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DS: Dünne Schichten

DS 22: Postersitzung

DS 22.27: Poster

Dienstag, 9. März 2004, 14:30–17:00, Poster B

TOF-PEEM investigation of photoelectron emission from cesium covered silver nanoparticle films — •D.A. Valdaitsev, M. Cinchetti, A. Gloskovskii, S.A. Nepijko, and G. Schönhense — Johannes Gutenberg-Universität Mainz, Institut für Physik, Staudingerweg 7, D-55099 Mainz

The present study continues the time-of-flight photoemission electron microscopy investigation of emission properties of Ag nanoparticles under fs-laser excitation (hν=3.1 eV, Δ=80 fs, fluence 6.4 µJcm⁻²). Earlier it was demonstrated that the energy distribution of electrons emitted from the particles considerably differs from the well-known 2PPE spectrum typical for bulk silver [1]. To understand the emission mechanisms in more detail we studied the change of energy spectra of electrons emitted from the nanoparticle films (particle size from 1 to 50 nm) caused by deposition of Cs. This allows to observe switching between different electron emission mechanisms in the same system. Lowering of the work function led to the shift of the low-energy edge and allowed to consider the electron energy distribution in a wider range. Exponential behavior of the spectrum in the low-energy region points to a significant contribution of electron gas heating processes to the total emission yield from sufficiently small particles.

[1] M. Cinchetti, D.A. Valdaitsev, A. Gloskovskii, A. Oelsner, S.A. Nepijko, G. Schönhense, J. Elec. Spec. Relat. Phenom., in print