Dipole-directed assembly of lines of 1,5-dichloropentane on silicon substrates by displacement of surface charge

Harikumar, K. R.; Lim, Tingbin; McNab, I.R.; Polanyi, J. C.; Zotti, Linda A.; Ayissi, Serge; Hofer, Werner A.

doi:10.1038/nnano.2008.65

Cited by 58 publications

(47 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Surface buckling similar to the features marked "b" in Fig 1 was previously observed for 1,5-dichloropentane and also for pairs of 1-fluoropentane molecules (13,14). Exhaustive calculations showed that the buckling arose because of the asymmetry of these molecular pairs, which caused a buildup of charge and hence brightness at a silicon dimer located to one side of the adsorption site (13,14).…”

Section: Resultssupporting

confidence: 76%

“…The adsorption product that we image by STM consists, however, of stable CP pairs. In previous work (13,14) such stabilization of pairs was shown by theory to be due to charge-transfer in the surface. The rate of CP pair formation and subsequent line formation depends quadratically on the concentration of mobile CP (ad), whereas the competing rate of desorption back to the gas phase depends linearly on this quantity.…”

Section: Resultsmentioning

confidence: 81%

“…Subsequently we found a means to the linear propagation of physisorbed organic halide (dichloropentane) on Sið100Þ-2×1. Linear self-assembly was found to be due to dipole-directed assembly (DDA) in which the displacement of surface charge, caused by an initial physisorption event, rendered an adjacent surface site attractive to subsequent physisorption (13). A further finding pertinent to the present study was the identification of "cooperative" surface reaction in which the first molecule of a physisorbed pair of halides (fluoropentane molecules) invariably triggered the reaction of the second molecule of the pair (14).…”

mentioning

confidence: 67%

“…Exhaustive calculations showed that the buckling arose because of the asymmetry of these molecular pairs, which caused a buildup of charge and hence brightness at a silicon dimer located to one side of the adsorption site (13,14). The surface buckling was shown to attract adsorbates and constitute the growing point for the line formation (13).…”

Section: Resultsmentioning

confidence: 99%

See 3 more Smart Citations

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.

Self Cite

View full text Add to dashboard Cite

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.

show abstract

Section: Resultssupporting

confidence: 76%

Section: Resultsmentioning

confidence: 81%

mentioning

confidence: 67%

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

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.

Self Cite

View full text Add to dashboard Cite

show abstract

“…In some cases, these interactions were shown to dominate over forces resulting from chemical bonds between the molecules. Various examples can be found in published studies of organics under ambient atmospheric conditions, 1 at the liquid-solid interface 2 and under ultrahigh vacuum conditions, [3][4][5][6][7][8] with the molecular dipole aligned perpendicular to the surface 9 or within the surface plane, 3,4 and for various molecule sizes ranging from small molecules such as quinonoid zwitterions 3 and styrenes 4 to larger ones such as anthracene. 10 In reviewing those reported assemblies of dipolar molecules, it becomes evident that most of them do a) Electronic mail: ezurek@buffalo.edu b) Electronic mail: aenders2@unl.edu not correspond to a configuration of lowest electrostatic energy.…”

Section: Introductionmentioning

confidence: 99%

Self-assembly of strongly dipolar molecules on metal surfaces

Kunkel

Hooper

Simpson

et al. 2015

The Journal of Chemical Physics

View full text Add to dashboard Cite

The role of dipole-dipole interactions in the self-assembly of dipolar organic molecules on surfaces is investigated. As a model system, strongly dipolar model molecules, p-benzoquinonemonoimine zwitterions (ZI) of type C 6 H 2 (· · · NHR) 2 (· · · O) 2 on crystalline coinage metal surfaces were investigated with scanning tunneling microscopy and first principles calculations. Depending on the substrate, the molecules assemble into small clusters, nano gratings, and stripes, as well as in two-dimensional islands. The alignment of the molecular dipoles in those assemblies only rarely assumes the lowest electrostatic energy configuration. Based on calculations of the electrostatic energy for various experimentally observed molecular arrangements and under consideration of computed dipole moments of adsorbed molecules, the electrostatic energy minimization is ruled out as the driving force in the self-assembly. The structures observed are mainly the result of a competition between chemical interactions and substrate effects. The substrate's role in the self-assembly is to (i) reduce and realign the molecular dipole through charge donation and back donation involving both the molecular HOMO and LUMO, (ii) dictate the epitaxial orientation of the adsorbates, specifically so on Cu(111), and (iii) inhibit attractive forces between neighboring chains in the system ZI/Cu(111), which results in regularly spaced molecular gratings. C 2015 AIP Publishing LLC. [http://dx

show abstract

Orientation Control of Selected Organic Semiconductor Crystals Achieved by Monolayer Graphene Templates

Zhang

Roy

Safron

et al. 2016

Adv Materials Inter

View full text Add to dashboard Cite

orientations in thin films. First of all, elucidating the effect of excited state delocalization, including singlet excitons, triplet excitons, and charge transfer states, on charge generation and recombination processes in crystalline thin films and molecular heterointerfaces requires controlled access to varied molecular orientations. A lying-down orientation provides larger out-of-plane exciton diffusion lengths and favorably increases the rate of energy transfer and charge generation and transport in molecular thin films but unfavorably increases recombination of Charge transfer (CT) states and free charges across a molecular heterointerface. [5][6][7][8] Second, the amount of total light absorbed by crystalline thin films can vary by orders of magnitude depending on the orientation of the molecular transition dipole moment relative to the electric field of incident light. [9,10] Third, the molecular orientation relative to the substrate primarily determines the energy band edge of the film. [11,12] Therefore, developing a universal platform to gain insight into the dependence of various OPV performance parameters on molecular orientations and establishing reliable and robust methods to control the molecular orientations in thin films is necessary.Aromatic molecules, with the notable exception of 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) mostly adopt a standing-up orientation on weakly interacting substrates, such as oxides, which are widely used in OPVs. A lyingdown molecular orientation in thin films can be achieved with thickness greater than tens of nanometers (beyond the typical thickness for OPV active layers) by quasi-epitaxial growth, in which a templating layer induces substrate-molecule interactions that are comparable to intermolecular interactions. [13] Several templating materials have been used, such as copper iodide (CuI), [14] MoS 2 , [15] alkali metal halide, [16] PTCDA, [17][18][19] and graphene. [4,13,20] Graphene is a promising template for OPVs due to its high transparency and electrical conductivity, and its ability to be transferred onto arbitrary substrates as compared to other templating materials. [21] However, thus far, only thin films of phthalocyanine and acene molecules have been templated with graphene. [4,21] A broader study of molecular-level orientation control in various technologically relevant organic Crystal orientation in organic thin films is one of the key parameters that determine absorption cross-section, interfacial energetics and excitonic states, and free charge properties. In this work, monolayer graphene is used to direct the crystal orientation of selected planar organic molecules. Lyingdown orientation with π-stacking normal to the surface is achieved with graphene templating. The absorption spectra of the graphene-templated films are correlated to molecular orientation. The same set of absorption features with or without graphene suggests that no vibronic states are forbidden or newly introduced. However, the light absorption with graphene templati...

show abstract

Dipole-directed assembly of lines of 1,5-dichloropentane on silicon substrates by displacement of surface charge

Cited by 58 publications

References 56 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

Self-assembly of strongly dipolar molecules on metal surfaces

Orientation Control of Selected Organic Semiconductor Crystals Achieved by Monolayer Graphene Templates

Contact Info

Product

Resources

About