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Title: Low energy electron microscopy and Auger electron spectroscopy studies of Cs-O activation layer on p-type GaAs photocathode

Work function, photoemission yield, and Auger electron spectra were measured on (001) p-type GaAs during negative electron affinity (NEA) surface preparation, surface degradation, and heating processes. The emission current sensitively depends on work function change and its dependence allows us to determine that the shape of the vacuum barrier was close to double triangular. Regarding the NEA surface degradation during photoemission, we discuss the importance of residual gas components the oxygen and hydrogen. We also found that gentle annealing (≤100 °C) of aged photocathodes results in a lower work function and may offer a patch to reverse the performance degradation.
Authors:
 [1] ;  [2] ;  [3] ; ; ;  [2] ;  [4]
  1. Institute for Advanced Research, Nagoya University, Nagoya 4648603 (Japan)
  2. NCEM, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)
  3. (Brazil)
  4. Nagoya University Synchrotron Radiation Research Center, Nagoya 4648603 (Japan)
Publication Date:
OSTI Identifier:
22402604
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 17; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ANNEALING; AUGER ELECTRON SPECTROSCOPY; ELECTRON MICROSCOPY; GALLIUM ARSENIDES; HYDROGEN; LAYERS; NEA; OXYGEN; PHOTOCATHODES; PHOTOEMISSION; SHAPE; SURFACES; WORK FUNCTIONS