Photoinduced desorption of potassium atoms from graphite
1996 (English)In: Surface Science, ISSN 0039-6028, E-ISSN 1879-2758, Vol. 363, no 1-3, 247-251 p.Article in journal (Refereed) Published
We present an experimental and theoretical investigation of desorption of potassium atoms from the basal plane of graphite induced by photons with energies from 2 to 6 eV. The intensity of the photon flux employed in the measurements is low, and the observed photodesorption is a single-photon, non-thermal event. At monolayer coverage the photon-energy dependence of the cross section has a maximum at 4.8 eV. The experimental observations are interpreted in terms of a hot carrier mechanism, which involves attachment of optically excited substrate hot electrons to the empty 4s state of ionized potassium, and then desorption. The theory predicts a Gaussian line shape of the photoyield versus photon energy. Fitting the model parameters to the experimental data, we determine: (i) the potential energy for Gr + K+ and Gr + K-0; and (ii) the position (2.4 eV above the Fermi level) and width (0.15 eV) of the potassium 4s resonance, which is in good agreement with independent experimental observations.
Place, publisher, year, edition, pages
1996. Vol. 363, no 1-3, 247-251 p.
electron-solid interactions, scattering, diffraction, graphite, photochemistry, photon stimulated desorption, semiempirical models and model calculations, surface photochemistry
Other Physics Topics
IdentifiersURN: urn:nbn:se:uu:diva-235941DOI: 10.1016/0039-6028(96)00144-6ISI: A1996UZ62400035OAI: oai:DiVA.org:uu-235941DiVA: diva2:762468
International Symposium on Dynamical Quantum Processes on Solid Surfaces, SEP 20-25, 1995, TOYONAKA, JAPAN