Effect of ambient temperature and cathode-anode separation on electron field emission property of carbon nanofibers thin films

Abstract

Carbon nanofibers (CNFs) thin films were prepared by using Radio frequency assisted plasma enhanced chemical vapor deposition (RF-PECVD) technique. Nickel thin films have been used for preparation of CNFs thin films, which stimulates the growth. The identification and confirmation of the graphitic phase of CNFs thin films were confirmed by using X-Ray Diffractometer. Nanostructure surface morphology of the CNFs thin films have been investigated by an Atomic Force Microscope, which reveals that the typical diameter of the CNFs was ∼ 180 nm with length of several micrometers. The electron field emission properties of CNFs thin films have been carried out for different cathode–anode separation and for various ambient temperatures. It was observed that with the extent of cathode–anode separation from 70 to 210 μm, the turn-on field was reduced to 3.5 V/μm from 4.4 V/μm respectively. Temperature dependent electron field emission measurement showed that the turn-on field was reduced to 2.3 V/μm from 4.2 V/μm, as ambient temperature of CNFs thin films was increased from 30 °C to 250 °C respectively. The field enhancement factor and turn-on field were calculated and demonstrate the electron emission procedure.