Cornell-led team makes working chips from a record 7-volt material
Researchers have grown a semiconductor with a bandgap above 7 electron volts and built working devices from it, a study in Nature reports. That is about double silicon carbide and gallium nitride. Such materials could one day handle much higher power in grids and electric cars.
Scientists have pushed a key limit in electronics. A team led by researchers at Cornell University grew a material with a bandgap above 7.0 electron volts, or eV, and turned it into working devices. The study was published Oct. 7 in Nature.
A bandgap is how much energy it takes to get electricity flowing in a material. It sets how much voltage a chip can block and how well it handles power. Silicon, used in most chips, sits near 1.1 eV. Silicon carbide and gallium nitride, used in electric cars and fast chargers, are about 3.3 and 3.4 eV, Chip Dispatch reported. A 7 eV material is about double those.
The material is a mix of aluminum, gallium and oxygen, with silicon added. Researchers grew thin films of it on sapphire using a method called suboxide molecular-beam epitaxy, according to Nature's summary. They then built a Schottky diode, which lets current flow one way, and a field-effect transistor, a basic switch.
That is the hard part. Materials with very wide bandgaps usually act like insulators. It is tough to add atoms that let them carry current, a step called doping. This team's films conducted electricity more than 100 million times better than any earlier material with such a wide gap, Scienmag reported. The work shows a material wider than cubic boron nitride can be grown as a conductive film and used in devices.
Why it matters: Better power chips could block higher voltages, run hotter and waste less energy. That could help grid power systems, high-voltage motors and deep-ultraviolet light devices, Chip Dispatch said.
There is a long road ahead. Silicon carbide and gallium nitride each took about two decades to go from record lab results to mass production, Chip Dispatch noted.
Jacob Steele and Debaditya Bhattacharya led the work. Partners include the University of Nebraska-Lincoln, the University of Texas at Austin, the University at Buffalo, Clark Atlanta University and Lund University.
What we know: The team made a working diode and transistor from a 7 eV material.
What we don't: Whether it can be made on full wafers at scale.
Where outlets agree Nature's summary and Scienmag both report silicon-doped films with bandgaps above 7.0 eV that were built into a Schottky diode and a transistor.
Where they differ Researchers show working devices, but Chip Dispatch notes it is unclear whether the material can be made reliably at wafer scale.