Superlattice semiconductor photocathode for the electron beam source with a high brightness and a long NEA-surface lifetime.

点击翻译按钮获取中文摘要

The aim of this study is the realization of the novel electron source using a semiconductor photocathode with high brightness and long NEA-surface-lifetime. This study found that the quantum confinement effect in a superlattice structure has the advantage of small energy spread of extracted electrons and the semiconductor which has small electron affinity and large band-gap energy had the advantage of long NEA-surface-lifetime. The p-GaN photocathode with a bulk structure for the long NEA-surface-lifetime and the InGaN-GaN superlattice photocathode for the generation of photoelectrons with small energy spread ware developed. As a successful result, the p-GaN photocathode achieved ten times longer lifetime than the GaAs photocathode with a bulk structure known as the conventional photocathode and the effective quantum confinement effect was observed by the quantum yield spectrum of the InGaN-GaN superlattice photocathode.