Dye-sensitized solar cell (DSSC) was fabricated by a suitable counter electrode (CE) based on graphenenanosheets in order to facilitate electrochemical reduction of triiodide in organic medium. Grapheneoxide (GO) nanosheets were deposited at fluorine doped tin oxide (FTO) glass substrate by elec-trophoretic deposition (EPD) technique as an easy short-time method. Then GO nanosheets wereconverted to electrochemically reduced graphene oxide (ERGO) nanosheets by chronoamperometerytechnique. Graphene nanosheet-based electrode was modified by silver nanoparticles and was char-acterized by field emission scanning electron microscopy (FE-SEM), energy dispersive spectroscopy(EDS), X-ray elemental mapping (MAP) and atomic force microscopy (AFM) studies. Also, the electro-chemical behaviors of as-prepared electrodes were investigated by cyclic voltammetry method whereelectrodes fabricated by graphene-silver nanohybride (Ag/ERGO/FTO) presented the highest currentdensity and the lowest peak-to-peak separation in comparison to bare FTO, GO/FTO and ERGO/FTOelectrodes in iodine electrolyte medium. Moreover, electrochemical impedance spectroscopy (EIS) wasapplied to investigate the electrocatalytic capability of the modified electrode both in I3−/I−elec-trolyte and as a symmetrical dummy cell which represented relatively lower charge transfer resistance. Finally, the fabricated DSSC containing Ag/ERGO/FTO CE represented suitable photovoltaic characteristicparameters (Voc= 0.8 V, jsc= 29.04 mA cm−2and _ = 4.24%) under simulated light of AM1.5 G (1000 W m−2)compared to Pt-based DSSC (Voc= 0.66 V, jsc= 19.54 mA cm−2and _ = 6.08%). Furthermore, the high con-ductivity of the cells was evaluated by EIS during the applying different biases.
