Modification of juglon dye as a sensitiser in dye-sensitised solar cells

Natural juglon dye was obtained from the outer shell of walnut (Juglans Regia L.) fruit by hot extraction method followed by doping using aluminium, copper and iron metals. These metal-free and metal-doped juglon dyes were used as sensitisers in the production of titanium dioxide (TiO₂)-based dye-sensitised solar cells. The absorption results show that the metal-doped dyes have a wider absorption spectra than metal-free dyes and TiO₂ alone. The best performance was achieved by the copper-doped juglon-based sensitiser, resulting in an efficiency of 1.63%. Moreover, the incident photon-to-current efficiency curve indicates that both copper- and iron-doped juglons have promise as dye-sensitised solar cells technologies. These findings confirm that metal-free and metal-doped dye-sensitised solar cells have scientific and industrial potential owing to their simple and inexpensive production method.