Iridium dimer complex for dye sensitized solar cells using electrolyte combinations with different ionic liquids

In this paper, we report the synthesis and characterization of a new cyclometallated iridium complex, [tetrakis(2,2′-bipyridine-4,4′-dicarboxylic acid)(μ-dichloro)diiridium(III)] chloride complex, [(dcbpy)2Ir(μ-Cl)]2Cl4. Four different ionic liquids are also synthesized and characterized for electrolyte combinations. Photovoltaic performance of dye sensitized solar cells have been studied by using four different ionic liquids. The dye sensitized nanocrystalline TiO2 solar cell (DSSC) based on the iridium complex using triethyleneglycol-bis(3-methylimidazolium)diiodide [K36-TFSI] as ionic liquid in electrolyte showed the best photovoltaic performance with a maximum short-circuit photocurrent density (Jsc) of 4.45 mA cm−2, an open circuit photovoltage (Voc) of 550 mV, and a fill factor (FF) of 0.60, corresponding to an overall conversion efficiency of 1.47% under AM 1.5 sun light.