Journal of Vacuum Science & Technology B, Vol.16, No.4, 2242-2249, 1998
Reconstructions of GaN(0001) and (0001) surfaces : Ga-rich metallic structures
Reconstructions of GaN(0001) and (<000(1)over bar>) surfaces are studied by scanning tunneling microscopy and spectroscopy, by electron diffraction, by Auger electron spectroscopy, and using first-principles theory. Attention is focused on Ga-rich reconstructions for each surface, which are found to have a metallic character involving significant overlap between Ga valence electrons. The electron counting rule is thus violated for these surfaces, but they nonetheless form minimum energy structures.