Local Surface Potential of GaN Nanostructures Probed by KelvinForce Microscopy

We have measured the fluctuation in local surface potential of GaN epitaxial films having two different types of nanostructure, as-grown islands or etched pits, by Kelvin probe force microscopy. We found that the perimeters of as-grown islands and the internal walls of etchd pits have lower surface potential as compared to the as-grown c-plane. The results show that the crystallographic facets tilted with respect to c-plane have higher work function and are electrically more active than c-surface.