Ultrawide‐Bandgap Semiconductors: Research Opportunities and Challenges

Ultrawide-bandgap (UWBG) semiconductors, with bandgaps significantly wider than the 3.4 eV of GaN, represent an exciting and challenging new area of research in semiconductor materials, physics, devices and applications. Because many figures-ofmerit for device performance scale nonlinearly with bandgap, these semiconductors have long been known to have potential compelling advantages over their narrowerbandgap cousins in high-power and RF electronics, as well as in deep-UV optoelectronics, quantum information, and extreme-environment applications. Only recently, however, have the UWBG semiconductor materials, such as high Al-content AlGaN, diamond and Ga2O3, advanced in maturity to the point where realizing some of their tantalizing advantages is a relatively near-term possibility. In this article, we survey, and present an enumerated list of, the materials, physics, device and associated application research opportunities and challenges that are believed to be important for advancing the state of their science and technology. These research opportunities and challenges emerged from a workshop, The Second Technical Exchange on Ultrawide-bandgap Semiconductors: Research Opportunities and Directions, held in Arlington, VA, April 24-25, 2016, which brought together leading experts from academia, government, and industry. DISTRIBUTION STATEMENT A: Approved for public release: distribution unlimited. This material is based upon work supported by the Assistant Secretary of Defense for Research and Engineering under Air Force Contract No. FA8721-05-C-0002 and/or FA8702-15-D-0001. Any opinions, findings, conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the Assistant Secretary of Defense for Research and Engineering.