Improvement of field emission properties of ZnO nanorods array with spray-coated carbon nanotubes

The ZnO nano-rods/carbon nano-tubes (CNTs) composite was synthesized by spray-coating of CNTs on ZnO nano-rods array, pre-deposited in hydrothermal method on the glass substrate coated with indium tin oxides (ITO) films. The influence of the synthesis conditions on the microstructures and field emission properties was investigated. The composite was characterized with X-ray diffraction (XRD) and scanning electron microscopy (SEM). We found that the uniformly distributed ZnO nano-rods, 500 nm in diameter, stand vertically, whereas the CNTs lie flat on the substrates. Uniformly wrapping the tips of ZnO nano-rods with the homogenously dispersed CNTs significantly improved the field emission characteristics of the ZnO arrays. For instance, its onset field and field enhancement factor increased up to 0.96 V/μm and 9881, respectively. Possible mechanisms responsible for the property enhancement were also tentatively discussed. ©, 2015, Science Press. All right reserved.