Electron emitting device and electromagnetic wave generating device using the same

摘要

Provided is an electron emitting device which can achieve high electron emission efficiency even in the case where excitation energy is low. The device includes a carbon nanotube layer which is formed on an SiC substrate and is made up of plural carbon nanotubes vertically oriented with respect to a surface of the SiC substrate; an MgO layer which is formed on and touches the carbon nanotube layer; an ohmic electrode which is connected to the carbon nanotube layer; an electrode which is facing the MgO layer with an air-gap between the MgO layer and the electrode; and a voltage source which applies a voltage between the electrode and the ohmic electrode.