A ferroelectric electron emitter having a vacuum gap

Abstract

SUMMARYA novel electron emitter utilizing the characteristics of ferroelectric ceramic materials has been developed. The electron-emitting portion of the electron emitter has a unique micro-structure which has the vacuum gap between an upper electrode and the surface of a ferroelectric layer. We confirmed electron emission by a three-step process which consists of electron charge (the first step), charge retention (the second step), and electron emission (the third step). The ferroelectric hysteresis in the process indicates unique characteristics as follows. At the first step, remnant polarization of the same level as the completely adhered electrode structure is obtained in spite of a vacuum gap because the electron charge develops from the upper electrode to the surface of the ferroelectric layer under the vacuum gap in synchronism with the polarization reversal of the ferroelectric layer. On the other hand, at the third step, the electric field in the vacuum gap advances electron emission while the development of the polarization reversal inhibits the return of the electron charge along the surface of the ferroelectric layer.