Thermal transport in kinked nanowires through simulation

• Alexander N. Robillard,
• Graham W. Gibson and
• Ralf Meyer

Beilstein J. Nanotechnol. 2023, 14, 586–602, doi:10.3762/bjnano.14.49

• Alexander N. Robillard Graham W. Gibson Ralf Meyer Bharti School of Engineering and Computer Science, Laurentian University, Sudbury P3E 2C6, Canada 10.3762/bjnano.14.49 Abstract The thermal conductance of nanowires is an oft-explored quantity, but its dependence on the nanowire shape is not

• have been achieved [17][18][19][20]. We have also seen investigations into corrugated nanowires, where a jagged or sinusoidal pattern is inscribed into the edges of the wire [21][22]. In such engineered systems, it is common that there is a decrease in thermal conductance. There is a lack of free paths

• (MD, PMC, and the theoretical solution of the Fourier equation), we find that the thermal conductance of a kinked nanowire varies significantly with the kink angle, but that the trend is not a simple monotonic function of the kink angle. Furthermore, heat flux data yielded by PMC and classical

Comparative molecular dynamics simulations of thermal conductivities of aqueous and hydrocarbon nanofluids

• Adil Loya,
• Antash Najib,
• Fahad Aziz,
• Asif Khan,
• Guogang Ren and
• Kun Luo

Beilstein J. Nanotechnol. 2022, 13, 620–628, doi:10.3762/bjnano.13.54

• ]. The key difference was that kerosene was used as a nonaqueous fluid, whereas in the present study paraffin (eicosane, i.e., C20H42) was used. Nevertheless, in their study, partially ionic systems demonstrated a higher increase in thermal conductance than kerosene-based systems. Therefore, our study

An implementation of spin–orbit coupling for band structure calculations with Gaussian basis sets: Two-dimensional topological crystals of Sb and Bi

• Sahar Pakdel,
• Mahdi Pourfath and
• J. J. Palacios

Beilstein J. Nanotechnol. 2018, 9, 1015–1023, doi:10.3762/bjnano.9.94

• potential applications in optoelectronics [34][35][36][37], low thermal conductance with low electrical resistivity for energy generation through thermoelectricity [38], and exotic topological features under strain [39][40][41]. However, it was not until last year that few experimental works brought all

Combined scanning probe electronic and thermal characterization of an indium arsenide nanowire

• Tino Wagner,
• Fabian Menges,
• Heike Riel,
• Bernd Gotsmann and
• Andreas Stemmer

Beilstein J. Nanotechnol. 2018, 9, 129–136, doi:10.3762/bjnano.9.15

• reduced considerably by cross-sectional measurements of the contact area. As shown above for this nanowire (Figure 3), the electrical contacts were partly limited by tunnelling through a thin native oxide layer. If we consider the electron contribution to the thermal conductance to be negligible [36

Sub-nanosecond light-pulse generation with waveguide-coupled carbon nanotube transducers

• Felix Pyatkov,
• Svetlana Khasminskaya,
• Vadim Kovalyuk,
• Frank Hennrich,
• Manfred M. Kappes,
• Gregory N. Goltsman,
• Wolfram H. P. Pernice and
• Ralph Krupke

Beilstein J. Nanotechnol. 2017, 8, 38–44, doi:10.3762/bjnano.8.5

•  4d). Higher repetition rates are limited by the setup. In theory, the characteristic timescale of a thermal emitter τtherm solely depends on the mass density ρCNT, the specific heat capacitance cCNT, and thermal conductance g between the CNTs and the substrate, as pointed out previously [11][19

Nonlinear thermoelectric effects in high-field superconductor-ferromagnet tunnel junctions

• Stefan Kolenda,
• Peter Machon,
• Detlef Beckmann and
• Wolfgang Belzig

Beilstein J. Nanotechnol. 2016, 7, 1579–1585, doi:10.3762/bjnano.7.152

• the regime of linear response of the electric and thermal currents to the difference in electric potential or temperature [12][13][14]. In that case the linear response coefficients – electrical and thermal conductance, Seebeck and Peltier coefficients – are related by the famous Onsager symmetry

• therefore neglect this dependence here. Also, the analysis yields the predicted cooling power for δT = 0, and the actual cooling power under finite δT will be smaller due to the backflow of heat via the thermal conductance of the junction. At B = 0, without spin splitting and consequently without linear

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

• thermoelectric properties. For example, the Seebeck coefficient is given by S = −GS/G, where the charge conductance G has been defined in Equation 45, and with f(ω) the free Fermi distribution. Then, we will calculate the electron thermal conductance , with In order to estimate the thermal conductance, one can

• 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

• 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

• temperature T =300 K for the harmonic and anharmonic-mode junctions. In the numerical simulations below the phononic contribution to the thermal conductance is ignored, assuming it to be small compared to its electronic counterpart. A quantitative analysis of the contribution of the phononic thermal

• interest to generalize our results and study the performance of the junction with strong electron–phonon interaction, e.g., by using a polaronic transformation [55][56][57][58][59]. (iv) Phononic thermal conductance. We studied here electron transfer through molecular junctions, but did not discuss phonon

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

• order Vds. Figure 7 shows the thermopower, S, and the electronic contribution to the thermal conductance, κ, of the PM–EBG device. The device generated a maximum thermopower of 280 μV/K at 110 K, which then decreased at higher temperatures, as shown in Figure 7a. Furthermore, the thermal conductance of

• 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

• contribution to the thermal conductance is small compared to the electronic contribution [22]. Therefore, the PM–EBG device shows great potential as a thermoelectric device. Conclusion We have investigated the electrical and thermoelectrical properties of a porphyrin-based molecule bound to electro-burnt

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

• 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

• thermoelectricity requires a strongly suppressed thermal conductivity (κ) since the performance of thermoelectric devices is inversely proportional to the thermal conductivity. On the other hand, the cooling of local hot spots requires a high thermal conductivity [3]. Thermal conductance in a solid is defined by

• Fourier’s law, where q is the heat flux, κ = κpl + κe is the thermal conductance due to phonons (κpl) and electrons (κe) and is the temperature gradient [1]. Nanostructures show significantly different thermal properties than bulk crystals in which acoustic phonons are the main heat carriers. The reasons

Review of nanostructured devices for thermoelectric applications

• Giovanni Pennelli

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

• /∂x = εJ, it is possible to determine T(x) in the legs, and also ΦH and ΦC, so that an expression for the efficiency η can be obtained: where Rg and K are the total electrical resistance and the total thermal conductance of the generator, which can be evaluated respectively from the material

Functionalization of vertically aligned carbon nanotubes

• Eloise Van Hooijdonk,
• Carla Bittencourt,
• Rony Snyders and
• Jean-François Colomer

Beilstein J. Nanotechnol. 2013, 4, 129–152, doi:10.3762/bjnano.4.14

• of carbon exhibits exceptional morphological, physical and chemical properties: high aspect ratio (a length-to-diameter ratio greater than 10 000 and as high as 132 000 000) [5], an extremely high conductance [6], a high structural flexibility [7], and a high thermal conductance [8]. With a high