Structure, interface, and luminescence of (011¯1) ZnO nanofilms

ZnO nanofilms of (011¯1) texture have been prepared by ion beam sputtering on the (001) surface of single-crystal NaCl. The orientation relationship between them is determined by transmission electron microscopy. Analyses of electron diffraction patterns and interface confirm that the ZnO (011¯1) plane is the interface with the NaCl (001) surface. The photoluminescence spectrum from the ZnO (011¯1) surface shows a near-band-edge UV emission and a broad green emission. The result indicates that the inherent high surface defects of oxygen vacancies on the (011¯1) surface are the probable origin of the green emission.