Ionic liquid gel electrolytes for quasi-solid-state dye-sensitized solar cells

Abstract

A novel ionic liquid gel electrolyte was successfully prepared and used in dye-sensitized solar cells. The ionic liquid gel was formed via the self-assembly of a low molecular weight gelator in ionic liquid. The properties of the ionic liquid gel were measured by POM, gel-to-sol phase transition temperature, cyclic voltammogram. All the ionic liquid gels appeared as soft solid at room temperature and become liquid at a high temperature. The ionic liquid gel showed a room temperature conductivity of 2.9mScm−1. The DSSC with ionic liquid gel electrolyte not only showed a photoconversion efficiency of 3.63%, but also exhibited a better long-term stability than the DSSC with the liquid electrolyte at the same conditions. Since the ionic liquid gel electrolyte is solvent-free, highly conductive and electrochemically compatible, it is possible to use this type electrolyte for development of practical DSSCs.