Vollmer A, Jurchescu O D, Arfaoui I, Salzmann I, Palstra T T M, Rudolf P, Niemax J, Pflaum J, Rabe J P, Koch N
Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung m.b.H., Berlin, Germany.
Eur Phys J E Soft Matter. 2005 Jul;17(3):339-43. doi: 10.1140/epje/i2005-10012-0. Epub 2005 Jun 21.
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 O(2) 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 O(2) 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.