MORE POWER TO YOUUTAH AND MINNESOTA ENGINEERS DISCOVER HIGHLY CONDUCTIVE MATERIALS FOR MORE EFFICIENT ELECTRONICS.

Engineers from the University of Utah and the University of Minnesota have discovered that interfacing two particular oxide-based materialsmakes them highly conductive, a boon for future electronics that could result in much more power-efficient laptops, electric cars and homeappliances that also don’t need cumbersome power supplies.

Their findings were published this month in the scientific journal, APL Materials, from the American Institute of Physics.

The team led by University of Utah electrical and computer engineering assistant professorBerardi Sensale-Rodriguez and University of Minnesota chemical engineering and materialsscience assistant professor Bharat Jalan revealed that when two oxide compounds — strontiumtitanate (STO) and neodymium titanate (NTO) — interact with each other, the bonds between theatoms are arranged in a way that produces many free electrons, the particles that can carryelectrical 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 whatis possible in semiconductors. “It is also about five times more conductive than silicon [thematerial most used in electronics],” Sensale-Rodriguez says.

This innovation could greatly improve power transistors — devices in electronics that regulatethe electrical current —by making power supplies much more efficient for items ranging fromtelevisions and refrigerators to handheld devices, Sensale-Rodriguez says. Today, electronics manufacturers use a material called gallium nitridefor transistors in power supplies and other electronics that carry large electrical currents. But that material has been explored and optimized formany years and likely cannot be made more efficient. In this discovery made by the Utah and Minnesota team, the interface between STO andNTO can be at the very least as conductive as gallium nitride and likely will be much more in the future.

“When I look at the future, I see that we can perhaps improve conductivity by an order of magnitude through optimizing of the materialsgrowth,” Jalan says. “We are bringing the possibility of high power, low energy oxide electronics closer to reality.”

Power transistors that use this combination of materials could lead to smaller devices and appliances because their power supplies would bemore energy efficient. Laptop computers, for example, could ditch the bulky external power supplies — the big black boxes attached to thepower cords — in favor of smaller supplies that are instead built inside the computer. Large appliances that consume a lot of electricity such asair conditioners could be more power efficient. And because there is less power wasted (wasted electricity usually dissipates into heat), thesedevices will not run as hot as before, says Sensale-Rodriguez. He also believes that if more electronics use these materials for transistors,collectively it could save significant amounts of electricity for the country.

“It’s fundamentally a different road toward power electronics, and the results are very exciting” he says. “But we still need to do more research.”

Co-authors on the paper also include: University of Utah electrical and computer engineering professor Ajay Nahata; U graduate students SaraArezoomandan, Hugo Condori Quispe, Ashish Chanana; and Minnesota graduate student Peng Xu. The work at University of Minnesota isfunded by the Air Force Young Investigator Research Program, and the work in Utah is primarily supported by the National Science Foundation’sMaterials Research Science and Engineering Center at the University of Utah.