A hBN/Ga₂O₃ pn junction diode

The development of next-generation materials such as hBN and Ga₂O₃ remains a topic of intense focus owing to their suitability for efficient deep ultraviolet (DUV) emission and power electronic applications. In this study, we combine p-type hBN and n-type Ga₂O₃, forming a pseudo-vertical pn hBN/Ga₂O₃ heterojunction device. Rectification ratios > 10⁵ (300 K) and [Formula: see text]400 (475 K) are observed and are amongst the highest values reported to date for ultra-thin hBN-based pn junctions. The measured current under forward bias is ~2 mA, which we attribute to the shallow Mg acceptor level (60 meV), and 0.2 µA at -10 V. Critically, device performance remains stable and highly repeatable after a multitude of temperature ramps to 475 K. Capacitance-voltage measurements indicate widening the depletion region under increasing reverse bias voltage and a built-in voltage of 2.34 V is recorded. The hBN p-type characteristic is confirmed by Hall effect, a hole concentration of [Formula: see text] cm^-3 and mobility of 24.8 cm²/Vs is achieved. Mg doped hBN resistance reduces by >10⁸ compared to intrinsic material. Future work shall focus on the optical emission properties of this material system.