氩对四针状氧化锌场发射性能的影响

摘要

氧化锌是一种宽带半导体材料,由于其具有负电子亲和势,高的机械强度和良好的化学稳定性等特性,也被认为是一种很有发展潜力的场发射阴极材料.但是由于阴极材料在纳米量级,纳米材料的一些效应使其对工作的环境气体非常敏感.氩是采用薄膜型吸气剂的电真空器件中常见的残余气体成份.采用充气实验法研究了氩对氧化锌场发射的影响,得出其对氧化锌的场发射电流具有增强作用.由于氩的引入在一定程度上对系统起到了清洗的作用,系统内对氧化锌具有衰减作用的气体减少从而使得氧化锌发射电流在相同外加电压下增加.%ZnO is a new type of semiconductor with large bandgap,has attracted extraordinary attention because of its negative electron affinity,high mechanical strength,and chemical stability,which allow it to be candidate cold cathode materials used in field emission devices.When cathode materials reach to nanoscale,special effects such as surface-interface effect will effects make them sensitive to the ambient gases.Argon is common in vacuum electronic devices with thin film getter.Argon was introduced into a ZnO field emission device amounted on an ultra high vacuum system.The results indicate that the emission currents of ZnO are enhanced after exposed to Ar condition.This enhancement is mainly due to the rather clean gas condition at the surface of the cathodes.Other physical adsorption gases such as CO,CO2 are desorbed under argon gas condition.