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

Localized photodeposition of catalysts using nanophotonic resonances in silicon photocathodes

• Evgenia Kontoleta,
• Sven H. C. Askes,
• Lai-Hung Lai and
• Erik C. Garnett

Beilstein J. Nanotechnol. 2018, 9, 2097–2105, doi:10.3762/bjnano.9.198

• adjusting the excitation wavelength from red to green to white, or (not shown) the nanostructure shape. (a) SEM images of a silicon nanocone (left), an inverted nanocone (middle) and a nanowire (right) coated with an 18 nm TiO2 layer. The tapering angle was controlled by varying the Cl2 and HBr/O2 flow

• deposited particle (100 pA beam current, 10 kV acceleration beam voltage). (a) Overlay images of backscattered electron (red) and secondary-electron (grey) SEM images after photo-electrodeposition of platinum on a silicon nanocone (left), inverted nanocone (middle), and nanowire (right). (b, c) Total amount

Electromigrated electrical optical antennas for transducing electrons and photons at the nanoscale

• Arindam Dasgupta,
• Mickaël Buret,
• Nicolas Cazier,
• Marie-Maxime Mennemanteuil,
• Reinaldo Chacon,
• Kamal Hammani,
• Jean-Claude Weeber,
• Juan Arocas,
• Laurent Markey,
• Gérard Colas des Francs,
• Alexander Uskov,
• Igor Smetanin and
• Alexandre Bouhelier

Beilstein J. Nanotechnol. 2018, 9, 1964–1976, doi:10.3762/bjnano.9.187

• connected tunneling optical antennas is fabricated by electron-beam lithography, Au evaporation and lift-off process. The structures consist of either a gold nanowire of 1.1 μm length and 130 nm width or a constriction as discussed above. For both types, the structures are connected to a set of electrodes

• . The thickness of the nanowire and electrodes is 50 nm, including a 5 nm Ti adhesion layer. The third step is the dry etching of the TiO2 layer. For that, we first create an etching mask by electron-beam lithography, thermal deposition of a 30 nm thick nickel layer and lift-off. Reactive ion etching is

• electromigrating in situ the nanowire to create the optical tunneling gap antenna. Figure 6a,c,e illustrates the experiment with different waveguide geometries and gap orientations. In Figure 6a, the TiO2 waveguide is 85 nm thick and 1.5 μm wide, and the SEM image was taken before the electromigration of the

A differential Hall effect measurement method with sub-nanometre resolution for active dopant concentration profiling in ultrathin doped Si_1−xGe_x and Si layers

• Richard Daubriac,
• Emmanuel Scheid,
• Hiba Rizk,
• Richard Monflier,
• Sylvain Joblot,
• Rémi Beneyton,
• Pablo Acosta Alba,
• Sébastien Kerdilès and
• Filadelfo Cristiano

Beilstein J. Nanotechnol. 2018, 9, 1926–1939, doi:10.3762/bjnano.9.184

• nanowire diameters of about 10 nm, a dopant deactivation is observed due to the dielectrical mismatch between the silicon and its surroundings. However, our previous investigations on 5 nm thick SiGeOI layers doped by ion implantation and activated by conventional rapid thermal annealing (RTA) [39][40

Nonlinear effect of carrier drift on the performance of an n-type ZnO nanowire nanogenerator by coupling piezoelectric effect and semiconduction

• Yuxing Liang,
• Shuaiqi Fan,
• Xuedong Chen and
• Yuantai Hu

Beilstein J. Nanotechnol. 2018, 9, 1917–1925, doi:10.3762/bjnano.9.183

• effect on the performance of a ZnO nanogenerator was investigated in detail and it was elucidated that carrier motion/redistribution occurs in the ZnO nanowire (ZNW) cross section while there is no carrier motion in the axial direction. At the same time, we noted that the amplitude of boundary electric

• power was analyzed in detail. The electrode size for the optimal performance of a ZnO nanowire generator was proposed. This analysis that couples electromechanical fields and carrier concentration as a whole has some referential significance to piezotronics. Keywords: carrier drift; crystallogrpahic c

• nanowire bent when an atomic force microscopy tip scans over the top of the nanowire. The electromechanical coupling converts mechanical energy into electric energy [28][29]. A piezoelectric potential is built inside the nanowire with the stretched side being positively charged and the compressed side

Josephson effect in junctions of conventional and topological superconductors

• Alex Zazunov,
• Albert Iks,
• Miguel Alvarado,
• Alfredo Levy Yeyati and
• Reinhold Egger

Beilstein J. Nanotechnol. 2018, 9, 1659–1676, doi:10.3762/bjnano.9.158

• end states. Using Green’s function techniques, the topological superconductor is alternatively described by the low-energy continuum limit of a Kitaev chain or by a more microscopic spinful nanowire model. We show that for the simplest S–TS tunnel junction, only the s-wave pairing correlations in a

• spinful TS nanowire model can generate a Josephson effect. The critical current is much smaller in the topological regime and exhibits a kink-like dependence on the Zeeman field along the wire. When a correlated quantum dot (QD) in the magnetic regime is present in the junction region, however, the

• ] have pointed out that the physics of the Kitaev chain could be realized in spin–orbit coupled nanowires with a magnetic Zeeman field and in the proximity to a nearby s-wave superconductor. The spinful nanowire model of references [2][3] indeed features p-wave pairing correlations for appropriately

Spatial Rabi oscillations between Majorana bound states and quantum dots

• Jun-Hui Zheng,
• Dao-Xin Yao and
• Zhi Wang

Beilstein J. Nanotechnol. 2018, 9, 1527–1535, doi:10.3762/bjnano.9.143

• candidate is the hybrid system of a spin–orbit-coupling nanowire and a conventional superconductor. Robust zero-bias conductance peak was first reported in this system, which originates from the self-conjugate nature of Majorana bound states and therefore was wildly recognized as a signature. An exotic

• fractional Josephson effect was also studied in the nanowire Josephson junctions, where novel Shapiro steps and Josephson radiations have been reported. Recently, the Coulomb blockade spectroscopy was exploited on finite-size nanowire segments that form nanowire islands with two Majorana bound states

• oscillation between the quantum dots and the Majorana bound states [29] and to investigate the self-conjugateness and exponential protection of Majorana bound states. In recent experiments, a hybrid structure of a quantum dot and a one-dimensional topological superconductor nanowire has been realized [36

Robust topological phase in proximitized core–shell nanowires coupled to multiple superconductors

• Tudor D. Stanescu,
• Anna Sitek and
• Andrei Manolescu

Beilstein J. Nanotechnol. 2018, 9, 1512–1526, doi:10.3762/bjnano.9.142

• promising involving semiconductor-superconductor hybrid systems [5][6][7][8][9]. The basic idea [10][11][12][13] is to proximity-couple a semiconductor nanowire with strong Rashba-type spin-orbit coupling (e.g., InSb or InAs) to a standard s-type superconductor (e.g., NbTiN or Al) in the presence of a

• longitudinal magnetic field. The system is predicted to host zero-energy Majorana modes localized at the two ends of the nanowire [5][7][8]. These zero-energy states combine equal proportions of electrons and holes and are created by second quantized operators satisfying the “Majorana condition” γ† = γ. The

• the crystal structure [27]. The finite cross section of the wires used in the experiments may generate additional phenomena, which are not captured by ideal 1D models. In particular, the orbital effects of the magnetic field, which is oriented parallel to the nanowire, may reduce or even destroy the

Absence of free carriers in silicon nanocrystals grown from phosphorus- and boron-doped silicon-rich oxide and oxynitride

• Daniel Hiller,
• Julian López-Vidrier,
• Keita Nomoto,
• Michael Wahl,
• Wolfgang Bock,
• Tomáš Chlouba,
• František Trojánek,
• Sebastian Gutsch,
• Margit Zacharias,
• Dirk König,
• Petr Malý and
• Michael Kopnarski

Beilstein J. Nanotechnol. 2018, 9, 1501–1511, doi:10.3762/bjnano.9.141

• the bottom end of the nanoscale requires different doping approaches that either relocate the dopants in the surrounding matrix (e.g., Si modulation doping by SiO2:Al) [59] or do not require impurities at all (e.g., electrically reconfigurable nanowire-FETs [60] or p/n-behaviour induced by energy

Cr(VI) remediation from aqueous environment through modified-TiO₂-mediated photocatalytic reduction

• Rashmi Acharya,
• Brundabana Naik and
• Kulamani Parida

Beilstein J. Nanotechnol. 2018, 9, 1448–1470, doi:10.3762/bjnano.9.137

Interplay between pairing and correlations in spin-polarized bound states

• Szczepan Głodzik,
• Aksel Kobiałka,
• Anna Gorczyca-Goraj,
• Andrzej Ptok,
• Grzegorz Górski,
• Maciej M. Maśka and
• Tadeusz Domański

Beilstein J. Nanotechnol. 2018, 9, 1370–1380, doi:10.3762/bjnano.9.129

• square lattice of a superconducting host, (ii) a nanoscopic chain of magnetic impurities on the classical superconductor (i.e., proximitized Rashba nanowire) in its topologically trivial/nontrivial superconducting phase, and (iii) a strongly correlated quantum dot side-attached to the Rashba chain, where

• μN↑ − μN↓. Individual atoms of the nanochain are coupled with such STM tip through For simplicity, we assume constant couplings The low-energy physics of such proximitized Rashba nanowire can be described by [44] where annihilates (creates) an electron of spin σ at site i with energy εi, and tij

• proposals for such nanodevices have been recently discussed by several authors [52][53]. In summary of this section, we emphasize that the Majorana modes coalescing from the YSR states in the proximitized Rashba nanowire are characterized by their magnetic polarization. Indeed, such a feature has been