Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Progress in Gallium Oxide Field-Effect Transistors for High-Power and RF Applications



Ory Maimon, Qiliang Li


Power electronics are becoming increasingly more important as electrical energy constitutes 40 % of the total primary energy usage in the USA and is expected to grow rapidly with the emergence of electric vehicles, renewable energy generation, and energy storage. New materials better suited for high power applications are needed as the Si material limit is reached. Beta-phase gallium oxide (β-Ga2O3) is a promising ultra-wide bandgap (UWBG) semiconductor for high power and RF electronics due to its bandgap of 4.9 eV, large theoretical breakdown electric field of 6 MV cm-1 – 8 MV cm-1, and Baliga figure of merit of 3300, 3 – 10 times larger than that of SiC and GaN. Moreover, β-Ga2O3 is the only WBG material that can be grown from the melt, making large, high-quality, dopable substrates at low costs feasible. Significant efforts in high quality epitaxial growth of β-Ga2O3 and β-(AlxGa1-x)2O3 heterostructures has led to high-performance devices for high power and RF applications. In this report, we provide a comprehensive summary of the progress in β-Ga2O3 field-effect transistors (FETs) including a variety of transistor designs, channel materials, ohmic contact formation and improvements, gate dielectrics, and fabrication processes. Additionally, novel structures proposed by simulations and not yet realized in β-Ga2O3 are presented. Main issues such as defect characterization methods and relevant material preparation, thermal studies and management, and the lack of p-type doping with investigated alternatives are also discussed. Finally, major strategies and outlook for commercial use will be described and discussed.


Gallium Oxide, field-effect transistor, power semiconductor devices, radio frequency semiconductor devices, ultra wide bandgap semiconductor, UWBG


Maimon, O. and Li, Q. (2023), Progress in Gallium Oxide Field-Effect Transistors for High-Power and RF Applications, Materials, [online],, (Accessed July 18, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created December 18, 2023, Updated January 4, 2024