Unusual energy shifts in resonant photoemission spectra of organic model molecules

H Peisert; I Biswas; L Zhang; B-E Schuster; M B Casu; A Haug; D Batchelor; M Knupfer; T Chassé

doi:10.1063/1.3138785

Unusual energy shifts in resonant photoemission spectra of organic model molecules

J Chem Phys. 2009 May 21;130(19):194705. doi: 10.1063/1.3138785.

Authors

H Peisert¹, I Biswas, L Zhang, B-E Schuster, M B Casu, A Haug, D Batchelor, M Knupfer, T Chassé

Affiliation

¹ IPTC, University of Tübingen, Auf der Morgenstelle 8, 72076 Tübingen, Germany. heiko.peisert@uni-tuebingen.de

PMID: 19466853
DOI: 10.1063/1.3138785

Abstract

We study the electronic structure of zinc phthalocyanine (ZnPc) and 1,4-octa-decyl substituted zinc phthalocyanine [(Dec)(8)PcZn] thin films (approximately 6-15 nm) using resonant photoemission spectroscopy and X-ray absorption spectroscopy (XAS) at room temperature and at liquid He temperature. From XAS we conclude that the probability amplitude of the lowest unoccupied molecular orbital is located predominantly at the inner C and N atoms of the molecules. Nonlinear energy shifts in resonant photoemission were observed; large shifts are explained by reduced electrical conductivity of inhomogeneously oriented molecules.