Carbonaceous-MoS2 nanoflower-based counter electrodes for bifacial dye-sensitized solar cells

Abstract

MoS2-based transition metal dichalcogenide nanoflowers are synthesized using the hydrothermal method and their potential as a counter electrode in dye-sensitized solar cells (DSSCs) is examined. Structural analysis of synthesized MoS2 is analysed using x-ray diffraction spectra and Raman spectroscopy. The morphology and microstructural properties are investigated using field-emission scanning electron microscopy and high-resolution transmission electron microscopy, respectively. DSSCs are fabricated using different counter electrodes (MoS2, MoS2-carbon black and MoS2-high conductive carbon paste (HCP)), which are deposited using a simple spin-coating method and annealed at a temperature of 80 °C. The electrochemical properties of the fabricated counter electrodes are studied using electrochemical impedance spectroscopy. Among the different counter electrodes, MoS2–HCP shows better electrochemical performance. The high electrocatalytic and conducting nature of the MoS2–HCP-based counter electrode produces 5% power conversion efficiency, which is comparable to expensive Pt-based counter electrodes (5.4%). To demonstrate the bifacial concept of DSSC, 2.2% power conversion efficiency is attained with rear-side illumination under one sun (100 mW cm−2, AM 1.5 G).