Clean and As-Covered Zinc-Blende GaN (001) Surfaces: Novel Surface Structures and Surfactant Behavior
Abstract
We have investigated clean and As-covered zinc-blende GaN (001) surfaces, employing first-principles total-energy calculations. For clean GaN surfaces our results reveal a novel surface structure very different from the well-established dimer structures commonly observed on polar III-V (001) surfaces: The energetically most stable surface is achieved by a Peierls distortion of the truncated \(1×1\) surface rather than through addition or removal of atoms. This surface exhibits a \(1×4\) reconstruction consisting of linear Ga tetramers. Furthermore, we find that a submonolayer of arsenic significantly lowers the surface energy indicating that As may be a good surfactant. Analyzing surface energies and band structures we identify the mechanisms which govern these unusual structures and discuss how they might affect growth properties.
- Publication:
-
Physical Review Letters
- Pub Date:
- April 1998
- DOI:
- 10.1103/PhysRevLett.80.3097
- arXiv:
- arXiv:cond-mat/9705111
- Bibcode:
- 1998PhRvL..80.3097N
- Keywords:
-
- Condensed Matter
- E-Print:
- 4 pages, 3 figures, to be published in Appears in Phys. Rev. Lett. (in print). Other related publications can be found at http://www.rz-berlin.mpg.de/th/paper.html