Field emission properties of carbon nanotube cathodes prepared by different transfer methods

The effects of field emission properties of carbon nanotube(CNT) cathodes on indium tin oxide(ITO) transparent-film were investigated,which were prepared by screen-printing,spraying and electrophoretic deposition methods and sintered with high temperature.The morphologies of CNT cathodes prepared by different transfer methods were observed by scanning electron microscope(SEM),and the field emission properties were characterized in the same condition.The results show that three kinds of CNT cathodes have different field emission properties.The field emission tests indicate that the turn on electric field of the CNT cathodes prepared by screen-printing method is 2.21 V/μm,the one prepared by spraying method is 1.61 V/μm,and the one prepared by electrophoretic deposition method is 1.85 V/μm.When the electric field is 2.3 V/μm,it can be speculated that the field emission property of the CNT cathode prepared by spraying method take precedence over the other two,and the one prepared by screen-printing is the worst.The results were analyz by the metal semiconductor theory.