Molecular orientation dependent energy levels at interfaces with pentacene and pentacenequinone
2006 (English)In: Organic electronics, ISSN 1566-1199, Vol. 7, no 6, 537-545 p.Article in journal (Refereed) Published
We used ultraviolet photoelectron spectroscopy (UPS) to investigate the energy level alignment at contacts between pentacene and Ag(1 1 1) in the presence of interfacial 6,13-pentacenequinone (PQ). Depending on the metal pre-coverage with PQ, we found evidence for three distinctly different interface morphologies and molecular orientations, accompanied by significant changes of the energy level alignment. Consequently, the hole injection barrier between pentacene and Ag(1 1 1) varied between 1.1 eV (pristine Ag) and 0.45 eV (5.4 nm PQ pre-coverage on Ag). In addition, our UPS results suggest that PQ can act as deep trap for electrons in a pentacene matrix. Depending on the exact mutual orientation of PQ and pentacene, the depth of these traps can be in the range of 0.2-0.75 eV. © 2006 Elsevier B.V. All rights reserved.
Place, publisher, year, edition, pages
2006. Vol. 7, no 6, 537-545 p.
Electronic structure, Interface, Organic semiconductor, Photoelectron spectroscopy
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-50064DOI: 10.1016/j.orgel.2006.07.010OAI: oai:DiVA.org:liu-50064DiVA: diva2:270960