Vertical bonding distances and interfacial band structure of PTCDA on a Sn-Ag surface alloy
| Autor: | Johannes Knippertz, Martin Aeschlimann, Markus Franke, Christian Kumpf, Benjamin Stadtmüller, Mirko Cinchetti, Leah L. Kelly |
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| Rok vydání: | 2020 |
| Předmět: |
Materials science
Condensed Matter - Mesoscale and Nanoscale Physics Spintronics Alloy FOS: Physical sciences 02 engineering and technology engineering.material 021001 nanoscience & nanotechnology 01 natural sciences Surface energy Condensed Matter::Materials Science Adsorption X-ray photoelectron spectroscopy Chemical physics Mesoscale and Nanoscale Physics (cond-mat.mes-hall) 0103 physical sciences Physics::Atomic and Molecular Clusters engineering Molecule ddc:530 010306 general physics 0210 nano-technology Electronic band structure Single crystal |
| Zdroj: | Physical Review B Physical review / B 102(7), 075447 (2020). doi:10.1103/PhysRevB.102.075447 |
| ISSN: | 2469-9969 2469-9950 |
| DOI: | 10.1103/physrevb.102.075447 |
| Popis: | Molecular materials enable a vast variety of functionalities for novel electronic and spintronic devices. The unique possibility to alter organic molecules or metallic substrates offers the opportunity to optimize interfacial properties for almost any desired field of application. For this reason, we extend the successful approach to control metal-organic interfaces by surface alloying. We present a comprehensive characterization of the structural and electronic properties of the interface formed between the prototypical molecule PTCDA and a Sn-Ag surface alloy grown on an Ag(111) single crystal surface. We monitor the changes of adsorption height of the surface alloy atoms and electronic valence band structure upon adsorption of one layer of PTCDA using the normal incidence x-ray standing wave technique in combination with momentum-resolved photoelectron spectroscopy. We find that the vertical buckling and the surface band structure of the $\mathrm{Sn}{\mathrm{Ag}}_{2}$ surface alloy is not altered by the adsorption of one layer of PTCDA, in contrast to our recent study of PTCDA on a $\mathrm{Pb}{\mathrm{Ag}}_{2}$ surface alloy [B. Stadtm\"uller et al., Phys. Rev. Lett. 117, 096805 (2016)]. In addition, the vertical adsorption geometry of PTCDA and the interfacial energy level alignment indicate the absence of any chemical interaction between the molecule and the surface alloy. We attribute the different interactions at these PTCDA/surface alloy interfaces to the presence or absence of local $\ensuremath{\sigma}$-bonds between the PTCDA oxygen atoms and the surface atoms. Combining our findings with results from literature, we are able to propose an empiric rule for engineering the surface band structure of alloys by adsorption of organic molecules. |
| Databáze: | OpenAIRE |
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