Surface Modification of Polymer Counter Electrode for Low Cost Dye-sensitized Solar Cells

Poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) was already used as a counter electrode material of dye-sensitized solar cells (DSCs) in other previous researches but its low catalytic activity has been a sticking point. Here we report the catalytic activation of PEDOT:PSS counter electrode by the surface modification using nano-particles. Nano-particle addition contributes to widening catalytic interface and improving catalytic characteristics of PEDOT:PSS counter electrode. However, only a few materials are applicable although various nano-particle materials were applied for the counter electrode of DSC. Catalytic characteristics of PEDOT:PSS counter electrodes with nano-particles are analyzed by cyclic voltammetry and electrochemical impedance spectroscopy. Finally, a DSC based on catalytically enhanced polymer counter electrode achieves 0.71 V of V_OC, 12.60 mA cm^-2 of J_SC, 0.75 of FF, and 6.65% of efficiency, and it is higher than 5.60% of efficiency of a DSC based on conventional Pt counter electrode.