Tailoring molecular island shapes: influence of microscopic interaction on mesostructure

• Published in: Nano research Vol. 13; no. 3; pp. 843 - 852
• Main Authors: Aeschlimann, Simon, Lyu, Lu, Stadtmüller, Benjamin, Aeschlimann, Martin, Kühnle, Angelika
• Format: Journal Article
• Language: English
• Published: Beijing Tsinghua University Press 01.03.2020; Springer Nature B.V
• Subjects: Approximation; Atomic/Molecular Structure and Spectra; Biomedicine; Biotechnology; Calcium fluoride; Chemistry and Materials Science; Condensed Matter Physics; Copper; Design; Electronic structure; Fabrication; Gold; Image resolution; Islands; Lattice parameters; Materials Science; Microscopy; Molecular structure; Nanotechnology; Physical chemistry; Research Article; Scanning probe microscopy; Self-assembly; Substrates; Symmetry; Tuning; self-assembly; two-dimensional structures; island shape; mesostructure; scanning tunneling microscopy (STM); scanning probe microscopy (SPM)
• ISSN: 1998-0124; 1998-0000
• DOI: 10.1007/s12274-020-2705-0

Controlling the structure formation of molecules on surfaces is fundamental for creating molecular nanostructures with tailored properties and functionalities and relies on tuning the subtle balance between intermolecular and molecule-surface interactions. So far, however, reliable rules of design are largely lacking, preventing the controlled fabrication of self-assembled functional structures on surfaces. In addition, while so far many studies focused on varying the molecular building blocks, the impact of systematically adjusting the underlying substrate has been less frequently addressed. Here, we elucidate the potential of tailoring the mesoscopic island shape by tuning the interactions at the molecular level. As a model system, we have selected the molecule dimolybdenum tetraacetate on three prototypical surfaces, Cu(111), Au(111) and CaF 2 (111). While providing the same hexagonal geometry, compared to Cu(111), the lattice constants of Au(111) and CaF 2 (111) differ by a factor of 1.1 and 1.5, respectively. Our high-resolution scanning probe microscopy images reveal molecular-level information on the resulting islands and elucidate the molecular-level design principles for the observed mesoscopic island shapes. Our study demonstrates the capability to tailor the mesoscopic island shape by exclusively tuning the substrate lattice constant, in spite of the very different electronic structure of the substrates involved. This work provides insights for developing general design strategies for controlling molecular mesostructures on surfaces.