Regensburg 2010 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

DS: Fachverband Dünne Schichten

DS 31: Molecular Spintronics - Current Status and Challenges I (Focused Session)

DS 31.3: Vortrag

Donnerstag, 25. März 2010, 11:30–11:45, H2

Engineering of the energy level alignment at organic semiconductor interfaces by intra-molecular degrees of freedom: transition metal phthalocyanines — •Mandy Grobosch¹, Victor Y. Aristov^1,2, Olga V. Molodtsova¹, Christian Schmidt¹, Brian P. Doyle^3,4, Stefano Nannarone³, and Martin Knupfer¹ — ¹IFW Dresden, D-01069 Dresden, Germany — ²nstitute of Solid State Physics, Russian Academy of Sciences, Moscow, Russia — ³University of Johannesburg, PO Box 524 Auckland Park — ⁴TASC-INFM Laboratory Trieste, Italy

The fact, that the transition metal ion in the central cavity of the Pc's can have a magnetic moment is a characteristic feature of TMPc's, and therefore these phthalocyanines can also show fascinating magnetic properties. We have determined the energy level alignment at interfaces between various transition metal phthalocyanines and gold using photoemission spectroscopy. Our results demonstrate that the transition metal center has a strong influence on the electronic properties of the phthalocyanine films as well as their interfaces with gold. This offers a route to adjust the hole injection barrier via the choice of otherwise equivalent molecular organic semiconductors. In particular, the interfaces MnPc/Au and CoPc/Au are characterized by a small hole injection barrier, which would be advantageous for applications. These are directly related to the presence of metal 3d states closest to the chemical potential; a fact that is also reflected in smaller ionization potentials for MnPc and CoPc as compared to other phthalocyanines. For details see: M. Grobosch et al., J. Phys. Chem. C 113, 13219 (2009).