Theory of Electronic Structure of the Polar ZnO Surface by the Cluster Models

Abstract

The electronic structures of polar ZnO srufaces are investigated by the use of the DV–Xα cluster calculations. The compensating charge of about 18∼28% of inner ionic charge is found to be induced on the polar surface of the cluster. The electronic origin of the charge compensation is discussed in detail. Drastic reduction of the ionic charge is revealed on the corner of the clusters, which is caused by the crossing of the surface level with the Fermi energy. Chemisorptions of oxygen and hydrogen on the ZnO polar surface are also studied by the cluster model.