Thermoelectricity in molecular junctions with harmonic and anharmonic modes

• Bijay Kumar Agarwalla,
• Jian-Hua Jiang and
• Dvira Segal

Beilstein J. Nanotechnol. 2015, 6, 2129–2139, doi:10.3762/bjnano.6.218

• Figure 6 we simulate the current–voltage characteristics and the resulting efficiency of the D–A junction beyond linear response, by directly applying Equation 13. As discussed in previous investigations [6][7][8], the molecular junction may break down far from equilibrium due to the development of

• plot of linear response efficiencies as a function of hybridization Γ and electronic energies (or gate voltage) ε0. (a) Maximum efficiency. (b) Efficiency at maximum power. Parameters are ω0 = 0.02 eV and T = 300 K. Transport beyond linear response. (a) current voltage characteristics for the harmonic

Materials for sustainable energy production, storage, and conversion

• Maximilian Fichtner

Beilstein J. Nanotechnol. 2015, 6, 1601–1602, doi:10.3762/bjnano.6.163

• present recent results from the respective working groups. In the field of energy harvesting and photovoltaics, Benedikt Iffland and Christian Jooss [1] report on current–voltage characteristics of manganite–titanite perovskite junctions. State-of-the art and recent progress in energy conversion from

Electrical properties and mechanical stability of anchoring groups for single-molecule electronics

• Riccardo Frisenda,
• Simge Tarkuç,
• Elena Galán,
• Mickael L. Perrin,
• Rienk Eelkema,
• Ferdinand C. Grozema and
• Herre S. J. van der Zant

Beilstein J. Nanotechnol. 2015, 6, 1558–1567, doi:10.3762/bjnano.6.159

• combined characterization of the electrical and mechanical properties determined by the anchoring groups. From conductance histograms we find that thiol anchored molecules provide the highest conductance; a single-level model fit to current–voltage characteristics suggests that SAc groups exhibit a higher

• , in order to explore how the nature of the molecule–electrode contact influences the conductance measurements. The electrical properties were studied by measuring the conductance and current–voltage characteristics as a function of electrode distance. A statistical analysis of the I–Vs with a fit to a

• , with G0 = 2e2/h being the quantum of conductance. Typically, we measured more than 2000 individual conductance-distance breaking traces for each molecule; these traces are used to construct the one- and two-dimensional histograms. To measure current–voltage characteristics of single-molecule junctions

Current–voltage characteristics of manganite–titanite perovskite junctions

• Benedikt Ifland,
• Patrick Peretzki,
• Birte Kressdorf,
• Philipp Saring,
• Andreas Kelling,
• Michael Seibt and
• Christian Jooss

Beilstein J. Nanotechnol. 2015, 6, 1467–1484, doi:10.3762/bjnano.6.152

• electron–polaron hole–polaron pair generation and separation at the interface. Keywords: current–voltage characteristics; perovskites; photovoltaics; polarons; Introduction At present, photovoltaic devices are mainly based on high purity elemental or compound inorganic semiconducting materials with large

• , IEBIC,S+L. This leads to a combined diffusion length, LPCMO + LSTNO = 21.4(2) nm. The noticeable asymmetry in the experimental EBIC linescan indicates that a larger part of the combined diffusion length can be attributed to LSTNO. Current–voltage characteristics without illumination The measured current

• –voltage characteristics of the analyzed manganite–titanate junction are summarized in Figure 4, where J is the current density. For all measurements at different temperatures, the rectifying characteristic of the junction can be recognized. By decreasing the temperature, a plateau evolves for the reverse

Can molecular projected density of states (PDOS) be systematically used in electronic conductance analysis?

• Tonatiuh Rangel,
• Gian-Marco Rignanese and
• Valerio Olevano

Beilstein J. Nanotechnol. 2015, 6, 1247–1259, doi:10.3762/bjnano.6.128

• such junctions (including the measurement of their current–voltage characteristics) is, however, still difficult to achieve. In order to obtain a reliable single-molecule zero-bias conductance, it was suggested to resort to a statistically significant sample of tens of thousands of measurements [4

Chains of carbon atoms: A vision or a new nanomaterial?

• Florian Banhart

Beilstein J. Nanotechnol. 2015, 6, 559–569, doi:10.3762/bjnano.6.58

• the electron beam in the microscope; therefore electron irradiation might have played a certain role during the formation of chains. Once the chains were created, current-voltage characteristics were taken. The conductivity of the chains was much lower than predicted from theoretical work. By applying

• carbon structures, on the other hand, can be quite different, depending on a local sp2 or sp3 character at the junction. In the case of local sp3 bonding, the π-electron density would be low at the contact and make the electron transfer difficult. The measured current–voltage characteristics show, for

Electrical properties of single CdTe nanowires

• Elena Matei,
• Camelia Florica,
• Andreea Costas,
• María Eugenia Toimil-Molares and
• Ionut Enculescu

Beilstein J. Nanotechnol. 2015, 6, 444–450, doi:10.3762/bjnano.6.45

• similar behavior for CdTe, as would be expected for objects with similar geometries. In Figure 5 current–voltage characteristics are presented for a nanowire contacted by this approach before and after poly(methyl methacrylate) (PMMA) passivation. A difference of almost an order of magnitude between the

• representation for band gap determination of CdTe deposited at −500 mV. (a) The system of electrodes produced by lithography for contacting the nanowire; (b) an image of an individual nanowire contacted by FIBIM to the larger lithographically prepared electrodes. (a) Current–voltage characteristics for a CdTe

• nanowire contacted by FIBIM; (b) Current–voltage characteristics for a CdTe nanowire contacted by FIBIM after PMMA passivation. Acknowledgements The authors acknowledge the financial support of the Romanian Government through UEFISCDI contract 24/2013. Andreea Costas was supported by the strategic grant

Characterization of 10,12-pentacosadiynoic acid Langmuir–Blodgett monolayers and their use in metal–insulator–metal tunnel devices

• Saumya Sharma,
• Mohamad Khawaja,
• Manoj K. Ram,
• D. Yogi Goswami and
• Elias Stefanakos

Beilstein J. Nanotechnol. 2014, 5, 2240–2247, doi:10.3762/bjnano.5.233

• , horizontal deposition) techniques were used to deposit the PDA film on various substrates (glass, quartz, silicon, and nickel-coated film on glass). The electrochemical, electrical and optical properties of the LB and LS PDA films were studied using cyclic voltammetry, current–voltage characteristics (I–V

• precise control of the thickness of the insulating monolayers proved critical for electron tunneling to take place in the MIM structure. The current–voltage characteristics of the MIM diode revealed tunneling behavior in the fabricated Ni–PDA LB film–Ni structures. Keywords: Langmuir–Blodgett monolayer

• sputtered onto the PDA layers with the aid of a shadow mask. To avoid physical damage to the PDA layers, the RF power during sputtering was kept at only 30 W to sustain enough plasma to allow sputtering of Ni atoms. Current–voltage characteristics of the Ni–PDA–Ni assembly were measured using a

Sequence-dependent electrical response of ssDNA-decorated carbon nanotube, field-effect transistors to dopamine

• Hari Krishna Salila Vijayalal Mohan,
• Jianing An and
• Lianxi Zheng

Beilstein J. Nanotechnol. 2014, 5, 2113–2121, doi:10.3762/bjnano.5.220

• sequence combinations, which interact differently with CNTs as well as DA, and consequently, this influences the FET response. The transistor electrical parameters such as conductance, transconductance, threshold voltage and hysteresis gap extracted from the current–voltage characteristics are indicators

Effect of channel length on the electrical response of carbon nanotube field-effect transistors to deoxyribonucleic acid hybridization

• Hari Krishna Salila Vijayalal Mohan,
• Jianing An,
• Yani Zhang,
• Chee How Wong and
• Lianxi Zheng

Beilstein J. Nanotechnol. 2014, 5, 2081–2091, doi:10.3762/bjnano.5.217

• nanotube surface. However, with increasing channel length, the large channel resistance could be a limiting factor in the detection sensitivity. In particular, the FET electrical parameters such as conductance, transconductance, threshold voltage and hysteresis gap extracted from the current–voltage

• characteristics, which are indicators of the various contributing FET biosensing mechanisms [19], vary with channel length. A change in more than one of these electrical parameters after hybridization indicates the influence of multiple FET mechanisms. Therefore, it becomes essential to take into consideration

Optical properties and electrical transport of thin films of terbium(III) bis(phthalocyanine) on cobalt

• Peter Robaschik,
• Pablo F. Siles,
• Daniel Bülz,
• Peter Richter,
• Manuel Monecke,
• Michael Fronk,
• Svetlana Klyatskaya,
• Daniel Grimm,
• Oliver G. Schmidt,
• Mario Ruben,
• Dietrich R. T. Zahn and
• Georgeta Salvan

Beilstein J. Nanotechnol. 2014, 5, 2070–2078, doi:10.3762/bjnano.5.215

• films presents a transition from a linear ohmic-like transport regime for low voltages to a square law dependence for high voltages. These results appear to be in agreement with a space-charge-limited current process (SCLC). According to G. Horowitz et al., the linear current–voltage characteristics can

• the same location indicated in (b) for the case of an applied voltage of 0.6 V (c), 1.0 V (d) and 1.5 V (e). Transport mechanism for TbPc2 thin films. Red and blue solid lines indicate the average of 20 local I–V spectroscopy cycles. (a) Current–voltage characteristics for TbPc2 thin films. Grey and

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

• 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

• detector is less sensitive to the light intensity, i.e., γ ≤ 1 [20]. This occurs also for the ITO/GaAs/Ti/Au device as shown in the insets of Figure 9a inset and Figure 9b. As mentioned above for the dark-current–voltage characteristics, the ITO/GaAs contacts constitutes a counter barrier with respect to

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

• : 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

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

• 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

• characteristics for the ZnO:Al/ZnONR/Si/Al heterostructures measured under dark (top) and under light conditions (down). SEM images of the three investigated types of structures with different surface morphologies. External quantum efficiency of the PV structures of samples A, B and C based on zinc oxide nanorods

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

• 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

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

• -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

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

• figures. Supporting information gives detailed information about the synthesis of molecules, sample calibration and statistics, stretching and relaxing curves, histograms of stretching and relaxing curves, current–voltage characteristics of TSC in THF/Tol, and best-fit parameters of all current–voltage

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

• 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

• charge transport in more detail. We therefore measured current–voltage characteristics (I(V)s) at a fixed electrode spacing, in the 10−2–10−5 G0 conductance region. In between the I(V) measurements, the interelectrode distance was gradually increased or decreased in steps of about 10 pm, without fusing

• , the zero of the relative electrode displacement for each curve was set to the point where the conductance drops sharply below 1 G0. (c) Current–voltage characteristics taken at various electrode spacings starting from the initial value d0 of junctions exposed to the solvent DCM, and (d) to ZnTPPdT–Pyr

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

• –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

• 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