Field emission characteristics study for ZnO-CNTs composites by the microwave plasma jet chemical vapor deposition system

The field emission (FE) properties of the carbon nanotubes (CNTs) grown on zinc oxide (ZnO) films have been reported in the present study. The ZnO films were first spun on a Si substrate by a spin coater, and then the grown CNTs were grown on the surface of the ZnO films by the microwave plasma jet chemical vapor deposition (MPJCVD) system. The experimental results showed that ZnO-CNT composite exhibited superior FE performance compared to that of CNTs and ZnO nanowires. The turn-on field of an emission device constructed with the ZnO-CNT composite was 0.31 V μm^-1, which was lower than that of the common CNTs and ZnO nanowires/nanorods. As the results of field emission tests, the CNTs on ZnO films could be a useful material in the emission applications.