Site-dependent charge transfer at the Pt(111)-ZnPc interface and the effect of iodine
| Autor: | Ahmadi, S., Agnarsson, B., Bidermane, I., Wojek, B. M., Noël, Q., Sun, C. H., Göthelid, M. |
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| Rok vydání: | 2014 |
| Předmět: | |
| Zdroj: | J. Chem. Phys. 140, 174702 (2014) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1063/1.4870762 |
| Popis: | 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 (XPS), X-ray absorption spectroscopy (XAS) and scanning tunneling microscopy (STM). 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 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 $\left(\sqrt{3}\times\sqrt{3}\right)$ or Pt(111)-I $\left(\sqrt{7}\times\sqrt{7}\right)$, 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. Comment: 12 pages, 9 figures |
| Databáze: | arXiv |
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