Electric Field Dependence of Photoemission from n- and p-type Si Crystals
- The performance of free electron lasers depends on the brilliance of the electron source. Nowadays photo-cathodes (e.g. Cs2Te) are used despite of their high emittance. To develop robust and more brilliant cathodes we have built up an UHV system which enables systematic photoemission (PE) measurements with a tunable pulsed laser (hv) at high electric fields (E). First results on Au and Ag crystals revealed only low quantum efficiency (QE) due to fast electron relaxation. Hence, we have started QE(hv,E) investigations on n- and p-Si wafers. Resonant PE was observed above as well as below the work function O, which can be assigned to optical transitions in the electronic band structure or explained by thermally excited states at the bottom of the conduction band. As expected, only low QE values were achieved even for n-Si probably due to surface oxide. Moreover, a significant rise of the QE peaks above O were obtained for n-Si at E >8 MV/m but limited by the occurrence of parasitic field emission from dust particles.
Author: | Stephan Mingels, Benjamin Bornmann, Dirk Lützenkirchen-HechtORCiD, Güntner Müller, Christoph LangerORCiD, Christian PrommesbergerORCiD, Rupert SchreinerORCiDGND |
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ISBN: | 9783954501267 |
Parent Title (English): | Proceedings, 35th International Free Electron Laser Conference (FEL 2013) : New York, NY, USA, August 26-19, 2013 |
Publisher: | Curran |
Place of publication: | Red Hook, NY |
Editor: | Caitlin Scholl, Volker R.W. Schaa |
Document Type: | conference proceeding (article) |
Language: | English |
Year of first Publication: | 2013 |
Release Date: | 2022/12/10 |
First Page: | 339 |
Last Page: | 343 |
Institutes: | Fakultät Angewandte Natur- und Kulturwissenschaften |
Fakultät Angewandte Natur- und Kulturwissenschaften / Labor Mikrosensorik | |
research focus: | Produktion und Systeme |
Licence (German): | Keine Lizenz - Es gilt das deutsche Urheberrecht: § 53 UrhG |