Research on residual gas adsorption on surface of InGaAs photocathode
Research on residual gas adsorption on surface of InGaAs photocathode
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InGaAs光电阴极表面残留气体吸附研究
DOI：
10.1016/j.ijleo.2018.11.039
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发表时间：
2019
期刊：
影响因子：
3.1
通讯作者：
Long Li
中科院分区：
文献类型：
--
作者：
Guo Jing;Yang Mingzhu;Zhao Jing;Huan Jiacai;Long Li
负电子亲和势InGaAs光电阴极是红外真空探测器的重要组成部分。本文重点研究了InGaAs光电阴极制备过程中残余气体的吸附问题。计算并讨论了吸附物对负电子亲和力产生的影响。基于第一性原理，建立了含有残余气体的InGaAs表面模型，并对其功函数、电荷转移、偶极子和形成能进行了分析。从表面到残余气体分子的偶极子是通过电荷转移产生的。表面功函数随之上升。最大增量达到0.410eV，这是由CO2的吸附引起的。光电子逃逸受到抑制。因此，提出了三种化学清洗方法来清洁InGaAs表面。研究发现，氧化物比其他残留气体分子更容易被擦掉。因此需要进一步治疗。
The negative electron affinity InGaAs photocathode is an important part of the infrared vacuum detector. The article focuses on the adsorption of residual gas in the preparation of InGaAs photocathodes. The impact of the adsorbates on the generation of negative electron affinity was calculated and discussed. Models of InGaAs surface with residual gas were built and the work function, charge transfer, dipole and the formation energy have been analyzed based on the first principles. The dipole from the surface to the residual gas molecule was generated by the charge transfer. The surface work function went up followed. The biggest increment came up to 0.410 eV, which is caused by the adsorption of CO2. The photoelectrons escape was restrained. As a result, three chemical cleaning methods were proposed to clean the InGaAs surface. It is found that oxide is more stable to be wiped off than the other residual gas molecule. So a further treatment needs to be raised.