Opportunities and future directions for Ga₂O₃

The β-polytype of Ga₂O₃ has a bandgap of ~4.8 eV, can be grown in bulk form from melt sources, has a high breakdown field of ∼8 MV.cm−¹ and is promising for power electronics and solar blind UV detectors, as well as extreme environment electronics (high temperature, high radiation, and high voltage (low power) switching. High quality bulk Ga₂O₃ is now commercially available from several sources and n-type epi structures are also coming onto the market. There are also significant efforts worldwide to grow more complex epi structures, including β-(Al_xGa_1x)₂O₃/Ga₂O₃ and β-(In_xGa₁−_x)₂O₃/Ga₂O₃ heterostructures, and thus this materials system is poised to make rapid advances in devices. To fully exploit these advantages, advances in bulk and epitaxial crystal growth, device design and processing are needed. This article provides some perspectives on these needs.