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

• (n = 2.1) enables photonic confinement in the NW cavities. The observed waveguide nature arises from defect-controlled luminescence in the visible light range of SnO2 and detailed discussion is provided in the photoluminescence study section. For understanding the propagation of luminescence through

Transport signatures of an Andreev molecule in a quantum dot–superconductor–quantum dot setup

• Zoltán Scherübl,
• András Pályi and
• Szabolcs Csonka

Beilstein J. Nanotechnol. 2019, 10, 363–378, doi:10.3762/bjnano.10.36

• , nanodevices provide the confinement of electrons into 1D or 0D. The interplay of these properties is a key ingredient of novel promising qubit realizations, such as Majorana qubits [1][2] and Andreev qubits [3]. The basic physical mechanism behind these applications is the Andreev reflection, when a Cooper

Removal of toxic heavy metals from river water samples using a porous silica surface modified with a new β-ketoenolic host

• Said Tighadouini,
• Smaail Radi,
• Abderrahman Elidrissi,
• Khadija Haboubi,
• Maryse Bacquet,
• Stéphanie Degoutin,
• Mustapha Zaghrioui and
• Yann Garcia

Beilstein J. Nanotechnol. 2019, 10, 262–273, doi:10.3762/bjnano.10.25

• affinity and adsorption capacity for toxic heavy metal detection with less equilibrium time, a discovery that has significant environmental issues. Parameters that may improve the retention effectiveness of the metal ions have also been studied. The system was used for the confinement of lead, cadmium

Magnetic-field sensor with self-reference characteristic based on a magnetic fluid and independent plasmonic dual resonances

• Kun Ren,
• Xiaobin Ren,
• Yumeng He and
• Qun Han

Beilstein J. Nanotechnol. 2019, 10, 247–255, doi:10.3762/bjnano.10.23

• fabrication and compactness. In recent years, compact optical devices based on surface plasmon polaritons (SPPs) have been reported. SPPs propagate along the dielectric–metal interface with the amplitudes decaying exponentially into both sides [16]. The deep subwavelength confinement of SPPs leads to the

Surface plasmon resonance enhancement of photoluminescence intensity and bioimaging application of gold nanorod@CdSe/ZnS quantum dots

• Siyi Hu,
• Yu Ren,
• Yue Wang,
• Jinhua Li,
• Junle Qu,
• Liwei Liu,
• Hanbin Ma and
• Yuguo Tang

Beilstein J. Nanotechnol. 2019, 10, 22–31, doi:10.3762/bjnano.10.3

• and they show excellent quantum confinement for charge carrier and lattice mismatch. In such cases, the energy range of the QDs depends on the relative conduction and valence band offsets for the two materials, and this characteristic can enable many chemical materials or biomolecules to conjugate

• suggests that when metal or chemical materials are doped with QDs, the number of surface trap states (which can lead to exponential PL decay) is affected by the surface passivation and by the degree of quantum confinement. In CdSe/ZnS QDs with higher defect densities, binding with GNRs having very

Zn/F-doped tin oxide nanoparticles synthesized by laser pyrolysis: structural and optical properties

• Florian Dumitrache,
• Iuliana P. Morjan,
• Elena Dutu,
• Ion Morjan,
• Claudiu Teodor Fleaca,
• Monica Scarisoreanu,
• Alina Ilie,
• Marius Dumitru,
• Cristian Mihailescu,
• Adriana Smarandache and
• Gabriel Prodan

Beilstein J. Nanotechnol. 2019, 10, 9–21, doi:10.3762/bjnano.10.2

• SnO2 in its undoped form is an n-type semiconductor with a direct bandgap of 3.6 eV at room temperature. Its n-type conductivity is due to oxygen vacancies in its rutile structure. The bandgap, starting from the bulk value, increases as the size of the nanocrystal decreases, due to electron confinement

Apparent tunneling barrier height and local work function of atomic arrays

• Neda Noei,
• Alexander Weismann and
• Richard Berndt

Beilstein J. Nanotechnol. 2018, 9, 3048–3052, doi:10.3762/bjnano.9.283

• effectively raises the energy required to overcome the potential barrier between the tip and the sample. In the context of the scanning tunneling microscope, the idea of an increased barrier due to lateral confinement has been attributed to J. Tersoff in [27]. Lateral confinement plays a key role in ballistic

• is of the order of 1 eV. This complicates the relation between the local sample work function Φ and the measured Φapp. The shape of the tip also influences the degree of confinement and presumably contributes to the scatter of Φapp observed with different tips. STM images of a Cu(111) surface with

Site-controlled formation of single Si nanocrystals in a buried SiO₂ matrix using ion beam mixing

• Xiaomo Xu,
• Thomas Prüfer,
• Daniel Wolf,
• Hans-Jürgen Engelmann,
• Lothar Bischoff,
• René Hübner,
• Karl-Heinz Heinig,
• Wolfhard Möller,
• Stefan Facsko,
• Johannes von Borany and
• Gregor Hlawacek

Beilstein J. Nanotechnol. 2018, 9, 2883–2892, doi:10.3762/bjnano.9.267

• exception of optical applications. The latter is due to its indirect band gap in the bulk state. Benefiting from their reduced size, Si NCs show optical activity [1][2] and quantum confinement behavior [3] and have inspired novel applications in microelectronics [4], optics [1] and photovoltaics [5][6]. In

• fluence of 172 Si+ nm−2 at 60 keV, the O/Si atomic ratio in the center of the oxide has decreased below 1.5. After simulated annealing, a Si NC band forms close to the interface. Due to the geometric confinement only one layer of silicon NCs forms in the center of the buried oxide layer. Here, a lower

Low cost tips for tip-enhanced Raman spectroscopy fabricated by two-step electrochemical etching of 125 µm diameter gold wires

• Antonino Foti,
• Francesco Barreca,
• Enza Fazio,
• Cristiano D’Andrea,
• Paolo Matteini,
• Onofrio Maria Maragò and
• Pietro Giuseppe Gucciardi

Beilstein J. Nanotechnol. 2018, 9, 2718–2729, doi:10.3762/bjnano.9.254

• tip is the key element in TERS. Its field enhancement and confinement capabilities determine the signal amplification, the spatial resolution and the reproducibility of the results. The material, morphology, aspect ratio and size of the tip apex are expected to determine the optical properties of the

• supported by TERS mapping of a 150 × 150 nm2 area (30 × 30 points) with step size of 5 nm (Figure 10a) in a different zone of the sample in which R6G absorbs in a patchy-like fashion. Spectra acquired on adjacent points (Figure 10b) show the capability to map the confinement of R6G molecules in a region

Size-selected Fe₃O₄–Au hybrid nanoparticles for improved magnetism-based theranostics

• Maria V. Efremova,
• Yulia A. Nalench,
• Eirini Myrovali,
• Anastasiia S. Garanina,
• Ivan S. Grebennikov,
• Polina K. Gifer,
• Maxim A. Abakumov,
• Marina Spasova,
• Makis Angelakeris,
• Alexander G. Savchenko,
• Michael Farle,
• Natalia L. Klyachko,
• Alexander G. Majouga and
• Ulf Wiedwald

Beilstein J. Nanotechnol. 2018, 9, 2684–2699, doi:10.3762/bjnano.9.251

• (modeled r2 = 255 mM−1·s−1) in MAR. The confinement of the NPs in an agarose matrix hinders or at least slows down the diffusion of water molecules near NPs and therefore decreasing r2 values are obtained. Although the theoretical limit [66] for MNP-25 and MNP-44 in SDR of ≈1000 mM−1·s−1 (given their high

Two-dimensional semiconductors pave the way towards dopant-based quantum computing

• José Carlos Abadillo-Uriel,
• Belita Koiller and
• María José Calderón

Beilstein J. Nanotechnol. 2018, 9, 2668–2673, doi:10.3762/bjnano.9.249

• qubits. We distinguish 2D materials that support shallow states with binding energies and Bohr radii comparable to P in Si, and those that support stronger confinement. Each group of materials could serve different purposes with shallower states more suitable for manipulation and deeper ones for storage

Block copolymers for designing nanostructured porous coatings

• Roberto Nisticò

Beilstein J. Nanotechnol. 2018, 9, 2332–2344, doi:10.3762/bjnano.9.218

• weights to obtain a high molecular weight PS homopolymer with “hard confinement”, whereas the low molecular weight one led to “soft confinement”. Thus the thermodynamic stability of the PEO domains can be modulated in a controlled fashion. In a previous study [64], solutions containing PS-b-PEO block

Performance analysis of rigorous coupled-wave analysis and its integration in a coupled modeling approach for optical simulation of complete heterojunction silicon solar cells

• Ziga Lokar,
• Benjamin Lipovsek,
• Marko Topic and
• Janez Krc

Beilstein J. Nanotechnol. 2018, 9, 2315–2329, doi:10.3762/bjnano.9.216

• wavelength-dependent R for different numbers of sublayers and modes used in simulations, we introduce another quantitative measure that highlights the deviations of the different simulations. As the JSC of the solar cell is the most important quantity related to optical confinement in solar cells, we

Metal–dielectric hybrid nanoantennas for efficient frequency conversion at the anapole mode

• Valerio F. Gili,
• Lavinia Ghirardini,
• Davide Rocco,
• Giuseppe Marino,
• Ivan Favero,
• Iännis Roland,
• Giovanni Pellegrini,
• Lamberto Duò,
• Marco Finazzi,
• Luca Carletti,
• Andrea Locatelli,
• Aristide Lemaître,
• Dragomir Neshev,
• Costantino De Angelis,
• Giuseppe Leo and
• Michele Celebrano

Beilstein J. Nanotechnol. 2018, 9, 2306–2314, doi:10.3762/bjnano.9.215

• -field enhancement, which are characteristic of this mode. Plasmonic nanostructures, on the other hand, remain the most promising solution to achieve strong local field confinement, especially in the NIR, where metals such as gold display relatively low losses. Results: We present a nonlinear hybrid

• antenna based on an AlGaAs nanopillar surrounded by a gold ring, which merges in a single platform the strong field confinement typically produced by plasmonic antennas with the high nonlinearity and low loss characteristics of dielectric nanoantennas. This platform allows enhancing the coupling of light

• enhancement is only the result of the better field confinement inside the dielectric material brought about by the hybrid configuration, as shown in Figure 3d. A log–log plot of the emission as a function of the power acquired from a type-2 platform using a narrowband filter at 775 nm (25 nm bandwidth) shows

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

• doping to fail for Si nano-crystals (NCs) showing quantum confinement. To introduce electron- (n-) or hole- (p-) type conductivity, usn-Si may not require doping, but an energy shift of electronic states with respect to the vacuum energy between different regions of usn-Si. We show in theory and

• Si3N4 is 0.81 eV which clearly confirms our h-DFT calculations. For the 2.6 nm NWell embedded in Si3N4 we obtain a Eion of 0.06 eV below the value of bulk Si (Figure 5b). The ICT may thus overcompensate quantum confinement and induce a negative ΔEion to bulk Si. The ICT impact length on Si-NWells can be

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

• vector distributions are almost independent from the phase and that these variations can be neglected (more details are given in Supporting Information File 1). The SiNx waveguide shows efficient vertical and horizontal confinement of the propagating light. By comparing Figure 2b and Figure 4c, a

• significant improvement at the LED–waveguide coupling was achieved by removing the spin-on-glass SiOx layer. As shown in Figure 4b, the leakage caused by the multimode nature at the waveguide–detector coupling is mostly reduced thanks to the lateral confinement of the waveguide with a reduced width. The final

• efficiency detected by the NW photodetector and calculated using the 3D model is 65.5%, which is even better than the 2D simulation result due to better confinement in the 3D structure. Conclusion By using FDTD simulations, the efficiency of light coupling in a NW LED–waveguide–NW photodetector integrated

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

• electromagnetic field enhancement and confinement. This ratio, taken as a measure of the performance of an antenna, can even exceed that exhibited by trimer AuNP antennas composed of comparable building blocks with larger gap sizes. Fluctuations in the far-field and near-field properties are observed, which are

• likely caused by distinct deviations of the gap geometry arising from the faceted structure of the applied colloidal AuNPs. Keywords: atomistic plasmonics; dumbbell dimer antennas; electromagnetic field enhancement; light confinement; nanolens; nanoscale morphology; Introduction The introduction of the

• applications, is the ability of optical antennas to provide a high signal enhancement ratio and light confinement across the UV–vis–NIR spectral range. The development of new configurations has always come along with the question of fundamental limitations in regard to the obtainable electromagnetic field

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

• some critical Zeeman field without the expected oscillatory pattern [12][19][24][25]. Several mechanisms have been proposed to account for the reduction or lack of oscillations, such as smooth confinement [21][26][27][28], strong spin–orbit coupling [29], position-dependent pairing [30], orbital

• unexplored before is the creation of deep potential wells at the ends of the wire close to the bulk metallic electrodes. These wells, obtained explicitly here through the self-consistent calculation, are similar to the confinement potentials typical of quantum dots. Localized quantum dot-like energy levels

Light–Matter interactions on the nanoscale

• Mohsen Rahmani and
• Chennupati Jagadish

Beilstein J. Nanotechnol. 2018, 9, 2125–2127, doi:10.3762/bjnano.9.201

• graphene with electromagnetic radiation is fascinating due to the two-dimensional confinement of electrons and the exceptional band structure of graphene. Graphene has a simple band structure with zero band gap, but its optical response is nontrivial. Subsequently, other two-dimensional (2D) materials

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

• ][112][113] induced by the interplay of the surface-induced confinement and the structural correlations of charged and hydrophobic molecular sections, has potential implications for the nanoscale lubrication properties of the resulting interfaces. These properties can be affected not only by the

• probing what each mobile particle in the sliding layer is doing instant after instant at the interface. In short, charged polystyrene spheres in aqueous solution repel each other, forming, under confinement, a 2D hexagonal crystal [158][159][160][161][162][163]. This crystal is driven across an either

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

• wavelength of 800 nm. At the operating voltage, the emission of the electron-fed antenna is typically spanning the visible and near-infrared spectral region. For the TiO2 geometries discussed here, the confinement loss is calculated to be about 10−2 dB for a 10 μm long waveguide. We may therefore neglect

• engineering a cladding material surrounding the active emitting area [65], by a heterogeneous integration of the source in a structured waveguide [66][67], or by using extreme modal confinement [68]. We have tried simple steps to increase the apparent coupling yield to the modes sustained by the geometries

• confinement while maintaining micrometer-range propagation [69]. Excitation of the mode from free-space radiation is usually insured by the mediation of passive antenna couplers [70]. In the example shown in Figure 7, the 130 nm wide slot is directly excited in situ by the emission of the electron-fed antenna

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

• limitations should be considered in view of the implementation of a DHE methodology on ultrashallow layers. One is quantum confinement, which has been shown to induce band modifications in ultrathin SOI layers with thicknesses close to ca. 3 nm [36]. However, the SOI and SiGeOI layers to be investigated in

• this work will have a minimum thickness of about 6 nm, so that the quantum-confinement effect can be neglected. An additional low-dimension effect is the dielectric confinement, which has been investigated in silicon nanowires surrounded by a dielectric material (such as its native oxide) [37][38]. For

• ] indicated a perfect correlation between measured activation and simulated activation, suggesting that dielectric confinement affects more significantly 3D than 2D structures at low dimensions. Finally, when quantifying the active dopant and mobility depth profiles with DHE, the surface-depletion effect

The role of the Ge mole fraction in improving the performance of a nanoscale junctionless tunneling FET: concept and scaling capability

• Hichem Ferhati,
• Fayçal Djeffal and
• Toufik Bentrcia

Beilstein J. Nanotechnol. 2018, 9, 1856–1862, doi:10.3762/bjnano.9.177

• Figure 1, L is the channel length, tch refers to the channel thickness, Nd is the doping concentration of the channel, and Ls and Ld denote the extension lengths of source and drain, respectively. The accurate modeling of the nanoscale DG-HJ-JL TFET requires taking into account quantum-confinement

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

• to the (002) and (004) planes of 2H-MoS2 [18]. However, a slightly higher interplanar distance of 0.63 nm near the edges (in agreement with plane-view TEM) was also observed. It indicates that the NSs possess a slightly different lattice parameter due to the crystal confinement at the top end

Nitrogen-doped carbon nanotubes coated with zinc oxide nanoparticles as sulfur encapsulator for high-performance lithium/sulfur batteries

• Yan Zhao,
• Zhengjun Liu,
• Liancheng Sun,
• Yongguang Zhang,
• Yuting Feng,
• Xin Wang,
• Indira Kurmanbayeva and
• Zhumabay Bakenov

Beilstein J. Nanotechnol. 2018, 9, 1677–1685, doi:10.3762/bjnano.9.159

• precise control of its morphology, these carbon materials can also play an active role in S confinement [4]. For example, it has been reported that the functional nitrogen groups in N-doped graphene (NG) sheets have a good binding capability for lithium polysulfides, which can greatly enhance the life of

• to 822 mAh·g−1. This indicates that the as-prepared S/ZnO@NCNT composite is very stable and can tolerate the abusive condition of high-rate Li ion insertion and deletion. In addition to a strong S “confinement” effect of the active ZnO surface, this might also be attributed to the NCNT network and