Gel polymer electrolytes based on a novel quaternary ammonium salt for dye-sensitized solar cells

Abstract

Gel polymer electrolytes were prepared with polyacrylonitrile (PAN) and solutions of a novel quaternary ammonium salt, polysiloxane with quaternary ammonium side groups (PSQAS), in a mixture of ethylene carbonate (EC) and propylene carbonate (PC). The influences of PAN content and salt concentration on the ionic conductivity have been investigated. The ionic conductivity can be further improved with the use of the mixtures of KI and PSQAS, which can be expected as inorganic-organic salts. The gel polymer electrolytes were used in the fabrication of the dye-sensitized solar cells with a nanoporous TiO₂ working electrode, cis-di(thiocyanato)-N,N′-bis(2,2′-bipyridyl-4,4′-dicarboxylic acid) ruthenium(II) complex dye and a counter electrode based on platinized conducting glass. The cells showed open-circuit voltages (V _oc) around 0.6 V and short-circuit current densities (J _sc) larger than 7.5 mA cm⁻² under 60 mW cm⁻² irradiation. The fill factors (FF) and energy conversion efficiencies (η) of the cells were calculated to be higher than 0.56 and 4.4%, respectively.