Enhanced field emission from cerium hexaboride coated multiwalled carbon nanotube composite films: a potential material for next generation electron sources

Abstract

Intensified field emission (FE) current from temporally stable cerium hexaboride (CeB₆) coated carbon nanotubes (CNTs) on Si substrate is reported aiming to propose the new composite material as a potential candidate for future generation electron sources. The film was synthesized by a combination of chemical and physical deposition processes. A remarkable increase in maximum current density, field enhancement factor, and a reduction in turn-on field and threshold field with comparable temporal current stability are observed in CeB₆-coated CNT film when compared to pristine CeB₆ film. The elemental composition and surface morphology of the films, as examined by scanning electron microscopy, transmission electron microscopy, and energy dispersive X-ray measurements, show decoration of CeB₆ nanoparticles on top and walls of CNTs. Chemical functionalization of CNTs by the incorporation of CeB₆ nanoparticles is evident by a remarkable increase in intensity of the 2D band in Raman spectrum of coated films as compared to pristine CeB₆ films. The enhanced FE properties of the CeB₆ coated CNT films are correlated to the microstructure of the films.