Nanostructured materials characterized by scanning photoelectron spectromicroscopy

• Matteo Amati,
• Alexey S. Shkvarin,
• Alexander I. Merentsov,
• Alexander N. Titov,
• María Taeño,
• David Maestre,
• Sarah R. McKibbin,
• Zygmunt Milosz,
• Ana Cremades,
• Rainer Timm and
• Luca Gregoratti

Beilstein J. Nanotechnol. 2025, 16, 700–710, doi:10.3762/bjnano.16.54

• expensive III–V materials to the active device area. The flexible geometry of nanowires standing upright on their growth substrate directly leads to gate-all-around metal-oxide-semiconductor stacks [23][24], and advanced electronic device designs such as nanowire tunneling field-effect transistors [24] or

Nanoscale capacitance spectroscopy based on multifrequency electrostatic force microscopy

• Pascal N. Rohrbeck,
• Lukas D. Cavar,
• Franjo Weber,
• Peter G. Reichel,
• Mara Niebling and
• Stefan A. L. Weber

Beilstein J. Nanotechnol. 2025, 16, 637–651, doi:10.3762/bjnano.16.49

• features. Scanning probe techniques have revolutionized nanoscale material characterization. Since the invention of scanning tunneling microscopy (STM) [16] and atomic force microscopy (AFM) [17], various electric force-based methods, called electrostatic force microscopy (EFM) methods, have emerged to

Functionalized gold nanoflowers on carbon screen-printed electrodes: an electrochemical platform for biosensing hemagglutinin protein of influenza A H1N1 virus

• Carlos Enrique Torres-Méndez,
• Sharmilee Nandi,
• Klara Martinovic,
• Patrizia Kühne,
• Yifan Liu,
• Sam Taylor,
• Maria Lysandrou,
• Maria Ines Berrojo Romeyro Mascarenhas,
• Viktoria Langwallner,
• Javier Enrique Sebastián Alonso,
• Ivana Jovanovic,
• Maike Lüftner,
• Georgia-Vasiliki Gkountana,
• David Bern,
• Abdul-Raouf Atif,
• Ehsan Manouchehri Doulabi,
• Gemma Mestres and
• Masood Kamali-Moghaddam

Beilstein J. Nanotechnol. 2025, 16, 540–550, doi:10.3762/bjnano.16.42

• was amplified by functionalization of the gold nanoflowers with 4-aminothiophenol, which resulted in a 100-fold decrease of the charge transfer resistance due to a tunneling effect. Subsequently, monoclonal antibodies against H1 were immobilized on the surface via covalent amide bond formation

• increased. This effect is known as tunneling charge transfer enhancement and significantly improved the sensitivity of the biosensor. It can be attributed to electron transfer through bonds due to the small length (0.59 nm) and the delocalized π-electron system of the 4-ATP linker molecule. Interestingly

• the concentration range from 10 to 10 000 pg/mL. The experimental EIS data suggest that the electron transfer on the electrode was enhanced by a factor of 100 due to the increase in surface area and to a tunneling charge transfer effect. This improvement is attributed to the synergistic effect of the

ReactorAFM/STM – dynamic reactions on surfaces at elevated temperature and atmospheric pressure

• Tycho Roorda,
• Hamed Achour,
• Matthijs A. van Spronsen,
• Marta E. Cañas-Ventura,
• Sander B. Roobol,
• Willem Onderwaater,
• Mirthe Bergman,
• Peter van der Tuijn,
• Gertjan van Baarle,
• Johan W. Bakker,
• Joost W. M. Frenken and
• Irene M. N. Groot

Beilstein J. Nanotechnol. 2025, 16, 397–406, doi:10.3762/bjnano.16.30

• , capable of studying materials under industrially relevant conditions. Here we show current developments of the ReactorAFM/STM, implementing a qPlus sensor to add the ability of combining atomic force microscopy (AFM) and scanning tunneling microscopy (STM) techniques to study the geometric and electronic

• , a high-pressure ReactorSTM has been developed [10][11]. The pressures in the scanning tunneling microscopy (STM) reactor are orders of magnitude above UHV (up to several bar), rendering gas–catalyst interactions very significant and leading to differences in reaction mechanisms [12][13][14][15

• the electric tunneling effect, AFM probes the forces of the tip–sample interaction. This makes AFM independent of surface conductivity and therefore a powerful tool to bridge the materials gap. The drawback of this high-pressure AFM setup is that it could not be combined with STM. While STM provides

Bolometric IR photoresponse based on a 3D micro-nano integrated CNT architecture

• Yasameen Al-Mafrachi,
• Sandeep Yadav,
• Sascha Preu,
• Jörg J. Schneider and
• Oktay Yilmazoglu

Beilstein J. Nanotechnol. 2024, 15, 1030–1040, doi:10.3762/bjnano.15.84

• material. The electrical conductivity of a vertically aligned CNT structure is defined by the intrinsic conductivity along the CNTs and the tunneling at the CNT junctions. The vertical electrical conduction is based on long conduction paths along the CNTs and few junction contacts, while the lateral

Recent progress on field-effect transistor-based biosensors: device perspective

• Billel Smaani,
• Fares Nafa,
• Mohamed Salah Benlatrech,
• Ismahan Mahdi,
• Hamza Akroum,
• Mohamed walid Azizi,
• Khaled Harrar and
• Sayan Kanungo

Beilstein J. Nanotechnol. 2024, 15, 977–994, doi:10.3762/bjnano.15.80

• -band tunneling of carriers. Additionally, an extended gate architecture was incorporated to attain good stability of the biomolecules at the nanocavity, significantly improving on-current sensitivity (7.96 × 109) compared to available FET-based biosensors and existing tunnel FET-biosensor structures

• change in the N+-pocket region, from the perspective of biomolecule detection, is reported. It has been demonstrated that SiGe source TFET has a significant advantage over N+-pocket TFET biosensors in terms of subthreshold current and sensitivity. 2.2.20 Schottky tunneling source impact-ionization-based

• biosensors. Singh et al. [123] reported a concept of a nanogap-embedded Schottky tunneling source impact-ionization (ST SII) FET-based biosensor with highly sensitive detection of different neutral and charged biomolecules. Figure 20 shows the architecture of ST SII FET-based biosensors. In this structure

Reduced subthreshold swing in a vertical tunnel FET using a low-work-function live metal strip and a low-k material at the drain

• Kalai Selvi Kanagarajan and
• Dhanalakshmi Krishnan Sadhasivan

Beilstein J. Nanotechnol. 2024, 15, 713–718, doi:10.3762/bjnano.15.59

• is greater. Thermionic emission affects the off-to-on transition. A small subthreshold swing is needed to turn the device to an off-state sharply, once Vgs drops below the threshold voltage (VT). Tunnel field-effect transistors (TFETs) work based on band-to-band tunneling and not on conventional

• thermionic emission as the carrier injection mechanism [3]. Band-to-band tunneling enables TFETs to have SS < 60 mV/dec [4][5][6][7]. The gate-to-drain capacitance (Cgd) effect (Miller capacitance effect) has an impact on TFET performance. Unwanted effects such as overshoot/undershoot in the inverter

• previously published model, the proposed design uses a low-k material in the drain region to reduce Cgd. A metal strip with low work function placed at the source–channel interface causes an abrupt change in electron concentration, increasing the tunneling rate [14][15][16][17][18]. Molybdenum, used here as

Stiffness calibration of qPlus sensors at low temperature through thermal noise measurements

• Laurent Nony,
• Sylvain Clair,
• Daniel Uehli,
• Aitziber Herrero,
• Jean-Marc Themlin,
• Andrea Campos,
• Franck Para,
• Alessandro Pioda and
• Christian Loppacher

Beilstein J. Nanotechnol. 2024, 15, 580–602, doi:10.3762/bjnano.15.50

• , which forms the tip. The tip is electrically connected to an electrode that collects the tunneling current if scanning tunneling experiments are to be performed along with nc-AFM experiments. The qPlus sensors feature a resonance frequency of f1 ≃ 25 kHz and a most commonly reported stiffness of 1800 N

• electrode is for grounding. The two thinner ones, running along the free prong, are for the piezoelectric current and tunneling current readouts. The free prong is l = (2045 ± 100) μm long. The tip, indicated at the end of the free prong, consists of a W wire that is 50 μm in diameter, better visible in

• , coarse motor, and bias). The tunneling current readout is also grounded. It is also made sure that no parasitic external noise source (mechanical or electrical) adds to the measurement. The measurement noise PSD ((f)) is recorded under similar conditions, except that the input of the charge amplifier is

Directed growth of quinacridone chains on the vicinal Ag(35 1 1) surface

• Niklas Humberg,
• Lukas Grönwoldt and
• Moritz Sokolowski

Beilstein J. Nanotechnol. 2024, 15, 556–568, doi:10.3762/bjnano.15.48

• the vicinal Ag(35 1 1) surface was investigated by scanning tunneling microscopy and low-energy electron diffraction. The focus was on the influence of the steps on the QA structures and their preferential azimuthal orientations with the aim of achieving a selective orientation. After deposition at a

• with a base pressure of 2 × 10−10 mbar equipped with a beetle-type scanning tunneling microscope (STM, type UHV 300) from RHK Technology, a microchannel plate low-energy diffraction (MCP-LEED) instrument from OCI Vacuum Microenginneering Inc., and a quadrupole mass spectrometer (QMS) of the type PRISMA

• . The bias voltage (UBias) refers to the sample, and the tunneling current (I) was at a constant value in the range of 10–50 pA. We usually adjusted the scanning plane parallel to the (35 1 1) plane of our sample in order to optimize the contrast of the images. The images were processed with the program

Superconducting spin valve effect in Co/Pb/Co heterostructures with insulating interlayers

• Andrey A. Kamashev,
• Nadir N. Garif’yanov,
• Aidar A. Validov,
• Vladislav Kataev,
• Alexander S. Osin,
• Yakov V. Fominov and
• Ilgiz A. Garifullin

Beilstein J. Nanotechnol. 2024, 15, 457–464, doi:10.3762/bjnano.15.41

• to plot the theoretical curve for (dPb). The value of γ is consistent with the values of ξS and ξF. What is unexpected in the above fitting parameters is a rather small value of the interface resistance parameter, γb = 0.48. In the tunneling limit, one can estimate in terms of the effective

• suppressed). The obtained small value of γb points at small thicknesses of the tunneling barriers in our junctions. Note that this correlates with observations by Deutscher and Meunier [40], who concluded that according to the resistance measurements, the barriers in their experiment were “much thinner than

• in a conventional tunneling junction”. While the theory [50] assumes a symmetric F1/S/F2 structure, our samples may actually be asymmetric from the point of view of the interface transparencies. The oxidation times of the two interfaces were different in our samples, and our fabrication procedure was

Unveiling the nature of atomic defects in graphene on a metal surface

• Karl Rothe,
• Nicolas Néel and
• Jörg Kröger

Beilstein J. Nanotechnol. 2024, 15, 416–425, doi:10.3762/bjnano.15.37

• Karl Rothe Nicolas Neel Jorg Kroger Institut für Physik, Technische Universität Ilmenau, D-98693 Ilmenau, Germany 10.3762/bjnano.15.37 Abstract Low-energy argon ion bombardment of graphene on Ir(111) induces atomic-scale defects at the surface. Using a scanning tunneling microscope, the two

• ; scanning tunneling microscopy and spectroscopy; Introduction Defects in lattices of two-dimensional (2D) materials are considered as promising building blocks for tailoring electronic and phononic band structures, magnetic texture, photon emission, and charge carrier concentration [1]. In addition

• by noble-gas ion irradiation [6][13][14][17][19][21][24], represents an opportunity for systematic defect studies. The work presented here was stimulated by the lack of experimental data on the actual geometry of atomic-scale defects in graphene. So far, scanning tunneling microscope (STM

On the mechanism of piezoresistance in nanocrystalline graphite

• Sandeep Kumar,
• Simone Dehm and
• Ralph Krupke

Beilstein J. Nanotechnol. 2024, 15, 376–384, doi:10.3762/bjnano.15.34

• values. For larger strains, mechanisms such as grain rotation and the formation of nanocracks might contribute to the piezoresistive behavior in nanocrystalline graphene. Keywords: grain boundary; nanocrystalline graphene; strain sensor; Raman; tunneling and destruction; Introduction Flexible strain

• graphene, it is still unclear which factors influence this property. A theoretical work by Kumar et al. suggested that grain boundaries can affect piezoresistance in graphene [9]. This result seemed unexpected since Dirac particles should undergo Klein tunneling at barriers without adding up to the total

• strain within the grains remains constant even though the externally applied strain increased to ca. 0.4%. In an attempt to model piezoresistance in NCG, we have used the tunneling + destruction model for composite materials [24]: The model with five free parameters was fitted to the data as shown in

Ultrasensitive and ultrastretchable metal crack strain sensor based on helical polydimethylsiloxane

• Shangbi Chen,
• Dewen Liu,
• Weiwei Chen,
• Huajiang Chen,
• Jiawei Li and
• Jinfang Wang

Beilstein J. Nanotechnol. 2024, 15, 270–278, doi:10.3762/bjnano.15.25

• formation under stretching. The sensors with helix indices C1, C2, and C3 exhibited distinct turning points at 250%, 550%, and 850% strain, respectively. The dominance of strain in the sensing mechanism can be attributed to the tunneling effect [37]. As the Au film is stretched, it gradually separates

• , resulting in an increased distance between adjacent cracks. During this stage, the resistance is primarily influenced by the coupling of tunneling resistance with the physical distance between channel cracks. Therefore, the change in resistance, corresponding to the average width of the cracks and the

• strain, can be described by the following formula: When the strain ε is small, we can formulate: where X is the tunneling barrier height-dependent function. Figure 2b shows the good linearity between measured resistance and strain; the curves fit quite well to the analytical solution. When the helical

Design, fabrication, and characterization of kinetic-inductive force sensors for scanning probe applications

• August K. Roos,
• Ermes Scarano,
• Elisabet K. Arvidsson,
• Erik Holmgren and
• David B. Haviland

Beilstein J. Nanotechnol. 2024, 15, 242–255, doi:10.3762/bjnano.15.23

• strip to connect the base of the cone to the Nb-Ti-N film, which is the ground plane of the microwave circuit. This feature enables the measurement of the tunneling current between the tip (grounded) when a DC bias is applied to a conductive sample surface. Scanning tunneling microscopy (STM) operation

Exploring disorder correlations in superconducting systems: spectroscopic insights and matrix element effects

• Vyacheslav D. Neverov,
• Alexander E. Lukyanov,
• Andrey V. Krasavin,
• Alexei Vagov,
• Boris G. Lvov and
• Mihail D. Croitoru

Beilstein J. Nanotechnol. 2024, 15, 199–206, doi:10.3762/bjnano.15.19

• previously reported in [47]. This work focuses on a different aspect of the influence of the disorder correlations, investigating how the latter affect key spectral characteristics of a superconductor, that is, the energy level distribution. Recent scanning tunneling spectroscopy experiments on highly

• to model the s-wave Cooper pairing [51][52], Here, the particle number operators at site i are expressed through the electron operators with spin σ. The tunneling amplitude tij = −t is assumed nonzero only for the nearest sites, μ denotes the chemical potential, Vi is the disorder potential, and g

Josephson dynamics and Shapiro steps at high transmissions: current bias regime

• Artem V. Galaktionov and
• Andrei D. Zaikin

Beilstein J. Nanotechnol. 2024, 15, 51–56, doi:10.3762/bjnano.15.5

• T → 0 can flow across the junction. The situation becomes entirely different provided one goes beyond the tunneling limit and considers highly transparent superconducting weak links in which case the charge transfer is essentially controlled by the mechanism of multiple Andreev reflection [2]. This

Measurements of dichroic bow-tie antenna arrays with integrated cold-electron bolometers using YBCO oscillators

• Leonid S. Revin,
• Dmitry A. Pimanov,
• Alexander V. Chiginev,
• Anton V. Blagodatkin,
• Viktor O. Zbrozhek,
• Andrey V. Samartsev,
• Anastasia N. Orlova,
• Dmitry V. Masterov,
• Alexey E. Parafin,
• Victoria Yu. Safonova,
• Anna V. Gordeeva,
• Andrey L. Pankratov,
• Leonid S. Kuzmin,
• Anatolie S. Sidorenko,
• Silvia Masi and
• Paolo de Bernardis

Beilstein J. Nanotechnol. 2024, 15, 26–36, doi:10.3762/bjnano.15.3

• system resistance; also, the total noise is decreased. The SN contact should, in turn, accelerate the tunneling of hot electrons from the absorber, serving as an open gate. In the course of measurements of the obtained samples, however, it turned out that the resistance of the obtained samples was higher

Spatial variations of conductivity of self-assembled monolayers of dodecanethiol on Au/mica and Au/Si substrates

• Julian Skolaut,
• Jędrzej Tepper,
• Federica Galli,
• Wulf Wulfhekel and
• Jan M. van Ruitenbeek

Beilstein J. Nanotechnol. 2023, 14, 1169–1177, doi:10.3762/bjnano.14.97

• current maps after DDT SAM formation. The presence of a well-ordered SAM on the surface was confirmed by scanning tunneling microscopy (STM) images on alkanethiol-covered Au surfaces prepared in the same way, in which the individual molecules can be resolved, shown in Figure S4 in Supporting Information

A bifunctional superconducting cell as flux qubit and neuron

• Dmitrii S. Pashin,
• Pavel V. Pikunov,
• Marina V. Bastrakova,
• Andrey E. Schegolev,
• Nikolay V. Klenov and
• Igor I. Soloviev

Beilstein J. Nanotechnol. 2023, 14, 1116–1126, doi:10.3762/bjnano.14.92

• getting closer, and the anticrossing effect is observed. For the ground and first-excited states, characteristic times of anticrossing correspond to τLZ, when the adiabatic condition (Equation 5) is violated and a non-zero probability of Landau–Zener tunneling between these energy levels emerges. As long

• ,d correspond to regions where there is a non-zero probability of quantum-coherent Landau–Zener tunneling, and black areas correspond to the adiabatic control of the system. According to the expressions in Equation 12, the white dashed line in Figure 2c denotes the limit of the transition probability

• functions [30]. We can see from Figure 2e that for the symmetric control field for given DR,F, there are ranges of inductance values l where we can control the populations of levels by external influence using the Landau–Zener tunneling effect. In other words, in this parameter range we can, if necessary

Two-dimensional molecular networks at the solid/liquid interface and the role of alkyl chains in their building blocks

• Suyi Liu,
• Yasuo Norikane and
• Yoshihiro Kikkawa

Beilstein J. Nanotechnol. 2023, 14, 872–892, doi:10.3762/bjnano.14.72

• and desirable nanoarchitectures. Scanning tunneling microscopy is a powerful tool for revealing the molecular conformations, arrangements, and orientations of two-dimensional (2D) networks on surfaces. The fabrication of 2D assemblies involves non-covalent interactions that play a significant role in

• this review, we focus on the role of alkyl chains in the formation of ordered 2D assemblies at the solid/liquid interface. The alkyl chain effects on the 2D assemblies are introduced together with examples documented in the past decades. Keywords: alkyl chains; scanning tunneling microscopy; self

• coordination, halogen bonding, and dispersion forces [12][13][14][15][16][17][18][19][20][21][22]. Scanning tunneling microscopy (STM) is an important tool for the direct visualization of molecular arrangements, especially for two-dimensional (2D) networks. STM observations have been performed on atomically

Current-induced mechanical torque in chiral molecular rotors

• Richard Korytár and
• Ferdinand Evers

Beilstein J. Nanotechnol. 2023, 14, 711–721, doi:10.3762/bjnano.14.57

• charge carrier and the mass of the helix per winding number. Keywords: molecular junctions; molecular motors; molecular switches; Introduction Experiments employing scanning tunneling microscopy (STM) have achieved the directed rotation of molecules controlled by an electrical current. Correspondingly

• of interest: It implies T → ∞, and, thus, a vanishing threshold Im. Directed motion of a helix with an open end Angular momentum transfer In a scanning tunneling setup, the condition in Equation 2 is not always fulfilled, for example, when the tip of the microscope does not bind to the molecule. In

• of freedom, assuming that the quantization levels of the rotational motion fall below the working temperature. Rotation only happens via inelastic electron tunneling. Importantly, each single electron scattering event must obey fundamental conservation laws. Therefore, the principles outlined in this

Carbon nanotube-cellulose ink for rapid solvent identification

• Tiago Amarante,
• Thiago H. R. Cunha,
• Claudio Laudares,
• Ana P. M. Barboza,
• Ana Carolina dos Santos,
• Cíntia L. Pereira,
• Vinicius Ornelas,
• Bernardo R. A. Neves,
• André S. Ferlauto and
• Rodrigo G. Lacerda

Beilstein J. Nanotechnol. 2023, 14, 535–543, doi:10.3762/bjnano.14.44

• constant of the solvent as shown in Figure 4b. This result suggests that, when the liquid soaks the composite, it swells the material, creating a liquid dielectric barrier between the conductive clusters. Thus, it changes the tunneling process proportionally to the dielectric constant of the liquid. Hence

• pressure of the solvents controls the time the liquid will stay within the sensor before it evaporates. This makes it a key factor regarding the swelling process of the CPC matrix and the electron tunneling process. To investigate this hypothesis, we designed an experiment to mimic the thermal effects

Molecular nanoarchitectonics: unification of nanotechnology and molecular/materials science

• Katsuhiko Ariga

Beilstein J. Nanotechnol. 2023, 14, 434–453, doi:10.3762/bjnano.14.35

• creating a self-assembled monolayer of a diacetylene compound (10,12-nonacosazinoic acid) adsorbed on a graphite surface and biased with a scanning tunneling microscope probe [111]. By positioning the probe at a specific site, the polymerization of the chains was induced within defined small regions, and

• molecules by UV light irradiation. In the process, a cycloaddition reaction occurred between one nearby C60 molecule adsorbed on the surface and the most frontal part of the polydiacetylene molecular skeleton. As a result, nanojunctions were created. Scanning tunneling microscopy proved that the C60

• reversibly terminated by C60 fullerene molecules (Figure 4). First, the Au probe was positioned at the target Br atom site. Then, when the bias voltage was swept, an abrupt change in the tunneling current was detected. As a result, the bromine atoms disappeared from the molecule and the C–Br bonds in the

Cooper pair splitting controlled by a temperature gradient

• Dmitry S. Golubev and
• Andrei D. Zaikin

Beilstein J. Nanotechnol. 2023, 14, 61–67, doi:10.3762/bjnano.14.7

• integrals are taken over the contact areas , and tr(x) denote coordinate- and spin-independent tunneling amplitudes. Let us denote the probability for N1 and N2 electrons to be transferred, respectively, through the junctions 1 and 2 during the observation time t as Pt(N1,N2). Introducing the so-called

• tunneling between the leads, Further analysis of the general expression for the function (Equation 8) is essentially identical to that already carried out in [25]. Therefore, it is not necessary to go into details here. Employing Equation 7 and making use of the results [25], we recover general expressions

• appreciable also at non-zero bias voltages V1,2, in which case it essentially depends on transmission distributions in both junctions. We start from the tunneling limit A1,n, A2,m ≪ 1, where one has Keeping only the terms ∝γ± in the expression (Equation 19), we obtain The first and the second terms on the

From a free electron gas to confined states: A mixed island of PTCDA and copper phthalocyanine on Ag(111)

• Alfred J. Weymouth,
• Emily Roche and
• Franz J. Giessibl

Beilstein J. Nanotechnol. 2022, 13, 1572–1577, doi:10.3762/bjnano.13.131

• of the sample preparation is available in Supporting Information File 1. A qPlus AFM/STM sensor [21] with an etched W-tip was used. Tunneling spectoscopy data (dI/dV data) were acquired with a lock-in amplifier included in the control electronics (Nanonis from SPECS GmbH). The AC signal had a