Modified Hagfeldt Donor for Organic Dyes That Are Compatible with Copper Electrolytes in Efficient Dye-Sensitized Solar Cells

A series of anthracene-based LC dyes featuring modified bulky Hagfeldt donors have been designed and synthesized for copper electrolyte-based dye-sensitized solar cells (DSSCs). In the LC dyes, two more alkoxy chains are introduced into phenyl substituents in the well-known Hagfeldt donor framework to further attenuate charge recombination in DSSCs, which is demonstrated by photovoltaic and electrochemical studies. LC4-based DSSCs fabricated with the CuI/II(dmp)2(TFSI)1/2 (dmp = 2,9-dimethyl-1,10-phenanthroline, TFSI = bis(trifluoromethylsulfonyl)imide) electrolyte exhibit a high open circuit voltage (VOC = 1.095 V), short-circuit photocurrent (JSC = 10.500 mA cm-2), fill factor (FF = 0.757), and power conversion efficiency (PCE = 8.70%), which are better than those of its counterpart TY6 with a PCE of 5.66% (JSC = 8.637 mA cm-2, VOC = 1.048 V, FF = 0.626), demonstrating that the modified bulky donor is a promising building block for organic sensitizers.

Automated summary

A series of anthracene-based LC dyes with modified bulky Hagfeldt donors were synthesized for copper electrolyte-based dye-sensitized solar cells (DSSCs). The introduction of additional alkoxy chains in the phenyl substituents of the LC dyes effectively reduces charge recombination, as demonstrated by photovoltaic and electrochemical studies, leading to improved performance compared to traditional dyes.