1 April 1993 Photoemission stability of negative-electron-affinity GaAs photocathodes
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Proceedings Volume 1982, Photoelectronic Detection and Imaging: Technology and Applications '93; (1993) https://doi.org/10.1117/12.142004
Event: Photoelectronic Detection and Imaging: Technology and Applications '93, 1993, Beijing, China
Abstract
Photoemission stability of the negative electron affinity (NEA) GaAs-(Cs,O) photocathode activated with several cycles of alternate Cs and O2 adsorption at room temperature is mainly determined by the stabilization of the cesium and oxygen adlayer on the GaAs surface, and the bonding strength between this adlayer and the GaAs substrate. It is found that the light treatment (incident white light illumination) during or after the Cs and O2 activation process can improve the emission stability of the NEA GaAs-(Cs,O) cathodes. It is also found that the emission stability of the NEA GaAs-(Cs,O) cathodes is closely related to the electronic states of cesium and oxygen before being adsorbed on the GaAs surfaces, best result being obtained with cesium ions and excited oxygen molecules. In addition to the activation procedure and experimental results, some photoinduced reactions, e.g., photoinduced adsorption, desorption, excitation, dissociation, ionization, and surface migration and surface rearrangement of the cesium and oxygen adsorbates on or from GaAs surfaces are analyzed, and their effects on the emission stability of the NEA GaAs-(Cs,O) photocathodes are discussed.
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Tailiang Guo, Tailiang Guo, Huai Rong Gao, Huai Rong Gao, } "Photoemission stability of negative-electron-affinity GaAs photocathodes", Proc. SPIE 1982, Photoelectronic Detection and Imaging: Technology and Applications '93, (1 April 1993); doi: 10.1117/12.142004; https://doi.org/10.1117/12.142004
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