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

Sublattice asymmetry of impurity doping in graphene: A review

• James A. Lawlor and
• Mauro S. Ferreira

Beilstein J. Nanotechnol. 2014, 5, 1210–1217, doi:10.3762/bjnano.5.133

• sublattices, the band gap, although smaller, was shown to still exist. This is promising for scaleability where perfect asymmetric doping may not always be realizable. Beyond the realization of quasi-ballistic electron transport, sublattice segregated systems can also be used to induce magnetism [19][48][49

• ][50] and produce spin-polarized current [51][52]. Much work has been done studying how the placement of dopants affects the properties of nanoribbons. DFT approaches, using a periodic system of dopants [53][54], and a more general Kubo–Greenwood approach [37] have shown that electron transport is

Gas sensing with gold-decorated vertically aligned carbon nanotubes

• Prasantha R. Mudimela,
• Mattia Scardamaglia,
• Oriol González-León,
• Nicolas Reckinger,
• Rony Snyders,
• Eduard Llobet,
• Carla Bittencourt and
• Jean-François Colomer

Beilstein J. Nanotechnol. 2014, 5, 910–918, doi:10.3762/bjnano.5.104

• , it was shown that the sensitivity of the CNT gas sensor depends on nanocluster size and sensor working temperature [13][14][15][16][17]. Indeed, the nanoscale size of the metal cluster is necessary to maximize the effect of the gas adsorption and so to affect the electron transport in the CNTs by

Optical modeling-assisted characterization of dye-sensitized solar cells using TiO₂ nanotube arrays as photoanodes

• Jung-Ho Yun,
• Il Ku Kim,
• Yun Hau Ng,
• Lianzhou Wang and
• Rose Amal

Beilstein J. Nanotechnol. 2014, 5, 895–902, doi:10.3762/bjnano.5.102

• efficiency by promoting light scattering [3][4][5]. In addition, the electron transport or recombination rate could be influenced by physical properties such as porosity, morphology, crystallinity, and uniformity of the TiO2 structure [6][7][8][9]. TiO2 photoelectrode candidate materials with different

• TiO2 nanoparticles, vertically well-ordered TNT-based DSSCs presented an enhanced electron transport by efficiently reducing the recombination possibility of photogenerated charge carriers through minimizing the trapping sites that normally exist in the grain boundaries of randomly oriented TiO2

• performances and electron transport properties of the fabricated DSSCs with different thickness of the TNT photoanodes are investigated. The simplified standard structures under the experimental condition are simulated by using a generalized transfer matrix method (GTMM) [15][16]. The comparison of the

Enhancement of photocatalytic H₂ evolution of eosin Y-sensitized reduced graphene oxide through a simple photoreaction

• Weiying Zhang,
• Yuexiang Li,
• Shaoqin Peng and
• Xiang Cai

Beilstein J. Nanotechnol. 2014, 5, 801–811, doi:10.3762/bjnano.5.92

• ) sheet of sp2-hybrized carbon, has received tremendous research interests based on its extraordinary electronic, thermal, optical and excellent electron transport properties [21][22]. Graphene can be easily obtained by reducing graphene oxide (GO), which is a cheap and scalable preparation method [23][24

Nanostructure sensitization of transition metal oxides for visible-light photocatalysis

• Hongjun Chen and
• Lianzhou Wang

Beilstein J. Nanotechnol. 2014, 5, 696–710, doi:10.3762/bjnano.5.82

• particulate structure and found a more efficient means of separating electron–hole pairs on the tubular TiO2 architectures, leading to an improved performance of the CdS photosensitized tubular TiO2 architectures [32]. Figure 3 outlines the electron transport in these two different architectures. Kim et al

Analytical development and optimization of a graphene–solution interface capacitance model

• Hediyeh Karimi,
• Rasoul Rahmani,
• Reza Mashayekhi,
• Leyla Ranjbari,
• Amir H. Shirdel,
• Niloofar Haghighian,
• Parisa Movahedi,
• Moein Hadiyan and
• Razali Ismail

Beilstein J. Nanotechnol. 2014, 5, 603–609, doi:10.3762/bjnano.5.71

• these days. Geim, in 2004, demonstrated that the six-membered rings are the basis of all carbon materials in electrochemical biosensor research [7]. The remarkable electrical properties of graphene such as fast electron transport, tunable energy bandgap, high thermal conductivity, and ballistic

Dye-sensitized Pt@TiO₂ core–shell nanostructures for the efficient photocatalytic generation of hydrogen

• Jun Fang,
• Lisha Yin,
• Shaowen Cao,
• Yusen Liao and
• Can Xue

Beilstein J. Nanotechnol. 2014, 5, 360–364, doi:10.3762/bjnano.5.41

• the excitation of ErB and TiO2, which plays an important role in the photocatalytic hydrogen generation. The observed synergic effect could be attributed to the electron transport in TiO2 particles. Since the dye-sensitization induces an electron transfer from the excited ErB to TiO2, these electrons

Simulation of electron transport during electron-beam-induced deposition of nanostructures

• Francesc Salvat-Pujol,
• Harald O. Jeschke and
• Roser Valentí

Beilstein J. Nanotechnol. 2013, 4, 781–792, doi:10.3762/bjnano.4.89

• -induced growth of tungsten nanostructures on SiO2 substrates by using a Monte Carlo simulation of the electron transport. This study gives a quantitative insight into the deposition of energy and charge in the substrate and in the already existing metallic nanostructures in the presence of the electron

• during post-growth electron-beam treatments. Keywords: electron backscattering; electron transport; (F)EBID; Monte Carlo simulation; PENELOPE; Introduction Electron-beam-induced deposition (EBID) [1][2][3] is a suitable method for the template-free fabrication of nanostructures. Molecules of a

• already for energies below a few hundred eV. The same absorption energy is used for the secondary electrons that are generated in the shower. Finally, to obtain our simulation results, we have sampled 108 trajectories. Results To provide a first visual insight into the electron transport process in the

Influence of particle size and fluorination ratio of CF_x precursor compounds on the electrochemical performance of C–FeF₂ nanocomposites for reversible lithium storage

• Ben Breitung,
• M. Anji Reddy,
• Venkata Sai Kiran Chakravadhanula,
• Michael Engel,
• Christian Kübel,
• Annie K. Powell,
• Horst Hahn and
• Maximilian Fichtner

Beilstein J. Nanotechnol. 2013, 4, 705–713, doi:10.3762/bjnano.4.80

• fluorides, a well conducting nanoscale matrix is required to ensure the electron transport to the active material. Micrometer-sized metal fluoride particles are too big to accommodate the transfer of electric charge, and their capacity fades rapidly with cycling. Hence, a nanoscale dispersion of the