Raman spectroscopy as a tool to investigate the structure and electronic properties of carbon-atom wires

• Alberto Milani,
• Matteo Tommasini,
• Valeria Russo,
• Andrea Li Bassi,
• Andrea Lucotti,
• Franco Cataldo and
• Carlo S. Casari

Beilstein J. Nanotechnol. 2015, 6, 480–491, doi:10.3762/bjnano.6.49

• also attracted interest as a molecular junction, as shown in a number of theoretical investigations and a few experimental works regarding wires connected to graphene and nanotubes. These have shown interesting electronic and transport properties [80][81][82][83][84]. While experimental work is still

High speed e-beam lithography for gold nanoarray fabrication and use in nanotechnology

• Jorge Trasobares,
• François Vaurette,
• Marc François,
• Hans Romijn,
• Jean-Louis Codron,
• Dominique Vuillaume,
• Didier Théron and
• Nicolas Clément

Beilstein J. Nanotechnol. 2014, 5, 1918–1925, doi:10.3762/bjnano.5.202

• . In order to study more functional molecular junction (for example redox molecules), we need few mm-large gold nanoarray for chemical characterization with usual techniques such XPS. This requires high-speed e-beam lithography. We first describe the relevant e-beam operation mechanisms (Figure 1a

Strong spin-filtering and spin-valve effects in a molecular V–C₆₀–V contact

• Mohammad Koleini and
• Mads Brandbyge

Beilstein J. Nanotechnol. 2012, 3, 589–596, doi:10.3762/bjnano.3.69

• transport properties of a C60-molecular junction in a setup relevant for STM experiments. Our results demonstrate how the FM and AFM configurations can be identified due to their markedly different conductance and shot noise. Thus, it may allow for the study of the magnetic coupling between tip and

Transmission eigenvalue distributions in highly conductive molecular junctions

• Justin P. Bergfield,
• Joshua D. Barr and
• Charles A. Stafford

Beilstein J. Nanotechnol. 2012, 3, 40–51, doi:10.3762/bjnano.3.5

• molecular junction is formed, the energy levels of the molecule are broadened and shifted as a result of the formation of a lead–molecule bond and due to the electrostatic influence of the leads. The bonding between lead α and the molecule is described by the tunneling width matrix Γα and the electrostatics

• , including intramolecular screening and van der Waals effects, are described by the effective molecular Hamiltonian derived using the aforementioned π-EFT. Although we use the Pt–benzene–Pt junction as an example here, the techniques we discuss are applicable to any conjugated organic molecular junction

When “small” terms matter: Coupled interference features in the transport properties of cross-conjugated molecules

• Gemma C. Solomon,
• Justin P. Bergfield,
• Charles A. Stafford and
• Mark A. Ratner

Beilstein J. Nanotechnol. 2011, 2, 862–871, doi:10.3762/bjnano.2.95

• . Many-body calculations The many-body problem of transport through a molecular junction is generally intractable and must be solved approximately. Often this is done perturbatively by using, for example, diagrammatic methods. Phrasing the perturbative series in terms of Green’s functions is advantageous

• subject for investigation. Here we use Hückel, gDFTB and a many-body MDE theory to calculate the transport through each molecular junction and to determine the effects of topology, through-space coupling and interactions beyond the mean-field. The molecules considered In this paper we study a series of

Towards quantitative accuracy in first-principles transport calculations: The GW method applied to alkane/gold junctions

• Mikkel Strange and
• Kristian S. Thygesen

Beilstein J. Nanotechnol. 2011, 2, 746–754, doi:10.3762/bjnano.2.82

• corresponding to double-zeta plus polarization (DZP) for the Au atoms and double-zeta (DZ) for the atoms of the molecules. We use rather diffuse basis functions with a confinement-energy shift of 0.01 eV. This ensures that the calculated work function of Au(111) and the Kohn–Sham energy levels of the molecular

• junction are within 0.1 eV of those obtained from accurate grid calculations [24]. The transmission function is obtained from the Meir–Wingreen transmission formula [57][58] The retarded Green’s function of the extended molecule is calculated from Here S, H0, and Vxc are the overlap matrix, Kohn–Sham

Charge transport in a zinc–porphyrin single-molecule junction

• Mickael L. Perrin,
• Christian A. Martin,
• Ferry Prins,
• Ahson J. Shaikh,
• Rienk Eelkema,
• Jan H. van Esch,
• Jan M. van Ruitenbeek,
• Herre S. J. van der Zant and
• Diana Dulić

Beilstein J. Nanotechnol. 2011, 2, 714–719, doi:10.3762/bjnano.2.77

• allows us to characterize the transport in a molecular junction in detail. This complex molecule can form different junction configurations, having an observable effect on the trace histograms and the current–voltage (I(V)) measurements. Both methods show that multiple, stable single-molecule junction

• contact (defined as d = 0), only conductance values below one quantum unit G0 = 2e2/h (the resistance of a single gold atom) are considered. The results are plotted as two-dimensional “trace histograms”, in which areas of high counts represent the most typical breaking behavior of the molecular junction

• sub-G0 regime. The observation of such plateaus in the breaking traces is commonly taken as a signature of the formation of a molecular junction [15][16][17]. Figure 2b shows that the plateaus can be horizontal or sloped. Some traces consist of a few plateaus at different conductance values. The

An MCBJ case study: The influence of π-conjugation on the single-molecule conductance at a solid/liquid interface

• Wenjing Hong,
• Hennie Valkenier,
• Gábor Mészáros,
• David Zsolt Manrique,
• Artem Mishchenko,
• Alexander Putz,
• Pavel Moreno García,
• Colin J. Lambert,
• Jan C. Hummelen and
• Thomas Wandlowski

Beilstein J. Nanotechnol. 2011, 2, 699–713, doi:10.3762/bjnano.2.76

• the molecular (-junction) conductance. However, due to the relative low conductance of broken-conjugated and cross-conjugated rigid rodlike molecules [26], reliable transport measurements through these types of molecular junctions are still a challenging topic. Charge-transport characteristics of

• technique provides a high mechanical stability [52] due to the short distance between the two free-standing electrode-tip ends and the support. In consequence, molecular junction stretching and formation processes can be controlled with high precision and stability on the time scale of seconds, even at room

• of a molecular junction. These data were chosen for distance calibration. The red curves in Figure 4 indicate the successful formation of gold|AC|gold molecular junctions with a characteristic plateau. The three representative individual traces reveal a single plateau conductance at around 10−4.5 G0