Abstract
Ultrawide-band-gap (UWBG) oxide semiconductors are emerging as key platforms for next-generation energy-efficient, high-power, and high-frequency electronics. Further performance gains require the discovery of alternative UWBG systems with band gaps well above 4 eV, while offering intrinsically higher carrier mobility and controllable dopability. This paper highlights recent computational predictions and experimental advances toward such materials, with a focus on dopant activation, carrier density control, and phonon-limited mobility. Although computational screening has uncovered numerous promising candidates, most have yet to be realized as high-quality, single-crystalline thin films suitable for scalable devicefabrication. While epitaxial growth offers a unique platform to probe the intrinsic properties of these materials, the experimental realization is often limited by kinetic and processing constraints, such as nucleation dynamics and precise control of growth parameters. This gap often leads to significant deviations from the theoretical ground-state electrical transport properties. We examine the origins of these discrepancies and highlight integrated approaches, combining high-throughput computation with advanced epitaxial synthesis, to accelerate the development of next-generation UWBG oxide semiconductors. GRAPHICAL ABSTRACT: [Image: see text] SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40580-026-00534-4.