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Observation of Cu surface inhomogeneities by multiphoton photoemission spectromicroscopy

Authors :
Mirko Cinchetti
Gerd Schönhense
Hans-Joachim Elmers
Gerhard H. Fecher
Andreas Oelsner
Source :
Applied Physics Letters. 83:1503-1505
Publication Year :
2003
Publisher :
AIP Publishing, 2003.

Abstract

The spatially resolved energy distribution of electrons emitted from a polycrystalline copper surface has been studied by multiphoton photoemission. Electron emission was induced by femtosecond laser excitation and detected by an emission electron microscope combined with a time-of-flight detector to allow spatially resolved energy analysis. The energy distributions obtained from small spots with strongly enhanced electron emission yield (so-called hot spots) turned out to be different from those measured for homogeneous surface regions. The latter directly reflect two photon photoemission spectra from Cu as was previously observed in spatially averaging experiments. The hot spots, however, are characterized by a slightly lower work function and a strongly enhanced intensity if excited by s-polarized light. The peak positions of these spectra do not depend on the photon energy as is characteristic for a true secondary process. This indicates a different electron emission mechanism in the hot spots compared to homogeneous surfaces.

Details

ISSN :
10773118 and 00036951
Volume :
83
Database :
OpenAIRE
Journal :
Applied Physics Letters
Accession number :
edsair.doi...........8dc0ed7db09befdd270dd45e3dcdce5c
Full Text :
https://doi.org/10.1063/1.1603332