1.96 kV p-Cr2O3/<b> <i>β</i> </b>-Ga2O3 heterojunction diodes with an ideality factor of 1.07

In this Letter, we report on a p-Cr2O3/n-Ga2O3 vertical heterojunction diode (HJD) with a kilovolt-level breakdown voltage (BV). The chromium oxide (Cr2O3) film was deposited via magnetron sputtering, with a controlled thickness of approximately 20 nm and a hole concentration of 1 × 1016 cm−3. High-resolution transmission electron microscopy of the p-Cr2O3 film reveals a polycrystalline lattice structure. At room temperature, the 40 μm radius HJD exhibits a turn-on voltage (Von) of 1.7 V, a specific on-resistance (Ron, sp) of 4.6 mΩ·cm2, and a BV of 1.96 kV. Notably, the ideality factor (η) of the HJD is 1.07, the closest to 1 among all reported Ga2O3 HJDs, indicating a high-quality interface at the p-Cr2O3/n-Ga2O3 HJ. Additionally, the BVs at 75 and 150 °C are 1.63 and 1.4 kV, respectively, demonstrating the promising potential of p-Cr2O3/n-Ga2O3 HJDs for high-temperature and high-power applications.