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

• a long-term Au electrodeposition from acidic electrolyte with pH < 5 leads to the degradation of the AAO template, characterized by a low chemical stability in the as-prepared amorphous state [28][29]. Thus, the proposed design and strategy for the fabrication of the Au NEAs include the formation of

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

• , amorphous substrates. The glasses were cleaned with chloroform before their use in recrystallization studies. Highly oriented pyrolytic graphite (HOPG) was used as non-polar, crystalline substrates (SPI supplies, West Chester, USA). Freshly cleaned HOPG surfaces were prepared by stripping off a layer of

• extended periods of time. Here, wax and pure ß-diketone dissolved in chloroform were recrystallized on non-polar crystalline HOPG and on polar amorphous glass. Recrystallization on the artificial substrates showed an unequal distribution of the deposited wax and of ß-diketone. Therefore, it took several

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

• University of Science and Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw, Poland 10.3762/bjnano.12.60 Abstract Today, silicon solar cells (amorphous films and wafer-based) are a main source of green energy. These cells and their components are produced by employing various technologies. Unfortunately

• prepared by the Fraunhofer Institute (Germany), the solar cells (SCs) market is dominated by silicon [2]. In 2019, monocrystalline, polycrystalline, and amorphous silicon accounted for about 95% of the PV market. The highest (laboratory device) efficiency for monocrystalline and polycrystalline silicon

A review of defect engineering, ion implantation, and nanofabrication using the helium ion microscope

• Frances I. Allen

Beilstein J. Nanotechnol. 2021, 12, 633–664, doi:10.3762/bjnano.12.52

• flake from semiconducting to insulating at a dose of ca. 1 × 1015 ions/cm2 [25]. The dose-versus-resistivity plot from this work is shown in Figure 2a. Upon increasing the dose to ca. 1 × 1017 ions/cm2, the material became amorphous, and the conductivity behavior changed to metallic. This was attributed

• by localized helium ion irradiation. For example, using a helium ion dose of 5 × 1014 ions/cm2, permanent local tuning of the charge density in an amorphous thin film of the semiconductor indium gallium zinc oxide (film thickness 50 nm) has been demonstrated, thereby enabling activation of the

• devices (SQUIDs) was demonstrated, using the helium line irradiation method to direct-write metallic and insulating Josephson junctions into pre-fabricated YBCO circuits [38]. By increasing the helium ion dose further, to the order of 1017 ions/cm2, highly resistive (amorphous) regions can be patterned

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

• significantly enhanced the wettability and photocatalytic performance due to the plasma oxidizing the polymer. In addition, they [83] prepared a crystalline benzo[1,2-b:4,5-b']bis[1]benzothiophene sulfone-containing covalent organic framework (P67) (Figure 8), which exhibited a higher HER than its amorphous or

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

• min. A drop of the resulting suspension was applied to a standard copper mesh with a diameter of 3.05 mm, covered with a 5–6 nm thick layer of amorphous carbon. Next, the sample was dried in air at room temperature for 60 min. The histograms of platinum nanoparticle size distribution in the catalysts

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

• presence of an amorphous film of native oxides gives rise to midgap surface states in GaAs [8] which results in Fermi-level pinning [9]. Due to a high surface-related recombination velocity, a decrease in the photoluminescence (PL) of the semiconductor is also observed [7]. These phenomena have strong and

Structural and optical characteristics determined by the sputtering deposition conditions of oxide thin films

• Petronela Prepelita,
• Florin Garoi and
• Valentin Craciun

Beilstein J. Nanotechnol. 2021, 12, 354–365, doi:10.3762/bjnano.12.29

• was done to determine the type of structure (e.g., polycrystalline or amorphous) and orientation of the thin films. Figure 1 shows typical XRD patterns of ZnO thin films with increasing thickness and prepared via rfMS. Following the effect of the deposition parameters of the oxide films we found that

• thermal treatment, which induces an internal stress in the ZnO thin films. To the same extent, with the depositions made at room temperature on all SiO2 thin films, their structure proved to be essentially amorphous [28][37] with no sharp XRD reflection lines and featuring a matte surface. Based on XPS

• obtained from a source target. In the case of SiO2 thin films, it was confirmed by X-ray diffraction measurements that all structures were amorphous. Following X-ray diffraction analyses, it was proved that ZnO films show an orientation with the c-axis perpendicular to the substrate surface. The results

Scanning transmission helium ion microscopy on carbon nanomembranes

• Daniel Emmrich,
• Annalena Wolff,
• Nikolaus Meyerbröker,
• Jörg K. N. Lindner,
• André Beyer and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2021, 12, 222–231, doi:10.3762/bjnano.12.18

• contribution that is overlaying the STIM signal in later experiments, a CNM with a thickness of about 2 nm was imaged (Figure 2). This amorphous and insulating membrane is placed on a conductive Quantifoil TEM support grid. The sample was first imaged in a configuration that excludes all transmitted ions from

• measurement of this spot is compared to a non-exposed part of the membrane. The non-exposed membrane shows barely visible D and G bands on a strong photoluminescence background as it is reported for amorphous hydrogenated carbon films [32]. After exposure to TEM, the photoluminescence drops and the D and G

• bands become more pronounced, similar to a film of high-temperature annealed nanographite [33]. It was previously demonstrated in TEM that, at an energy of 80 keV, a graphitization of free-standing amorphous carbon can be induced [34]. It is also known that CNMs can turn from the amorphous state into

A review on the green and sustainable synthesis of silver nanoparticles and one-dimensional silver nanostructures

• Sina Kaabipour and
• Shohreh Hemmati

Beilstein J. Nanotechnol. 2021, 12, 102–136, doi:10.3762/bjnano.12.9

• amorphous calcium phosphate particles for enhanced adhesive applications [124]. The spray pyrolysis process requires using an atomizer, a tube furnace, a reaction tube, a collection filter, and a vacuum pump [124]. This method is also often used for production of metal powders and demonstrates less

The role of gold atom concentration in the formation of Cu–Au nanoparticles from the gas phase

• Yuri Ya. Gafner,
• Svetlana L. Gafner,
• Darya A. Ryzkova and
• Andrey V. Nomoev

Beilstein J. Nanotechnol. 2021, 12, 72–81, doi:10.3762/bjnano.12.6

• amorphous carbon or magnesium oxide substrates by the laser evaporation of a bulk alloy with various stoichiometric compositions (Cu–Au, Cu3Au, and Au3Cu). An analysis of individual clusters carried out by using electron diffraction and high-resolution transmission electron microscopy (HRTEM) showed that Cu

• –Au clusters are formed with chemical compositions corresponding to the composition of the evaporated material [14]. In the case of cluster deposition onto amorphous carbon, various cluster morphologies were observed, such as cuboctahedral and decahedral. For clusters supported on a MgO substrate

• copper (aCu = 3.610 Å) is an evidence that the nanoparticles deposited onto the amorphous carbon substrate were a Cu–Au nanoalloy [3]. Next, we analyzed the structure of the Cu3Au nanoparticles [3] in order to determine the possible temperature of the nanoparticles at the moment of their collision with

Effect of different silica coatings on the toxicity of upconversion nanoparticles on RAW 264.7 macrophage cells

• Cynthia Kembuan,
• Helena Oliveira and
• Christina Graf

Beilstein J. Nanotechnol. 2021, 12, 35–48, doi:10.3762/bjnano.12.3

• protect UCNPs surfaces from dissolution. In contrast to a more complex polymeric coating, silica surfaces can be easily functionalized with a wide range of coupling agents and biomolecules, and the interior of the silica shell can be modified by integrating dye molecules, for example. However, amorphous

• that even a thin silica coating shell of <2 nm or of 5 nm can already reduce the luminescence quenching of UCNPs in an aqueous dispersion [19]. Besides, several studies revealed that silica-coated UCNPs have a low toxicity in vitro and in vivo compared with other nanoparticles [7][11][39]. Amorphous

• lanthanide core. It has to be considered that amorphous silica obtained from a Stöber-like growth process is an inherently porous material with a pore size of 1–4 nm [35][36]. Thus, it contains pores that are larger than water molecules, as well as lanthanide and other ions (e.g., Na+ and F−) that are

Atomic layer deposited films of Al₂O₃ on fluorine-doped tin oxide electrodes: stability and barrier properties

• Hana Krýsová,
• Michael Neumann-Spallart,
• Hana Tarábková,
• Pavel Janda,
• Ladislav Kavan and
• Josef Krýsa

Beilstein J. Nanotechnol. 2021, 12, 24–34, doi:10.3762/bjnano.12.2

• -deposited ALD Al2O3 films are typically amorphous with a poor resistance to chemical attack [11][12][13]. These films do not withstand, for example, exposition to environmental media, such as 5% NaCl and sea water, to diluted HCl and H2SO4 (pH 4) [11], to acidic (1 M H2SO4) or alkaline (1 M NaOH) solutions

• amorphous to polycrystalline γ-Al2O3 [12] or to oriented θ-Al2O3 [13]. However, on thermodynamic grounds, alumina is soluble in both acidic and alkaline media [8]. Besides protection, Al2O3 ALD layers have also been used for passivating surface states on water-oxidizing hematite photoanodes [14][15]. Very

Bio-imaging with the helium-ion microscope: A review

• Matthias Schmidt,
• James M. Byrne and
• Ilari J. Maasilta

Beilstein J. Nanotechnol. 2021, 12, 1–23, doi:10.3762/bjnano.12.1

Scanning transmission imaging in the helium ion microscope using a microchannel plate with a delay line detector

• Eduardo Serralta,
• Nico Klingner,
• Olivier De Castro,
• Michael Mousley,
• Santhana Eswara,
• Serge Duarte Pinto,
• Tom Wirtz and
• Gregor Hlawacek

Beilstein J. Nanotechnol. 2020, 11, 1854–1864, doi:10.3762/bjnano.11.167

• high-angle scattering events, or moving it down to increase the angular resolution and distance for time-of-flight measurements. With this new system, we show composition-dependent contrast for amorphous materials and the contrast difference between small-angle and high-angle scattering signals. We

• using the beam deflected in a polar and azimuthal angular sector. For amorphous materials under perpendicular incidence, the transmitted beam is expected to be scattered symmetrically around the axis of incidence. The average polar angle of scattering depends on both the material and the thickness of

• transmission imaging mode and further tuning of acceptance angles can be done in post-processing. Additionally, ToF-resolved recording of the transmission events can be integrated into this system. Here, we use this system to study the mass-thickness-dependent contrast in amorphous materials and demonstrate

Unravelling the interfacial interaction in mesoporous SiO₂@nickel phyllosilicate/TiO₂ core–shell nanostructures for photocatalytic activity

• Bridget K. Mutuma,
• Xiluva Mathebula,
• Isaac Nongwe,
• Bonakele P. Mtolo,
• Boitumelo J. Matsoso,
• Rudolph Erasmus,
• Zikhona Tetana and
• Neil J. Coville

Beilstein J. Nanotechnol. 2020, 11, 1834–1846, doi:10.3762/bjnano.11.165

• to the presence of amorphous silica. In the mSiO2@NiPS sample, this peak could be correlated to an overlap of silica with the (002) plane of nickel phyllosilicate [35]. Additional peaks at 2θ = 34°, 36°, and 60° in the mSiO2@NiPS sample were assigned to (200), (202), and (060) diffractions of the 1:1

Nanocasting synthesis of BiFeO₃ nanoparticles with enhanced visible-light photocatalytic activity

• Thomas Cadenbach,
• Maria J. Benitez,
• A. Lucia Morales,
• Cesar Costa Vera,
• Luis Lascano,
• Francisco Quiroz,
• Alexis Debut and
• Karla Vizuete

Beilstein J. Nanotechnol. 2020, 11, 1822–1833, doi:10.3762/bjnano.11.164

• diameter corresponding to the pore size of the porous matrix and, consequently, by a high specific surface area. Silica matrices, such as Santa Barbara Amorphous silica (SBA-15) or Korean Advanced Institute of Science and Technology silica (KIT-6), have been used successfully as hard templates to

• acid (TA) as complexing reagents and HNO3-acidified water as solvent, we found only amorphous products, as observed in the X-ray diffractograms in Figure 1. This result can be attributed to the incorporation of Lewis-acidic metals, such as bismuth, into the amorphous silica framework during the

• reaction, which leads to overall amorphous products [44][45][46][47]. The impact on the phase formation of BiFeO3 of using different alcohols, that is, 2-methoxyethanol and ethanol as solvents and tartaric acid as a complexing reagent in the synthesis is shown in Figure 2. Ethanol is commonly used in

Molecular dynamics modeling of the influence forming process parameters on the structure and morphology of a superconducting spin valve

• Alexander Vakhrushev,
• Aleksey Fedotov,
• Vladimir Boian,
• Roman Morari and
• Anatolie Sidorenko

Beilstein J. Nanotechnol. 2020, 11, 1776–1788, doi:10.3762/bjnano.11.160

• reach 12, which corresponds to the ideal crystalline state of a hexagonal close-packed lattice, indicating an amorphous-like structure of cobalt nanofilms. Variations in the coordination number within the intermediate niobium layer are more significant. When approaching the contact regions with cobalt

• the coordination number distribution in the material showed that the layers have a different structure when multilayer nanofilms are formed under normal conditions. The niobium substrate structure is close to crystalline; cobalt nanofilms are characterized by an amorphous-like structure. In the

Absorption and photoconductivity spectra of amorphous multilayer structures

• Oxana Iaseniuc and
• Mihail Iovu

Beilstein J. Nanotechnol. 2020, 11, 1757–1763, doi:10.3762/bjnano.11.158

• Oxana Iaseniuc Mihail Iovu Institute of Applied Physics, No. 5 Academiei Str., Chisinau, MD-2028, R. Moldova 10.3762/bjnano.11.158 Abstract The experimental results regarding optical absorption and steady-state photoconductivity of amorphous single-layer structures (Al–As0.40S0.30Se0.30–Al, Al

• –Ge0.09As0.09Se0.82–Al, and Al–Ge0.30As0.04S0.66–Al) and of an amorphous heterostructure (Al–As0.40S0.30Se0.30/Ge0.09As0.09Se0.82/Ge0.30As0.04S0.66–Al) at different values of the voltage, with positive or negative polarity, applied to the illuminated top Al electrode are presented and discussed. The complex structure

• of the photocurrent spectra is attributed to the different values of the optical bandgap of the involved amorphous layers (Eg ≈ 2.0 eV for As0.40S0.30Se0.30 and Ge0.09As0.09Se0.82 and Eg ≈ 3.0 eV for Ge0.30As0.04S0.66). The obtained experimental results are discussed taking into account the light

Amorphized length and variability in phase-change memory line cells

• Nafisa Noor,
• Sadid Muneer,
• Raihan Sayeed Khan,
• Anna Gorbenko and
• Helena Silva

Beilstein J. Nanotechnol. 2020, 11, 1644–1654, doi:10.3762/bjnano.11.147

• by direct imaging. In this work, the length of amorphized regions in multiple identical Ge2Sb2Te5 (GST) line cells was extracted from electrical measurements. After each cell was programmed to an amorphous state, a sequence of increasing-amplitude post-reset voltage pulses separated by low-amplitude

• , significant variability arises from the intrinsically unique crystallization and amorphization processes in these devices. For example, cells programmed to an amorphous resistance of approx. 50 MΩ show threshold voltage values of 5.5–7.5 V, corresponding to amorphized length values of 290–395 nm. This

• unpredictable programming feature in phase-change memory devices can be utilized in hardware security applications. Keywords: amorphous materials; drift; electrical breakdown; electrical resistivity; phase-change memory; pulse measurement; stochastic processes; threshold switching; Introduction Phase-change

Optically and electrically driven nanoantennas

• Monika Fleischer,
• Dai Zhang and
• Alfred J. Meixner

Beilstein J. Nanotechnol. 2020, 11, 1542–1545, doi:10.3762/bjnano.11.136

• revealing local structural properties is illustrated in [49], where crystalline and amorphous regions within core–shell silicon nanowires are discerned with an optical resolution of a few nanometers. This study further demonstrates that it is possible to combine polarization angle-resolved experiments with

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

• amorphous layer (Ar/H2 ≈59, Figure 4d, right panel). Raman spectroscopy was performed to determine the quality (defect density, defect type, and hybridization) of the deposited Pt/CNW layers. All samples produced at sufficiently high pressures and low carrier gas flow rates exhibit the typical spectrum

An atomic force microscope integrated with a helium ion microscope for correlative nanoscale characterization

• Santiago H. Andany,
• Gregor Hlawacek,
• Stefan Hummel,
• Charlène Brillard,
• Mustafa Kangül and
• Georg E. Fantner

Beilstein J. Nanotechnol. 2020, 11, 1272–1279, doi:10.3762/bjnano.11.111

• amorphous silicon bubbles at the surface [34]. Furthermore, focused helium ion beam exposure inside a HIM can be used as a way of locally replicating the harsh radiation conditions found in nuclear fission and fusion reactors, to study the response of structural materials used in the reactors [35]. We

• characterized the defects caused by He ion exposure in a correlative AFM–HIM experiment. Amorphous silicon bubbles are created on a crystalline silicon substrate through point exposition with the HIM at 25 kV and 14 pA using doses between 4.2 × 108 and 4.2 × 109 He ions (Figure 3). He ions penetrate deep into

Proximity effect in [Nb(1.5 nm)/Fe(x)]₁₀/Nb(50 nm) superconductor/ferromagnet heterostructures

• Yury Khaydukov,
• Sabine Pütter,
• Laura Guasco,
• Roman Morari,
• Gideok Kim,
• Thomas Keller,
• Anatolie Sidorenko and
• Bernhard Keimer

Beilstein J. Nanotechnol. 2020, 11, 1254–1263, doi:10.3762/bjnano.11.109

• are visible in the RHEED pattern of the Nb layer, which indicate island growth and polycrystallinity (Figure 2d). Subsequently, the Fe/Nb multilayers were grown on the 800 °C Nb buffer. The corresponding RHEED patterns exhibit amorphous growth, i.e., blurred screens (not shown). Increasing the Fe film

• thickness from 2 to 4 nm improves the film quality. The Fe layer becomes polycrystalline while the Nb layer remains amorphous. In contrast, for sample s6, which was grown on the 30 °C Nb buffer, both layers reveal polycrystallinity with a certain texture (Figure 2e,f). Finally, the Pt cap is always

• not observe any antiferromagnetic coupling, neither at room temperature nor in low-temperature measurements. The reason of this disagreement may originate from the amorphous Nb spacers. The proximity of this depth-modulated and weakly magnetic layer to a thick superconductor causes the appearance of

Gas sorption porosimetry for the evaluation of hard carbons as anodes for Li- and Na-ion batteries

• Yuko Matsukawa,
• Fabian Linsenmann,
• Maximilian A. Plass,
• George Hasegawa,
• Katsuro Hayashi and
• Tim-Patrick Fellinger

Beilstein J. Nanotechnol. 2020, 11, 1217–1229, doi:10.3762/bjnano.11.106

• area (SSA) of the anode materials as well as the deposition of amorphous carbon films were shown to reduce irreversible capacity losses [22][23]. Ji et al. found that lower total pore volumes (determined by N2 sorption) gave rise to increased reversible sodium storage capacities for sucrose-derived HCs

• to disordered, amorphous HCs with missing sharp (002) and (101) reflections (Supporting Information File 1, Figure S2). The described features were also found for the RF samples as reported earlier by Hasegawa and co-workers (Supporting Information File 1, Figure S3) [28][29]. The position of the

• only related to the measurable surface area for amorphous electrode materials. One may consider different deposition mechanisms (e.g., van der Merwe layer-by-layer or Volmer–Weber island growth) to explain this. However, it is more likely related to different contributions of porosity that is even