Advances in the fabrication of graphene transistors on flexible substrates

• Gabriele Fisichella,
• Stella Lo Verso,
• Silvestra Di Marco,
• Vincenzo Vinciguerra,
• Emanuela Schilirò,
• Salvatore Di Franco,
• Raffaella Lo Nigro,
• Fabrizio Roccaforte,
• Amaia Zurutuza,
• Alba Centeno,
• Sebastiano Ravesi and
• Filippo Giannazzo

Beilstein J. Nanotechnol. 2017, 8, 467–474, doi:10.3762/bjnano.8.50

• smoother substrates. However, it is still possible to identify wrinkles, as indicated by the dashed green circle in Figure 4a. A schematic illustration of the graphene channel fabricated over the FET gate contact is reported in Figure 4b. After patterning the graphene channel, the source and drain contacts

• determine the total electrical resistance, RTOT, between source and drain contacts are also illustrated in Figure 4d. Here, the gate-bias-dependent graphene channel resistance, Rch(Vg), the source and drain contact resistance, Rc, and the access resistance, Racc, associated with the ungated graphene access

• regions between the channel and the source and drain contacts (Lacc = 20 µm length per access region) are shown. The total resistance resulting from the series combination of these contributions can be expressed as: The capacitance of the Al2O3 dielectric deposited by ALD on the flexible substrate was

Study of the surface properties of ZnO nanocolumns used for thin-film solar cells

• Neda Neykova,
• Jiri Stuchlik,
• Karel Hruska,
• Ales Poruba,
• Zdenek Remes and
• Ognen Pop-Georgievski

Beilstein J. Nanotechnol. 2017, 8, 446–451, doi:10.3762/bjnano.8.48

• vertical geometry of these textures, the optical thickness is dictated by the height of the NCs, such that most of the light traversing the cell sees an absorber-layer thickness approximately equal to the NC height. In contrast, as the front and back TCO contacts are interpenetrating, the inter-electrode

Impact of contact resistance on the electrical properties of MoS₂ transistors at practical operating temperatures

• Filippo Giannazzo,
• Gabriele Fisichella,
• Aurora Piazza,
• Salvatore Di Franco,
• Giuseppe Greco,
• Simonpietro Agnello and
• Fabrizio Roccaforte

Beilstein J. Nanotechnol. 2017, 8, 254–263, doi:10.3762/bjnano.8.28

• voltage (Vth). This paper reports a detailed electrical characterization of back-gated multilayer MoS2 transistors with Ni source/drain contacts at temperatures from T = 298 to 373 K, i.e., the expected range for transistor operation in circuits/systems, considering heating effects due to inefficient

• demonstrated using single [3] and multilayers of MoS2 [4]. MoS2 thin films, obtained either by cleavage from the bulk material or by chemical vapor deposition, are typically unintentionally n-type doped. Since well-assessed methods for doping enrichment of MoS2 under source/drain contacts are still lacking

• , MoS2 transistors are mostly fabricated by deposition of metals directly on the unintentionally doped material, resulting in the formation of Schottky contacts. Experimental investigations showed that both low work function (e.g., Sc, Ti) and high work function (e.g., Ni, Pt) metals mostly exhibit a

Influence of hydrofluoric acid treatment on electroless deposition of Au clusters

• Rachela G. Milazzo,
• Antonio M. Mio,
• Giuseppe D’Arrigo,
• Emanuele Smecca,
• Alessandra Alberti,
• Gabriele Fisichella,
• Filippo Giannazzo,
• Corrado Spinella and
• Emanuele Rimini

Beilstein J. Nanotechnol. 2017, 8, 183–189, doi:10.3762/bjnano.8.19

• shown quite interesting applications in the fields of Si nanowire (SiNW) catalysis [1][2][3], metal-assisted etching (MAE) [4] or even as electrical contacts in standard miniaturized devices [5]. Their ability to display enhanced surface plasmon resonance (SPR) at optical frequencies makes them

Studying friction while playing the violin: exploring the stick–slip phenomenon

• Santiago Casado

Beilstein J. Nanotechnol. 2017, 8, 159–166, doi:10.3762/bjnano.8.16

• generally understood to be the resistance to the sliding motion of objects. It is an everyday life phenomenon that originates from the atomic-scale asperities found at the interfacial contacts [1]. However, substantially different physical descriptions apply when friction is studied at the nanoscale

Sensitive detection of hydrocarbon gases using electrochemically Pd-modified ZnO chemiresistors

• Elena Dilonardo,
• Michele Penza,
• Marco Alvisi,
• Gennaro Cassano,
• Cinzia Di Franco,
• Francesco Palmisano,
• Luisa Torsi and
• Nicola Cioffi

Beilstein J. Nanotechnol. 2017, 8, 82–90, doi:10.3762/bjnano.8.9

• -like ZnO-based chemiresistive gas sensor. After the annealing at 550 °C, pristine and Pd-modified ZnO were redispersed in ACN and drop-cast on alumina substrates to obtain sensing layers between gold contacts. These assemblies were subsequently thermally stabilized at 300 °C for 2 h. The description of

Structural and tribometric characterization of biomimetically inspired synthetic "insect adhesives"

• Matthias W. Speidel,
• Malte Kleemeier,
• Andreas Hartwig,
• Klaus Rischka,
• Angelika Ellermann,
• Rolf Daniels and
• Oliver Betz

Beilstein J. Nanotechnol. 2017, 8, 45–63, doi:10.3762/bjnano.8.6

• viscosity of the liquid, in thin films, friction can be enhanced by processes such as (1) the formation of dry contacts by dewetting, (2) the solid-like behaviour of the liquid attributable to non-Newtonian properties, (3) the molecular ordering of the liquid at zones at which the film becomes thinner than

• a few monolayers and (4) the penetration of surface irregularities through the liquid film resulting in solid–solid contacts (cf. discussion in [55]). The influence of film thickness can also be seen in our experiments. Although we assume that in all of our experiments, we measured in the regimes of

Sub-nanosecond light-pulse generation with waveguide-coupled carbon nanotube transducers

• Felix Pyatkov,
• Svetlana Khasminskaya,
• Vadim Kovalyuk,
• Frank Hennrich,
• Manfred M. Kappes,
• Gregory N. Goltsman,
• Wolfram H. P. Pernice and
• Ralph Krupke

Beilstein J. Nanotechnol. 2017, 8, 38–44, doi:10.3762/bjnano.8.5

• -coupled CNT transducers to electrical signals and analyze the optical pulses propagating in the waveguide. Results and Discussion Fabrication of waveguide-integrated CNT emitters Our waveguide-coupled CNT (WG-CNT) transducers consist of three components: a rib waveguide, metallic contacts next to the

• waveguide, and metallic single-walled carbon nanotubes (SWCNTs) placed on top of the waveguide, bridging the contacts (Figure 1a). We use the design and fabrication approach for our samples that has been described in detail elsewhere [4]. Both electrodes and waveguides were defined using several steps of

• electron beam lithography on top of Si3N4/SiO2/Si substrate. Au/Cr contacts were produced by physical vapor deposition, and 600 nm wide, half-etched Si3N4-waveguides were formed with reactive ion etching. A typical sample contains tens of contact pairs and CNTs that were placed in between using

Solvent-mediated conductance increase of dodecanethiol-stabilized gold nanoparticle monolayers

• Patrick A. Reissner,
• Jean-Nicolas Tisserant,
• Antoni Sánchez-Ferrer,
• Raffaele Mezzenga and
• Andreas Stemmer

Beilstein J. Nanotechnol. 2016, 7, 2057–2064, doi:10.3762/bjnano.7.196

• 0.76 Å−1 for alkane chains with one and two chemisorbed contacts [30]. Since Δa = 0.5 nm for immersion in EtOH, the conductance would increase by a factor between 190 and 45. On average, the conductance of our monolayers increased by 36 during EtOH immersion, which is slightly lower than the calculated

• samples were rinsed with THF or EtOH and dried under nitrogen flow [3]. Contact deposition Electric contacts were applied by shadow mask evaporation. We aligned a 400 mesh TEM grid with the printed lines on the substrate and deposited 3 nm titanium and 65 nm gold by electron-beam evaporation at a pressure

Zigzag phosphorene nanoribbons: one-dimensional resonant channels in two-dimensional atomic crystals

• Carlos. J. Páez,
• Dario. A. Bahamon,
• Ana L. C. Pereira and
• Peter. A. Schulz

Beilstein J. Nanotechnol. 2016, 7, 1983–1990, doi:10.3762/bjnano.7.189

• = 57 nanoribbon, as a function of the energy. In order to avoid any coupling between the edge states the width of the nanoribbon in the contacts is also NZ = 60. Transmission plateaus above and below the edge states band are shown, for the sake of completeness, since these structures are of entirely

• ). When mZ is further diminished, the barriers to the upper-edge contacts become too large, but now the coupling to the lower edge becomes relevant. For mZ ≤ 15 transmission shows asymmetric Fano-like resonances at the low-energy side and sharp anti-resonances at higher energies within the central band

• (keeping the central band of the contacts unaltered). In our constriction the role of both channels (discrete states and continuum at the upper and lower edges) can be made explicit by picturing the local density of states (LDOS) in Figure 4, at the energy values indicated by arrows 1, 2, 3 and 4 in Figure

Monolayer graphene/SiC Schottky barrier diodes with improved barrier height uniformity as a sensing platform for the detection of heavy metals

• Ivan Shtepliuk,
• Jens Eriksson,
• Volodymyr Khranovskyy,
• Tihomir Iakimov,
• Anita Lloyd Spetz and
• Rositsa Yakimova

Beilstein J. Nanotechnol. 2016, 7, 1800–1814, doi:10.3762/bjnano.7.173

• behaviour and a good quality of ohmic palladium–graphene contacts. Keeping in mind the strong sensitivity of graphene to analytes we propose the possibility to use the graphene/SiC Schottky diode as a sensing platform for the recognition of toxic heavy metals. Using density functional theory (DFT

• characterization provides evidence for the formation of monolayered graphene [51]. The 1 ML coverage is found to be about 99%, thereby implying the high uniformity of the graphene thickness. To avoid the necessity to etch parts of the graphene coverage in order to form the ohmic contacts to SiC, we did not utilize

• the lateral Schottky diode structure and mainly focused on designing vertical devices. It might be expected that the vertical structure has some advantages over the lateral device, since it offers a simpler design and a higher breakdown voltage (because of larger area efficiency). Palladium contacts

Active and fast charge-state switching of single NV centres in diamond by in-plane Al-Schottky junctions

• Christoph Schreyvogel,
• Vladimir Polyakov,
• Sina Burk,
• Helmut Fedder,
• Andrej Denisenko,
• Felipe Fávaro de Oliveira,
• Ralf Wunderlich,
• Jan Meijer,
• Verena Zuerbig,
• Jörg Wrachtrup and
• Christoph E. Nebel

Beilstein J. Nanotechnol. 2016, 7, 1727–1735, doi:10.3762/bjnano.7.165

• channel, NV centres are quenched, i.e., switched to the nonfluorescent state NV+ as proved by PL-intensity mappings which show no bright spots (Figure 1d). For fabricating a two-dimensional Schottky diode structure, aluminium (Al) and gold (Au) contacts with a thickness of 200 nm each were deposited onto

• the diamond surface using photolithography with subsequent thermal evaporation of the metals. Al is a Schottky contact showing a barrier height of 570 meV and Au is an Ohmic contact [18]. The contacts exhibit dimensions of 1 mm × 300 µm and were separated from each other by 400 µm. In order to have a

• defined conductive channel between the Al and Au contacts, the channel region including the contacts were protected with a photoresist and then the whole diamond surface surrounding the channel area were O-terminated via exposition to oxygen plasma. After lift-off process of the photoresist, the

Thickness-modulated tungsten–carbon superconducting nanostructures grown by focused ion beam induced deposition for vortex pinning up to high magnetic fields

• Ismael García Serrano,
• Javier Sesé,
• Isabel Guillamón,
• Hermann Suderow,
• Sebastián Vieira,
• Manuel Ricardo Ibarra and
• José María De Teresa

Beilstein J. Nanotechnol. 2016, 7, 1698–1708, doi:10.3762/bjnano.7.162

• , one sample with 120 nm pitch and two samples with 140 nm pitch. The area of the W–C films is 20 × 5 μm2 and the distance between the voltage probes is 5 μm. The Pt contacts under the superconducting film have been designed to allow for the growth of the W–C film to be started on a flat surface. For

• that, first, substrate FIB milling (200 nm deep and 1 μm wide) is performed in order to dig trenches to be subsequently filled with Pt contacts grown by FIBID using a (CH3)3PtCpCH3 precursor. As the surface of the Pt contacts is at the same height as the substrate’s top surface, the superconducting

• film starts the growth on a flat surface. In the final step, the linear Pt contacts are soldered to the Ti pads by the addition of thick, square, Pt deposits by FIBID. (a) Scheme of the experiment performed to measure the electrical resistance under perpendicular magnetic field. Due to the Lorentz

Analysis of self-heating of thermally assisted spin-transfer torque magnetic random access memory

• Austin Deschenes,
• Sadid Muneer,
• Mustafa Akbulut,
• Ali Gokirmak and
• Helena Silva

Beilstein J. Nanotechnol. 2016, 7, 1676–1683, doi:10.3762/bjnano.7.160

• different heat paths through metal and passivation layers, the configurations with passivation–Cu contacts (I, III) are simulated with and without thermal boundary resistances (TBR) applied on the passivation–Cu interfaces. This TBR is modeled as a 1 nm thick virtual layer with a thermal conductivity of

Sb₂S₃ grown by ultrasonic spray pyrolysis and its application in a hybrid solar cell

• Erki Kärber,
• Atanas Katerski,
• Ilona Oja Acik,
• Arvo Mere,
• Valdek Mikli and
• Malle Krunks

Beilstein J. Nanotechnol. 2016, 7, 1662–1673, doi:10.3762/bjnano.7.158

• P3HT layer remained below 400 nm, as estimated from SEM images. The Au layer was deposited onto the P3HT by thermal evaporation of metallic Au for 10 min under a pressure of 2·10−6 Torr through a metal mask with a number of holes that had an area of 1.7 mm2 each. Alternatively, larger contacts of 1 cm2

Nanostructured germanium deposited on heated substrates with enhanced photoelectric properties

• Ionel Stavarache,
• Valentin Adrian Maraloiu,
• Petronela Prepelita and
• Gheorghe Iordache

Beilstein J. Nanotechnol. 2016, 7, 1492–1500, doi:10.3762/bjnano.7.142

• ) observed in the absence of light can be the result of the serial combination of these interface junctions that can act as rectifying diode-like contacts. It is known that the chemical reduction of GeOx plays an important role and represents the major mechanism to produce size-controlled Ge-nps, embedded

Three-gradient regular solution model for simple liquids wetting complex surface topologies

• Sabine Akerboom,
• Marleen Kamperman and
• Frans A. M. Leermakers

Beilstein J. Nanotechnol. 2016, 7, 1377–1396, doi:10.3762/bjnano.7.129

• the dimensionless Flory–Huggins interaction parameter, which is an Archimedean-like parameter needed for unlike contacts: A positive value means that LL contacts and VV ‘contacts’ are favoured over LV ones and this implies a tendency towards demixing. When we assume random mixing (mean-field

• -field approximation is now applied along lattice layers. The angular brackets in the last term indicate that in the interaction term “curvature” information is included, which is needed to evaluate the number of liquid–vacancy contacts in the presence of density gradients. In continuous language, we

Functional diversity of resilin in Arthropoda

• Jan Michels,
• Esther Appel and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2016, 7, 1241–1259, doi:10.3762/bjnano.7.115

• pads on substrates depends on the ability of the pads to adapt to the surface topography. In this context, specific micro- and nanostructures can enhance the quality of the contact [97][98][99][100][101]. In the case of attachment on rough substrates, multiple contacts, being formed by some adhesive

• systems, provide great advantages [102]. The formation of multiple contacts, which contribute to an increase of the overall length of the total peeling line, is facilitated by a hierarchical organisation of the attachment structures [103]. It was shown that the combination of thin tape-like contact tips

• ][107]. As a result of this, the functional advantages achieved through multiple adhesive contacts can be strongly reduced [103]. Accordingly, the composition and the properties of the material of insect adhesive setae represent an optimisation problem. There is evidence that during the evolution

Preparation of alginate–chitosan–cyclodextrin micro- and nanoparticles loaded with anti-tuberculosis compounds

• Albert Ivancic,
• Fliur Macaev,
• Fatma Aksakal,
• Veaceslav Boldescu,
• Serghei Pogrebnoi and
• Gheorghe Duca

Beilstein J. Nanotechnol. 2016, 7, 1208–1218, doi:10.3762/bjnano.7.112

• interactions with isoconazole. Multiple hydrophobic contacts of amino acids with the inhibitor were indicated by green spheres in Figure 12b. Frontier molecular orbital analyses The analysis of specificity of the enzyme–ligand interaction is closely related to the analysis of frontier orbitals (HOMO and LUMO

In situ characterization of hydrogen absorption in nanoporous palladium produced by dealloying

• Eva-Maria Steyskal,
• Christopher Wiednig,
• Norbert Enzinger and
• Roland Würschum

Beilstein J. Nanotechnol. 2016, 7, 1197–1201, doi:10.3762/bjnano.7.110

• actuation might influence R: An expansion during hydrogenation may disconnect electrical contacts in the nanoporous network, leading to a resistance increase. Such a mechanical effect would also explain the noisy R-signal due to immediate resistance changes caused by opening/closing connections. Since

Role of solvents in the electronic transport properties of single-molecule junctions

• Katharina Luka-Guth,
• Sebastian Hambsch,
• Andreas Bloch,
• Philipp Ehrenreich,
• Bernd Michael Briechle,
• Filip Kilibarda,
• Torsten Sendler,
• Dmytro Sysoiev,
• Thomas Huhn,
• Artur Erbe and
• Elke Scheer

Beilstein J. Nanotechnol. 2016, 7, 1055–1067, doi:10.3762/bjnano.7.99

• solvents that are commonly used in the field of molecular electronics (ethanol, toluene, mesitylene, 1,2,4-trichlorobenzene, isopropanol, toluene/tetrahydrofuran mixtures) for the study of single-molecule contacts of functional molecules. We present measurements of the conductance as a function of gap

• conclusions is that stable junctions may form from solvents as well and that both conductance–distance traces and current–voltage characteristics have to be studied to distinguish between contacts of solvent molecules and of molecules under study. Keywords: electrochemical environment; mechanically

• ][8]. A very fruitful method for gathering statistical information on the transport behaviour of single-molecule junctions is the repeated formation and breakage of atomic contacts immersed in a solution containing the molecules under investigation in a suitable solvent. The dissolution of the

Advanced atomic force microscopy techniques III

• Thilo Glatzel and
• Thomas Schimmel

Beilstein J. Nanotechnol. 2016, 7, 1052–1054, doi:10.3762/bjnano.7.98

• several transitions in the friction coefficient with increasing load have been found on Au(111) in sulfuric acid electrolyte containing Cu ions by Helmut Baltruschat an co-workers [24] and the stiffness of micron-sized sphere-plate contacts was studied by Diethelm Johannsmann et al. by employing high

Reorientation of single-wall carbon nanotubes in negative anisotropy liquid crystals by an electric field

• Amanda García-García,
• Ricardo Vergaz,
• José F. Algorri,
• Gianluigi Zito,
• Teresa Cacace,
• Antigone Marino,
• José M. Otón and
• Morten A. Geday

Beilstein J. Nanotechnol. 2016, 7, 825–833, doi:10.3762/bjnano.7.74

• could be caused by SWCNTs that do not recover their original planar orientation. As these SWCNTs are in a position perpendicular to the contacts, the electron transport is facilitated by the longitudinal axis. Threshold voltage In order to determine a potential threshold voltage for the SWCNT switching

Assembling semiconducting molecules by covalent attachment to a lamellar crystalline polymer substrate

• Rainhard Machatschek,
• Patrick Ortmann,
• Renate Reiter,
• Stefan Mecking and
• Günter Reiter

Beilstein J. Nanotechnol. 2016, 7, 784–798, doi:10.3762/bjnano.7.70

• intrinsic electronic properties of a broad range of semiconducting molecules. However, the typically rather small size of polymer single crystals represents a drawback of the method described above. This small size complicates the application of electrical contacts to the device. In order to overcome this

• nanocrystals with packing densities of about 0.78, having a size of several thousand square micrometers. While the application of electrical contacts to these layers may be difficult, these layers of nanocrystals are rather smooth and covered with functional groups allowing for covalent attachment of molecules

Thermo-voltage measurements of atomic contacts at low temperature

• Ayelet Ofarim,
• Bastian Kopp,
• Thomas Möller,
• León Martin,
• Johannes Boneberg,
• Paul Leiderer and
• Elke Scheer

Beilstein J. Nanotechnol. 2016, 7, 767–775, doi:10.3762/bjnano.7.68

• atomic-sized gold contacts at low temperature. For these measurements a mechanically controllable break junction (MCBJ) system is used and a laser source generates a temperature difference of a few kelvins across the junction to create a thermo-voltage. Since the temperature difference enters directly

• measurement of the resistance change due to laser heating of sensor leads on both sides next to the junction. Our results for the measured thermopower are in agreement with recent reports in the literature. Keywords: atomic contacts; finite element simulations; laser heating; low temperature; mechanically

• system [5][6]. S can adopt both signs and typical values for single-atom and single-molecule contacts range from nV per K to several µV per K. So far several approaches for thermo-voltage measurements of atomic-scale devices have been performed successfully [7][8][9][10][11][12][13][14][15][16][17