Guided Molecular Assembly on a Locally Reactive 2D Material

Abstract

occurs when 2D materials are placed on a substrate, such as when they are epitaxially grown upon a metallic surface. [11,12] For example, it has been shown that molecules can become trapped within nanopores of hexagonal boron nitride grown on Ru (0001) because of dipolar interactions; [13,14] similar results have also been observed for nanopores on the surface of bulk SiC. [15] Physisorption of a molecule to a surface (i.e., van der Waals bonding) is often not strong enough to fix the molecule's position at room temperature, particularly on the surface of bulk metal crystals. This is more readily accomplished by anchoring the mole cule to the surface through chemisorption of part of the molecule to the surface. [16][17][18] However, care must be taken to limit hybridization that can cause detrimental modifications of the molecule and its frontier orbitals, [19,20] especially on different surface reconstructions of bulk semiconductors like silicon. [15,17] It is therefore of interest to investigate the interface between molecules and more reactive 2D materials in an attempt to isolate individual molecules at room temperature while retaining their localized electronic states.With its mixed sp 2 -sp 3 character, silicene-the silicon analogue of graphene-has the potential to provide unique properties for molecular templating. This is particularly true because the structural and electronic properties of silicene are more susceptible to modification [21][22][23][24][25][26] once it is formed upon a surface, owing to its greater reactivity than graphene and the flexibility of The interactions between atomic or molecular adsorbates and the surfaces of 2D materials are of interest for applications ranging from catalysis [1] and molecular sensing [2] to molecular electronics and spintronics. [3][4][5] For the prototypical 2D material graphene, there are typically only weak van der Waals interactions between molecules and the surface. [6] This allows for the fabrication of functional self-assembled monolayers [6][7][8] that are reminiscent of the ordered supramolecular arrangements that can be formed on the surfaces of bulk (3D) materials. [9] However, isolating individual molecules is more challenging. [10] In contrast, new possibilities for templating emerge from nanostructuring that

Adatom-induced dislocation annihilation in epitaxial silicene

“…As shown in figure 1(c), epitaxial silicene crystallizes in the domains in the planar-like structure in which five out of the six Si The repulsion between domain boundaries through the stress field they generate [28], induces the organization of the dislocations into a periodical array. As seen in figure 1(c), the partial dislocations are 3 √ 3a ZrB2 /2-wide (where a ZrB2 = 3.18 Å is the lattice parameter of the ZrB 2 (0001)) and are of two different types, symmetric with respect to each other in a mirror symmetry operation and perfectly alternated along the direction perpendicular to the stripe domains [29,30]. Their respective Burgers vectors are…”

“…As a consequence, the resolution of the protrusions in STM images and the observation of the shift direction between neighboring domains allow for determining the positions of all Si atoms in the silicene sheet. Note that owing to different local densities of states in the domains and in the boundaries [30], the stripe domain structures can be easily visualized by choosing a proper bias voltage, even in large scale images such as the one in figure 1(a).…”

Functionalization of group-14 two-dimensional materials

“…For example, phthalocyanine (H 2 Pc) was predicted to interact weakly with silicene/Ag(1 1 1) system [197]. Its family member, iron phthalocyanine (FePc) has been deposited on silicene/ZrB 2 and was shown to remain stable up to room temperature at the same time retaining its electronic states [198]. Nitrophenyl diazonium (NPD) on silicene is another example of functionalized system in which each NPD functional group is doped by 0.65 e, and exhibits spinpolarized ferrimagnetism [199].…”

Study on Formation Process and Models of Linear Fe Cluster Structure on a Si(111)-7 × 7-CH3OH Surface

“…Accordingly, thin film materials are given high expectations, such as the regular structure of metal clusters and the high-density of memory units [ 3 , 4 , 5 ]. In recent years, atomic level technologies have increased the interest of researchers [ 6 ]. As the important substrate material, Si(111)-7 × 7 is a surface with well-established atomic and electronic structures [ 7 , 8 ].…”