Ga ₂ O ₃ power diodes with high voltage/current ratings, superior dynamic performance, robust reliability, and potentially easy-to-implement are a vital milestone on the Ga ₂ O ₃ power electronics roadmap. In this letter, a better tradeoff between fast reverse-recovery and rugged surge-current capability has been demonstrated in NiO/Ga ₂ O ₃ p-n heterojunction diodes (HJDs). With the double-layered p-NiO design, the HJD exhibits superior electrostatic performances, including a high breakdown voltage of 1.37 kV, a forward current of 12.0 A with a low on-state resistance of 0.26 Ω, yielding a static Baliga's figure of merit (FOM) of 0.72 GW/cm ² . Meanwhile, the fast switching performance has been observed with a short reverse recovery time in nanosecond timescale (11 ns) under extreme switching conditions of di/dt up to 500 A/μs _. In particular, for a 9-mm ² HJD, a large surge current of 45 A has also been obtained in a 10-ms surge transient, thanks to the conductivity modulation effect. These results are comparable with those of the advanced commercial SiC SBDs and have significantly outperformed the past reported Ga ₂ O ₃ HJDs, fulfilling the enormous potential of Ga ₂ O ₃ in power applications.

The technical progress of Ga ₂ O ₃ power diodes is now stuck at a critical point where a lack of performance evaluation and reliability validation at the system-level applications seriously limits their further development and even future commercialization. In this letter, by implementing beveled-mesa NiO/Ga ₂ O ₃ p–n heterojunction diodes (HJDs) into a 500-W power factor correction (PFC) system circuit, high conversion efficiency of 98.5% with 100-min stable operating capability has been demonstrated. In particular, rugged reliability is validated after over 1 million times dynamic breakdown with a 1.2-kV peak overvoltage. Meanwhile, superior device performance is achieved, including a static breakdown voltage (BV) of 1.95 kV, a dynamic BV of 2.23 kV, a forward current of 20 A (2 kA/cm ² current density), and a differential specific on -resistance of 1.9 mΩ·cm ² . These results indicate that Ga ₂ O ₃ power HJDs are developing rapidly with their own advantages, presenting the enormous potential in high-efficiency, high-power, and high-reliability applications.

In this letter, we report 9-mm ² Ga ₂ O ₃ Schottky barrier diodes (SBDs) with a thin-body thickness of 70 $\mu \text{m}$ . By implementing substrate thinning strategy and dual field plate structures, the resultant device exhibits a high forward current of 20 A, a low differential on-resistance of 57 $\text{m}\Omega $ , a small subthreshold slope of 65 mV/dec and a decent breakdown voltage of 355 V. In particular, a robust electrothermal ruggedness is achieved, including a low junction-to-case thermal resistance of 1.48 K/W and a high surge current of 59 A. Such superior performance is further validated by performing 150-W system-level power factor correction circuit measurements, delivering a record-high conversion efficiency of 98.9%. These results reveal the promise of die-level structure thermal management of the Ga ₂ O ₃ SBDs for high-power applications.

In this letter, we report a quasi-vertical GaN junction barrier Schottky diode on low-cost sapphire substrate. With the high quality GaN epitaxy and selective-area p-islands formed via Magnesium ion implantation at the anode region, reverse leakage in level of 10 ^-7 A/cm ² was achieved, as well as a high on/off current ratio of 10 ¹⁰ and a high breakdown voltage of 838 V. Meanwhile, advantageous characteristics as expected in vertical GaN Schottky barrier diode were realized, including a low turn-on voltage of 0.5 V and fast switching performance under 400 V/10 A operation condition. Along with the improved heat dissipation via substrate thinning and packaging techniques, the diode retains a relatively low thermal resistance, enabling high current rectification level over 60 A, power efficiency up to 98.7 %, while maintaining low case temperatures.

In this Letter, we demonstrate a large-area (1-mm²) beveled-mesa p-NiO/β-Ga₂O₃ bipolar heterojunction diode (HJD) with a high Baliga's figure of merit of 1.84 (2.87) GW/cm² from DC (pulsed) measurements. Benefiting from the suppression of electric field crowing at the designed mesa edge and bipolar current conductivity modulation, the resultant device exhibits advantageous characteristics, including a low subthreshold slope of 65 mV/decade, a low DC (pulsed) differential specific on-resistance of 2.26 (1.45) mΩ cm², a high current density of 2 kA/cm², and a high breakdown voltage of 2.04 kV. In particular, the Ga₂O₃ HJD exhibits an 800 V/10 A extreme switching capability with 16.4-ns reverse recovery characteristics, as well as high operation stability at a high temperature of 200 °C. This work, thus, makes a significant step toward reaching the promise of a high figure-of-merit in β-Ga₂O₃ power devices.

This work demonstrates the robust single-event irradiation hardness in 650-V E-mode p-GaN HEMTs with source-connected buried metal structure. Such device design notably contributes to the removal of irradiation-induced holes accumulated in the reverse-biased p-GaN/ AlGaN/GaN (p-i-n) junction region, thereby improving irradiation robustness against single-event burnout (SEB). The resulting device exhibits significantly improved SEB voltages of 558 and 467 V under heavy ion linear energy transfer ( $LET_{\text {ion}}$ ) conditions of 75.7 and 86.3 MeV $\cdot $ cm2/mg, respectively, setting a new performance record for GaN-based power devices. Moreover, based on pulsed laser equivalent heavy ion irradiation system configured with a power switching circuit, a high power conversion efficiency of 95% is demonstrated under 77.6 LET PL, 300 W/500 kHz conditions. This work thus makes a significant step toward reaching the promise of GaN devices for radiation applications.