A scanning probe microscope for magnetoresistive cantilevers utilizing a nested scanner design for large-area scans

• Tobias Meier,
• Alexander Förste,
• Ali Tavassolizadeh,
• Karsten Rott,
• Dirk Meyners,
• Roland Gröger,
• Günter Reiss,
• Eckhard Quandt,
• Thomas Schimmel and
• Hendrik Hölscher

Beilstein J. Nanotechnol. 2015, 6, 451–461, doi:10.3762/bjnano.6.46

• ]. Micro-machined cantilevers on the other hand are more versatile and can be mass-produced [21]. Additionally, cantilevers produced by silicon-based microfabrication methods allow for the integration of multiple additional features such as doping for better electrical conductance or the integration of

• junction consists of two ferromagnetic CoFeB-electrodes separated by a thin dielectric MgO layer, which acts like a spin-valve. The electrical conductance of the magnetic tunnel junction, therefore, strongly depends on the orientation of the magnetization of the electrodes towards each other. When

• applied stress. In this way the TMR sensor is sensitive to both compressive and tensile stress what is required for essentially all modes of AFM. Assuming single domain behavior of the two ferromagnetic layers, the conductance of the TMR junction is depending on the angle α between the magnetizations of

Boosting the local anodic oxidation of silicon through carbon nanofiber atomic force microscopy probes

• Gemma Rius,
• Matteo Lorenzoni,
• Soichiro Matsui,
• Masaki Tanemura and
• Francesc Perez-Murano

Beilstein J. Nanotechnol. 2015, 6, 215–222, doi:10.3762/bjnano.6.20

• positively biased [9]. Typical anodic currents are of the order of nanoamperes [10] and their efficiency depends on various conditions, which concern the tip, (e.g., conductance and shape) the tip–sample interplay, (e.g., distance and wetting), and other factors such as sample surface texture or wetting. All

Gas sensing properties of nanocrystalline diamond at room temperature

• Marina Davydova,
• Pavel Kulha,
• Alexandr Laposa,
• Karel Hruska,
• Pavel Demo and
• Alexander Kromka

Beilstein J. Nanotechnol. 2014, 5, 2339–2345, doi:10.3762/bjnano.5.243

• a number of studies [14][15][16]. Overall, when oxidizing or reducing gases appear in the atmosphere, the charge exchange between the diamond and the adsorbed molecules causes an increase or a decrease in the conductance. The mechanism of this variation is broadly interpreted by the established

Spectroscopic mapping and selective electronic tuning of molecular orbitals in phosphorescent organometallic complexes – a new strategy for OLED materials

• Pascal R. Ewen,
• Jan Sanning,
• Tobias Koch,
• Nikos L. Doltsinis,
• Cristian A. Strassert and
• Daniel Wegner

Beilstein J. Nanotechnol. 2014, 5, 2248–2258, doi:10.3762/bjnano.5.234

• transferred in situ into the cold STM (T = 5 K). All images where taken in constant-current mode. For the tunneling spectra the current I and the differential conductance dI/dV (via lock-in technique, modulation voltage 10–20 mV) were measured simultaneously as a function of sample bias V under open-feedback

Electrical contacts to individual SWCNTs: A review

• Wei Liu,
• Christofer Hierold and
• Miroslav Haluska

Beilstein J. Nanotechnol. 2014, 5, 2202–2215, doi:10.3762/bjnano.5.229

• –source electrode is biased with a positive voltage and the gate electrode is set to zero voltage potential. The electrical modulation of the CNFET conductance is the consequence of the Schottky barrier width (W) modulation [23]. The shape of Schottky barrier can be modulated by the gate and drain–source

• conductance reached 0.5∙G0 (1/Rq = G0 = 154 µS) measured at room temperature. However, the strong propensity of oxidation for low work function metals cause low yield and degradation in the reproducibility of device performance. Recently, Shahrjerdi et al. [55] reported a remarkable improvement in n-type

• attached to the channels of devices (Figure 9a). Another group [73] also highlighted the importance of the annealing treatment for Au/Cr–SWCNT contacts (top contact). The on-conductance was increased by 2–3 orders of magnitude through annealing at 600 °C in Ar atmosphere [73]. It was intended that the Au

Influence of stabilising agents and pH on the size of SnO₂ nanoparticles

• Olga Rac,
• Patrycja Suchorska-Woźniak,
• Marta Fiedot and
• Helena Teterycz

Beilstein J. Nanotechnol. 2014, 5, 2192–2201, doi:10.3762/bjnano.5.228

• most widely studied and employed owing to its physicochemical properties. It features a high physicochemical stability and its electrical conductance changes predictably under the influence of various gases, which is the basis for operation of resistive gas sensors [5]. Despite the enormous number of

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

• response in Schottky barrier FETs, as the device conductance is not limited by the channel. On the other hand, in ohmic or near-ohmic contact nanotubes with extremely thin Schottky barriers (e.g., Pd-contacted nanotubes), the modulation of the conductance of the bulk channel could have a more profound

Sequence-dependent electrical response of ssDNA-decorated carbon nanotube, field-effect transistors to dopamine

• Hari Krishna Salila Vijayalal Mohan,
• Jianing An and
• Lianxi Zheng

Beilstein J. Nanotechnol. 2014, 5, 2113–2121, doi:10.3762/bjnano.5.220

• variation in transistor electrical parameters including conductance, transconductance, threshold voltage and hysteresis gap. Our results showed that the response of ssDNA-decorated devices to DA, irrespective of the presence or absence of UA, was DNA sequence dependent and exhibited the trend: G > A > C and

• sequence combinations, which interact differently with CNTs as well as DA, and consequently, this influences the FET response. The transistor electrical parameters such as conductance, transconductance, threshold voltage and hysteresis gap extracted from the current–voltage characteristics are indicators

• sensing. Electrical characterization All I–V measurements were made using a semiconductor device analyzer (Agilent, 4156B). The drain current (ID) versus gate voltage (VG) characteristics (transfer) were obtained at a drain voltage (VDS) of 1 V. The on conductance (Gon) is obtained from the slope of the

Effect of channel length on the electrical response of carbon nanotube field-effect transistors to deoxyribonucleic acid hybridization

• Hari Krishna Salila Vijayalal Mohan,
• Jianing An,
• Yani Zhang,
• Chee How Wong and
• Lianxi Zheng

Beilstein J. Nanotechnol. 2014, 5, 2081–2091, doi:10.3762/bjnano.5.217

• in electrical parameters such as conductance, transconductance, threshold voltage and hysteresis gap. The channel length (L) dependence of each of these parameters necessitates the need to include them when interpreting the effect of L on the response to hybridization. Using the definitions of

• alone. Earlier studies suggest that long SWCNTs, particularly those in the range of a few hundred micrometers, have a large coverage area, excellent normalized conductance, and extraordinary mobility at room temperature [20][21]. These properties open avenues for detecting hybridization occurring on the

• nanotube surface. However, with increasing channel length, the large channel resistance could be a limiting factor in the detection sensitivity. In particular, the FET electrical parameters such as conductance, transconductance, threshold voltage and hysteresis gap extracted from the current–voltage

Patterning a hydrogen-bonded molecular monolayer with a hand-controlled scanning probe microscope

• Matthew F. B. Green,
• Taner Esat,
• Christian Wagner,
• Philipp Leinen,
• Alexander Grötsch,
• F. Stefan Tautz and
• Ruslan Temirov

Beilstein J. Nanotechnol. 2014, 5, 1926–1932, doi:10.3762/bjnano.5.203

• that the average time necessary to remove one molecule decreased to 13 minutes after about 10 successful attempts. We stress here that this learning was based entirely on rather sparse information about the junction, namely the conductance at a fixed bias voltage and the frequency shift Δf related to

• process of gradual bond cleavage is also reflected by the initial increase in the current I(x, y, z) flowing through the junction (cf. the red sections of the successful trajectories in Figure 3a). This observation is in agreement with previously published data that relate the increase of conductance

Non-covalent and reversible functionalization of carbon nanotubes

• Antonello Di Crescenzo,
• Valeria Ettorre and
• Antonella Fontana

Beilstein J. Nanotechnol. 2014, 5, 1675–1690, doi:10.3762/bjnano.5.178

• their diameter affects the conductance, density and honeycomb lattice structure of the tube and allow to divide them in two main types, semiconducting and metallic. The CNTs chirality appears to be severely involved in the dispersion of CNTs. As an example, the chirality of the tubes drives the

The influence of molecular mobility on the properties of networks of gold nanoparticles and organic ligands

• Edwin J. Devid,
• Paulo N. Martinho,
• M. Venkata Kamalakar,
• Úna Prendergast,
• Christian Kübel,
• Tibebe Lemma,
• Jean-François Dayen,
• Tia. E. Keyes,
• Bernard Doudin,
• Mario Ruben and
• Sense Jan van der Molen

Beilstein J. Nanotechnol. 2014, 5, 1664–1674, doi:10.3762/bjnano.5.177

• the orientation and/or increased mobility of the molecules on the gold nanoparticle facets. As for their conductance, the temperature-dependence for S-BPP networks differs significantly from standard alkanethiol-capped networks, especially above 220 K. Relating the latter two observations, we propose

• for molecular conductance experiments, includes nanoparticles (ca. 10 nm) incorporated to bridge the size gap between macroscopic electrodes (larger than 100 nm) and molecules (ca. 1 nm) [2][3][4][5][6][7][8]. Typically, 2D arrays of gold nanoparticles capped by alkanethiols are created, after which

• this purpose, the fabricated 2D Au-NP–S-BPP arrays are electrically contacted to lithographically defined devices [5][8][9][12] and the obtained conductance measurements are compared to benchmark networks formed with alkanethiols spacers. Experimental Capping of gold nanoparticles with S-BPP molecules

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

• two contacts leading to a current flow across the surface. Thus, if the main contribution of the total current is flowing through the Au reconstructed 1D domains, the impact of the predicted conductance anisotropy should be observed as a variation of the electrochemical potential in the vicinity of

Review of nanostructured devices for thermoelectric applications

• Giovanni Pennelli

Beilstein J. Nanotechnol. 2014, 5, 1268–1284, doi:10.3762/bjnano.5.141

• /∂x = εJ, it is possible to determine T(x) in the legs, and also ΦH and ΦC, so that an expression for the efficiency η can be obtained: where Rg and K are the total electrical resistance and the total thermal conductance of the generator, which can be evaluated respectively from the material

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

• enhanced when dopants are placed on one sublattice, compared to a random distribution, and that a band gap does indeed open. The difference in transport qualities between the asymmetrically doped versus completely randomly doped systems is illustrated by a conductance plot in Figure 4, where it is evident

• that the electrons in the former kind of device will be subjected to less scattering leading to an increase in the quantum conductance, closer to that of the pristine system when subjected to a positive bias. It should also be noted that that symmetry breaking in nanoribbons occurs via edge effects and

• dashed line shows the expected band gap scaling with concentration, according to the power 3/4 as discussed in the text. Quantum conductance through a 15 nm wide graphene nanoribbon with a 7.5 nm long scattering region containing a dispersion of substitutional nitrogen impurities, in a similar vein to

Organic and inorganic–organic thin film structures by molecular layer deposition: A review

• Pia Sundberg and
• Maarit Karppinen

Beilstein J. Nanotechnol. 2014, 5, 1104–1136, doi:10.3762/bjnano.5.123

Methods for rapid frequency-domain characterization of leakage currents in silicon nanowire-based field-effect transistors

• Tomi Roinila,
• Xiao Yu,
• Jarmo Verho,
• Tie Li,
• Pasi Kallio,
• Matti Vilkko,
• Anran Gao and
• Yuelin Wang

Beilstein J. Nanotechnol. 2014, 5, 964–972, doi:10.3762/bjnano.5.110

• 10.3762/bjnano.5.110 Abstract Silicon nanowire-based field-effect transistors (SiNW FETs) have demonstrated the ability of ultrasensitive detection of a wide range of biological and chemical targets. The detection is based on the variation of the conductance of a nanowire channel, which is caused by the

Integration of ZnO and CuO nanowires into a thermoelectric module

• Dario Zappa,
• Simone Dalola,
• Guido Faglia,
• Elisabetta Comini,
• Matteo Ferroni,
• Caterina Soldano,
• Vittorio Ferrari and
• Giorgio Sberveglieri

Beilstein J. Nanotechnol. 2014, 5, 927–936, doi:10.3762/bjnano.5.106

• conductance comes from the electrical conductivity along the axis of the nanowires. As-grown nanowires do not show any particular alignment respect to the substrate surface, as a result of combined growth mechanism and mechanical stress. Some degree of vertical alignment would not have improved the overall

An analytical approach to evaluate the performance of graphene and carbon nanotubes for NH₃ gas sensor applications

• Elnaz Akbari,
• Vijay K. Arora,
• Aria Enzevaee,
• Mohamad. T. Ahmadi,
• Mehdi Saeidmanesh,
• Mohsen Khaledian,
• Hediyeh Karimi and
• Rubiyah Yusof

Beilstein J. Nanotechnol. 2014, 5, 726–734, doi:10.3762/bjnano.5.85

• structure of these allotropes. A mathematical model is proposed with a clear purpose to acquire an analytical understanding of the field-effect-transistor (FET) based gas detection mechanism. The conductance change in the CNT/graphene channel resulting from the chemical reaction between the gas and channel

• compared with the experimental data. A satisfactory agreement, within the uncertainties of the experiments, is obtained. Graphene-based gas sensor exhibits higher conductivity compared to that of CNT-based counterpart for similar ambient conditions. Keywords: carbon nanotube (CNT); conductance; FET-based

• and its applications to quantum transport. In a recent paper [14], Chin et. al show how nanoelectronic parameters can be extracted from quantum conductance. In the next section, we advance these thoughts as we design the sensor made out of graphene and CNT. Carbon nanotubes and graphene CNTs were

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

• 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

• oxygen atoms and is moved further towards the surface until a sudden increase in junction conductance and change in Δf occurs (cf. Figure 1a). The conductance increases due to the snap-up of the oxygen atom to the tip, which marks the formation of a chemical tip–molecule bond [23]. Once the contact to

Charge and spin transport in mesoscopic superconductors

• M. J. Wolf,
• F. Hübler,
• S. Kolenda and
• D. Beckmann

Beilstein J. Nanotechnol. 2014, 5, 180–185, doi:10.3762/bjnano.5.18

• and 1980s, mostly in the vicinity of the critical temperature. Much less attention has been paid to low temperatures and the role of the quasiparticle spin. Results: We report here on nonlocal transport in superconductor hybrid structures at very low temperatures. By comparing the nonlocal conductance

• current Iinj flowing into the junction is measured to determine the local differential conductance gloc = dIinj/dVinj. Simultaneously, the current Idet flowing out of a nearby detector junction is measured to obtain the nonlocal conductance gnl = dIdet/dVinj. The nonlocal conductance was measured for

• , the effect of the applied field is mostly orbital pair breaking, and the Zeeman splitting of the density of states does not play a significant role. In Figure 2a, we show the nonlocal conductance gnl of a pair of contacts at low temperature and for bias voltages above the energy gap Δ ≈ 200 μeV of the

Many-body effects in semiconducting single-wall silicon nanotubes

• Wei Wei and
• Timo Jacob

Beilstein J. Nanotechnol. 2014, 5, 19–25, doi:10.3762/bjnano.5.2

• band structures show direct band gaps of 0.28 and 0.05 eV (50 meV), respectively. In (10,0) SiNT, the vanishingly narrow gap appears at the Γ point. However, there are still controversies with respect to the dependence of the conductance (semiconducting or metallic) on the chirality and/or diameter of

STM tip-assisted engineering of molecular nanostructures: PTCDA islands on Ge(001):H surfaces

• Amir A. Ahmad Zebari,
• Marek Kolmer and
• Jakub S. Prauzner-Bechcicki

Beilstein J. Nanotechnol. 2013, 4, 927–932, doi:10.3762/bjnano.4.104

• . The differential tunneling conductance (dI/dV) as a function of the sample bias V was obtained numerically from the I–V curves. (a) High resolution STM image on top of a PTCDA island, 25 nm × 25 nm, showing the herringbone structure. (b) STS curves for Ge(001), Ge(001):H and PTCDA molecular island. (c

In situ growth optimization in focused electron-beam induced deposition

• Paul M. Weirich,
• Marcel Winhold,
• Christian H. Schwalb and
• Michael Huth

Beilstein J. Nanotechnol. 2013, 4, 919–926, doi:10.3762/bjnano.4.103

• nanostructures that are prepared by focused electron-beam-induced deposition (FEBID). It allows us to tune the properties of the deposits towards the highest conductivity by using the time gradient of the measured in situ rate of change of conductance as the fitness parameter for the algorithm. The effectiveness

• state of the metal are also important but a-priori unknown quantities [4][8]. From this, one can conclude that the optimization of any FEBID process towards the largest possible conductivity should ideally monitor the conductance as the growth proceeds [10] and use this information in adaptively

• measured in situ conductance as a fitness parameter for the GA we are able to tune the properties of the deposits towards highest conductivity. In order to demonstrate the efficiency of this method, we chose W(CO)6. Our study reveals that an increase of conductivity by one order of magnitude can be

Evolution of microstructure and related optical properties of ZnO grown by atomic layer deposition

• Adib Abou Chaaya,
• Roman Viter,
• Mikhael Bechelany,
• Zanda Alute,
• Donats Erts,
• Anastasiya Zalesskaya,
• Kristaps Kovalevskis,
• Vincent Rouessac,
• Valentyn Smyntyna and
• Philippe Miele

Beilstein J. Nanotechnol. 2013, 4, 690–698, doi:10.3762/bjnano.4.78

• the band edge is an exponential function of the photon energy as described by the Urbach law [37]: where E0 is the Urbach energy interpreted as the width of the tail of the states localized close to the conductance band in the forbidden zone. Numerical calculations show a decrease of the Urbach energy