Scientists seek to improve efficiency of dye-sensitized solar cells with halogenes

A group of researchers from the University of British Columbia and the University of North Carolina at Chapel Hill is seeking to improve the performance of dye-sensitized solar cells by using halogens, a class of elements that include fluoride, bromine, chlorine and iodine.

In a study published on the scientific magazine Nature, the researchers claim that the use of halogens may boost the conversion efficiency of this kind of cell by a further 25%. According to them, the presence of these elements in a dye-sensitized cell is capable of accelerating the electron transfer between the electrolyte and the semiconductor.

Four different dyes containing fluoride, bromine, chlorine or iodine were used in the experiment, while the whole process was observed through a X-ray absorption spectroscopic technique.

The researchers also showed that larger halogens perform better at accelerating the aforementioned electron transfer, and that dyes containing iodine were regenerated almost three times faster by the electrolyte.

“Halogens haven't been the focus of much solar cell research. They form very weak, transient bonds that exist for less than 10 microseconds, and they typically make up just a tiny portion of all the atoms in a solar cell. We're thrilled to prove that these bonds can make such a significant difference in solar energy conversion,” said one of the research co-authors Curtis Berlinguette.