A comparison between field-emission properties of three one-dimensional carbon materials

Electron field-emission characteristics from three types of one-dimensional carbon materials, including single-walled carbon nanotube (SWNT) rope, polyacrylonitrile-based carbon fiber tow, and carbon microtree, were compared. It is found that the SWNT rope exhibits the best field-emission (FE) properties of low-emission voltage, large field enhancement factor, and good stability, which are attributed to its perturbing nano-sized tip and numerous emission sites on the tip and body. Carbon microtree has the poorest FE property due to its high electrical resistivity. This work may provide useful information for the selection of cathode materials with good FE properties in the design of large current carbon-based FE cathodes.