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

• end of the waveguide, a horizontal NW detector is positioned, with its 1.5 µm long end overlapped with the waveguide, and it is also embedded into a spin-on-glass layer. The axes of the LED and detector NWs are aligned with the waveguide direction as shown in Figure 1a. The optical refractive indices

Dumbbell gold nanoparticle dimer antennas with advanced optical properties

• Janning F. Herrmann and
• Christiane Höppener

Beilstein J. Nanotechnol. 2018, 9, 2188–2197, doi:10.3762/bjnano.9.205

• determined to ≈22 whilst the CB[8]-mediated dimers enhance the fluorescence signal of a single z-aligned dye molecule on average by a factor ≈48. Apparently the reproducibility for the CB[8]-mediated dimers is lower than for the thiol-mediated dimers, although a high rigidity is expected for the CB[8]. The

• the AuNPs leads to multiple possible gap configurations. Large planar gaps are formed in the case that the two AuNPs assemble in a fashion that the gap-forming facets are aligned parallel to each other (Figure 6A). However, the gap formation can include also facet edges (Figure 6B) or the corner of

• sample through the laser focus using a piezoelectric scanner (Nano-H, Mad City Labs, USA). For each image pixel the emitted fluorescence signal is integrated for 5–10 ms. For the antenna-enhanced fluorescence emission, the antenna is precisely aligned in the laser focus and the antenna–sample distance is

Electrospun one-dimensional nanostructures: a new horizon for gas sensing materials

• Muhammad Imran,
• Nunzio Motta and
• Mahnaz Shafiei

Beilstein J. Nanotechnol. 2018, 9, 2128–2170, doi:10.3762/bjnano.9.202

Spin-coated planar Sb₂S₃ hybrid solar cells approaching 5% efficiency

• Pascal Kaienburg,
• Benjamin Klingebiel and
• Thomas Kirchartz

Beilstein J. Nanotechnol. 2018, 9, 2114–2124, doi:10.3762/bjnano.9.200

• measurements [67]. The HOMO of KP115 is thus better aligned with the valence band of Sb2S3 which could be beneficial for the Voc and FF. Indeed, for the Sb-TU process both values are significantly larger for the better-matching KP115. However, this is not the case for the Sb-BDC process where the Sb2S3/KP115

A scanning probe microscopy study of nanostructured TiO₂/poly(3-hexylthiophene) hybrid heterojunctions for photovoltaic applications

• Laurie Letertre,
• Roland Roche,
• Olivier Douhéret,
• Hailu G. Kassa,
• Denis Mariolle,
• Nicolas Chevalier,
• Łukasz Borowik,
• Philippe Dumas,
• Benjamin Grévin,
• Roberto Lazzaroni and
• Philippe Leclère

Beilstein J. Nanotechnol. 2018, 9, 2087–2096, doi:10.3762/bjnano.9.197

• vertically aligned nanostructuration of TiO2 also makes this system attractive, since it ensures direct percolation paths for the photogenerated electrons from the donor–acceptor interface to the cathode, while providing a simple, controlled and ordered architecture. Furthermore, studies are available in

Metal-free catalysis based on nitrogen-doped carbon nanomaterials: a photoelectron spectroscopy point of view

• Mattia Scardamaglia and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2018, 9, 2015–2031, doi:10.3762/bjnano.9.191

• in 2009 by Gong and co-workers [19]; it was based on nitrogen-doped vertically aligned carbon nanotubes (N-vCNTs). Using a rotating ring-disk electrode (RRDE) when measuring steady-state voltammograms in alkaline solution, the authors showed that the ORR activity of N-vCTNs was superior to undoped

• vCNTs, to randomly oriented N-CNTs, and, in particular, to commercially available platinum-loaded carbon (Vulcan XC-72R), as reported in Figure 1. The electrochemical mechanism for the ORR was the same for aligned and disordered CNTs. The improved electrocatalytic performance of vCNTs was associated

• with a better-defined surface area of the aligned tips at the interface with the electrolyte solution, which facilitates the electrolyte/reactant diffusion. A strong enhancement of the currents was observed when comparing N-CNTs to undoped nanotubes. Furthermore, they demonstrated that the glassy N

Recent highlights in nanoscale and mesoscale friction

• Andrea Vanossi,
• Dirk Dietzel,
• Andre Schirmeisen,
• Ernst Meyer,
• Rémy Pawlak,
• Thilo Glatzel,
• Marcin Kisiel,
• Shigeki Kawai and
• Nicola Manini

Beilstein J. Nanotechnol. 2018, 9, 1995–2014, doi:10.3762/bjnano.9.190

• [170]. Indeed, the competition between the superlubric orientationally twisted phase and the pinned phase consisting of an array of aligned islands leads to a first-order transition [171]. Experiments confirm this theory, showing the first-order transition with a coexistence region as a function of the

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

• vertically aligned ZnO nanowires [18][19][20][21][22][23][24][25][26][27]. The principle of nanogenerators is that the piezoelectric potential produced by the piezoelectric effect can produce a current in an external circuit when the ZNW is deformed. Specifically, a transversely applied force makes the

Synthesis of carbon nanowalls from a single-source metal-organic precursor

• André Giese,
• Sebastian Schipporeit,
• Volker Buck and
• Nicolas Wöhrl

Beilstein J. Nanotechnol. 2018, 9, 1895–1905, doi:10.3762/bjnano.9.181

• acetylacetonate; carbon nanowalls; growth zones; ICP PECVD; metal-organic precursor; Introduction The first report of the synthesis of carbon nanowalls (CNWs), i.e., wall-like carbon nanosheets aligned perpendicular to the substrate, was given by Wu and co-workers [1]. The average thickness of these sheets was

• measured by using transmission electron microscopy to be of several nanometers [2][3][4][5][6][7], similar to that of vertically aligned carbon nanotube arrays [8]. In CNWs, few graphene layers stick together like thin graphite flakes. The height of the CNWs can be of several micrometers, contributing to

• number of dangling bonds that act as nucleation sites for randomly orientated carbon nanoflakes. 2D growth and the subsequent formation of (few-layer) graphene sheets follow. The nanoflakes being almost vertically aligned on the substrate grow fastest to finally form vertically standing nanosheets. The

SO₂ gas adsorption on carbon nanomaterials: a comparative study

• Deepu J. Babu,
• Divya Puthusseri,
• Frank G. Kühl,
• Sherif Okeil,
• Michael Bruns,
• Manfred Hampe and
• Jörg J. Schneider

Beilstein J. Nanotechnol. 2018, 9, 1782–1792, doi:10.3762/bjnano.9.169

• -walled carbon nanotubes (SWNTs) and vertically aligned carbon nanotubes (VACNTs) are investigated and compared against the adsorption characteristics of activated carbon and graphene oxide (GO). A comprehensive overview of the adsorption behavior of this family of carbon adsorbents is given for the first

• found to dominate the adsorption behavior in activated carbon, SO2 adsorption on carbon nanomaterials occurs by a physisorption mechanism. Keywords: adsorption; carbon nanohorns; carbon nanotubes; heat of adsorption; sulfur dioxide; vertically aligned carbon nanotubes; Introduction Compared to the

• aligned CNTs (VACNTs). Compared to randomly oriented CNTs, VACNTs preserve the characteristic bundled morphology over macro-sized dimensions leading to a well-defined structure as shown in Figure 1d. Gases can adsorb on the interior of the CNTs known as the endohedral sites, on interstitial sites formed

Preparation of micro/nanopatterned gelatins crosslinked with genipin for biocompatible dental implants

• Reika Makita,
• Tsukasa Akasaka,
• Seiichi Tamagawa,
• Yasuhiro Yoshida,
• Saori Miyata,
• Hirofumi Miyaji and
• Tsutomu Sugaya

Beilstein J. Nanotechnol. 2018, 9, 1735–1754, doi:10.3762/bjnano.9.165

• the cells on groves were aligned along the direction of the grooves. In contrast, the cells on pillars and holes exhibited randomly elongated filopodia. The vinculin spots of the cells were observed on the top of ridges and pillars or the upper surface of holes. The results of a cell attachment assay

• . Unfortunately, auto-fluorescence, caused by azo-compounds in the crosslinked genipin, slightly interfered with the observation of green and red fluorescence of the cells [50]. The red fluorescence of actin was particular not clear in this observation. The cells and nuclei on the grooves were aligned along the

• direction of the grooves (Figure 6a–c). The vinculin in the cells on the grooves was observed on the top of the ridge and was aligned along the direction and size of the ridge. The orientation of the cells and nuclei on the grooves with widths of 500 nm and heights of 500 nm was weaker than that of the

Toward the use of CVD-grown MoS₂ nanosheets as field-emission source

• Geetanjali Deokar,
• Nitul S. Rajput,
• Junjie Li,
• Francis Leonard Deepak,
• Wei Ou-Yang,
• Nicolas Reckinger,
• Carla Bittencourt,
• Jean-Francois Colomer and
• Mustapha Jouiad

Beilstein J. Nanotechnol. 2018, 9, 1686–1694, doi:10.3762/bjnano.9.160

• ), CIRMAP, Research Institute for Materials Science and Engineering, University of Mons, Mons, Belgium 10.3762/bjnano.9.160 Abstract Densely populated edge-terminated vertically aligned two-dimensional MoS2 nanosheets (NSs) with thicknesses ranging from 5 to 20 nm were directly synthesized on Mo films

• transferred NSs sample showed excellent field-emission properties. A low turn-on field of 3.1 V/μm at a current density of 10 µA/cm2 was measured. The low turn-on field is attributed to the morphology of the NSs exhibiting vertically aligned sheets of MoS2 with sharp and exposed edges. Our findings show that

• displays, X-ray sources and cold-cathode electron sources [2]. 1D and 2D materials such as carbon nanotubes [3], ZnO nanorods [1], LaB6 nanowires [2], SnS2 nanosheets (NSs) [4], vertically aligned graphene [5], WS2 nanotubes [6], MoSe2 nanosheets [7], and MoS2 NSs [8][9][10] are potential field-emitter

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

• precisely aligned. (ii) Even for a simple S–TS junction, a finite Josephson current is expected when the TS wire is modeled as spinful nanowire. This effect is due to the residual s-wave pairing character of the spinful TS model [2][3]. Interestingly, upon changing a control parameter, e.g., the bulk Zeeman

• ] then rule out a supercurrent for TS wires in the deep topological regime. We show below that unless B is inadvertently aligned with the MBS spin polarization axis, spin mixing will indeed generate a supercurrent. The S/TS leads are coupled to the QD via a tunneling Hamiltonian [70], where ψσ and ψ are

• to have a finite By-component with defining the MBS spin polarization direction. In particular, if B is aligned with , the supercurrent in Equation 23 vanishes identically since s-wave Cooper pairs cannot tunnel from the S lead into the TS wire in the absence of spin flips [31]. Otherwise, the CPR

Photoluminescence of CdSe/ZnS quantum dots in nematic liquid crystals in electric fields

• Margarita A. Kurochkina,
• Elena A. Konshina and
• Daria Khmelevskaia

Beilstein J. Nanotechnol. 2018, 9, 1544–1549, doi:10.3762/bjnano.9.145

• the director field under the action of an electric field. We have used a nematic liquid crystal with positive dielectric anisotropy as the LC matrix. The liquid crystal doped with QDs was aligned in parallel (a vertical orientation) or perpendicular (a planar orientation) to the electric field vector

Excitation of nonradiating magnetic anapole states with azimuthally polarized vector beams

• Aristeidis G. Lamprianidis and
• Andrey E. Miroshnichenko

Beilstein J. Nanotechnol. 2018, 9, 1478–1490, doi:10.3762/bjnano.9.139

• states. The disks are aligned along the optical axis. The particular design of the excitation is essential in obtaining nonradiating behavior of the cylinders. Again, we want to emphasize that the symmetries of the cylinder are of crucial importance. Such a particle is rotationally symmetric, which means

Robust midgap states in band-inverted junctions under electric and magnetic fields

• Álvaro Díaz-Fernández,
• Natalia del Valle and
• Francisco Domínguez-Adame

Beilstein J. Nanotechnol. 2018, 9, 1405–1413, doi:10.3762/bjnano.9.133

• topological crystalline insulators due to the band inversion at the L points of the Brillouin zone as the Sn fraction increases [8][26][27]. In order to keep the algebra as simple as possible, we restrict ourselves to the symmetric heterojunction with same-sized and aligned gaps, as depicted in Figure 1a

• “” in a vector indicates the nullification of its z-component. In the case of aligned and same-sized gaps, it is found that , with and the interface dispersion relation is a single Dirac cone , where the origin of energy is taken at the center of the gaps [20]. v is the group velocity at the Fermi

• spinful two-band model that is equivalent to the Dirac model for relativistic electrons. The mass term is half the bandgap and changes its sign across the junction. For the sake of algebraic simplicity, we assumed same-sized and aligned gaps, although this is not a serious limitation to the validity of

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

• aligned perpendicularly to the wire and the magnetic field parallel to it, leading to the effective intersite pairing of identical spins and (under specific conditions) inducing zero-energy end modes resembling Majorana quasiparticles. This issue has been recently studied very intensively but here we

• type (hole or particle) of the YSR states at a given distance r. The left and right panels correspond to λ = 0 and λ = t, respectively. The effective quasiparticle spectrum ρiσ(ω) as a function of a magnetic field B aligned along the nanochain obtained for σ = ↑ (upper panel) and σ = ↓ (bottom panel

Induced smectic phase in binary mixtures of twist-bend nematogens

• Anamarija Knežević,
• Irena Dokli,
• Marin Sapunar,
• Suzana Šegota,
• Ute Baumeister and
• Andreja Lesac

Beilstein J. Nanotechnol. 2018, 9, 1297–1307, doi:10.3762/bjnano.9.122

• were sampled every 0.2 ps from the dynamics. The sampled geometries are shown in Figure 9a. The snapshots are aligned to maximize the overlap of the benzene ring of each geometry. In this way, the motion of the alkyl chain during the dynamics can be seen clearly. Both the all-trans conformer and

• texture after shearing the sample at 82 °C, d) 2D XRD patterns for a sample of 73 mol % BB mixture aligned in the magnetic field obtained on cooling from the isotropic liquid at 73 °C. IR spectra of pure BB (red), pure CBI (green) and a 73 mol % BB mixture (blue) at room temperature. IR spectra in the CH2

• molecular dynamics. Snapshots were taken every 0.2 ps from a 10 ps molecular dynamics simulation at 80 K. To illustrate the motion of the alkyl chain separately from the motion of the remainder of the molecule, the snapshots are shown with the benzene ring of each geometry aligned, and only the alkyl chain

Formation and development of nanometer-sized cybotactic clusters in bent-core nematic liquid crystalline compounds

• Yuri P. Panarin,
• Sithara P. Sreenilayam,
• Jagdish K. Vij,
• Anne Lehmann and
• Carsten Tschierske

Beilstein J. Nanotechnol. 2018, 9, 1288–1296, doi:10.3762/bjnano.9.121

• molecules were aligned by surface treatment and one of the short axes was also aligned by the electric field. In more recent studies, the biaxiality of the sample studied was confirmed [3][4][5] by electro-optical switching [23], polarizing infrared spectroscopy (PIR) [24], polarizing optical microscopy

• (POM) [25], Raman scattering [26][27], XRD [28][29], photon correlation spectroscopy (PCS) [27][30][31] and NMR [32][33]. Recently Kim et al. [29] carried out X-ray experiments on a bent-core system in its nematic phase. They aligned the long molecular axes by applying a strong magnetic field parallel

• resistance of the ITO. The capacitance of the empty cell was measured. These measurements on the aligned liquid crystalline sample were carried out under cooling from 110 to 60 °C. The temperature was varied in steps of 0.5 °C under the application of a weak voltage of 0.1 V. The temperature of the cell with

Surface characterization of nanoparticles using near-field light scattering

• Eunsoo Yoo,
• Yizhong Liu,
• Chukwuazam A. Nwasike,
• Sebastian R. Freeman,
• Brian C. DiPaolo,
• Bernardo Cordovez and
• Amber L. Doiron

Beilstein J. Nanotechnol. 2018, 9, 1228–1238, doi:10.3762/bjnano.9.114

• output edge where transmitted light is collected by a photodetector. Three polarization-maintaining optical fibers are supported by a silicon v-groove array and are optically aligned to the three waveguides permanently bonded to the chips. Each chip has two through-holes for fluidic access. Fluid lines

Circular dichroism of chiral Majorana states

• Javier Osca and
• Llorenç Serra

Beilstein J. Nanotechnol. 2018, 9, 1194–1199, doi:10.3762/bjnano.9.110

• chiral band. On the contrary, states that are not aligned along the chiral band in Figure 2a,b are bulk states separated by a gap from zero energy. Absorption and CD Absorption cross-sections and CD for the spectra of the rectangle with different pairing energies in the two layers (Figure 1d) are shown

A simple extension of the commonly used fitting equation for oscillatory structural forces in case of silica nanoparticle suspensions

• Sebastian Schön and
• Regine von Klitzing

Beilstein J. Nanotechnol. 2018, 9, 1095–1107, doi:10.3762/bjnano.9.101

• movement of the z-piezo in nanometers. The data were analyzed as follows: 1) Force and separation were calculated using the sensitivity slope of the linear contact region and the spring constant of the cantilever, which is determined from the thermal spectrum. 2) All force curves were aligned in relation

• to the y-axis using a linear fit of the force data at large separation, individually for each curve. 3) All force curves were aligned in relation to the x-axis using the contact region of the force curve that has already been used to determine the sensitivity. 4) All 100 force curves were combined

Review on nanoparticles and nanostructured materials: history, sources, toxicity and regulations

• Jaison Jeevanandam,
• Ahmed Barhoum,
• Yen S. Chan,
• Alain Dufresne and
• Michael K. Danquah

Beilstein J. Nanotechnol. 2018, 9, 1050–1074, doi:10.3762/bjnano.9.98

• structures in their feet that are aligned in a series of a small ridges with a projection of 200 nm width in each hair. This increases the total surface area of gecko feet and leads to a van der Waals interaction mediated strong surface adhesion [241]. Similarly, the crystalline composite of CaCO3 crystals

• and protein that are aligned in a column and layers of calcite, forms the thin and strong eggshell. During the eggshell formation, the CaCO3 NPs begin as an amorphous mineral which is transformed by the c-type lectin proteins into ordered crystals. The crystal transformation is initiated by the

Magnetic characterization of cobalt nanowires and square nanorings fabricated by focused electron beam induced deposition

• Federico Venturi,
• Gian Carlo Gazzadi,
• Amir H. Tavabi,
• Alberto Rota,
• Rafal E. Dunin-Borkowski and
• Stefano Frabboni

Beilstein J. Nanotechnol. 2018, 9, 1040–1049, doi:10.3762/bjnano.9.97

• performed using the software Holoworks [29]. The reconstructed phase images were aligned with each other digitally and half of the difference between them was evaluated to subtract the mean inner potential contribution to the phase, in order to obtain the magnetic contribution to the phase alone [30], both

• monodomain states, with their magnetization aligned along their long axes due to shape anisotropy [13]. Impurities are present on some samples (especially for the 20 s and 40 s depositions at 5 keV), resulting in flux-closure domain states, which deform the dipole-like phase structure locally. These

• , at the bottom left, which is aligned in the opposite way, in response to the direction of the applied magnetic field. In the following, the ability of L-TEM to provide a direct visualization of the switching process of the horseshoe state in a square nanoring is demonstrated. Just as for nanowires

Automated image segmentation-assisted flattening of atomic force microscopy images

• Yuliang Wang,
• Tongda Lu,
• Xiaolai Li and
• Huimin Wang

Beilstein J. Nanotechnol. 2018, 9, 975–985, doi:10.3762/bjnano.9.91

• certain width was first aligned to the starting point of a scan line. As demonstrated in Figure 6d, only the portion of the background points within the window was fitted as a third-order polynomial curve at each time of window sliding. After the polynomial fitting, the value on the polynomial curve at