梯度掺杂结构GaN光电阴极的激活工艺研究

Activation technique of gradient-doping GaN photocathode

利用自行研制的光电阴极多信息量测试评估系统,在线测试了梯度掺杂结构GaN光电阴极在激活过程中的光电流、Cs源电流和O源电流。根据激活后的阴极光谱响应曲线和量子产额曲线,分析了超高真空室真空度、激活前的阴极表面净化程度、激活中首次进Cs量、激活中的Cs/O比以及Cs/O源在激活中的供给方式等对阴极激活的影响,提出了梯度掺杂结构GaN光电阴极的优化激活工艺。

The data,such as photocurrents,currents of Cs source and O source in the activation process of gradient-doping GaN photocathode,were measured in the preparation and evaluation system designed by us.The effects of vacuum,surface cleaning,the first flux of Cs,Cs/O ratio,and Cs/O flux on/off were analyzed based on the curves of spectral response and quantum yield obtained by testing the gradient-doping GaN photocathode after being fully activated.The optimized activation technique of gradient-doping GaN photocathode was presented in detail at last.