[en] The energetics, atomic geometry, and electronic structure of semipolar (11-22) and (11-2-2) AlN surfaces are investigated employing first principles calculations. For metal-rich growth conditions, metallic reconstructions are favoured on both polarity surfaces. For N rich to moderate Al rich conditions, the (11-22) planes promote semiconducting reconstructions having 2 × 2 or c(2 × 2) periodicity. In contrast, under the particular range of the Al chemical potential the (11-2-2) surfaces stabilize reconstructions with excess metal and it is only at the extreme N rich limit that the semiconducting c(2 × 2) N adatom structure prevails. The present study reveals that the reconstructed (11-22) surfaces do not contain steps in contrast to (11-2-2) where surface steps are inherent for N rich to moderate metal rich growth conditions and may result in intrinsic step-flow growth and/or growth of parasitic semipolar orientations.
Research center :
Aristotle University of Thessaloniki
Disciplines :
Physics
Author, co-author :
Kalesaki, Efterpi ; University of Luxembourg > Faculty of Science, Technology and Communication (FSTC) > Physics and Materials Science Research Unit
Lymperakis, Liverios; Max-Planck-Institut fur Eisenforschung > Computational Materials Design Department
Kioseoglou, Joseph; Aristotle University of Thessaloniki > Department of Physics
Neugebauer, Jorg; Max-Planck-Institut fur Eisenforschung > Computational Materials Design Department
Karakostas, Theodoros; Aristotle University of Thessaloniki > Department of Physics
Komninou, Philomela; Aristotle University of Thessaloniki > Department of Physics
Language :
English
Title :
Reconstructions and electronic structure of (11-22) and (11-2-2) semipolar AlN surfaces
Publication date :
06 July 2012
Journal title :
Journal of Applied Physics
ISSN :
0021-8979
Publisher :
American Institute of Physics, Melville, United States - New York