CoPc/F16CuPc on Ag(100): Triggering the condensation of a 2D molecular gas

Description

When metal phthalocyanine molecules are deposited on metallic surfaces, they often form a 2D molecular gas in the submonolayer regime: Instead of a fixed position as in a condensed phase such as 2D islands, they are very mobile on the surface and change frequently their adsorption sites and geometry. The reason for this is a so-called surface-mediated repulsion, which may stabilizes the 2D gas phase even far beyond a coverage of 0.5 ML. This repulsion can be compensated by using mixtures of hydrogen- and fluorine-termined phthalocyanines. Here, we use photoelectron emission microsopy (PEEM) to investigate ultrathin films of cobalt-Pc (CoPc) and perfluorinated copper-Pc (F16CuPc) on Ag(100) surfaces. By following the evolution of the standard deviation1 of the image sequences acquired during subsequent deposition of the molecules, the 2D molecular gas and the condensed bi-molecular phase can be identified. Regardless of the sequence of deposition, first CoPc and then F16CuPc or vice versa, we can trigger the condensation of the 2D gas into a dense structure with a 1:1 ratio of the two molecules. The mixing of the molecules is actually not limited to the first layer on the substrate.

Period	19 Mar 2024
Event title	87. Jahrestagung der DPG und DPG-Frühjahrstagung der Sektion Kondensierte Materie (SKM)
Event type	Conference
Location	GermanyShow on map