Electronic structure and molecular orientation of pentacene thin films on ferromagnetic La0.7Sr0.3MnO3
2010 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 81, no 20, 205415-1-205415-6 p.Article in journal (Refereed) Published
Pentacene thin films deposited on a ferromagnetic electrode, La0.7Sr0.3MnO3 (LSMO), have been studied using near-edge x-ray absorption fine structure (NEXAFS), ultraviolet photoemission spectroscopy (UPS), and atomic force microscopy (AFM). Here we present electronic structure and molecular orientation of pentacene thin film on LSMO. No evidence related to covalent bonding or significant charge transfer between pentacene and LSMO has been found in the NEXAFS or UPS results. UPS measurements suggest that the vertical ionization potential of pentacene on LSMO is 4.9 eV. Our results extracted from NEXAFS indicate that molecular long axis of pentacene stands on the LSMO substrate surface with a tilt angle of about 22 degrees +/- 2 degrees between the main molecular axis and the substrate surface normal. AFM images show the terracelike crystalline grain formed by stacking pentacene crystalline layers and a rough crystal-layer spacing of 14-15 angstrom. Findings deduced from UPS, NEXAFS, and AFM consistently demonstrate that pentacene stands on LSMO with a tilt angle.
Place, publisher, year, edition, pages
American Physical Society , 2010. Vol. 81, no 20, 205415-1-205415-6 p.
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-57165DOI: 10.1103/PhysRevB.81.205415ISI: 000278144500091OAI: oai:DiVA.org:liu-57165DiVA: diva2:323558
Original Publication: Fenghong Li, Patrizio Graziosi, Qun Tang, Yiqiang Zhan, Xianjie Liu, Valentin Dediu and Mats Fahlman, Electronic structure and molecular orientation of pentacene thin films on ferromagnetic La0.7Sr0.3MnO3, 2010, PHYSICAL REVIEW B, (81), 20, 205415. http://dx.doi.org/10.1103/PhysRevB.81.205415 Copyright: American Physical Society http://www.aps.org/2010-06-112010-06-112014-03-27Bibliographically approved