Surge current capability of power diodes is one of the essential parameters that needs to be considered for high power density operations in power electronic applications. Gallium Nitride (GaN) is emerging as the next generation of power semiconductor devices due to its superior material characteristics. This work presents the device working principle, characteristics, and the surge capability of 1200V GaN polarisation superjunction (PSJ) hybrid diodes. The experimental results show that the GaN PSJ diode can withstand a surge current of 60A which is around 8 times its rated current and a surge energy of 5.4J. Additionally, despite having a merged PiN and Schottky structure, no bipolar current flow due to the activation of p-doped GaN can be observed until breakdown. This can also be confirmed through the device forward characteristic which shows a unique saturation behaviour at about 76A without any bipolar region.

Due to an error in the production process, an incorrect version of Fig. 5, which did not include blue shading, was published. The correct version of Fig. 5 is shown below. Fig. 5. (Color online) (a) Typical reverse recovery waveform and (b) test circuit for reverse recovery measurement.

Gallium Nitride (GaN) devices inherently offer many advantages over silicon power devices including higher operating frequency, lower on-state resistance, and higher operating temperature capabilities, which can enable higher power density, more efficient power electronics. Turn-off dV/dt controllability plays a key role in determination of common-mode voltage in electrical drives and traction inverters applications. The fast-switching edges of GaN can introduce challenges such as electromagnetic interference, premature insulation failures and high overshoot-voltages. In this paper, the device working principle, characteristics and dV/dt controllability of 1.2kV GaN polarisation superjunction (PSJ) heterostructure field effect transistors (HFET) are presented. The effect of gate driving parameters and load conditions on turn-off dV/dt are investigated. It is shown that, in PSJ HFETs, the dV/dt can be effectively controlled to as low as 1kV/µs by controlling the gate and with minimum increase in switching losses. These results are highly encouraging for their application into the motor drives.