The carbon nanotubes (CNTs) synthesized at various reaction conditions (reaction temperature, gas environment, and the ratio of mixture gas) using catalytic chemical vapor deposition (CCVD) in a fluidized bed reactor have quite different properties according to their tube diameter and crystallinity. Macroscopic field emission properties of the CNT film have been determined by a vacuum field emission system that displays the integrated field emission using a phosphor ITO-glass screen. Field emission properties of multi-walled carbon nanotubes (MWCNTs) depend on their electrical conductivity and structural quality such as the tube diameter and crystallinity (ID/IG). The smaller the mean diameter and the higher the crystallinity of the CNTs, the better the field emission properties could be achieved.
