Structural and chemical effects of charge transfer across metal organic interfaces

Abstract

Abstract In the present dissertation charge transfer at the interface between organic acceptors and a metal Cu(100)-single crystal surface is identified as one of the main factors in determining the molecular adsorption geometry, the possible surface reconstruction upon adsorption, the molecular ordering upon self assembly and the nature of the chemical reaction that the molecules can undergo when adsorbed on a metal surface. Four molecule-substrate systems are investigated with experimental techniques like STM, XPS, XAS and work function measurements, the findings are presented together with theoretical support. The results of this thesis evidence the inadequacy of the gas-phase picture in which the only role of the surface is supporting the adsorbates, while their interactions and geometries are those of the gas-phase. In particular, our experiments show that charge transfer at organic-metal interfaces, which is expected at many technologically relevant situations, affects in a very decisive way the morphology of the interface and must be taken into consideration in the atomic-scale engineering of such interfaces.