness and efficiencies obtained for Pure and Ni (4%) WSe 2 make them a worthy candidate as CE for DSSCs.