Vertical GaN diode shows resistance to proton irradiation
USTC team reports vertical GaN PiN diode featuring blocking voltage higher than 1.7 kV after high-energy proton irradiation
GaN power devices can bring many advantages to aerospace applications owing to the high switching frequency and low power losses. However, GaN power devices are still subject to degradation in reverse blocking and/or forward conduction performance when exposed to fluxes of high-energy protons from solar flares or Van Allen radiation belts.
Now researchers from University of Science and Technology of China (USTC) have demonstrated a vertical GaN PiN diode with a reverse blocking voltage (BV) higher than 1.7 kV after high-energy proton irradiation, which the team believes is the best among state-of-the-art quasi- and fully-vertical GaN power diodes.
The team investigated the impact of 10-MeV and 50-MeV proton irradiation with fluence up to 1×1014 cm–2 on vertical GaN-on-GaN PiN diode, which can maintain a BV higher than 1.7 kV (at 10–4 A/cm2) after the high-energy and high-dose proton irradiation. Meanwhile, conductivity modulation in the vertical GaN PiN diode still exists yet weakened after proton irradiation.
Moreover, the correlation between the electrical performance and the irradiation-induced recombination centres in the direct-bandgap GaN device has been revealed by using voltage-dependent electro-luminescence (EL) characterisations.
Figured above: (a) reverse I–V characteristics of the fresh and irradiated GaN PiN diode. (b) EL spectrum of proton irradiated GaN PiN diode at varying voltage in semi-log scale.
Reference
‘kV-Class Vertical GaN PiN Diode Under Proton Irradiation: Impact on Conductivity Modulation’ by Xuan Xie, Shu Yang at al., IEEE Electron Device Letters, vol. 46, no. 3, Mar. 2025.
