Ultrawide Bandgap Semiconductors: State of the Art and Technological Challenges

Ultrawide bandgap (UWB) semiconductors are emerging as key enablers for next-generation high-power, high-frequency electronic devices, capable of operating in extreme conditions. This review article presents a comprehensive overview of the state-of-the-art of the three most investigated UWB materials: β-gallium oxide (β-Ga2O3), diamond, and aluminum nitride (AlN). First, intrinsic material properties and technological details (including bulk growth and epitaxy) are analyzed and discussed. Next, recent progress in the development of diodes and transistors for power and RF applications is discussed and critically analyzed, taking into account material-specific features and challenges. Finally, a comparison of different technologies is presented, highlighting the key advantages and drawbacks of each, and providing insights into other emerging material systems.