“There is growing demand for semiconducting GaN in the power electronics industry,” said Professor Filip Tuomisto. “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.” He added this can be achieved by doping GaN with beryllium.
Experiments with beryllium doping were conducted in the late 1990s, but the work proved unsuccessful and the research was largely discarded.
Now, in conjunction with with scientists in Texas and Warsaw, Aalto researchers have managed to show – via computer modelling and experimental techniques – that beryllium can perform useful functions in GaN. Their work is said to show that, depending on whether the material is heated or cooled, beryllium atoms will switch positions and either donate or accept electrons.
“Our results provide valuable knowledge for experimental scientists about the fundamentals of how beryllium changes its behaviour during the manufacturing process, Prof Tuomisto continued. “During it – while being subjected to high temperatures – the doped compound functions very differently than the end result,”
If beryllium-doped GaN structures and their electronic properties can be fully controlled, power electronics could move to a whole new realm of energy efficiency, Prof Tuomisto claimed. “The magnitude of the change in energy efficiency could be similar [to the move] to LED lights from traditional incandescent light bulbs. It could be possible to cut global power consumption by up to 10% by reducing the energy losses in power distribution systems.”