Deep eutectic solvent based polymer electrolyte for dye-sensitized solar cells

Abstract

A polymer electrolyte using agarose as polymer matrix, NMP as solvent and deep eutectic solvent (DES) as modifier was investigated and employed in quasi-solid-state dye-sensitized solar cells (DSSC) of which the DES was composed by urea and choline chloride. The ionic conductivity of the polymer electrolytes with different urea /choline chloride ratio was studied. It was found that the maximum ionic conductivity of the polymer electrolyte was obtained at urea/choline chloride ratio of 2:1. Under the optimal urea /choline chloride ratio condition, electrochemical properties of the polymer electrolytes and the photovoltaic properties were systematically characterized by photovoltaic tests and electrochemical impedance spectra (EIS). The results showed that both ionic conductivity of electrolyte and photovoltaic performances of the DSSC was optimized with DES content of 20wt%, where the device photovoltaic parameters were as follows, Voc at 0.59 V, Jsc at 10.28 mA/cm2, FF at 0.51, and the cell efficiency at 3.18%.