Low-energy scale excitations in the spectral function of organic monolayer systems

Article

关键词: ELECTRONIC-STRUCTURE;    PHOTOEMISSION-SPECTROSCOPY;    NTCDA MONOLAYERS;    HUBBARD-MODEL;    METAL;    INTERFACES;    SURFACE;    RESOLUTION;    STATES;    LEVEL;   

DOI  :  10.1103/PhysRevB.85.161404

来源: SCIE

【 摘 要 】

Using high-resolution photoemission spectroscopy we demonstrate that the electronic structure of several organic monolayer systems, in particular 1,4,5,8-naphthalene tetracarboxylic dianhydride and copper-phthalocyanine on Ag(111), is characterized by a peculiar excitation feature right at the Fermi level. This feature displays a strong temperature dependence and is immediately connected to the binding energy of the molecular states, determined by the coupling between the molecule and the substrate. At low temperatures, the linewidth of this feature, appearing on top of the partly occupied lowest unoccupied molecular orbital of the free molecule, amounts to only approximate to 25 meV, representing an unusually small energy scale for electronic excitations in these systems. We discuss possible origins, related, e. g., to many-body excitations in the organic-metal adsorbate system, in particular a generalized Kondo scenario based on the single impurity Anderson model.

【 授权许可】

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