Ⅲ族氮化物光电阴极原位程序升温脱附（英文）  

In situ temperature programmed desorption of Ⅲ-nitride photocathode

作　　者：成伟 石峰 杨书宁 周玉鉴 任彬 Cheng Wei;Shi Feng;Yang Shuning;Zhou Yujian;Ren Bin(Science and Technology on Low-Light-Level Night Vision Laboratory,Xi′an 710065,China;Kunming Institute of Physics,Kunming 650223,China)

机构地区：[1]微光夜视技术重点实验室,陕西西安710065 [2]昆明物理研究所,云南昆明650223

出　　处：《红外与激光工程》2019年第10期211-217,共7页Infrared and Laser Engineering

基　　金：国防预先研究基金(9140C380502150C38002)

摘　　要：建立了理论热脱附和原位程序升温脱附方法研究Ⅲ族氮化物光电阴极部件的热除气过程。基于Malev吸附-扩散除气理论搭建了光电阴极的平板模型,利用Fick第一和第二定理计算得到了除气过程中样品吸附气体浓度、瞬时除气速率以及总的气体脱附量随时间变化的表达式。为便于直观研究,通过截取四阶近似给出不同扩散系数量级下的以上参量随时间的变化曲线。在Ⅲ族氮化物光电阴极TPD动态法实验中,研究并分析了光电阴极部件在不同恒温除气阶段的残余气体谱图,由此得出进入真空中的脱附气体种类。采用最小二乘法拟合得到:恒温1 000 K的条件下,N2的扩散系数为5×10-5cm2/s。通过理论分析结合TPD实验,Ⅲ族氮化物光电阴极部件热清洗的有效去除污染加热温度得到了有效的评估和验证。Theoretical thermal desorption and in situ temperature programmed desorption(TPD) were developed to study the degassing of contaminants adsorbed in Ⅲ-nitride photocathodes assembly. In the frame of Malev′ sadsorption-diffusion outgassing theory, one dimensional slab was used to model the photocathodes assembly. By using the first and the second Fick′ slaw, the expressions of the special gas concentration, the specific gas outgassing rate and the amount of degased specific gas over the time in the degassing process were obtained. To make it more intuitional, these parameters were ploted over time within different diffusion coefficient magnitude at the approximation of fourth order. In the TPD method for Ⅲ-nitride photocathodes assembly, residual gas mass spectrum was thoroughly studiedat different constant temperature stage to determine which gases were desorbed into the vacuum. The least square method was employed to fit the expression of the specific outgassing rate at the constant temperature of 1 000 K, and the diffusion coefficient D for outgassing N2 was 5 ×10-5 cm2/s in the dynamic method of degassing process. By combining theoretical analysis with TPD experiments, the heating up temperature for sufficient outgassing the contaminants from the Ⅲ-nitride photocathodes assembly was evaluated and verified.

关 键 词：Ⅲ族氮化物光电阴极部件 程序升温脱附 残余气体谱 

分 类 号：TN216[电子电信—物理电子学]