Conducting composite materials from the biopolymer kappa-carrageenan and carbon nanotubes

• Ali Aldalbahi,
• Jin Chu,
• Peter Feng and
• Marc in het Panhuis

Beilstein J. Nanotechnol. 2012, 3, 415–427, doi:10.3762/bjnano.3.48

• conductivity of films Free-standing films were prepared by evaporative casting and vacuum filtration of KC–CNT dispersions. All films exhibited linear I–V characteristics, i.e., ohmic behaviour (Figure 5a). The total resistance (RT) increased with channel length (Figure 5b), and was found to scale linearly

• waveform generator (Agilent 33220A). I–V measurements were conducted under controlled ambient conditions (21 °C, RH = 45%) as a function of film length, by repeatedly cutting the end of the strip, contacting with the electrodes and remeasuring the I–V characteristics. Film thickness was determined with a

• dispersions. The lines in (c) and (d) are fits to Equation 1 and Equation 2, respectively. (a) I–V characteristics for KC–CNT (channel length 2 cm) and (b) resistance as a function of length for KC–CNT composite films prepared by evaporative casting and vacuum filtration of KC–CNT dispersions. Numbers 1 and 2

Surface functionalization of aluminosilicate nanotubes with organic molecules

• Wei Ma,
• Weng On Yah,
• Hideyuki Otsuka and
• Atsushi Takahara

Beilstein J. Nanotechnol. 2012, 3, 82–100, doi:10.3762/bjnano.3.10

• . studied the I–V characteristics of imogolite and proposed that bound water molecules contribute to the surface conductivity [69][70]. The current flow observed was attributed to the ability of OH groups on the imogolite surface to lose or gain positive charge (a proton) from water molecules resulting in a

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

• )porphyrin) molecular junctions using the lithographic mechanically controllable break-junction (MCBJ) technique at room temperature and cryogenic temperature (6 K). We combined low-bias statistical measurements with spectroscopy of the molecular levels in the form of I(V) characteristics. This combination

• electrode spacing. In contrast, I(V) characteristics on the ZnTPPdT–Pyr junction show a sharper current onset, marked by arrows in Figure 2d. This observation may be viewed as a molecular fingerprint as the marked points correspond to the onset of resonant transport through an energy level of the molecule

• molecular junction are not always reflected in the low-bias trace histograms, supporting high-bias I(V) characteristics are essential for the interpretation of such histograms. Conclusion In summary, we investigated charge transport in ZnTPPdT–Pyr molecular junctions using the lithographic MCBJ technique

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

• conductance states in a molecular junction require a careful statistical analysis of several thousands of individual traces to extract the “most probable” I–V characteristics of a certain molecule under a given set of experimental conditions. This approach is particularly important for single-molecule

• nature of the transport process. In a first approximation, we considered a single-level model in the low-bias limit and with the molecules coupled equally to the leads. We thus evaluated the experimentally observed I–V characteristics based on the following expression ([1] page 366, and [18]): where Δε0

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

• interested in the low temperature domain θ > 1 where thermal broadening of phonon levels is small such that discrete steps appear in the I–V characteristics. Qualitatively, seen from the dynamics of the phonon mode, two regimes can be distinguished according to the adiabaticity parameter ∑/ω0 = σ: For σ < 1

• backward (with prime) rates are the basic ingredients for the approximate treatment, see text for details. I–V-characteristics for symmetric coupling ∑L = ∑R and for varying electron–phonon coupling m0 at inverse temperature θ = 25 (solid) and θ = 10 (dashed). Mean phonon number in nonequilibrium for eV

• = 3ω0 and versus the electron–phonon coupling m0. Phonon number distribution in nonequilibrium for eV = 5ω0, m0 = 0.5 and kBT/ω0 = 0.1 (histogram). The solid line depicts a fit to a Boltzmann distribution. See text for details. I–V-characteristics for equilibrated (solid) and nonequilibrated (dotted