Charge and heat transport in soft nanosystems in the presence of time-dependent perturbations

• Alberto Nocera,
• Carmine Antonio Perroni,
• Vincenzo Marigliano Ramaglia and
• Vittorio Cataudella

Beilstein J. Nanotechnol. 2016, 7, 439–464, doi:10.3762/bjnano.7.39

• vibrational modes and the electronic degrees of freedom affects the thermoelectric properties within the linear response regime finding out that the phonon thermal conductance provides an important contribution to the figure of merit at room temperature. Our work has been stimulated by recent experimental

• to the figure of merit ZT at room temperature. Parameters appropriate for junctions based on C60 molecules connected between different metallic leads have been considered for the thermoelectric transport. We have finally generalized the treatment of the heat transport to the case where also electron

• phonon thermal conductance can be calculated within the linear-response regime [90][91] around the temperature T as The total thermal conductance is then given by the sum GK of the electron and phonon thermal conductance: Therefore, one can easily evaluate the total figure of merit ZT (valid in the

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

• electrical and thermal conductances are sensitive to whether the mode is harmonic/anharmonic, the Seebeck coefficient, the thermoelectric figure-of-merit, and the thermoelectric efficiency beyond linear response, conceal this information. Keywords: counting statistics; efficiency; molecular junctions

• thermal conductance and the (dimensionless) thermoelectric figure of merit which determine the linear response thermoelectric efficiency. We obtain these coefficients numerically, by simulating Equation 13 under small biases. Figure 2–Figure 4 below display the behavior of G, S, Σ and ZT at room

• figure of merit shows a monotonic behavior, increasing when the broadening of levels becomes small Γ << T as we approach the so called “tight coupling” limit in which charge and heat currents are (optimally) proportional to each other. ZT can be significantly enhanced by tuning the molecule to an off

Nitrogen-doped graphene films from chemical vapor deposition of pyridine: influence of process parameters on the electrical and optical properties

• Andrea Capasso,
• Theodoros Dikonimos,
• Francesca Sarto,
• Alessio Tamburrano,
• Giovanni De Bellis,
• Maria Sabrina Sarto,
• Giuliana Faggio,
• Angela Malara,
• Giacomo Messina and
• Nicola Lisi

Beilstein J. Nanotechnol. 2015, 6, 2028–2038, doi:10.3762/bjnano.6.206

• conductivity is linked to the film thickness as Rs = (σDC·t)−1. We have also calculated a figure of merit (FoM) that can be used to compare the electrical/optical properties of thin transparent conductors made from various materials. Such FoM is defined as the conductivity ratio, σDC/σOp [16]. The temperature

Simulation of thermal stress and buckling instability in Si/Ge and Ge/Si core/shell nanowires

• Suvankar Das,
• Amitava Moitra,
• Mishreyee Bhattacharya and
• Amlan Dutta

Beilstein J. Nanotechnol. 2015, 6, 1970–1977, doi:10.3762/bjnano.6.201

• and suitability as novel thermoelectric devices [7]. This effect is found to be extremely prominent for ultrathin nanowires with diameters smaller than ≈20 nm [8]. The figure of merit can be further improved by introducing surface disorder without compromising the excellent electronic conductance [9

Simple and efficient way of speeding up transmission calculations with k-point sampling

• Jesper Toft Falkenberg and
• Mads Brandbyge

Beilstein J. Nanotechnol. 2015, 6, 1603–1608, doi:10.3762/bjnano.6.164

• -points are needed due to the rapid variations of these functions for individual k-points [6]. Certain quantities, for example the Seebeck coefficient and thermo-electric figure of merit (ZT), are based on the detailed behavior of the transmission [7][8] and thus exceedingly sensitive to energy and k

Electron and heat transport in porphyrin-based single-molecule transistors with electro-burnt graphene electrodes

• Hatef Sadeghi,
• Sara Sangtarash and
• Colin J. Lambert

Beilstein J. Nanotechnol. 2015, 6, 1413–1420, doi:10.3762/bjnano.6.146

• small as 10 meV increases the thermopower to 475 μV/K. In contrast, the electronic thermal conductance of the device is quite low and does not change significantly with the small variation of the Fermi energy. The thermoelectric figure-of-merit could be high in this device provided the phonon

Enhancing the thermoelectric figure of merit in engineered graphene nanoribbons

• Hatef Sadeghi,
• Sara Sangtarash and
• Colin J. Lambert

Beilstein J. Nanotechnol. 2015, 6, 1176–1182, doi:10.3762/bjnano.6.119

• . In monolayer graphene, this increases the electronic thermoelectric figure of merit ZTe from 0.01 to 0.5. The largest values of ZTe are found when a nanopore is introduced into bilayer graphene, such that the current flows from one layer to the other via the inner surface of the pore, for which

• values as high as ZTe = 2.45 are obtained. All thermoelectric properties can be further enhanced by tuning the Fermi energy of the leads. Keywords: graphene nanoribbons; quantum transport; thermal conductance; thermoelectric figure of merit; thermopower; Introduction Nowadays, the performance of

• for this are changes in the phonon density of states, an increased phonon-boundary scattering and the dispersion of the nanostructures in low dimensional semiconductors [2][4][5][6]. The efficiency of thermoelectric materials and devices is determined by their thermoelectric figure of merit (ZT = S2GT

Hollow plasmonic antennas for broadband SERS spectroscopy

• Gabriele C. Messina,
• Mario Malerba,
• Pierfrancesco Zilio,
• Ermanno Miele,
• Michele Dipalo,
• Lorenzo Ferrara and
• Francesco De Angelis

Beilstein J. Nanotechnol. 2015, 6, 492–498, doi:10.3762/bjnano.6.50

• polarized light impinging at 5° with respect to normal. The simulation layout realistically reproduced the fabricated structure, as depicted in Figure 1a. The scattered field is absorbed by perfectly matched layers placed all around the structure (not shown). As a figure of merit, we considered the electric

Review of nanostructured devices for thermoelectric applications

• Giovanni Pennelli

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

• dissipating system can be reduced. Therefore, the development of a good thermoelectric material, useful for the majority of thermoelectric applications, should aim to maximize the efficiency η (see Equation 11). Hence, the figure of merit , and in particular the factor Z = S2σ/kt, must be as high as possible

• figure of merit of graphene-based thermoelectric generators would be very small. In Figure 3 the efficiency of a thermoelectric generator is reported as a function of the hot source temperature TH. The curves have been evaluated with Equation 11, assuming that the cold source is maintained at room

• thermoelectricity the so-called figure of merit (in general ZT ) has been introduced as a comparison parameter. ZT is a dimensionless parameter that appears explicitly in the efficiency expression (Equation 11), and a material with a ZT value greater than 1 is, in general, considered acceptable for thermoelectric

Integration of ZnO and CuO nanowires into a thermoelectric module

• Dario Zappa,
• Simone Dalola,
• Guido Faglia,
• Elisabetta Comini,
• Matteo Ferroni,
• Caterina Soldano,
• Vittorio Ferrari and
• Giorgio Sberveglieri

Beilstein J. Nanotechnol. 2014, 5, 927–936, doi:10.3762/bjnano.5.106

• ) performance of a material, including the thermal conductivity κ, the electrical conductivity σ and the Seebeck coefficient S. Further, the efficiency of a thermoelectric device depends on the thermoelectric power factor (TPF) and the figure of merit (ZT) of the material, which are defined as S2σ and S2Tσ/κ

• and the figure of merit ZT. In particular, in order to evaluate ZT is necessary to measure the thermal conductivity of the materials. Thermal conductivity measurements are still ongoing, because we need the reengineering of the test device to get rid of the thermal influence of the substrate. We

Hole-mask colloidal nanolithography combined with tilted-angle-rotation evaporation: A versatile method for fabrication of low-cost and large-area complex plasmonic nanostructures and metamaterials

• Jun Zhao,
• Bettina Frank,
• Frank Neubrech,
• Chunjie Zhang,
• Paul V. Braun and
• Harald Giessen

Beilstein J. Nanotechnol. 2014, 5, 577–586, doi:10.3762/bjnano.5.68

• with higher refraction indeces. Additionally, we use the figure of merit (FOM) [27] to study the sensitivity of the Fano resonance quantitatively: Here FWHM is the full width at half maximum of the Fano resonance and defined for the Fano resonance as the distance between the antipeak on the short

Structural and thermoelectric properties of TMGa₃ (TM = Fe, Co) thin films

• Sebastian Schnurr,
• Ulf Wiedwald,
• Paul Ziemann,
• Valeriy Y. Verchenko and
• Andrei V. Shevelkov

Beilstein J. Nanotechnol. 2013, 4, 461–466, doi:10.3762/bjnano.4.54

• annealing in order to improve film crystallinity. In the present study with its emphasis on thermoelectric properties of the (TM)Ga3 films, the related figure of merit [10] ZT = S2σT/λ (S: Seebeck coefficient, σ: electrical conductivity, λ: thermal conductivity, T: Kelvin temperature) indicates that low

Synthesis and thermoelectric properties of Re₃As_6.6In_0.4 with Ir₃Ge₇ crystal structure

• Valeriy Y. Verchenko,
• Anton S. Vasiliev,
• Alexander A. Tsirlin,
• Vladimir A. Kulbachinskii,
• Vladimir G. Kytin and
• Andrei V. Shevelkov

Beilstein J. Nanotechnol. 2013, 4, 446–452, doi:10.3762/bjnano.4.52

• . Re3As6.6In0.4 behaves as a bad metal or heavily doped semiconductor, with electrons being the dominant charge carriers. It possesses high values of Seebeck coefficient and low thermal conductivity, but relatively low electrical conductivity, which leads to rather low values of the thermoelectric figure of merit

• from waste heat (e.g., that stemming from combustion in car engines) or to cool an environment under an external power supply. However, the efficiency of these processes depends on the efficiency of the thermoelectric material in question, which is defined by the value of the figure of merit where T

• sample behaves as a bad metal or heavily doped semiconductor, with electrons being the dominant charge carriers. This compound combines low thermal conductivity with a relatively low electrical conductivity, and therefore, its thermoelectric figure of merit ZT reaches only 0.0008 at room temperature

Thermal noise limit for ultra-high vacuum noncontact atomic force microscopy

• Jannis Lübbe,
• Matthias Temmen,
• Sebastian Rode,
• Philipp Rahe,
• Angelika Kühnle and
• Michael Reichling

Beilstein J. Nanotechnol. 2013, 4, 32–44, doi:10.3762/bjnano.4.4

• corresponding filter does not only reduce the noise but attenuates the NC-AFM signal more than necessary for thermal-noise-limited operation. The RMS value of the total noise is an important figure of merit of the NC-AFM detection system, as it defines the minimum detectable frequency shift. Figure 7b is an

Characterization and properties of micro- and nanowires of controlled size, composition, and geometry fabricated by electrodeposition and ion-track technology

• Maria Eugenia Toimil-Molares

Beilstein J. Nanotechnol. 2012, 3, 860–883, doi:10.3762/bjnano.3.97

• due to theoretical studies predicting a large enhancement of the thermoelectric efficiency, given by the so-called figure of merit ZT, ZT = S2·σ·T/κ, where S is the Seebeck coefficient, σ is the electrical conductivity, κ is the thermal conductivity and T is the temperature. The power factor (S2σ) of

Influence of the diameter of single-walled carbon nanotube bundles on the optoelectronic performance of dry-deposited thin films

• Kimmo Mustonen,
• Toma Susi,
• Antti Kaskela,
• Patrik Laiho,
• Ying Tian,
• Albert G. Nasibulin and
• Esko I. Kauppinen

Beilstein J. Nanotechnol. 2012, 3, 692–702, doi:10.3762/bjnano.3.79

• ]. Since the network resistance scales linearly with the number of contacts, conductance thus scales linearly with the average bundle length. The absorbance (A) and conductance (σDC) can be linked by the so-called figure of merit K [6] where Rs is the sheet resistance and T(λ) (later simply T) the

• synthesized both by using a ferrocene [6] and a HWG aerosol CVD [24], while the scattered data represent the current study. The higher the figure of merit K is, the further left are the data situated in the plot. Referring to Equation 2, we may distinguish two distinct populations of SWCNTs when K is plotted

• line and the purple dashed line represent the literature data used for comparisons. (a) The figure of merit K versus bundle length. A linear dependence of K on Lbundle is observed, as expected from geometric scaling arguments combined with the Beer–Lambert law. The higher the K, the better the