Interface interaction of transition metal phthalocyanines with strontium titanate (100)

• Reimer Karstens,
• Thomas Chassé and
• Heiko Peisert

Beilstein J. Nanotechnol. 2021, 12, 485–496, doi:10.3762/bjnano.12.39

• transfer with the oxide substrate was observed, involving both the macrocycle and the central metal atom. For molecules of the first monolayer, an electron transfer to the central metal atom is concluded from transition metal 2p core level photoemission spectra. The number of interacting molecules in the

• first monolayer on the oxide surface depends on the central metal atom of the phthalocyanine, whereas the substrate preparation has minor influence on the interaction between CoPc and SrTiO3(100). Differences of the interaction mechanism to related TiO2 surfaces are discussed. Keywords: charge transfer

• in a predominantly SrO-terminated, but mixed crystal surface. In order to modify the surface preparation, another procedure, called “preparation II”, was applied. After a wet chemical preparation, a monolayer of TiO2 was grown epitaxially on top of the STO surface by evaporation of Ti (0.6 Å) in an

Reconstruction of a 2D layer of KBr on Ir(111) and electromechanical alteration by graphene

• Zhao Liu,
• Antoine Hinaut,
• Stefan Peeters,
• Sebastian Scherb,
• Ernst Meyer,
• Maria Clelia Righi and
• Thilo Glatzel

Beilstein J. Nanotechnol. 2021, 12, 432–439, doi:10.3762/bjnano.12.35

• pattern. Comprehensive calculations by DFT, taking into account the observed periodicities, resulted in a new low-energy reconstruction. However, it is fully relaxed into a common cubic structure when a monolayer of graphene is located between substrate and KBr. By using Kelvin probe force microscopy, the

• hexagonal boron nitride (h-BN), which cannot only be used as a functional insulating monolayer [8][9][10], but can also be stacked with graphene layers [11][12] and has, among other interesting properties, a very stable structural superlubricity [7]. Besides the stacking of different monolayers, the

• to the expected cubic configuration of bulk KBr and the work function of the system is strongly altered. Results and Discussion The thermal deposition of less than a monolayer of KBr on an atomically clean Ir(111) surface under ultrahigh vacuum (UHV) conditions results in the formation of islands on

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

• knock-out. Typically, ion beam machining is carried out under high-vacuum conditions, where the amount of contaminants in the chamber (mostly water, but also hydrocarbons) still can form a monolayer per second on average. Often, additional contaminants may be present on the sample surface, for example

• features in the single-digit nanometer range where small sputter rates play a minor role. This holds true not only for monolayer 2D materials, such as graphene, but also for thin films forming quasi 2D geometries. The versatility of the corresponding materials opens a wide field of exciting applications

Extended iron phthalocyanine islands self-assembled on a Ge(001):H surface

• Rafal Zuzak,
• Marek Szymonski and
• Szymon Godlewski

Beilstein J. Nanotechnol. 2021, 12, 232–241, doi:10.3762/bjnano.12.19

• ) phthalocyanine (FePc) molecules on a Ge(001):H surface results in monolayer islands extending over hundreds of nanometers and comprising upright-oriented entities. Scanning tunneling spectroscopy reveals a transport gap of 2.70 eV in agreement with other reports regarding isolated FePc molecules. Detailed

• molecular wetting layers [15] and two-dimensional materials, such as graphene [16][17], hBN [11][18], or even organic layers [19]. Recently, it has been proposed that a monolayer of transition metal dichalcogenides, for example, MoS2, may play a similar role [4][20][21]. Similarly, it has been reported that

• mentioning that the observed structure does not correspond to any known FePc crystal phase. This indicates the influence of the substrate–molecule interactions on the crystal formation in the monolayer. The bulk α-FePc phase is characterized by columns within which the separation between the centers of the

Scanning transmission helium ion microscopy on carbon nanomembranes

• Daniel Emmrich,
• Annalena Wolff,
• Nikolaus Meyerbröker,
• Jörg K. N. Lindner,
• André Beyer and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2021, 12, 222–231, doi:10.3762/bjnano.12.18

• program Stopping and Range of Ions in Matter (SRIM) was used for Monte Carlo simulations [26]. When simulating thin membranes, it is important to use the monolayer collisions calculation type. Otherwise inaccurate results could be obtained as the collisions will be averaged over the mean free path. The

• using the software package TRIM in the program Stopping and Range of Ions in Matter (SRIM) [26]. The “Surface Sputtering/Monolayer Collision Steps” calculation was selected due to the limited thickness of the membranes to ensure that the collisions in each monolayer were considered. 50000 ions at 15 and

TiO_x/Pt₃Ti(111) surface-directed formation of electronically responsive supramolecular assemblies of tungsten oxide clusters

• Marco Moors,
• Yun An,
• Agnieszka Kuc and
• Kirill Yu. Monakhov

Beilstein J. Nanotechnol. 2021, 12, 203–212, doi:10.3762/bjnano.12.16

• monolayer/s. The deposition rate was obtained by previously performed calibration measurements using a quartz microbalance, which was positioned in the same direction and distance toward the evaporation source as the sample in order to obtain comparable results. The surface coverages shown herein represent

• ’-TiOx phase with a marked unit cell. The dark areas inside the trenches represent holes in the oxide film. (c) The z’-TiOx phase after deposition of W3O9 (≈0.1 monolayer coverage; 40 × 40 nm; UB = 1.00 V; IT = 86 pA). The clusters are always aligned along the trenches. (d) A submolecular resolution scan

• ; IT = 100 pA) of the w’-TiOx phase with a marked unit cell. The bright spots represent the coincidence points in the moiré structure caused by the interplay between the oxide layer and the substrate. (c) The w’-TiOx phase after deposition of W3O9 (≈0.6 monolayer coverage; 50 × 50 nm; UB = 1.57 V; IT

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

• electron irradiation-induced cross-linking of a self-assembled monolayer (SAM) of 4′-nitro-1,1′-biphenyl-4-thiol (NBPT) and second, purple membrane (PM) containing genetically modified bacteriorhodopsin (BR) carrying a C-terminal His-tag. The NBPT-CNM was further modified to carry nitrilotriacetic acid

• (NTA) terminal groups for the interaction with the His-tagged PMs forming a quasi-monolayer of His-tagged PM on top of the CNM-NTA. The formation of the Ni-NTA/His-tag complex leads to the unidirectional orientation of PM on the CNM substrate. Electrophoretic sedimentation was employed to optimize the

• -standing, large-area PM monolayer remains challenging. Previous approaches for the oriented assembly of PM were based on solid supports [8][29][30] or interfaces between liquids [31][32]. Other approaches, by implementing transmembrane proteins such as BR in lipid bilayers, have so far been used only to

ZnO and MXenes as electrode materials for supercapacitor devices

• Ameen Uddin Ammar,
• Ipek Deniz Yildirim,
• Feray Bakan and
• Emre Erdem

Beilstein J. Nanotechnol. 2021, 12, 49–57, doi:10.3762/bjnano.12.4

• of N-CuMe2Pc nanorods. The sample M10P2, in which 10 mg of MXene and 2 mg N-CuMe2Pc were used, exhibited high ionic conductivity and the measured value of the specific capacitance was 786 F·g−1 [16]. Li et al. synthesized monolayer wrinkled Ti3C2Tx grafted with HF and decorated with N-doped carbon by

Nanomechanics of few-layer materials: do individual layers slide upon folding?

• Ronaldo J. C. Batista,
• Rafael F. Dias,
• Ana P. M. Barboza,
• Alan B. de Oliveira,
• Taise M. Manhabosco,
• Thiago R. Gomes-Silva,
• Matheus J. S. Matos,
• Andreij C. Gadelha,
• Cassiano Rabelo,
• Luiz G. L. Cançado,
• Ado Jorio,
• Hélio Chacham and
• Bernardo R. A. Neves

Beilstein J. Nanotechnol. 2020, 11, 1801–1808, doi:10.3762/bjnano.11.162

• been obtained through radial deformations [32], lattice dynamics studies [33], deformations of suspended layers [2][6], and bubble profiles [12]. The values reported for the bending stiffness of a graphene monolayer vary from 0.8 to 10,000 eV [34]. Also, there is no consensus on how κ varies with the

• . The measured values of thickness h, from 1.2 to 30.0 nm, indicate that the measured folds involve materials from monolayer talc to approx. 30-layer talc. The corresponding values of the radius R0 range from 2.15 to 162 nm, that is, an increase of two orders of magnitude. The figure also shows a fitted

• geometries for folded edges in a graphene monolayer (Figure 2a) and in three-layered graphene (Figure 2b), obtained through MD simulations (details about MD simulations are found in Supporting Information File 1). As can be seen in Figure 2a, the model geometry consists of a sequence of straight lines and

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

• ) for helium (13 fold) but only from 6 nm (milling) to 4 nm (imaging) for lithium (1.5 fold). The simulated minimum milling width of a 30 keV point-like ion beam in Figure 4 has been obtained using SRIM [39]. The “monolayer collision steps/surface sputtering” mode has been used to simulate the size of

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

• 18,150 and 18,450 cm−1 can be detected, already from the first monolayer onward. In contrast, FL from PTCDA on a bare Cu(111) surface is present only from the second PTCDA layer onward. Hence, a single layer of hBN decouples PTCDA from the metal substrate to an extent that a weak radiative FL decay of

• to which extent decoupling of the organic molecules from a metal electrode is achieved when a 2DM layer in the limit of a single interfacial layer, for example, a monolayer of hexagonal boron nitride (hBN), is used. Such a decoupling is achieved when the wave functions of the metal are spatially

• molecule from a metal substrate by a monolayer of hBN we chose PTCDA and the Cu(111) surface. PTCDA serves as a planar model molecule for investigations of organic layers on surfaces [20][21][22][23]. Monolayers of hBN on Cu(111) have been investigated by several groups and are, hence, rather well

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

• monolayer formation and hybrid interfaces. In the following sections, we first introduce our computational methods for adsorbate structure identification with BOSS, the first-principles calculations, and their application on detecting the stable adsorbates of camphor on Cu(111). We then present our results

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

• photoemission tomography (PT) have enabled the quantification of both the charge on individual molecules and the number of charged molecules in the 5A monolayer (ML) [14]. For 5A MLs on regularly grown epitaxial MgO(100) films, all molecules appear to be charged. Orbital-resolved STM reveals the LUMO both above

• pinning regime” has been realized by the proportion of charged and neutral molecules coexisting in the first monolayer, as schematically illustrated in Figure 1. In this work function regime, ranging from all the molecules being charged to no molecules being charged, the molecular ML is characterized by a

• physical coupling to the substrate induced by the charge transfer. Finally, the charging effect on the thermal dynamics and the stability of the 6P monolayer are considered. Results and Discussion Ambivalent behavior of 6P on regularly prepared MgO(100)/Ag(100) thin films Figure 2 shows STM images of four

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

• findings in the monolayer regime on Ag(111). Accordingly, as for the trans-like pyrene 2, the support played a minor role in the intralayer structure of the extended molecular arrays. Nonetheless, the results for the pyrenes 1–3 on hBN/Cu(111) clearly demonstrated that the support did affect the rotational

• was cleaned by repeated Ar+ sputtering cycles at an energy of 800–1000 eV, followed by annealing at 1070 K. Monolayer hBN was grown via chemical vapor deposition using borazine ((HBNH)3, Katchem spol s.r.o, www.katchem.cz), following a protocol described previously [25]. Subsequently, a submonolayer

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

• presented synthesis method). A Pt wire was used as the counter electrode, and Hg/HgSO4 (sat. K2SO4) from Radiometer Analytical with an electrode potential of 680 mV vs NHE (measured by us) was used as the reference electrode. The ECSA was calculated based on the Hads peaks and a hydrogen monolayer

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

• values below the abscissa and converges towards zero. This is a major distinction since values above zero leads to the formation of a continuous thin film, whereas values below zero promote the formation of droplets on the surface. Since a gold monolayer has a nominal thickness of 0.32 nm, the maximum

• thickness of 0.38 nm, predicted in the vW model at 550 °C, exceeds the monolayer thickness and a second gold monolayer starts to form. Consequently, this model predicts the growth of a layer of gold on silicon oxide. In contrast to the vW model, the other two models predict droplet formation over the entire

• same behaviour: Gold forms droplets on silicon with a wetting layer between the droplets. The thickness of the wetting layer is approx. 0.28 ± 0.02 nm, at room temperature, and approx. 0.34 ± 0.08 nm at 550 °C, since the zero-crossing of the graphs occurs at these values. Assuming that a gold monolayer

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

• . The F4PEN monolayer was essentially lying on Ag(111), and multilayers adopted π-stacking. Our study shed light not only on the F4PEN–Ag(111) interface but also on the fundamental adsorption behavior of fluorinated pentacene derivatives on metals in the context of interface energetics and growth mode

• intermediate case. We determined the vertical adsorption heights of F4PEN (sub)monolayers on Ag(111) employing the XSW technique [64][65][66][67]. The lateral order in the monolayer was determined by LEED. Possible chemical interactions between F4PEN and the substrate were studied by XPS. The energy level

• integer. The coherent fraction 0 ≤ fH ≤ 1 describes the degree of vertical order of the adsorbate atoms, with fH = 0 for a completely disordered system and fH = 1 for all probed adsorbate atoms having the same adsorption distance. XSW measurements were performed for two (sub)monolayer coverages of F4PEN

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

• study of the electrical performance of chemically synthesized monolayer molybdenum disulfide (MoS2) field-effect transistors irradiated with a focused helium ion beam as a function of increasing areal irradiation coverage. We determine an optimal coverage range of approx. 10%, which allows for the

• 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

• exploration of nanometer-scale structural modifications of TMD devices [6][7][8]. The localized formation of defects by focused ion beam irradiation has been shown to induce unusual electronic properties in monolayer TMDs, such as pseudo-metallic phase transitions in MoS2 and WSe2 [9][10], resistive switching

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

• solution–solid interface. One of the ways to influence network formation at this interface is to physically decouple the self-assembled monolayer from the underlying substrate thereby removing the influence of the substrate lattice, if any. Here we show a systematic exploration of self-assembly of a

• structure in which the alkane molecules are fully extended and are oriented at 90° with respect to the lamella axis. This monolayer structure is identical to that reported earlier [26]. After thoroughly understanding and optimization of the self-assembly behavior of BA-OC14 and n-C50 at the 1-phenyloctane

• when carried out using premixed solutions of the two components. Typically, a drop of 1 × 10−5 M solution of n-C50 was first applied onto a freshly cleaved HOPG surface and the surface was imaged using STM to ensure full coverage of the n-C50 monolayer. After this, a drop of BA-OC14 solution was

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

• were performed in constant-current mode using an Omicron Scala SPM controller. All experiments were performed in the thermostatted environment (21.5 ± 0.5 °C) of the NanoLab Nijmegen. (a) Molecular structure of MnTUPCl. (b) Molecular structure of MnTUPOAc. (c) STM images of a monolayer of MnTUPCl at a

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

• the DBP molecules are well decoupled from the Ni(111) surface. Furthermore, a highly ordered DBP monolayer is obtained on h-BN/Ni(111) by depositing the molecules at a substrate temperature of 170 °C. The structural results are obtained by quantitative low-energy electron diffraction and low

• 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 h-BN/Cu(111) were found recently [11][12]. This raises the question under which specific conditions an h-BN monolayer is sufficient to efficiently decouple organic molecules. Until now only a few publications exist which are concerned with this issue [13][14][15][16]. In this work we report on the

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

• (Figure 1c) where one diagonal pair of phenyl groups would appear higher than the other. Such a configuration was indeed observed for a closed monolayer of C42H28 on Ag(100) [24]. However, it is difficult to infer geometric heights from STM images due to variations in the local density of states. Moreover

• similar superstructure with planar C42H28 backbones oriented parallel to the Au(111) surface was reported. In that work a multilayer C42H28 film was deposited at room temperature and subsequently annealed to achieve a monolayer coverage. Different superstructures of C42H28 with twisted and tilted

Monolayers of MoS₂ on Ag(111) as decoupling layers for organic molecules: resolution of electronic and vibronic states of TCNQ

• Asieh Yousofnejad,
• Gaël Reecht,
• Nils Krane,
• Christian Lotze and
• Katharina J. Franke

Beilstein J. Nanotechnol. 2020, 11, 1062–1071, doi:10.3762/bjnano.11.91

• of decoupling layers made use of the in situ fabrication of single layers of transition metal dichalcogenides on metal surfaces. A monolayer of MoS2 on Au(111) provided very narrow molecular resonances, close to the thermal resolution limit at 4.6 K [26]. The exquisite decoupling efficiency has been

• properties of MoS2 on a metal surface are not the same as those of a free-standing monolayer. Both theory and experiment have found considerable hybridization of electronic states at the interface [29]. As a consequence, the bandgap is narrowed. Instead of the predicted bandgap of 2.8 eV of the free-standing

• vibronic states of the gas-phase molecule. Results and Discussion We have grown monolayer islands of MoS2 on an atomically clean Ag(111) surface, which had been exposed to sputtering–annealing cycles under ultrahigh vacuum before. The growth procedure was adapted from that of MoS2 on Au(111) [34][35], with

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

• spot, which we assume to be a single monolayer of MBA fully covering the surface [38][41]. From the SERS and Raman spectra of Figure 5 the EF values were calculated (Table 3). The sample that gave the most homogeneous EF through over the investigated wavelength range was TiO2/Au 6 nm deposited at 12 Pa

Key for crossing the BBB with nanoparticles: the rational design

• Sonia M. Lombardo,
• Marc Schneider,
• Akif E. Türeli and
• Nazende Günday Türeli

Beilstein J. Nanotechnol. 2020, 11, 866–883, doi:10.3762/bjnano.11.72

• brain endothelial cells) monolayer in vitro and exhibited a significantly higher accumulation in the brain than non-conjugated liposomes, showing the ability of this carrier system to cross the BBB. It was also shown that these particles could accumulate in the glioma cells and significantly increase