Imprinting Br-atoms at Si(111) from a SAM of CH3Br(ad), with pattern retention

Dobrin, Sergey; Lu, Xuekun; Naumkin, Fedor Y.; Polanyi, J. C.; Yang, Jun

doi:10.1016/j.susc.2004.09.048

Cited by 29 publications

(57 citation statements)

References 29 publications

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“…Previously we demonstrated MSI employing halogenated alkanes at a Sið111Þ-7×7 surface. There we were able to self-assemble physisorbed circles of 12 methyl bromide (11) or propyl bromide molecules (12) at approximately 50 K and chemically imprint them using ultraviolet light to produce chemisorbed circles of 12 brominated silicon atoms. Subsequently we found a means to the linear propagation of physisorbed organic halide (dichloropentane) on Sið100Þ-2×1.…”

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confidence: 99%

Imprinting self-assembled patterns of lines at a semiconductor surface, using heat, light, or electrons

Harikumar

McNab²,

Polanyi³

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

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The fabrication of nano devices at surfaces makes conflicting demands of mobility for self-assembly (SA) and immobility for permanence. The solution proposed in earlier work from this laboratory involved pattern formation in physisorbed molecules by SA, followed by localized reaction to chemically imprint the pattern substantially unchanged, a procedure we termed molecular-scale imprinting (MSI). Here, as proof of generality we extended this procedure, previously applied to imprinting circles on Si(111)-7 × 7, to SA lines of 1-chloropentane (CP) on Si(100)-2 × 1. The physisorbed lines consisted of pairs of CP that grew perpendicular to the Si dimer rows, as shown by scanning tunneling microscopy and ab initio theory. Chemical reaction of these lines with the surface was triggered in separate experiments by three different modes of energization: heat, electrons, or light. In all cases the CP molecules underwent MSI with a Si atom beneath so that the physisorbed lines of CP pairs were imprinted as chemisorbed lines of Cl pairs.

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confidence: 99%

Imprinting self-assembled patterns of lines at a semiconductor surface, using heat, light, or electrons

Harikumar

McNab²,

Polanyi³

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

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“…On the surface of the semiconductor GaAs the mechanism leading to dissociation could be tuned through the appropriate doping [19,20]. Finally, scanning tunnelling micrographs of the bromine atoms remaining on the surface after photodissociation have been obtained on a silicon surface [21].…”

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Femtosecond‐laser photoemission and photodesorption from magnesia supported gold clusters

Vaida

Gleitsmann

Tchitnga

et al. 2010

Physica Status Solidi (b)

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Nanosize gold clusters were grown by thermal evaporation on ultrathin magnesia films on Mo(100) and investigated by femtosecond (fs)-laser photoemission spectroscopy. The surface work function in this system was found to increase with increasing nominal gold coverage. Methyl bromide (CH 3 Br) molecules adsorb molecularly on the magnesia surface as well as on the gold clusters. At sub-monolayer coverage the CH 3 Br molecules were, however, considerably stronger bound to the gold particles than to the magnesia surface as revealed by temperature programmed desorption spectroscopy. To investigate the photoreaction dynamics of the adsorbate molecules fs-laser pump-probe mass spectrometry was applied. In this new approach the methyl fragment appearance was monitored after photoexcitation of the adsorbed CH 3 Br with fs time resolution. The transient methyl data revealed that the CH 3 Br dissociation and subsequent methyl desorption proceeded in less than one picosecond. Most interestingly, a part of the transient signal could be unambiguously assigned to the dynamics of methyl desorption from the gold clusters. The appearance of this signal at about 270 fs after photoexcitation illustrates the massive distortion of the CH 3 Br electronic level structure due to the strong interaction with the gold clusters compared to the bare magnesia surface.

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“…Because of the difficulties outlined directly above, alternate attachment strategies have been explored for patterning molecular layers on 7 × 7 in vacuo 21–23. These have included: the photon and electron‐induced covalent attachment of patterned physisorbed layers at 50 K 21 and the chiral modification of 7 × 7 half cells by the adsorption of π‐conjugated zwitterionic molecules 22, 23. Notwithstanding the success of these approaches, templating organic layers using 7 × 7, with the quality of cyclopentene/Si(100), still presents a significant challenge to our understanding of both interface formation on 7 × 7 and the surface chemistry of the 7 × 7 reconstruction.…”

Section: Templating Strategiesmentioning

confidence: 99%

Using steric constraints to template an organic array on Si(111)‐7 × 7

McLean

Weymouth

Edge

et al. 2012

Physica Status Solidi (a)

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We show that the Si(111)‐7 × 7 surface reconstruction can be used to template an ordered array of 1,3,5‐trimethyl benzene (mesitylene) molecules. The disorder that normally derives from the multiplicity of admissible adsorption geometries, for small aromatic molecules on 7 × 7, is suppressed, and the molecules are found to occupy both halves of the 7 × 7 unit cell with equal probability. It is argued that a steric interaction, associated with the methyl groups, hinders nearest neighbor adsorption and this leads to the formation of an array that has the molecules at the corners of the 7 × 7 half unit cells. To understand the ordering kinetics we used: scanning tunneling microscopy to study site occupancy as a function of coverage, ab initio total energy calculation to study the stability of the attachment sites and kinetic Monte Carlo modeling to investigate the emergence of translational order in the overlayer. When two mesitylene molecules adsorb in nearest neighbor bridging geometries on the 7 × 7 reconstruction, the hydrogen atoms located on the methyl groups interact. To reduce the interaction energy, the molecules form an ordered array that places each molecule at the corner of the half cell.

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Imprinting Br-atoms at Si(111) from a SAM of CH3Br(ad), with pattern retention

Cited by 29 publications

References 29 publications

Imprinting self-assembled patterns of lines at a semiconductor surface, using heat, light, or electrons

Imprinting self-assembled patterns of lines at a semiconductor surface, using heat, light, or electrons

Femtosecond‐laser photoemission and photodesorption from magnesia supported gold clusters

Using steric constraints to template an organic array on Si(111)‐7 × 7

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