Nickel selenide/reduced graphene oxide nanocomposite as counter electrode for high efficient dye-sensitized solar cells.

Nickel selenide/reduced graphene oxide (Ni0.85 Se/rGO) nanosheet composite is synthesized by a facile hydrothermal process and used as counter electrode (CE) for dye-sensitized solar cells (DSSC). The Ni0.85 Se/rGO film spin-coated on FTO show prominent electrocatalytic activity toward I3 - /I- . The electrocatalytic ability of Ni0.85 Se/rGO film is verified by photocurrent-voltage curves, cyclic voltammetry, electrochemical impedance spectroscopy and Tafel polarization curves. On account of its decent electrical conductivity and superior electrocatalytic activity, the DSSC using optimal Ni0.85 Se/rGO CE achieves a power conversion efficiency (PCE) of 9.75%, while the DSSC based on sputtered Pt CE only obtains a PCE of 8.15%.