Large Molecule Epitaxy on Single Crystal Metals, Insulators and Single Crystal and MBE-Grown Layered Semiconductors

Abstract

We review the packing structures for a series of aromatic hydrocarbons, deposited by vacuum deposition methods as ordered monolayers→→multilayers, on a variety of metal, semiconductor and insulator surfaces. New results are presented for the adsorption of monolayers of perylenes, phthalocyanines, coronene, and pentacenes on the Cu(100) surface, along with the implications of these studies for the formation of ordered multilayers of these molecular systems. Aromatic molecules without heteroatoms appear to pack in a flat-lying motif, and exhibit approximately hexagonal close packing, even on a substrate with four-fold symmetry such as Cu(100). In general, aromatic systems whose bulk structures lend themselves to layer-by-layer growth during vacuum deposition appear to be the best candidates for ordered multilayer growth.

3D island growth of 6,13 Pentacenequinone on silicon oxide and gold

“…After the deposition of this layer, in which the PQ molecules are supposed to lie flat according to Refs. [28][29][30], the PQ growth on gold follows the same qualitative evolution as in the case of silicon oxide. Even though the growth (initial wetting layer, compact islands and needle-like islands) is quite similar for both surfaces, we note that the substrate influences the dynamics: the substrate mainly contributes to the arrangement of the initial wetting layer, but also influences the degree of order of the growth and the dimensions of grains.…”

Selective adsorption of coronene on Si(111)-(7×7)

“…However, the molecular arrangement is mainly driven by minimization of van der Waals intermolecular forces, resulting in densely packed layers. The hexagonal shape of the molecule favors the formation of hexagonal lattices [4,5,6], even when the substrate has fourfold symmetry such as Cu(100) [7] or twofold symmetry such as Cu(110) [8] or Ag(110) [9]. This is a clear indication that on metal surfaces, the intermolecular forces play the most important role in stabilizing the molecular networks, also favored by the considerable freedom that the molecules have to diffuse on surfaces with a laterally homogeneous density of electronic states.…”

Decoupling-free NMR quantum computer on a quantum spin chain

“…Moreover, one could utilize a well-established chemical technique of the selective isotope replacement of 1 H by 2 D (I = 1) [49] or 12 C (I = 0) by 13 C (I = 1/2). The periodic placements of the qubits may be achieved with the epitaxial growth [50] and/or the Langmuir-Blodgett methods as follows. One prepares two sets of molecules with the same chemical formulas but different isotopes by the selective isotope replacement technique, for example, all deuterized samples and those having 1 H's at one of the hydrogen sites.…”