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Monte Carlo simulation study of Cs2Te
Gowri Adhikari1,7, Houjun Qian1,2, Peng-Wei Huang3, Mikhail Krasilnikov1, Matthias Gross1, Frank Stephan1, Sven Lederer6, Pavel Juarez6, Caterina Cocchi4, Holger-Dietrich Sassnick4, Daniele Sertore5, and Laura Monaco5
1 Deutsches Elektronen-Synchrotron DESY, Platanenalle 6, 15738 Zeuthen, Germany
2 Zhangjiang Laboratory, Shanghai 201210, China
3 Department of Engineering Physics, Tsinghua University, Beijing 100084, China
4 Carl von Ossietzky Universit¨at Oldenburg, Physics Department, D-26129 Oldenburg, Germany
5 Istituto Nazionale di Fisica Nucleare - LASA, Segrate, Italy
6 Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany
7 SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
The semiconductor photocathodes are very attractive because of their high quantum yield. The semiconductors that have a relatively large band gap (Eg) and a comparatively low electronic affinity (Ea) are considered good photo emitters [1]. Cs2Te is considered a robust high current photo emitter for FEL and particle accelerator applications [2]. In this contribution, a theoretical formulation of a three-step model [3] is developed, using the Density Functional Theory (DFT) and the Monte Carlo simulation [4]. The simulation includes the density of states (DOS) of the valence bands, the electron transport mechanisms, the direction changes after each scattering event, the Schottky effect, band bending effects, and the transverse momentum conservation. The model agrees well with measured results for thermal emittance, quantum efficiency, and response time data of Cs2Te.
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