Effects of hydrazine hydrate treatment on the performance of reduced graphene oxide film as counter electrode in dye-sensitized solar cells

The reduced graphene oxide (RGO) counter electrodes were prepared by drop casting method and followed by heat treatment. The as-prepared RGO counter electrodes were used as substitution for Pt counter electrode in dye-sensitized solar cells (DSSCs). The effects of hydrazine hydrate in graphene oxide (GO) suspension on the performance of RGO counter electrodes were investigated. The cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurements revealed that a moderate amount of hydrazine hydrate can enhance the catalytic activity of the RGO film toward the reduction of I3− and decrease the sheet resistance of the film. The efficiency (η) of DSSC based on the RGO counter electrodes with optimum addition of hydrazine hydrate increased from 1.826% to 2.622% under a simulated solar illumination of 100 mW cm−2 (AM 1.5).