Abstract
A novel family of room temperature ionic liquids, N,N-diethyl-N,N-dipropyl-N-hexyl-N-methylguanidinium iodide (SGI) and N,N,N,N-tetramethyl-N,N-dipentylguanidinium tricyanomethanide (SGTM) were designed and synthesized. Due to the strong charge delocalization on the tricyanomethanide anion and, thus, weaker ion-pairing, SGTM has a lower viscosity than SGI salt that has iodide as an anion. SGI was successfully used as an iodide resource for dye-sensitized nanocrystalline solar cells. The device with a solvent-free, SGI-based electrolyte achieved a 5.9% power conversion efficiency under an air mass 1.5 incident light of 9.47 mW/cm.