Thermal stability and interlayer exchange processes in heterolayers of TiOPc and PTCDA on Ag(1 1 1)
| Autor: | Peter Jakob, Laura Fernández, Sebastian Thussing |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Materials science
Absorption spectroscopy Annealing (metallurgy) Bilayer Stacking Infrared spectroscopy 02 engineering and technology 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Crystallography Adsorption Electron diffraction 0103 physical sciences General Materials Science Thermal stability 010306 general physics 0210 nano-technology |
| Zdroj: | Journal of Physics: Condensed Matter. 31:134002 |
| ISSN: | 1361-648X 0953-8984 |
| DOI: | 10.1088/1361-648x/aafcf8 |
| Popis: | Organic-organic interfaces, in particular donor-acceptor type heterointerfaces, represent central elements of organic electronic devices. Understanding and controlling their physical properties is key to improve and modify their performance. For this purpose we have investigated the structural properties and thermal evolution of molecular heterointerface model systems. Specifically, various stacked titanyl-phthalocyanine (TiOPc)-3,4,9,10-perylene-tetracarboxylic-dianhydride (PTCDA) heterolayers grown on Ag(1 1 1) have been examined using Fourier transform infrared absorption spectroscopy and spot-profile analysis low-energy electron diffraction. An accurate description of the thermal evolution and prevalence of the various phases of TiOPc and PTCDA is derived from the spectral signatures of the two molecular species explored in previous studies. Exceptionally high thermal stability is found for stacked heterolayers comprising TiOPc double layers with characteristic up-down arrangement of its axial Ti-O unit and single layers of PTCDA. Thereby, interlayer exchange is negligible in a wide temperature range ([Formula: see text] K). This is ascribed to attractive intermolecular interaction (dipole-dipole interaction, hydrogen bonding) among the TiOPc molecules oriented face-to-face within the TiOPc bilayer sheet. Stacked layers of comprising single layers of TiOPc and of PTCDA turn out to be thermally much less stable and more heterogeneous. In the course of their thermal evolution, a number of processes such as interlayer exchange, TiOPc double-layer formation and dewetting are encountered. |
| Databáze: | OpenAIRE |
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