Quasi-solid-state dye sensitized solar cells with 1,3:2,4-di-O-benzylidene- D-sorbitol derivatives as low molecular weight organic gelators

Abstract

1,3:2,4-Di-O-benzylidene-D-sorbitol (DBS) and its derivatives are efficient gelators to solidify organic solvents over a wide range of polarity. In this paper we demonstrate the usefulness of certain DBS derivatives as efficient gelators to form thermoreversible gels in electrolyte solutions which are of particular interest for solar cell applications. The adjustable, high sol-gel phase transition temperature of 1,3:2,4-di-O-dimethylbenzylidene-D-sorbitol (DMDBS) with a 3-methoxypropionitrile-based electrolyte made this particular organic gelator very attractive in dye sensitized solar cells. For example, with an amphiphilic ruthenium dye and a quasi-solid-state gel electrolyte system based on 1,3:2,4-di-O-dimethylbenzylidene-D-sorbitol/3-methoxypropionitrile, a stable overall solar energy conversion efficiency of 6.1% was achieved at AM 1.5 sunlight illumination (99.8 mW cm-2).