Abstract

Considering that it is impractical to utilize in situ surface diagnostic means to determine the surface cleanliness of transmission-mode GaAs photocathodes in the vacuum device manufacturing process, the thermal desorption technique with the aid of the quadrupole mass spectrometer during the thermal cleaning process is employed to in situ characterize the thermal cleaned surface. The desorption behaviors for various impurity gases during the thermal cleaning process are analyzed. The experimental results show that the amount of desorbed impurity gases varies due to the different heat treatment temperatures. Through the verification of Cs/O activation and quantum efficiency measurement, it is found that the desorption behaviors of the specific impurity gases including AsH3 and As2 are crucial to surface cleanliness of transmission-mode GaAs photocathodes, which relate to the final photoemission capability. This simple and reliable criterion provides an effective way to guide the thermal cleaning process of transmission-mode GaAs photocathodes, and the desorption behaviors assist in in situ evaluation of surface cleanliness.

© 2019 Optical Society of America

Full Article  |  PDF Article
OSA Recommended Articles
Improved activation technique for preparing high-efficiency GaAs photocathodes

Yijun Zhang, Yunsheng Qian, Cheng Feng, Feng Shi, Hongchang Cheng, Jijun Zou, Jingzhi Zhang, and Xiang Zhang
Opt. Mater. Express 7(9) 3456-3465 (2017)

Effect of surface cleaning on spectral response for InGaAs photocathodes

Muchun Jin, Yijun Zhang, Xinlong Chen, Guanghui Hao, Benkang Chang, and Feng Shi
Appl. Opt. 54(36) 10630-10635 (2015)

High quantum efficiency transmission-mode GaAlAs photocathode with a nanoscale surface structure

Xinlong Chen, Guanghua Tang, Dongchen Wang, and Pengxiao Xu
Opt. Mater. Express 8(10) 3155-3162 (2018)

References

You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Figures (6)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Equations (4)

You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Metrics

You do not have subscription access to this journal. Article level metrics are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription