▎ 摘 要
In this work carbon based nanomaterials in ionic liquids have been studied as potential electrolytes for dye sensitised solar cells (DSSCs). Graphene, single wall carbon nanotubes (SWCNTs) and a mixture of graphene and SWCNTs were incorporated into 1-methyl-3-propylimidazolium iodide (PMII) ionic liquid. The resulting quasi-solid state electrolytes were sandwiched between TiO2 working electrodes and platinum counter electrodes and subsequent DSSCs were fabricated. Graphene based quasi-solid state electrolytes displayed an increase of light conversion efficiencies in the completed DSSC from 0.16% (for pure PMII) to 2.10%. For SWCNTs, the observed light conversion efficiency increased from 0.16% to 1.43% and for the mixture of graphene and SWCNTs the light conversion efficiency improved from 0.16% to 2.50%. This significant increase occurred because the carbon materials serve simultaneously both as charge transporter in the ionic liquids and as catalyst for the electrochemical reduction of I-3(-). It is also expected that there is an ionic liquid mediated self-organisation of graphene and SWNT nanomaterials into structured networks, which provide an efficient electron transfer. Thermogravimetric analysis (TGA) studies showed that these electrolytes are stable up to 300 degrees C.