Morphology-driven gas sensing by fabricated fractals: A review

• Vishal Kamathe and
• Rupali Nagar

Beilstein J. Nanotechnol. 2021, 12, 1187–1208, doi:10.3762/bjnano.12.88

• study, Kante et al. prepared SnO2 films with fractal morphology by an electrochemical method with a subsequent oxidation process [68]. Both groups tested the films for CO gas sensing at different temperatures. Figure 8a–d shows the SEM images of SnO2 thin films on a Si(100) substrate obtained by Chen

• the sensor, while Figure 12d shows individual EDS maps of Si, Pt, O, and Ti. The fabricated sensor displayed good sensitivity towards acetone under exposure to UV light with a detection limit greater than 97% at 10 ppb. The exceptional sensitivity achieved was attributed to high porosity, network

• -assisted chemical etching was used by Qin et al. [79] to prepare a dendritic array of Si/WO3 NW composites, which was tested for the detection of NO2 gas at room temperature. Figure 17a–e SEM and high-resolution transmission electron microscopy (HR-TEM) images of Si/WO3 NWs. Figure 17f shows the XRD

Irradiation-driven molecular dynamics simulation of the FEBID process for Pt(PF₃)₄

• Alexey Prosvetov,
• Alexey V. Verkhovtsev,
• Gennady Sushko and
• Andrey V. Solov’yov

Beilstein J. Nanotechnol. 2021, 12, 1151–1172, doi:10.3762/bjnano.12.86

• substrate The first step of the FEBID simulation procedure shown in Figure 1 concerns the specification of a precursor molecule and a substrate. The selection of the system components is usually linked to available experiments. Common experimentally used substrate materials are, for example, SiO2, Si, Au

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

• electrical [57][58], chemical [59], optical [60][61], and mechanical [62][63] measurements. Results and Discussion Closed-loop KPFM measurements in two-pass PFT mode The new OL AM-KPFM implementation was tested on a commercially available sample consisting of large Au and Al metal regions deposited on a Si

• substrate (Bruker Nano Surfaces, Santa Barbara, CA, USA); the metal regions are separated by trenches that expose the Si substrate at their bottom. Figure 1a shows the AFM topographical image of one of these trenches, bordered by Au (left) and Al (right). The CPD maps over the sample were obtained first by

• coated probe (Bruker, Santa Barbara, CA, USA). A set of CPD maps over the same Au/Si/Al trench is shown in Figure 1d–g. As can be seen, the CPD contrast of the maps obtained by CL AM-KPFM changes with the position of the cantilever over either Au or Al (refer to Figure 1d–f) whereas the CPD maps from CL

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

• their sizes [92]. Generally, a QD-based EML is sandwiched between a polymer-based ETL and HTL. Carbon-based nanomaterials such as SWNT have also been investigated as EML in OLED. Firstly, a SWNT p–n junction on a Si substrate has been investigated by Lee et al. [93]. Further, Mueller et al., with some

Progress and innovation of nanostructured sulfur cathodes and metal-free anodes for room-temperature Na–S batteries

• Marina Tabuyo-Martínez,
• Bernd Wicklein and
• Pilar Aranda

Beilstein J. Nanotechnol. 2021, 12, 995–1020, doi:10.3762/bjnano.12.75

• to the expansion of these batteries into wider consumer markets, for which hard carbon, Si, Sn and Sb alloys, as well as phosphorous compounds are currently investigated [25][26][27]. This review focuses on the most recent designs of cathode materials for RT Na–S batteries, which attempt to overcome

• accommodated by the matrices, especially in the case of flexible ones. Na alloys and intermetallics Sodium is capable of forming alloys and intermetallic compounds with a range of elements at room temperature, most notably with Sb, Sn, P, Si, Ge, and Bi [73]. This way, considerable amounts of Na can be stored

• intermetallic compounds (M-Sn/Sb/P with M = Sn, Sb, P, Si, Bi, Cu, Ni, Fe, Zn). Fully sodiated Sb, Sn, and P form the phases Na3Sb, Na15Sn4, and Na3P, which offer theoretical capacities of 660, 847 and 2596 mAh·g−1, respectively [73]. However, the measured values are usually somewhat lower due to cycle

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

• p-type Si by measuring I–V and C–V characteristics. The fabricated Au/CuNiCoS4/p-Si device exhibited good rectifying properties, high photoresponse activity, low series resistance, and high shunt resistance. The C–V characteristics revealed that capacitance and conductance of the photodiode are

• voltage-and frequency-dependent. The fabricated device with CuNiCoS4 thiospinel nanocrystals can be employed in high-efficiency optoelectronic applications. Keywords: Au/CuNiCoS4/p-Si device; CuNiCoS4; optoelectronic applications; Schottky devices; Introduction Recently, spinel materials have attracted

• characteristics of the photodiode after inserting CuNiCoS4 nanocrystals as interlayer between Au metal and p-Si were investigated. The aim is to obtain more powerful photodiodes by using a new type of interlayer material. XRD, HR-TEM, and SEM analyses were carried out to characterize the thiospinel CuNiCoS4

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

• ][37][38][39], while also B deposition was shown to result in effective passivation of the Si surface [40][41]. In particular for electronic devices, oxidized semiconductor surfaces (e.g., silicon dioxide layers formed on bare silicon) are mostly used as substrates for fabricating devices [42]. Most of

• molecules from a semiconducting substrate is discussed for the example of both insulating CaF2 thin films on Si(111) [91] and hydrogen passivation of Ge(001) surfaces [92]. In the first case, three scenarios were compared: PTCDA on Si, on a thin CaF2, and on a thicker CaF2 layer. While isolated PTCDA

• molecules were pinned to defects on Si and also on the thin CaF2 layer, PTCDA was physically decoupled via the thicker CaF2 films and self-assembled into small islands. For FePc on H-passivated Ge(001), efficient physical decoupling facilitated the growth of large islands with upright oriented molecules

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 procedure for the controllable operation of devices based on S/F heterostructures. Samples We study two types of Nb/Co MLs with different numbers of F-layers and layer thicknesses. The simplest S1, Nb(50 nm)/Co(1.5 nm)/Nb(8 nm)/Co(2.5 nm)/Nb(8 nm)/Si ML (bottom-to-top), has just two dissimilar Co

• layers composing a single pseudo spin valve. A more complex S2, Nb(50 nm)/[Co(1.5 nm)/Nb(6 nm)/Co(2.5 nm)/Nb(6 mn)]3Co(1.5 nm)/Nb(6 nm)/Si (the structure in square brackets is repeated three times) has five Co layers. MLs are deposited by magnetron sputtering in a single deposition cycle without breaking

• the vacuum. We use a Nb target (99.95% purity) for deposition of S-layers, Co (99.95% purity) for F-layers, and Si (99.999%) for seeding bottom and protective top layers. MLs are grown on a Si(111) wafer. Prior to deposition, targets were precleaned by plasma-etching for 3 min and in addition for 1

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

• (STEM) images after nearest neighbor down-sampling. This enabled an increase in image resolution of up to 100-fold, decreasing scanning time and electron dose [120]. Another application of CNNs for STEM was for atomic defect classification [121]. The goal was to characterize defects related to Si

• was trained on simulated STEM images. Then, scanning tunneling microscopy (STM) images of the same sample were used to characterize the defects. STM images, which give the local density of states, measure not only the Si lattice, but also defect areas where this well-ordered lattice disappears. Such

• images were compared with those computed by density functional theory (DFT) based on well-known single and dimer Si defects. The examples given here demonstrate the utility of deep learning in general and CNN in particular in the field of microscopy. In the following section, the emphasis is narrowed

Silver nanoparticles nucleated in NaOH-treated halloysite: a potential antimicrobial material

• Yuri B. Matos,
• Rodrigo S. Romanus,
• Mattheus Torquato,
• Edgar H. de Souza,
• Rodrigo L. Villanova,
• Marlene Soares and
• Emilson R. Viana

Beilstein J. Nanotechnol. 2021, 12, 798–807, doi:10.3762/bjnano.12.63

• aluminosilicate sheet that folds over itself in virtue of the internal stress inherent to the crystalline structure of the material, forming nanotubes [25]. As shown in Figure 1, it folds with a silicate phase facing outwards (Si-O), and an aluminol phase facing inwards (Al-OH). Since the internal and external

• spacing” of the oxygen atoms is different for the two crystalline phases, straining them to conform the oxygen into both structures at the same time. It is our theory that as the NaOH chemical bath etches Al and Si atoms from HNT [31][32], internal sharing of apical oxygen is reduced, diminishing the

Reducing molecular simulation time for AFM images based on super-resolution methods

• Zhipeng Dou,
• Jianqiang Qian,
• Yingzi Li,
• Rui Lin,
• Jianhai Wang,
• Peng Cheng and
• Zeyu Xu

Beilstein J. Nanotechnol. 2021, 12, 775–785, doi:10.3762/bjnano.12.61

• Lennard–Jones (LJ) potential is used to describe the interaction between the graphene layers and the tip substrate. The LJ parameters for C–C are εC–C = 2.84 meV, σC–C = 0.34 nm and for Si–C the parameters are εSi–C = 8.909 meV, σSi–C = 0.3326 nm (ε is the depth of the potential well, σ is the finite

• distance). The cut-off distance for the C–C interaction is 1.19 nm. The cut-off distance for the Si–C interaction is changed to observe the impact on the simulation. Increasing the cut-off distance increases the number of atoms in the tip–sample interaction but the result is more accurate. For the gold

• substrate, the interaction between Au atoms is calculated by the embedded atom method (EAM) potential [56]. The LJ potential is employed to calculate the interaction between Si and Au (εSi–Au = 5.4297 meV, σSi–Au = 0.33801 nm). Due to the relatively large size of the substrate compared to the tip and a

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

• several articles reporting the photovoltaic effect for the n-type ZnO/p-type Si heterojunction [10][11][12][13][14]. In several works, open-circuit voltage (VOC), short-circuit current (JSC), fill factor (FF), and photovoltaic efficiency (Eff.) were reported for ZnO/Si solar cells. Such results were

• . = 6.7%) [13]. In our previous work, we reported JSC = 32 mA·cm−2; VOC = 470 mV; FF = 69%; Eff. = 10.5%, and JSC = 38 mA·cm−2; VOC = 520 mV; FF = 71%; Eff. = 14% for planar and textured Zn1−xMgxO/Si solar cells, respectively [14]. A solar efficiency of up to 14% was reported by us for structures grown on

• a 180 μm thick p-type Si substrate. Further cost reduction requires the use of a thinner Si substrate/absorber. Thus, in this paper we report photovoltaic results for a 50 μm thick Si absorber. Experimental Silicon preparation The p-type silicon wafer with thickness of 50 μm and a diameter of 5 cm

Recent progress in actuation technologies of micro/nanorobots

• Ke Xu and
• Bing Liu

Beilstein J. Nanotechnol. 2021, 12, 756–765, doi:10.3762/bjnano.12.59

• this, the new microrobot is expected to be used in targeted drug delivery and other biomedical fields. Si et al. [27] proposed a theoretical concept of a nanorobot consisting of a nanoparticle and four single-stranded DNAs placed on a quad-nanopore device for motion control. When an electric field is

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

• SiO2/Si substrate were irradiated on one half with 25 keV helium ions. It was found that at a dose of 2 × 1015 ions/cm2 a domain wall could be injected into the structure due to the introduction of lattice defects that locally reduced the perpendicular magnetic anisotropy. By raising the dose slightly

• were so low, the change in optical properties was attributed to the local accumulation of defects (as opposed to collisional phase mixing). In a plasmonic application, resonant triangular nanostructures were created in a graphene sheet supported on SiO2/Si by selectively irradiating the graphene in the

• ]. Here, neon line irradiation of an Si(25 nm)/SiO2(6.5 nm)/Si(bulk) stack was used to induce collisional mixing of silicon atoms into the buried SiO2 layer. Upon subsequent thermal annealing, 1D chains of silicon nanocrystals of 2.2 nm diameter self-assembled in the center of the SiO2 layer. A TEM-based

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

• ; gallium arsenide; photovoltaics; surface passivation; Introduction The atomic layer deposition (ALD) method is used for silicon passivation in photovoltaics. In recent years we proposed the usage of ALD for the construction of simplified Si-based cells [1]. Once zinc oxide (ZnO) nanorods were employed as

Spontaneous shape transition of Mn_xGe_1−x islands to long nanowires

• S. Javad Rezvani,
• Luc Favre,
• Gabriele Giuli,
• Yiming Wubulikasimu,
• Isabelle Berbezier,
• Augusto Marcelli,
• Luca Boarino and
• Nicola Pinto

Beilstein J. Nanotechnol. 2021, 12, 366–374, doi:10.3762/bjnano.12.30

• Ge on Si substrates, or the endotaxial growth of transitional metal silicides (e.g., CoSi2) [34][36]. In these studies, the NWs exhibit a narrow diameter distribution, in contrast to those obtained by VLS, which commonly have wider range due to the droplet size distribution. In the present work, we

• epilayer and the substrate as detected in several heteroepitaxial systems, such as Ge on Si [42][43][44], InAs on GaAs [45], Co silicide [36], and silicides with different metals [35]. Such a mechanism is expected to occur in our Mn layers deposited on Ge(111) substrates, due to the large lattice mismatch

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

• of the samples by depleting the films of oxygen. Figure 2 shows the general oxide spectra for three SiO2 samples. The high-resolution (HR) analysis of the Si 2p3 and O 1s spectra recorded [43][44] for the SiO2 samples are shown in Figure 3. Using this analysis, we determined the elemental composition

• as well as the chemical and electronic states of the elements that exist in the SiO2 films. Although Si 2p3 shows small chemical changes, the binding energy value of 103.7 eV indicates a completely oxidized Si for the SiO2 films (Figure 3a) [43][44][45][46]. Experimental data reveal that there is

• measured thickness values for the oxide films are shown in Table 2 and they are found to be similar to the predefined ones. The EDS distribution in all investigated samples showed the presence of chemical elements such as Zn L, Si K, and O K (Table 2). In the case of the 200 nm thick SiO2 sample, the

The nanomorphology of cell surfaces of adhered osteoblasts

• Christian Voelkner,
• Mirco Wendt,
• Regina Lange,
• Max Ulbrich,
• Martina Gruening,
• Susanne Staehlke,
• Barbara Nebe,
• Ingo Barke and
• Sylvia Speller

Beilstein J. Nanotechnol. 2021, 12, 242–256, doi:10.3762/bjnano.12.20

• osteoblast after 3 h of adhesion to titanium. The ruffles on the cell membrane are visible. (FE-SEM SUPRA25, 1 kV, 30° angle, 100 nm Ti on Si wafer, fixation by 2.5% glutardialdehyde (GA), acetone series, critical point drying). Edge height analysis. (a) Topography of a fixed osteoblast on a 10 nm Au layer

Extended iron phthalocyanine islands self-assembled on a Ge(001):H surface

• Rafal Zuzak,
• Marek Szymonski and
• Szymon Godlewski

Beilstein J. Nanotechnol. 2021, 12, 232–241, doi:10.3762/bjnano.12.19

• the passivation of semiconducting materials, which removes surface dangling bonds and significantly reduces surface reactivity, may also provide a sufficiently insulating layer for an efficient decoupling of molecular structures from the substrate influence. Among such surfaces, hydrogen-passivated Si

• (001):H [22][23], Si(111):H [24], and Ge(001):H [25][26][27][28] surfaces are most commonly mentioned. Iron phthalocyanines (FePc) have been studied on Si(111):H [24] and it was concluded that the molecules are weakly coupled to the substrate. Interestingly, in another study, it has been reported that

• FePc molecules deposited at room temperature on Si(111):H serve as sources of single Fe atoms and undergo de-metalation [29]. Importantly, hydrogen-passivated Si/Ge surfaces may also act as platforms for nanostructurization by the atomically precise desorption of individual hydrogen atoms and the

A review on the biological effects of nanomaterials on silkworm (Bombyx mori)

• Sandra Senyo Fometu,
• Guohua Wu,
• Lin Ma and
• Joan Shine Davids

Beilstein J. Nanotechnol. 2021, 12, 190–202, doi:10.3762/bjnano.12.15

• -doped carbon dots (C-NCDs), and to 0.39 µg/µL of Si NPs in order to study the differences in the immune responses and programmed cell death induced in hemocytes [153]. It was shown that autophagy and apoptosis caused by Si NPs were reverted and experimental groups exposed to C-NCDs, CdTe QDs caused

• autophagy, apoptosis, and necrosis in the hemocytes. Xing et al. [154] studied the outcome of introducing Si NPs in the hemolymph of the silkworm. It was reported that 3.9 µg of Si NPs was toxic to the hemocytes when compared to the groups exposed to 0.39 and 0.039 µg of Si NPs. A high dose of Si NPs (3.9

• of nanomaterials, such as Ag NPs, CdTe QDs, and Si NPs have shown to induce an excessive production of ROS, which causes oxidative stress leading to cell apoptosis and autophagy. This review also discussed the effects of nanomaterials on the silk fibers. Reports indicate that the presence of these

ZnO and MXenes as electrode materials for supercapacitor devices

• Ameen Uddin Ammar,
• Ipek Deniz Yildirim,
• Feray Bakan and
• Emre Erdem

Beilstein J. Nanotechnol. 2021, 12, 49–57, doi:10.3762/bjnano.12.4

• large family of hexagonal layered ternary transition-metal carbides, carbonitrides, and nitrides with the formula: Mn+1AXn where M denotes a transition metal (Sc, Ti, V, Cr, Zr, Nb, Mo, Hf, or Ta), A denotes a group-13 or group-14 element (Al, Si, P, S, Ga, Ge, As, Cd, Ln, Sn, Tl, or Pb), and X denotes

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

• , and water and dried in a stream of argon. Si(100) wafers with a 300 nm thick thermal oxide layer (Silicon Quest International, USA) were treated successively with acetone/ethanol/water. Al2O3 films were grown by using an ALD system R200 (Picosun, Finland) in the thermal mode with varying numbers of

• values of 5 and 10 nm, the remaining thickness of the Al2O3 film on FTO was in the range of 7–8 nm. This suggests that during the 5 min exposure to 1 M NaOH, approx. 9–10 nm of the ALD film was dissolved, which corresponds to a dissolution rate of approx. 108–120 nm/h. When a Si/SiO2 wafer coated with

• (CN)6] in 0.5 M KCl demonstrating the blocking properties of 17 nm thick Al2O3 films on FTO before and after exposure to 1 M NaOH for 5 or 60 min compared to uncovered FTO. The scan rate is 50 mV/s. Si wafer coated with an Al2O3 film (17 nm) after exposure to 1 M NaOH for 1h. (a) Optical microscopy

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

Piezotronic effect in AlGaN/AlN/GaN heterojunction nanowires used as a flexible strain sensor

• Jianqi Dong,
• Liang Chen,
• Yuqing Yang and
• Xingfu Wang

Beilstein J. Nanotechnol. 2020, 11, 1847–1853, doi:10.3762/bjnano.11.166

• substrate, followed by a 500 nm layer of Si-doped N-GaN (the doping concentration was 5 × 1018·cm−3). The thickness of the heavily doped GaN was 1.5 μm and the Si doping concentration was 1.0 × 1019·cm−3. The thickness of the two thin N++-GaN layers was only 10 nm each with a Si concentration of 4.5 × 1019

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

• °C, urea hydrolysis took place reducing the nickel precursor to nickel species, which diffused into the silica layers through the mesoporous shell. The nickel species reacted with the surface hydroxides to give nickel phyllosilicate via a Ni–O–Si polymerization reaction. TiO2 (dTiO2 = 30 ± 9 nm) was

• spectroscopy is a useful technique to determine the functional groups present in the silica and nickel phyllosilicate nanomaterials. Figure S2c in Supporting Information File 1 shows infrared absorption peaks of mSiO2 and mSiO2@NiPS at 813 and 1073 cm−1, characteristic of Si–O symmetric stretching and

• asymmetric stretching modes in silica and silicates [49][54]. It was difficult to specify the Si–O–Si stretching bands that are distinct for 1:1 nickel phyllosilicate, due to the broad band observed at 950–1100 cm−1, which also represents the band position for Si–O–Si in silica. In the wavenumber region of