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

用于电子束源的超晶格半导体光电阴极，具有高亮度和长NEA表面寿命。

• 批准号: 21740305
• 负责人: NISHITANI Tomohiro
• 金额: $ 3.08万
• 依托单位: The Institute of Physical and Chemical Research
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Young Scientists (B)
• 财政年份: 2009
• 资助国家: 日本
• 起止时间: 2009 至 2011
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-21740305/
• 关键词: フォトカソード; 高輝度電子源; ガリウムヒ素半導体; 超格子半導体; 負電子親和力表面; 長寿命化; 高耐久化; スピン偏極電子源

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.

本研究的目的是利用具有高亮度和长NEA表面寿命的半导体光阴极实现新型电子源。研究发现，超晶格结构中的量子限域效应具有引出电子能量扩散小的优点，而电子亲合势小、带隙能大的半导体具有长的NEA表面寿命的优点。研制了具有长NEA表面寿命的体结构p-GaN光电阴极和产生小能散光电子的InGaN-GaN超晶格光电阴极。作为成功的结果，p-GaN光电阴极实现了比GaAs光电阴极长十倍的寿命，具有称为常规光电阴极的体结构，并且通过InGaN-GaN超晶格光电阴极的量子产率谱观察到有效的量子限制效应。