112 Int. J. Nanotechnol., Vol. 6, Nos. 1/2, 2009
Copyright © 2009 Inderscience Enterprises Ltd.
Model spectroscopic study of cobalt phthalocyanine
thin film interfaces with inorganic substrates
F. Petraki and S. Kennou*
Department of Chemical Engineering,
University of Patras and FORTH/ICE-HT,
Rion, Patras, Gr-26504, Greece
E-mail: petraki@chemeng.upatras.gr
E-mail: kennou@chemeng.upatras.gr
*Corresponding author
Abstract: Model experiments concerning the interface formation between
Cobalt Phthalocyanine (CoPc) ultra thin films and inorganic substrates
(ITO and Au) were carried out by using X-ray and Ultra-Violet photoelectron
spectroscopies (XPS, UPS). Organic films of controlled thickness were
deposited under ultrahigh vacuum conditions. From valence band
measurements on the growing films, the CoPc Highest Occupied Molecular
Orbital (HOMO) cut-off was determined ~0.80 eV from the analyser Fermi
level, whereas the work function of the CoPc film was found to be
4.40 ± 0.10 eV on both substrates. The experimental results show that CoPc
forms non-reactive interfaces with Au and ITO. The interfacial energy level
alignment of CoPc/ITO and CoPc/Au was derived from the photoemission
spectroscopic results and a hole injection barrier of ~0.80 eV was obtained for
both interfaces.
Keywords: CoPc; ITO; Au; XPS; UPS; interface; dipole; barriers;
work function.
Reference to this paper should be made as follows: Petraki, F. and Kennou, S.
(2009) ‘Model spectroscopic study of cobalt phthalocyanine thin film
interfaces with inorganic substrates’, Int. J. Nanotechnol., Vol. 6, Nos. 1/2,
pp.112–123.
Biographical notes: Foteini Petraki graduated from the Department of
Physics at the University of Patras in Greece in 2003 and she is now a
PhD student at the Department of Chemical Engineering at the University of
Patras in Greece.
Stella Kennou is an Associate Professor in the Material Science and
Technology Division at the Department of Chemical Engineering, University
of Patras, Greece. She has a BS and PhD in Physics from the University of
Ioannina and has developed extensive collaborations with many European
research institutions. The main emphasis of her work is on surface and interface
properties of electronic materials.