ION-SCATTERING STUDY OF THE ZN AND OXYGEN-TERMINATED BASAL-PLANE SURFACES OF ZNO

The zinc-terminated, ZnO(0001)-Zn, and the oxygen-terminated, ZnO(0001 )-O polar surfaces have been studied by low-energy alkali ion scatteri ng. Single scattering analysis shows that both surfaces exhibit a surf ace structure that is bulk-terminated. No evidence is found for regist ry shifts at the surface or substantial quantities of point defects su ch as Zn or O vacancies as may be expected to relieve charge imbalance at the surface. Comparison with the results of computer simulation co nfirms the bulk-terminated structure, but fails to quantify the interl ayer spacing. A less satisfactory agreement between experiment and com puter simulation is obtained for the Zn-terminated surface than for th e O-terminated surface. It is found that, due to interference of multi ple scattering from second and third layers, layer spacings cannot be trivially extracted from single scattering analysis. However, specific scattering conditions are identified for the oxygen-terminated surfac e, where spacing in the first O-Zn double layer can be obtained. This spacing is found to be nearly identical to the bulk value. Published b y Elsevier Science B.V.