High Current Cold Electron Source Based on Carbon Nanotube Field Emitters and Electron Multiplier Microchannel Plate

In this work, we report the synthesis and field emission properties of carbon nanotube multistage emitter arrays, which were grown on porous silicon by catalytic thermal chemical vapor deposition. The emitter structure consisted of arrays of multiwall nanotubes (MWNTs) on which single/thin-multiwall nanotubes were grown. The structure was confirmed by TEM and Raman analysis. Higher field emission current similar to 32 times and low threshold field similar to 1.5 times were obtained for these structures in comparison to only MWNT arrays. The enhanced field emission results for these multistage emitters are a consequence of higher field concentration, which was similar to 3 times more than only MWNTs. In this work we also report a novel method to amplify electron emission from field emitters by electron multiplication. A microchannel plate positioned between the emitter cathode and the anode was utilized to enhance the field emission current.