Understanding the Adsorption of CuPc and ZnPc on Noble Metal Surfaces by Combining Quantum-Mechanical Modelling and Photoelectron Spectroscopy

Author(s)
Yu Li Huang, Elisabeth Wruss, David A. Egger, Satoshi Kera, Nobuo Ueno, Wissam A. Saidi, Tomas Bucko, Andrew T. S. Wee, Egbert Zojer
Abstract

Phthalocyanines are an important class of organic semiconductors and, thus, their interfaces with metals are both of fundamental and practical relevance. In the present contribution we provide a combined theoretical and experimental study, in which we show that state-of-the-art quantum-mechanical simulations are nowadays capable of treating most properties of such interfaces in a quantitatively reliable manner. This is shown for Cu-phthalocyanine (CuPc) and Zn-phthalocyanine (ZnPc) on Au(111) and Ag(111) surfaces. Using a recently developed approach for efficiently treating van der Waals (vdW) interactions at metal/organic interfaces, we calculate adsorption geometries in excellent agreement with experiments. With these geometries available, we are then able to accurately describe the interfacial electronic structure arising from molecular adsorption. We find that bonding is dominated by vdW forces for all studied interfaces. Concomitantly, charge rearrangements on Au(111) are exclusively due to Pauli pushback. On Ag(111), we additionally observe charge transfer from the metal to one of the spin-channels associated with the lowest unoccupied π-states of the molecules. Comparing the interfacial density of states with our ultraviolet photoelectron spectroscopy (UPS) experiments, we find that the use of a hybrid functionals is necessary to obtain the correct order of the electronic states.

Organisation(s)
Computational Materials Physics
External organisation(s)
National University of Singapore (NUS), Chiba University, Technische Universität Graz, University of Pittsburgh, Comenius University Bratislava, Slovenian Academy of Sciences and Arts
Journal
Molecules
Volume
19
Pages
2969-2992
No. of pages
24
ISSN
1420-3049
DOI
https://doi.org/10.3390/molecules19032969
Publication date
03-2014
Peer reviewed
Yes
Austrian Fields of Science 2012
103025 Quantum mechanics, 103036 Theoretical physics, 103015 Condensed matter, 103009 Solid state physics
Keywords
ASJC Scopus subject areas
Drug Discovery, Analytical Chemistry, Chemistry (miscellaneous), Molecular Medicine, Physical and Theoretical Chemistry, Pharmaceutical Science, Organic Chemistry
Portal url
https://ucrisportal.univie.ac.at/en/publications/understanding-the-adsorption-of-cupc-and-znpc-on-noble-metal-surfaces-by-combining-quantummechanical-modelling-and-photoelectron-spectroscopy(aede0c08-17de-480c-ab0c-fe488bcfdf55).html