Self-organization of monodentate organic molecules on a solid surface — A Monte Carlo and transfer-matrix study

A lattice gas model of monodentate organic molecules on a solid surface in terms of pair directional interactions has been developed. As a special case of the constructed model the self-organization of CaTBPP on Au(111) surface was studied with Monte Carlo and transfer-matrix methods in the grand canonical ensemble. It is shown that the adsorbed molecules tend to form dimers when the hydrogen bonding between the molecules is relatively strong. Phase behavior of the system in this case can be characterized as the hierarchical self-assembly process. The self-assembly is led by the repulsive interactions between the building blocks those are the dimers of the adsorbate molecules stabilized with the strong hydrogen bonding. When hydrogen bonding is weak, a cross-like structure appears at moderate surface coverages. [Display omitted] •A novel lattice gas model with pair directional interactions has been developed.•When the hydrogen bonding is strong, the adsorbed molecules tend to form dimers.•Phase behavior of the system is characterized as the hierarchical self-assembly.•Phase behavior of the model in special case is similar to the dimer adsorption model.•When hydrogen bonding is weak, a cross-like structure appears at moderate coverages.