Aalto University physicists have discovered a microscopic mechanism that will allow gallium nitride semiconductors to be used in electronic devices.
The breakthrough lies in using beryllium atoms in gallium nitride which leads to the distribution of large amounts of electric power in everyday devices.
Gallium nitride is a compound widely used in semiconductors in consumer electronics from LED lights to game consoles. Its overall usage has however been restricted due to its inability to process more energy, the researchers contend.
“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 minimising power loss and can dissipate heat efficiently. To achieve this, adding beryllium into gallium nitride – or ‘doping’ it – shows great promise,” explains Professor Filip Tuomisto.
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 and research on beryllium was largely discarded.
Researchers at Aalto University, along with scientists in Texas and Warsaw, have now managed to show – thanks to advances in computer modelling and experimental techniques – that beryllium can actually perform useful functions in gallium nitride.
Their article published in Physical Review Letters 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.
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.
Image and content: Hanna Koikkalainen/Aalto University