Site-dependent charge transfer at the Pt(111)-ZnPc interface and the effect of iodine
Artikel i vetenskaplig tidskrift, 2014

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.

Författare

S. Ahmadi

Kungliga Tekniska Högskolan (KTH)

Björn Agnarsson

Chalmers, Teknisk fysik, Biologisk fysik

I. Bidermane

Uppsala universitet

B. M. Wojek

Kungliga Tekniska Högskolan (KTH)

Q. Noel

Kungliga Tekniska Högskolan (KTH)

C. H. Sun

University of Queensland

M. Gothelid

Kungliga Tekniska Högskolan (KTH)

Journal of Chemical Physics

0021-9606 (ISSN) 1089-7690 (eISSN)

Vol. 140 174702

Ämneskategorier

Fysik

DOI

10.1063/1.4870762