Field emission properties of ZnO nanorods coated with NiO film

Abstract

The field emission (FE) properties of ZnO and NiO-coated ZnO (NiO∕ZnO) nanorods are investigated under vacuum of 7×10−7Torr and oxygen rich vacuum of 1×10−5Torr. The ZnO nanorods were synthesized on a Si(100) substrate by metal-organic chemical vapor deposition, and the NiO film with the thickness of ∼15nm was coated by using atomic layer deposition. The turn-on voltages of the NiO∕ZnO nanorod and the ZnO nanorod were ∼5.2 and ∼3.0V∕μm at 1μA∕cm2, respectively. The electron FE stability of the NiO∕ZnO nanorods to the ZnO nanorod was significantly improved in oxygen rich vacuum even.