Novel Stabilization Mechanism on Polar Surfaces: ZnO(0001)-Zn

O. Dulub, U. Diebold, G. Kresse

Department of Physics, Tulane University, New Orleans, Louisiana 70118, U.S.A.
Institut für Materialphysik and Centre for Computational Materials Science, Universität Wien, A-1090 Wien, Austria

Phys. Rev. Lett. 90 (2003) 016102

The (1×1) terminated (0001)-Zn surface of wurtzite ZnO was investigated with scanning tunneling microscopy. The surface is characterized by the presence of nanosized islands with a size-dependent shape and triangular holes with single-height, O-terminated step edges. It is proposed that the resulting overall decrease of the surface Zn concentration stabilizes this polar surface. Ab initio calculations of test geometries predict triangularly shaped reconstructions over a wide range of oxygen and hydrogen chemical potentials. The formation of these reconstructions appears to be electrostatically driven.

Reprints available from U. Diebold (diebold at iap_tuwien_ac_at).

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