The influence of surface topography on the field emission of nanostructured copper oxide thin films grown by oblique incidence deposition

We report the surface morphology dependent enhanced field electron emission properties of copper oxide thin films, which are sputter deposited at two different incidence angles. The turn-on field is as low as 1.3 V mu m(-1) for obliquely deposited thin film, with an enhancement factor of similar to 5144. The emission current also shows good stability. With the help of finite element method analysis, we show that the enhanced field emission behaviour is due to the special surface topography of obliquely deposited film. While for the normally deposited film the screening effect plays an important role and thereby condemning the electron emission performance. We expect to have a general applicability of this study in the design of thin film based electron emitters.