High efficiency dye-sensitized solar cells with tetra alkyl ammonium cation-based ionic liquid functionalized graphene oxide as a novel additive in nanocomposite electrolyte

For the first time, we report on the preparation of highly effective electrolyte additive by combining graphene oxide (GO) covalently functionalized with ammonium-based ionic liquid in dye-sensitized solar cell (DSSC). GO was modified in two-step, first, with 1-6, hexamethylenediamine then, the products were reacting with alkyl-halide. The effects of GO-hexamethylene tributyl-ammonium iodide and GO-hexamethylene trimethyl-ammonium iodide as additives on the photovoltaic performance of DSSCs were studied to find the ideal characteristics for minimize the aggregation in ionic liquids based electrolytes. The investigation showed the addition of IL-functionalized GO forms a molecular bridge for electrons transfer in the ionic liquid based electrolyte that has a significant increase in photovoltaic density (Jsc) from 7.141 to 16.847 mA cm(-2) more than twice. Under an optimized additive/ electrolyte ratio of 4 wt%, the conversion efficiency of DSSCs was remarkably enhanced to 8.33% from initial 3.96% that of referenced ionic liquids-based device. Furthermore, based on these nanocomposite electrolytes, the resulting DSSCs exhibited better electron diffusion coefficient of I- and I-3(-) and ionic conductivity which improves Jsc. It is anticipated that this work may provide an effectual way to develop nanocomposite consisting of graphene derivatives as a great potential for practical application. (C) 2017 Elsevier Ltd. All rights reserved.