Journal Article

FZJ-2020-04755

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Evaluation of molecular orbital symmetry via oxygen-induced charge transfer quenching at a metal-organic interface

Cojocariu, I.FZJ* ; Sturmeit, H. M. ; Zamborlini, G. ; Cossaro, A. ; Verdini, A. ; Floreano, L. ; D'Incecco, E. ; Stredansky, M. ; Vesselli, E. ; Jugovac, M. ; Cinchetti, M. ; Feyer, V. (Corresponding author)FZJ* ; Schneider, C. M.FZJ*

2020
Elsevier Amsterdam

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Please use a persistent id in citations: http://hdl.handle.net/2128/26439  doi:10.1016/j.apsusc.2019.144343

Abstract: Thin molecular films under model conditions are often exploited as benchmarks and case studies to investigate the electronic and structural changes occurring on the surface of metallic electrodes. Here we show that the modification of a metallic surface induced by oxygen adsorption allows the preservation of the geometry of a molecular adlayer, giving access to the determination of molecular orbital symmetries by means of near-edge X-ray absorption fine structure spectroscopy, NEXAFS. As a prototypical example, we exploited nickel tetraphenylporphyrin molecules deposited on a bare and on an oxygen pre-covered Cu(1 0 0) surface. We find that adsorbed atomic oxygen quenches the charge transfer at the metal-organic interface but, in contrast to a thin film sample, maintains the ordered adsorption geometry of the organic molecules. In this way, it is possible to disentangle π* and σ* symmetry orbitals, hence estimate the relative oscillator strength of core level transitions directly from the experimental data, as well as to evaluate and localize the degree of charge transfer in a coupled system. In particular, we neatly single out the σ* contribution associated with the N 1s transition to the mixed N 2px,y-Ni 3dx2-y2 orbital, which falls close to the leading π*-symmetry LUMO resonance.

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Contributing Institute(s):

1. Elektronische Eigenschaften (PGI-6)

Research Program(s):

1. 522 - Controlling Spin-Based Phenomena (POF3-522) (POF3-522)

Appears in the scientific report 2020

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Database coverage:
; ; ; Clarivate Analytics Master Journal List ; Current Contents - Engineering, Computing and Technology ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; Essential Science Indicators ; IF >= 5 ; JCR ; Nationallizenz ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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