Electrical response of liquid crystal cells doped with multi-walled carbon nanotubes

• Amanda García-García,
• Ricardo Vergaz,
• José F. Algorri,
• Xabier Quintana and
• José M. Otón

Beilstein J. Nanotechnol. 2015, 6, 396–403, doi:10.3762/bjnano.6.39

• set of a capacitor and a resistor (Figure 2) [22]. Every circuit element can be matched to physical parameters as follows: R1 stands for the resistivity of the outer elements and electrodes connections. R2 results from the conductivity of the doped or undoped LC material and is caused by the mobility

• [24], generating a hybrid structure that follows the electric field, but does not relax as the restoring elastic forces cannot compete with nanometer-sized structures. This idea is supported by the fact that the high resistivity of the original state is not restored even by heating the sample above

Materials and characterization techniques for high-temperature polymer electrolyte membrane fuel cells

• Roswitha Zeis

Beilstein J. Nanotechnol. 2015, 6, 68–83, doi:10.3762/bjnano.6.8

• potentials leads to severe corrosion of theses carbon materials, a drawback well-known from the PAFC research. Carbon nanotubes are a promising alternative for catalyst support because of their higher corrosion resistivity [47]. Matsumoto et al. [48] fabricated a catalyst material by wrapping individual

Formation of stable Si–O–C submonolayers on hydrogen-terminated silicon(111) under low-temperature conditions

• Yit Lung Khung,
• Siti Hawa Ngalim,
• Andrea Scaccabarozzi and
• Dario Narducci

Beilstein J. Nanotechnol. 2015, 6, 19–26, doi:10.3762/bjnano.6.3

• . Experimental Materials Silicon wafers (111), were boron-doped (resistivity of 0.01–0.018 Ω·cm) and were used in this experiment. Sulfuric acid (Aldrich) and hydrogen peroxide (BDH Prolabo) were of semiconductor grade. 4-ethynylbenzyl alcohol and 4-ethynyl-α,α,α-trifluorotoluene were purchased from Sigma

Exploring plasmonic coupling in hole-cap arrays

• Thomas M. Schmidt,
• Maj Frederiksen,
• Vladimir Bochenkov and
• Duncan S. Sutherland

Beilstein J. Nanotechnol. 2015, 6, 1–10, doi:10.3762/bjnano.6.1

• sulfate latex polystyrene particles with diameter of 0.11 µm were obtained from Invitrogen Denmark. Deionized water with 18.2 MΩ resistivity from a Millipore Milli-Q water system. Poly(methyl methacrylate) (PMMA) (Mw 120,000), Polystyrene (Mw 280,000), PDDA (poly(diallydimethylammonium chloride)) (Mw

Low cost, p-ZnO/n-Si, rectifying, nano heterojunction diode: Fabrication and electrical characterization

• Vinay Kabra,
• Lubna Aamir and
• M. M. Malik

Beilstein J. Nanotechnol. 2014, 5, 2216–2221, doi:10.3762/bjnano.5.230

• . Hall effect measurement The Hall effect measurement of a p-ZnO rectangular pellet with dimensions 0.8 × 0.8 × 0.1 cm3 was performed using a four-probe van der Pauw method using silver contacts, and data were averaged to ensure accuracy. The carrier concentration, Hall mobility and resistivity of p-ZnO

• values of the carrier concentration, Hall mobility and resistivity of Si substrate were found to be 2.3 × 1015 cm−3, 555 cm2/Vs, and 5 Ωcm, respectively. It is apparent that the carrier concentration, mobility and resistivity of these p-ZnO nanoparticles are sufficient for use in the fabrication of a

Electrical contacts to individual SWCNTs: A review

• Wei Liu,
• Christofer Hierold and
• Miroslav Haluska

Beilstein J. Nanotechnol. 2014, 5, 2202–2215, doi:10.3762/bjnano.5.229

• = h/4e2, rch is the channel resistance per unit length, Rc is the single contact resistance, ρc is the specific contact resistivity, Lc and Lch represent the contact width and the channel length, respectively, d is the diameter of the SWCNT, and Le is the mean free path for carrier scattering (which

Properties of plasmonic arrays produced by pulsed-laser nanostructuring of thin Au films

• Katarzyna Grochowska,
• Katarzyna Siuzdak,
• Peter A. Atanasov,
• Carla Bittencourt,
• Anna Dikovska,
• Nikolay N. Nedyalkov and
• Gerard Śliwiński

Beilstein J. Nanotechnol. 2014, 5, 2102–2112, doi:10.3762/bjnano.5.219

• surface plasmon resonance (SPR) peak around 520 nm resulted in the observable decrease of the film roughness and resistivity [14]. In case of nanostructuring of a thin Au film by a pulsed-laser beam passing through a pinhole (60 μm), the forced arrangement of nanospheres into micro-circular patterns due

Photodetectors based on carbon nanotubes deposited by using a spray technique on semi-insulating gallium arsenide

• Domenico Melisi,
• Maria Angela Nitti,
• Marco Valentini,
• Antonio Valentini,
• Teresa Ligonzo,
• Giuseppe De Pascali and
• Marianna Ambrico

Beilstein J. Nanotechnol. 2014, 5, 1999–2006, doi:10.3762/bjnano.5.208

• ), custom-made transparent Mylar masks were used to better confine the CNT deposition area. SI GaAs substrates (350 ± 25 μm, resistivity 5.4·107–9.1·107 Ω·cm, Hall mobility 5692–6025 cm2·V−1·s−1, carrier concentration 1.2·107–2.1·107 cm−3), produced by Wafer Technology LTD, were used for the fabrication of

High speed e-beam lithography for gold nanoarray fabrication and use in nanotechnology

• Jorge Trasobares,
• François Vaurette,
• Marc François,
• Hans Romijn,
• Jean-Louis Codron,
• Dominique Vuillaume,
• Didier Théron and
• Nicolas Clément

Beilstein J. Nanotechnol. 2014, 5, 1918–1925, doi:10.3762/bjnano.5.202

• use an EBPG 5000 Plus from Vistec Lithography. The (100) Si substrate (resistivity = 10−3 Ω·cm) is cleaned with UV/ozone and native oxide etched before resist deposition. The e-beam lithography has been optimized by using a 45 nm-thick diluted (3:5 with anisole) PMMA (950 K). For the writing, we use

Experimental techniques for the characterization of carbon nanoparticles – a brief overview

• Wojciech Kempiński,
• Szymon Łoś,
• Mateusz Kempiński and
• Damian Markowski

Beilstein J. Nanotechnol. 2014, 5, 1760–1766, doi:10.3762/bjnano.5.186

• carrier transport within the systems of CNs by varying the temperature, adsorbed molecules and external electric field. Due to the significant changes in resistivity induced by the host–guest interactions, the systems of CNs might prove interesting in the fields of gas sensing, molecular electronics or

• energy allowing the hopping of charge carriers between the CNs [4][37]. Hopping charge carrier transport in the granular structures is described with the CGVRH model [4], from which the following equation has been derived: where ρ stands for the resistivity, ρ0 is a temperature-independent constant, T is

• paramagnetic systems with the fixed number of spins (Langevin paramagnetism) [36]. In the case of the ACFs, the number of spins observed in EPR changes according to Equation 1. This is related to the CGVRH model, where resistivity depends on the temperature. In the classical approach [37] the resistivity ρ

Growth evolution and phase transition from chalcocite to digenite in nanocrystalline copper sulfide: Morphological, optical and electrical properties

• Priscilla Vasthi Quintana-Ramirez,
• Ma. Concepción Arenas-Arrocena,
• José Santos-Cruz,
• Marina Vega-González,
• Omar Martínez-Alvarez,
• Víctor Manuel Castaño-Meneses,
• Laura Susana Acosta-Torres and
• Javier de la Fuente-Hernández

Beilstein J. Nanotechnol. 2014, 5, 1542–1552, doi:10.3762/bjnano.5.166

• , optical, and morphological properties of the copper sulfide. In fact, digenite Cu1.8S is less resistive (346 Ω/sq) and has a lower energy band gap (1.6 eV) than chalcocite Cu2S (5.72 × 105 Ω/sq, 1.87 eV). Low resistivity was also obtained in CuxS synthesized in aqueous solution, despite its amorphous

• ]. Electrical properties The CuxS films prepared in aqueous solution are amorphous with undefined morphology. They exhibit a low square electrical resistivity (about 103 Ω/sq) as shown in Figure 6. Chalcocite CuxS from organic solution has a resistance of the order of 105–106 Ω/sq, while crystalline CuxS has a

• resistivity of about 107 Ω/sq at 240 °C and 102 Ω/sq at 260 °C, respectively. In fact, the samples obtained at 230 and 240 °C, which consist of a mixture of chalcocite and digenite phases, are more resistive than the digenite phase (sample at 260 °C). This means that the copper deficiency improves the

Probing the electronic transport on the reconstructed Au/Ge(001) surface

• Franciszek Krok,
• Mark R. Kaspers,
• Alexander M. Bernhart,
• Marek Nikiel,
• Benedykt R. Jany,
• Paulina Indyka,
• Mateusz Wojtaszek,
• Rolf Möller and
• Christian A. Bobisch

Beilstein J. Nanotechnol. 2014, 5, 1463–1471, doi:10.3762/bjnano.5.159

• the domain boundaries. Experimental The germanium substrate is cut from a wafer of a n-type Ge(001) crystal with a resistivity of about 30 Ω·cm. The cleaning procedure of the substrate consists of a few cycles of 600 eV Ar+ ion sputtering at a sample temperature of 1040 K (as measured by a pyrometer

• rather flat and smooth, only limited by the resolution of our STP setup (±5 µV) and is constant within the experimental error. At the edge of the Au clusters a discontinuity of the potential occurs. The resistivity, i.e., the corresponding gradient of the potential on the terraces scales about linearly

• easily recognized. e) and f) show the topography and the corresponding potential for a small area near a step edge, i.e., domain boundary. The directions of the atomic wires are marked by white lines in a) and e) (Vbat = 9 V, Itrans = 3 mA). Resistivity, as evaluated from the gradient of the potential in

Review of nanostructured devices for thermoelectric applications

• Giovanni Pennelli

Beilstein J. Nanotechnol. 2014, 5, 1268–1284, doi:10.3762/bjnano.5.141

• electrical resistivity ρ = 1/σ and from the material thermal conductivity kt, to be combined with the geometrical parameters of the legs (length and cross-section surface). Given a temperature difference TH − TC, the generator acts as a voltage generator with an open circuit voltage Vg = Stotal(TH − TC

Purification of ethanol for highly sensitive self-assembly experiments

• Kathrin Barbe,
• Martin Kind,
• Christian Pfeiffer and
• Andreas Terfort

Beilstein J. Nanotechnol. 2014, 5, 1254–1260, doi:10.3762/bjnano.5.139

• long exposure times, it has been found that for kinetic studies even very minor contaminations can significantly affect the measurements [29]. Of the different time-resolved methods to determine monolayer formation, surface-plasmon resonance (SPR) [30][31] and a resistivity sensor developed by Bohn et

• material advantageously becomes regenerated at 723 K without any loss of thiol adsorption capacity. With this material at hand, we set out to purify ethanol to become suitable for kinetic measurements. As an assay, we used the sensoric principle developed by Bohn et al. [29][32], based on the resistivity

• change of thin gold films upon chemisorption of molecular films. For a selected class of compounds, such as alkanethiols, a very good linear correlation between the increase of resistivity and the surface coverage Θ has been established [29][32]. As an initial test, several commercial qualities of

Direct nanoscale observations of the coupled dissolution of calcite and dolomite and the precipitation of gypsum

• Francesco G. Offeddu,
• Jordi Cama,
• Josep M. Soler and
• Christine V. Putnis

Beilstein J. Nanotechnol. 2014, 5, 1245–1253, doi:10.3762/bjnano.5.138

• the (104) surface. Acid solutions were prepared immediately before the experiments by adding the appropriate amounts of reactive analytical grade, CaSO4·2H2O (Merck pro analysis) and Na2SO4 (Grüssing purity 98%), to Millipore MQ water (resistivity = 18 MΩ·cm) (Table 1). The solution pH was adjusted to

Organic and inorganic–organic thin film structures by molecular layer deposition: A review

• Pia Sundberg and
• Maarit Karppinen

Beilstein J. Nanotechnol. 2014, 5, 1104–1136, doi:10.3762/bjnano.5.123

Highly NO₂ sensitive caesium doped graphene oxide conductometric sensors

• Carlo Piloto,
• Marco Notarianni,
• Mahnaz Shafiei,
• Elena Taran,
• Dilini Galpaya,
• Cheng Yan and
• Nunzio Motta

Beilstein J. Nanotechnol. 2014, 5, 1073–1081, doi:10.3762/bjnano.5.120

• equation: where Rair is the sensing film resistance under synthetic air only and Rgas is the film resistance during NO2 exposure. As expected, the GO film showed a much higher resistivity than the GO-Cs film in the presence of air (1013 Ω vs 1010 Ω). The lower baseline resistance can be attributed to the

• NO2, ranging from 0.090 to 12.2 ppm. Both sensors exhibited a reduction in resistivity upon exposure to the gas, in agreement with the theory developed by Tang and Cao [14]: a negative charge is transferred to the NO2 molecules, mostly in correspondence of oxygen functional group, resulting in a p

• GO response is initially higher than GO-Cs, but decreases more rapidly. When exposed to 1.5 ppm, GO response is not anymore appreciable while a GO-Cs reaction is still evident. The noisier curves of GO is due to its higher resistivity value. Both sensors exhibit a long time to recover their initial

Pyrite nanoparticles as a Fenton-like reagent for in situ remediation of organic pollutants

• Carolina Gil-Lozano,
• Elisabeth Losa-Adams,
• Alfonso F.-Dávila and
• Luis Gago-Duport

Beilstein J. Nanotechnol. 2014, 5, 855–864, doi:10.3762/bjnano.5.97

• Aldrich. Ferrous chloride tetrahydrate (FeCl2·4H2O, 99%) was purchased from Fluka. Absolute ethanol was purchased from Quimivita. All chemicals were used as received without any further purification. Aqueous suspensions of pyrite were prepared using deionized water (resistivity: ca. 18 MΩ·cm) purified in

Towards precise defect control in layered oxide structures by using oxide molecular beam epitaxy

• Federico Baiutti,
• Georg Christiani and
• Gennady Logvenov

Beilstein J. Nanotechnol. 2014, 5, 596–602, doi:10.3762/bjnano.5.70

• superconducting La2CuO4+δ, with Tc ≈ 40 K, upon annealing in ozone atmosphere due to the introduction of interstitial oxygen [23]. In Figure 6, we present resistivity versus temperature curves for two La2CuO4 films grown in our lab, carried out by using a four-probe method with Pt contacts deposited by sputtering

• cooling rate of 30 °C/min and then the ozone delivery was stopped and the film was cooled down to room temperature in vacuum (10−9 Torr), and shows a resistivity curve that is an exponential function of temperature, while the second one, cooled down to room temperature at an increased ozone pressure of 5

• report the calculated c-axis values for the different grown compositions: they exhibit a monotonical decrease for increasing doping content. The in-plane resistivity versus temperature for La2−xSrxNiO4 with different Sr doping level is shown in Figure 8. The resistivity value systematically decreases

Preparation of poly(N-vinylpyrrolidone)-stabilized ZnO colloid nanoparticles

• Tatyana Gutul,
• Emil Rusu,
• Nadejda Condur,
• Veaceslav Ursaki,
• Evgenii Goncearenco and
• Paulina Vlazan

Beilstein J. Nanotechnol. 2014, 5, 402–406, doi:10.3762/bjnano.5.47

• photoluminescence intensity was increased because of the passivation of surface defects in the nanoparticles [7]. Nanohybrid films with resistivity of 108 Ω·cm were obtained by using PVP with molar mass of 400,000 at various Zn2+/PVP ratios [8]. Colloidal solutions of ZnO are obtained by different methods. For

Tensile properties of a boron/nitrogen-doped carbon nanotube–graphene hybrid structure

• Kang Xia,
• Haifei Zhan,
• Ye Wei and
• Yuantong Gu

Beilstein J. Nanotechnol. 2014, 5, 329–336, doi:10.3762/bjnano.5.37

• ferroelectric properties and the layer resistivity, N and B doping is widely adopted in thin films studies [31][32][33][34]. In this section, we consider a hybrid structure that is doped with both nitrogen and boron. The stress–strain curve is presented in Figure 7. As can be seen, GNHS-0.25%N0.25%B has similar

En route to controlled catalytic CVD synthesis of densely packed and vertically aligned nitrogen-doped carbon nanotube arrays

• Slawomir Boncel,
• Sebastian W. Pattinson,
• Valérie Geiser,
• Milo S. P. Shaffer and
• Krzysztof K. K. Koziol

Beilstein J. Nanotechnol. 2014, 5, 219–233, doi:10.3762/bjnano.5.24

• of reactivity centres (‘hot-spots’) that are more susceptible to thermal cleavage and attack of oxygen. The higher number of ‘nanogrooves’, which translates into a higher surface area, could additionally enhance the accessibility of the outer nanotube walls. Moreover, the thermal resistivity in air

Charge and spin transport in mesoscopic superconductors

• M. J. Wolf,
• F. Hübler,
• S. Kolenda and
• D. Beckmann

Beilstein J. Nanotechnol. 2014, 5, 180–185, doi:10.3762/bjnano.5.18

• is where is the derivative of the Fermi function, ρN is the normal-state resistivity of the superconductor, and is the cross-section area of the superconducting wire. In Figure 2, we compare the model predictions to the experimental data. We proceeded by first fitting at finite magnetic fields

• dotted lines in Figure 2b. As can be seen, a good fit can be made for the initial slope of the data, and we obtain DN = 70 cm2/s from the fit, a value somewhat larger than the independent estimate (40 cm2/s) from the resistivity. Without additional fitting, we can then plot the predictions for the

Photovoltaic properties of ZnO nanorods/p-type Si heterojunction structures

• Rafal Pietruszka,
• Bartlomiej S. Witkowski,
• Grzegorz Luka,
• Lukasz Wachnicki,
• Sylwia Gieraltowska,
• Krzysztof Kopalko,
• Eunika Zielony,
• Piotr Bieganski,
• Ewa Placzek-Popko and
• Marek Godlewski

Beilstein J. Nanotechnol. 2014, 5, 173–179, doi:10.3762/bjnano.5.17

• used to store data for a long period of time [21]. In PV structures, ZnO can replace the commonly used indium tin oxide (ITO) as a transparent electrode. Thin films of ZnO doped with aluminum (ZnO:Al, AZO) or gallium (ZnO:Ga, GZO) obtained by various deposition methods, show a resistivity of the order

• aluminum precursor. The growth temperature was 160 °C and the N2 was used as a purging gas. To obtain a high conductivity of the ZnO film, we mixed ALD cycles. We applied 1 cycle TMA + H2O and 24 cycles of DEZ + H2O to obtain a uniform distribution of Al in the layer. The lowest resistivity was achieved

In situ growth optimization in focused electron-beam induced deposition

• Paul M. Weirich,
• Marcel Winhold,
• Christian H. Schwalb and
• Michael Huth

Beilstein J. Nanotechnol. 2013, 4, 919–926, doi:10.3762/bjnano.4.103

• sample 2 to sample 3, whereas the oxygen content is reduced. The corresponding resistivity of the different samples was calculated from the conductance measurements in Figure 3b in combination with AFM measurements of the deposits. As already indicated by the result of the EDX measurements the

• resistivity of the tungsten deposits is reduced by one order of magnitude for the optimized GA parameters compared to the GA parameters for lowest conductance. The results for the GA optimization for the W(CO)6 deposits are summarized in Table 1. Discussion For the thus far presented case of W(CO)6, the great

• small Pt-crystallites between existing Pt-crystals in the nanogranular structure of Pt–C or to a growth of the previously present Pt-crystallites that leads to a reduction of the intergrain distance and therefore to a decreasing resistivity [33]. We found that, as already shown in previous experiments