Ultrathin Organic Layers on Silicon Surfaces

Abstract

We discuss two inequivalent ways for describing magnetized D-branes wrapped N times on a torus T 2 . The first one is based on a non-abelian gauge bundle U(N ), while the second one is obtained by means of a Narain T-duality transformation acting on a theory with non-magnetized branes. We construct in both descriptions the boundary state and the open string vertices and show that they give rise to different string amplitudes. In particular, the description based on the gauge bundle has open string vertex operators with momentum dependent Chan-Paton factors.

Chemical manipulation of multifunctional hydrocarbons on silicon surfaces

“…It has been shown that styrene (Ph-CH=CH 2 ) and phenylacetylene (Ph-C≡CH) react with the Si(100)-2×1 surface by [2 + 2] cycloaddition. Despite the fact that there is a potential for the interaction of the vinyl group of styrene with the phenyl ring to form an alternative conjugated diene system to enable it to participate in a [4 + 2] process, styrene reacts predominantly by a [2 + 2] reaction between its vinyl group and the silicon dimer of the Si(100)-2×1 surface [216,220,221,223]. The STM studies presented in Fig.…”

Molecular simulation study of nanoscale friction for alkyl monolayers on Si(111)

“…7-10 Such organic thin films are also prepared by other methods, such as electrochemistry. [11][12][13] The new monolayer coating via Si-C linkage has several key advantages over the previously reported silane-based SAMs: 3 ͑i͒ The coating does not produce HCl; ͑ii͒ the coating does not require the formation of an intervening oxide layer; ͑iii͒ the film formation procedure is simpler; ͑iv͒ the coating process is much more robust; ͑v͒ the coated surface has much fewer particulates; and ͑vi͒ the film is stable up to 615 K. 7 The direct reaction between alcohols and H-terminated 14 or Cl-terminated 15,16 silicon surfaces has also been proposed to form stable organic films via Si-O linkage. Further modification of these stable monolayers can be performed for other applications, such as biosensors and lab-on-chips.…”

Molecular Assembly and Self‐Assemblya: Molecular Nanoscience for Future Technologies

“…On semiconductor substrates, the strong and directed covalent bonds between the adsorbate and the adsorbent atoms often inhibit the growth of periodic and defect free layers. There, molecules have been imaged and show interesting characteristics that, for example, allow the identification of molecular orientation and bonding 21–23. In the case of metal substrates with lower reactivity, such as the noble metals Au and Ag, or Cu, the diffusiveness of the molecule on the substrate allows the observation and analysis of quite different phenomena: the molecules “feel” the corrugation of the substrate, and the lateral random‐walk diffusion of a single adsorbate is determined by the corrugation of the potential energy surface (surface potential) of the adsorbate‐substrate complex and by the kinetic energy available for hopping between stable adsorption sites.…”

“…There, molecules have been imaged and show interesting characteristics that, for example, allow the identification of molecular orientation and bonding. [21][22][23] In the case of metal substrates with lower reactivity, such as the noble metals Au and Ag, or Cu, the diffusiveness of the molecule on the substrate allows the observation and analysis of quite different phenomena: the molecules "feel" the corrugation of the substrate, and the lateral random-walk diffusion of a single adsorbate is determined by the corrugation of the potential energy surface (surface potential) of the adsorbate-substrate complex and by the kinetic energy available for hopping between stable adsorption sites. For Cu-TBPP adsorption on Ag(110) a complex adsorption behavior with fast diffusing precursor and slowly moving final adsorption states has been observed.…”