Iodide-functionalized graphene electrolyte for highly efficient dye-sensitized solar cells

Abstract

1-Octyl-2,3-dimethylimidazolium iodide, ODI, was used as an electron acceptor to functionalize graphene to impart electrocatalytic activity for triiodide reduction in dye-sensitized solar cells (DSSCs). Raman and X-ray photoelectron spectroscopic measurements identified the graphene formation from graphene oxide with ODI. The resultant graphene positively charged via an intermolecular charge-transfer process with ODI showed remarkable electrocatalytic activity toward triiodide reduction. The inner work mechanism of solar cell devices was analyzed by intensity-modulated photovoltage spectroscopy, by intensity modulated photocurrent spectroscopy, and through an analysis of photovoltage transients. The results indicated that ODI-graphene electrolyte provides effective intermolecular charge transfer, thus making it feasible for use in the creation of high-performance DSSC devices.