Seebeck coefficient of silicon nanowire forests doped by thermal diffusion

• Shaimaa Elyamny,
• Elisabetta Dimaggio and
• Giovanni Pennelli

Beilstein J. Nanotechnol. 2020, 11, 1707–1713, doi:10.3762/bjnano.11.153

• (conductance Gi = 1/Ri). It is straightforward to obtain . Taking into account the distributed parameters we derive the formula above. The simulations yield (as absolute values) S = 0.448 mV/K for the nanowires doped at 700 °C for 10 min, and S = 0.207 mV/K for the nanowires doped at 800 °C for 10 min. This

Selective detection of complex gas mixtures using point contacts: concept, method and tools

• Alexander P. Pospelov,
• Victor I. Belan,
• Dmytro O. Harbuz,
• Volodymyr L. Vakula,
• Lyudmila V. Kamarchuk,
• Yuliya V. Volkova and
• Gennadii V. Kamarchuk

Beilstein J. Nanotechnol. 2020, 11, 1631–1643, doi:10.3762/bjnano.11.146

• 10.3762/bjnano.11.146 Abstract Of all modern nanosensors using the principle of measuring variations in electric conductance, point-contact sensors stand out in having a number of original sensor properties not manifested by their analogues. The nontrivial nature of point-contact sensors is based on the

• unique properties of Yanson point contacts used as the sensing elements. The quantum properties of Yanson point contacts enable the solution of some of the problems that could not be solved using conventional sensors measuring conductance. In the present paper, we demonstrate this by showing the

• point contacts as the basic element of quantum sensor devices [3][4]. Of all modern nanosensors measuring a variation in electrical conductance, point-contact sensors have a number of unique properties. The nontrivial nature of point-contact sensors is based on the distinctive properties of the Yanson

Self-assembly and spectroscopic fingerprints of photoactive pyrenyl tectons on hBN/Cu(111)

• Domenik M. Zimmermann,
• Knud Seufert,
• Luka Ðorđević,
• Tobias Hoh,
• Sushobhan Joshi,
• Tomas Marangoni,
• Davide Bonifazi and
• Willi Auwärter

Beilstein J. Nanotechnol. 2020, 11, 1470–1483, doi:10.3762/bjnano.11.130

• ][33], decouple perylenetetracarboxylic dianhydride (PTCDA) aggregates [34], study interfacial charge transfer in binary phthalocyanine arrays [35], probe vibronic conductance in oligophenylenes [36], and control the charge state of F16CoPc [37]. Studies focusing on the preparation of coordination

• sample being held at ≈6 K using electrochemically etched W tips. In the figure captions, voltages refer to the bias voltage applied to the sample. Differential conductance (dI/dV) spectra were recorded using the lock-in technique (f = 969 Hz, Vrms= 18 mV). Reducing the tip-sample distance by increasing

One-step synthesis of carbon-supported electrocatalysts

• Sebastian Tigges,
• Nicolas Wöhrl,
• Ivan Radev,
• Ulrich Hagemann,
• Markus Heidelmann,
• Thai Binh Nguyen,
• Stanislav Gorelkov,
• Stephan Schulz and
• Axel Lorke

Beilstein J. Nanotechnol. 2020, 11, 1419–1431, doi:10.3762/bjnano.11.126

• provide not only a high surface area but also a decent electrical conductance, thus acting as an ideal support material for electrocatalysis [18][19]. The route for the simultaneous growth of both the Pt precipitates and the carbon matrix (CNWs), which merge to form the catalytic hybrid material, is

Superconductor–insulator transition in capacitively coupled superconducting nanowires

• Alex Latyshev,
• Andrew G. Semenov and
• Andrei D. Zaikin

Beilstein J. Nanotechnol. 2020, 11, 1402–1408, doi:10.3762/bjnano.11.124

• slips. The corresponding contribution to the total Hamiltonian for our system can be expressed in the form [14] where denotes the QPS amplitudes per unit wire length [6], gjξ = Rq/Rjξ is the dimensionless conductance of the jth wire segment of length equal to the superconducting coherence length ξ (here

Atomic defect classification of the H–Si(100) surface through multi-mode scanning probe microscopy

• Jeremiah Croshaw,
• Thomas Dienel,
• Taleana Huff and
• Robert Wolkow

Beilstein J. Nanotechnol. 2020, 11, 1346–1360, doi:10.3762/bjnano.11.119

• ]. Individual atoms within each dimer are clearly visible, with minimal conductance occurring directly through the bulk states (requiring a reduction in tip–sample separation). This imaging mode is useful for cases where excessive bulk current could mask more subtle features. For all constant height modes, the

Effect of localized helium ion irradiation on the performance of synthetic monolayer MoS₂ field-effect transistors

• Jakub Jadwiszczak,
• Pierce Maguire,
• Conor P. Cullen,
• Georg S. Duesberg and
• Hongzhou Zhang

Beilstein J. Nanotechnol. 2020, 11, 1329–1335, doi:10.3762/bjnano.11.117

• improvement of both the carrier mobility in the transistor channel and the electrical conductance of the MoS2, due to doping with ion beam-created sulfur vacancies. Larger areal irradiations introduce a higher concentration of scattering centers, hampering the electrical performance of the device. In addition

• conductance between the IR = 2% and IR = 7% irradiations, followed by a continuing drop when IR > 18%. For small values of IR (blue curves in Figure 2b), the FET experiences a large Vth shift (Δ > 10 V) to negative gate biases, a lowered on/off ratio (approx. 102), and an increased conductance relative to the

• untreated device. As IR is increased into the green (28–41%) and red (48–76%) groups, the device conductance drops heavily, accompanied by positive-bias Vth shifts, while the on/off ratio is also seen to decrease roughly exponentially. This is demonstrated in Figure 2c, which tracks the log-transformed on

Role of redox-active axial ligands of metal porphyrins adsorbed at solid–liquid interfaces in a liquid-STM setup

• Thomas Habets,
• Sylvia Speller and
• Johannes A. A. W. Elemans

Beilstein J. Nanotechnol. 2020, 11, 1264–1271, doi:10.3762/bjnano.11.110

• conductance would be expected with an increasing distance between the tip and sample [14], which again was not observed for solutions of MnTUPCl. The variations in the additional current did not increase when the tip–sample separation distance was varied between 5 and 20 µm (20 µm was the physical limit of

Scanning tunneling microscopy and spectroscopy of rubrene on clean and graphene-covered metal surfaces

• Karl Rothe,
• Alexander Mehler,
• Nicolas Néel and
• Jörg Kröger

Beilstein J. Nanotechnol. 2020, 11, 1157–1167, doi:10.3762/bjnano.11.100

• -covered Ir(111) [9] have been reported so far. In these studies molecular orbitals, the highest occupied molecular orbital (HOMO) or the lowest unoccupied molecular orbital (LUMO), appear with spectroscopic fine structure in differential conductance (dI/dV, I: tunneling current, V: bias voltage) data

Monolayers of MoS₂ on Ag(111) as decoupling layers for organic molecules: resolution of electronic and vibronic states of TCNQ

• Asieh Yousofnejad,
• Gaël Reecht,
• Nils Krane,
• Christian Lotze and
• Katharina J. Franke

Beilstein J. Nanotechnol. 2020, 11, 1062–1071, doi:10.3762/bjnano.11.91

• 4.6 K. Differential conductance (dI/dV) maps and spectra were recorded with a lock-in amplifier at modulation frequencies of 812–921 Hz, with the amplitudes given in the figure captions. Characterization of single-layer MoS2 on Ag(111) Figure 1a presents an STM image of the Ag(111) surface after the

• moiré pattern bears a topographic and an electronic modulation [38], we investigate the differential conductance (dI/dV) spectra on different locations (Figure 1d). We first examine the spectrum on the top site of the moiré structure. We observe a gap in the density of states, which is flanked by an

• onset of conductance at approx. −1.55 V and approx. +0.05 V (marked by dashed lines labeled VBM or CBM, which have been determined from a logarithmically scaled plot). Additionally, there are pronounced peaks at approx. 0.77 V and approx. 1.28 V. First, we note that the observed bandgap is significantly

Effect of magnetic field, heat generation and absorption on nanofluid flow over a nonlinear stretching sheet

• Santoshi Misra and
• Govardhan Kamatam

Beilstein J. Nanotechnol. 2020, 11, 976–990, doi:10.3762/bjnano.11.82

• thermal conductivity and convective heat transfer performance of base fluids such as water, ethylene, glycol, etc. This takes place due to the intense and rigorous distribution of nanoparticle Brownian motion within the base fluid, thus enhancing the uniformity, conductance and properties which have paved

A Josephson junction based on a highly disordered superconductor/low-resistivity normal metal bilayer

• Pavel M. Marychev and
• Denis Yu. Vodolazov

Beilstein J. Nanotechnol. 2020, 11, 858–865, doi:10.3762/bjnano.11.71

• suppressed. It allows us to use normal-state heat conductivity both in the SN and the S region in the heat conductance equation for the calculation of δTe. This is in contrast to S-N-S and S’-S-S’ junctions where heat conductivity is suppressed in the superconducting banks. In our model Joule dissipation is

Templating effect of single-layer graphene supported by an insulating substrate on the molecular orientation of lead phthalocyanine

• K. Priya Madhuri,
• Abhay A. Sagade,
• Pralay K. Santra and
• Neena S. John

Beilstein J. Nanotechnol. 2020, 11, 814–820, doi:10.3762/bjnano.11.66

• microscopy shows enhanced vertical conductance with interconnected conducting domains consisting of ordered monoclinic crystallites through which the charge transfer occurs via tunneling. These results show the importance of a templating layer to induce the formation of a required phase of PbPc suitable for

Electromigration-induced directional steps towards the formation of single atomic Ag contacts

• Atasi Chatterjee,
• Christoph Tegenkamp and
• Herbert Pfnür

Beilstein J. Nanotechnol. 2020, 11, 680–687, doi:10.3762/bjnano.11.55

• investigated for ultrathin (5 nm) Ag structures at 100 K by measuring the conductance as a function of the time during EM. In this paper, we compare the process of thinning by EM of structures with constrictions below the average grain size of Ag layers (15 nm) with that of structures with much larger initial

• constrictions of around 150 nm having multiple grains at the centre constriction prior to the formation of a point contact. Even though clear morphological differences exist between both types of structures, quantized conductance plateaus showing the formation of single point contacts have been observed for

• both. Here we put emphasis on the thinning process by EM, just before a point contact is formed. To understand this thinning process, the semi-classical regime before the contact reaches the quantum regime was analyzed in detail. For this purpose, we used experimental conductance histograms in the

Current measurements in the intermittent-contact mode of atomic force microscopy using the Fourier method: a feasibility analysis

• Berkin Uluutku and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2020, 11, 453–465, doi:10.3762/bjnano.11.37

• collection of lock-in amplifiers [30][31]. More recently, Borgani et al. used Fourier analysis to investigate non-linear conductance in C-AFM measurements, acquiring current–voltage responses at every scan point without sacrificing scanning speed [32]. In order to explore the various phenomena involved in

• with relatively high conductance materials do exist (e.g., FEMTO DHPCA-100, trans-impedance amplifier [48]), which could, for example, record currents in the nanoampere regime at frequencies near 1 MHz. For experiments conducted on materials with significantly lower conductivity, different approaches

Nonequilibrium Kondo effect in a graphene-coupled quantum dot in the presence of a magnetic field

• Levente Máthé and
• Ioan Grosu

Beilstein J. Nanotechnol. 2020, 11, 225–239, doi:10.3762/bjnano.11.17

• does not show up in the density of states and in the differential conductance for zero chemical potential due to the linear energy dispersion of graphene. An analytical method to calculate self-energies is also developed which can be useful in the study of graphene-based systems. Conclusion: Our

• , to the right for spin-up electrons and to the left for spin-down electrons. Thus, the Kondo peaks originally located at the values of the chemical potentials are split into two new peaks. It was found that the differential conductance consists of an observable peak when the asymmetric bias voltage

• equals the Zeeman energy. In the case of finite Coulomb interaction, the zero-temperature linear conductance is suppressed under a magnetic field, and double-resonant peaks show up at high magnetic fields [26] in good agreement with the experimental measurements [30]. The approximation proposed by Meir

Nanosecond resistive switching in Ag/AgI/PtIr nanojunctions

• Botond Sánta,
• Dániel Molnár,
• Patrick Haiber,
• Agnes Gubicza,
• Edit Szilágyi,
• Zsolt Zolnai,
• András Halbritter and
• Miklós Csontos

Beilstein J. Nanotechnol. 2020, 11, 92–100, doi:10.3762/bjnano.11.9

• Nanometer-scale resistive switching devices operated in the metallic conductance regime offer ultimately scalable and widely reconfigurable hardware elements for novel in-memory and neuromorphic computing architectures. Moreover, they exhibit high operation speed at low power arising from the ease of the

• limitations: (i) Due to their self-assembled, filamentary nature, the macroscopically observable conductance features of the devices are determined by lithographically inaccessible, metallic volumes close to the atomic scale. (ii) The Fermi wavelength in these filaments falls in the regime of the interatomic

• distances granting metallic conductance also in this ultimate scaling limit. (iii) The device conductance is largely determined by the rearrangement of only a few atoms in this narrowest cross section, which can take place at a very large bandwidth and unprecedentedly low energy cost [5][6][7][8][9

First principles modeling of pure black phosphorus devices under pressure

• Ximing Rong,
• Zhizhou Yu,
• Zewen Wu,
• Junjun Li,
• Bin Wang and
• Yin Wang

Beilstein J. Nanotechnol. 2019, 10, 1943–1951, doi:10.3762/bjnano.10.190

• .10.190 Abstract Black phosphorus (BP) has a pressure-dependent bandgap width and shows the potential for applications as a low-dimensional pressure sensor. We built two kinds of pure BP devices with zigzag or armchair conformation, and explored their pressure-dependent conductance in detail by using

• first principles calculations. The zigzag BP devices and the armchair BP devices exhibit different conductance–pressure relationships. For the zigzag BP devices conductance is robust against stress when the out-of-plane pressure ratio is less than 15%, and then increases rapidly until the conductive

• channels are fully opened. For the armchair pure BP devices conductance decreases at first by six orders of magnitude under increasing pressure and then increases quickly with further increase of pressure until the devices enter the on-state. This shows that the pure zigzag BP devices are more suitable for

Remarkable electronic and optical anisotropy of layered 1T’-WTe₂ 2D materials

• Qiankun Zhang,
• Rongjie Zhang,
• Jiancui Chen,
• Wanfu Shen,
• Chunhua An,
• Xiaodong Hu,
• Mingli Dong,
• Jing Liu and
• Lianqing Zhu

Beilstein J. Nanotechnol. 2019, 10, 1745–1753, doi:10.3762/bjnano.10.170

• to understanding its structural and optical properties has been undertaken. Here we report quantitative, comprehensive work on the highly anisotropic, optical, electrical and optoelectronic properties of few-layer 1T’-WTe2 by azimuth-dependent reflectance difference microscopy, DC conductance

• measurements, as well as polarization-resolved and wavelength-dependent optoelectrical measurements. The electrical conductance anisotropic ratio is found to ≈103 for a thin 1T’-WTe2 film, while the optoelectronic anisotropic ratio is around 300 for this material. The polarization dependence of the photo

• times relative electrical anisotropy. Subsequently, the photo-electrical conductance was studied to further explore the anisotropic photo-electric property. Our results revealed an anisotropic photo-electrical conductance with a maximum ratio of 4.33 among the 12 directions. Finally, a photodetector

Kelvin probe force microscopy work function characterization of transition metal oxide crystals under ongoing reduction and oxidation

• Dominik Wrana,
• Karol Cieślik,
• Wojciech Belza,
• Christian Rodenbücher,
• Krzysztof Szot and
• Franciszek Krok

Beilstein J. Nanotechnol. 2019, 10, 1596–1607, doi:10.3762/bjnano.10.155

• nanowire edges are due to technical artefacts, such as wear of the coating of the conductive probe). To better illustrate the differences, I–V characteristics of TiO and STO were collected and are presented in Figure 2c. Given the ohmic behavior at the TiO nanowire, the conductance of the whole system (tip

High-temperature resistive gas sensors based on ZnO/SiC nanocomposites

• Vadim B. Platonov,
• Marina N. Rumyantseva,
• Alexander S. Frolov,
• Alexey D. Yapryntsev and
• Alexander M. Gaskov

Beilstein J. Nanotechnol. 2019, 10, 1537–1547, doi:10.3762/bjnano.10.151

• material conductance, kB is the Boltzmann constant, the values of the activation energy Ea were calculated. For ZnO nanofibers, Ea = 0.40 ± 0.04 eV. This value lies within the error with the potential barrier at the grain boundaries eVs (the surface potential barrier energy between particles of

• nanocrystalline zinc oxide) determined by the method of temperature-stimulated conductance measurements [29][30] as eVs = 0.44 eV at T = 500 °C [31]. The creation of ZnO/SiC nanocomposites leads to an increase in the activation energy of conductivity up to 0.71–0.78 eV, and the value of Еa does not depend on the

• nanofibers, nanocrystalline SiC and ZnO/SiC nanocomposites. X-ray photoelectron spectra of SiC in the Si 2p (a), C 1s (b), and O 1s (c) regions. X-ray photoelectron spectra of the ZnO/SiC_15 nanocomposite (a, c) and ZnO nanofibers (b, d) in the Zn 2p (a, b) and O 1s (c, d) regions. The conductance, G, of ZnO

Energy distribution in an ensemble of nanoparticles and its consequences

• Dieter Vollath

Beilstein J. Nanotechnol. 2019, 10, 1452–1457, doi:10.3762/bjnano.10.143

• , it was also applied to calculate particle size distributions from experimental data of phase transformations. As examples, the superparamagnetic transition of cobalt particles and the transition of lead particles from normal conductance to superconductivity were applied. Within the precision of the

A biomimetic nanofluidic diode based on surface-modified polymeric carbon nitride nanotubes

• Kai Xiao,
• Baris Kumru,
• Lu Chen,
• Lei Jiang,
• Bernhard V. K. J. Schmidt and
• Markus Antonietti

Beilstein J. Nanotechnol. 2019, 10, 1316–1323, doi:10.3762/bjnano.10.130

• with electron-rich –NH terminal groups. The negative surface charge is a crucial factor in ion transport. To confirm that confinement effects as well as the surface charge control the ion-transport properties [36][37][38], we measured the conductance of KCl electrolyte both in bulk solution and across

• the carbon nitride nanotubes (Figure S4, Supporting Information File 1). Figure 3 showed the conductance as a function of salt concentration (KCl) both in bulk solution and across the CNNM. The conductivity of the bulk solution is proportional to the concentration of KCl, while the ionic conductance

• , while the latter is typically assigned to impurity carbon, such as graphitic C or grease. (d) High-resolution XPS N 1s spectra that are deconvoluted into three peaks, 398.6 eV (C=N–C), 399.7 eV (N–C3), and 400.9 eV (C–NH–C and C–NH2). Conductance as a function of the salt concentration, indicating ion

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

• surfaces [13][14][15][16][17][18][19][20][21]. Low-temperature STM/STS is an ideal tool to study the Kondo effect, which manifests itself by a sharp zero-bias resonance in the conductance spectrum of a localized moment on a conducting substrate, due to the coherent spin-flip scattering between the

• in the gap of the STM is investigated by probing the differential conductance through the junction. The STS spectrum of a MnPc molecule flat-lying on Au(111) is taken with a bare metallic tip and used as a reference spectrum to be compared with the STS result obtained with a MnPc-terminated tip

• spectroscopy (IETS) close to the Fermi level. The differential conductance (dI/dV) spectrum (Figure 2e) reveals a prominent sharp peak close to the zero-bias voltage and two side peaks corresponding to step-like increases in the dI/dV signal (labeled ΔG) at threshold voltages |Vth| = 110 ± 5 meV. This is a

Glucose-derived carbon materials with tailored properties as electrocatalysts for the oxygen reduction reaction

• Rafael Gomes Morais,
• Natalia Rey-Raap,
• José Luís Figueiredo and
• Manuel Fernando Ribeiro Pereira

Beilstein J. Nanotechnol. 2019, 10, 1089–1102, doi:10.3762/bjnano.10.109

• could result in a material with higher electrical conductance, or due to the higher amount of oxygen [13]. The LSV of carbonized samples reveals that although sample CGBM presents a much higher oxygen content, CG and CGBM samples display the same onset potential (0.64 V), which suggests that the more

• positive onset potential of sample AGBM is due to its higher conductance. Moreover, samples AG and AGBM exhibit a second shoulder at more negative potentials, indicating that the ORR mechanism proceeds via the two-electron pathway producing hydrogen peroxide. This second reduction shoulder does not appear

• increases the onset potential regarding the undoped sample (CGBM) from 0.64 V to 0.67 V. Like in activated samples, this is probably due to the smaller particle size obtained after ball milling, which could result in a material with higher electrical conductance. The onset potential of sample N-AGC is