A research group from Northwestern University has unveiled a new type of dye-sensitized (organic) solar cell that is a technological leap forward and that will make Michael Grätzel proud of his invention. Their new solar cell is not more efficient, but lasts for longer in real life conditions.
Current dye-sensitized solar cells use a liquid electrolyte. That’s a good option if you want a better efficiency (up to 12 percent), but bad because the liquid often leaks and corrodes the solar cell.
The Northwestern team, led by Robert P.H. Chang and Mercouri Kanatzidis made a solid electrolyte to replace the liquid one and make the overall solar cell more stable.
“The Grätzel cell is like having the concept for the light bulb but not having the tungsten wire or carbon material,” said Kanatzidis, of the need to replace the troublesome liquid. “We created a robust novel material that makes the Grätzel cell concept work better. Our material is solid, not liquid, so it should not leak or corrode.”
They devised a thin film compound of cesium tin and iodine (CsSnI3) and even hope to exceed the performance of the original Grätzel cell by using nanotechnology. They used both n-type and p-type semiconductors and a single-layered dye molecule linking the two. Each titanium dioxide spherical nanoparticle is the n-type semiconductor, while the CsSnI3 material is the p-type.
By joining millions of such nanoparticles, the researchers obtained a huge surface area that they covered with light-absorbing dye, thus increasing the efficiency.
The two scientists now hope that their technology will be recognized and applied as mainstream, fact which will save unnumbered quantities of toxic materials used to make silicon solar cells.