Metastable-atom desorption and luminescence stimulated by low-energy electron impact on condensed Kr, Xe, and Xe/Kr films

Mann A., Leclerc Grégoire, Sanche Léon. 1992. Metastable-atom desorption and luminescence stimulated by low-energy electron impact on condensed Kr, Xe, and Xe/Kr films. Physical review B. Condensed matter A, 46 (15) : 9683-9690.

Résumé : Metastable-atom desorption and uv luminescence from thin films of Kr and Xe on Pt(111) stimulated by impact of monochromatic low-energy electrons (E=5-25 eV, ?E=60 meV) have been studied. For either pure rare-gas film, the excitation function of the total luminescence signal shows two broad peaks that are presumably related to the interplay between creation of excitons and free-electron-hole pairs. Metastable-particle desorption is very weak for pure Kr and not detectable for pure Xe over the entire range of electron energies. However, for 35-ML Kr films covered with 1-ML Xe (ML denotes monolayer), a considerable signal due to metastable-particle desorption is observed. The energy dependence of the signal in the 8-12.6-eV region leads to an interpretation of the desorption in the form of two different mechanisms with different thresholds. The first one is based on the creation of a Xe exciton in a Kr environment, while in the second scheme the excitation energy is transferred from a Kr bulk exciton to a Xe atom at the Kr-Xe interface. In both cases, repulsive Kr-Xe* interaction near the film surface is postulated to eject a metastable Xe* atom.

Mots-clés Agrovoc : luminescence, rayonnement ultraviolet, désorption, film

Classification Agris : U30 - Méthodes de recherche

Auteurs et affiliations

• Mann A., Université de Sherbrooke (CAN)
• Leclerc Grégoire, Université de Sherbrooke (CAN)
• Sanche Léon, Université de Sherbrooke (CAN)

Source : Cirad - Agritrop (https://agritrop.cirad.fr/561368/)

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