Controllable Synthesis of NiS/rGO Hybrid Composite: An Excellent Counter Electrode for Dye Sensitized Solar Cell

Abstract

We have synthesized an efficient NiS anchored reduced graphene oxide (rGO) nanosheet composites were by a facile hydrothermal route and served as the efficient counter electrodes (CE) for dye-sensitized solar cells (DSSCs). XRD and FESEM results suggest that the electrodes were well crystalline with formation of individual spherical like with homogeneous nanoparticles sizes in the range of 40–30 nm, which is distributed throughout the rGO sheet. The UV–Vis DRS suggest that the absorption edge of all the electrodes were in the visible light region, further it was shifted in the longer wavelength side with the increase of rGO content. The separation, transfer and recombination behavior of the photogenerated charge carriers were analyzed by PL spectra. The NiS/rGO CE produces a power conversion efficiency of 9.25%, which is higher than that (5.21%) for the DSSC with the bare CE. The enhanced efficiency of NiS/rGO hybrid composite is due to reduction of the triiodide caused by the synergistic effects between the extremely catalytic NiS nanoparticles and high electrical conductive nature of rGO sheet.