Site-dependent charge transfer at the Pt(111)-ZnPc interface and the effect of iodine
2014 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 140, no 17, 174702- p.Article in journal (Refereed) Published
The electronic structure of ZnPc, from sub-monolayers to thick films, on bare and iodated Pt(111) is studied by means of X-ray photoelectron spectroscopy, X-ray absorption spectroscopy, and scanning tunneling microscopy. Our results suggest that at low coverage ZnPc lies almost parallel to the Pt(111) substrate, in a non-planar configuration induced by Zn-Pt attraction, leading to an inhomogeneous charge distribution within the molecule and an inhomogeneous charge transfer to the molecule. ZnPc does not form a complete monolayer on the Pt surface, due to a surface-mediated intermolecular repulsion. At higher coverage ZnPc adopts a tilted geometry, due to a reduced molecule-substrate interaction. Our photoemission results illustrate that ZnPc is practically decoupled from Pt, already from the second layer. Pre-deposition of iodine on Pt hinders the Zn-Pt attraction, leading to a non-distorted first layer ZnPc in contact with Pt(111)-I(root 3x root 3) or Pt(111)-I(root 7x root 7), and a more homogeneous charge distribution and charge transfer at the interface. On increased ZnPc thickness iodine is dissolved in the organic film where it acts as an electron acceptor dopant.
Place, publisher, year, edition, pages
2014. Vol. 140, no 17, 174702- p.
Charge distribution, Charge transfer, Electronic structure, Iodine, Molecules, Monolayers, Photoelectrons, Scanning tunneling microscopy, Thick films, X ray absorption spectroscopy, X ray photoelectron spectroscopy, Zinc, Electron acceptor, Intermolecular repulsions, Nonplanar configuration, Organic films, Pre-deposition, Second layer, Sub-monolayers, Tilted geometry
Other Physics Topics
IdentifiersURN: urn:nbn:se:kth:diva-147044DOI: 10.1063/1.4870762ISI: 000336048000034ScopusID: 2-s2.0-84900031581OAI: oai:DiVA.org:kth-147044DiVA: diva2:728913
FunderSwedish Energy AgencySwedish Research CouncilCarl Tryggers foundation
QC 201506232014-06-252014-06-232015-06-23Bibliographically approved