A nano-graphite cold cathode for an energy-efficient cathodoluminescent light source

• Alexander N. Obraztsov,
• Victor I. Kleshch and
• Elena A. Smolnikova

Beilstein J. Nanotechnol. 2013, 4, 493–500, doi:10.3762/bjnano.4.58

• emission intensity [13]. Starting to grow immediately on the Si substrate, these graphite crystallites have an excellent adhesion and electrical contact with the substrate. The mechanical strength and the excellent electrical conductivity at the contact between the nano-graphite flakes and the substrate

Characterization of electroforming-free titanium dioxide memristors

• John Paul Strachan,
• J. Joshua Yang,
• L. A. Montoro,
• C. A. Ospina,
• A. J. Ramirez,
• A. L. D. Kilcoyne,
• Gilberto Medeiros-Ribeiro and
• R. Stanley Williams

Beilstein J. Nanotechnol. 2013, 4, 467–473, doi:10.3762/bjnano.4.55

• . However, BF image analysis indicated that the Pt grains from the top electrode are larger than those of the bottom electrode, as seen in Figure 5a and Figure 5b. These grain size distributions were observed to be uniform within the junction, roughly 20 μm away at the Si3N4 window edge, and over the Si

• substrate outside of the window (as checked by scanning electron microscopy). This strongly suggests that the grain growth was initiated by self-heating in the thin film electrode itself. Conclusion We have seen that it is possible to reduce and nearly eliminate many of the damaging effects which had been

Micro- and nanoscale electrical characterization of large-area graphene transferred to functional substrates

• Gabriele Fisichella,
• Salvatore Di Franco,
• Patrick Fiorenza,
• Raffaella Lo Nigro,
• Fabrizio Roccaforte,
• Cristina Tudisco,
• Guido G. Condorelli,
• Nicolò Piluso,
• Noemi Spartà,
• Stella Lo Verso,
• Corrado Accardi,
• Cristina Tringali,
• Sebastiano Ravesi and
• Filippo Giannazzo

Beilstein J. Nanotechnol. 2013, 4, 234–242, doi:10.3762/bjnano.4.24

• = 75 ± 6 Ω) contributions have been determined. Since Rc clearly depends on the pad size, the specific contact resistance ρc = Rc·W normalized to the contact width was also evaluated, obtaining a value ρc = 15.1 ± 1.2 kΩ·μm. For graphene transferred onto the SiO2(300nm)/Si substrate, the n+-doped Si

• substrate can be employed as global back-gate (see schematic in Figure 5a) to induce an electrostatic shift of the Fermi level of graphene and, hence, to tune the carrier density of the material. In Figure 5b the resistance versus the distance between adjacent contacts is reported for different values of

Electronic and transport properties of kinked graphene

• Jesper Toft Rasmussen,
• Tue Gunst,
• Peter Bøggild,
• Antti-Pekka Jauho and
• Mads Brandbyge

Beilstein J. Nanotechnol. 2013, 4, 103–110, doi:10.3762/bjnano.4.12

• graphene sheet, and may open a route to band gap engineered devices [13][18][19][20][21]. Very recently, Wu et al. [21] showed how graphene on a Si substrate decorated with SiO2 nanoparticles induced local regions of strain and increased reactivity in a selective manner. Atomic hydrogen or other chemical

Nanostructure-directed chemical sensing: The IHSAB principle and the dynamics of acid/base-interface interaction

• James L. Gole and
• William Laminack

Beilstein J. Nanotechnol. 2013, 4, 20–31, doi:10.3762/bjnano.4.3

• diameters varying from 0.8 to 1.5 µm and pore depths varying from 10 to 30 µm. The micropores provide a medium for Fickian diffusion to the surface nanoporous layer. Before the anodizations, an insulation layer of SiC (≈1000 angstroms) is coated onto the c-Si substrate by PEVCD methods. Windows of size 2

Controlled positioning of nanoparticles on a micrometer scale

• Fabian Enderle,
• Oliver Dubbers,
• Alfred Plettl and
• Paul Ziemann

Beilstein J. Nanotechnol. 2012, 3, 773–777, doi:10.3762/bjnano.3.86

• -N7500-18, Allresist, 6000 rpm, thickness approximately 300 nm) is spin coated above the primarily deposited Au NPs. Prior to this step, it is important to give the Si substrate with the NPs a short HF dip (2% HF, 10 s), which significantly enhances the adhesion of the resist. After a standard prebake of

• square lattice with mutual distances in the micrometer range. However, to enhance visibility of these NPs in an overview SEM image, the particles are used as a mask during a subsequent reactive ion etching (RIE) of the Si substrate transforming the NPs into nanopillars. The result is demonstrated in

• Au NPs is used as a mask for a subsequent reactive-etching process delivering correspondingly arranged Si nanopillars. SEM image of Au nanoparticles (average diameter 13 nm, interparticle distance 102 nm) deposited on top of a Si substrate by applying an approach based on self-organization of

Ordered arrays of nanoporous gold nanoparticles

• Dong Wang,
• Ran Ji,
• Arne Albrecht and
• Peter Schaaf

Beilstein J. Nanotechnol. 2012, 3, 651–657, doi:10.3762/bjnano.3.74

• deposited metal films and the Si substrate. Au/Ag bilayers with different layer thicknesses (10 nm/20 nm, 10 nm/25 nm, 10 nm/30 nm, 15 nm/25 nm, and 15 nm/30 nm) were deposited onto the prepatterned substrates by e-beam evaporation, and then annealed at 700 °C in Ar for 15 min to induce dewetting. This

• with 15 nm Au/20 nm Ag bilayers deposited onto a flat Si substrate with 100 nm thick, thermally grown SiO2 layer was annealed at 900 °C in Ar for 15 min and then dealloyed for comparison. Dewetting on a prepatterned substrate takes place at a lower annealing temperature [24], and a higher temperature

• samples in a 65 wt % HNO3 solution at 21 °C for 5 min. A reference sample (15 nm Au/20 nm Ag bilayers on a flat SiO2/Si substrate) was processed by annealing at 900 °C in Ar for 15 min and then submerging in a 65 wt % HNO3 solution at 21 °C for 5 min. The SiO2 thickness of the reference sample is 100 nm

Synthesis and electrical characterization of intrinsic and in situ doped Si nanowires using a novel precursor

• Wolfgang Molnar,
• Alois Lugstein,
• Tomasz Wojcik,
• Peter Pongratz,
• Norbert Auner,
• Christian Bauch and
• Emmerich Bertagnolli

Beilstein J. Nanotechnol. 2012, 3, 564–569, doi:10.3762/bjnano.3.65

• oxide on top of a Si substrate can also be removed during growth by using SiCl4 as a precursor. Gaseous HCl, a byproduct of SiCl4 decomposition in the presence of H2, etches the native oxide, providing a clean substrate surface for epitaxial NW growth. The same effect can be utilized by intentionally

Directed deposition of silicon nanowires using neopentasilane as precursor and gold as catalyst

• Britta Kämpken,
• Verena Wulf,
• Norbert Auner,
• Marcel Winhold,
• Michael Huth,
• Daniel Rhinow and
• Andreas Terfort

Beilstein J. Nanotechnol. 2012, 3, 535–545, doi:10.3762/bjnano.3.62

• are due to the high reflectivity of the uncovered Si substrate. SEM images (different magnifications) of Si NWs obtained from UV-patterned spin-coated “liquid bright gold” films after annealing at 650 °C, followed by treatment with NPS at 375 °C for 1 h. SEM image of the border region of a Si NW

Imaging ultra thin layers with helium ion microscopy: Utilizing the channeling contrast mechanism

• Gregor Hlawacek,
• Vasilisa Veligura,
• Stefan Lorbek,
• Tijs F. Mocking,
• Antony George,
• Raoul van Gastel,
• Harold J. W. Zandvliet and
• Bene Poelsema

Beilstein J. Nanotechnol. 2012, 3, 507–512, doi:10.3762/bjnano.3.58

• surface layer of the relevant material (SiO2, PFS, or MS). As a consequence of the identical strip width for PFS and MS strips, we do not know a priori which stripe is which. However, we assign the bright structureless areas to the uncovered SiO2/Si substrate. It is understood that because of the

Structural, electronic and photovoltaic characterization of multiwalled carbon nanotubes grown directly on stainless steel

• Luca Camilli,
• Manuela Scarselli,
• Silvano Del Gobbo,
• Paola Castrucci,
• Eric Gautron and
• Maurizio De Crescenzi

Beilstein J. Nanotechnol. 2012, 3, 360–367, doi:10.3762/bjnano.3.42

• an ohmic contact at the back of the silicon substrate; and (c) producing a MWCNT film of suitable thickness, thus allowing the photons to reach the heterojunction with the Si substrate. Conclusion In this paper we have shown a facile method to grow CNTs by chemical vapour deposition directly on SS

• characteristic, and are due to the quasi-one-dimensionality of the CNTs. We have exploited the photovoltaic activity of MWCNTs in a device made of MWCNTs airbrushed onto a Si substrate. We evidenced the formation of a Schottky junction at the interface. EQE spectra and J–V characteristics were acquired with two

Mesoporous MgTa₂O₆ thin films with enhanced photocatalytic activity: On the interplay between crystallinity and mesostructure

• Jin-Ming Wu,
• Igor Djerdj,
• Till von Graberg and
• Bernd M. Smarsly

Beilstein J. Nanotechnol. 2012, 3, 123–133, doi:10.3762/bjnano.3.13

• observation. The corresponding height profile obtained from the AFM image suggests that the depth of the randomly distributed round concaves was ca. 60 nm. The film thickness was estimated to be ca. 200 nm; therefore, the ordered mesoporous MgTa2O6 film thoroughly covered the Si substrate. The distance

Electron-beam patterned self-assembled monolayers as templates for Cu electrodeposition and lift-off

• Zhe She,
• Andrea DiFalco,
• Georg Hähner and
• Manfred Buck

Beilstein J. Nanotechnol. 2012, 3, 101–113, doi:10.3762/bjnano.3.11

• shows a compilation of AFM images comparing the structure as deposited on a MBP0 patterned Au/Si substrate with the one transferred to the epoxy glue. Parallel lines about 1 μm apart were written into the SAM by e-beam lithography. As inferred from the difference between the grooves, where the cross

• on Au/Si. Potentials of I–t curves in (a) are −0.5 V (black line), −0.6 V (red dashed line) and −0.7 V (green dotted line) and in (b) −0.7 V for 1 s, −0.35 V for 10 s on MBP0/Au/Si. For comparison an I–t curve for a clean Au/Si substrate and identical deposition conditions is shown in the inset. (c,d

• height profile along the line. Deposition conditions: −0.7 V for 1 s, −0.25 V for 20 s (a); −0.7 V for 1 s, −0.35 V for 10 s (b). SEM images of a SAM templated copper deposit on the original MBP0 coated Au/Si substrate (a) and after transfer to epoxy glue (b). The passivating line of the cross-linked SAM

Direct-write polymer nanolithography in ultra-high vacuum

• Woo-Kyung Lee,
• Minchul Yang,
• Arnaldo R. Laracuente,
• William P. King,
• Lloyd J. Whitman and
• Paul E. Sheehan

Beilstein J. Nanotechnol. 2012, 3, 52–56, doi:10.3762/bjnano.3.6

• thicknesses deposited in UHV. The lower deposition temperature also reduces the risk of thermal damage when applied to pre-fabricated devices. While heating the probe to the vacuum melting temperature of the PDDT, the tip was rasterized across the “as is” native oxide Si substrate at different speeds. We

• the relatively high speed of 20 µm/s, only a single monolayer is deposited as shown by the line average to the right of the image. Lower speeds deposit thicker polymer lines as shown by line averages in (c). The polymer deposit heights and widths of PDDT deposited onto Si substrate (non-UHV prepared

• ) as a function of scanning speed. Both the height and width decrease monotonically with tip speed. (a) Deposition onto the UHV prepared Si substrate in UHV shows the polymer lying on its side. (b) Polymer deposited across a Si step edge an atom thick. (c) The cross section [pale blue line in (b

Mechanical characterization of carbon nanomembranes from self-assembled monolayers

• Xianghui Zhang,
• André Beyer and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2011, 2, 826–833, doi:10.3762/bjnano.2.92

• position or tilt. (a) Schematic diagram of a bulge test in AFM; (b) Schematic of a biphenylthiol CNM on a window-structured Si substrate, which is suspended over an orifice; (c) AFM image of a nonpressurized CNM in contact mode and the line profile with a downward deformation of 200 nm; (d) AFM image of

Nanostructured, mesoporous Au/TiO₂ model catalysts – structure, stability and catalytic properties

• Matthias Roos,
• Dominique Böcking,
• Kwabena Offeh Gyimah,
• Gabriela Kucerova,
• Joachim Bansmann,
• Johannes Biskupek,
• Ute Kaiser,
• Nicola Hüsing and
• R. Jürgen Behm

Beilstein J. Nanotechnol. 2011, 2, 593–606, doi:10.3762/bjnano.2.63

• mode. By mechanically removing part of the Au/TiO2 film, we generated a free-standing edge of the film on the Si substrate around the sample center, whose height was measured by AFM. Evaluation of single line profiles across the step edge between the bare Si substrate and the region of the intact Au

• measurements on Au/TiO2 thin-film catalysts. These probe the entire film thickness, and even into the Si substrate, as evident from the presence of a visible Si peak. Hence, despite a similar Au loading process and process parameters, the DP process leads to significantly higher Au contents on the TiO2 film

Distinguishing magnetic and electrostatic interactions by a Kelvin probe force microscopy–magnetic force microscopy combination

• Miriam Jaafar,
• Oscar Iglesias-Freire,
• Luis Serrano-Ramón,
• Manuel Ricardo Ibarra,
• Jose Maria de Teresa and
• Agustina Asenjo

Beilstein J. Nanotechnol. 2011, 2, 552–560, doi:10.3762/bjnano.2.59

• when the tip is on top of the Co wire and to about −320 mV in the case of the Si substrate. Thus, according to these results, by measuring the frequency shift on top of the Co wire at Vbias = 320 mV (horizontal black dashed line) we should detect only the magnetic signal without any electrostatic

Formation of precise 2D Au particle arrays via thermally induced dewetting on pre-patterned substrates

• Dong Wang,
• Ran Ji and
• Peter Schaaf

Beilstein J. Nanotechnol. 2011, 2, 318–326, doi:10.3762/bjnano.2.37

• symmetry (substrate B). SEM images of induced particles on the flat SiO2/Si substrate after dewetting of the 5 nm (a) and 60 nm (b) thick Au films. (c) Histograms of particle size distributions produced by the dewetting of the 5 nm, 10 nm, 20 nm, 30 nm, 40 nm, and 60 nm thick Au films on the flat SiO2/Si

• substrate A have a spatial period of 513 nm and a depth of 150 nm. The holes in the substrate B have the same spatial period of 513 nm, a diameter of about 490 nm, and a depth of 120 nm. Figure 2 shows the SEM images of the Au particles formed from the 5 nm and 60 nm thick Au films on a flat SiO2/Si

• substrate. Usually, flat substrates lead to a broad distribution of particle size and spacing of the dewetted particles. Figure 2c shows the particle size distributions produced by dewetting of Au films with thicknesses from 5 nm to 60 nm on the flat substrates. Both, mean particle size and the width

Extended X-ray absorption fine structure of bimetallic nanoparticles

• Carolin Antoniak

Beilstein J. Nanotechnol. 2011, 2, 237–251, doi:10.3762/bjnano.2.28

• -hexane with surfactants, precipitated out and centrifuged once again. This can be repeated several times, until a stable dispersion of nanoparticles in n-hexane is obtained. The nanoparticles can be brought onto a naturally oxidised Si substrate using the spin coating technique, dip coating or just by

Single-pass Kelvin force microscopy and dC/dZ measurements in the intermittent contact: applications to polymer materials

• Sergei Magonov and
• John Alexander

Beilstein J. Nanotechnol. 2011, 2, 15–27, doi:10.3762/bjnano.2.2

• on the polymer films by a sharp wooden stick and we verified that a substrate-specific morphology was present at the bottom of scratches. At the scratched locations one can measure the film thickness and a relative electrical response of the polymer and Si substrate. All prepared samples were glued

• illustrated in Figure 2B which shows the dependence of phase changes as a function of DC bias voltage between a conducting probe and different locations of the F14H20 adsorbate on Si substrate. The phase-versus-DC-bias curve (colored blue) was detected when the probe was over a domain of the toroid-like self

• voltages needed for nullification of the electrostatic is the main function of KFM. The topography and surface potential images, which were recorded on the F14H20 adsorbate on Si substrate, are presented in Figure 3. These images were obtained with Asp just above (Figure 3A) and below (Figure 3B) its value

Magnetic coupling mechanisms in particle/thin film composite systems

• Giovanni A. Badini Confalonieri,
• Philipp Szary,
• Durgamadhab Mishra,
• Maria J. Benitez,
• Mathias Feyen,
• An Hui Lu,
• Leonardo Agudo,
• Gunther Eggeler,
• Oleg Petracic and
• Hartmut Zabel

Beilstein J. Nanotechnol. 2010, 1, 101–107, doi:10.3762/bjnano.1.12

• Kohlenforschung, D-45470 Mülheim an der Ruhr, Germany Institut für Werkstoffe, Ruhr-Universität Bochum, D-44780 Bochum, Germany 10.3762/bjnano.1.12 Abstract Magnetic γ-Fe2O3 nanoparticles with a mean diameter of 20 nm and size distribution of 7% were chemically synthesized and spin-coated on top of a Si

• -substrate. As a result, the particles self-assembled into a monolayer with hexagonal close-packed order. Subsequently, the nanoparticle array was coated with a Co layer of 20 nm thickness. The magnetic properties of this composite nanoparticle/thin film system were investigated by magnetometry and related

Preparation and characterization of supported magnetic nanoparticles prepared by reverse micelles

• Ulf Wiedwald,
• Luyang Han,
• Johannes Biskupek,
• Ute Kaiser and
• Paul Ziemann

Beilstein J. Nanotechnol. 2010, 1, 24–47, doi:10.3762/bjnano.1.5

• measured for CoCl2 loaded PS(1779)-P2VP(857) reverse micelles. All spectra shown in Figure 5 are normalized to the total Si-2p signal intensity of the substrate. In the initial state PS-P2VP molecules dominate the survey scan proving the continuous coverage of the Si substrate by reverse micelles. The Co

• micelle shell, strongly decreases relative to the Si substrate even after oxygen exposure for only 30 s. After 5 min exposure time, the C-1s intensity dropped below the detection limit, while after 10 min a clear Co2+ spectrum can be observed. At this stage the particles simultaneously nucleate to form Co

• Figure 11 (b) which nicely demonstrates the validity of the approach. Note that the larger error bars of Co NPs on Si substrate are due to the lower saturation magnetization of the sample (10–9 Am2). 3.3 FePt alloy particles For the magnetic characterization of FePt alloy particles we chose X-ray