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O: Fachverband Oberflächenphysik
O 8: Poster Session I: Solid-liquid interfaces: Structure, spectroscopy
O 8.2: Poster
Montag, 1. März 2021, 10:30–12:30, P
bias- and concentration- dependent switching of supramolecular nanostructures at the solid-liquid interface — •Baoxin Jia1, Mihaela Enache1, Sandra Miguez-Lago2, Milan Kivala2, and Meike Stöhr1 — 1Zernike Institute for Advanced Materials, University of Groningen, Netherlands — 2Institute of Organic Chemistry, University of Heidelberg, Germany
Research into the controlled switching between different molecular phases at the solid-liquid interface induced by an external trigger has gained increasing attention over the past years, also in view of application as smart surfaces. Here we discuss the bias- and concentration-dependent switching of a carboxy-functionalized triarylamine derivative at the HOPG/nonanoic interface studied by scanning tunneling microscopy. For a fully saturated solution, a porous phase (chickenwire) was observed for negative sample bias and a close-packed phase was observed for positive sample bias. For a 50% saturated solution, a second porous phase (flower) coexisted with the chickenwire phase at negative sample bias, while the close-packed phase was still observed at positive sample bias. For a 20% saturated solution, the two porous phases and the close-packed phase coexisted at positive sample bias because of the low molecule concentration in the solution. By changing the sample bias from negative to positive, an electric field-induced phase transition from the porous phases to the close-packed phase was accomplished, which was fully reversible by changing the bias back. Our study demonstrates that switching can be accomplished by changing the polarity of the applied external electric field.