Surface-enhanced Raman scattering of water in aqueous dispersions of silver nanoparticles

• Paulina Filipczak,
• Krzysztof Hałagan,
• Jacek Ulański and
• Marcin Kozanecki

Beilstein J. Nanotechnol. 2021, 12, 497–506, doi:10.3762/bjnano.12.40

• . Additionally, the differential spectra obtained by subtracting the water spectrum from the spectra of AgNPs dispersions are shown. The enhancement of the low wavenumber component in the spectrum acquired in the parallel polarization configuration (polarized OH stretching mode), located at 3200 cm−1, is visible

Spontaneous shape transition of Mn_xGe_1−x islands to long nanowires

• S. Javad Rezvani,
• Luc Favre,
• Gabriele Giuli,
• Yiming Wubulikasimu,
• Isabelle Berbezier,
• Augusto Marcelli,
• Luca Boarino and
• Nicola Pinto

Beilstein J. Nanotechnol. 2021, 12, 366–374, doi:10.3762/bjnano.12.30

• silicides as an indispensable part of microelectronics [14][15]. In particular, the manganese germanide phase Mn5Ge3 is a semimetallic compound that has attracted attention due to its giant magnetoresistance and large spin polarization, which make it a proper candidate for spintronics applications [16][17

The patterning toolbox FIB-o-mat: Exploiting the full potential of focused helium ions for nanofabrication

• Victor Deinhart,
• Lisa-Marie Kern,
• Jan N. Kirchhof,
• Sabrina Juergensen,
• Joris Sturm,
• Enno Krauss,
• Thorsten Feichtner,
• Sviatoslav Kovalchuk,
• Michael Schneider,
• Dieter Engel,
• Bastian Pfau,
• Bert Hecht,
• Kirill I. Bolotin,
• Stephanie Reich and
• Katja Höflich

Beilstein J. Nanotechnol. 2021, 12, 304–318, doi:10.3762/bjnano.12.25

•  7a–c, respectively. The extinction was measured for plane wave incident light of linear polarization. The polarization was chosen along the x axis as depicted in Figure 7e. This configuration and any other in-plane polarization excite the optically active Eu mode of the tetramer [59]. The plasmonic

Paper-based triboelectric nanogenerators and their applications: a review

• Jing Han,
• Nuo Xu,
• Yuchen Liang,
• Mei Ding,
• Junyi Zhai,
• Qijun Sun and
• Zhong Lin Wang

Beilstein J. Nanotechnol. 2021, 12, 151–171, doi:10.3762/bjnano.12.12

• polarization direction, TENGs can have four working modes [87], including vertical contact–separation (CS) mode, in-plane lateral-sliding (LS) mode, single-electrode (SE) mode, and freestanding triboelectric-layer (FT) mode, as shown in Figure 2a. In the vertical CS mode, a stack of two dielectric films is

Fusion of purple membranes triggered by immobilization on carbon nanomembranes

• René Riedel,
• Natalie Frese,
• Fang Yang,
• Martin Wortmann,
• Raphael Dalpke,
• Daniel Rhinow,
• Norbert Hampp and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2021, 12, 93–101, doi:10.3762/bjnano.12.8

• polarization modulator unit. Further SEM images were recorded using a Vega W-REM from Tescan. UV–vis data was further processed and evaluated using NanoScope Analysis 1.90 (Build R1.135067, Bruker Corporation, ibid.), ImageJ 1.51j8 (National Institutes of Health, USA) and Gwyddion 2.47. Graphs were plotted

Atomic layer deposited films of Al₂O₃ on fluorine-doped tin oxide electrodes: stability and barrier properties

• Hana Krýsová,
• Michael Neumann-Spallart,
• Hana Tarábková,
• Pavel Janda,
• Ladislav Kavan and
• Josef Krýsa

Beilstein J. Nanotechnol. 2021, 12, 24–34, doi:10.3762/bjnano.12.2

• exploring the electrochemical reduction of the FTO film itself resulting in metallic tin, as evidenced by the dark coloration of the samples after a prolonged polarization at −1.2 V, according to Equation 1: The AFM phase images of glass/FTO before and after electrochemical treatment (−1.2 V, 5 h, phosphate

• polarization at −1.2 V vs Ag/AgCl, the reduction of FTO to tin took place (Equation 1). No Sn was found when the FTO layers were protected by alumina films (Figure 9). Conclusion ALD Al2O3 films, already at a thickness of 5 nm, exhibited very good blocking of the electron transport from solid electrodes (FTO

• bare FTO substrates and of Al2O3 layers on FTO substrates after polarization at −1.2 V vs Ag/AgCl, in buffer (pH 7.2) at different time intervals.a Supporting Information Supporting Information File 28: Additional figures. Acknowledgements The authors would like to thank Tim Verhagen for ellipsometry

Kondo effects in small-bandgap carbon nanotube quantum dots

• Patryk Florków,
• Damian Krychowski and
• Stanisław Lipiński

Beilstein J. Nanotechnol. 2020, 11, 1873–1890, doi:10.3762/bjnano.11.169

• . In the 1e region there are a spin Kondo effect with the fluctuating states |0↓⟩ and |0↑⟩ exhibiting orbital polarization, a valley Kondo effect with the |0↓⟩ and |↓0⟩ states exhibiting spin polarization, and a spin–valley Kondo effect with fluctuations of |↓0⟩ and |0↑⟩, in which both spin and orbital

• the SU(4) point in the 1e valley and the SU(3) point in the 3e valley. As already mentioned, the examples presented above do not exhaust all possible locations of high-symmetry points. Figure 3a presents an example of spin polarization of conductance corresponding to the conduction map in Figure 2c

• plotted ground-state diagrams of (a) CNTQD(24,21), (b) CNTQD(39,24), (c) CNTQD(15,12), and d) CNTQD(48,18) (U = 6 meV, Γ = 0.03 meV, δ = 1 meV·nm, β = 37 meV·nm2). (a, b) Spin polarization (SPC) and orbital polarization (OPC) maps of CNTQD(15,12). (c, d) Spin (MZ) and orbital pseudospin (TZ) magnetization

Piezotronic effect in AlGaN/AlN/GaN heterojunction nanowires used as a flexible strain sensor

• Jianqi Dong,
• Liang Chen,
• Yuqing Yang and
• Xingfu Wang

Beilstein J. Nanotechnol. 2020, 11, 1847–1853, doi:10.3762/bjnano.11.166

• effect; strain sensors; strain tests; top-down method; Introduction Due to the non-centrosymmetric structure of the group-III nitride semiconductor materials (e.g., GaN, AlN, and AlGaN), spontaneous polarization (Psp) and piezoelectric polarization induced by lattice mismatch (Plm) are inevitably

• introduced during the epitaxial growth process [1][2][3]. Furthermore, the analysis of the internal polarization of the AlGaN/AlN/GaN heterojunction showed the existence of a 2D electron gas (2DEG), which effectively suppresses the degradation of the carrier mobility caused by the scattering at charge

• polarization distribution inside the heterojunction [7][8]. The piezotronic effect, described first by Zhong Lin Wang in 2007, is a combination of the piezoelectric effect and the properties of non-centrosymmetric semiconductor materials [9]. 1D semiconductor nanowires (NWs) are more suitable candidates for

Absorption and photoconductivity spectra of amorphous multilayer structures

• Oxana Iaseniuc and
• Mihail Iovu

Beilstein J. Nanotechnol. 2020, 11, 1757–1763, doi:10.3762/bjnano.11.158

• build photodetectors with different signs of the photocurrent. This phenomenon of photocurrent sign inversion through polarization was also observed for photodetectors based on ZnAs2 anisotropic crystals [18]. Figure 8 shows that, besides the main peaks in the spectral distribution of the photocurrent

A self-powered, flexible ultra-thin Si/ZnO nanowire photodetector as full-spectrum optical sensor and pyroelectric nanogenerator

• Liang Chen,
• Jianqi Dong,
• Miao He and
• Xingfu Wang

Beilstein J. Nanotechnol. 2020, 11, 1623–1630, doi:10.3762/bjnano.11.145

• develop a new type of full-spectrum flexible PDs with a special working mechanism to further improve their performance and expand the practical application. Pyroelectric polarization can be achieved by changing the temperature of a pyroelectric material [10]. ZnO is an ideal pyroelectric material with a

• through the heterojunction is zero, and no current flows through the external circuit. However, upon illumination, a photothermally induced instantaneous temperature increase () will lead to the generation of a pyroelectric polarization potential and pyroelectric polarization charges at both ends of the c

• -axis of the ZnO NWs (Figure 2, middle). Because the direction of the pyroelectric electric field (Epy) is the same as Eb and the barrier height decreases at the heterojunction interface due to the generation of a negative polarization potential, the total electric field in the depletion zone increases

Detecting stable adsorbates of (1S)-camphor on Cu(111) with Bayesian optimization

• Jari Järvi,
• Patrick Rinke and
• Milica Todorović

Beilstein J. Nanotechnol. 2020, 11, 1577–1589, doi:10.3762/bjnano.11.140

• fast to compute, but they cannot accurately model hybrid materials, in which atomic interactions often feature a mixture of covalent and dispersive bonding, with charge transfer and polarization effects. Instead, we must employ quantum mechanical methods, such as density-functional theory (DFT) [12][13

Optically and electrically driven nanoantennas

• Monika Fleischer,
• Dai Zhang and
• Alfred J. Meixner

Beilstein J. Nanotechnol. 2020, 11, 1542–1545, doi:10.3762/bjnano.11.136

• -power excitation of nanoantennas, higher order contributions to the particle polarization are no longer negligible, and nonlinear effects become apparent. Due to their inherent symmetry breaking, nanoantennas can act as local sources of second harmonic generation (SHG) with attractive applications in

• revealing local structural properties is illustrated in [49], where crystalline and amorphous regions within core–shell silicon nanowires are discerned with an optical resolution of a few nanometers. This study further demonstrates that it is possible to combine polarization angle-resolved experiments with

• ][51]. A recent example of the strong coupling between silver nanorods and photochromic molecules is demonstrated in [52]. Due to the high local field intensity in the gap of a nanodimer, strong polarization of the particle, and consequently, strong SHG from the particle surface, may be expected

Controlling the electronic and physical coupling on dielectric thin films

• Philipp Hurdax,
• Michael Hollerer,
• Larissa Egger,
• Georg Koller,
• Xiaosheng Yang,
• Anja Haags,
• Serguei Soubatch,
• Frank Stefan Tautz,
• Mathias Richter,
• Alexander Gottwald,
• Peter Puschnig,
• Martin Sterrer and
• Michael G. Ramsey

Beilstein J. Nanotechnol. 2020, 11, 1492–1503, doi:10.3762/bjnano.11.132

• than the critical work function, as the latter is related to the electron affinity of the neutral twisted molecule, while the former is associated with the EA of the planar conformation. Increasing MgO thickness decreases the EA due to reduced polarization [20]. The Φcrit is reduced to such a low value

Impact of fluorination on interface energetics and growth of pentacene on Ag(111)

• Qi Wang,
• Meng-Ting Chen,
• Antoni Franco-Cañellas,
• Bin Shen,
• Thomas Geiger,
• Holger F. Bettinger,
• Frank Schreiber,
• Ingo Salzmann,
• Alexander Gerlach and
• Steffen Duhm

Beilstein J. Nanotechnol. 2020, 11, 1361–1370, doi:10.3762/bjnano.11.120

• or PFP with a flat-lying (long and short molecular axes parallel to the substrate) orientation, which have IEs (in monolayers on graphite) of 5.65 eV and 6.20 eV, respectively [25][26]. The decrease in the IE is due to solid state polarization, which is a general phenomenon for molecular thin films

• contribution polarization [11][44]. Perfluorination does not impact the orientation of PEN and PFP in the contact layer with clean metals, where both compounds are lying flat [9][30][31][47][48][49][50][51][52]. On Au(111), the coupling strength of both monolayers with the substrate is rather similar and

• effect [10][72][89] or, more generally, on the electronic polarization of the charged molecules on the surfaces. In addition to the substrate contribution, interactions with neighboring molecules, which have an electrostatic and an induction contribution, have to be taken into account [11][44]. Induction

Atomic defect classification of the H–Si(100) surface through multi-mode scanning probe microscopy

• Jeremiah Croshaw,
• Thomas Dienel,
• Taleana Huff and
• Robert Wolkow

Beilstein J. Nanotechnol. 2020, 11, 1346–1360, doi:10.3762/bjnano.11.119

• covalent interaction between the surface DB and the H or Si atom of the tip [39][44][45]. Since the surface DB is negatively charged at 0 V, an additional attractive interaction due to the polarization of the tip is also expected to contribute to the strength of the attractive interaction [45]. To

Role of redox-active axial ligands of metal porphyrins adsorbed at solid–liquid interfaces in a liquid-STM setup

• Thomas Habets,
• Sylvia Speller and
• Johannes A. A. W. Elemans

Beilstein J. Nanotechnol. 2020, 11, 1264–1271, doi:10.3762/bjnano.11.110

• solutions of molecules to the sample surface in an STM setup, the observed current between the tip and sample can increase. This increase may, for example, be the result of a mechanical disturbance made to the system upon adding the liquid, the presence of ions in the solution, and/or polarization of the

• (not shown). This observation implies that it is not exclusively the solvent that is responsible for the current. The observed behavior can have different causes. For example, due to the polarization of the solvent and/or the solutes therein, a current may flow from the tip to the sample or vice versa

• . Such a polarization may be triggered by a voltage change. However, it can be expected that when the voltage after the change remains constant, after a certain time a new equilibrium will be reached in which the flow of charges has died out and the additional current decays to zero. In the case of the

High permittivity, breakdown strength, and energy storage density of polythiophene-encapsulated BaTiO₃ nanoparticles

• Adnanullah Khan,
• Amir Habib and
• Adeel Afzal

Beilstein J. Nanotechnol. 2020, 11, 1190–1197, doi:10.3762/bjnano.11.103

• to 1 MHz. The dielectric loss of BTO nanoparticles is reduced to half by PTh coating in BTO-PTh nanoparticles, which is attributed to conduction loss and smaller interfacial polarization due to good compatibility between the two phases [26]. These results agree well with the calculated ac

Revealing the local crystallinity of single silicon core–shell nanowires using tip-enhanced Raman spectroscopy

• Marius van den Berg,
• Ardeshir Moeinian,
• Arne Kobald,
• Yu-Ting Chen,
• Anke Horneber,
• Steffen Strehle,
• Alfred J. Meixner and
• Dai Zhang

Beilstein J. Nanotechnol. 2020, 11, 1147–1156, doi:10.3762/bjnano.11.99

• , Germany 10.3762/bjnano.11.99 Abstract Tip-enhanced Raman spectroscopy is combined with polarization angle-resolved spectroscopy to investigate the nanometer-scale structural properties of core–shell silicon nanowires (crystalline Si core and amorphous Si shell), which were synthesized by platinum

• microscopy images. Additionally, the polarizations of Raman scattering and the photoluminescence signal from the tip–sample nanogap are explored by combining polarization angle-resolved emission spectroscopy with tip-enhanced optical spectroscopy. Our work demonstrates the significant potential of resolving

• local structural properties of Si nanomaterials at the sub-10 nanometer scale using tip-enhanced Raman techniques. Keywords: core–shell nanowires; local crystallinity; polarization angle-resolved spectroscopy; silicon; tip-enhanced Raman spectroscopy; Introduction The properties of silicon are long

Excitonic and electronic transitions in Me–Sb₂Se₃ structures

• Nicolae N. Syrbu,
• Victor V. Zalamai,
• Ivan G. Stamov and
• Stepan I. Beril

Beilstein J. Nanotechnol. 2020, 11, 1045–1053, doi:10.3762/bjnano.11.89

• symmetry in the Brillouin zone (k = 0) for crystals with an orthorhombic symmetry (Рnma). The photoelectric properties of the Me–Sb2S3 structures were investigated in the spectral range 1–1.8 eV under E||c and E⟂c polarization conditions and at different applied voltages. Keywords: anisotropy; antimony

• d = 113 μm) measured at different temperatures (300–11 K) under Е||с and Е⟂с polarization conditions. The results demonstrate that the absorption edge is shifted towards higher energies when the temperature decreases. The largest difference in the absorption edge (Еed) values is observed at ≈2·103

• polarization conditions, is formed due to the electronic transitions from different valence bands to a conduction band. Estimated values for the edge positions can be obtained by extrapolating the absorption curve to the energy axis, as shown by the black dotted lines in Figure 2. Figure 3A illustrates the

A new photodetector structure based on graphene nanomeshes: an ab initio study

• Babak Sakkaki,
• Hassan Rasooli Saghai,
• Ghafar Darvish and
• Mehdi Khatir

Beilstein J. Nanotechnol. 2020, 11, 1036–1044, doi:10.3762/bjnano.11.88

• approximation. In photocurrent calculations, we deal with photon–electron interaction, and according to the polarization of the incoming light, there is a possibility of transferring electrons with different spins (Equation 8). A linear photon polarization in the X-direction is assumed for the calculations of

Electrochemical nanostructuring of (111) oriented GaAs crystals: from porous structures to nanowires

• Elena I. Monaico,
• Eduard V. Monaico,
• Veaceslav V. Ursaki,
• Shashank Honnali,
• Vitalie Postolache,
• Karin Leistner,
• Kornelius Nielsch and
• Ion M. Tiginyanu

Beilstein J. Nanotechnol. 2020, 11, 966–975, doi:10.3762/bjnano.11.81

• acidic electrolyte with another type of anion. A comparison of the polarization curves measured at the beginning of the anodization process of a GaAs(111)B crystal in 1 M HNO3 or 1.75 M NaCl electrolyte is presented in Figure 3B. It can be observed that current oscillations occur at applied potentials

• polarization curves measured at a scan rate of 50 mV·s−1 at the beginning of the anodization process of a GaAs(111)B crystal in 1 M HNO3 (curve 1) and 1.75 M NaCl (curve 2). (A) SEM image in cross section of a GaAs(111)B sample anodized at 3 V for 20 min in 1 M HNO3. (B, C) Top-view SEM images. PL spectra of

Atomic layer deposition for efficient oxygen evolution reaction at Pt/Ir catalyst layers

• Stefanie Schlicht,
• Korcan Percin,
• Stefanie Kriescher,
• André Hofer,
• Claudia Weidlich,
• Matthias Wessling and
• Julien Bachmann

Beilstein J. Nanotechnol. 2020, 11, 952–959, doi:10.3762/bjnano.11.79

• day in a 1.6 M vanadium electrolyte (in H2SO4), followed by polarization to values between 0.3 and 1.6 V (five voltammetric cycles, 5 mV·s−1, approximately 43 min). Figure 5a shows that the samples obtained with the thermal decomposition method suffer a loss of activity upon storage, followed by a

• further subsequent loss upon polarization (8% overall). Their ALD counterparts, however, remain unaffected (Figure 5b). Thus, a Pt/Ir catalyst coated with the ALD method on anodized felts results in a significant stability gain with respect to the traditional thermal decomposition method of catalyst

• dashed line) and polarization in V (blue dotted line). Noble-metal loadings of the four samples presented in Figure 4, determined by ICP-OES analysis. Acknowledgements The authors thank Karin Faensen for the SEM-EDX measurements and Prof. Wolfgang Peukert and Paula Hoppe for ICP-OES analysis. Funding

Integrated photonics multi-waveguide devices for optical trapping and Raman spectroscopy: design, fabrication and performance demonstration

• Gyllion B. Loozen,
• Arnica Karuna,
• Mohammad M. R. Fanood,
• Erik Schreuder and
• Jacob Caro

Beilstein J. Nanotechnol. 2020, 11, 829–842, doi:10.3762/bjnano.11.68

• operation of the waveguides at 785 nm for the transverse magnetic (TM) polarization. For TM polarization, the electric field vector of the waveguide mode is directed perpendicular to the plane of the waveguide (the x–y plane, as indicated in Figure 1). This polarization is conserved in the emitted beam

• . For a multi-waveguide configuration as shown in Figure 1, the polarization of each beam then points in the same direction. For equal optical path lengths from the waveguide facets to the microbath center and for beams leaving the facets in phase, the light concentration in the center reaches the

• maximum obtainable value for the TM polarization, as a result of optimum constructive interference. For transverse electric (TE) polarization, for which the electric field vector of the beams is oriented in the x–y plane, the resulting light concentration is lower. In the simulations, the refractive

Epitaxial growth and superconducting properties of thin-film PdFe/VN and VN/PdFe bilayers on MgO(001) substrates

• Wael M. Mohammed,
• Igor V. Yanilkin,
• Amir I. Gumarov,
• Airat G. Kiiamov,
• Roman V. Yusupov and
• Lenar R. Tagirov

Beilstein J. Nanotechnol. 2020, 11, 807–813, doi:10.3762/bjnano.11.65

• magnetically soft, tunable and weak in the sense of small spin-polarization of the conduction band [10][28]. The latter provides a large superconducting coherence length and hence bypasses a necessity to deposit flat, nanometer-thick continuous layers expected for strong elemental ferromagnets. A combination

Nickel nanoparticles supported on a covalent triazine framework as electrocatalyst for oxygen evolution reaction and oxygen reduction reactions

• Secil Öztürk,
• Yu-Xuan Xiao,
• Dennis Dietrich,
• Beatriz Giesen,
• Juri Barthel,
• Jie Ying,
• Xiao-Yu Yang and
• Christoph Janiak

Beilstein J. Nanotechnol. 2020, 11, 770–781, doi:10.3762/bjnano.11.62

•  6a shows the OER polarization curves of the catalysts measured with a sweep rate of 5 mV/s at room temperature. We note that there should be a nickel oxidation process visible before the onset of the OER. Yet, the oxidation process of Ni for OER may be not evident [51][52]. Further, from XPS (Figure

• electrocatalytic ORR activity of the materials, polarization curves were collected in O2-saturated 1 mol/L KOH solution with a sweep rate of 10 mV/s at room temperature. The half-wave potentials are shown in Figure 8a. CTF-1-400, Ni/CTF-1-400-20 and Ni/CTF-1-400-35 show similar ORR polarization curves and their

• , (c) Ni/CTF-1-600-22 and (d) Ni/CTF-1-600-33. Ni atoms are depicted in red. Nitrogen adsorption and desorption isotherms (at 77 K) of Ni/CTF-1 composites. XPS measurements of Ni/CTF-1-600-22 with deconvoluted Ni 2p (left) (Sat. = satellite) and N 1s spectra (right). (a) OER polarization curves of