Electronic and magnetic properties of pure and Cu doped non-polar ZnO (101¯0) surfaces

Abstract

In the present work, the electronic and magnetic properties of pure and Cu doped ZnO thin films in the non-polar [101¯0] direction have been investigated in the framework of density functional theory. The bandgap of pure surface was slightly lower than that of the bulk. By doping Cu impurity in the surface, the bandgap decreased relative to that of the pure surface, which is in the visible light region. Furthermore, the spin up and down behaved differently, presenting half-metallic behavior with a net magnetization as large as 1 μB/cell. These results imply that Cu doped ZnO surface can be applicable in spintronic and optical applications. By including O vacancy in Cu doped surface configurations, the bandgap was decreased leading to the metallic behavior. Furthermore, different magnetization was obtained for each configuration. It states that the presence of O vacancy in Cu doped ZnO surface may affect the induced magnetization in ZnO thin films.