Data centre power usage could be radically cut with new gallium nitride semiconductors
Wed 29 Jul 2015
New research out of MIT signifies that gallium nitride (GaN) transistors could be modifiable to provide significant boons to resource usage in data centres, as well as long-range electric vehicles and smaller and lighter laptop power adaptors. Though the manufacturing principles for gallium nitride semiconductors have long been established, their conductive nature has traditionally defaulted to ‘on’ – a problem in regulating current flow.
Now new research from Cambridge Electronics Inc. (CEI), spun out of MIT’s entrepreneurial programs, has found a method to reverse this natural default, thereby allowing GaN-based semiconductor technology that if implemented widely could cut deeply into the 2% of total electricity usage in the United States that data centres currently consume. Additionally GaN technology, as envisaged by the research, could enable the niche market of all-electric cars to have a shot at mainstream take-up by extending the vehicles’ range and efficiency.
Gallium nitride is a binary III/V direct bandgap semiconductor crystal employed in LED lights and Blu-ray players. GaN-based materials have a high breakdown field, permitting operation at much higher voltages than other semiconductor configurations.
CEI co-founder Tomás Palacios says of the breakthrough “This is a once-in-a-lifetime opportunity to change electronics and to really make an impact on how energy is used in the world,”
The breakthrough was achieved by experimenting with varying materials of differing compositions in GaN transistors, eventually yielding an arrangement which permitted the long-desired ‘default off’ configuration. Of this stage of the work, Palacios said “We always talk about GaN – once described as ‘The superman of semi-conductors’ – as gallium and nitrogen, but you can modify the basic GaN material, add impurities and other elements, to change its properties,”
The team, which includes Joseph F. and Nancy P. Keithley Professor in Electrical Engineering Anantha Chandrakasan, were able to substitute the traditional use of gold in GaN circuitry for conventional silicon-based fabrication methods, ultimately delivering performance “100 times better”, according to CEI associate Bin Lu.
CEI has succeeded in creating laptop power adaptors with a record-breaking low volume of around 1.5 cubic inches. The group’s GaN output is also capable of surpassing the constrained power output ceiling on chargers in electric cars. This increased power output in electric vehicles would combine with lower weights to afford significantly longer ranges for such vehicles on a single charge. Palacios commented: “Electric vehicles are popular, but still a niche product. GaN power electronics will be key to make them mainstream,”