# N,N&#x27;-dimethylperylene-3,4,9,10-bisdicarboximide on alkali halide001 surfaces - Condensed Matter > Materials Science

Abstract: The growth of N,N-dimethylperylene-3,4,9,10-bisdicarboximide DiMe-PTCDIon KBr001 and NaCl001 surfaces has been studied. Experimental results havebeen achieved using frequency modulation atomic force microscopy at roomtemperature under ultra-high vacuum conditions. On both substrates, DiMe-PTCDIforms molecular wires with a width of 10 nm, typically, and a length of up to600 nm at low coverages. All wires grow along the 110 direction or1$\bar{1}$0 direction, respectively of the alkali halide 001 substrates.There is no wetting layer of molecules: Atomic resolution of the substrates canbe achieved between the wires. The wires are mobile on KBr surface butsubstantially more stable on NaCl. A p2 x 2 superstructure in brickwallarrangement on the ionic crystal surfaces is proposed based on electrostaticconsiderations. Calculations and Monte-Carlo simulations using empiricalpotentials reveal possible growth mechanisms for molecules within the firstlayer for both substrates, also showing a significantly higher binding energyfor NaCl001. For KBr, the p2 x 2 superstructure is confirmed by thesimulations, for NaCl, a less dense, incommensurate superstructure ispredicted.

Author: Markus Fendrich, Manfred Lange, Christian Weiss, Tobias Kunstmann, Rolf Moeller

Source: https://arxiv.org/