Physicists at Aalto University in Finland, with colleagues in Texas and Poland, have shown that beryllium doping can prove beneficial in gallium nitride (GaN) power electronics. The team made a breakthrough in revising methods largely discarded 15 years ago. A paper on their work is published in the journal Physical Review Letters.
There is growing demand for semiconducting gallium nitride in the power electronics industry. To make electronic devices that can process the amounts of power required in, say, electric cars, we need structures based on large-area semi-insulating semiconductors with properties that allow minimizing power loss and can dissipate heat efficiently. To achieve this, adding beryllium into gallium nitride—or doping it—shows great promise.—Professor Filip Tuomisto from Aalto University
Experiments with beryllium doping were conducted in the late 1990s in the hope that beryllium would prove more efficient as a doping agent than the prevailing magnesium used in LED lights. The work proved unsuccessful, however, and research on beryllium was largely discarded.
The current study shows that depending on whether the material is heated or cooled, beryllium atoms will switch positions, changing their nature of either donating or accepting electrons.
Our results provide valuable knowledge for experimental scientists about the fundamentals of how beryllium changes its behaviour during the manufacturing process. During it—while being subjected to high temperatures—the doped compound functions very differently than the end result.—Filip Tuomisto
If the beryllium-doped gallium nitride structures and their electronic properties can be fully controlled, power electronics could move to a whole new realm of energy efficiency.
The magnitude of the change in energy efficiency could as be similar as when we moved to LED lights from traditional incandescent light bulbs. It could be possible to cut down the global power consumption by up to ten per cent by cutting the energy losses in power distribution systems.—Filip Tuomisto
Filip Tuomisto, Vera Prozheeva, Ilja Makkonen, Thomas H. Myers, Michal Bockowski, and Henryk Teisseyre (2017) “Amphoteric Be in GaN: Experimental Evidence for Switching between Substitutional and Interstitial Lattice Sites” Phys. Rev. Lett. 119, 196404 doi: 10.1103/PhysRevLett.119.196404