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

• starting material. The morphological properties of the deposited films has been analysed by means of electron microscopy, in scanning and transmission mode. Detectors with different layouts have been prepared and current–voltage characteristics have been recorded in the dark and under irradiation with

• , electron microscopy, in scanning (SEM) and transmission (TEM) modes, was used. Current–voltage (I–V) characterizations under dark and illuminated conditions, from NIR to UV region, were performed with two different device configurations. The resulting QE and the photocurrent spectral measurements are

• Detectors, serial no. 97-527) was used for the QE calculation. An Agilent source/monitor unit was used to record the current–voltage characteristics. To obtain more detailed information of the photodetector in the range of vis–NIR, photocurrent spectra of the SFS and of the ITO/GaAs/Ti/Au control sample

The influence of molecular mobility on the properties of networks of gold nanoparticles and organic ligands

• Edwin J. Devid,
• Paulo N. Martinho,
• M. Venkata Kamalakar,
• Úna Prendergast,
• Christian Kübel,
• Tibebe Lemma,
• Jean-François Dayen,
• Tia. E. Keyes,
• Bernard Doudin,
• Mario Ruben and
• Sense Jan van der Molen

Beilstein J. Nanotechnol. 2014, 5, 1664–1674, doi:10.3762/bjnano.5.177

• estimated typical Coulomb-blockade charging energies of around 14–17 meV [5], in correspondence with temperature- and voltage-dependent transport measurements. Hence, in alkanethiol and OPE-based networks Coulomb blockade dominates below 200–250 K, whereas around room temperature, the current–voltage (I–V

• current–voltage (I–V) curves of Au-NP–S-BPP networks). If we compare octanethiol and OPE-based networks with the Au-NP–S-BPP network, the latter behaves differently at higher temperatures. For example, for the first two types of samples, the low-bias resistance is basically independent of voltage and

An analytical approach to evaluate the performance of graphene and carbon nanotubes for NH₃ gas sensor applications

• Elnaz Akbari,
• Vijay K. Arora,
• Aria Enzevaee,
• Mohamad. T. Ahmadi,
• Mehdi Saeidmanesh,
• Mohsen Khaledian,
• Hediyeh Karimi and
• Rubiyah Yusof

Beilstein J. Nanotechnol. 2014, 5, 726–734, doi:10.3762/bjnano.5.85

• surface molecules is emphasized. NH3 has been used as the prototype gas to be detected by the nanosensor and the corresponding current–voltage (I–V) characteristics of the FET-based sensor are studied. A graphene-based gas sensor model is also developed. The results from graphene and CNT models are

• Fermi–Dirac integral can be obtained from Equation 12 as . Accordingly, the Fermi–Dirac integral of order –1/2 can be simplified as [50]: Based on the current–voltage characteristic of graphene-based FET devices, the gas sensor performance can be evaluated through Equation 14. Assuming that the source

• : Results and Discussion Figure 4 illustrates the assessments of the gas sensor performance based on CNT and graphene nano-structures by considering their current–voltage characteristics when they are exposed to NH3 [53]. Also shown is the experimental data [53]. The agreement is good except near the

An ultrasonic technology for production of antibacterial nanomaterials and their coating on textiles

• Anna V. Abramova,
• Vladimir O. Abramov,
• Aharon Gedanken,
• Ilana Perelshtein and
• Vadim M. Bayazitov

Beilstein J. Nanotechnol. 2014, 5, 532–536, doi:10.3762/bjnano.5.62

• bubbly liquid between the electrodes. The experiments also revealed that the sonoplasma discharge is characterized by a glow in the whole volume of the liquid and an increasing current–voltage characteristic, which is typical for the abnormal glow discharge. Arc discharges in aqueous electrolytes, which

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

• solar cell structures were characterized by a Scanning Electron Microscope Hitachi SU-70 with an accelerating voltage of 15 kV. PV response was measured by using current–voltage (I–V) curve tracer for fast I–V measurements with a sun simulator cl. AAA, at an illumination irradiance of 100 mW/cm2

• investigated solar cells structure based on zinc oxide nanorods (not to scale). Cross-section and top view (up) SEM images illustrating zinc oxide nanorods grown at different pH values of 7, 7.5 and 8. Images at the bottom show cross-section and top view of ZnONR covered with ZnO:Al layers. Current–voltage

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

• 10–6 Torr. The used experimental set-up allows the registration of FE current–voltage dependencies and the distribution of emission sites over the cathode surface in direct current and pulsed regimes corresponding to the device applications. The CL lamp manufacturing was made with the use of standard

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

• dramatically reduced microphysical changes after electrical operation. Keywords: electron microscopy; memristor; resistance switching; transition-metal oxide; X-ray spectroscopy; Introduction A memristor is a passive electronic element that displays a pinched hysteresis loop in its current–voltage

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

• rectangular graphene area. The current–voltage (I–V) characteristics for different distances between adjacent contacts are reported in Figure 4b, showing an Ohmic behaviour for all the contact distances. In Figure 4c the resistance R, obtained from the slope of each curve, is plotted versus the contact

• method. The contacts had identical geometry (200 µm width and 100 µm length) and the distance between the pairs of adjacent contacts were 20, 20, 40, 60, 80, 100 and 100 µm, respectively. The current–voltage (I–V) characteristics were measured in a Karl-Süss probe station by using a HP 4156B parameter

Photoresponse from single upright-standing ZnO nanorods explored by photoconductive AFM

• Igor Beinik,
• Markus Kratzer,
• Astrid Wachauer,
• Lin Wang,
• Yuri P. Piryatinski,
• Gerhard Brauer,
• Xin Yi Chen,
• Yuk Fan Hsu,
• Aleksandra B. Djurišić and
• Christian Teichert

Beilstein J. Nanotechnol. 2013, 4, 208–217, doi:10.3762/bjnano.4.21

• were carried out under ambient conditions on as-grown samples. The current–voltage (I–V) characteristics were recorded at the sample surface, which was under illumination directly from the optical fiber placed at an angle of about 15 to 20° with respect to the surface. For these measurements, we used a

• upright standing ZnO nanorods, of photoluminescence obtained at 300 K. Current–voltage characteristics of dark (green curve, dashed) and illuminated state (red curve, solid) recorded from a single upright-standing ZnO nanorod by using a standard ±20 nA range amplifier. The illuminated characteristic was

Influence of diffusion on space-charge-limited current measurements in organic semiconductors

• Thomas Kirchartz

Beilstein J. Nanotechnol. 2013, 4, 180–188, doi:10.3762/bjnano.4.18

• Thomas Kirchartz Department of Physics and Centre for Plastic Electronics, Imperial College London, South Kensington Campus SW7 2AZ, United Kingdom 10.3762/bjnano.4.18 Abstract Numerical simulations of current–voltage curves in electron-only devices are used to discuss the influence of charged

• reasonably accurate mobility values. Keywords: current–voltage curves; electron-only device; drift–diffusion; mobility; simulation; traps; Introduction A frequently used method to analyze charge carrier transport in organic semiconductors is based on space-charge-limited current measurements performed on

• single carrier devices [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. These devices consist of two contacts that are either both electron-injecting or both hole-injecting, meaning that the current–voltage curve of these devices is not determined by the recombination of electrons and holes in the volume

Sub-10 nm colloidal lithography for circuit-integrated spin-photo-electronic devices

• Adrian Iovan,
• Marco Fischer,
• Roberto Lo Conte and
• Vladislav Korenivski

Beilstein J. Nanotechnol. 2012, 3, 884–892, doi:10.3762/bjnano.3.98

• effects due to spin-flip relaxation are expected, only phonon relaxation (heat). The typical array resistance is measured to be 10–20 mΩ. The current–voltage characteristic is smooth and approximately parabolic, typical of the expected phonon background. Thus, these test data agreed with the expected

• -type changes in the current–voltage characteristics of our fully enclosed optical resonator. Such threshold-type excitations, of giant magnitude, are indeed observed in the device resistance (conductance changes of a factor of 2), as shown in Figure 5c. This demonstration opens the way to explore a new

• 40 nm thick SiO2 layer for insulation, rotating the sample holder during deposition. Finally, the resist was lifted off, and the last step of lithography was the use of negative resist and deposition of a 200 nm thick Al top electrode. Transport measurements: The current–voltage (I–V) characteristics

Current–voltage characteristics of single-molecule diarylethene junctions measured with adjustable gold electrodes in solution

• Bernd M. Briechle,
• Youngsang Kim,
• Philipp Ehrenreich,
• Artur Erbe,
• Dmytro Sysoiev,
• Thomas Huhn,
• Ulrich Groth and
• Elke Scheer

Beilstein J. Nanotechnol. 2012, 3, 798–808, doi:10.3762/bjnano.3.89

• current–voltage characteristics of these junctions are measured in a mechanically controlled break-junction system at room temperature and in liquid environment. We compare the transport properties of a series of molecules, labeled TSC, MN, and 4Py, with the same switching core but varying side-arms and

• [30][31]. Recently, low-temperature measurements of the current–voltage characteristics of single-molecule diarylethene junctions have been reported [32]. By applying the resonant-level model, the level alignment and the coupling strength of the dominant current-carrying molecular orbital (frontier

• several thousands of traces are used. A more detailed discussion about the histograms and the stability of individual junctions is given in Supporting Information File 1. For recording the current–voltage (I–V) characteristics the breaking procedure can be stopped at any position of the stretching or

The memory effect of nanoscale memristors investigated by conducting scanning probe microscopy methods

• César Moreno,
• Carmen Munuera,
• Xavier Obradors and
• Carmen Ocal

Beilstein J. Nanotechnol. 2012, 3, 722–730, doi:10.3762/bjnano.3.82

• ] and therefore the characterization of the local electrical properties becomes more and more important. In this work we have combined conductive scanning force microscopy imaging and single-point current–voltage spectroscopy, with more advanced spectroscopy measurements (3-D modes) to characterize the

• , interpretation of colour-coded current maps depends on the voltage sign as well as the absolute current magnitude. Thus higher currents appear darker in C-SFM images taken at negative Vtip, while brighter for positive Vtip. The current–voltage (I–V) characteristics of the contact were measured as a function of

Revealing thermal effects in the electronic transport through irradiated atomic metal point contacts

• Bastian Kopp,
• Zhiwei Yi,
• Daniel Benner,
• Fang-Qing Xie,
• Christian Obermair,
• Thomas Schimmel,
• Johannes Boneberg,
• Paul Leiderer and
• Elke Scheer

Beilstein J. Nanotechnol. 2012, 3, 703–711, doi:10.3762/bjnano.3.80

• electrode is controlled by the virtual ground technique implemented by the operational amplifier (OP2) in this current–voltage converter. The size of the atomic contact is controlled by applying the control potential Uec through amplifier OP1. The whole measurement is controlled by a home-written software

Low-temperature synthesis of carbon nanotubes on indium tin oxide electrodes for organic solar cells

• Andrea Capasso,
• Luigi Salamandra,
• Aldo Di Carlo,
• John M. Bell and
• Nunzio Motta

Beilstein J. Nanotechnol. 2012, 3, 524–532, doi:10.3762/bjnano.3.60

• with bare ITO-coated glass were also made for comparison with the same procedure. The current–voltage (I–V) characteristics under 1 sun (AM1.5G) were measured with an Agilent E5262A source meter. SEM images of MWCNTs grown on ITO-coated glass by CVD at: (a) 550 °C, (b) 525 °C, (c) 500 °C. Transmittance

• 525 °C). WF levels for cells with ITO (left) and ITO–CNT (right) electrode. (All reported values are in eV and negative). Current–voltage characteristic and output power of P3HT:PCBM solar cells: (a) Cell C and cell C1, compared to a reference cell made with bare ITO-coated glass; (b) classic ITO

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

• compare the current–voltage curves collected. As reported in Figure 10a and Figure 10b, the open-circuit voltage (Voc) and the short-circuit density current (Jsc) in the in-plane configuration are markedly lower than those collected in the top-down geometry. The lower value of Jsc can be justified by the

Ultraviolet photodetection of flexible ZnO nanowire sheets in polydimethylsiloxane polymer

• Jinzhang Liu,
• Nunzio Motta and
• Soonil Lee

Beilstein J. Nanotechnol. 2012, 3, 353–359, doi:10.3762/bjnano.3.41

• PDMS would slowly spread out of the agglomeration of Ag nanoparticles and infiltrate the nanowire film due to capillarity. Figure 3a shows the current–voltage (I–V) curves of the device in PDMS, measured under UV-light illumination (312 nm, 30 mW·cm−2) and in the dark. The I–V curves of two other

Current-induced dynamics in carbon atomic contacts

• Jing-Tao Lü,
• Tue Gunst,
• Per Hedegård and
• Mads Brandbyge

Beilstein J. Nanotechnol. 2011, 2, 814–823, doi:10.3762/bjnano.2.90

• applied between the two electrodes, Vb. We will show that this offers a convenient way to explore current-induced vibrational instabilities. We can already see the effect of the gate potential in the current–voltage (I − Vb) characteristics shown in Figure 2. The effect of the NC and BP forces is to

• perpendicular to the graphene surface. The center panel shows the calculated contour plot of the electrostatic-potential drop across the junction at Vg = 0 V, and Vb = 1 V. The equal drop at the left and right electrodes reflects the electron–hole symmetry for Vg = 0 V [40]. Current–Voltage (I−Vb) curves at

Nonconservative current-induced forces: A physical interpretation

• Tchavdar N. Todorov,
• Daniel Dundas,
• Anthony T. Paxton and
• Andrew P. Horsfield

Beilstein J. Nanotechnol. 2011, 2, 727–733, doi:10.3762/bjnano.2.79

• –electron interactions, determine the current–voltage spectrum of the system. Allowing nuclei to respond to current-induced forces introduces two additional elements: Current-driven displacements and Joule heating. Current-induced forces arise, fundamentally, through momentum transfer from the electron flow

Charge transport in a zinc–porphyrin single-molecule junction

• Mickael L. Perrin,
• Christian A. Martin,
• Ferry Prins,
• Ahson J. Shaikh,
• Rienk Eelkema,
• Jan H. van Esch,
• Jan M. van Ruitenbeek,
• Herre S. J. van der Zant and
• Diana Dulić

Beilstein J. Nanotechnol. 2011, 2, 714–719, doi:10.3762/bjnano.2.77

• allows us to characterize the transport in a molecular junction in detail. This complex molecule can form different junction configurations, having an observable effect on the trace histograms and the current–voltage (I(V)) measurements. Both methods show that multiple, stable single-molecule junction

• (MCBJ) technique, we study the low-bias conductance as a function of the electrode displacement. In addition, we perform current–voltage measurements at different electrode spacings in order to gain spectroscopic information in the high-bias regime. The MCBJ technique is an elegant way to control the

• low-bias conductance of the molecule as a function of the electrode stretching. Second, we perform spectroscopy of the molecular energy levels by measuring current–voltage characteristics at fixed electrode spacings; this was done both at room temperature and cryogenic temperature (6 K). Results To

An MCBJ case study: The influence of π-conjugation on the single-molecule conductance at a solid/liquid interface

• Wenjing Hong,
• Hennie Valkenier,
• Gábor Mészáros,
• David Zsolt Manrique,
• Artem Mishchenko,
• Alexander Putz,
• Pavel Moreno García,
• Colin J. Lambert,
• Jan C. Hummelen and
• Thomas Wandlowski

Beilstein J. Nanotechnol. 2011, 2, 699–713, doi:10.3762/bjnano.2.76

• current–distance and current–voltage measurements revealed details of the influence of π-conjugation on the single-molecule conductance. Keywords: anthraquinone; π-conjugation; mechanically controlled break junction; single-molecule conductance; Introduction Molecular electronics has expanded

• ), and a dihydroanthracene-based wire with a broken π-conjugation (AH) (Figure 1). The transport characteristics in single molecular junctions were investigated by conductance–distance as well as continuous current–voltage measurements in complementary MCBJ and STM-BJ experiments. In particular, a custom

• same analysis method to the blue traces did not lead to any clear feature between 10−1 G0 and 10−8 G0, which supports the assignment of the two types of traces. Continuous current–voltage (I–V) measurement I–V curves in the stretching process The high mechanical stability of the MCBJ setup provides a

Charge transfer through single molecule contacts: How reliable are rate descriptions?

• Denis Kast,
• L. Kecke and
• J. Ankerhold

Beilstein J. Nanotechnol. 2011, 2, 416–426, doi:10.3762/bjnano.2.47

• molecule, i.e., with Single charge tunneling through the device can be formally and exactly captured under weak conditions (e.g., instantaneous equilibration in the leads during charge transfer) within the Meir–Wingreen formulation based on nonequilibrium Green’s functions [14][15]. For the current

• –voltage characteristics one finds with energy dependent lead self-energies ∑α(ε) = 2π∑k|Tk,α|2δ(ε – εk) and with the Fourier transforms of the time dependent Green’s functions and . Upon applying the polaron transformation (Equation 2), one has where all expectation values are calculated with the full