@article{oai:nagoya.repo.nii.ac.jp:00031338,
 author = {Sato, Daiki and Nishitani, Tomohiro and Honda, Yoshio and Amano, Hiroshi},
 issue = {1},
 journal = {Journal of Vacuum Science & Technology B},
 month = {Jan},
 note = {In this paper, the authors describe the effectiveness of thermal annealing in vacuum for quantum efficiency (QE) recovery from Cs/O-activated GaN and GaAs photocathodes. The QE of Cs/O-activated GaN photocathodes at 3.4 eV dropped from 1.0% to <0.001% upon exposure to nitrogen and then increased to 0.6% upon annealing. On the other hand, the QE of Cs/O-activated GaAs at 1.42 eV did not increase after annealing. In addition, after Cs/O activation, the sample was exposed to normal laboratory air and installed in an X-ray photoemission spectroscopy system. Upon annealing at 330 °C, three key results were confirmed as follows: (1) the work function decreased by 0.32 eV, (2) the chemical states of Cs 4d and Ga 3d were unchanged, and (3) the intensities of O 1s and C 1s on the high-binding-energy side decreased. In conclusion, the experimental results indicate that the annealing recovers the QE of Cs/O-activated GaN photocathode.},
 title = {Recovery of quantum efficiency on Cs/O-activated GaN and GaAs photocathodes by thermal annealing in vacuum},
 volume = {38},
 year = {2020}
}