When most people think of semiconductors they think of silicon, but the family of semiconducting materials is much larger than just one compound. Gallium Nitride (GaN) is another semiconductor that has been in use since the 1990s, thanks to its high efficiency and high voltage operation. At such high voltages though, the material will put out a great deal of heat, which can greatly shorten its lifespan and limit its application. Researchers at the University of California, Riverside have given the material new life with a new cooling system that can drop temperatures by as much as 20 ºC.
This new material is based on graphene, a form of carbon that makes a sheet just one-atom thick. It is not single-layer graphene that is used though, but multiple layers to the point of the reaching graphite. In some ways graphite can be thought of as multiple layers of graphene, but it is not quite that simple as the graphene in pencil lead is not so well ordered.
Both single and multi-layered graphene conduct heat very well, which is what the researchers were hoping for. In fact the researchers were able to drop the temperature in some hot spots by 20 ºC and computer simulations suggest ways to make it even more efficient.