Design of Ring-Assisted Junction Termination Extension for High-Voltage Vertical NiO/β-Ga₂O₃ p-n Heterojunction Diodes

p-NiO High critical E-field (E C , ~8 MV/cm) High temperature capability Potential low-cost substrate Low R on and capacitance Low intrinsic carrier density Melt-based bulk growth method Poor thermal conductivity (k T , ~20 W•m -1 •K -1 ) Absence of p-type Ga 2 O 3 Low electron mobility Self-heating effect induced poor performance No intrinsic p-type Ga 2 O 3 Lower than 4H-SiC and GaN drift layer with same doping level Cathode p-NiO n-Ga 2 O 3