Mapping of integrated PIN diodes with a 3D architecture by scanning microwave impedance microscopy and dynamic spectroscopy

• Rosine Coq Germanicus,
• Peter De Wolf,
• Florent Lallemand,
• Catherine Bunel,
• Serge Bardy,
• Hugues Murray and
• Ulrike Lüders

Beilstein J. Nanotechnol. 2020, 11, 1764–1775, doi:10.3762/bjnano.11.159

• ) (doped semiconducting layers) and “back end of line” (BEOL) layers (metallization, trench dielectric, and isolation) of highly integrated microelectronic devices. Based on atomic force microscopy, an electromagnetically shielded and electrically conductive tip is used in scanning microwave impedance

• architecture is analysed. sMIM measurements of the different layers of the PIN diode are presented and discussed in terms of detection mechanism, sensitivity, and precision. In the second part, supported by analytic calculations of the equivalent nano-MIS capacitor, a new multidimensional approach, including a

• complete parametric investigation, is performed with a dynamic spectroscopy method. The results emphasize the strong impact, in terms of distinction and location, of the applied bias on the local sMIM measurements for both FEOL and BEOL layers. Keywords: atomic force microscopy (AFM); DataCube; doping

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

• of the photocurrent spectra is attributed to the different values of the optical bandgap of the involved amorphous layers (Eg ≈ 2.0 eV for As0.40S0.30Se0.30 and Ge0.09As0.09Se0.82 and Eg ≈ 3.0 eV for Ge0.30As0.04S0.66). The obtained experimental results are discussed taking into account the light

• absorption depending on the nature and the thickness of each amorphous layer, on the wavelength, and on contact phenomena at the interfaces between different layers and between the amorphous layers and the metal electrodes with different work functions. Keywords: amorphous multilayer structures

• the incident visible light to reach the other layers with a bandgap energy of Eg ≈ 2.0 eV [12][13] and with a thicknesses of d ≈ 500 nm for Ge0.09As0.09Se0.82 and d ≈ 1000 nm for As0.40S0.30Se0.30. Figure 2 shows that the amorphous film Ge0.30As0.04S0.66 is highly transparent to incident light in the

Direct observation of the Si(110)-(16×2) surface reconstruction by atomic force microscopy

• Tatsuya Yamamoto,
• Ryo Izumi,
• Kazushi Miki,
• Takahiro Yamasaki,
• Yasuhiro Sugawara and
• Yan Jun Li

Beilstein J. Nanotechnol. 2020, 11, 1750–1756, doi:10.3762/bjnano.11.157

• the first and second layers are indicated by white and black circles, respectively. Red and yellow crossmarks indicate the dangling bonds observed in AFM images on the upper terrace and lower terrace, respectively. Some atoms are labelled as 1 to 5 for clarification. (b) The atomic model with atoms 1

Imaging and milling resolution of light ion beams from helium ion microscopy and FIBs driven by liquid metal alloy ion sources

• Nico Klingner,
• Gregor Hlawacek,
• Paul Mazarov,
• Wolfgang Pilz,
• Fabian Meyer and
• Lothar Bischoff

Beilstein J. Nanotechnol. 2020, 11, 1742–1749, doi:10.3762/bjnano.11.156

• thickness. Milling membranes removes their support from one side and dangling bonds can lead to morphological changes making milling tests difficult to interpret. In metal layers of a few nanometers thickness, sputter redeposition can take place, which is not taken into account in our static SRIM simulation

Functional nanostructures for electronics, spintronics and sensors

• Anatolie S. Sidorenko

Beilstein J. Nanotechnol. 2020, 11, 1704–1706, doi:10.3762/bjnano.11.152

• functional nanostructures consisting of alternating layers of ferromagnetic and superconducting materials – has been observed. Due to the proximity effect of superconductor/ferromagnetic (S/F) layers and Andreev reflection of Cooper pairs at the S/F interface, a number of new phenomena were first

Out-of-plane surface patterning by subsurface processing of polymer substrates with focused ion beams

• Serguei Chiriaev,
• Luciana Tavares,
• Vadzim Adashkevich,
• Arkadiusz J. Goszczak and
• Horst-Günter Rubahn

Beilstein J. Nanotechnol. 2020, 11, 1693–1703, doi:10.3762/bjnano.11.151

• direct, maskless surface patterning with a superior lateral resolution and depth control [2][3]. The portfolio of the currently used FIB-based and FIB-assisted surface patterning techniques includes a number of different methods, such as ion-beam sputtering of surface layers (ion-beam milling), ion-beam

• -assisted chemical etching and ion-beam-assisted chemical vapor deposition [1][2][3]. All these methods are based on processes that either add or remove atoms on the surface or in the subsurface atomic layers. The ion beams deposit their energy and, therefore, affect the structure and properties of

• ions and materials, such as structural damage and chemical modification that affect functional properties of the near-surface layers, are substantially reduced in comparison to FIB milling. Another advantage of the subsurface processing is that the local heating is negligible in comparison to ion

The influence of an interfacial hBN layer on the fluorescence of an organic molecule

• Christine Brülke,
• Oliver Bauer and
• Moritz M. Sokolowski

Beilstein J. Nanotechnol. 2020, 11, 1663–1684, doi:10.3762/bjnano.11.149

• ]. Specifically, the use of 2DMs in layered heterostructures has been promoted [2][3]. Here, one challenge lies in the understanding of not only the processes in the individual materials, but also of those that occur at the interfaces between layers of different materials. Advantageously, some 2DMs can be grown

• layer is to achieve a separation or “decoupling” of the two adjacent layers. Here, the term decoupling refers to the spatial separation of the electronic states of the molecules and those of the underlying metal, which leads to unperturbed molecular properties [4]. A scientifically relevant question is

• a 2DM layer grown on a metal characterizes the degree of electronic coupling of the molecular and metallic states. For completeness, we note that quenching of an electronic excitation of a molecule in the first layers on a metal surface can be the result of interfacial charge transfer (CT) [5] or of

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

• . Finally, by RF magnetron sputtering, a 200 nm thick layers of ITO and Cu were deposited on ZnO NWs and p-Si, respectively. Electrical measurements: the measurement setup includes a source meter, an optical platform, a chopper, sample, and a light source. Sample, chopper and light source must be in the

PTCDA adsorption on CaF₂ thin films

• Philipp Rahe

Beilstein J. Nanotechnol. 2020, 11, 1615–1622, doi:10.3762/bjnano.11.144

• modern applications, for example as a critical component in organic thin-film transistors [2]. However, and despite the success of using thin insulating NaCl films for molecular decoupling [3], it is now understood that ultrathin layers are often not sufficient to truly insulate a molecular assembly. To

• adsorption energies using the counterpoise method [39] were used. Geometry-optimisation calculations were performed for a single PTCDA molecule adsorbed on a (6 × 6) slab with a thickness of three CaF2 triple layers. The lowest triple layer was held fixed. A tolerance of 10−4 Ha/Bohr was used. Results and

• dissociated fluorine atoms mostly desorb from the surface, likely in the form of SixF molecules [28][29]. Thicker CaF2 layers can then be grown stoichiometrically on the interface layer by successive CaF2 deposition. The CaF1/Si(111) surface has a (1 × 1) termination after etching the Si(111)-(7 × 7

Walking energy harvesting and self-powered tracking system based on triboelectric nanogenerators

• Mingliang Yao,
• Guangzhong Xie,
• Qichen Gong and
• Yuanjie Su

Beilstein J. Nanotechnol. 2020, 11, 1590–1595, doi:10.3762/bjnano.11.141

• , nanostructured PTFE thin films coated with copper foils (back electrodes), and an elastic undulated electrode in between. The internal wave-shaped electrode is obtained by depositing copper layers onto both sides of the wave-shaped Kapton film, as displayed in Figure 1a. Due to their huge difference in electron

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

• structures are relaxed below a maximum force component of 10−2 eV/Å. We model the Cu substrate with a Cu(111) slab of four atomic layers and (6 × 4) orthogonal unit cells (192 atoms, lattice vectors [a, b, c] = [15.41, 17.79, 56.29] Å). The lattice constant of Cu is set to 3.632 Å, which we obtain from

• relaxed bulk Cu, in agreement with reference studies [50][51]. We construct the four-layer Cu slab by fixing the two bottom layers to their optimal layer separation (d34 = 2.097 Å, corresponding to bulk Cu). The two top layers are then relaxed, which results in a reduced layer separation (d12 = 2.076 Å

Fabrication of nano/microstructures for SERS substrates using an electrochemical method

• Jingran Zhang,
• Tianqi Jia,
• Xiaoping Li,
• Junjie Yang,
• Zhengkai Li,
• Guangfeng Shi,
• Xinming Zhang and
• Zuobin Wang

Beilstein J. Nanotechnol. 2020, 11, 1568–1576, doi:10.3762/bjnano.11.139

• . The depth and diameter of the nanopores gradually increased as the treatment time increased, as shown in Figure 2b,c. Figure 2d shows cross-sectional SEM images of arrayed nanopores. The surface morphology includes MgO and Mg layers. In addition, a clamp is used to fix the sample. As shown in Figure 2

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

• molecular adlayer, for example, by introducing elements that allow for strong anchoring [8][10][11][12][13]. This may, however, counteract the possibility to form ordered layers when, due to the enhanced molecule–substrate interaction, the molecules become immobile or the functional groups used as anchors

• -PAW general gradient approximation [33]. To account for dispersion forces the zero damping DFT-D3 correction of Grimme et al. was used [34]. Slabs were constructed from two layers of iridium and one or two bilayers of cobalt oxide. For the iridium lattice the relaxed DFT-D3 parameter (a = 3.835 Å) was

• Tersoff–Hamann approximation [36]. The projected density of states (PDOS) was calculated using the same parameters. To compare the molecular PDOS on the oxide to that on the bare Ir(100), Co-DPP was put on a bridge site on three layers of Ir. The molecule and two layers of Ir were allowed to relax but no

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

• sample is taken to this instrument, but this leads to the implantation of gallium ions and can lead to potential damage to the sample if an incorrect dose is used. Instead, care should be taken to apply thin (5–10 nm) coating layers to the sample, to maximise analysis time on the instrument. Sample

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

• of such decoupling layers may effectively change the electron donating properties of the substrate, for example, by lowering its work function and thus enhancing the charging of the molecular adsorbate layer through electron tunneling. Here, an experimental study of the charging of para-sexiphenyl

• 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

• as such spacer layers [18] and can promote site-dependent decoupling and adsorption [19][20], yielding access to optical transitions [21] as well as allowing for orbital-resolved STM imaging [19][21][22][23]. For instance, hBN/Cu(111) [24][25][26][27] features a work function template with a moiré

• (see Figure 6). Dissimilar responses of distinct MOs to work function variations were previously discussed, e.g., for pentacene on dielectric decoupling layers [23]. The assignment of the dI/dV signature to the MOs was corroborated by resolving the submolecular features in high-resolution STM images at

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

• polysaccharides; ii) Gram-positive bacteria contain many layers of peptidoglycan and teichoic acid (20–50 nm); and iii) Gram-negative bacteria present a few layers of peptidoglycan surrounded by a second lipid membrane containing lipopolysaccharides and lipoproteins [156][157]. Therefore, the cell wall damage

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

• layers have been patterned with standard photo-resist and a proximity lithography step. The selected full wafer pattern consists of a series of open quadratic test fields. These were transferred from the photo-resist to the PMMA layer using a reactive ion etching process with oxygen. In contrast to the

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

• imaging (such as TEM), ultrahigh resolution TEM images prove the formation of embedded Pt-NPs in the carbon matrix by resolving individual carbon layers, which are affected by the Pt-NP. In the left frame of Figure 3, it can be seen that the Pt-NP (blue) interrupts/disturbs some of the carbon layers

• (green), whereas one of the layers appears to bend around the Pt-NP (yellow arrow). In the right frame, the carbon layers split up as they pass around the Pt-NP (red arrow). Both of these phenomena and the improved electrochemical stability (see section “Electrochemically active surface area and long

• amorphous layer (Ar/H2 ≈59, Figure 4d, right panel). Raman spectroscopy was performed to determine the quality (defect density, defect type, and hybridization) of the deposited Pt/CNW layers. All samples produced at sufficiently high pressures and low carrier gas flow rates exhibit the typical spectrum

Analysis of catalyst surface wetting: the early stage of epitaxial germanium nanowire growth

• Owen C. Ernst,
• Felix Lange,
• David Uebel,
• Thomas Teubner and
• Torsten Boeck

Beilstein J. Nanotechnol. 2020, 11, 1371–1380, doi:10.3762/bjnano.11.121

• are fully understood yet, especially regarding metallic fluids, it is clear that the formation of nanometre-sized particles, droplets, and clusters as well as their movement are strongly linked to their wetting behaviour. For this reason, the thermodynamic stability of thin metal layers (0.1–100 nm

• system due to material re-evaporation and Ostwald ripening describes the theoretically predicted and experimentally obtained results. Thus, dewetting phenomena of thin metal layers can be used to manufacture nanostructured devices. From this point of view, the application of gold droplets as catalysts to

• highly functional intermediate products for further processing [3][4]. The presence of droplets and dewetting phenomena are not only observed in aqueous and organic systems, but also in inorganic systems, such as liquid metals [5] and ultrathin layers [6]. The formation of metallic nanodroplets can be

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

• ] since the signal from the interface was visible even when a nominal coverages corresponding to several layers was deposited. Stranski–Krastanov growth has been suggested for F4PEN on Cu(111) [63], and furthermore was supported by thickness-dependent XPS, where the relative intensity barely changed as

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

• We present both theoretical and experimental investigations of the proximity effect in a stack-like superconductor/ferromagnetic (S/F) superlattice, where ferromagnetic layers with different thicknesses and coercive fields are made of Co. Calculations based on the Usadel equations allow us to find

• 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

• multilayer. We observe that the resistive transition of the multilayer structure has multiple steps, which we attribute to the transition of individual superconductive layers with the critical temperature, Tc, depending on the local magnetization orientation of the neighboring F-layers. We argue that such

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

• ][23][24] are known to influence network formation at the solution–solid interface. One of the unconventional ways to influence the structure formation at the solution–solid interface involves the use of buffer layers. Such buffer layers typically comprise of monolayers formed by long chain alkanes [25

• of another layer in between the assembling building block and the substrate would allow the formation of an alternative polymorph that would not be obtained otherwise. In line with this strategy, self-assembled buffer layers of n-pentacontane (n-C50) have been used to obtain a previously unknown

• polymorph of hexakis(n-dodecyl)-peri-hexabenzocoronene (HBC-C12) which was not formed when the assembly process was carried out at the n-tetradecane–HOPG interface without the buffer layer [26]. Buffer layers of n-C50 have also been used to ‘select’ certain polymorphs of a Fréchet dendron based on the

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

• organized and dynamic layers were formed on HOPG (not shown). When, however, 1-phenyloctane, a broadly applied aromatic solvent in liquid-STM studies, was used, it was impossible to image the surface or adsorbed molecules regardless of the used surface, due to the occurrence of a large additional increase

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

• controlled via the manipulation of the magnetic order in the F subsystem [21][22][23][24][25][26]. One possible way to exert such a control is via interaction of superconductivity and interlayer exchange coupling (IEC) of F layers through a normal metal (NM) spacer. The IEC in a F/N/F system can be tuned by

• varying the thickness of the N spacer to organize antiparallel (AP), parallel (P) or non-collinearly aligned F layers [27]. Also, the presence of superconducting correlations in the same F/N/F system would favor AP alignment for singlet pairing or a NC configuration to generate a long-range triplet

• interaction between superconductivity and IEC is the Fe/Nb system. Proximity effects in Fe/Nb systems were extensively studied before [32][33][34][35][36]. The antiferromagnetic coupling of Fe layers through a Nb(y) spacer with y = (1.3 + 0.9 × n) nm (n = 0, 1, 2) was found in [37][38] by means of PNR. In the