Molecular Self-Assembly on Two-Dimensional Atomic Crystals: Insights from Molecular Dynamics Simulations

Abstract

van der Waals (vdW) epitaxy of ultrathin organic films on two-dimensional (2D) atomic crystals has become a sovereign area because of their unique advantages in organic electronic devices. However, the dynamic mechanism of the self-assembly remains elusive. Here, we visualize the nanoscale self-assembly of organic molecules on graphene and boron nitride monolayer from a disordered state to a 2D lattice via molecular dynamics simulation for the first time. It is revealed that the assembly toward 2D ordered structures is essentially the minimization of the molecule-molecule interaction, that is, the vdW interaction in nonpolar systems and the vdW and Coulomb interactions in polar systems that are the decisive factors for the formation of the 2D ordering. The role of the substrate is mainly governing the array orientation of the adsorbates. The mechanisms unveiled here are generally applicable to a broad class of organic thin films via vdW epitaxy.

Dichotomous On-Surface Self-Assembly of Tripod Molecules with Anchor Like Interaction Pattern

“…An alternative approach which enables facile optimization of molecular systems on surfaces are the computer simulations [9,11,[24][25][26][27][28][29][30][31]. This technique is particularly useful, as it makes it possible to study readily the effect of intrinsic molecular properties on the corresponding superstructures formed under variable conditions (e.g.…”

Chirality-Selective Transport of Benzene Molecules on Carbon Nanotubes

“…According to the experimental observation of orientation-dependent interactions between CNTs and graphene, [25] the dependence of the molecular transport of CNTs on their chirality should be strongly correlated with the registry configuration of π orbitals at the interface as we are going to explain in details below. [26][27][28] Note that φ = 19.1 • is a so-called "magic" chiral angle of CNT, at which a structural transition may occur at the CNT interface. [29] FIG.…”

Observing the three-dimensional terephthalic acid supramolecular growth mechanism on a stearic acid buffer layer by molecular simulation methods

“…6 Since 2D supramolecules are mainly formed by the ordered arrangement of compositional molecules on the substrate, two key factors in constructing such a 2D supramolecule with specic textures are the relative orientations of the compositional molecules as well as the molecule's orientation to the substrate. 7 Consequently, understanding at the atomic scale how compositional molecules arrange themselves on the substrate is key to developing new 2D supramolecules. An analysis of the ordered pattern of compositional molecular arrangements observed by scanning tunneling microscopy (STM) 8,9 indicates that these compositional molecules are stabilized by the intermolecular hydrogen bonds and van der Waals force.…”