Adsorption and self-assembly of porphyrins on ultrathin CoO films on Ir(100)

• Feifei Xiang,
• Tobias Schmitt,
• Marco Raschmann and
• M. Alexander Schneider

Beilstein J. Nanotechnol. 2020, 11, 1516–1524, doi:10.3762/bjnano.11.134

• films on Ir(100) by scanning tunneling microscopy (STM) and density functional theory (DFT). The two substrates differ greatly with respect to their structural and potential-energy landscape corrugation with immediate consequences for adsorption and self-assembly of the molecules studied. On both films

• islands on the 2BL film. The findings demonstrate the guiding effect of the cobalt oxide films of different thickness and the effect of functional surface anchoring. Keywords: adsorption energy; molecular rotors; porphyrins; self-assembly; transition metal oxides; Introduction Due to their variability

• investigation of the structure and binding of porphyrins on semiconducting and, notably, metal oxide surfaces remains scarce [3][4][5][6][7][8][9][10][11][12][13]. We chose here to investigate two different porphyrins on thin films of cobalt(II) oxide (CoO). Cobalt(II) oxide not only is a semi-conducting oxide

Helium ion microscope – secondary ion mass spectrometry for geological materials

• Matthew R. Ball,
• Richard J. M. Taylor,
• Joshua F. Einsle,
• Fouzia Khanom,
• Christelle Guillermier and
• Richard J. Harrison

Beilstein J. Nanotechnol. 2020, 11, 1504–1515, doi:10.3762/bjnano.11.133

• minimum, for example, lapping films, they may not yield a polish smooth as lapping cloths do. As a result, it is almost impossible to satisfy both requirements. The recommendation should be to minimize relief as much as possible using appropriate preparation techniques for the sample before a final polish

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

• ), 10587 Berlin, Germany 10.3762/bjnano.11.132 Abstract Ultrathin dielectric/insulating films on metals are often used as decoupling layers to allow for the study of the electronic properties of adsorbed molecules without electronic interference from the underlying metal substrate. However, the presence

• (6P) on ultrathin MgO(100) films supported on Ag(100) is reported. By deliberately changing the work function of the MgO(100)/Ag(100) system, it is shown that the charge transfer (electronic coupling) into the 6P molecules can be controlled, and 6P monolayers with uncharged molecules (Schottky–Mott

• regime) and charged and uncharged molecules (Fermi level pinning regime) can be obtained. Furthermore, it was found that charge transfer and temperature strongly influence the orientation, conformation, and wetting behavior (physical coupling) of the 6P layers on the MgO(100) thin films. Keywords

Self-assembly and spectroscopic fingerprints of photoactive pyrenyl tectons on hBN/Cu(111)

• Domenik M. Zimmermann,
• Knud Seufert,
• Luka Ðorđević,
• Tobias Hoh,
• Sushobhan Joshi,
• Tomas Marangoni,
• Davide Bonifazi and
• Willi Auwärter

Beilstein J. Nanotechnol. 2020, 11, 1470–1483, doi:10.3762/bjnano.11.130

• properties in organic layers relied on bulk insulator supports [14][15][16]. As a promising alternative to bulk insulators, ultrathin dielectric films can act as decoupling layers but maintain the possibility to perform STM and STS measurements [17]. Atomically-thin hBN sheets attracted considerable interest

• at the submolecular level via STM and STS, e.g., reveal to be close to the gas-phase-like frontier orbitals. The electronic landscape of the hBN/Cu(111) template induces a periodic modulation of the electronic structure of the pyrene films at the single digit nanometer scale. The on-surface STM/STS

• molecular adsorption (Figure S11, Supporting Information File 1), open-porous structures would feature a smaller work function shift compared to densely packed molecular films. In the absence of charge transfer, the work function was assumed to decrease upon the adsorption of pyrenes on hBN/Cu(111) [84

Antimicrobial metal-based nanoparticles: a review on their synthesis, types and antimicrobial action

• Matías Guerrero Correa,
• Fernanda B. Martínez,
• Cristian Patiño Vidal,
• Camilo Streitt,
• Juan Escrig and
• Carol Lopez de Dicastillo

Beilstein J. Nanotechnol. 2020, 11, 1450–1469, doi:10.3762/bjnano.11.129

• setup [23]. Magnetron sputtering is a high-rate vacuum-coating technique generally used to synthesize films, multilayer or hybrid systems based on substrate coating. For example, Piedade et al. obtained ZnO, ZnO–C and ZnO–Cu films with thickness values ranging from 385 to 1635 nm. In addition, Galstyan

• thickness values of approximately 20 and 17 nm, respectively [38][39]. ALD has been recognized as a key technique used to deposit thin films on structures with complex geometries, allowing for the synthesis of nanostructures without shadowing effects and with a high aspect ratio, such as nanotubes with

Wafer-level integration of self-aligned high aspect ratio silicon 3D structures using the MACE method with Au, Pd, Pt, Cu, and Ir

• Mathias Franz,
• Romy Junghans,
• Paul Schmitt,
• Adriana Szeghalmi and
• Stefan E. Schulz

Beilstein J. Nanotechnol. 2020, 11, 1439–1449, doi:10.3762/bjnano.11.128

• discussed in detail. Particle formation The surface of the deposited noble metal films has been analysed before and after the thermal annealing using a scanning electron microscope (SEM). The generated particles have been analysed using “ImageJ” [24] with the package collection “Fiji” [25]. For the analysis

• , we used images with a magnification of 100.000×, where each pixel has a size of 1.1 nm/pixel. The analysed area of each image has a size of 1024 × 703 pixel2, which represents 1126 × 773 nm2 = 0.89 μm2. Initially, the sputtered metals formed continuous films with randomly distributed pinholes at the

• with 45 cycles. The Ir samples were not annealed thermally. The given scale bar is representative for all SEM images within this figure. The metal films have segregated into small particles on the Si surface. For the analysis, we approximated the particles with the best fitting ellipses. The calculated

Protruding hydrogen atoms as markers for the molecular orientation of a metallocene

• Linda Laflör,
• Michael Reichling and
• Philipp Rahe

Beilstein J. Nanotechnol. 2020, 11, 1432–1438, doi:10.3762/bjnano.11.127

• holder. To reduce residual charge on the surface [25], the sample was heated at about 330 K for one hour prior to the deposition of the ferrocene molecules and NC-AFM experiments. Thin CaF2 films were prepared by deposition of CaF2 (purity 99.9%, Alfa Aesar, Kandel, Germany) from an EFM3T e-beam

• determined by considering the B-type epitaxy of the CaF2/CaF1/Si(111) thin films samples, see [22][26] for further details. STM and NC-AFM experiments were conducted at low temperatures (5 and 77 K) in two separate systems. Experiments on bulk crystals were performed using an Omicron LT qPlus gen.III

• instrument (ScientaOmicron GmbH, Taunusstein, Germany), while experiments on thin films used a ScientaOmicron LT qPlus gen.II machine, both operated with a MATRIX controller. W tips attached to tuning fork sensors in qPlus configuration [29] were used in both systems. For the measurements on thin film

One-step synthesis of carbon-supported electrocatalysts

• Sebastian Tigges,
• Nicolas Wöhrl,
• Ivan Radev,
• Ulrich Hagemann,
• Markus Heidelmann,
• Thai Binh Nguyen,
• Stanislav Gorelkov,
• Stephan Schulz and
• Axel Lorke

Beilstein J. Nanotechnol. 2020, 11, 1419–1431, doi:10.3762/bjnano.11.126

• commercial production of fuel cell catalysts, especially the scarcity of noble metals and the insufficient electrochemical long-term stability. Even though the surface-to-volume ratio can be drastically increased by the use of nanoparticles instead of thin films, the amount of noble metal (usually platinum

Superconductor–insulator transition in capacitively coupled superconducting nanowires

• Alex Latyshev,
• Andrew G. Semenov and
• Andrei D. Zaikin

Beilstein J. Nanotechnol. 2020, 11, 1402–1408, doi:10.3762/bjnano.11.124

• case of superconducting nanowires QPT was described [5] with the aid of RG equations equivalent to those initially developed for two-dimensional superconducting films [29] which exhibit classical Berezinskii–Kosterlitz–Thouless (BKT) phase transition driven by temperature. In contrast, quantum SIT in

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

• ]. Fluorination is a viable way to change the ionization energies (IEs) of organic semiconductor thin films [4][5][6], which are an important parameter for energy level alignment [7][8]. Moreover, at organic–metal interfaces, fluorination is believed to decrease the coupling strength between the substrate and the

• ][30][31][32][33][34][35]. PEN and PFP have almost identical optical gaps in thin films (1.85 eV and 1.75 eV, respectively) [36][37], and the experimental gas phase IEs (measured by UPS) are 6.59 eV [38] and 7.50 eV [39], respectively. This trend of the IEs is also found for thin films comprised of PEN

• 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

Controlling the proximity effect in a Co/Nb multilayer: the properties of electronic transport

• Sergey Bakurskiy,
• Mikhail Kupriyanov,
• Nikolay V. Klenov,
• Igor Soloviev,
• Andrey Schegolev,
• Roman Morari,
• Yury Khaydukov and
• Anatoli S. Sidorenko

Beilstein J. Nanotechnol. 2020, 11, 1336–1345, doi:10.3762/bjnano.11.118

• the conditions at which switching from the parallel to the antiparallel alignment of the neighboring F-layers leads to a significant change of the superconducting order parameter in superconductive thin films. We experimentally study the transport properties of a lithographically patterned Nb/Co

• between two neighboring films of ferromagnetic layers grown using cobalt (99.95% purity). Pure silicon (99.999%) was the third target used to create a passivating layer to prevent structure oxidation. The details regarding the deposition technology were previously described [27]. The structure for the

Effect of localized helium ion irradiation on the performance of synthetic monolayer MoS₂ field-effect transistors

• Jakub Jadwiszczak,
• Pierce Maguire,
• Conor P. Cullen,
• Georg S. Duesberg and
• Hongzhou Zhang

Beilstein J. Nanotechnol. 2020, 11, 1329–1335, doi:10.3762/bjnano.11.117

• of well-performing monolayer TMD films [3][4][5], leading to viable large-scale integration of on-chip TMD FETs. With device miniaturization, it becomes key to understand the impact of defects such as chalcogen vacancies on the electrical transport properties of FETs based on 2D semiconductors. This

Structural and electronic properties of SnO₂ doped with non-metal elements

• Jianyuan Yu,
• Yingeng Wang,
• Yan Huang,
• Xiuwen Wang,
• Jing Guo,
• Jingkai Yang and
• Hongli Zhao

Beilstein J. Nanotechnol. 2020, 11, 1321–1328, doi:10.3762/bjnano.11.116

• SnO2; electronic structure; optical properties; Introduction Thin film solar cells are devices that convert solar energy into electrical energy. Transparent conductive films (TCFs) are a thin film material with both conductive capabilities and high transmittance in the visible light range (300–800 nm

• SnO2 is not conductive due to the absence of free carriers. However, the bandgap of 3.6 eV of SnO2 makes it a potentially ideal material for transparent electrode films. It had been proved that the doping of heteroatoms to replace Sn or O can lead to more carriers or holes. Therefore, extensive

• preferred orientation, optical properties, and electrical properties of SnO2 film are improved. Analysis of the electrical properties of SnO2 films doped with different non-metal elements showed that the resistance of SnO2 films doped with N was higher [6][7][8] than that of SnO2 doped with other elements

Cryogenic low-noise amplifiers for measurements with superconducting detectors

• Ilya L. Novikov,
• Boris I. Ivanov,
• Dmitri V. Ponomarev and
• Aleksey G. Vostretsov

Beilstein J. Nanotechnol. 2020, 11, 1316–1320, doi:10.3762/bjnano.11.115

• Josephson junctions and superconducting thin films. Experimental studies of such sensors require the design of low-noise cryogenic readout electronics with a direct coupling to the sample. For example, investigations of noise sources in low-temperature tunnel Josephson junctions are still ongoing for high

Magnetohydrodynamic stagnation point on a Casson nanofluid flow over a radially stretching sheet

• Ganji Narender,
• Kamatam Govardhan and
• Gobburu Sreedhar Sarma

Beilstein J. Nanotechnol. 2020, 11, 1303–1315, doi:10.3762/bjnano.11.114

• several industry sectors, such as drawing of plastic films, manufacturing of glass, production of paper, and refining crude oil. Recently, many researchers have been focusing their attention on nanoparticles, since they exhibit remarkable electrical, optical, and chemical properties in addition to having

Growth of a self-assembled monolayer decoupled from the substrate: nucleation on-command using buffer layers

• Robby Reynaerts,
• Kunal S. Mali and
• Steven De Feyter

Beilstein J. Nanotechnol. 2020, 11, 1291–1302, doi:10.3762/bjnano.11.113

• formation by acting as a physical barrier between the substrate and the assembling moiety, buffer layers are also widely used to study intrinsic electronic properties of functional organic systems such as organic semiconductors [32][33] and films of 1D/2D polymers [34][35][36][37] via electronic decoupling

• ], NaCl [40], CuN [41] and oxides [32][42] have been used. Typically, the ultrathin films of these wide band gap materials act as insulating layers while still allowing electron tunneling through them. Chemisorbed iodine layers have been used as passivating layers on metals such as Au for achieving

Proximity effect in [Nb(1.5 nm)/Fe(x)]₁₀/Nb(50 nm) superconductor/ferromagnet heterostructures

• Yury Khaydukov,
• Sabine Pütter,
• Laura Guasco,
• Roman Morari,
• Gideok Kim,
• Thomas Keller,
• Anatolie Sidorenko and
• Bernhard Keimer

Beilstein J. Nanotechnol. 2020, 11, 1254–1263, doi:10.3762/bjnano.11.109

• still possible, y ≈ 3 nm, is still two times smaller than the minimum thickness ≈ 6–8 nm of thin Nb films in which superconductivity appears [19][20]. In order to provide superconducting correlations in a Fe/Nb superlattice (SL) we propose to deposit the Fe/Nb SL on top of a thick Nb(40–50 nm) layer

Magnetic-field-assisted synthesis of anisotropic iron oxide particles: Effect of pH

• Andrey V. Shibaev,
• Petr V. Shvets,
• Darya E. Kessel,
• Roman A. Kamyshinsky,
• Anton S. Orekhov,
• Sergey S. Abramchuk,
• Alexei R. Khokhlov and
• Olga E. Philippova

Beilstein J. Nanotechnol. 2020, 11, 1230–1241, doi:10.3762/bjnano.11.107

• HR800, Villeneuve-d'Ascq, France) equipped with 100× magnification lens. The copper substrates were dip-coated in the sample solutions and dried under ambient conditions. The measurements of the produced films were conducted at room temperature and atmospheric air. A He–Ne laser (λ = 632.8 nm) was used

Gas sorption porosimetry for the evaluation of hard carbons as anodes for Li- and Na-ion batteries

• Yuko Matsukawa,
• Fabian Linsenmann,
• Maximilian A. Plass,
• George Hasegawa,
• Katsuro Hayashi and
• Tim-Patrick Fellinger

Beilstein J. Nanotechnol. 2020, 11, 1217–1229, doi:10.3762/bjnano.11.106

• area (SSA) of the anode materials as well as the deposition of amorphous carbon films were shown to reduce irreversible capacity losses [22][23]. Ji et al. found that lower total pore volumes (determined by N2 sorption) gave rise to increased reversible sodium storage capacities for sucrose-derived HCs

• (MTI corporation, USA) on an automatic table-top coating machine (Coatema, Germany) using the doctor blade method, resulting in a wet film thickness of 90 µm. The HC loading of the electrodes was 3 ± 0.1 mg cm−2. After drying the films in an oven at 50 °C for 3 h, electrodes with a diameter of 10.95 mm

Hybridization vs decoupling: influence of an h-BN interlayer on the physical properties of a lander-type molecule on Ni(111)

• Maximilian Schaal,
• Takumi Aihara,
• Marco Gruenewald,
• Felix Otto,
• Jari Domke,
• Roman Forker,
• Hiroyuki Yoshida and
• Torsten Fritz

Beilstein J. Nanotechnol. 2020, 11, 1168–1177, doi:10.3762/bjnano.11.101

• through different ways such as the usage of wide-band-gap insulator thin films (e.g., oxides, alkali halides) [3][4], a molecular spacer layer [5][6], or sp2-hybridized two-dimensional interlayers (e.g., graphene and hexagonal boron nitride (h-BN)) [7][8]. The advantageous properties of an h-BN monolayer

• on metal single crystals are the high crystal quality, chemical inertness and the wide band gap of approx. 6 eV, which apparently renders h-BN a promising candidate for the decoupling of highly ordered molecular films [9][10]. However, indications for a significant hybridization of organic molecules

• The ultraviolet photoelectron spectroscopy (UPS) measurements of the DBP films on Ni(111) and h-BN/Ni(111) are depicted in Figure 4. We use the notation proposed by Kirchhuebel et al. to assign spectroscopic features to the underlying molecular orbitals, taking into consideration the probing process

Scanning tunneling microscopy and spectroscopy of rubrene on clean and graphene-covered metal surfaces

• Karl Rothe,
• Alexander Mehler,
• Nicolas Néel and
• Jörg Kröger

Beilstein J. Nanotechnol. 2020, 11, 1157–1167, doi:10.3762/bjnano.11.100

• monatomically thin buffer layers (BLs) on metal surfaces, i.e., as intermediate films that efficiently reduce the hybridization of an adsorbate with the metallic substrate. The minimization of the adsorbate–substrate coupling is motivated by the desire to preserve genuine properties of the free atom or molecule

• this peak to the LUMO or LUMO+1. Much wider unoccupied molecular resonances have been observed, too, in pump–probe photoemission experiments on thin C42H28 films adsorbed on highly oriented pyrolithic graphite and traced to the elevated molecule–substrate hybridization with a concomitant reduced

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

• that polarized excitation Raman spectroscopy is useful to distinguish hydrogenated nano-crystalline silicon films (nc-Si) from a-Si and c-Si areas [24]. Although, Raman spectroscopy is an overall powerful tool to characterize the material properties of Si, this technique requires still an improvement

• of Si at about 520 cm−1 with the equation: In c-Si with cubic diamond structure, ΔΘ has a value of 0°, whereas in a-Si films ΔΘ was experimentally determined to be in the range of 7.7° ≤ ΔΘ ≤ 10.5°. In our experiments we calculated ΔΘavg,n-f = 9.2° and ΔΘavg,conf = 8.3° based on the near-field and

• results, which supports the idea that TERS can be used as a micro/nano-structure characterization technique. Experimental Core–shell SiNWs were synthesized in two steps. At first, SiNWs were grown by utilizing the VLS growth mechanism [13] using dewetted Pt thin films as the growth catalyst [29] at a

Photothermally active nanoparticles as a promising tool for eliminating bacteria and biofilms

• Mykola Borzenkov,
• Piersandro Pallavicini,
• Angelo Taglietti,
• Laura D’Alfonso,
• Maddalena Collini and
• Giuseppe Chirico

Beilstein J. Nanotechnol. 2020, 11, 1134–1146, doi:10.3762/bjnano.11.98

• after one round of laser exposure. Poly(vinyl alcohol) (PVA) films cross-linked with citric acid loaded with highly efficient photothermal gold nanostars were also fabricated [66]. The resulting films demonstrated a pronounced photothermal effect under NIR irradiation in the 730–1064 nm wavelength range

• . The local photothermal effect triggered by the NIR irradiation of PVA-GNS films was highly efficient in eliminating E. coli bacteria, as shown in Figure 4. In a very recent study, the antimicrobial activity of a chitosan-based hydrogel with embedded gold nanorods under low-power (200 mW) diode laser

• , physically cross-linked PVA hydrogel films, containing Prussian blue nanoparticles, displayed a pronounced photothermal effect (up to ΔT ≅ 78 °C) under low NIR laser intensities (0.3 W/cm2) [76]. The resulting local temperature increase was sufficient to eradicate ≈76% of P. aeruginosa bacteria and mitigate

Plant growth regulation by seed coating with films of alginate and auxin-intercalated layered double hydroxides

• Vander A. de Castro,
• Valber G. O. Duarte,
• Danúbia A. C. Nobre,
• Geraldo H. Silva,
• Vera R. L. Constantino,
• Frederico G. Pinto,
• Willian R. Macedo and
• Jairo Tronto

Beilstein J. Nanotechnol. 2020, 11, 1082–1091, doi:10.3762/bjnano.11.93

• diversity of crops and cultivation environments, it is necessary to seek more efficient modes of application, which lead to a homogeneous distribution and promote a sustained release according to the plants demand. Seed coating, using films containing a biodegradable polymer and auxins intercalated into

• auxin 1-naphthalenoacetic acid (ZnAl-NAA-LDH), (ii) the coating of bean seeds (Phaseolus vulgaris L.) with composite films produced from mixtures of alginate polymer and ZnAl-NAA-LDH, and (iii) the evaluation of the plant response by bioassays. The hybrid ZnAl-NAA-LDH was characterized by a set of

• , fresh root matter and shoot length of plants. Thus, films produced from a mixture of alginate and the hybrid material containing the growth regulator intercalated into LDH can be a viable alternative to enhance plant development, which can be included in seed management. Keywords: bioassays

Highly sensitive detection of estradiol by a SERS sensor based on TiO₂ covered with gold nanoparticles

• Andrea Brognara,
• Ili F. Mohamad Ali Nasri,
• Beatrice R. Bricchi,
• Andrea Li Bassi,
• Caroline Gauchotte-Lindsay,
• Matteo Ghidelli and
• Nathalie Lidgi-Guigui

Beilstein J. Nanotechnol. 2020, 11, 1026–1035, doi:10.3762/bjnano.11.87

• Procédés et des Matériaux (LSPM), CNRS, Université Sorbonne Paris Nord, 93430, Villetaneuse, France CSPBAT, UMR 7244, Université Sorbonne Paris Nord, 93430 Villetaneuse, France 10.3762/bjnano.11.87 Abstract We propose the use of gold nanoparticles grown on the surface of nanoporous TiO2 films as surface

• the plasmonic properties. Specifically, TiO2 films with different porosities have been deposited, with different Au NP sizes and coverages. Then, the growth parameters of TiO2 and of the AuNPs were selected in order to obtain the maximum SERS enhancement. In a second step, the Au NPs were

• . The thermal treatment was carried out to induce both crystallization of the as-deposited amorphous TiO2 into the anatase phase (as discussed in [28][29]) and the formation of AuNPs exploiting dewetting of the Au films. A field-emission scanning electron microscope (FEG-SEM, Zeiss Supra 40) was used to