Demonstration of mechanically exfoliated <i>β</i>-Ga2O3/GaN p-n heterojunction

Abstract

This work demonstrates the construction of p-n heterojunctions between mechanically exfoliated beta-phase gallium oxide (β-Ga2O3) and p-GaN. The detailed mechanical exfoliation process was developed and can be used for further device applications. The atomic force microscopy study showed that the exfoliated β-Ga2O3 flakes had a very smooth surface with a roughness of 0.65 nm. Transmission electron microscopy revealed a clearly defined interface between the exfoliated β-Ga2O3 and p-GaN. The p-n heterojunction exhibited a turn-on voltage of 3.6 V and a rectification ratio of ∼105. The heterojunction also showed good thermal performance up to 200 °C. Ideality factors and turn-on voltages decrease with temperature, tending toward the ideal threshold voltage of 3.2 V as determined by Silvaco simulations. This work provides valuable information on a mechanically exfoliated β-Ga2O3/GaN p-n heterojunction, which opens up the opportunities for a variety of photonic and electronic applications.