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

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 degrees 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).