Controlling the growth of multiple ordered heteromolecular phases by utilizing intermolecular repulsion

Abstract

Metal/organic interfaces and their structural, electronic, spintronic and thermodynamic properties have been investigated intensively, aiming to improve and develop future electronic devices. In this context, heteromolecular phases add new design opportunities simply by combining different molecules. However, controlling the desired phases in such complex systems is a challenging task. Here, we report an effective way of steering the growth of a bimolecular system composed of adsorbate species with opposite intermolecular interactions-repulsive and attractive, respectively. The repulsive species forms a two-dimensional lattice gas, the density of which controls which crystalline phases are stable. Critical gas phase densities determine the constant-area phase diagram that describes our experimental observations, including eutectic regions with three coexisting phases. We anticipate the general validity of this type of phase diagram for binary systems containing two-dimensional gas phases, and also show that the density of the gas phase allows engineering of the interface structure.

Multishell Hollow Metal/Nitrogen/Carbon Dodecahedrons with Precisely Controlled Architectures and Synergistically Enhanced Catalytic Properties

“…Rational design and controllable fabrication of multilevel nanoarchitecture materials have long been considered as a research hot spot in the evolution of nanoscience and nanotechnology. − As a fascinating category of nanoarchitecture materials, hollow nanostructures have always gained a lot of attention due to their attractive properties such as large void volume, low density, and high surface-to-volume ratio, which endow them with various potential applications in solar cell, drug delivery, energy storage/conversion, and catalysis. − In particular, extensive efforts have been devoted to the construction of hollow nanomaterials with multiple shells to imbue the structure with increased large surface areas, multiphase heterogeneous interfaces, improved mass diffusion properties, excellent loading capacity, and thus, more elaborate functionalities. − Furthermore, these multishell hollow systems can also take advantage of the synergistic effects deriving from the interaction of different layers to modify their characteristics for a specific application and the confined environment to improve the mechanical and hydrothermal stability.…”

Interface Properties of CoPc on Nanographene-Covered Au(111) and the Influence of Annealing

“…Often bimolecular layers form ordered structures due to molecule–molecule interaction by H-bonds, dipole–dipole interaction or metal coordination. − In Figure , it seems that molecules of the same type (CoPc or HBC) tend to form domains, but also, a large number of single molecules and irregular spaces between the molecules (dark areas) are visible. Consequently, we could not identify a preferred ordering as discussed for CoPc and HBC MLs on Au(111) (cf.…”

Binding and Electronic Level Alignment of $\boldsymbolπ$-Conjugated Systems on Metals

“…With more elaborate versions such as LEED I-V, mentioned above, and spot-profile analysis LEED (SPA-LEED) a precise description of the adsorbate unit cell can be achieved 323 . Finally, low-energy electron microscopy (LEEM) provides in particular real-time information of the in-plane arrangement and morphology during growth 156,324,325 .…”

“…Most studies in the area are dealing with bimolecular mixed layers 71,175,325,576 , whereas only a few studies focus on bilayers 118,383,577-579 . For both types of heterostructures CuPc and PTCDA on Ag(111) have become popular 71,325,345,383,[578][579][580][581][582] . Figure 25a shows the experimentally determined adsorption geometries of PTCDA and CuPc in their respective monolayers on Ag(111) and in the bimolecular mixed layer 71 .…”