The team led by University of Utah electrical and computer engineering assistant professor Berardi Sensale-Rodriguez and University of Minnesota chemical engineering and materials science assistant professor Bharat Jalan revealed that when two oxide compounds — strontium titanate (STO) and neodymium titanate (NTO) — interact with each other, the bonds between the atoms are arranged in a way that produces many free electrons, the particles that can carry electrical current. STO and NTO are by themselves known as insulators — materials like glass — that are not conductive at all.
But when they interface, the amount of electrons produced is a hundred times larger than what is possible in semiconductors. “It is also about five times more conductive than silicon [the material most used in electronics],” Sensale-Rodriguez says.
This innovation could greatly improve power transistors — devices in electronics that regulate the electrical current —by making power supplies much more efficient for items ranging from televisions and refrigerators to handheld devices, Sensale-Rodriguez says. Today, electronics manufacturers use a material called gallium nitride for transistors in power supplies and other electronics that carry large electrical currents. But that material has been explored and optimized for many years and likely cannot be made more efficient. In this discovery made by the Utah and Minnesota team, the interface between STO and NTO can be at the very least as conductive as gallium nitride and likely will be much more in the future.