Impact of the anodization time on the photocatalytic activity of TiO₂ nanotubes

• Jesús A. Díaz-Real,
• Geyla C. Dubed-Bandomo,
• Juan Galindo-de-la-Rosa,
• Luis G. Arriaga,
• Janet Ledesma-García and
• Nicolas Alonso-Vante

Beilstein J. Nanotechnol. 2018, 9, 2628–2643, doi:10.3762/bjnano.9.244

• dielectric constant of the material. From the CV curves, an increase in the capacitive current was observed towards lower potential values, which is typical for a transition to the accumulation region of n-type semiconductors. The calculated values for Eg and ND are summarized in Table 3, and compared to the

Enhancement of X-ray emission from nanocolloidal gold suspensions under double-pulse excitation

• Wei-Hung Hsu,
• Frances Camille P. Masim,
• Armandas Balčytis,
• Hsin-Hui Huang,
• Tetsu Yonezawa,
• Aleksandr A. Kuchmizhak,
• Saulius Juodkazis and
• Koji Hatanaka

Beilstein J. Nanotechnol. 2018, 9, 2609–2617, doi:10.3762/bjnano.9.242

• [26], respectively. Theory: Epsilon-Near-Zero (ENZ)-Material A strong generation of X-rays is related to a large amount of absorbed energy and a high temperature [3][4]. In terms of relative permittivity (dielectric constant), εr, a transparent medium (water) with colloidal gold nanoparticles

• represents an effective medium with an overall positive real part of the permittivity. Upon excitation, the material is approaching dielectric breakdown and a state of εr ≈ 0 (epsilon-near-zero (ENZ) state; ). Under the ENZ condition, the strongest absorption takes place [36][37]: Here, εi is the intrinsic

• be calculated from the consideration that all absorbed energy density is converted to thermal energy of electrons. It can be calculated from the ablation threshold expression of a dielectric [37]: where ls = c/(κω) is the skin depth related to the imaginary part of the refractive index , c is the

Au–Si plasmonic platforms: synthesis, structure and FDTD simulations

• Anna Gapska,
• Marcin Łapiński,
• Paweł Syty,
• Wojciech Sadowski,
• Józef E. Sienkiewicz and
• Barbara Kościelska

Beilstein J. Nanotechnol. 2018, 9, 2599–2608, doi:10.3762/bjnano.9.241

• polarized light waves, then the results were averaged to obtain the non-polarized wave for which all results are presented. While solving the Maxwell equations through FDTD calculations, the complex dielectric function plays a crucial role as it describes dispersion in both metal and dielectric layers in

• the simulated systems. For metals in an oscillating external field, this function depends on the oscillation frequency, and its proper modeling is a very important step in the simulation process. In our case, the dielectric functions of gold [26] and silicon [27] were fitted to the Lorentz model [28

Directional light beams by design from electrically driven elliptical slit antennas

• Shuiyan Cao,
• Eric Le Moal,
• Quanbo Jiang,
• Aurélien Drezet,
• Serge Huant,
• Jean-Paul Hugonin,
• Gérald Dujardin and
• Elizabeth Boer-Duchemin

Beilstein J. Nanotechnol. 2018, 9, 2361–2371, doi:10.3762/bjnano.9.221

• , bull’s-eye, nanoparticle dimer, or wire antennas), coupled in the near field (or incorporating in their design) an electrically driven nanosource of surface plasmon polaritons (SPPs, light waves coupled to electron density oscillations at a metal–dielectric interface). In particular, the electrical SPP

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

• Centre de Nanosciences et de Nanotechnologies, CNRS-UMR9001, Route de Nozay, 91460 Marcoussis, France Nonlinear Physics Centre, Research School of Physics and Engineering, Australian National University, 2601 ACT Canberra, Australia 10.3762/bjnano.9.215 Abstract Background: Dielectric nanoantennas have

• 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

• dielectric materials the electric field penetrates deeply into the volume [16], the exploitation of large bulk nonlinearities also enables enhanced nonlinear light–matter interactions at the nanoscale. Third-harmonic generation (THG) was the first nonlinear effect observed in nanoscale semiconductors with

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

• , Si modulation doping of adjacent dielectric layers based on nitrides [11] and oxides [12], in analogy to modulation doping of III–V semiconductors, were shown to be an alternative to conventional impurity doping. It would be ideal to achieve electron- (n-) or hole- (p-) type conductivity in usn-Si

• ) approach. Following an explanation of the theoretical and experimental methods used, we turn to results for Si-NCs obtained from h-DFT. Here, we focus on the electronic structure of Si-NCs as a function of the embedding dielectric and its thickness of up to 3 monolayers (MLs). The latter dependence

• requires the use of NCs to keep the h-DFT computation effort practicable; NWires with more than 1 ML dielectric embedding are beyond the feasible computation effort at the level of accuracy we use. As an ultimate theoretical test, we present h-DFT results of two Si-NCs, one embedded in SiO2 and the other

Filling nanopipettes with apertures smaller than 50 nm: dynamic microdistillation

• Evelyne Salançon and
• Bernard Tinland

Beilstein J. Nanotechnol. 2018, 9, 2181–2187, doi:10.3762/bjnano.9.204

• . Results and Discussion Quartz capillaries, being of pure silica, have certain intrinsic properties (low dielectric constant, low loss factor, high volume resistivity, strength and chemical purity) that make them appropriate for the reproducible electrical measurements described below. Notably, they

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

• -dimensional model of the dielectric surroundings, here we show that, under certain circumstances, these interactions lead to a suppression of the Majorana oscillations predicted by simpler theoretical models, and to the formation of low-energy quantum-dot states that interact with the Majorana modes. Both

• (SC) layer on one of its faces and to two bulk normal leads at both ends, separated by thin insulating barriers. In Figure 1a we indicate the characteristic dielectric constants of each region, which are relevant for the calculation of the induced potential through Poisson’s equation (discussed below

• or μ proportional to the Majorana charge QM and the strength of the interaction. This was already shown in [33] but for a simplified dielectric profile where the presence of the superconducting shell had been ignored. We here include it and find that the size of the pinned regions decreases but the

Light–Matter interactions on the nanoscale

• Mohsen Rahmani and
• Chennupati Jagadish

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

• in metals), the knowledge is still valuable for developing new strategies for light–matter interactions on the nanoscale. High refractive index dielectric [11] and semiconductor [12] nanostructures have been recently exploited as an alternative to plasmonics [13]. Dielectrics and semiconductors

• in the engineering of light behaviour at the nanoscale. Among various applications of dielectric nanostructures, metasurfaces, composed of a single or a few stacked layers of subwavelength nanostructures/particles, are growing in popularity [14]. This is because metasurfaces can offer a diverse range

• developments in this area. This Thematic Series can guide readers in understanding the physics of light matter–interaction with various kinds of nanostructures, including metallic (plasmonic), dielectric and semiconductor, 2D, as well as hybrid nanostructures [18]. Meanwhile, readers can become more familiar

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

• on current density and often increases light absorption. This increased light absorption comes from optical resonances in nanomaterials, which have been studied extensively in both metallic (plasmonic) and dielectric material systems [9][10][11][12][13]. One hallmark of resonant absorption is the

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

• antennas are devices operating at frequencies from visible light to infrared [8]. They were primarily developed to enhance light–matter near-field interactions [9] via the excitation of surface plasmons for metal-based devices [10] or Mie resonances for dielectric antennas [11][12]. Interestingly, optical

• versatile and low-cost integrated light sources, and optical tunneling gap antennas may provide an alternative technology to solid-state light emitting diodes or quantum dots. Coupling of such a junction have been recently demonstrated in plasmonic strips [27][59] and we extend the concept to dielectric

• show also that light emerges from the distal end of the TiO2 stripes indicating that a portion of the power emitted by the electron-fed antennas is coupled to the dielectric structure and is transmitted away from the radiating feedgap. The optical tunneling gap antenna may therefore be used as an

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

• 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

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

• dielectric constants and eiL being the electromechanical coupling coefficients. K, L = 1, 2,…, 6; i, j = 1, 2, 3; The cross section of a bent ZnO nanowire is assumed to be circular in our analysis, which was also assumed by, for example, Gao and Wang [26][27], Henneghien et al. [34], and Maslov and co

• cross section, and r and θ stand for the radial and the tangential coordinate, respectively, as shown in Figure 1. ε0 is the dielectric coefficient of the vacuum. Results and Discussion We calculate carrier concentration fluctuation, piezoelectric potential, electric fields, boundary charges by using

Synthesis of hafnium nanoparticles and hafnium nanoparticle films by gas condensation and energetic deposition

• Irini Michelakaki,
• Nikos Boukos,
• Dimitrios A. Dragatogiannis,
• Spyros Stathopoulos,
• Costas A. Charitidis and
• Dimitris Tsoukalas

Beilstein J. Nanotechnol. 2018, 9, 1868–1880, doi:10.3762/bjnano.9.179

• cross section in neutron absorption [32]. Hafnium alloys are used in medical applications because they are biocompatible and exhibit high corrosion resistance as well as in aerospace technology because it can increase the mechanical strength of materials [33]. Furthermore, because of its high dielectric

• constant HfO2 and its compounds are used in the field of microelectronics for the manufacturing of integrated circuits and more particularly as gate dielectrics of metal-oxide semiconductor transistors having replaced the traditional thermally grown SiO2 dielectric [34]. More recently, HfO2 was also

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

• describes schematically the investigated DG-HJ-JL TFET structure. The cornerstone of the proposed design is the assumption of a uniformly and highly doped heterochannel (Si1−xGex/Si/Ge), which can be indicated by n+/n+/n+. In addition, the proposed design is suggested with a HfO2 gate dielectric in order to

Nanoscale electrochemical response of lithium-ion cathodes: a combined study using C-AFM and SIMS

• Jonathan Op de Beeck,
• Nouha Labyedh,
• Alfonso Sepúlveda,
• Valentina Spampinato,
• Alexis Franquet,
• Thierry Conard,
• Philippe M. Vereecken,
• Wilfried Vandervorst and
• Umberto Celano

Beilstein J. Nanotechnol. 2018, 9, 1623–1628, doi:10.3762/bjnano.9.154

• , which can be attributed to the dielectric breakdown of the film. High vacuum condition can be achieved (see below in Figure 3a) by working with a dedicated tool combining AFM and time-of-flight SIMS (TOF-SIMS) in the same apparatus (10−6 mbar or lower, TOF-SIMS V, ION-TOF GmbH, Münster, Germany). The

Light extraction efficiency enhancement of flip-chip blue light-emitting diodes by anodic aluminum oxide

• Yi-Ru Huang,
• Yao-Ching Chiu,
• Kuan-Chieh Huang,
• Shao-Ying Ting,
• Po-Jui Chiang,
• Chih-Ming Lai,
• Chun-Ping Jen,
• Snow H. Tseng and
• Hsiang-Chen Wang

Beilstein J. Nanotechnol. 2018, 9, 1602–1612, doi:10.3762/bjnano.9.152

• to clearly explain the reduction in total reflectivity and the existence of the surface plasmon wave in the samples. RCWA is a semianalytical method in computational electromagnetics that is typically applied to solve scattering from periodic dielectric structures [46]. Figure 9a shows the sample

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

• , Russia 10.3762/bjnano.9.145 Abstract We have experimentally investigated the effect of the reorientation of a nematic liquid crystal (LC) in an electric field on the photoluminescence (PL) of CdSe/ZnS semiconductor quantum dots (QDs). To the LC with positive dielectric anisotropy, 1 wt % QDs with a core

• significantly changes their optical properties [6][7][8][9][10]. To control the properties of NPs, they are introduced into a passive or active matrix interacting with them. Liquid crystals can be an active matrix for NPs. The dielectric and optical properties of a liquid crystal (LC) vary under electromagnetic

• spectral luminescence properties of the nematic LCs with a positive dielectric anisotropy doped with semiconductor CdSe/ZnS quantum dots [18][19][20]. The luminescence quenching of a planar oriented liquid crystal depended not only on the size but also on the concentration of QDs [18]. The PL intensity of

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

• dopant ionization energies increase, which decreases exponentially the free carrier density [1]. If a doped Si-nanovolume is embedded in a matrix of lower permittivity (e.g., a dielectric), the dopant charge is not fully screened in the silicon and a Coulomb interaction with its image charge in the

• dielectric occurs. Irrespective of quantum confinement, this so-called dielectric confinement increased the dopant ionization energy even further [2]. At the nanoscale, the incorporation of an impurity on a lattice site is also subject to an increased formation energy as compared to the bulk, so that despite

• attributed to dielectric relaxation, the P-doped Si NC samples clearly show mobile charge redistributions on a longer timescale. For the B-doped Si NCs the situation is less clear, since the noise level is reached earlier. A likely cause for this behaviour might be a lower density of redistributable charge

Cathodoluminescence as a probe of the optical properties of resonant apertures in a metallic film

• Kalpana Singh,
• Evgeniy Panchenko,
• Babak Nasr,
• Amelia Liu,
• Lukas Wesemann,
• Timothy J. Davis and
• Ann Roberts

Beilstein J. Nanotechnol. 2018, 9, 1491–1500, doi:10.3762/bjnano.9.140

• radiated power to position confined to the central region defined by the slots. We can gain further insight by examining the electric field produced inside the cavities on resonance when excited by a centred dipole and the accompanying surface charge on the dielectric–metal or air–dielectric boundary

• distance of 5 nm above the lower surface of the gold film at wavelengths of (a) 680 nm and (b) 800 nm. The (instantaneous) surface charge densities on the metal–dielectric boundary at wavelengths of (c) 600 nm and (d) 800 nm are also shown. Supporting Information Supporting Information File 114

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

• , University of New South Wales, Canberra, ACT 2600, Australia 10.3762/bjnano.9.139 Abstract Nonradiating current configurations have been drawing the attention of the physics community for many years. It has been demonstrated recently that dielectric nanoparticles provide a unique platform to host such

• focused beams enable us to excite ideal anapole modes of magnetic type in dielectric nanoparticles. Firstly, we perform the decomposition of this type of excitation into its multipolar content and then we employ the T-matrix method to calculate the far-field scattering properties of nanoparticles

• illuminated by such beams. We propose several configuration schemes where magnetic anapole modes of simple or hybrid nature can be detected in silicon nanospheres, nanodisks and nanopillars. Keywords: anapole excitation; dielectric nano-optics; multipolar expansion; T-matrix method; vector beams

Tailoring polarization and magnetization of absorbing terahertz metamaterials using a cut-wire sandwich structure

• Hadi Teguh Yudistira,
• Shuo Liu,
• Tie Jun Cui and
• Han Zhang

Beilstein J. Nanotechnol. 2018, 9, 1437–1447, doi:10.3762/bjnano.9.136

• study of optical metamaterials. The materials consist of multiple tiny metallic structures fabricated on dielectric substrates for metamaterial applications. The length of the tiny metallic structures of terahertz metamaterials is usually approximately hundreds of micrometers [12][13][14], which is much

• the background, and the metamaterial structure. The two parts are separated by a dielectric spacer. Another necessary condition found was that absorbers can be achieved by increasing the imaginary part of the refractive index and matching the impedance of the metamaterial with air impedance [24][25

• illustrates the geometry of the cut-wire sandwich structure. The width of the gold metallic bar (W), the length of gold metallic bar (L), the gap size between two unit cells (g), the thickness of the gold metallic bar (Zg), the thickness of the dielectric (polyimide (PI)) (Zd), and the lattice constant (D = L

Nanoporous silicon nitride-based membranes of controlled pore size, shape and areal density: Fabrication as well as electrophoretic and molecular filtering characterization

• Axel Seidenstücker,
• Stefan Beirle,
• Fabian Enderle,
• Paul Ziemann,
• Othmar Marti and
• Alfred Plettl

Beilstein J. Nanotechnol. 2018, 9, 1390–1398, doi:10.3762/bjnano.9.131

• material is fixed [14][15][16][17][18]. To avoid the latter restriction, the well-known preparation techniques of solid-state single pores (by focused ion or electron beams or recently by dielectric breakdown) are superior [10][19][20]. However, their sequential approach to generate arrays of highly

Disorder-induced suppression of the zero-bias conductance peak splitting in topological superconducting nanowires

• Jun-Tong Ren,
• Hai-Feng Lü,
• Sha-Sha Ke,
• Yong Guo and
• Huai-Wu Zhang

Beilstein J. Nanotechnol. 2018, 9, 1358–1369, doi:10.3762/bjnano.9.128

• interactions between the bound charges in the dielectric surroundings and the free charges in the nanowire [55], a finite leakage out of the Majorana modes due to the presence the normal drain [59], a finite coherence length in the induced superconducting pairing [60], and the orbital magnetic effects [61

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

• , Institute of Chemistry, Martin Luther University Halle-Wittenberg, 06120 Halle, Germany 10.3762/bjnano.9.121 Abstract Two homologue achiral bent-core liquid crystals (LCs), BCN66 and BCN84, in their nematic phases are studied by dielectric spectroscopy in the frequency range 10 Hz–10 MHz. In each of these

• dielectric strength and relaxation frequency for these processes are shown to give rise to sharpness in cluster boundaries, increased size and volume fraction in the LC nematic phase. The effect of the bias field on the LC cell is similar to reducing its temperature; both variables increase the cluster size

• and volume fraction and give rise to sharp cluster boundaries. The findings confirm that dielectric spectroscopy is a powerful and an extremely useful technique to provide a deeper understanding of the mechanism of cybotactic cluster formation in the isotropic liquid and the nematic phase of LCs as a