On the Origin of the Energy Gain in Epitaxial Growth of Molecular Films.
The material properties of organic thin films depend strongly on their order. The different types of epitaxy may complicate the exploration of the large variety of ordered systems and its exploitation in potential electronic devices. In this Letter, we develop a coherent description of the driving force that creates epitaxial systems. We focus on flat-lying organic adsorbates and explain the energy gain in commensurate, point-on-line, and line-on-line epitaxy. We use potential energy maps to visualize our concept and to derive a relation that allows anticipating epitaxial growth from low-energy electron diffraction (LEED) data. A unified description facilitates the identification and interpretation of experimentally observed adsorbate structures, whereas the rationalized expectation from LEED means a considerable speed gain if suitable candidates for organic-organic epitaxy are searched for in a combinatory approach.
Christian
C
Wagner
§Institut für Festkörperphysik, Friedrich Schiller Universität Jena, 07743 Jena, Germany.
Roman
R
Forker
§Institut für Festkörperphysik, Friedrich Schiller Universität Jena, 07743 Jena, Germany.
Torsten
T
Fritz
LEED; epitaxy; organic adsorbates; organic heterostructures; potential energy