Dynamic characteristics of PdCoO₂/β-Ga₂O₃ Schottky junctions

A high-frequency diode is an essential component in electrical circuits providing the current rectification function for AC/DC converters, radio frequency detectors, and automotive inverters. Schottky barrier diodes based on wide-bandgap semiconductors are promising for the high-frequency applications owing to short reverse recovery time that minimizes the energy dissipation during the switching. In this study, we report dynamic characteristics of Schottky junctions composed of a layered oxide metal PdCoO₂ and an n-type β-Ga₂O₃ substrate. Rectifying current–voltage characteristics with reasonably small hysteresis were demonstrated up to a high frequency of 3 MHz in the PdCoO₂/β-Ga₂O₃ Schottky junctions. For the on-state to off-state switching with the current ramp rate of approximately −2 × 10¹⁰ A/scm², the reverse recovery time was as short as 11 ns. The short reverse recovery time was constantly obtained in the operation temperature range of 25–350 °C, showing low-loss switching properties of the PdCoO₂/β-Ga₂O₃ Schottky junctions. The Schottky barrier height of ∼1.78 eV and the ideality factor of ∼1.06 were maintained after the 10⁸-times on–off switching cycles. The fast switching with less energy dissipation and high durability of the PdCoO₂/β-Ga₂O₃ Schottky junctions would be suitable for application in high-frequency power devices operating at high temperature.