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

• excited electron from the LUMO into unoccupied metallic states and/or a filling of the HOMO by an electron from the metal. We note that the HOMO and LUMO for the chemisorbed molecule differ from those of the gas phase molecule. Thus, the LUMO that is drawn in Figure 1a is not identical to the LUMO in the

• gas phase. For a second molecular layer, even without significant overlap of the wave functions of metal and molecule, quenching is also possible, because the CT may occur from the second layer to the metal via states in the first layer [5]. In principle, the hybridization of molecular and metallic

• differential energies of the PTCDA orbitals remain unaltered in comparison to those of PTCDA in the gas phase, which points to a more physisorptive bonding to the hBN/Cu(111) surface [32]. The HOMO of PTCDA is found at ca. 2.6 eV [32]. Hence, we can expect that both the LUMO and the HOMO are placed within the

PTCDA adsorption on CaF₂ thin films

• Philipp Rahe

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

• view of the optimum adsorption geometry, including isosurfaces at ±0.01 e/Å3 of the electron density difference Δρ = ρfull − ρslab − ρPTCDA. This difference was calculated as a difference between the electron densities of the full (ρfull), CaF2 slab (ρslab), and PTCDA gas phase (ρPTCDA) systems. The

• well as the three lowest unoccupied molecular orbitals (LUMO, LUMO+1, and LUMO+2) as calculated with cp2k for the PTCDA/CaF2(111) system are depicted in Figure 4e–h. The orbital shapes largely resemble earlier calculations of a flat PTCDA molecule in the gas phase [10], although the LUMO+1 and LUMO+2

• states are here separated by about 0.1 eV and found in different order (in agreement with a previous study [10], a smaller LUMO+1/LUMO+2 energetic separation was calculated for the gas-phase molecule). The dominant contribution of the orbitals to the data shown in Figure 2 is deferred from the orbital

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

• superstructure with respect to the quasi-hexagonal structure of the CoO 2BL film (red rectangle in Figure 6b). Arranging 2 in its gas phase configuration within this cell, we find that the CN groups of the dipolar bond have a distance of 0.4 nm and that the hydrogen bond has a length of 0.3 nm between the N atom

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

• to 5A, 6P is geometrically more flexible, more specifically, it is nonplanar in the gas phase and has a relatively low electron affinity. On the pristine Ag(100) substrate, 6P simply physisorbs with no evidence of LUMO hybridization, which remains unoccupied [21]. It will be shown that the

• . In the gas phase, 6P naturally occurs with a torsional angle of 35° between its phenyl rings [26]. The observation of such a twist on MgO(100)/Ag(100) suggests that the interaction between the 6P molecules and MgO is very weak. In addition, next to the 6P molecules with a zig-zag appearance, there

• overlap between the phenyl rings. This will cause an increase in the energy spread of the π bands, resulting in a decrease in the ionization potential and an increase in the electron affinity. Gas phase DFT calculations show that the EA of planar 6P (1.74 eV) is indeed 0.3 eV higher than the EA of twisted

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

• 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

• , elongated protrusion, four additional lobes contributed to the X-shaped appearance of the molecular units of 1. Each of these peripheral protrusions was attributed to one pyridin-4-ylethynyl substituent. Atomistic models (see overlays in Figure 2b), reflecting the gas-phase optimized molecular structure

• . Furthermore, the agreement between the gas-phase calculations and STM data indicated that no charging occurred upon pyrene adsorption on hBN/Cu(111) [37]. To complement the on-surface investigations, we measured the optical gap by means of UV–vis spectroscopic characterization in solution (toluene) of the

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

• ferrocene, the rotational barrier between these conformers amounts to only 0.04 eV in the gas phase [11][12][13], while for substituted ferrocenes the energy barrier values determined in the gas phase amount up to 0.2 eV [14][15][16]. In solution, barrier values of up to 0.7 eV are measured [17][18] and for

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

• the growth of the Pt-NPs does not occur in the gas phase but on the surface of the CNWs since nanoparticle growth in the gas phase should result in smaller particle sizes at high gas velocities (thus shorter residence time of the NP in the plasma), which is not the case here. Besides, the degree of

• precursor dissociation and hence the platinum concentration in the gas phase is expected to decrease with increasing gas velocities, as was previously demonstrated [17]. Electrochemically active surface area and long-term stability Even though the influence of the physicochemical properties of Pt/C on its

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

• ripening requires the existence of a medium where the material can be transported. Since there is no wetting layer (according to the WA and EA models, Figure 1), the Laplace pressure cannot be relieved by Ostwald ripening. Nevertheless, an Ostwald ripening process could also take place through the gas

• phase, although this process is kinetically inhibited. The re-evaporation process leads to a decrease in the number of droplets per area, while the droplet diameter values remain constant and the diameter distribution remains Gaussian, and no LSW distribution occurs as in Ostwald ripening processes [25

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

• ][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

• signs for PEN and PFP [11]. Electrostatic potential maps of PEN, F4PEN and PFP in the gas phase can be found in [46]. In general, hydrogen atoms bear a minimum, and fluorine atoms a maximum of the electron density, i.e., the quadrupole moments of F4PEN along the molecular short and long axes have

3D superconducting hollow nanowires with tailored diameters grown by focused He⁺ beam direct writing

• Rosa Córdoba,
• Alfonso Ibarra,
• Dominique Mailly,
• Isabel Guillamón,
• Hermann Suderow and
• José María De Teresa

Beilstein J. Nanotechnol. 2020, 11, 1198–1206, doi:10.3762/bjnano.11.104

• advantage of its small beam diameter (approx. 0.3 nm) and low proximity effect [28]. When precursor molecules from the gas phase are adsorbed on a substrate surface, He+ FIB dissociates them into non-volatile and volatile products. The non-volatile products attach to the surface, resulting in a deposit

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

• surfaces was motivated as follows. C42H28 is a polycyclic aromatic hydrocarbon (Figure 1a) with an extended system of delocalized π electrons. In the gas phase, intramolecular steric hindrance [11][12] causes the phenyl groups to rotate around their σ bonds, out of the tetracene backbone plane (Figure 1b

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

• electronic functionality of such nanometer-scale building blocks. A rational and well-established synthesis strategy for the creation of complex silicon nanostructures is metal-catalyzed vapor–liquid–solid (VLS) nanowire growth [13]. VLS nanowire growth belongs to the gas-phase synthesis procedures, similar

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

• 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

• compared to the elliptical shape in Figure 5c. For the identification of molecular orbitals, it is often sufficient to compare the dI/dV maps with the shape of the gas-phase molecular orbitals. Using this method, the U-shaped features have previously been associated to the LUMO of TCNQ [5][23][49]. Here

• , we corroborate this assignment by simulating constant-height dI/dV maps of a free, flat-lying molecule. We first calculated the gas-phase electronic structure using density functional theory (DFT) calculations with the B3PW91 functional and the 6-31g(d,p) basis set as implemented in the Gaussian 09

Gas-sensing features of nanostructured tellurium thin films

• Dumitru Tsiulyanu

Beilstein J. Nanotechnol. 2020, 11, 1010–1018, doi:10.3762/bjnano.11.85

• , nanotubes or nanowires from the gas phase under vacuum or argon atmosphere. On the other hand, nanostructuring can be performed mechanically as indicated by the possibility of growth of nanocrystalline gas sensors via rf sputtering (13.6 MHz) of Te in an ultra-high-purity argon atmosphere [24]. The main

Transition from freestanding SnO₂ nanowires to laterally aligned nanowires with a simulation-based experimental design

• Jasmin-Clara Bürger,
• Sebastian Gutsch and
• Margit Zacharias

Beilstein J. Nanotechnol. 2020, 11, 843–853, doi:10.3762/bjnano.11.69

• sites are changed. Furthermore, it should be considered that the gaseous Sn atoms might already partially react with oxygen in the gas phase and that parts of the graphite, which are not used in the reaction with the SnO2 powder, might react with a fraction of the gaseous oxygen. An effect of these

Adsorption behavior of tin phthalocyanine onto the (110) face of rutile TiO₂

• Lukasz Bodek,
• Mads Engelund,
• Aleksandra Cebrat and
• Bartosz Such

Beilstein J. Nanotechnol. 2020, 11, 821–828, doi:10.3762/bjnano.11.67

• presented in Figure 3d. An analogous combination of LT-STM image, DFT-simulated image and optimized geometry for a Sn-up molecule is presented in Figure 3e–g. A DFT-simulated image of a Sn-up molecule in the gas-phase geometry corresponds well to the experimental results. The bright protrusion centered

• strongly deformed on the surface. In contrast, simulated images of gas-phase SnPc in the Sn-down position do not recreate the experimental results (marked by the blue square in Figure S3, Supporting Information File 1). Especially, the pyrrole-like subunits appear much brighter than observed in the

• nonplanar Pc molecule. As a result, the abovementioned relaxation of a Sn-down Pc molecule leads to an increase in the dipole moment from −0.6 D for gas-phase SnPc to −1.13 D for relaxed SnPc. This effect is mainly due to a change of the position of positively charged H atoms at the periphery of the

Adsorptive removal of bulky dye molecules from water with mesoporous polyaniline-derived carbon

• Hyung Jun An,
• Jong Min Park,
• Nazmul Abedin Khan and
• Sung Hwa Jhung

Beilstein J. Nanotechnol. 2020, 11, 597–605, doi:10.3762/bjnano.11.47

• -presence of activating agents such as KOH, H3PO4 or ZnCl2 [39]. Even though PANI-derived carbon (PDC) was used in gas-phase adsorption [40][41], it has been scarcely applied in liquid phase adsorption. Only recently we applied PDC for the possible purification of water contaminated with organics and fuel

Interfacial charge transfer processes in 2D and 3D semiconducting hybrid perovskites: azobenzene as photoswitchable ligand

• Nicole Fillafer,
• Tobias Seewald,
• Lukas Schmidt-Mende and
• Sebastian Polarz

Beilstein J. Nanotechnol. 2020, 11, 466–479, doi:10.3762/bjnano.11.38

• system of a semiconductor. Torres et al. reported calculations of a charge-transfer complex of para-methyl red/TiO2 in the gas phase where the isomerisation is fully quenched. The photoexcited state is oxidized immediately through a charge transfer from the azobenzene to TiO2 and no conformational change

DFT calculations of the structure and stability of copper clusters on MoS₂

• Cara-Lena Nies and
• Michael Nolan

Beilstein J. Nanotechnol. 2020, 11, 391–406, doi:10.3762/bjnano.11.30

• ) adsorbed on MoS2. The energy of a single gas phase Cu atom (ECu_atom) is multiplied by n, the number of Cu atoms in adsorbed Cun. 2. Binding energy with reference to a free Cun cluster: where ECu_cluster is the energy of the most favourable Cun nanocluster structure in vacuum. For two atoms, this is a Cu2

• positive binding energy when calculated with Equation 2, indicating that they are unstable. However, this is most likely due to the most favourable gas phase three-atom cluster having a different structure from that taken upon adsorption on the MoS2 ML. When calculating the stability using adsorbed Cu3

Formation of metal/semiconductor Cu–Si composite nanostructures

• Natalya V. Yumozhapova,
• Andrey V. Nomoev,
• Vyacheslav V. Syzrantsev and
• Erzhena C. Khartaeva

Beilstein J. Nanotechnol. 2019, 10, 2497–2504, doi:10.3762/bjnano.10.240

• content of 50 atom %. Additionally, an estimation of the effective experimental cooling rate was made. Keywords: composite nanoparticle; gas-phase synthesis; molecular dynamics modelling; Introduction In recent years, due to the development of various methods of synthesis, it has become possible to

• they are immiscible in the bulk state. In addition to chemical techniques [9][10][11][12], physical methods such as gas-phase methods [5][6][15], laser ablation [7][8][16], and magnetron-sputter gas-phase condensation [17] have been developed. When these methods are combined with the possibility of

Microbubbles decorated with dendronized magnetic nanoparticles for biomedical imaging: effective stabilization via fluorous interactions

• Da Shi,
• Justine Wallyn,
• Dinh-Vu Nguyen,
• Francis Perton,
• Delphine Felder-Flesch,
• Sylvie Bégin-Colin,
• Mounir Maaloum and
• Marie Pierre Krafft

Beilstein J. Nanotechnol. 2019, 10, 2103–2115, doi:10.3762/bjnano.10.205

• before being flushed above the aqueous phase into the sealed glass vial during 3 min in order to saturate the gas phase with F-hexane. The resulting dispersions were treated using a VialMix shaker (Bristol-Myers Squibb, New York, NY) for 45 s under F-hexane-saturated N2 at room temperature. The resulting

Review of advanced sensor devices employing nanoarchitectonics concepts

• Katsuhiko Ariga,
• Tatsuyuki Makita,
• Masato Ito,
• Taizo Mori,
• Shun Watanabe and
• Jun Takeya

Beilstein J. Nanotechnol. 2019, 10, 2014–2030, doi:10.3762/bjnano.10.198

• . Sensors for chemical substances Mainly due to the high demand to solve environmental problems, vapor sensors and gas-phase chemical sensors have been actively researched. Tang and co-workers accomplished drastic improvement of sensitivity of H2S gas detection by mechanical deformation of ultrathin single

Long-term entrapment and temperature-controlled-release of SF₆ gas in metal–organic frameworks (MOFs)

• Hana Bunzen,
• Andreas Kalytta-Mewes,
• Leo van Wüllen and
• Dirk Volkmer

Beilstein J. Nanotechnol. 2019, 10, 1851–1859, doi:10.3762/bjnano.10.180

• ). To a solid sample (20 mg), 1 mL of concentrated sulfuric acid (95–98 wt %) was added and the gas phase was analyzed by the mass spectrometer. Powder XRD data were collected in the 5–50° 2θ range using a Seifert XRD 3003 TT powder diffractometer with a Meteor1D detector operating at room temperature

• (determined by TGA; see Figure S11 in Supporting Information File 1). Furthermore, we studied the possibility to release SF6 from the pores of MFU-4 by decomposing the framework. To do so, we treated a sample of the MOF loaded with SF6 with an acid, namely concentrated sulfuric acid, and analyzed the gas

• phase by mass spectrometry (Figure S12 in Supporting Information File 1). As expected, upon adding the acid to the reaction vessel, the framework decomposed and an immediate evolution of gas bubbles was observed. The SF6 release could be followed by mass spectrometry; however, a precise quantification

High-temperature resistive gas sensors based on ZnO/SiC nanocomposites

• Vadim B. Platonov,
• Marina N. Rumyantseva,
• Alexander S. Frolov,
• Alexey D. Yapryntsev and
• Alexander M. Gaskov

Beilstein J. Nanotechnol. 2019, 10, 1537–1547, doi:10.3762/bjnano.10.151

• sensor properties of the synthesized materials were investigated by in situ conductivity measurements. Figure 8 shows the change in the resistance of ZnO nanofibers and ZnO/SiC nanocomposites with a periodic change in the composition of the gas phase in the presence of NH3 (Figure 8a,b) and CO (Figure 8c

• semiconductor materials: where CO(gas), NH3(gas) are molecules of carbon monoxide and ammonia in the gas phase, is a particle of chemisorbed oxygen, e− is an electron released into the conduction band; CO2(gas), N2(gas), H2O(gas) are the molecules of the reaction products desorbed from the surface of the

• material to the gas phase. The data obtained allowed us to calculate the value of the sensor response as where Rair is the resistance of the material in background air, and Rgas is the resistance of the material in the presence of the target gas (СО or NH3). The temperature dependence of the sensor

Growth of lithium hydride thin films from solutions: Towards solution atomic layer deposition of lithiated films

• Ivan Kundrata,
• Karol Fröhlich,
• Lubomír Vančo,
• Matej Mičušík and
• Julien Bachmann

Beilstein J. Nanotechnol. 2019, 10, 1443–1451, doi:10.3762/bjnano.10.142

• filters for hazardous byproducts, since the liquid waste from the deposition process can be easily caught, neutralized, and the solvent can be recovered by distillation. sALD opens up the possibility to use n-butyllithium, which does not exist in the gas phase, as a precursor for lithiated films [13

• ]. Furthermore, such organolithium precursors in solution are inexpensive and easier to handle, more so than the required volatility of precursors for standard ALD would allow [7]. Because precursors that cannot be used in ALD are used in sALD, reactions that are impossible in the gas phase can be explored, even