逸出功测试与GaAs光电发射材料的激活

Work Function Measurement and the Activation Treatment of GaAs Photoemissive Material

采用铯氧多次交替激活可获得积分灵敏度高达１７００μＡ／ｌｍ、逸出功低至１．２～１．３ｅＶ的负电子亲和势ＧａＡｓ光电发射材料。本文介绍了ＧａＡｓ光电材料的激活系统及其逸出功测试系统，叙述了艳氧多次交替激活工艺，给出了激活过程中灵敏度与逸出功的变化曲线，分析了ＧａＡｓ光电材料导带上内光电子波函数的透射系数与逸出功之间的关系，最后讨论了逸出功测试在高性能ＧａＡｓ光电材料制备过程中的作用。

Negative electron affinity GaAsphotoemissive materials with maximumphotoemission sensitivity of 1700 μA/lm andminimum work function of 1.2～1. 3 eV wereactivated with cesium-oxygen for several cycles.Inthis paper,the activation experimental setup and thework function measurement system were deseribed,the cesium-oxygen activation technology of theGaAs photoemissive materials was devolped, the experimental results about photoemissionsensitivitise and work functions of GaAsphotoemissive materials during their activationprocesses were presented. By using a simplequantum model,the relationship betweentransmissivity of wave function of internal photoelectrons in the GaAs conduction band wasanalyzed.Finally,the roles of work functionmeasurements in the activation processess of GaAsphotoemissive materials were discussed briefly.