https://doi.org/10.1140/epje/i2005-10012-0
Original Article
The effect of oxygen exposure on pentacene electronic structure
1
Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung m.b.H., Albert-Einstein-Str. 15, D-12489, Berlin, Germany
2
Materials Science Center, Rijksuniversiteit Groningen, NL-9747 AG, Groningen, The Netherlands
3
Institut f. Physik, Humboldt-Universität zu Berlin, Newtonstr. 15, D-12489, Berlin, Germany
4
3. Physikalisches Institut, Universität Stuttgart, D-70550, Stuttgart, Germany
* e-mail: norbert.koch@physik.hu-berlin.de
Received:
18
February
2005
Accepted:
21
April
2005
Published online:
21
June
2005
We use ultraviolet photoelectron spectroscopy to investigate the effect of oxygen and air exposure on the electronic structure of pentacene single crystals and thin films. It is found that O2 and water do not react noticeably with pentacene, whereas singlet oxygen/ozone readily oxidize the organic compound. Also, we obtain no evidence for considerable p-type doping of pentacene by O2 at low pressure. However, oxygen exposure lowers the hole injection barrier at the interface between Au and pentacene by 0.25 eV, presumably due to a modification of the Au surface properties.
PACS: 73.20.Hb Impurity and defect levels; energy states of adsorbed species – / 79.60.Fr Polymers; organic compounds – / 79.60.Jv Interfaces; heterostructures; nanostructures –
© EDP Sciences, Società Italiana di Fisica and Springer-Verlag, 2005
