Bifacial DSSC fabricated using low-temperature processed 3D flower like MoS2 - high conducting carbon composite counter electrodes

Abstract

3D flower-like MoS2 nanostructures are synthesised using hydrothermal method at different S:Mo ratios. The grown MoS2 nanostructures exhibit 2H-MoS2 phase with P63/mmc space group, which can be inferred from XRD results. The calculated lattice parameters and inter planar spacing values are in good agreement with the literature. FESEM images show flower like morphology of the grown nanostructures. HRTEM micrographs are used to examine microstructural properties and to determine the interplanar spacing (d). The peaks observed in Raman spectra at ∼380 and ∼404 cm−1 are designated to E2 g1 mode and A1g mode respectively. Elemental analysis is carried out using XPS analysis. Counter electrodes (CE) for dye sensitised solar cells (DSSC) are fabricated using MoS2-high conductive carbon paste (HCP) composite. Simple spin coating method is used to deposit CE with a low annealing temperature of 80 °C which is suitable for even plastic substrates. Using Nyquist and Bode plot, series resistance (9.02 Ω cm2), charge transfer resistance (17.48 Ω cm2) and electron lifetime (63 ms) is calculated. The fabricated DSSC shows a power conversion efficiency of 4.50 % when illuminated from the front side whereas 2.40 % in the case of rear illumination.