Pyranoflavylium Derivatives Extracted from Wine Grape as Photosensitizers in Solar Cells

Abstract

Pyranoflavylium derivatives, namely cyanidin-3-glucoside, malvidin 3-O-glucoside, malvidin 3-O-coumaroylglucoside, cyanidin 3-glucoside-pyruvic acid adduct and malvidin 3-glucosidepyruvic acid adduct, extracted from red grapes were used as sensitizers in dye-sensitized solar cells (DSSCs). With these natural dyes, cell's efficiencies ranged up to 0.08%. The cyanidin based dyes were more efficient as sensitizers than the malvidin molecules and the presence of the pyruvic acid adduct decreased efficiency. Furthermore, the use of drops of Port wine in the production of DSSCs resulted in an efficiency of 0.025%. Although the obtained efficiencies still need improvements for an industrial application, it is given further evidence that wine dyes can harvest and convert sunlight into electricity through a process that mimics natural photosynthesis.