Scanning probe microscopy studies on the adsorption of selected molecular dyes on titania

• Jakub S. Prauzner-Bechcicki,
• Lukasz Zajac,
• Piotr Olszowski,
• Res Jöhr,
• Antoine Hinaut,
• Thilo Glatzel,
• Bartosz Such,
• Ernst Meyer and
• Marek Szymonski

Beilstein J. Nanotechnol. 2016, 7, 1642–1653, doi:10.3762/bjnano.7.156

• context, the knowledge of properties of the titania–sensitizer junction is essential for designing efficient devices. Consequently, studies on the adsorption of organic dyes on titania surfaces and on the influence of the adsorption geometry on the energy level alignment between the substrate and an

• charge separation and transport functions are separated. Now, the properties of the semiconductor–sensitizer junction may increase the conversion efficiency in the photovoltaic device. In view of this, it is essential to study the adsorption properties and the charge transfer of organic dyes on the

• determinants, but some of them still play a pivotal role. Second, once the molecular layers are obtained, one may try to seek for correlations between the morphology of the layer and the electrical properties of the junction. An interesting issue is the evolution of excited charge carriers in the molecular

Nonlinear thermoelectric effects in high-field superconductor-ferromagnet tunnel junctions

• Stefan Kolenda,
• Peter Machon,
• Detlef Beckmann and
• Wolfgang Belzig

Beilstein J. Nanotechnol. 2016, 7, 1579–1585, doi:10.3762/bjnano.7.152

• investigate the dependence of thermoelectric currents on the thermal excitation, as well as on the presence of a dc bias voltage across the junction. Conclusion: Large thermoelectric effects are observed in superconductor/ferromagnet and superconductor/normal-metal hybrid structures. The spin-independent

• -insulator-superconductor junction. Theory In the linear response regime the Seebeck and the Peltier coefficients are related by the Onsager reciprocity relation. Hence a measurement of one determines the other. This is not the case in the nonlinear regime anymore. In the following we derive a generalization

• current from the measure thermally induced charge current. We consider a metal coupled to a superconductor by a tunnel contact, with normal-state tunnel conductance GT. The metal can be a normal metal or a ferromagnet, in which case the junction conductance has a finite spin polarization P. In that

Filled and empty states of Zn-TPP films deposited on Fe(001)-p(1×1)O

• Gianlorenzo Bussetti,
• Alberto Calloni,
• Rossella Yivlialin,
• Andrea Picone,
• Federico Bottegoni and
• Marco Finazzi

Beilstein J. Nanotechnol. 2016, 7, 1527–1531, doi:10.3762/bjnano.7.146

• ]. The changes of the interface dipole, as a function of the film thickness, can thus give a first characterization to evaluate possible barriers that affect the transport properties of the junction. Finally, we summarize in the Table 1 the main energy positions of the R/Ph-HOMO and R/Ph-LUMO molecular

Effect of triple junctions on deformation twinning in a nanostructured Cu–Zn alloy: A statistical study using transmission Kikuchi diffraction

• Silu Liu,
• Xiaolong Ma,
• Lingzhen Li,
• Liwen Zhang,
• Patrick W. Trimby,
• Xiaozhou Liao,
• Yusheng Li,
• Yonghao Zhao and
• Yuntian Zhu

Beilstein J. Nanotechnol. 2016, 7, 1501–1506, doi:10.3762/bjnano.7.143

• -pressure torsion. It was found that in 83% of grains containing twins, at least one twin intersects with a triple junction. This suggests that triple junctions could have promoted the nucleation of deformation twins. It should be cautioned that this technique might be unable to detect extremely small

• intersects with a triple junction. It has been reported that the area nearby a triple junction would emit or absorb free volumes to promote the emission of partial dislocations [12] and then emitted partial dislocations would induce the growth of stacking faults or twins [14][15]. Therefore, a twin meeting

• the triple junction could be nucleated from the triple junction. The statistics in Table 1 reveals that 248 out of 300 twinned grains (83%) have at least a twin connected with a triple junction. Two grain size subsets, 30–100 nm and 100–200 nm, are selected to make a comparison in order to avoid

Nanostructured germanium deposited on heated substrates with enhanced photoelectric properties

• Ionel Stavarache,
• Valentin Adrian Maraloiu,
• Petronela Prepelita and
• Gheorghe Iordache

Beilstein J. Nanotechnol. 2016, 7, 1492–1500, doi:10.3762/bjnano.7.142

• the n-Si substrate was grounded. In this configuration, the bias voltage is applied across the series combination of junctions, namely at the ITO/Ge:SiO2 interface, the Ge:SiO2 film region, and the junction situated at Ge:SiO2/Si interface [34]. The rectifying behavior (102 rectification ratio at 1 V

The effect of dry shear aligning of nanotube thin films on the photovoltaic performance of carbon nanotube–silicon solar cells

• Benedikt W. Stolz,
• Daniel D. Tune and
• Benjamin S. Flavel

Beilstein J. Nanotechnol. 2016, 7, 1486–1491, doi:10.3762/bjnano.7.141

• unanswered. What has been established is that, as one should expect, the quality of the junction plays a large role in overall performance. Since the underlying silicon base is usually a high-grade monocrystalline material, junction quality is dominated by aspects relating to the nanotube thin film. An

Adiabatic superconducting cells for ultra-low-power artificial neural networks

• Andrey E. Schegolev,
• Nikolay V. Klenov,
• Igor I. Soloviev and
• Maxim V. Tereshonok

Beilstein J. Nanotechnol. 2016, 7, 1397–1403, doi:10.3762/bjnano.7.130

• ), making them relatively slow and hardware/power consumable. The basic element of a superconducting circuit is the nonlinear Josephson junction, which is about three orders faster than a conventional transistor. In contrast to semiconductor neurons, the superconducting one typically consists of just a few

• as a neuron whose activation function usually has a sigmoid-like shape. We start our pursuit of the MLP artificial neuron with an analysis of a simple quantron (or single-junction superconducting interferometer, Figure 1a) transfer function. This function links the applied magnetic flux, ΦX, with

• quantron loop and the relationship between the current through the Josephson junction and its phase, φ, are as follows: One can represent output current as a parametric function [25] and then plot the nonlinear flux-to-current characteristic, as shown in Figure 1b. Note that the resulting transfer function

Ammonia gas sensors based on In₂O₃/PANI hetero-nanofibers operating at room temperature

• Qingxin Nie,
• Zengyuan Pang,
• Hangyi Lu,
• Yibing Cai and
• Qufu Wei

Beilstein J. Nanotechnol. 2016, 7, 1312–1321, doi:10.3762/bjnano.7.122

• characteristics of all In2O3/PANI nanofibers clearly exhibit a nonlinear behavior and it can be observed the rectifying behavior in Figure 4, which might result from the p–n junction between the p-type PANI and n-type In2O3 [28][29]. It can be observed that the current of In2O3/PANI showed exponential rise at low

• form a typical ohmic system [31]. Thus, it can be confirmed that a p–n junction between PANI and In2O3 had been formed. Gas sensing properties To study the ammonia sensing behavior of the sensors with different ratios of In2O3 to aniline, the dynamic response of the sensors based on pure PANI and In2O3

• section [40]. Simultaneously, the variation of the PANI region width would have effects on the width of the In2O3 region and on the p–n junction. The electrons of In2O3 and holes of PANI move in opposite directions until the new Fermi level (EF-NH3) reaches equilibrium. In this process, the electron

Fabrication and characterization of branched carbon nanostructures

• Sharali Malik,
• Yoshihiro Nemoto,
• Hongxuan Guo,
• Katsuhiko Ariga and
• Jonathan P. Hill

Beilstein J. Nanotechnol. 2016, 7, 1260–1266, doi:10.3762/bjnano.7.116

• electronic properties, it is well known that in carbon nanotube networks the junction resistance controls the overall performance [17]. Therefore, in addition to b-MWCNTs/composite applications, the enhanced electrical properties of networks arising within this new material has major potential benefits for

Photocurrent generation in carbon nanotube/cubic-phase HfO₂ nanoparticle hybrid nanocomposites

• Protima Rauwel,
• Augustinas Galeckas,
• Martin Salumaa,
• Frédérique Ducroquet and
• Erwan Rauwel

Beilstein J. Nanotechnol. 2016, 7, 1075–1085, doi:10.3762/bjnano.7.101

• generally weak with respect to the dark current in the absence of additional Schottky or p–n junction to enhance the photoresponse [63]. This agrees well with the PL measurements of the nanocomposites (see Figure 2) showing no additional spectral features apart from emission peaks associated with Hf3+ 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

• 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

• to the metal/molecule/metal junction alone, neglecting the contributions Gs of the solvents. This assumption is justified if GJ is much larger than Gs. Except for the seminal studies by Grüter et al. [9][10] the role of the solvent for the transport properties of single-molecule contacts has been

• level alignment [9][10][13][21]. In general, a molecular junction is not formed in all of the breaking curves, but the majority of curves show smooth or noisy distance dependence. These curves are interpreted as tunnelling through the solvent that has no influence on the apparent conductance values of

Modelling of ‘sub-atomic’ contrast resulting from back-bonding on Si(111)-7×7

• Adam Sweetman,
• Samuel P. Jarvis and
• Mohammad A. Rashid

Beilstein J. Nanotechnol. 2016, 7, 937–945, doi:10.3762/bjnano.7.85

• obtained during imaging of planar organic molecules [3][4]. An important development in the interpretation of sub-molecular resolution imaging has been the explicit consideration of deflection (i.e., mechanical deformation) in the tip–sample junction [5][6][7], which can result in contrast enhancement [6

• end of the bulk tip material, and a single passivated probe particle. In order to simulate the mechanical deformation in the tip–sample junction, the probe particle is allowed to move around the tip base, and acts as a flexible end of the model tip. To model the Si(111)-7×7 surface we imported a

• the tip–sample junction plays in explaining the image contrast, they do not necessarily reveal the origin of the features. Beyond the computational simplicity of the L-J model, an additional advantage compared to more sophisticated modelling techniques is that it is easy to construct “toy” systems

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

• atomic-sized gold contacts at low temperature. For these measurements a mechanically controllable break junction (MCBJ) system is used and a laser source generates a temperature difference of a few kelvins across the junction to create a thermo-voltage. Since the temperature difference enters directly

• measurement of the resistance change due to laser heating of sensor leads on both sides next to the junction. Our results for the measured thermopower are in agreement with recent reports in the literature. Keywords: atomic contacts; finite element simulations; laser heating; low temperature; mechanically

• controllable break-junction; temperature determination; thermopower; Introduction The energy and heat management in electronic devices has become a challenge in recent years due to the down-scaling of electronic components to the nanoscale, where the transport is governed by quantum-mechanical properties

Magnetic switching of nanoscale antidot lattices

• Ulf Wiedwald,
• Joachim Gräfe,
• Kristof M. Lebecki,
• Maxim Skripnik,
• Felix Haering,
• Gisela Schütz,
• Paul Ziemann,
• Eberhard Goering and
• Ulrich Nowak

Beilstein J. Nanotechnol. 2016, 7, 733–750, doi:10.3762/bjnano.7.65

• have a common junction, a residual magnetic charge can be defined, which is the source of the magnetic stray field resulting in the contrast in the MFM investigations [16]. This interpretation is supported by the micromagnetic modelling of the system. Figure 6c shows the simulated magnetisation pattern

Tight junction between endothelial cells: the interaction between nanoparticles and blood vessels

• Yue Zhang and
• Wan-Xi Yang

Beilstein J. Nanotechnol. 2016, 7, 675–684, doi:10.3762/bjnano.7.60

• blood vessels, which are the sites of phosphorylation of tight junction proteins (claudins, occludins, and ZO (Zonula occludens)) proteins, oxidative stress and shear stress. We propose a connection between the presence of nanoparticles and the regulation of the tight junction, which might be the key

• approach for nanoparticles to penetrate endothelial layers and then have an impact on other tissues and organs. Keywords: blood vessels; endothelial cells; nanoparticles; oxidative stress; tight junction; Introduction Products related to nanoparticles (NPs) are increasingly growing in number. We can

• vessels, in particular about (1) NPs pass through the endothelial layer of blood vessels and (2) NPs cause cytotoxicity in surrounding tissues under the endothelial layer. Endothelial cells and tight junction The endothelium provides a thin layer of cells that covers the internal surface of blood vessels

First-principles study of the structure of water layers on flat and stepped Pb electrodes

• Xiaohang Lin,
• Ferdinand Evers and
• Axel Groß

Beilstein J. Nanotechnol. 2016, 7, 533–543, doi:10.3762/bjnano.7.47

• coverage of adsorbed ions on the junction [19][20][21]. As part of this ongoing research programme, here we present a detailed computational study on the structural and vibrational properties of water layers on flat and stepped Pb surfaces. Besides its relevance for the understanding of microscopic details

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

• electronic and vibrational degrees of freedom. Nanoelectromechanical systems (NEMS) are devices similar to molecular junctions. Typically, they consist of a nanobeam resonator that is coupled to an electronic quantum dot junction. Famous examples of NEMS are suspended carbon nanotube (CNT) resonators, which

• of the electronic chemical potentials in the leads provides the bias voltage Vbias applied to the junction: μL = μ + eVbias/2, μR = μ − eVbias/2, with μ being the average chemical potential. The left and right leads will be considered as thermostats in equilibrium at the temperatures TL = T + ΔT/2

• molecular junction will be analyzed. In Equation 6, the coupling between the displacement and a phonon q in the lead α is given by the elastic constant Cq,α. In order to characterize this interaction, one introduces the spectral density J(ω): with M being the mass of the lead atoms and the frequency

Invariance of molecular charge transport upon changes of extended molecule size and several related issues

• Ioan Bâldea

Beilstein J. Nanotechnol. 2016, 7, 418–431, doi:10.3762/bjnano.7.37

• , characterizing the molecule–electrode couplings (x = L,R). Within the Landauer approach, which provides a general framework to describe the molecular transport within the elastic, uncorrelated transport approximation, the (steady-state) current I through a molecular junction is obtained by integrating the

• molecular junction considered below, which is schematically depicted in Figure 1, reads In the equations above, al (), br (), and cμ () stand for annihilation (creation) operators for electrons in the left and right electrodes and in the “small” molecule, respectively. Restricting to spin-independent

• organic molecules. For concrete cases, the model parameters (Hμ,μ′, τL,R, tL,R) can be obtained within density-functional-based, tight binding (DFTB) frameworks [18][19][20], which represent the state-of-the-art for such larger systems. In a biased junction, they may also nontrivially depend on V and, if

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

• molecular electronic devices. At present, the field of molecular electronic is far from maturity. The influence of the junction geometry on the electrical characteristics of single molecules remains a fascinating and important area of research. Early experiments have shown that the electrical

• electrical properties [20]. Moreover, transistor-type devices from the same molecule have displayed fundamentally different transport characteristics [21][22]. The organization of the molecules within the junction is usually based on some sort of self-assembly using chemisorption or physisorption methods to

• form monomolecular layers between both electrodes. In many cases, either self-assembled monolayers (SAMs) [23] or Langmuir–Blodgett films (LB) [24][25] of organic molecules on a solid surface provide the order at the molecular level inside the junction to accomplish interface functionalization. The

Synthesis and applications of carbon nanomaterials for energy generation and storage

• Marco Notarianni,
• Jinzhang Liu,
• Kristy Vernon and
• Nunzio Motta

Beilstein J. Nanotechnol. 2016, 7, 149–196, doi:10.3762/bjnano.7.17

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

• possibility of electronic components that are smaller than existing transistors or diodes, have unusual properties not possible with conventional semiconductors, use less power, or are cheaper than existing microelectronics. A basic element of Molecular Electronics is the “molecular junction (MJ)” consisting

• of molecules oriented between two conductors, with charge transport through the molecular layer. The vast majority of existing junction structures are based on metal/molecule bonding such as the Au/thiol self-assembled monolayers [13][14][15][16][17][18][19][20][21], Langmuir–Blodgett films on metals

Large area scanning probe microscope in ultra-high vacuum demonstrated for electrostatic force measurements on high-voltage devices

• Urs Gysin,
• Thilo Glatzel,
• Thomas Schmölzer,
• Adolf Schöner,
• Sergey Reshanov,
• Holger Bartolf and
• Ernst Meyer

Beilstein J. Nanotechnol. 2015, 6, 2485–2497, doi:10.3762/bjnano.6.258

• the benefit of surface photo voltage measurements, we analysed the contact potential difference of a silicon carbide p/n-junction under illumination. Keywords: copper alloy; electrostatic force microscopy; high-voltage device; Kelvin probe force microscopy; silicon carbide (SiC); surface photo

• SiC structure of a power semiconductor device is observed by means of large area KPFM measurements. The structure is a junction barrier Schottky (JBS) rectifier-architecture [26]. We observe the termination region of the device, where highly doped p+-rings are embedded into a large p-type ring. These

• the generated electron–hole pairs are reducing the surface band bending depending on the illumination intensity and energy even until flat-band conditions. To demonstrate the impact of SPV, we illuminated the SiC p/n-junction with laser light of 470–480 nm and a power of maximum 50 mW. An increase of

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

• tunneling spectroscopy (IETS). The molecule is contacted with gold nano-electrodes formed with the mechanically controllable break junction technique. We record the IETS spectrum of the molecule from direct current measurements, both as a function of time and electrode separation. We find that for fixed

• electrode separation the molecule switches between various configurations, which are characterized by different IETS spectra. Similar variations in the IETS signal are observed during atomic rearrangements upon stretching of the molecular junction. Using quantum chemistry calculations, we identity some of

• 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

Effects of spin–orbit coupling and many-body correlations in STM transport through copper phthalocyanine

• Benjamin Siegert,
• Andrea Donarini and
• Milena Grifoni

Beilstein J. Nanotechnol. 2015, 6, 2452–2462, doi:10.3762/bjnano.6.254

• model, the bias voltage at which a tip-mediated transition from the m-th neutral state to the n-th anionic state of the molecule is happening is where e is the electron charge and αT accounts for the fact that in STM setups the bias voltage drops asymmetrically across the junction. Electrostatic

• molecular systems with orbital degeneracies have been derived for example in carbon nanotubes [31]. In order to study fingerprints of the SOI under realistic experimental conditions, we have studied the magnetotransport characteristics of a CuPc based junction in an STM setup. To this extent, a generalized

High electronic couplings of single mesitylene molecular junctions

• Yuki Komoto,
• Shintaro Fujii,
• Tomoaki Nishino and
• Manabu Kiguchi

Beilstein J. Nanotechnol. 2015, 6, 2431–2437, doi:10.3762/bjnano.6.251

• transport properties of single mesitylene (1,3,5-trimethylbenzene) molecular junctions. The electronic conductance and the current–voltage characteristics of mesitylene molecules wired into Au electrodes were measured by a scanning tunnelling microscopy-based break-junction method at room temperature in a

• electrode perpendicular to the charge transport direction and (ii) mesitylene has tilted from the perpendicular orientation. Keywords: break junction; charge transport; mesitylene; single molecular junction; scanning tunnelling microscopy (STM); Introduction Along with increasing interests in molecular

• electronics on the single molecular scale [1], much efforts have been devoted to understand charge transport in a single molecular junction, in which a single molecule is wired to two metal electrodes. In recent years single molecular junctions with electronic functionalities such as diodes [2][3][4][5][6][7