Suppressing charge recombination in disordered polymers blend medium

Abstract

Charge recombination is one of the critical factors that influences the performance of thin film polymer solar cells (TFPSCs). In this investigation, metal, plasmonic nano-particles are employed to suppress charge recombination and energy loss in TFPSC. Trimetallic nano-composite (NC) was successfully synthesized and composed of copper, nickel, and silver (Cu/Ni/Ag) using wet chemistry. The NC was incorporated into polymer-based solar absorber layers at different concentrations. The absorber layer is a fullerene-based bulk-heterojunction design using poly-3-hexylthiophene (P3HT) donor polymer. The results show that the power conversion efficiency of the device doped with NC has improved by 85% compared to the undoped one. The incorporation of tri-metallic NC into the polymer blend solar absorber resulted in enhanced optical absorption and improved collection of photo-current as reflected by the recorded high short circuit current density (J ) and fill factor. The enhancement of the performance is due to the occurrence of local surface plasmon resonances in the polymer medium. The experiment indicated that there is some increment in an open circuit voltage, which is attributed to the low energy losses as a result of improved exciton dissociation, charge carrier transport, and collection.