The stability of the CNT/Ni field emission cathode fabricated by the composite plating method

Autor: Bohr-Ran Huang, Ying-Kan Yang, Shien-Der Tzeng, Tzu-Ching Lin
Rok vydání: 2010
Předmět:
Zdroj: Diamond and Related Materials. 19:158-161
ISSN: 0925-9635
DOI: 10.1016/j.diamond.2009.10.012
Popis: A novel composite plating method has been developed for the fabrication of carbon nanotube/Ni (CNT/Ni) field emission cathode. The field emission properties of the initial CNT/Ni field emitter show a low turn-on electric field E on of about 1.1 V/μm with an emission current density of 1 μA/cm 2 , and a low threshold electric field E th of about 1.7 V/μm with an emission current density of 1 mA/cm 2 . After performing a stability test with a high emission current density in high vacuum, the corresponding microstructure and the degree of graphitization of the CNT/Ni field emitter were measured by using scanning electron microscopy and Raman spectroscopy. We found that the degree of graphitization slowly decreases with the duration time t FE of the stability test, the size of small rod-like CNT/Ni composite structures in the film increases with t FE , and obvious cracks appear in the film as t FE is larger than 60 h. The degradation of the field emission properties may be explained by the Joule heating effect on the CNT/Ni field emitter under high emission current density.
Databáze: OpenAIRE