5 A/1.17 kV NiO/$\beta$-Ga2O3 heterojunction power rectifier with high-temperature operation capability up to 548 K

Industrial power devices are required to conduct at least several amperes current in the on-state while blocking at least hundreds of volts in the off-state. In this work, high-temperature operational
$\text{NiO}/\beta-\text{Ga}_{2}\mathrm{O}_{3}$
vertical p-n heterojunction diodes (HJDs) with ampere-level forward current and kV -level reverse breakdown voltage
$(V_{b})$
have been demonstrated. The temperature-dependent current-voltage characteristics reveal that trap-assisted tunneling (TAT) current dominates the forward conduction mechanism of HJDs, while the leakage current is dominated by variable range hopping (VRH) mechanism under the high reverse bias. The resultant large-area (1×1 mm
²
) HJD rectifiers exhibit a superior forward on-state current of 5 A, a nearly-unity ideality factor and a large
$V_{b}$
of 1.17 kV operated at a high temperature up to 548 K. The low deterioration rate of forward on-state current (1.24 mA/K at 4 V) and
$V_{b}$
(0.95 V/K) with temperature implies high reliability of HJD, evidencing the promising potential of Ga
2
O
3
-based power diodes in harsh-environment power systems.