Reasons and remedies for the agglomeration of multilayered graphene and carbon nanotubes in polymers

• Rasheed Atif and
• Fawad Inam

Beilstein J. Nanotechnol. 2016, 7, 1174–1196, doi:10.3762/bjnano.7.109

• , the nanotube exhibits electron transport properties of a metal, while it behaves as a semiconductor if above condition is not satisfied. The semiconducting CNTs have varying bandgaps [36]. The bandgap for semi-conducting CNT is inversely proportional to the diameter of nanotube. The values of about

Reorientation of single-wall carbon nanotubes in negative anisotropy liquid crystals by an electric field

• Amanda García-García,
• Ricardo Vergaz,
• José F. Algorri,
• Gianluigi Zito,
• Teresa Cacace,
• Antigone Marino,
• José M. Otón and
• Morten A. Geday

Beilstein J. Nanotechnol. 2016, 7, 825–833, doi:10.3762/bjnano.7.74

• could be caused by SWCNTs that do not recover their original planar orientation. As these SWCNTs are in a position perpendicular to the contacts, the electron transport is facilitated by the longitudinal axis. Threshold voltage In order to determine a potential threshold voltage for the SWCNT switching

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

• changes from hole to electron transport, when the number of thiophene dioxide monomers in the molecular backbone increases. A very elegant method for simultaneous measurements of the conductance and the thermopower has recently been presented by Kim et al. who create an oscillating temperature difference

Gold nanoparticles covalently assembled onto vesicle structures as possible biosensing platform

• M. Fátima Barroso,
• M. Alejandra Luna,
• Juan S. Flores Tabares,
• Cristina Delerue-Matos,
• N. Mariano Correa,
• Fernando Moyano and
• Patricia G. Molina

Beilstein J. Nanotechnol. 2016, 7, 655–663, doi:10.3762/bjnano.7.58

• surface was modified with LUVs formed at different SH/DOPC ratios, a decrease of the peak intensity of [Fe(CN)6]4− and a displacement of the peak potentials (oxidation and reduction) was observed (Figure 5b). This behaviour can be explained by invoking the resistance to the electron transport generated by

Charge and heat transport in soft nanosystems in the presence of time-dependent perturbations

• Alberto Nocera,
• Carmine Antonio Perroni,
• Vincenzo Marigliano Ramaglia and
• Vittorio Cataudella

Beilstein J. Nanotechnol. 2016, 7, 439–464, doi:10.3762/bjnano.7.39

• the agreement between the two approaches is still good. Actually, the exact approach at low molecule occupation slightly favors a small transfer of spectral weight at high frequency. In any case, the strong similarities in the spectral function will point out to analogous behaviours of electron

• transport properties within the two approaches. In conclusion, we can say that the semiclassical adiabatic approach correctly describes the system down to quite low temperatures. In the linear response regime, without time perturbations, the spectral function allows one to derive all the Green’s functions

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

• motivated in the 1970s from a rather theoretical point of view by Kuhn and Möbius [1] and later by Aviram and Ratner [2], tries to get molecules wired and explore their potential use as electronic devices, logic gates or sensing entities [3][4][5]. The understanding of the fundamentals of electron transport

• mobility of the molecules and the influence of the additional alkyl chains led to an increase of surface coverage, and improve the self-assembly process. But these long alkyl chains are forming an insulating adlayer that reduces the electron transport between the metal electrodes, what diminish their

• resistance when small voltage biases are applied, which makes selenol a better anchoring group with a well-defined electronic coupling and faster electron transport to gold electrodes than thiol for further elaboration toward single-molecule devices. These results are consistent with the trends reported

Molecular machines operating on the nanoscale: from classical to quantum

• Igor Goychuk

Beilstein J. Nanotechnol. 2016, 7, 328–350, doi:10.3762/bjnano.7.31

• a quantum prefactor, where Vtun is the tunneling coupling, and λ is the reorganization energy of the medium. The energy released in the electron transport is used to pump protons against their electrochemical gradient, Δμp, which corresponds to 2πfL within the previous model. Hence, R = Δμp/|Δμ|. Of

Molecular machines and devices

• Jan van Ruitenbeek

Beilstein J. Nanotechnol. 2016, 7, 310–311, doi:10.3762/bjnano.7.29

• machines. Molecular electronics is currently being developed mostly at the interface between organic chemistry and nanophysics, leaning strongly towards the fundamental understanding of electron transport at the smallest scale and applications in nanoelectronics. The second topic, one-dimensional

• in biology. Spiros Skourtis introduced the audience to the remarkable discovery of electron transport along micrometer long biomolecular wires, so-called pilli, growing as extracellular appendages from the surface of certain bacteria. The present understanding of the electron-conduction mechanism is

• experimental evidence is presented. The progress in theory and experiment on single-molecule electron transport can be judged from many contributions in this volume. On the other hand, some subjects are not as well-covered, including electron transport in biomolecules and one-dimensional conductors. This is

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

• difficult to calculate accurately, it does provide a basis for the “vacuum level shift” observed in many experiments, including transport and ultraviolet photoelectron spectroscopy of molecular layers on conductors. Keywords: molecular junction electron transport density functional theory molecular devices

• striking similarity to experimental results from a variety of laboratories and paradigms [1][5][31][53]. Electron transport across thin organic layers often decays exponentially with layer thickness, with an “attenuation length (β)" equal to the slope of a plot of the natural log of transport rate vs layer

• attributed to I. M. Koltoff: “theory guides, experiment decides”. The purpose of the current paper is to identify some of the “guides” that apply to how molecular structure affects electron transport in carbon-based molecular electronic devices. With that objective in mind, several observations are available

Thermoelectricity in molecular junctions with harmonic and anharmonic modes

• Bijay Kumar Agarwalla,
• Jian-Hua Jiang and
• Dvira Segal

Beilstein J. Nanotechnol. 2015, 6, 2129–2139, doi:10.3762/bjnano.6.218

• , Suzhou 215006, China 10.3762/bjnano.6.218 Abstract We study charge and energy transfer in two-site molecular electronic junctions in which electron transport is assisted by a vibrational mode. To understand the role of mode harmonicity/anharmonicity in transport behavior, we consider two limiting

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

• and can successfully lift up the molecules. The computational approach was detailed in [12]. Briefly, we used Kohn–Sham density functional theory (DFT) implemented in VASP [15][16] to obtain the atomic structure and total energy using the optPBE-vdW [17] exchange-correlation functional. Electron

• transport was computed with the DFT-based codes TranSIESTA [18][19] and Inelastica [20] using GGA-PBE [21] for the junctions connected to semi-infinite electrodes. The voltage-induced atomic forces were computed as the difference in the Hellman–Feynman force on each atom between the finite sample voltage

Simple and efficient way of speeding up transmission calculations with k-point sampling

• Jesper Toft Falkenberg and
• Mads Brandbyge

Beilstein J. Nanotechnol. 2015, 6, 1603–1608, doi:10.3762/bjnano.6.164

• illustrated the method using electron transport through graphene nano-structures and k-point averaging of transmission functions. However, the method is generally applicable also to phonon transport and to other functions such as density of states or other types of interpolation parameters such as

Formation of pure Cu nanocrystals upon post-growth annealing of Cu–C material obtained from focused electron beam induced deposition: comparison of different methods

• Aleksandra Szkudlarek,
• Alfredo Rodrigues Vaz,
• Yucheng Zhang,
• Andrzej Rudkowski,
• Czesław Kapusta,
• Rolf Erni,
• Stanislav Moshkalev and
• Ivo Utke

Beilstein J. Nanotechnol. 2015, 6, 1508–1517, doi:10.3762/bjnano.6.156

• , post-irradiation experiments with electrons energy of 5 keV were shown to be already effective to change the electron transport mechanisms in Pt–C and W–C FEBID deposits [27][28][29]. TEM observations In Figure 6, the results of in situ TEM annealing experiments performed on the line and square deposit

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

• on the electron transport since they have high orbital energies far from the HOMO–LUMO resonances. Although the current mostly passes through the edge of the ribbon, it does not have much effect on the transport due to the weak coupling between the anchor and electrode surfaces. We used the tight

Surface excitations in the modelling of electron transport for electron-beam-induced deposition experiments

• Francesc Salvat-Pujol,
• Roser Valentí and
• Wolfgang S. Werner

Beilstein J. Nanotechnol. 2015, 6, 1260–1267, doi:10.3762/bjnano.6.129

• /bjnano.6.129 Abstract The aim of the present overview article is to raise awareness of an essential aspect that is usually not accounted for in the modelling of electron transport for focused-electron-beam-induced deposition (FEBID) of nanostructures: Surface excitations are on the one hand responsible

• present a general perspective of recent works on the subject of surface excitations and on low-energy electron transport, highlighting the most relevant aspects for the modelling of electron transport in FEBID simulations. Keywords: focused-electron-beam-induced deposition (FEBID); Monte Carlo simulation

• of electron transport; surface excitations; secondary-electron emission; Introduction An accurate modelling of the energy losses of electrons traversing a solid surface is instrumental for a quantitative understanding of a series of techniques exploiting transmitted, reflected, or emitted electrons

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

• 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

Charge carrier mobility and electronic properties of Al(Op)₃: impact of excimer formation

• Andrea Magri,
• Pascal Friederich,
• Bernhard Schäfer,
• Valeria Fattori,
• Xiangnan Sun,
• Timo Strunk,
• Velimir Meded,
• Luis E. Hueso,
• Wolfgang Wenzel and
• Mario Ruben

Beilstein J. Nanotechnol. 2015, 6, 1107–1115, doi:10.3762/bjnano.6.112

• with which electron and/or holes move within the organic layer is crucial to device performance [2]. Since its first implementation in OLEDs devices [3], the small p-conjugated tris(8-hydroxyquinolinolate)aluminum(III) (Alq3) is still the most commonly used and studied electron transport material among

• −2.07 V. The subsequent formation of the mono-, di-, and tri-anion is assumed to occur due to the systematic reduction of each phenalenyl moiety [25]. Since electron transport can be represented as a series of consecutive redox processes, the reversible electrochemical reduction with an adequately high

Pt- and Pd-decorated MWCNTs for vapour and gas detection at room temperature

• Hamdi Baccar,
• Atef Thamri,
• Pierrick Clément,
• Eduard Llobet and
• Adnane Abdelghani

Beilstein J. Nanotechnol. 2015, 6, 919–927, doi:10.3762/bjnano.6.95

• affects the sensitivity and selectivity of the hybrid carbon nanotube material. The idea is to use nanoparticles that donate or accept charge upon adsorption of vapours or gas molecules, which eventually alters the electron transport in the carbon nanotube [26]. Kumar et al. published the first

Graphene quantum interference photodetector

• Mahbub Alam and
• Paul L. Voss

Beilstein J. Nanotechnol. 2015, 6, 726–735, doi:10.3762/bjnano.6.74

• as high electrical mobility, high thermal conductivity, high mechanical strength, linear energy dispersion around the Dirac point and strong light absorption from near-infrared to visible wavelengths [1][2][3]. Graphene also exhibits ballistic electron transport over unusually long lengths [4][5][6

Entropy effects in the collective dynamic behavior of alkyl monolayers tethered to Si(111)

• Christian Godet

Beilstein J. Nanotechnol. 2015, 6, 583–594, doi:10.3762/bjnano.6.60

• electron transport [7][25][26][27][28][29][30][31][32] properties. In order to understand the behavior of nanometer-thick 2D assemblies of molecules tethered to metallic or semiconductor surfaces, the concepts developed for bulk organic solids should be revisited by also considering molecular coverage

• ] conformational changes on electron transport properties have rarely been explicitly described. In this context, this admittance spectroscopy study emphasizes a collective dynamic behavior of linear saturated (n-alkyl) chains tethered to Si(111). Dynamic properties are very sensitive to structure and conformation

• electrostatic pressure across the nanometer-thick insulating layer. This effect is expected to be stronger with shorter alkyl chains (thinner OML in Equation 2) with possible implications on electron transport through molecular tunnel barriers. Further work is required to investigate its dependence on the OML

Electrical response of liquid crystal cells doped with multi-walled carbon nanotubes

• Amanda García-García,
• Ricardo Vergaz,
• José F. Algorri,
• Xabier Quintana and
• José M. Otón

Beilstein J. Nanotechnol. 2015, 6, 396–403, doi:10.3762/bjnano.6.39

• semiconductive, while in multi-walled CNTs (MWCNT) it is always metallic [10]. The almost one-dimensional structure leads to a long-range ballistic electron transport in metallic CNTs [10][11]. LCs are self-organized anisotropic fluids, whose long-range orientation (called director) can be induced by surface

Liquid-phase exfoliated graphene: functionalization, characterization, and applications

• Mildred Quintana,
• Jesús Iván Tapia and
• Maurizio Prato

Beilstein J. Nanotechnol. 2014, 5, 2328–2338, doi:10.3762/bjnano.5.242

• deposition of the nanohybrid showed better performance when compared with similar substrates produced with functionalized CNTs. Our results support the importance of the rational chemical design of the carbon platform for the preservation of electron transport and accumulation processes associated with

Hybrid spin-crossover nanostructures

• Carlos M. Quintero,
• Gautier Félix,
• Iurii Suleimanov,
• José Sánchez Costa,
• Gábor Molnár,
• Lionel Salmon,
• William Nicolazzi and
• Azzedine Bousseksou

Beilstein J. Nanotechnol. 2014, 5, 2230–2239, doi:10.3762/bjnano.5.232

• proposed two mechanisms: first, since the oscillator strength of the charge transfer (CT) bands increases in the LS state, it is possible that the injected electrons transit from the π orbital of the dpp ligand to the d orbital of the iron centers, giving an additional electron transport path from the

• cathode to the anode through the SCO complex. Second, a shift in the energy level of the molecular orbital concerning the electron transport in the SCO complex relative to that of Chl a (Figure 6b) [30] is possible. Thus, at high temperatures (HS state) the injected electrons effectively excite the Chl a

• molecules, leading to EL emission. Conversely, at low temperatures (LS state) the electron transport orbital of the [Fe(dpp)2](BF)4 shifts to a level lower than that of Chl a and as a result, the electrons flow exclusively into the SCO complex, preventing the formation of excited Chl a. Even though the

Advances in NO₂ sensing with individual single-walled carbon nanotube transistors

• Kiran Chikkadi,
• Matthias Muoth,
• Cosmin Roman,
• Miroslav Haluska and
• Christofer Hierold

Beilstein J. Nanotechnol. 2014, 5, 2179–2191, doi:10.3762/bjnano.5.227

• influence the electron transport in the devices by changing the transfer characteristics. However, the devices also react strongly to charges in their vicinity, which leads to problems such as hysteresis and noise. We will examine these effects in detail in the next sections. Effect of adsorbate gases The

• nature of this interaction. From a theoretical perspective, the effect of NO2 on the electron transport in the SWNT must be explored in more detail, and a hypothesis that consistently explains the observations from several papers must be developed. As it has increasingly grown clear, the cleanliness and

Probing the electronic transport on the reconstructed Au/Ge(001) surface

• Franciszek Krok,
• Mark R. Kaspers,
• Alexander M. Bernhart,
• Marek Nikiel,
• Benedykt R. Jany,
• Paulina Indyka,
• Mateusz Wojtaszek,
• Rolf Möller and
• Christian A. Bobisch

Beilstein J. Nanotechnol. 2014, 5, 1463–1471, doi:10.3762/bjnano.5.159

• (001) surface exhibits a two dimensional conductance channel on a micrometre-scale averaging across several Au-reconstructed 1D domains [10]. Scanning tunnelling microscopy (STM) and various STM-based methods are excellent tools to study the topographic structure, the electronic structure, and electron

• transport phenomena of conducting surfaces at the limit of lateral resolution. By performing scanning tunnelling potentiometry (STP) [11] we tried to study the lateral variation of the electrochemical potential µec (called potential in the following) at the boundary between two rotated Au wire-like domains