Synergetic effect of a polymer and metalloid composite on the electrocatalytic improvement of dye-sensitized solar cells

Abstract

A conductive polymer, poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS), is often used as a counter electrode in low-cost dye-sensitized solar cells (DSSCs). However, its low electrocatalytic activity causes a low fill factor, leading to a decrease in photoconversion efficiency. Here, a PEDOT:PSS solution and silicon nanoparticles (Si NPs) were mixed uniformly to form a PEDOT:PSS/Si NP electrocatalyst. In order to attain higher electrocatalytic activity, both the particle size and amount of Si NPs were controlled, and their effect on the electrocatalytic activity was investigated. Their electrocatalytic characteristics were analyzed by cyclic voltammetry and electrochemical impedance spectroscopy. Finally, a DSSC based on the PEDOT:PSS/Si NP electrocatalyst containing 120 mg of Si NPs achieved an efficiency of 6.645% under standard solar irradiation of 100 mW cm⁻². The performance was comparable to that of a conventional DSSC based on a Pt electrocatalyst.