Open-loop amplitude-modulation Kelvin probe force microscopy operated in single-pass PeakForce tapping mode

• Gheorghe Stan and
• Pradeep Namboodiri

Beilstein J. Nanotechnol. 2021, 12, 1115–1126, doi:10.3762/bjnano.12.83

• various contributions from the probe geometry and imaged features of the sample. In contrast to this, the currently implemented closed-loop (CL) variants of KPFM, either amplitude-modulation (AM) or frequency-modulation (FM), solely report on their final product in terms of the tip–sample contact

• potential difference. In ambient atmosphere, both CL AM-KPFM and CL FM-KPFM work at their best during the lift part of a two-pass scanning mode to avoid the direct contact with the surface of the sample. In this work, a new OL AM-KPFM mode was implemented in the single-pass scan of the PeakForce Tapping

• (PFT) mode. The topographical and electrical components were combined in a single pass by applying the electrical modulation only in between the PFT tip–sample contacts, when the AFM probe separates from the sample. In this way, any contact and tunneling discharges are avoided and, yet, the location of

Criteria ruling particle agglomeration

• Dieter Vollath

Beilstein J. Nanotechnol. 2021, 12, 1093–1100, doi:10.3762/bjnano.12.81

• known, as a first approximation, the energy of interaction was assumed to be proportional to the number of contact points. As smallest number, for each particle one contact point was assumed. Luo et al. [12] estimate the energy of interaction in the range of approximately h0 = 10 eV (1.6 × 10−18 J

Assessment of the optical and electrical properties of light-emitting diodes containing carbon-based nanostructures and plasmonic nanoparticles: a review

• Keshav Nagpal,
• Erwan Rauwel,
• Frédérique Ducroquet and
• Protima Rauwel

Beilstein J. Nanotechnol. 2021, 12, 1078–1092, doi:10.3762/bjnano.12.80

• : electron transport and injection layers Similar to HTL and HIL, ETL and EIL play very crucial roles in optimizing charge carrier injection in OLED and HyLED. The latter follows an inverted OLED architecture (i.e., the EIL is in contact with the cathode followed by ETL). In order to enhance the OLED

A new method for obtaining model-free viscoelastic material properties from atomic force microscopy experiments using discrete integral transform techniques

• Berkin Uluutku,
• Enrique A. López-Guerra and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2021, 12, 1063–1077, doi:10.3762/bjnano.12.79

• force–distance curve, where the cantilever position above the sample follows a ramp function. In the case of intermittent-contact methods (e.g., tapping-mode AFM), the cantilever tip oscillates nearly sinusoidally, but since tip–sample contact is intermittent, the sample does not experience purely

• geometry correction factor discussed above, . For this calculation Δt is a known experimental parameter, and r is chosen by the researcher. Demonstration with AFM contact mechanics So far, we have demonstrated our method for stress–strain inputs using the generalized Voigt model. However, in AFM

• z-domain. The theoretical retardance is evaluated using Equation 29 (see Supporting Information File 1 for its derivation): A spherical contact, appropriate for an AFM experiment, was simulated using the same material parameters, with a tip radius of 10 nm, which is common in AFM (See also Figure 2

Use of nanosystems to improve the anticancer effects of curcumin

• Andrea M. Araya-Sibaja,
• Norma J. Salazar-López,
• Krissia Wilhelm Romero,
• José R. Vega-Baudrit,
• J. Abraham Domínguez-Avila,
• Carlos A. Velázquez Contreras,
• Ramón E. Robles-Zepeda,
• Mirtha Navarro-Hoyos and
• Gustavo A. González-Aguilar

Beilstein J. Nanotechnol. 2021, 12, 1047–1062, doi:10.3762/bjnano.12.78

• ]. However, both authors only carried out release studies at pH 7.4, so the question of the behavior of LPN at an acid pH remains. Nanoemulsions. Nanoemulsions are composed of an oil phase in a continuous aqueous phase, with average diameters <200 nm [88][89]. The oil and aqueous phases contact each other

An overview of microneedle applications, materials, and fabrication methods

• Zahra Faraji Rad,
• Philip D. Prewett and
• Graham J. Davies

Beilstein J. Nanotechnol. 2021, 12, 1034–1046, doi:10.3762/bjnano.12.77

• parameters determining flow in a microchannel include blood viscosity, contact angle, hydrodynamic diameter, and driving forces such as surface tension. In addition, due to the elastic nature of the skin and its irregular surface, varying from person to person, and with age and position on the body, the

• light. The resist is sprayed or spin coated onto a substrate surface for patterning and is exposed to light (usually ultraviolet) either through a contact mask or using a projection stepper, followed by wet development to form a resist pattern. This technique requires well-established photosensitive

A Au/CuNiCoS₄/p-Si photodiode: electrical and morphological characterization

• Adem Koçyiğit,
• Adem Sarılmaz,
• Teoman Öztürk,
• Faruk Ozel and
• Murat Yıldırım

Beilstein J. Nanotechnol. 2021, 12, 984–994, doi:10.3762/bjnano.12.74

• /H2O (1:10) solution for eliminating the oxide layer and impurities from the surfaces. An ohmic contact with low resistance was made by evaporation of aluminium (Al, 99.999% from Kurt J. Lesker) with a thickness of 150 nm at 5 × 10−6 Torr on the back side of the p-type Si substrate and subsequent

• /CuNiCoS4/p-Si photodiode, and it can be determined from I–V characteristics [28]. Rj contains two components: shunt resistance (Rsh) due to contact of the metal–semiconductor interface and series resistance (Rs) owing to interfacial layers [29]. Rj can be calculated as follows: The Rj–V plots of the Au

Uniform arrays of gold nanoelectrodes with tuneable recess depth

• Elena O. Gordeeva,
• Ilya V. Roslyakov,
• Alexey P. Leontiev,
• Alexey A. Klimenko and
• Kirill S. Napolskii

Beilstein J. Nanotechnol. 2021, 12, 957–964, doi:10.3762/bjnano.12.72

• array and the ability to control the recess depth, and (4) a predictable number of nanoelectrodes in electrical contact with the current collector. In the present study, the first two points are fulfilled by using AAO as a template and Au as the material of the working part of the nanoelectrodes. To

• with electrical contact, Cu was re-deposited on the surface of the Au segments (Figure 3a). The experiment was carried out at Ed = −0.1 V and limited by the electrical charge density, which is equal to the corresponding value in the case of electrodeposition of the first Cu segment. SEM images of the

• AAO surface after Cu re-deposition are shown in Figure 3b,c. The Au nanoelectrodes having electrical contact with the current collector manifest themselves as white dots, indicating that Cu reaches the template surface. Contrary, the black dots correspond to the pores containing recessed Au electrodes

Molecular assemblies on surfaces: towards physical and electronic decoupling of organic molecules

• Sabine Maier and
• Meike Stöhr

Beilstein J. Nanotechnol. 2021, 12, 950–956, doi:10.3762/bjnano.12.71

• . To a lesser extent, metal oxides have also been used, for which defects and charging often pose additional challenges [44][45][46]. On electronically insulating surfaces, non-contact atomic force microscopy (AFM) is the method of choice to study molecular assemblies and individual molecules in real

Self-assembly of Eucalyptus gunnii wax tubules and pure ß-diketone on HOPG and glass

• Miriam Anna Huth,
• Axel Huth and
• Kerstin Koch

Beilstein J. Nanotechnol. 2021, 12, 939–949, doi:10.3762/bjnano.12.70

• amounts of deposited mass. This phenomenon known as “coffee ring effect” is caused by capillary flow of the solvent from the middle of the droplet towards its three-phase (solid–liquid–air) contact line. During evaporation, the molecules are aggregated on the outer edge of the droplet where evaporation is

In situ transport characterization of magnetic states in Nb/Co superconductor/ferromagnet heterostructures

• Olena M. Kapran,
• Roman Morari,
• Taras Golod,
• Evgenii A. Borodianskyi,
• Vladimir Boian,
• Andrei Prepelita,
• Nikolay Klenov,
• Anatoli S. Sidorenko and
• Vladimir M. Krasnov

Beilstein J. Nanotechnol. 2021, 12, 913–923, doi:10.3762/bjnano.12.68

• the whole electrode is measured in a four-probe manner using two separate wires bonded to each contact pad. Results Figure 1d shows Rxx(T) dependencies, normalized by the normal state resistance Rn (T ≥ Tc), for microbridges at S1 (blue) and S2 (red) MLs at H = 0. Resistances are measured with Iac

• landscape for vortices: vortices are pinned to domains and cannot move across them, but can freely move along domain walls [55]. Therefore, we expect that the magnetic state of a ML may influence the FF resistance. Figure 1h shows Rxx(T) for a vertical bridge at the S1 sample measured with the contact

• bridge with widths of a few micrometers. The inset shows the contact configuration for simultaneous measurements of longitudinal and Hall resistances in panels (h) and (i). The orange arrow indicates the orientation of the magnetic field in all experiments. (b) Magnetization curve of an unpatterned Nb(25

Modification of a SERS-active Ag surface to promote adsorption of charged analytes: effect of Cu²⁺ ions

• Bahdan V. Ranishenka,
• Andrei Yu. Panarin,
• Irina A. Chelnokova,
• Sergei N. Terekhov,
• Peter Mojzes and
• Vadim V. Shmanai

Beilstein J. Nanotechnol. 2021, 12, 902–912, doi:10.3762/bjnano.12.67

• support (slide) depending on the time of contact with Ag NPs. The maximum absorption value stabilizes after approximately 12 h with a shift from 412 to 427 nm. We suppose that the redshift of the absorption maximum is due to the plasmon interactions of the closely packed NPs. In order to investigate the

The role of convolutional neural networks in scanning probe microscopy: a review

• Ido Azuri,
• Irit Rosenhek-Goldian,
• Neta Regev-Rudzki,
• Georg Fantner and
• Sidney R. Cohen

Beilstein J. Nanotechnol. 2021, 12, 878–901, doi:10.3762/bjnano.12.66

• conditions for band-excitation piezoresponse force microscopy (PFM) [134]. Band excitation collects a band of frequencies around the contact resonance frequency of the tip–sample system, which is modeled by a simple harmonic oscillator equation. This allows for the determination of several physical

• -topographical SPM technique is the study of ferroelectric switching [135]. This switching is a function of both reading and writing voltages, and can vary with experimental conditions such as time and temperature, and is further complicated by competing processes. The measurement technique was contact KPFM

• , which has an inherently low signal due to damped response of the tip in contact with surface. In this case, the data is not surface mappings, but rather hysteresis loops in graphical format, which were “unfolded” by plotting the voltage response as function of the read voltage and writing voltage step

9.1% efficient zinc oxide/silicon solar cells on a 50 μm thick Si absorber

• Rafal Pietruszka,
• Bartlomiej S. Witkowski,
• Monika Ozga,
• Katarzyna Gwozdz,
• Ewa Placzek-Popko and
• Marek Godlewski

Beilstein J. Nanotechnol. 2021, 12, 766–774, doi:10.3762/bjnano.12.60

• deposited as a low-resistivity ohmic contact via sputtering. To improve the contact parameters, the samples were annealed at 500 °C for 5 min in argon atmosphere via rapid thermal processing. Si/Al substrates were prepared in two different ways, A and B. On the surface of sample A, zinc oxide nanorods

• improved electron collection by band offset engineering. On top of the solar structure, AZO was deposited as a transparent contact [17][18]. Trimethylaluminium (TMA, CAS Number 75-24-1) was used as the Al precursor. In the ALD processes, high-purity nitrogen (purity 99.999%) was used as the carrier gas

• hole of 0.1 cm in diameter was placed on the samples. Then, Al was deposited on top via sputtering. The simple point contact was used on top of the structure. To improve the light collection from full-size ZnO/Si SCs, grid-like contacts should be used. The resulting solar cell structures are shown in

Physical constraints lead to parallel evolution of micro- and nanostructures of animal adhesive pads: a review

• Thies H. Büscher and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2021, 12, 725–743, doi:10.3762/bjnano.12.57

• morphology of attachment devices is affected by physical constraints. This resulted in two main types of attachment devices in animals: hairy and smooth. They differ in morphology and ultrastructure but achieve mechanical adaptation to substrates with different roughness and maximise the actual contact area

• influence of different factors, such as substrate roughness and pad stiffness, on contact forces, and review the chemical composition of pad fluids, which is an important component of an adhesive function. Attachment systems are omnipresent in animals. We show parallel evolution of attachment structures on

• contact with a wide range of microscopically rough substrate profiles (Figure 2). Also, due to the low bending stiffness of their terminal plates, can even adapt to substrates with roughness on a sub-nanometre scale [1][3][4][34]. Smooth pads can also maximise their contact areas with a variety of

Electromigration-induced formation of percolating adsorbate islands during condensation from the gaseous phase: a computational study

• Alina V. Dvornichenko,
• Vasyl O. Kharchenko and
• Dmitrii O. Kharchenko

Beilstein J. Nanotechnol. 2021, 12, 694–703, doi:10.3762/bjnano.12.55

• growth of intermetallic compounds between the solder and the metal contact of the integrated circuit (flip-chip technology) [3][4][5][6][7]. The vast majority of research on EM began in the 1970s. Such studies were mostly conducted experimentally. It was shown that the influence of the electric current

• include the formation of surface steps [28][29][30][31], faceting of the surface [32][33][34][35][36][37], elimination of instability of surface morphology caused by stress and wetting of the substrate [38][39][40][41], the evolution of contact irregularities in switches of microelectromechanical systems

Nanogenerator-based self-powered sensors for data collection

• Yicheng Shao,
• Maoliang Shen,
• Yuankai Zhou,
• Xin Cui,
• Lijie Li and
• Yan Zhang

Beilstein J. Nanotechnol. 2021, 12, 680–693, doi:10.3762/bjnano.12.54

• to the safety of vehicle driving and the experience of the driver [5][6][7][8][9][10][11]. The principle of operation of TENGs is the triboelectrification/contact electrification (CE) process [62][63][64]. TENGs have four working modes: the common vertical contact-separation mode, the single

• -electrode mode, the contact-sliding mode, and the freestanding-triboelectric-layer mode [2][65]. TENGs can be made of many different materials with low manufacturing cost, environmental friendliness, and low maintenance cost. TENG-based sensors can collect multidimensional and large-scale data, which are a

• . When the arm is bent, the muscles stretch the sensor to a larger contact area, and a voltage variation is generated by the sensor. An output voltage of about 23 V is generated. When the arm is released, the voltage returns to zero. The peak voltage varies with the bending angle of the elbow, as shown

Nanoporous and nonporous conjugated donor–acceptor polymer semiconductors for photocatalytic hydrogen production

• Zhao-Qi Sheng,
• Yu-Qin Xing,
• Yan Chen,
• Guang Zhang,
• Shi-Yong Liu and
• Long Chen

Beilstein J. Nanotechnol. 2021, 12, 607–623, doi:10.3762/bjnano.12.50

• well as output electrons and build excellent electron-output “tentacles” and therefore increase the HER. Chen et al. [81] reported an ethynyl-bridged FSO–pyrene-based polymer (P66) (Figure 8) to further extend the conjugation. The water contact angle measurements showed that the wettability was

Stability and activity of platinum nanoparticles in the oxygen electroreduction reaction: is size or uniformity of primary importance?

• Kirill O. Paperzh,
• Anastasia A. Alekseenko,
• Vadim A. Volochaev,
• Ilya V. Pankov,
• Olga A. Safronenko and
• Vladimir E. Guterman

Beilstein J. Nanotechnol. 2021, 12, 593–606, doi:10.3762/bjnano.12.49

• platinum NPs and loss of contact with the support [24][25][26], as well as the isolation of particles by adsorbed carbon monoxide released due to carbon oxidation [27][28][29][30]. Each of the mechanisms previously described can play a greater or smaller role, depending on the conditions of the catalysts

• ). A similar difference is observed when we compared G40 and the JM40 analog (Figure 2). We estimated the uniformity of the spatial NP distribution over the support surface. To this end, for each Pt/M material in the TEM micrographs, we calculated the fraction of NPs that were not in contact (non

• -overlapping) with other NPs or in contact with one, two, or three other NPs. In this case, with the assumption that the smaller the number of intersections of NP images in the micrographs, the more uniformly distributed over the carrier surface the NPs. The disadvantages of such a simplified system used for

Impact of GaAs(100) surface preparation on EQE of AZO/Al₂O₃/p-GaAs photovoltaic structures

• Piotr Caban,
• Rafał Pietruszka,
• Jarosław Kaszewski,
• Monika Ożga,
• Bartłomiej S. Witkowski,
• Krzysztof Kopalko,
• Piotr Kuźmiuk,
• Katarzyna Gwóźdź,
• Ewa Płaczek-Popko,
• Krystyna Lawniczak-Jablonska and
• Marek Godlewski

Beilstein J. Nanotechnol. 2021, 12, 578–592, doi:10.3762/bjnano.12.48

• ) [23][24][25]. Therefore, one should limit the contact time of the GaAs substrate with air/water to an absolute minimum. The attempts that were made to either stop or at least reduce this phenomenon led to the use of surface passivation techniques. One of the well-known and effective methods to protect

• the experiment, the substrate was equipped with an e-beam evaporated (Kurt J. Lesker PVD75) and annealed Au/Zn/Au bottom ohmic contact, which was protected with Kapton tape before further processing steps. In total, eight GaAs samples, denoted as A1–A4 and B1–B4, were fabricated and they differed in

• the same or similar etching rates). After etching in a mixture of CA + H2O2 + H2O, the samples were washed in DIW for 1 min in a USC. Prior contact with an oxidizer as well as the subsequent water bath also resulted in an infinitesimal oxide layer reformation on the surface. This oxide layer was, then

Properties of graphene deposited on GaN nanowires: influence of nanowire roughness, self-induced nanogating and defects

• Jakub Kierdaszuk,
• Piotr Kaźmierczak,
• Justyna Grzonka,
• Aleksandra Krajewska,
• Aleksandra Przewłoka,
• Wawrzyniec Kaszub,
• Zbigniew R. Zytkiewicz,
• Marta Sobanska,
• Maria Kamińska,
• Andrzej Wysmołek and
• Aneta Drabińska

Beilstein J. Nanotechnol. 2021, 12, 566–577, doi:10.3762/bjnano.12.47

• different nanowire substrates shows that bigger differences in nanowires height increase graphene strain, while a higher number of nanowires in contact with graphene locally reduces the strain. Moreover, the value of graphene carrier concentration is found to be correlated with the density of nanowires in

• contact with graphene. The lowest concentration of defects is observed for graphene deposited on nanowires with the lowest density. The contact between graphene and densely arranged nanowires leads to a large density of vacancies. On the other hand, grain boundaries are the main type of defects in

• , such as strain induced by mechanical contact between materials or gating of graphene by neighbouring layers, are important for further applications. Furthermore, electron scattering on defects modifies graphene properties in several ways, for example, additional scattering centres reduce carrier

Local stiffness and work function variations of hexagonal boron nitride on Cu(111)

• Abhishek Grewal,
• Yuqi Wang,
• Matthias Münks,
• Klaus Kern and
• Markus Ternes

Beilstein J. Nanotechnol. 2021, 12, 559–565, doi:10.3762/bjnano.12.46

• the contact potential difference measured by Kelvin probe force microscopy. Using 3D force profiles of the same area we determine the relative stiffness of the Moiré region allowing us to analyse both electronic and mechanical properties of the 2D layer simultaneously. We obtain a sheet stiffness of

• non-contact atomic force microscopy (nc-AFM) to study h-BN on Cu(111). This template has interesting properties because the dielectric layer is only very weakly bound to the metal and shows an electronically induced Moiré superstructure [25][26]. First STM studies on this system pointed to only a

• by the applied voltage, which compensates the contact potential difference between Φ of the tip and Φ of the sample [44]. Using the shift of the FER we find an average variation between valley and rim regions of ΔΦ = 148 ± 17 meV, which agrees well with previous observations [27][45]. Interestingly

Influence of electrospray deposition on C₆₀ molecular assemblies

• Antoine Hinaut,
• Sebastian Scherb,
• Sara Freund,
• Zhao Liu,
• Thilo Glatzel and
• Ernst Meyer

Beilstein J. Nanotechnol. 2021, 12, 552–558, doi:10.3762/bjnano.12.45

• the first molecules studied in HV-ESD experiments [5][30]. Here, we present a comparison between TE and HV-ESD regarding the adsorption and structure formation of C60 molecules on surfaces at low coverages, that is, below one monolayer down to single molecules. We used a non-contact atomic force

• in Figure 3c. The islands are clearly different to what is obtained after TE of C60, also shown by the zoom on such an island in Figure 3e. Their average contact area, that is, the surface occupied by the first layer on the KBr surface, is about 1100 nm2, less than a tenth of what is obtained after

• were obtained. Room-temperature AFM Room-temperature nc-AFM measurements were performed with a custom-built non-contact atomic force microscope with Nanonis electronics RC5. PPP-NCL cantilevers (Nanosensor) were used as sensor (typical resonance frequency of f1 = 170 kHz, oscillation amplitude A1 = 2–5

The preparation temperature influences the physicochemical nature and activity of nanoceria

• Robert A. Yokel,
• Wendel Wohlleben,
• Johannes Georg Keller,
• Matthew L. Hancock,
• Jason M. Unrine,
• D. Allan Butterfield and
• Eric A. Grulke

Beilstein J. Nanotechnol. 2021, 12, 525–540, doi:10.3762/bjnano.12.43

• stable complexes with phosphate but phosphate inhibits nanoceria dissolution, it was hypothesized that phosphates not in direct contact with nanoceria would create a sink for released cerium ions and increase the nanoceria dissolution rate. Assuming that NM-212 was calcined to a crystalline form with

• pH 4.5. This experiment was repeated with 40 or 75 mg LN resin and sampling up to 3360 h. This experiment was similarly conducted with 75 mg HTP at pH 4.5 and pH 7 with samples collected up to 2016 h. To test the hypothesis that phosphates not in direct contact with nanoceria increase the nanoceria

• (log Ksp = 10−26 to 10−23 for Ce(III) phosphate in 0.01 to 12 M H3PO4, 0.1 M NaH2PO4, or 0.1 M HCl [66][67][68]; log Ksp = 10−115 for Ce(IV) phosphate in 0.01 to 12 M H3PO4 and 10−34 at pH 0.4 [66][69]). The present study assessed the hypothesis that phosphate groups not in direct contact with

Determining amplitude and tilt of a lateral force microscopy sensor

• Oliver Gretz,
• Alfred J. Weymouth,
• Thomas Holzmann,
• Korbinian Pürckhauer and
• Franz J. Giessibl

Beilstein J. Nanotechnol. 2021, 12, 517–524, doi:10.3762/bjnano.12.42

• atomic force microscopy (AFM) is a non-contact atomic force microscopy technique where the frequency shift (Δf) of an oscillating tip is detected [1]. The frequency shift is a measure of the total force gradient acting on the tip, which includes both long-range and short-range contributions. A typical