The photocurrent attenuation of GaAs photocathode within one hour after activation under three different vacuum pressure (5×10^-9Pa, 5×10^-8Pa, 5×10^-7Pa) were recorded by automatically activated monitor. The results show that: the photocurrent quickly descend in the beginning and then descend linearly at a low slope; the amplitude of the quickly descending area were 10%, 14.74% and 36%separately, with the respective slope of the linear descending area were -0.00653, -0.01132and -0.02. Three samples’ gas components of H₂, CH₄, CO, H₂O, O₂, CO₂ etc under the same vacuum pressure (5×10^-8Pa)during photocurrent attenuation were collected by quadrupole mass spectrometer. By comparing the gas components content and the attenuation law of the photocurrent, it has been found that H₂O and H₂ had a greater impact on the stability of GaAs photocathode in the ultra-high vacuum environment and H₂O was the predominant effect. This paper has important guiding significance and reference value in studying the stability of GaAs photocathode and the improvement of semiconductor photocathode process.

Date Published: 13 April 2015
PDF: 7 pages
Proc. SPIE 9522, Selected Papers from Conferences of the Photoelectronic Technology Committee of the Chinese Society of Astronautics 2014, Part II, 95220I (13 April 2015); doi: 10.1117/12.2178709

Published in SPIE Proceedings Vol. 9522:
Selected Papers from Conferences of the Photoelectronic Technology Committee of the Chinese Society of Astronautics 2014, Part II
Xiangwan Du; Jennifer Liu; Dianyuan Fan; Jialing Le; Yueguang Lv; Jianquan Yao; Weimin Bao; Lijun Wang, Editor(s)