Dresden 2017 – wissenschaftliches Programm
CPP 46.3: Vortrag
Mittwoch, 22. März 2017, 15:30–15:45, CHE 91
Interface-Controlled DNTT Thin Films: Growth, Morphology, and Temporal Evolution — •Andrea Karthäuser1, Tobias Breuer1, Hagen Klemm2, Francesca Genuzio2, Gina Peschel2, Alexander Fuhrich2, Thomas Schmidt2, and Gregor Witte1 — 1FB Physik, Philipps-Universität Marburg, 35032 Marburg, Germany — 2Abt. Chemische Physik, FHI der MPG, 14195 Berlin, Germany
The high charge carrier mobility and chemical stability of dinaphthothienothiophene (DNTT) render this new organic semiconductor (OSC) especially interesting for organic field effect transistors (OFETs) [1, 2]. Despite such device advances, the structure and morphology of DNTT thin films are so far rather unexplored. On the prototypical substrates SiO2 and graphene we prove a substrate-mediated control of the molecular orientation by means of NEXAFS and XRD measurements. Furthermore, by using atomic force microscopy (AFM) and photoelectron emission microscopy (PEEM) we analyzed the morphology of DNTT films with variable thicknesses and find a temporal dewetting of these films. This pronounced island formation leads to a breakup of the film which is most efficient for thin films of a few monolayers. Finally we have extend this study also to device relevant substrates by analyzing DNTT films that were grown on SAM treated dielectrics. Again a district dewetting is found, which is expected to affect the long-term performance of DNTT devices and appears surprising in view of the reported long term stability of DNTT-OFETs .
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