Understanding Periodic Dislocations in 2D Supramolecular Crystals: The PFP/Ag(111) Interface.
In-plane dislocation networks arise in both inorganic and organic films as a way of relieving the elastic strain that builds up at the substrate interface. In molecule/surface systems, supramolecular interactions are weak and more complex (compared to the atomic bonds in inorganic films), and their interplay with molecule-substrate interactions is very subtle, making it difficult to single out the driving force for a nanoscale dislocation pattern. On the basis of a combined experimental and theoretical work, we here show that periodic dislocations in a molecular PFP film are mainly driven by the optimization of molecule-substrate interactions. Compared to inorganic networks however, it implies a much lower energy imbalance, allowing a thermally induced transition from a low-energy strain dislocation pattern to a high-energy incommensurate moiré.
†Donostia International Physics Center, Paseo Manuel Lardizabal 4, E-20018 Donostia-San Sebastián, Spain.
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Goiri
‡Department of Physics, Technical University of Denmark, DK-2800 Copenhagen, Denmark.
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García-Lastra
†Donostia International Physics Center, Paseo Manuel Lardizabal 4, E-20018 Donostia-San Sebastián, Spain.
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Corso
¶Centro de Física de Materiales CSIC/UPV-EHU-Materials Physics Center, E-20018 Donostia-San Sebastián, Spain.
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Adb El-Fattah
†Donostia International Physics Center, Paseo Manuel Lardizabal 4, E-20018 Donostia-San Sebastián, Spain.|¶Centro de Física de Materiales CSIC/UPV-EHU-Materials Physics Center, E-20018 Donostia-San Sebastián, Spain.|∥Dpto. de Física Aplicada I, Universidad del País Vasco, E-20018 Donostia-San Sebastián, Spain.
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Ortega
¶Centro de Física de Materiales CSIC/UPV-EHU-Materials Physics Center, E-20018 Donostia-San Sebastián, Spain.|§Department of Physics, University of California at Berkeley, Berkeley, California 94720, United States.
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de Oteyza
epitaxy; moiré; organic; perfluoropentacene; strain; template