Surface Trapping of Atoms and Molecules with Dipole Rings

Abstract

The trapping of single molecules on surfaces without the formation of strong covalent bonds is a prerequisite for molecular recognition and the exploitation of molecular function. On nanopatterned surfaces, molecules may be selectively trapped and addressed. In a boron nitride nanomesh formed on Rh(111), the pattern consisted of holes 2 nanometers in diameter on a hexagonal superlattice, separated by about 3 nanometers. The trapping was further investigated with density functional theory and the photoemission of adsorbed xenon, where the holes were identified as regions of low work function. The analysis showed that the trapping potential was localized at the rims of the holes.

Hexagonal boron nitride on transition metal surfaces

“…The adsorbate is characterized by ''pores'' of about 2 nm diameter that strongly interact with the metal and elevated regions, where the interaction with the metal is weak, that form the connected ''wire'' network. The strong variation in bonding leads to a corresponding variation of the electrostatic potential above the monolayer that is responsible for trapping molecules [17]. The h-BN/ Rh(111) nanomesh is a very stable structure that withstands temperatures of 1,000 K and can be exposed to liquids without losing its properties.…”

Efficient gating of epitaxial boron nitride monolayers by substrate functionalization

“…This originates from the different reference substrates that are used in the two analyses, hBN/Sub and hBN/Sub. 1 Most interestingly, the above analysis shows that the hBN plane is within a capacitorlike linear potential profile along the z direction [ Fig. 4(a)].…”

“…First results on chemical functionalization of hBN have also been reported by trapping atoms or molecules on the dipole rings of epitaxial boron nitride [1]. The ionicity of the B-N bond induces a wide band gap in hBN with a direct optical transition for bulk hBN of about 5.9 eV [3,6,7].…”

“…Hexagonal boron nitride (hBN), a structural analog to graphene, has been attracting considerable research attention due to its outstanding mechanical properties, its potential for surface chemistry [1], and its potential applications in far-ultraviolet (far-UV) optoelectronic devices [2,3] and twodimensional (2D) heterostructures comprising graphene and hBN [4,5]. First results on chemical functionalization of hBN have also been reported by trapping atoms or molecules on the dipole rings of epitaxial boron nitride [1].…”

Guided Molecular Assembly on a Locally Reactive 2D Material

“…[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.…”