Formation of cesium peroxide and cesium superoxide on InP photocathode activated by cesium and oxygen
Author(s) -
Yun Sun,
Zhi Liu,
P. Pianetta,
Dong-Ick Lee
Publication year - 2007
Publication title -
journal of applied physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.699
H-Index - 319
eISSN - 1089-7550
pISSN - 0021-8979
DOI - 10.1063/1.2786882
Subject(s) - photocathode , caesium , chemistry , x ray photoelectron spectroscopy , oxygen , peroxide , quantum yield , photochemistry , valence (chemistry) , inorganic chemistry , analytical chemistry (journal) , electron , fluorescence , optics , nuclear magnetic resonance , physics , organic chemistry , quantum mechanics , chromatography
Activation of p type III-V semiconductors with Cesium and Oxygen has been widely used to prepare Negative Electron Affinity (NEA) photocathodes. However, the nature of the chemical species on the surface after the activation is not well-understood. In this study, InP NEA photocathodes activated with Cesium and Oxygen are studied using Synchrotron Radiation Photoelectron Spectroscopy, also called photoemission. Based on the O1s core level as well as the valence band spectra, Cs peroxide and Cs superoxide are identified on the InP surface. Transformation from Cs peroxide to Cs superoxide is observed after the activation, and probably is the major reason for the decay of the Quantum Yield of the photocathode. The oxidation of the InP substrate is also observed with the elapse of time, adding to the decay of the Quantum Yield.
Accelerating Research
Robert Robinson Avenue,
Oxford Science Park, Oxford
OX4 4GP, United Kingdom
Address
John Eccles HouseRobert Robinson Avenue,
Oxford Science Park, Oxford
OX4 4GP, United Kingdom