The carbon nanotube(CNT) field emission cathodes based on different thin film substrate electrodes are prepared by electrophoretic deposition(EPD).The morphologies of CNT cathodes after being sintered under high temperature are observed by field emission scanning electron microscope(FESEM),which show that CNTs are uniformly distributed on the substrate electrodes.The field emission properties of CNT cathodes are influenced by substrate electrode materials obviously.The turn-on electric field of the CNT cath...