Surface reconstructions on InN and GaN polar and nonpolar surfaces

We report a systematic and comprehensive computational study of surface reconstructions on GaN and InN surfaces in various orientations, including the polar c plane as well as the nonpolar a and m planes. For GaN we have identified several new metallic reconstructions under highly Ga-rich conditions on the nonpolar planes. For InN we find several distinct differences from the GaN case: the absence of a nitrogen-adatom reconstruction on the (0001) plane; the presence of a single, metallic reconstruction over the entire stability range on the (000 (1) over bar) plane; and In-adlayer reconstructions on the (1 (1) over bar 00) (m) plane. An interesting inverted polarity defect structure on the (1 (1) over bar 00) (m) plane is also revealed. (c) 2006 Elsevier B.V. All rights reserved.