Molecular attachment to a microscope tip: inelastic tunneling, Kondo screening, and thermopower

• Rouzhaji Tuerhong,
• Mauro Boero and
• Jean-Pierre Bucher

Beilstein J. Nanotechnol. 2019, 10, 1243–1250, doi:10.3762/bjnano.10.124

• which it reaches a value of 13.6 ± 3 μV/K. This value is comparable to the largest values reported for single-molecule junctions [34]. In order to investigate further the relation between the zero-bias peak and the satellite peaks, we focused on the evolution of differential conductance spectra as a

Electronic conduction during the formation stages of a single-molecule junction

• Atindra Nath Pal,
• Tal Klein,
• Ayelet Vilan and
• Oren Tal

Beilstein J. Nanotechnol. 2018, 9, 1471–1477, doi:10.3762/bjnano.9.138

• , Kolkata 700 106, India 10.3762/bjnano.9.138 Abstract Single-molecule junctions are versatile test beds for electronic transport at the atomic scale. However, not much is known about the early formation steps of such junctions. Here, we study the electronic transport properties of premature junction

• and examine the interplay between these two conductance pathways. Furthermore, the role of this structure in the formation of single-molecule junctions is studied. Our findings reveal the conductance and structural properties of premature molecular junction configurations and uncover the different

• junction; molecular vibration; quantum interference; shot noise; Introduction Single-molecule junctions serve as a versatile atomic-scale laboratory for quantum electronic transport [1][2]. The formation of such molecular junctions, where a molecule is suspended as a bridge between two metallic electrodes

Inelastic electron tunneling spectroscopy of difurylethene-based photochromic single-molecule junctions

• Youngsang Kim,
• Safa G. Bahoosh,
• Dmytro Sysoiev,
• Thomas Huhn,
• Fabian Pauly and
• Elke Scheer

Beilstein J. Nanotechnol. 2017, 8, 2606–2614, doi:10.3762/bjnano.8.261

• two distinct forms of diarylethenes connected to gold electrodes. The combined approach clearly demonstrates that the IET spectra of single-molecule junctions show specific vibrational features that can be used to identify different isomeric molecular states by transport experiments. Keywords

• properties of several species of photochromic molecules in single-molecule junctions with gold electrodes have been investigated extensively to understand the mechanisms of charge transport and optical switching [11][12][13][14][15][16]. Among the photochromic molecules, diarylethene derivatives are

• inelastic charge transport through single-molecule junctions of a bis(furanylmethanthiol)ethene with a fluorinated cyclopentene bridging unit (C5F-ThM; for nomenclature see [22]). Experimentally measured electrical conductance and IET spectra are compared with first-principles calculations in open and

Role of solvents in the electronic transport properties of single-molecule junctions

• Katharina Luka-Guth,
• Sebastian Hambsch,
• Andreas Bloch,
• Philipp Ehrenreich,
• Bernd Michael Briechle,
• Filip Kilibarda,
• Torsten Sendler,
• Dmytro Sysoiev,
• Thomas Huhn,
• Artur Erbe and
• Elke Scheer

Beilstein J. Nanotechnol. 2016, 7, 1055–1067, doi:10.3762/bjnano.7.99

• width, conductance histograms as well as current–voltage characteristics of narrow gaps and discuss them in terms of the Simmons model, which is the standard model for describing transport via tunnel barriers, and the resonant single-level model, often applied to single-molecule junctions. One of our

• controllable break junction; molecular electronics; polar solvent; single-molecule junctions; Introduction The electronic transport properties of single-molecule junctions are actively investigated with the aim to utilize such junctions as functional building blocks in electronic devices [1][2][3][4][5][6][7

• ][8]. A very fruitful method for gathering statistical information on the transport behaviour of single-molecule junctions is the repeated formation and breakage of atomic contacts immersed in a solution containing the molecules under investigation in a suitable solvent. The dissolution of the

Thermo-voltage measurements of atomic contacts at low temperature

• Ayelet Ofarim,
• Bastian Kopp,
• Thomas Möller,
• León Martin,
• Johannes Boneberg,
• Paul Leiderer and
• Elke Scheer

Beilstein J. Nanotechnol. 2016, 7, 767–775, doi:10.3762/bjnano.7.68

• , which are partially not explored thoroughly yet. This includes solid-state semiconducting devices [1] and organic semiconductors, ultrathin metal wires or single-molecule junctions. In particular, the thermopower has become a property of utmost interest because it is decisive for the conversion of

• -electric transport properties of BDT single-molecule junctions are extremely sensitive to the configuration between the two metal leads. The temperature difference across the junction was not measured but calculated using a simulated temperature profile. We have shown recently [19] that a thermo-voltage of

• cryogenic vacuum at low temperatures makes it possible to study atomic-contacts of more reactive metals commonly used in quantum transport studies or in molecular electronics like silver, platinum, aluminum or others. In particular, the study of single-molecule junctions, which at room temperature suffer

Rigid multipodal platforms for metal surfaces

• Michal Valášek,
• Marcin Lindner and
• Marcel Mayor

Beilstein J. Nanotechnol. 2016, 7, 374–405, doi:10.3762/bjnano.7.34

• revealed that the π orbitals of the pyridines contributed to the physisorption of the tripodal platform on gold. Measurements of single-molecule conductance were successfully carried out using modified STM techniques for single-molecule junctions that consisted of the tripodal anchors and a diphenyl

Effects of electronic coupling and electrostatic potential on charge transport in carbon-based molecular electronic junctions

• Richard L. McCreery

Beilstein J. Nanotechnol. 2016, 7, 32–46, doi:10.3762/bjnano.7.4

• relevance of electronic coupling in Au/molecule/Au single molecule junctions by calculating 4t2 for the frontier Au orbitals in the contacts, as modulated by the intervening molecular “bridge” [8]. Changing the substituents on the diamine “bridge” varied the junction conductance, and the theoretical 4t2

Probing the local environment of a single OPE3 molecule using inelastic tunneling electron spectroscopy

• Riccardo Frisenda,
• Mickael L. Perrin and
• Herre S. J. van der Zant

Beilstein J. Nanotechnol. 2015, 6, 2477–2484, doi:10.3762/bjnano.6.257

• electrodes when describing inelastic contributions to transport through single-molecule junctions. Keywords: current–voltage characteristics; DFT calculations; mechanically controllable break junction (MCBJ); molecule–electrode interaction; vibrational modes; Introduction Vibrational degrees of freedom in

• local environment. A similar conclusion has been drawn by Ward et al. for the Raman response of single-molecule junctions [27], in which spectral diffusion and blinking were reported. To relate the peaks in the IETS spectra to the vibrational modes, we used the Amsterdam Density Functional (ADF) package

• between 3, 4, 5a and 5b, above 0.22 V. Conclusion In conclusion, we studied the IETS spectra of OPE3 single-molecule junctions, both as a function of time and electrode separation. We find that the IETS spectra depend heavily on the junction geometry and are sensitive to the local molecular environment

Controlled switching of single-molecule junctions by mechanical motion of a phenyl ring

• Yuya Kitaguchi,
• Satoru Habuka,
• Hiroshi Okuyama,
• Shinichiro Hatta,
• Tetsuya Aruga,
• Thomas Frederiksen,
• Magnus Paulsson and
• Hiromu Ueba

Beilstein J. Nanotechnol. 2015, 6, 2088–2095, doi:10.3762/bjnano.6.213

Large-voltage behavior of charge transport characteristics in nanosystems with weak electron–vibration coupling

• Tomáš Novotný and
• Wolfgang Belzig

Beilstein J. Nanotechnol. 2015, 6, 1853–1859, doi:10.3762/bjnano.6.188

• applied successfully to single-molecule junctions and provides directly their vibrational frequencies from the position of IETS signals [4][7] and, indirectly from the IETS features such as heights of the peaks, also information about electronic and structural properties [8][9]. Theoretical modeling of

Electrical properties and mechanical stability of anchoring groups for single-molecule electronics

• Riccardo Frisenda,
• Simge Tarkuç,
• Elena Galán,
• Mickael L. Perrin,
• Rienk Eelkema,
• Ferdinand C. Grozema and
• Herre S. J. van der Zant

Beilstein J. Nanotechnol. 2015, 6, 1558–1567, doi:10.3762/bjnano.6.159

• ) break junctions. These create and displace atomic-sized electrodes so that reproducibly single-molecule junctions are formed [4][5][6][7]. In the past years it has been shown that the electronic properties of single-molecule junctions depend both on the molecular core and on the interfaces between

• electronic coupling between the molecule and the metal electrode are essential to characterize charge transport in single-molecule junctions and to create new fundamental devices such as molecular motors or molecular machines [26][27]. Several previous studies have shown that stable and reproducible single

• anchoring groups. They find that the conductance is such that BT > SH > NH2> Py > CN, and the attenuation factor, β, that describes the length-dependence of the conductance, follows SH = Py > BT > NH2> CN. While SH and Py groups have been extensively studied and compared in single-molecule junctions, SMe

Electron and heat transport in porphyrin-based single-molecule transistors with electro-burnt graphene electrodes

• Hatef Sadeghi,
• Sara Sangtarash and
• Colin J. Lambert

Beilstein J. Nanotechnol. 2015, 6, 1413–1420, doi:10.3762/bjnano.6.146

• nanometre separation has been proposed using the sp2-bonded two-dimensional carbon-based material, graphene [9]. In addition to the excellent stability and conductivity of graphene even at high temperatures, the significant advantage of graphene electrodes with respect to single-molecule junctions [10][11

Alternative types of molecule-decorated atomic chains in Au–CO–Au single-molecule junctions

• Zoltán Balogh,
• Péter Makk and
• András Halbritter

Beilstein J. Nanotechnol. 2015, 6, 1369–1376, doi:10.3762/bjnano.6.141

• pure Au monoatomic junctions and atomic chains. We identify molecular precursor configurations with somewhat higher conductance, which are formed prior to single-molecule junctions. According to detailed length analysis two distinct types of molecule-affected chain-formation processes are observed, and

• correlation between M1–M2 and A2 in the 2DCH (and similarly the blue conditional histogram for the A2 region exhibits enhanced molecular peaks). All these imply that Au–CO–Au single-molecule junctions are usually not preceded by clean Au monoatomic contacts or atomic chains. There is rather a so-called

• formation and evolution of Au–CO single-molecule junctions. To get more insight into the junction formation we used different statistical analysis methods, such as correlational analysis, 2D conductance–displacement histograms, and conditional histograms. The combination of these techniques can reveal

Electrical characterization of single molecule and Langmuir–Blodgett monomolecular films of a pyridine-terminated oligo(phenylene-ethynylene) derivative

• Henrry M. Osorio,
• Santiago Martín,
• María Carmen López,
• Santiago Marqués-González,
• Simon J. Higgins,
• Richard J. Nichols,
• Paul J. Low and
• Pilar Cea

Beilstein J. Nanotechnol. 2015, 6, 1145–1157, doi:10.3762/bjnano.6.116

• permit the appearance of new functions and technological applications not possible with conventional semiconductors such as quantum information processing [7], quantum computation [8], thermoelectric energy conversion [9], etc. The study of single-molecule junctions has enormously contributed to our

• frontier orbital energies and promotes electron transport by reducing the energy offset between the molecular LUMO and the Fermi level of electrodes [102][103][104]. In particular, DFT-based studies of 1 in single molecule junctions have shown that the total conductance is controlled by eigenchannels

• contrast, compound 1 only shows one conductance value when it is arranged in an LB film, which corresponds to the lower of the two conductance values measured in single molecule junctions [88][105]. This unique conductance value may be induced by the constrained molecular orientation of 1 in a well-ordered

The role of surface corrugation and tip oscillation in single-molecule manipulation with a non-contact atomic force microscope

• Christian Wagner,
• Norman Fournier,
• F. Stefan Tautz and
• Ruslan Temirov

Beilstein J. Nanotechnol. 2014, 5, 202–209, doi:10.3762/bjnano.5.22

• -molecule junctions is still not generally understood and therefore the forces that act in the junction during the manipulation provide more direct information about the conformation of the molecule. One of the first attempts to manipulate large organic adsorbates with the tip of the LT-STM/NC-AFM has been

• the structure and to measure the forces that act in the junction during the manipulation. Although, in principle, the conductance measured with the STM could also be used to control the structure during the manipulation of a molecule, the relation between the conductance and the structure of single

Current–voltage characteristics of single-molecule diarylethene junctions measured with adjustable gold electrodes in solution

• Bernd M. Briechle,
• Youngsang Kim,
• Philipp Ehrenreich,
• Artur Erbe,
• Dmytro Sysoiev,
• Thomas Huhn,
• Ulrich Groth and
• Elke Scheer

Beilstein J. Nanotechnol. 2012, 3, 798–808, doi:10.3762/bjnano.3.89

• : diarylethene; mechanically controllable break-junction; molecular electronics; photoswitching; single-molecule junctions; Introduction Charge transport in single-molecule devices is actively investigated with the aim to realize functional electronic circuits [1][2][3][4], such as switches [5], transistors [4

• conductance level in both states. Naively, the π-conjugation through the entire molecule in the closed form is supposed to show higher conductance than the broken π-system. While this has been confirmed by measurements in molecular ensembles and arrays [18][21] and single-molecule junctions [5][26], the

• −2 G0 could barely be fitted successfully. Apparently, these junctions are not single-molecule junctions either. The fact that I–V’s with higher transmission can be found for the open form can be explained with the weaker steric hindrance that enables the formation of a stable contact even though the

Revealing thermal effects in the electronic transport through irradiated atomic metal point contacts

• Bastian Kopp,
• Zhiwei Yi,
• Daniel Benner,
• Fang-Qing Xie,
• Christian Obermair,
• Thomas Schimmel,
• Johannes Boneberg,
• Paul Leiderer and
• Elke Scheer

Beilstein J. Nanotechnol. 2012, 3, 703–711, doi:10.3762/bjnano.3.80

• two metallic tips both theoretically [4][5][6][7] and experimentally [4][8][9][10][11]. Furthermore the influence of the environment on the conductance of single-molecule junctions [12] has been revealed. In a next step towards molecular electronics, one would like to see such molecules exhibiting

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

• through a quantum-scale device may be uniquely characterized by its transmission eigenvalues τn. Recently, highly conductive single-molecule junctions (SMJ) with multiple transport channels (i.e., several τn > 0) have been formed from benzene molecules between Pt electrodes. Transport through these

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

• . Here we investigate the effect of these small terms using different Hamiltonian models with Hückel, gDFTB and many-body theory to calculate the transport through several single-molecule junctions, finding that terms that are generally thought to only slightly perturb the transport instead produce

• electronics; quantum interference; thermoelectrics; topology; Introduction Destructive interference effects, such as nodes in the transmission function, are a signature of coherence and offer a possible avenue for tuning the transport properties of single-molecule junctions. While not present in all systems

• response, P(ν) is given by the grand canonical ensemble. The transport theory outlined above is generally applicable. Here we focus on single-molecule junctions and utilize a semiempirical Pariser–Parr–Pople (PPP) [35][36][37] π-electron Hamiltonian, which describes Coulomb interactions, π-conjugation and

Effect of the environment on the electrical conductance of the single benzene-1,4-diamine molecule junction

• Shigeto Nakashima,
• Yuuta Takahashi and
• Manabu Kiguchi

Beilstein J. Nanotechnol. 2011, 2, 755–759, doi:10.3762/bjnano.2.83

• -molecule junctions based on intrinsic factors [4][5], uncertainties still remain, and the effects of the environment on the conductance of the single-molecule junction are still unclear. In solution, solvent molecules can interact with the molecule bridging the metal electrodes, and/or with the metal

• -molecule junctions were fabricated in an electrochemical cell mounted in a chamber, which was filled with high-purity N2 gas (purity >99.999%) in order to avoid any effects of oxygen and water in the air. The conductance measurements were performed by using electrochemical STM (Pico-SPM, Molecular Imaging

• coefficient at site r, and the kth MO energy, respectively. The infinitesimal ηk is determined by Green’s function and DOS [3]. The conductance of the single molecule junction depends on the parameters of t, ρ, Crk, εk, and ηk. While advances have been made in the understanding of the conductance of single

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

• conductance of single-molecule junctions of oligophenylene ethynylene (OPE)-type molecules contacted to gold leads. We have chosen three rigid dithiolated molecular wires with different conjugation patterns: An anthracene-based linearly conjugated wire (AC), an anthraquinone-based cross-conjugated wire (AQ

• a high yield of single-molecule junctions is obtained in the absence as well as in the presence of in situ deprotecting agents, such as tetrabutyl ammonium hydroxide or triethylamine. As a consequence, and to keep the number of different species in the sample solution to a minimum [57], we performed

• ]. A tentative scenario is illustrated in Figure 10C. Both processes may occur sequentially if more than one molecule is trapped in the junction. This interpretation is based on experimentally observed “stacking” trends in single-molecule junctions formed by dithiolated or monothiolated OPE-type

Transport through molecular junctions

• Jan M. van Ruitenbeek

Beilstein J. Nanotechnol. 2011, 2, 691–692, doi:10.3762/bjnano.2.74

• (vibrons). This coupling is predicted to influence transport in dramatic ways as it may destroy the coherence of charge carriers on the molecules and can lead to strong nonequilibrium effects. Many exciting predictions have been discussed in the recent literature showing unique features of single-molecule

• junctions. These properties can be designed and controlled by chemists. Studying them experimentally requires creating an interface between the molecules and at least two metallic leads. Standard nanofabrication techniques fall short by more than an order of magnitude in the distance and precision required