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

• structure of complex molecular adsorbates from microscopy images can be difficult, and using atomistic simulations to find the most stable structures is limited to partial exploration of the potential energy surface due to the high-dimensional phase space. In this study, we present the recently developed

• Bayesian Optimization Structure Search (BOSS) method as an efficient solution for identifying the structure of non-planar adsorbates. We apply BOSS with density-functional theory simulations to detect the stable adsorbate structures of (1S)-camphor on the Cu(111) surface. We identify the optimal structure

• among eight unique types of stable adsorbates, in which camphor chemisorbs via oxygen (global minimum) or physisorbs via hydrocarbons to the Cu(111) surface. This study demonstrates that new cross-disciplinary tools, such as BOSS, facilitate the description of complex surface structures and their

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

• underlying metal [2][3]. As dielectric films can significantly reduce the work function, principally due to Pauli repulsion (pushback) at the metal interface, adsorbates of sufficiently high electron affinity (EA) will become negatively charged via tunneling from the underlying metal. This was predicted by

• Pacchioni et al. [4][5][6] and either inferred or observed for adsorbates ranging from metal atoms [7][8] and small molecules [9][10] to larger π-conjugated molecules [11][12][13]. This phenomenon has been comprehensively analyzed for 5A on epitaxial MgO(100)/Ag(100), in which orbital-resolved STM and

• is only a small reduction of Φ, then the system is in the vacuum level alignment regime and there is no charge transfer. If there is any significant change in Φ, then the system is in the Fermi level pinning regime with equilibrium achieved by a balance between charged and neutral adsorbates in the

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

• , molecule–metal interactions can adversely affect the intrinsic electronic characteristics of molecular adsorbates and quench the optical properties [9][10][11][12][13]. Consequently, recent studies aiming to characterize the relation of adsorption, supramolecular organization, and electronic and optical

• allows the determination of the electronic properties of the pyrene adsorbates by STM and STS", and the comparison with the gaps estimated by theoretical simulations in vacuum and by UV-vis spectroscopies in solution. Remarkably, the electronic states of the pyrene adsorbates near the Fermi level, probed

• of well-defined, narrow molecular resonances and large HOMO–LUMO gaps evidenced a reduction of the electronic molecule–support interactions by the hBN spacer layer, as previously reported for adsorbates on hBN/Cu(111) [28][35][36][37][38] and other hBN/metal supports [18][19][20][79][80]. The dI/dV

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

• ). Prior to testing, the devices were outgassed at a pressure of approx. 10−5 mbar for 12 h to minimize surface adsorbates. Helium ion irradiations were carried out at a beam energy of 30 keV and He gas pressure of 2 × 10−6 Torr, using a Zeiss Nanofab microscope. The fabricated MoS2 FETs were placed in the

• than half of the channel has been treated with the ion beam. Thus, we expect a dominant contribution of oxygen-containing atmospheric adsorbates (known p-type dopants in MoS2) in saturating the vacancy sites created by the ion beam, allowing for residual hole conduction in the newly formed effective

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

• ) [18][19], while Au(111) is characterized by a surface-projected gap of sp-derived electron states [20]. Graphene on Pt(111) exhibits a considerable distance of 330 pm from the metal surface [21], which implies a weak graphene–metal hybridization. Adsorbates on graphene-covered Pt(111) are therefore

Quantitative determination of the interaction potential between two surfaces using frequency-modulated atomic force microscopy

• Nicholas Chan,
• Carrie Lin,
• Tevis Jacobs,
• Robert W. Carpick and
• Philip Egberts

Beilstein J. Nanotechnol. 2020, 11, 729–739, doi:10.3762/bjnano.11.60

• holder, transferred into the vacuum chamber, and baked at 120 °C for 1 h to remove any residual adsorbed moisture and other adsorbates on the probe. No tip preparation beyond this was conducted, to ensure that the tip structure remained as similar to the initial images and as small as possible. Before

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

• effective adsorption of small MO or MB since van der Waals interactions rely on adequate matching between pore and adsorbates. On the contrary, bulky dye molecules such as AR1 and JGB can interact effectively with KOH-900 via van der Waals interactions, which relies on the suitable pore size of KOH-900 for

Atomic-resolution imaging of rutile TiO₂(110)-(1 × 2) reconstructed surface by non-contact atomic force microscopy

• Daiki Katsube,
• Shoki Ojima,
• Eiichi Inami and
• Masayuki Abe

Beilstein J. Nanotechnol. 2020, 11, 443–449, doi:10.3762/bjnano.11.35

• -AFM and tunneling current for STM), the surface structure sometimes results in different contrasts in both images. In Figure 3, white squares and circles indicate line defects and protrusions, which are considered to be adsorbates or contamination. A line defect was imaged as a likely vacancy by STM

An advanced structural characterization of templated meso-macroporous carbon monoliths by small- and wide-angle scattering techniques

• Felix M. Badaczewski,
• Marc O. Loeh,
• Torben Pfaff,
• Dirk Wallacher,
• Daniel Clemens and
• Bernd M. Smarsly

Beilstein J. Nanotechnol. 2020, 11, 310–322, doi:10.3762/bjnano.11.23

• mesoporosity of these monolithic carbon materials was studied by the sorption behavior of a relatively large organic molecule (p-xylene) in comparison to typical gas adsorbates (Ar). In addition, to obtain a detailed view on the nanopore space small-angle neutron scattering (SANS) combined with in situ

• adsorbates such as nitrogen, argon, krypton or carbon monoxide. We chose p-xylene as an adsorbate for vapour sorption to address the sorption at room temperature. To obtain a detailed view of the nanopore space, which exhibits micro-, meso- and macropores, but with an upper limit of ca. 100 nm, small-angle

Kelvin probe force microscopy work function characterization of transition metal oxide crystals under ongoing reduction and oxidation

• Dominik Wrana,
• Karol Cieślik,
• Wojciech Belza,
• Christian Rodenbücher,
• Krzysztof Szot and
• Franciszek Krok

Beilstein J. Nanotechnol. 2019, 10, 1596–1607, doi:10.3762/bjnano.10.155

• known that water molecules present in the ambient air form a dipole layer, which can give rise to an effective surface potential [49]. To reduce the impact of weakly interacting adsorbates, in the next step, the sample underwent in situ UHV annealing, which implicated a WF decrease of both TiO and

• abundant adsorbates, also mimicking the typical operating temperatures of metal oxide gas sensors [51]. Numerical calculations suggest that H2O and CO2 species present in air saturate almost all free adsorption sites on TiO2-terminated SrTiO3(100) [52]. The low Redhead desorption temperature of H2O (CO2

• ) of 233–283 K (428–523 K) calculated by Baniecki et al. [52] suggests that our surface, which is predominantly TiO2-terminated, is cleaned of those adsorbates after annealing, hence the 0.35 eV difference in the WF. The lower response of TiO to annealing is a hint of the higher adsorption energy of

Imaging the surface potential at the steps on the rutile TiO₂(110) surface by Kelvin probe force microscopy

• Masato Miyazaki,
• Huan Fei Wen,
• Quanzhen Zhang,
• Yuuki Adachi,
• Jan Brndiar,
• Ivan Štich,
• Yan Jun Li and
• Yasuhiro Sugawara

Beilstein J. Nanotechnol. 2019, 10, 1228–1236, doi:10.3762/bjnano.10.122

• and steps are formed. In this image, the bright spots on the surface are adsorbed oxygen species or other adsorbates. The profiles of the average height show that the height of both and steps was about 260 pm, which is smaller than the known height of 325 pm because of the large tip–sample distance

In situ AFM visualization of Li–O₂ battery discharge products during redox cycling in an atmospherically controlled sample cell

• Kumar Virwani,
• Younes Ansari,
• Khanh Nguyen,
• Francisco José Alía Moreno-Ortiz,
• Jangwoo Kim,
• Maxwell J. Giammona,
• Ho-Cheol Kim and
• Young-Hye La

Beilstein J. Nanotechnol. 2019, 10, 930–940, doi:10.3762/bjnano.10.94

• deposition [3], corrosion and molecular adsorbates on a variety of surfaces [4] have also been investigated with scanning probe microscopy. In situ local probe techniques at electrical interfaces [5] use scanning probe microscopy to probe surface changes and reactions. A recent review by Yang et al. [6

The effect of translation on the binding energy for transition-metal porphyrines adsorbed on Ag(111) surface

• Luiza Buimaga-Iarinca and
• Cristian Morari

Beilstein J. Nanotechnol. 2019, 10, 706–717, doi:10.3762/bjnano.10.70

• DFT results can fail to accurately reproduce all these situations mainly because of the underestimation of correlation effects in DFT. Consequently, spin effects are described with limited accuracy for both TM and ligand spin. The latter is just barely present in the calculations of adsorbates [77

Intuitive human interface to a scanning tunnelling microscope: observation of parity oscillations for a single atomic chain

• Sumit Tewari,
• Jacob Bakermans,
• Christian Wagner,
• Federica Galli and
• Jan M. van Ruitenbeek

Beilstein J. Nanotechnol. 2019, 10, 337–348, doi:10.3762/bjnano.10.33

• valence electrons in metals [34]. It is possible to image the atomic configuration by functionalizing the STM tip by adsorbates (for example CO molecules [35] or other foreign adsorbates [36]) at the tip apex, and by quantum point contact microscopy [37]. To keep the surface clean we did not introduce

• adsorbates in the system and dragging the STM tip in contact with the surface is also not a useful option as the STM tip may pick up the adatoms we want to study later. So, we devised a simple geometric technique to get the information of the surface atom positions without the need to resolve the individual

• unwanted adsorbates that may be present in the UHV chamber, most likely hydrogen. In fact we have observed this jump to contact when approaching a Au adatom from the top in more than 80% of the times and we attribute it to the relaxation [42] of tip and surface atoms. Recent work [43][44], albeit not

Wet chemistry route for the decoration of carbon nanotubes with iron oxide nanoparticles for gas sensing

• Hussam M. Elnabawy,
• Juan Casanova-Chafer,
• Badawi Anis,
• Mostafa Fedawy,
• Mattia Scardamaglia,
• Carla Bittencourt,
• Ahmed S. G. Khalil,
• Eduard Llobet and
• Xavier Vilanova

Beilstein J. Nanotechnol. 2019, 10, 105–118, doi:10.3762/bjnano.10.10

• into more reactive species that, in turn, interact with CNTs. In addition, such nanoparticles shift the Fermi level of CNTs, adsorb target molecules, and help in mediating the charge transfer between adsorbates and CNTs [6][10]. Several metal oxides have been reported as useful for decorating CNTs and

Apparent tunneling barrier height and local work function of atomic arrays

• Neda Noei,
• Alexander Weismann and
• Richard Berndt

Beilstein J. Nanotechnol. 2018, 9, 3048–3052, doi:10.3762/bjnano.9.283

• . This is reflected by the notion of a local work function Φ [7][8][9]. Adsorbates modify Φ in an intriguing manner [10][11][12][13]. In turn, variations of Φ produce, e.g., atomic-scale contrast in field-emission microscopy, photo-emission electron microscopy, and low-energy electron microscopy [14][15

Investigation of CVD graphene as-grown on Cu foil using simultaneous scanning tunneling/atomic force microscopy

• Majid Fazeli Jadidi,
• Umut Kamber,
• Oğuzhan Gürlü and
• H. Özgür Özer

Beilstein J. Nanotechnol. 2018, 9, 2953–2959, doi:10.3762/bjnano.9.274

• conducting or semiconducting samples, because the acquired spectroscopies associated with forces and tunneling current between the foremost atoms of probe and sample provide complementary results. This would be helpful to detect distinct unique structures or chemical adsorbates on surfaces or in

Heterostuctures of 4-(chloromethyl)phenyltrichlorosilane and 5,10,15,20-tetra(4-pyridyl)-21H,23H-porphine prepared on Si(111) using particle lithography: Nanoscale characterization of the main steps of nanopatterning

• Phillip C. Chambers and
• Jayne C. Garno

Beilstein J. Nanotechnol. 2018, 9, 1211–1219, doi:10.3762/bjnano.9.112

• nanostructures measuring 500 nm, as revealed in the close-up topography and phase views (Figure 4b and 4c). There is little nonspecific binding of adsorbates on the OTS matrix areas between the nanostructures, as shown in the phase map of Figure 4c. An example cursor profile that was traced across two of the

Electro-optical interfacial effects on a graphene/π-conjugated organic semiconductor hybrid system

• Karolline A. S. Araujo,
• Luiz A. Cury,
• Matheus J. S. Matos,
• Thales F. D. Fernandes,
• Luiz G. Cançado and
• Bernardo R. A. Neves

Beilstein J. Nanotechnol. 2018, 9, 963–974, doi:10.3762/bjnano.9.90

• pair is photogenerated and liberates graphene adsorbates via hole recombination (e.g., h+ + O2− → O2 (gas)), releasing electrons that, then, contribute toward an effective n-doping [39][40]. The shorter the wavelength, the more effective such process is [39][40]. Thus, in the present case, which uses

• white light illumination, the shorter wavelengths should be responsible for most of this effect. The increase on the RA SAM potential might result from concomitant contributions of several mechanisms, including photo-electron generation via hole recombination with RA surface states and adsorbates

Facile chemical routes to mesoporous silver substrates for SERS analysis

• Elina A. Tastekova,
• Alexander Y. Polyakov,
• Anastasia E. Goldt,
• Alexander V. Sidorov,
• Alexandra A. Oshmyanskaya,
• Irina V. Sukhorukova,
• Dmitry V. Shtansky,
• Wolgang Grünert and
• Anastasia V. Grigorieva

Beilstein J. Nanotechnol. 2018, 9, 880–889, doi:10.3762/bjnano.9.82

• role as surfactant, partly blocking the nucleation at (100) facets if the prevalent growth mechanism is normal or lateral layer-by-layer growth [28]. Presumably, the PVP adsorbates remained at the Ag2O crystallite surface after the washing procedure. Remarkably, the porous polyhedron-like silver

• correspond to the metal state of silver [31]. Both characteristic energies are decreased slightly, probably, as a result of PVP adsorbates at the surface. The absence of a silver oxide phase at the surface is also beneficial for efficient surface plasmon resonance, which is strongly required for SERS. This

The effect of atmospheric doping on pressure-dependent Raman scattering in supported graphene

• Egor A. Kolesov,
• Mikhail S. Tivanov,
• Olga V. Korolik,
• Olesya O. Kapitanova,
• Xiao Fu,
• Hak Dong Cho,
• Tae Won Kang and
• Gennady N Panin

Beilstein J. Nanotechnol. 2018, 9, 704–710, doi:10.3762/bjnano.9.65

• . Keywords: adsorption; doping; graphene; pressure; Raman spectroscopy; substrate; Introduction Graphene is a promising material for a variety of applications due to its unique physical properties [1]. Among its other outstanding features, one can distinguish its strong sensitivity to adsorbates, leading to

• doping by adsorbates [13], and substrate-induced electrostatic doping [16]. The G and 2D peak positions upshifted by 5–8 cm−1 and the considerably low I2D/IG ratio of 1.3–1.4 for graphene transferred onto copper and Al2O3 could be explained by similar effects, which in this case, tend to be less

• graphene transferred to Cu and Al2O3 as typical conducting and dielectric materials, a stronger carrier density change was obtained for the latter. As the pressure decreases, removal of adsorbates from the surface of graphene on Al2O3 results in the Raman spectra parameters becoming close to those typical

Anchoring of a dye precursor on NiO(001) studied by non-contact atomic force microscopy

• Sara Freund,
• Antoine Hinaut,
• Nathalie Marinakis,
• Edwin C. Constable,
• Ernst Meyer,
• Catherine E. Housecroft and
• Thilo Glatzel

Beilstein J. Nanotechnol. 2018, 9, 242–249, doi:10.3762/bjnano.9.26

• non-contact atomic force microscopy at room temperature. Depending on the coverage, single molecules, groups of adsorbates with random or recognizable shapes, or islands of closely packed molecules were identified. Single molecules and self assemblies are resolved with submolecular resolution showing

Gas-assisted silver deposition with a focused electron beam

• Luisa Berger,
• Katarzyna Madajska,
• Iwona B. Szymanska,
• Katja Höflich,
• Mikhail N. Polyakov,
• Jakub Jurczyk,
• Carlos Guerra-Nuñez and
• Ivo Utke

Beilstein J. Nanotechnol. 2018, 9, 224–232, doi:10.3762/bjnano.9.24

• ]. This was explained by the presence of two different regimes within and outside the PE beam area. Within the PE beam area the electron density is orders of magnitude higher compared to the adjacent outside halo area (cf. Figure 1c). Within the PE beam area the adsorbates dissociate by electron

• interaction into deposited metal atoms and volatile, yet still physisorbed ligands. Due to the high electron flux within the PE beam area, the desorption rate of these volatile ligands is lower than their dissociation rate, resulting in a higher carbon content. Outside the PE beam area, the adsorbates still

• irradiates it again, thus the FEBID can continue with fresh adsorbates and less co-deposition of carbon. For further studies, box deposits were written with the same electron dose of 7.44 nC/µm2 but different dwell and refreshment times. On first sight it is visible that for short refreshment times as in

Comparative study of post-growth annealing of Cu(hfac)₂, Co₂(CO)₈ and Me₂Au(acac) metal precursors deposited by FEBID

• Marcos V. Puydinger dos Santos,
• Aleksandra Szkudlarek,
• Artur Rydosz,
• Carlos Guerra-Nuñez,
• Fanny Béron,
• Kleber R. Pirota,
• Stanislav Moshkalev,
• José Alexandre Diniz and
• Ivo Utke

Beilstein J. Nanotechnol. 2018, 9, 91–101, doi:10.3762/bjnano.9.11

• -established maskless nanopattering technique. It is based on the local dissociation of adsorbates upon the irradiation with electrons, combining the advantages of a direct-write process with the depositing possibility of a number of geometries at nanometric scale [1][2][3][4][5][6][7][8][9][10][11]. The

• electrons generated in the vicinity of the impinging primary beam, is transferred to the adsorbates. The dissociation yields both volatile ligand fragments (pumped away) and deposited non-volatile products (such as metals) [8][9][12][13]. FEBID has been recently used to define nanodevices for several

Optical contrast and refractive index of natural van der Waals heterostructure nanosheets of franckeite

• Patricia Gant,
• Foad Ghasemi,
• David Maeso,
• Carmen Munuera,
• Elena López-Elvira,
• Riccardo Frisenda,
• David Pérez De Lara,
• Gabino Rubio-Bollinger,
• Mar Garcia-Hernandez and
• Andres Castellanos-Gomez

Beilstein J. Nanotechnol. 2017, 8, 2357–2362, doi:10.3762/bjnano.8.235

• adsorbates between the layers. Very recently Molina-Mendoza et al. demonstrated mechanical and liquid-phase exfoliation of franckeite down to 3–4 unit cells and they fabricated field-effect devices, near infrared photodetectors and PN junctions [15]. Also, Velický et al. isolated single unit cell nanosheets