Flavonoid from Hedera helix fruits: A promising new natural sensitizer for DSSCs

Abstract

Owing to their lower cost, simplicity of manufacture, environmental friendliness, and accessibility of raw materials, natural dyes emerge as the most viable substitute for dye-sensitized solar cells (DSSCs). However, the photovoltaic performance of DSSCs based on natural dyes stays behind that of their metal-based counterparts. This can be partially overcome when appropriate chemical additives are present in the redox electrolyte employed in DSSCs based on natural dyes. To determine the ideal additives for DSSCs based on natural dye extracted from Hedera helix fruits, including flavonoid pigments, we thoroughly compare the actions of 1-butyl-3-methylimidazolium iodide, guanidinium thiocyanate, and tert-butylpyridine additives in ionic liquid-based redox electrolytes. These additives suppress undesirable charge recombination and parasitic resistance effects, achieving a more significant enhancement of open-circuit voltage (Voc) of 130 mV and fill factor (FF) of 30 % compared to their counterparts. Utilizing prepared electrolyte solutions in DSSCs also presents an outstanding increase in the efficiency of the devices, from 0.75 % to 1.17 % (∼56 % improvement), which outperforms other natural dye sources containing flavonoid pigments as well. The experimental findings provided in this study demonstrate that the development of electrolytes tailored for natural dyes can lead to greater power conversion efficiency. © 2023 Elsevier B.V.