A PDDA functionalized nitrogen and sulphur doped graphene composite as the counter electrode for dye-sensitized solar cells

Poly-diallyldimethylammonium chloride (PDDA) functionalized nitrogen and sulphur doped graphene (SN-Gp) was synthesized as a Pt-free counter electrode (CE) for developing highly efficient and low cost dye sensitized solar cells (DSSCs). The structural and chemical composition of the as-prepared PDDA/SN-Gp hybrid composite was analyzed by X-ray diffraction (XRD) analysis, high resolution electron transmission microscopy (HR-TEM), Raman spectroscopy and cyclic voltammetry (CV). The PDDA/SN-Gp hybrid counter electrode displayed an adsorption controlled process towards the (I−/I3−) redox couple and the value was calculated to be 2.253 × 10−9 mol s−1 by varying the scan rate. The PDDA/SN-Gp hybrid counter shows a very low charge transfer resistance of 1.70 Ω and maximum fill factor of 61.53%.