doi:10.1038/nindia.2013.115 Published online 28 August 2013
Researchers have produced a new dye that when deposited on a titanium dioxide thin film converts solar energy very efficiently into electrical energy . Such dye-modified films are very promising for harnessing solar energy, providing an ecofriendly way to generate electricity.
In recent years, dye-sensitized solar cells (DSSCs) have emerged as a promising alternative to silicon-based solar cells because of their superior ability in converting solar energy to electrical energy. Ruthenium-based black dye is generally used for making DSSCs. However, its solar-to-electrical energy conversion efficiency is not suitable for fabricating solar cells for large-scale applications.
The researchers overcame this limitation by synthesizing a new dye from ruthenium-based organic compounds. By hydrolyzing these compounds with triethylamine, they obtained a dark green material, which they filtered, washed with water and diethyl ether, and dried to produce a dark green powder dye.
The green dye showed broad light absorption at visible and near-infrared wavelengths, which that was significantly higher than that of commercial black dye.
To probe the efficiency of the dark green dye in converting solar energy to electrical energy, they smeared it on a transparent, titanium dioxide thin film. The dye exhibited an excellent light-absorption efficiency and a high capacity for generating electrical energy from solar energy. During energy conversion, electrons were transferred from the dye to the thin film.