Molecular Epitaxy on Two-Dimensional Materials: The Interplay between Interactions

Abstract

Molecular epitaxythe process of growing a crystalline overlayer onto a substrateat the two-dimensional (2D) material interfaces, opens new avenues toward the integration of 2D materials with a large variety of functional molecules. The emerging field of controlling molecular epitaxy on 2D materials interfaces toward functional heterostructures and novel optoelectronic devices clearly requires the understanding of the interplay between molecular interactions at the interfaces. In this article, we review the mechanisms governing molecular epitaxy on 2D materials, with an emphasis on the diverse interactions involved, including (i) the intermolecular interactions between the deposited molecules, (ii) the molecule–2D material interactions, and (iii) the molecule–substrate interactions through the 2D material. The interplay between these interactions determines the dimension, interfacial orientation, crystal packing, morphology, and electronic properties of the epitaxial layer. We further review the state-of-art applications, which might benefit from tailoring molecular interactions at 2D materials interfaces.

Synthesis and Two‐Dimensional Chiral Surface Self‐Assembly of a π‐Conjugated System with Three‐Fold Symmetry: Benzotri(7‐Azaindole)

“…Differently from the studies in solution and in crystal engineering, self‐assembly on surfaces is governed by the subtle balance between molecule‐molecule interactions and molecule‐substrate interactions. As expected, considering that the interactions with the substrate surface are mainly established through van der Waals forces, [3] the physical and chemical properties of the substrate can condition the growth of the physisorbed adlayer. Moreover, the structure of the self‐assembled material will depend on the molecular design and the type of non‐covalent interactions controlling the self‐assembly.…”

Patterning 2D Organic Crystalline Semiconductors via Thermally Induced Self‐Assembly

“…Other organic materials, e.g., copper phthalocyanine and para‐sexiphenyl, can also exhibit similar growth behavior. [ 56 ] At even higher temperature of 125 °C, the molecules in each layer became thermodynamically unstable and reassembled (Figure 3e). Therefore, the annealing temperature‐mediated interfacial interactions between the molecules and substrate can trigger controlled formation of layer‐controllable ultrathin molecular semiconductor film arrays.…”

Synthesis and Two‐Dimensional Chiral Surface Self‐Assembly of a π‐Conjugated System with Three‐Fold Symmetry: Benzotri(7‐Azaindole)

“…[1] Self-assembly through non-covalent interactions provides the tools for abottom-up strategy to obtain well-ordered 2D supramolecular architectures. [2] Differently from the studies in solution and in crystal engineering,s elf-assembly on surfaces is governed by the subtle balance between molecule-molecule interactions and molecule-substrate interactions.A se xpected, considering that the interactions with the substrate surface are mainly established through van der Waals forces, [3] the physical and chemical properties of the substrate can condition the growth of the physisorbed adlayer. Moreover,t he structure of the self-assembled material will depend on the molecular design and the type of non-covalent interactions controlling the selfassembly.Among the different interactions studied in 2D selfassembled materials,h ydrogen bonding is particularly useful due to its strength, directionality and variety of functions that can work as hydrogen bond donor or acceptor sites.…”