Every year it seems like we have another device to charge — laptops, smartphones, tablets, wearable electronics, electric cars and so on. Charging processes ubiquitously use power electronic switches to convert electricity from one form to another so that it can be used in these devices. As power electronics become increasingly part of how we move and consume electricity, the U.S. Department of Energy (DOE) is looking for new ways to make these devices more powerful, more efficient and more compact.
Semiconductors are a critical part of power electronic devices, which today, are most commonly made of silicon semiconductor. However, silicon gets less efficient as power demands increase, so new materials are needed as power electronics capabilities and performance continue to advance. Gallium nitride (GaN) is a promising new wide-bandgap (WBG) semiconductor material with properties that allow it to operate at higher voltages, frequencies and temperatures at higher efficiencies than silicon.
To achieve semiconductor power devices, specific impurities are added to the semiconductor materials to achieve structures called p-n junctions through a process called doping. However, the lack of effective doping processes for GaN WBG semiconductor materials currently obstructs the progress in creating these new and better power electronics devices based on these materials.
Yuji Zhao, assistant professor of electrical and computer engineering at Arizona State University’s Ira A. Fulton Schools of Engineering, is working to advance fundamental knowledge of selective area doping processes for GaN WBG semiconductors through a $1.5 million project selected by the DOE Advanced Research Projects Agency-Energy (ARPA-E) as part of its Power Nitride Doping Innovation Offers Devices Enabling SWITCHES (PNDIODES) program. The PNDIODES program aims to address technological gaps in GaN doping, a critical technical step to achieve high performance GaN power devices.