Nanoparticle Filler Effect on Enhanced Field Electron Emission Properties of Carbon Nanotube Paste Emitters

The effect of nanoparticle fillers on the field electron emission properties of CNT paste emitters was investigated. Several nanoparticle fillers such as graphite, SiC, TiC, and Ni nanoparticles were used for fabricating the CNT paste emitters. By adding other nanoparticles like SiC, TiC or Ni nanoparticles to the graphite nanoparticle, the CNT paste emitter shows improved field electron emission properties. Especially, the CNT paste emitter made with the combination of graphite, TiC, and Ni nanoparticles exhibits the best field electron emission performance with a low turn-on electric field of 1.75 V/mu m, a low threshold electric field of 2.12 V/mu m, and a high emission current density of 1218.28 mA/cm(2) at an applied electric field of 4.6 V/mu m. It also presents good field electron emission stability with a small degradation rate of 10.68% and a small fluctuation rate of +/- 0.54% over 20 h. The result is caused by the increased electron emission sites of the CNT paste emitter, increased electrical conductivity of the CNT paste emitter, and decreased contact resistance between the CNT paste emitter and the Kovar substrate.