Investigation of Factor Causing Deterioration of Ferroelectric Electron Emitter

A factor causing deterioration of a ferroelectric electron emitter with a unique porous electrode has been investigated. In an electron emitter that deteriorates upon continuous operation, a decrease of the remnant polarization and a discoloration of the ferroelectric layer were observed. Furthermore, the binding energies of the elements comprising the layer were shown to have shifted to a higher energy when the ferroelectric layer was analyzed by X-ray photoelectron spectroscopy (XPS). These results indicate polarization fatigue caused by oxygen vacancies in the ferroelectric layer. Therefore, we considered that the main factor causing deterioration of our electron emitter is polarization fatigue in the ferroelectric layer. On the basis of these investigations, we applied a new ferroelectric material supplemented with 1 wt % MnO2 to prevent the degradation of the ferroelectric layer, which resulted in the durability of the electron emitter improving significantly.