Heat transport through atomic contacts

Mosso, Nico; Drechsler, Ute; Menges, Fabian; Nirmalraj, Peter N.; Karg, Siegfried; Riel, Heike; Gotsmann, Bernd

doi:10.1038/nnano.2016.302

Cited by 106 publications

(144 citation statements)

References 42 publications

Supporting

Mentioning

135

Contrasting

Order By: Relevance

“…In fact, Refs. [23,24] reported slight deviations from the Wiedemann-Franz law that were actually attributed to the contribution of phonons and possibly to a small one of photons (thermal radiation) [23]. In this respect, we already showed in Ref.…”

Section: Introductionmentioning

confidence: 58%

“…Our results, in turn, may prove important for related systems such as single-molecule junctions, whose thermal transport properties should soon be amenable to measurement with the very same techniques that have finally enabled the exploration of the thermal conductance of metallic atomic contacts [23,24].…”

Section: Discussionmentioning

confidence: 85%

“…In summary, motivated by recent experiments [23,24], we have used state-of-the-art theoretical techniques to perform a systematic study of the thermal conductance of metallic atomic-size contacts made of Au, Pt, and Al. In particular we have investigated two points of special interest, namely the contribution of phonons to the thermal transport and the validity of the Wiedemann-Franz law.…”

Section: Discussionmentioning

confidence: 99%

“…[23,24] was that the thermal conductance of atomic contacts follows closely the Wiedemann-Franz law, irrespective of the material and the contact size. This law establishes that the thermal conductance of a metal, where the heat transport is dominated by electrons, is simply proportional to its electrical conductance.…”

Section: Introductionmentioning

confidence: 97%

See 3 more Smart Citations

Thermal conductance of metallic atomic-size contacts: Phonon transport and Wiedemann-Franz law

et al. 2017

View full text Add to dashboard Cite

], we present here an extensive theoretical analysis of the thermal conductance of atomic-size contacts made of three different metals, namely gold (Au), platinum (Pt), and aluminum (Al). The main goal of this work is to elucidate the role of phonons in the thermal transport through these atomic contacts as well as to study the validity of the Wiedemann-Franz law, which relates the electrical and the thermal conductance. For this purpose, we have employed two different custom-developed theoretical approaches. The first one is a transport method based on density functional theory (DFT) that allows one to accurately compute the contributions of both electrons and phonons to the thermal transport in few-atom-thick contacts. The second technique is based on a combination of classical molecular dynamics (MD) simulations and a tight-binding model that enables the efficient calculation of the electronic contribution to the thermal conductance of atomic contacts of larger size. Our DFT-based calculations show that the thermal conductance of few-atom contacts of Au and Pt is dominated by electrons, with phonons giving a contribution typically below 10% of the total thermal conductance, depending on the contact geometry. For these two metals we find that the small deviations from the Wiedemann-Franz law, reported experimentally, largely stem from phonons. In the case of Al contacts we predict that the phononic contribution can be considerably larger with up to 40% of the total thermal conductance. We show that these differences in the phononic contribution across metals originate mainly from their distinct Debye energies. On the other hand, our MD-based calculations demonstrate that the electronic contribution to the thermal conductance follows very closely the Wiedemann-Franz law, irrespective of the material and the contact size. Finally, the ensemble of our results consistently shows that the reported observation of quantized thermal transport at room temperature is restricted to few-atom contacts of Au, a monovalent metal in which the transport is dominated by the s valence orbitals. In the case of multivalent metals like Pt and Al this quantization is statistically absent due to the fact that additional orbitals contribute to the transport with conduction channels that have intermediate transmissions between 0 and 1, even in the case of single-atom contacts.

show abstract

Section: Introductionmentioning

confidence: 58%

Section: Discussionmentioning

confidence: 85%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 97%

See 2 more Smart Citations

Thermal conductance of metallic atomic-size contacts: Phonon transport and Wiedemann-Franz law

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Finally, we also show that similar concepts apply to the case of OPE3 and, in particular, we find a clear difference between para-and meta-OPE3, where the central benzene ring is connected in para or meta position. Our work provides concrete predictions that can potentially be tested, given the recent experimental advances in the measurement of the thermal conductance of atomic-scale contacts 52,53 . In addition, it sheds light on the importance of phonon interference effects to tune the thermal transport of molecular junctions.…”

Section: Introductionmentioning

confidence: 99%

Tuning the thermal conductance of molecular junctions with interference effects

2017

View full text Add to dashboard Cite

We present an ab initio study of the role of interference effects in the thermal conductance of single-molecule junctions. To be precise, using a first-principles transport method based on density functional theory, we analyze the coherent phonon transport in single-molecule junctions made of several benzene and oligo-phenylene-ethynylene derivatives. We show that the thermal conductance of these junctions can be tuned via the inclusion of substituents, which induces destructive interference effects and results in a decrease of the thermal conductance with respect to the unmodified molecules. In particular, we demonstrate that these interference effects manifest as antiresonances in the phonon transmission, whose energy positions can be tuned by varying the mass of the substituents. Our work provides clear strategies for the heat management in molecular junctions and more generally in nanostructured metal-organic hybrid systems, which are important to determine, how these systems can function as efficient energy-conversion devices such as thermoelectric generators and refrigerators.

show abstract

Nanoscale Organic Thermoelectric Materials: Measurement, Theoretical Models, and Optimization Strategies

Zeng

Cao

et al. 2019

Adv Funct Materials

112

View full text Add to dashboard Cite

The demands for waste heat energy recovery from industrial production, solar energy, and electronic devices have resulted in increasing attention being focused on thermoelectric materials. Over the past two decades, significant progress is achieved in inorganic thermoelectric materials. In addition, with the proliferation of wireless mobile devices, economical, efficient, lightweight, and bio‐friendly organic thermoelectric (OTE) materials have gradually become promising candidates for thermoelectric devices used in room‐temperature environments. With the development of experimental measurement techniques, the manufacturing for nanoscale thermoelectric devices has become possible. A large number of studies have demonstrated the excellent performance of nanoscale thermoelectric devices, and further improvement of their thermoelectric conversion efficiency is expected to have a significant impact on global energy consumption. Here, the development of experimental measurement methods, theoretical models, and performance modulation for nanoscale OTE materials are summarized. Suggestions and prospects for the future development of these devices are also provided.

show abstract

Heat transport through atomic contacts

Cited by 106 publications

References 42 publications

Thermal conductance of metallic atomic-size contacts: Phonon transport and Wiedemann-Franz law

Thermal conductance of metallic atomic-size contacts: Phonon transport and Wiedemann-Franz law

Tuning the thermal conductance of molecular junctions with interference effects

Nanoscale Organic Thermoelectric Materials: Measurement, Theoretical Models, and Optimization Strategies

Contact Info

Product

Resources

About