ZnO(000(1)over-bar)-O surface structure: hydrogen-free (1x1) termination

Core level photoemission, low energy electron diffraction, and high resolution electron energy loss spectroscopy have been used to probe the impact of surface contamination on the structure of ZnO(0001)-O. In contrast to recently reported studies [e.g. Phys. Rev. B 66 (2002) 081402, Phys. Rev. Lett. 90 (2003) 106102], which conclude that the commonly observed (1 x 1) surface termination is a result of surface hydroxyl formation, it is found that such a phase may be prepared without the presence of a significant concentration of surface -OH. We suggest that this discrepancy is most likely due to the use of different anneal temperatures during surface preparation. (C) 2004 Elsevier B.V. All rights reserved.