Structure and electronic properties of oxidized surfaces of GaN(0001)
The structure and electronic properties of oxidized (0001) surfaces of GaN grown by plasma-assisted molecular beam epitaxy are investigated by scanning tunneling microscopy/spectroscopy, Auger electron spectroscopy, and first-principles theory. For oxygen exposure at room temperature an amorphous Ga2O3 layer is found to form on the surface, having a band gap of about 2 eV and with tails of states extending into this gap. For oxidation at 550 degrees C ordered Ga2O3 surface structures form.
Dong, Y.; Feenstra, R. M.; Northrup, J. E. Structure and electronic properties of oxidized surfaces of GaN(0001). Applied Physics Letters. 2006 October 23; 89 (17): 171920.