ELECTRON SOURCE AND PRODUCTION METHOD THEREFOR

Provided is an electron source capable of suppressing the exhaustion of an electron-emitting material. According to the invention, the electron source has an electron-emitting material and an electron-emission limiting material covering the side surface of the electron-emitting material. The work function of the electron-emission limiting material is higher than the work function of the electron-emitting material, and the heat radiation rate of the electron-emission limiting material is lower than the heat radiation rate of the electron-emitting material. 提供种能够抑制电子发射材料的消耗的电子源。根据本发明，提供种电子源，其具有电子发射材料、以及覆盖所述电子发射材料的侧面的电子发射限制材料，所述电子发射限制材料的功函数高于所述电子发射材料的功函数，所述电子发射限制材料的热辐射率低于电子发射材料的热辐射率。