Researchers at the University of Utah and the University of Minnesota have discovered that when two oxide compounds—strontium titanate (STO) and neodymium titanate (NTO)—are joined together, they make an extraordinary conductive material that could vastly improve power transistors. The researchers have shown that these two materials—which on their own operate as insulators—are up to five times more conductive than silicon.
In research described in the journal APL Materials, scientists found that the bonds between the atoms from the oxide compounds arrange themselves in a way that generates 100 times more free electrons than conventional semiconductors, which means the new material can transport more electrical current.
The main application for a material with this level of conductivity would be in power transistors that regulate electrical current in electronic devices such as televisions and cellphones.
Currently, gallium nitride serves as the material used for transistors in power supplies. While gallium nitride is highly conductive as well, many believe that years of optimization have brought the material to its limits. This new STO/NTO material still has room for further optimization and improvement and eventually may serve as an attractive replacement for gallium nitride.
“When I look at the future, I see that we can perhaps improve conductivity by an order of magnitude through optimizing of the material’s growth,” said Bharat Jalan of the University of Minnesota in a press release. “We are bringing the possibility of high power, low energy oxide electronics closer to reality.”
These materials could be used in power transistors to enable much smaller devices, because the power supplies would be far more efficient. Take the external power supplies that come with our laptops and the big black box halfway down the electrical cord. By building far smaller power supplies inside the laptop, the need for these large external power supplies could be eliminated.
Researchers around the world have focused a great deal on using nanomaterials to address heat management issues in electronics. This latest research offers a new approach to reducing these temperatures in electronic gadgets. By making more efficient power transistors, less power is wasted, and because wasted electricity is given off as heat, these devices will not run as hot as they have in the past.
Berardi Sensale-Rodriguez of the University of Utah believes that if this material is adopted it could lead to a significant reduction in electricity use.
However, Sensale-Rodriguez does temper his enthusiasm somewhat, adding: “It’s fundamentally a different road toward power electronics, and the results are very exciting. But we still need to do more research.”
Dexter Johnson is a contributing editor at IEEE Spectrum, with a focus on nanotechnology.