Enhanced performance in dye-sensitized solar cells via carbon nanofibers–platinum composite counter electrodes

Abstract

A composite counter electrode (CE) made of electrospun carbon nanofibers (ECNs) and platinum (Pt) nanoparticles has been demonstrated for the first time to improve the performance of dye-sensitized solar cells (DSCs). The new ECN–Pt composite CE exhibited a more efficient electro-catalytic performance with lower charge transfer resistance (R_ct), larger surface area, and faster reaction rate than those of conventional Pt. It reduced the overall series resistance (R_se), decreased dark saturation current density (J₀) and increased shunt resistance (R_sh) of the DSCs, thereby leading to a higher fill factor (FF) and larger open circuit voltage (V_oc). The reduced electron transport resistance (R_s) and faster charge transfer rate in the CE led to a smaller overall cell series resistance (R_se) in the ECN–Pt composite based DSCs. The DSCs based on an ECN–Pt CE achieved a η of ∼8%, which was improved over those of pure Pt or ECN based cells.