【Device Papers】Gallium Oxide Schottky Barrier Diodes for Extreme-Temperature Power and Optoelectronic Devices

      Researchers from Korea Aerospace University have published a dissertation titled " Gallium Oxide Schottky Barrier Diodes for Extreme-Temperature Power and Optoelectronic Devices " in Progress in Quantum Electronics.

Abstract

      Gallium oxide (Ga₂O₃) has emerged as a promising ultra-wide-bandgap semiconductor for extreme-temperature electronics operating beyond the thermal limits of conventional devices. Its wide bandgap of 4.7–5.3 eV results in an exceptionally low intrinsic carrier concentration (∼10^-26 cm^-3) and a high critical electric field (∼8 MV/cm), enabling low leakage current, high breakdown strength, and stable operation at elevated temperatures. This review comprehensively examines Ga₂O₃ Schottky barrier diodes (SBDs) for high-temperature power and optoelectronic applications, with emphasis on temperature-dependent material properties and critical device parameters, including Schottky barrier height, leakage current, and breakdown voltage. Comparison with GaN indicates that, although Ga₂O₃ SBDs possess superior intrinsic material properties, the practical development of power devices remains constrained by low thermal conductivity, Schottky-interface instability, premature breakdown, and limited long-term reliability under high electric fields and current densities. In contrast, Ga₂O₃ SBDs have demonstrated exceptional performance as solar-blind ultraviolet (200–280 nm) and X-ray (1–20 keV) detectors, maintaining photosensitivity above 10⁵ μC·Gy^-1·cm^-2 and photo-to-dark current ratios above 10² at 573 K without active cooling. This difference arises because Ga₂O₃ power devices require high-quality substrates, robust interfaces, effective thermal management, and high-voltage packaging, resulting in greater fabrication complexity and cost. In contrast, optoelectronic devices exploit the intrinsically low carrier concentration and wide-bandgap absorption of Ga₂O₃ at low or moderate bias and can be fabricated as thin films on relatively low-cost sapphire substrates. These advantages have allowed Ga₂O₃ optoelectronic devices to progress more rapidly toward practical deployment, whereas power-device applications remain constrained by reliability, thermal management, and manufacturing cost.

DOI：

https://doi.org/10.1016/j.pquantelec.2026.100658