Enhancement of field emission of carbon nanotubes arrays formed by self-assembled microspheres

In this paper, a novel design of CNTs arrays is studied to enhance the field emission by using self-assembled microspheres as mask. The schematics in both 3-D of the unclose-packed microspheres deposited on top of the catalyst on the substrate was shown. The unclose-packed microspheres can be formed by using self-assembled approaches. The microspheres act as the mask during the growth of CNTs, which enables the CNTs arrays to be formed between the microspheres. This design of the CNTs arrays leads to significant enhancement of the local electric field due to the suppression of the screening effect. The comparison of the local electric field for the CNTs arrays without and with microspheres was shown. The calculation of the local electric field is based on the finite element analysis. The CNTs arrays with microspheres as mask exhibit significant enhancement of the local electric field as compared to that of the conventional CNTs arrays. Note that the aspect ratio and density of CNTs are kept the same.