Demonstration of gallium oxide nano-pillar field emitter arrays

We demonstrate field emission characteristics of β-Ga₂O₃ nano-pillar arrays fabricated using a damage-free etching technique. The technique utilizes Ga flux in an ultra-high vacuum environment (molecular beam epitaxy) to form high aspect ratio Ga₂O₃ nano-pillars with atomic-scale etching precision. Electrically conductive Ga₂O₃ nano-pillars with uniform widths of ∼200-300 nm were realized without the use of e-beam lithography. Furthermore, field emission characteristics on the nano-pillars displayed an emission current of 19 nA per tip at an electric field of 385 kV/cm. The field emission characteristics were modeled using the Murphy-Good model, and the measurements were validated with a field emission orthodoxy test.