Transition from freestanding SnO₂ nanowires to laterally aligned nanowires with a simulation-based experimental design

• Jasmin-Clara Bürger,
• Sebastian Gutsch and
• Margit Zacharias

Beilstein J. Nanotechnol. 2020, 11, 843–853, doi:10.3762/bjnano.11.69

• experiments in order to switch freestanding nanowire growth to a laterally aligned growth mode. By means of finite element simulations, we determined that a higher volumetric flow and a reduced process pressure will result in a preferred laterally aligned nanowire growth. Furthermore, increasing the

• Sn gas was achieved by a carbothermal reduction of SnO2 powder. However, we observed no elongation of the nanowire length with an increase of the process time. Nevertheless, an alternating gas exchange between an inert gas (Ar) and an oxygen-containing process atmosphere yielded an elongation of the

• laterally aligned nanowires, indicating that the nanowire growth takes place in a transient period of the gas exchange. Keywords: finite element method simulation; laterally aligned nanowires; planar growth; tin oxide; vapor–liquid–solid nanowire growth; Introduction Since the first reports in 1964 by

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

• Atasi Chatterjee,
• Christoph Tegenkamp and
• Herbert Pfnür

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

• corresponds to characteristic decrements of conductance. It can be interpreted by the semi-classical Sharvin formula. This formula is an approximation for contacts approaching the ballistic regime. Within this model, the nanowire conductance for a circular cross-sectional area, A, is given by [21]: with the

High-performance asymmetric supercapacitor made of NiMoO₄ nanorods@Co₃O₄ on a cellulose-based carbon aerogel

• Meixia Wang,
• Jing Zhang,
• Xibin Yi,
• Benxue Liu,
• Xinfu Zhao and
• Xiaochan Liu

Beilstein J. Nanotechnol. 2020, 11, 240–251, doi:10.3762/bjnano.11.18

• construction of an integrated hierarchical porous nanoarchitecture by combining two metal oxides is a brilliant way to greatly enhance the overall electrochemical performance owing to synergistic effects [20]. For example, Li et al. synthesized 3D hybrid Co3O4/NiMoO4 nanowire/nanosheet arrays on a carbon cloth

• , which exhibited a capacitance of 3.6 F/cm2 at 3 mA/cm2, a capacitance retention of 82% and an increase of the current density from 3 to 15 mA/cm2 [21]. Cai et al. reported a facile two-step hydrothermal method to synthesize unique 3D Co3O4/NiMoO4 core/shell nanowire arrays on Ni foam, and the resulting

Molecular architectonics of DNA for functional nanoarchitectures

• Debasis Ghosh,
• Lakshmi P. Datta and
• Thimmaiah Govindaraju

Beilstein J. Nanotechnol. 2020, 11, 124–140, doi:10.3762/bjnano.11.11

• template for nanowire synthesis. The miniaturization of devices is of central importance in electronics and has galvanized significant research in materials science. The need for the miniaturization of devices at the nanoscale interface has led to the exploration of new material systems and building blocks

Abrupt elastic-to-plastic transition in pentagonal nanowires under bending

• Sergei Vlassov,
• Magnus Mets,
• Boris Polyakov,
• Jianjun Bian,
• Leonid Dorogin and
• Vahur Zadin

Beilstein J. Nanotechnol. 2019, 10, 2468–2476, doi:10.3762/bjnano.10.237

• are described by the widely used embedded atom method (EAM), and a potential for Ag is utilized here [36]. Due to the limitation of computational resources, the size of the nanowire in simulation is much smaller than that in the experiments. Figure 2a shows the atomic configuration of the penta

• showed that coating can increase the bending strength of the NWs. Schematic and SEM image of a pentagonal silver nanowire (Ag NW). SEM image adapted with permission from [28], copyright 2013 Elsevier. (a) Atomic simulation model of the Ag NW, (b) the internal twin structures (atoms in perfect lattice and

Deterministic placement of ultra-bright near-infrared color centers in arrays of silicon carbide micropillars

• Stefania Castelletto,
• Abdul Salam Al Atem,
• Faraz Ahmed Inam,
• Hans Jürgen von Bardeleben,
• Sophie Hameau,
• Ahmed Fahad Almutairi,
• Gérard Guillot,
• Shin-ichiro Sato,
• Alberto Boretti and
• Jean Marie Bluet

Beilstein J. Nanotechnol. 2019, 10, 2383–2395, doi:10.3762/bjnano.10.229

• nanowire detector with 80% quantum efficiency, and the DWF is 5%. The ZFS is 1.2–1.4 GHz in the ground state and 0.75–0.95 GHz in excited states. Both VSi and VSiVC have been proved to be useful for a high-fidelity spin–photon interface [6][27]. PL spectroscopy and EPR measurements combined with ab initio

Nitrogen-vacancy centers in diamond for nanoscale magnetic resonance imaging applications

• Alberto Boretti,
• Lorenzo Rosa,
• Jonathan Blackledge and
• Stefania Castelletto

Beilstein J. Nanotechnol. 2019, 10, 2128–2151, doi:10.3762/bjnano.10.207

• allowed for in vivo imaging on the single-biomolecular scale at room temperature [12]. Other approaches not based on NV centers are evolving at the same pace as methods based on NV centers. For example, a new method for high-resolution nano-MRI coupling high spin sensitivity of nanowire-based MR detection

Prestress-loading effect on the current–voltage characteristics of a piezoelectric p–n junction together with the corresponding mechanical tuning laws

• Wanli Yang,
• Shuaiqi Fan,
• Yuxing Liang and
• Yuantai Hu

Beilstein J. Nanotechnol. 2019, 10, 1833–1843, doi:10.3762/bjnano.10.178

• ] studied the static extensional behavior of a piezoelectric semiconductor nanofiber. Liang et al. [20] analyzed the fundamental characteristics of a cantilevered ZnO nanowire exposed to a transient end force. Recently, Fan et al. [21] and Zhang et al. [22] revisited the bending behavior of a cantilevered

• ZnO nanowire based on the linear phenomenological theory of piezoelectric semiconductors. In their studies, the electric leakage of a bent ZnO nanowire is connected to the semiconductor properties and concluded that a lower doping concentration is more suitable for a bent ZnO nanowire to harvest

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

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

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

• nanowire array embedded in an insulator matrix, and to properly disentangle the electronic properties of both structures a technique with nanoscale resolution is needed. Indeed with the use of the LC-AFM technique, the conductivity of the developed nanostructures at the nanoscale can be characterized

• , providing the possibility of obtaining current maps as well as I–V characteristics at a given spot. Figure 2a and Figure 2b show the topography and current maps of the TiO nanowire network on SrTiO3(100). TiO has a higher conductivity than the surrounding SrTiO3 (STO) surface (the no current areas at

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

Selective gas detection using Mn₃O₄/WO₃ composites as a sensing layer

• Yongjiao Sun,
• Zhichao Yu,
• Wenda Wang,
• Pengwei Li,
• Gang Li,
• Wendong Zhang,
• Lin Chen,
• Serge Zhuivkov and
• Jie Hu

Beilstein J. Nanotechnol. 2019, 10, 1423–1433, doi:10.3762/bjnano.10.140

• gas sensing performance. Actually, the precursors before calcination are nanowire-like (Supporting Information File 1, Figure S1), but they present nanoparticles or nanorods after calcination treatment. The process could be explained by the re-crystallization of WO3 when annealing in air atmosphere

Gas sensing properties of individual SnO₂ nanowires and SnO₂ sol–gel nanocomposites

• Alexey V. Shaposhnik,
• Dmitry A. Shaposhnik,
• Sergey Yu. Turishchev,
• Olga A. Chuvenkova,
• Stanislav V. Ryabtsev,
• Alexey A. Vasiliev,
• Xavier Vilanova,
• Francisco Hernandez-Ramirez and
• Joan R. Morante

Beilstein J. Nanotechnol. 2019, 10, 1380–1390, doi:10.3762/bjnano.10.136

• sensor response due to the unlikelihood of sample recrystallization. The results from the ammonia detection experiments showed that the ratio of the sensor response to the surface area exhibits similar values for both the individual nanowire and nanopowders-based sensor materials. Keywords: gas sensors

• mainstream process in sensor development, because researchers have reached the limits of this method. For this reason, the interest in the development of nanowire devices (i.e., quasi-1-dimensional objects) has increased. Their surface-to-volume ratio can be as high as that of nanopowders obtained from

• nanowire synthesis was developed and reported in detail in the classic work of R. Wagner and W. Ellis [1]. Recently, with the use of this method, SnO2, In2O3, WO3, ZnO and other metal oxide nanowires were obtained [1][2][3][4][5]. Liquid phase synthesis methods have also been widely implemented [6][7][8][9

Janus-micromotor-based on–off luminescence sensor for active TNT detection

• Ye Yuan,
• Changyong Gao,
• Daolin Wang,
• Chang Zhou,
• Baohua Zhu and
• Qiang He

Beilstein J. Nanotechnol. 2019, 10, 1324–1331, doi:10.3762/bjnano.10.131

• ][17][18][19][20]. Based on the concept of nanoarchitectonics [21][22], various kinds of micro/nanomotors have been fabricated, such as Janus capsule micromotors [23], tubular micromotors [24], helical nanomotors [25], nanowire motors [26], and nanorod motors [27]. Unlike inert particles that move by

Electroluminescence and current–voltage measurements of single-(In,Ga)N/GaN-nanowire light-emitting diodes in a nanowire ensemble

• David van Treeck,
• Johannes Ledig,
• Gregor Scholz,
• Jonas Lähnemann,
• Mattia Musolino,
• Abbes Tahraoui,
• Oliver Brandt,
• Andreas Waag,
• Henning Riechert and
• Lutz Geelhaar

Beilstein J. Nanotechnol. 2019, 10, 1177–1187, doi:10.3762/bjnano.10.117

• ) behavior of single, freestanding (In,Ga)N/GaN nanowire (NW) light-emitting diodes (LEDs) in an unprocessed, self-assembled ensemble grown by molecular beam epitaxy. The data were acquired in a scanning electron microscope equipped with a micromanipulator and a luminescence detection system. Single NW

• employed here a very powerful analysis tool. Keywords: electroluminescence; external quantum efficiency (EQE); nanowire LED; single nanowire; current–voltage; Introduction Group-III nitride nanowire (NW) ensembles have been employed for a wide range of applications, especially optoelectronic devices [1

• . However, with this approach they could not measure the currents in the investigated NWs. Here, we present simultaneous measurements of the I–V behavior as well as the EL of single, freestanding nanowire LEDs in a self-assembled NW ensemble. To this end, as-grown NWs are contacted without any further

Renewable energy conversion using nano- and microstructured materials

• Harry Mönig and
• Martina Schmid

Beilstein J. Nanotechnol. 2019, 10, 771–773, doi:10.3762/bjnano.10.76

• benefits arising from core–shell nanowire arrays for Si heterojunction solar cells. Contacts with a high surface-to-volume ratio can clearly be seen. Particularly in photovoltaics, they may be prone to increased recombination losses. For other applications, such as water splitting, porous materials may

Gold nanoparticles embedded in a polymer as a 3D-printable dichroic nanocomposite material

• Lars Kool,
• Anton Bunschoten,
• Aldrik H. Velders and
• Vittorio Saggiomo

Beilstein J. Nanotechnol. 2019, 10, 442–447, doi:10.3762/bjnano.10.43

• dependent study shows the formation of small gold nuclei that in time cluster together forming nanowire-like structures concomitant to the first color change. The second change of color, from ink-black to purple, is accompanied by an enhancement of the scattering, giving the purple solution a brown

Sub-wavelength waveguide properties of 1D and surface-functionalized SnO₂ nanostructures of various morphologies

• Venkataramana Bonu,
• Binaya Kumar Sahu,
• Arindam Das,
• Sankarakumar Amirthapandian,
• Sandip Dhara and
• Harish C. Barshilia

Beilstein J. Nanotechnol. 2019, 10, 379–388, doi:10.3762/bjnano.10.37

• measurements and a band diagram is proposed. Keywords: functionalization; nanowires; photoluminescence; SnO2; sub-wavelength waveguide; Introduction The development and understanding of one-dimensional (1D) nanowire (NW) sub-wavelength waveguides is a crucial step towards on-chip routing of optical signals

• measurements. The NWs were excited at 325 nm to observe the waveguide nature. Optical images were captured for the nanowire waveguides using the same optical microscope attached to the micro-Raman set up. We used a 50× objective for capturing images with numerical aperture (NA) of 0.45. The images were saved

Geometrical optimisation of core–shell nanowire arrays for enhanced absorption in thin crystalline silicon heterojunction solar cells

• Robin Vismara,
• Olindo Isabella,
• Andrea Ingenito,
• Fai Tong Si and
• Miro Zeman

Beilstein J. Nanotechnol. 2019, 10, 322–331, doi:10.3762/bjnano.10.31

• characteristic radial junction configuration can lead to higher device performance, by increasing light absorption and, at the same time, improving the collection efficiency of photo-generated charge carriers. This work investigates the performance of ultra-thin solar cells characterised by nanowire arrays on a

• crystalline silicon bulk. Results: Proof-of-concept devices on a p-type mono-crystalline silicon wafer were manufactured and compared to flat references, showing improved absorption of light, while the final 11.8% (best-device) efficiency was hindered by sub-optimal passivation of the nanowire array. A

• dependence of absorption on the nanowire cross section, a weaker effect of the nanowire height and good resilience for angles of incidence of light up to 60°. Conclusion: The presence of a nanowire array increases the optical performance of ultra-thin crystalline silicon solar cells in a wide range of

Electromagnetic analysis of the lasing thresholds of hybrid plasmon modes of a silver tube nanolaser with active core and active shell

• Denys M. Natarov,
• Trevor M. Benson and
• Alexander I. Nosich

Beilstein J. Nanotechnol. 2019, 10, 294–304, doi:10.3762/bjnano.10.28

• cyclic photonic molecules [22][23], active circular disks with passive annular Bragg reflectors [24], and partially active circular and elliptic cavities [25][26]. More recently the LEP was applied to the modes of a single plasmonic nanowire [5] and a single plasmonic nanostrip [8] placed into an active

• highest red-shift, followed by the higher-order modes of the same type, and etc. If the tube gets thicker, each of the emission wavelengths of these modes moves closer to the value of 359 nm (from the red side) that is the accumulation point for the modes of the solid circular silver nanowire placed in

Charged particle single nanometre manufacturing

• Philip D. Prewett,
• Cornelis W. Hagen,
• Claudia Lenk,
• Steve Lenk,
• Marcus Kaestner,
• Tzvetan Ivanov,
• Ahmad Ahmad,
• Ivo W. Rangelow,
• Xiaoqing Shi,
• Stuart A. Boden,
• Alex P. G. Robinson,
• Dongxu Yang,
• Sangeetha Hari,
• Marijke Scotuzzi and
• Ejaz Huq

Beilstein J. Nanotechnol. 2018, 9, 2855–2882, doi:10.3762/bjnano.9.266

• technique and to determine the ultimate process resolution. In one of their early papers, Toth and Lobo [94] suggested that the etching was driven by SEs generated at the surface of the deposit or the substrate. Based on this, they demonstrated the fabrication of 4–7 nm wide gaps in a carbonaceous nanowire

• by an unconventional method. Using a stationary beam, pits were first etched at the desired location by EBIE with H2O in an environmental scanning electron microscope (ESEM). The field of view containing the nanowire was then scanned repeatedly in the presence of the precursor until a gap was created

• due to the increased SE yield from the nanowire sidewalls. The enhanced contrast of the nanowire edges seen in the SE image lends support to their theory. The advantage of working in an ESEM was the possibility of charge counteraction, allowing the use of insulating substrates like SiO2 that are

Improved catalytic combustion of methane using CuO nanobelts with predominantly (001) surfaces

• Qingquan Kong,
• Yichun Yin,
• Bing Xue,
• Yonggang Jin,
• Wei Feng,
• Zhi-Gang Chen,
• Shi Su and
• Chenghua Sun

Beilstein J. Nanotechnol. 2018, 9, 2526–2532, doi:10.3762/bjnano.9.235

• in an early study [21][23], CuO NWs or NBs having predominantly (001) surfaces can be obtained when Cu(OH)2 is employed as a nanowire precursor for decomposition. The mechanism of shape-reserved transformation from Cu(OH)2 to CuO has been previously discussed in the literature [24][25][26]. Prior to

Thickness-dependent photoelectrochemical properties of a semitransparent Co₃O₄ photocathode

• Malkeshkumar Patel and
• Joondong Kim

Beilstein J. Nanotechnol. 2018, 9, 2432–2442, doi:10.3762/bjnano.9.228

• ]. Existing studies have measured a photocurrent of 33.6 μA·cm−2 in 0.5 M Na2S on a mesoporous Co3O4 nanosheet grown through in situ transformation from hexagonal Co(OH)2 to spinel Co3O4 [18]. Hong et al. demonstrated a photocurrent of 0.4 mA·cm−2 from Co3O4 nanowire photocathodes, which could be enhanced to

Magnetism and magnetoresistance of single Ni–Cu alloy nanowires

• Andreea Costas,
• Camelia Florica,
• Elena Matei,
• Maria Eugenia Toimil-Molares,
• Ionel Stavarache,
• Andrei Kuncser,
• Victor Kuncser and
• Ionut Enculescu

Beilstein J. Nanotechnol. 2018, 9, 2345–2355, doi:10.3762/bjnano.9.219

• modeling. It has been theoretically proven that the proposed methodology can be applied over a large range of nanowire diameters if the measurement geometry is suitably chosen. Keywords: nanowires; magnetic properties; magnetoresistance; Introduction Nowadays, due to the continuous search for new

• electrons can be easily tuned via the nanowire composition. However, an anisotropy magneto-resistance (AMR) mechanism would be expected for such systems instead of GMR. As a direct consequence, this much weaker effect can no longer be detected in arrays of nanowires but only in single nanowires. Magneto

• purpose of all these specific methods is to have a good and simultaneous control of morphology, structure and composition in order to succeed in tailoring the magnetic properties of the nanowires. A very useful technique to fabricate nanowire arrays is electrochemical deposition inside nanoporous

Intrinsic ultrasmall nanoscale silicon turns n-/p-type with SiO₂/Si₃N₄-coating

• Dirk König,
• Daniel Hiller,
• Noël Wilck,
• Birger Berghoff,
• Merlin Müller,
• Sangeeta Thakur,
• Giovanni Di Santo,
• Luca Petaccia,
• Joachim Mayer,
• Sean Smith and
• Joachim Knoch

Beilstein J. Nanotechnol. 2018, 9, 2255–2264, doi:10.3762/bjnano.9.210

• states (DOS) when embedded in SiO2 or Si3N4. We use further h-DFT results of a Si-nanowire (NWire) covered in SiO2 and Si3N4 to examine the device behaviour of an undoped Si-NWire FET based solely on CMOS-compatible materials (e.g., Si, SiO2, Si3N4) using the nonequilibrium Green’s function (NEGF

• results of Si-NWires. The simulations are based on a self-consistent solution of the Poisson and Schrödinger equations on a finite difference grid. A one-dimensional, modified Poisson equation is considered here that provides an adequate description of the electrostatics of wrap-gate nanowire transistors

• related to Si-NWires and Si-NCs to scale 1/2/3 for NWells/NWires/NCs [14]. This relation explains why larger ΔE values for HOMOs and LUMOs are obtained for Si-NWires (Figure 6) as compared to Si-NWells (Figure 5b). Concept of undoped Si nanowire FETs With the ΔE values of the usn-Si coated with SiO2 vs

Optimization of the optical coupling in nanowire-based integrated photonic platforms by FDTD simulation

• Nan Guan,
• Andrey Babichev,
• Martin Foldyna,
• Dmitry Denisov,
• François H. Julien and
• Maria Tchernycheva

Beilstein J. Nanotechnol. 2018, 9, 2248–2254, doi:10.3762/bjnano.9.209

• , Russia LPICM-CNRS, Ecole Polytechnique, Université Paris-Saclay, 91128 Palaiseau, France, Saint Petersburg Electrotechnical University "LETI", ul. Professora Popova 5, 197376 Saint Petersburg, Russia 10.3762/bjnano.9.209 Abstract The optimized design of a photonic platform based on a nanowire light

• emitting diode (LED) and a nanowire photodetector connected with a waveguide is proposed. The light coupling efficiency from the LED to the detector is optimized as a function of the geometrical parameters of the system using the finite difference time domain simulation tool Lumerical. Starting from a

• design reported in the literature with a coupling efficiency of only 8.7%, we propose an optimized photonic platform with efficiency reaching 65.5%. Keywords: FDTD modeling; nanowire LED; nitride nanowires; photonic integrated circuit; photonic platform; SiN/InGaN co-integration; visible light

Interaction-induced zero-energy pinning and quantum dot formation in Majorana nanowires

• Samuel D. Escribano,
• Alfredo Levy Yeyati and
• Elsa Prada

Beilstein J. Nanotechnol. 2018, 9, 2171–2180, doi:10.3762/bjnano.9.203

• reach the ballistic limit [12][13][14]. In spite of these advances, the experimental signatures of MBSs in the nanowire devices deviate significantly in several aspects from the theoretical predictions of minimal models. This is the case, for instance, regarding the behavior of the subgap conductance

• through the proximitized nanowire, which has been addressed in several experiments [10][12][13][14][15][16][17][18][19]. In a long wire (the length of which is much greater than the induced coherence length) the presence of MBSs manifests itself in the appearance of a zero-bias conductance peak the width

• magnetic effects [31], Coulomb repulsion among the carriers in the nanowire [22], or the presence of the normal drain lead connected to the hybrid wire [32]. Another source of Majorana oscillation suppression was put forward by some of us in a recent work [33]. The key realization is that MBSs in a finite