Gelation of a liquid electrolyte with aniline for use in a quasi-solid-state dye-sensitized solar cell

A new kind of gel electrolyte containing only organic solvents and an iodide salt??namely 3-methoxypropionitrile (MPN), aniline and AlI₃??has been prepared. Gel formation results from the Lewis acid-base interaction between the Lewis acid ionic conductor AlI3 and the Lewis base organic solvent aniline and no additional gelling agent is required. The AlI₃-aniline complex acts both as an ionic conductor and as a gelling agent. The differences between the peaks characteristic of the ??NH₂ group and aromatic ring in the FTIR spectra of free aniline and the AlI₃-aniline hybrid confirm the formation of the AlI₃-aniline complex. The photovoltaic performance and long-term stability of dye-sensitized solar cells can be greatly enhanced by the addition of aniline to the AlI₃-MPN liquid electrolyte.