Synthesis and characteristics of a monocrystalline GaAs/ fl-Ga 2 O 3 p-n heterojunction

Beta phase -gallium oxide (fl-Ga 2 O 3 ) is an emerging ultrawide bandgap semiconductor but lacks efficient p -type doping, which hinders development of high-performance bipolar heterojunction devices. This study introduces the synthesis and characterization of a monocrystalline GaAs/fl-Ga 2 O 3 p -n heterojunction, employing advanced semiconductor grafting technology. The heterojunction was innovatively fabricated by grafting a p -type GaAs single crystal nanomembrane to an Al 2 O 3 -coated n -type fl-Ga 2 O 3 epitaxial substrate. The synthesized heterojunction was comprehensively characterized. The band alignment of grafted GaAs/fl-Ga 2 O 3 p -n heterojunction was experimentally constructed through X-ray photoelectron spectroscopy (XPS), and the result is in accordance with the theorical prediction based on the electron affinity rule. The resulting GaAs/fl-Ga 2 O 3 p -n diodes built on this heterojunction exhibit remarkable performance metrics, including an ideality factor of 1.23, a high rectification ratio of 8.04 x 10 9 at +/- 4 V, and a turn on voltage at 2.35 V. Furthermore, at + 5 V, the diode displays a large current density of 2500 A/cm 2 along with a low ON resistance of 2 m Omega center dot cm 2 . This study marks the first successful demonstration of a high -quality grafted GaAs/fl-Ga 2 O 3 p -n heterojunction, establishing a critical building block for the further development of bipolar Ga 2 O 3 -based device applications such as diodes, transistors, and thyristors.