Thermal and Thermoelectric Transport in Nanostructures and Low-Dimensional Systems

Shi, Li

doi:10.1080/15567265.2012.667514

Cited by 91 publications

(59 citation statements)

References 170 publications

(307 reference statements)

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“…Researchers have investigated phonon transport in a variety of systems, 1 for example such atomic-scale structures as carbon nanotubes 2 and graphenes, 3 and in semiconductor superlattices, 4,5 membranes containing nanoparticles, 6 porous structures, 7,8 nanowires, 9 and phononic crystal (PnC) nanostructures. [10][11][12] In these structures, the mean free path (MFP) of phonons is longer than the characteristic length of the systems and, thus, ballistic phonon transport is dominant.…”

Section: Introductionmentioning

confidence: 99%

Mechanism of the Reduced Thermal Conductivity of Fishbone-Type Si Phononic Crystal Nanostructures

Nomura

Maire

2014

Journal of Elec Materi

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The mechanism of the reduced thermal conductivity of fishbone-type phononic crystal (PnC) nanostructures, in which ballistic phonon transport is dominant, was investigated with consideration of both the wave and particle nature of phonons. Phononic band diagrams were calculated for an Si nanowire and a fishbone-type PnC structure with a period of 100 nm, and a clear reduction of the group velocity of phonons, because of a zone-folding effect, was shown. Airsuspended Si nanowires and fishbone-type PnC structures were fabricated by electron beam (EB) lithography, and their thermal conductivities were measured by use of the originally developed micro time-domain thermoreflectance method. The PnC structure had a much lower thermal conductivity. We measured the thermal conductivity of a variety of PnC structures with different fin widths to investigate the mechanism of the reduced thermal conductivity observed. The result indicates that the increase of the phonon traveling distance. as a result of the fins, also results in reduced thermal conductivity.

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Section: Introductionmentioning

confidence: 99%

Mechanism of the Reduced Thermal Conductivity of Fishbone-Type Si Phononic Crystal Nanostructures

Nomura

Maire

2014

Journal of Elec Materi

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“…While it is crucial to have a high κ th for transistors so that the heat dissipated during ON-OFF switches can be rapidly evacuated from their active region, thermo-generators rely on a low κ th that allows for an efficient conversion of the available heat into energy. Measurement techniques have evolved to the point where they can provide a deep insight into the thermal conduction of nanowires 10,11 , which is essential for both electronic and thermoelectric applications. A the same time the theoretical understanding of the thermal properties of nanowires has kept improving due to the development of always complexer and more accurate models [12][13][14][15][16][17][18][19][20][21][22][23] .…”

Section: Introductionmentioning

confidence: 99%

Atomistic modeling of anharmonic phonon-phonon scattering in nanowires

Luisier

2012

Phys. Rev. B

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Phonon transport is simulated in ultra-scaled nanowires in the presence of anharmonic phononphonon scattering. A modified valence-force-field model containing four types of bond deformation is employed to describe the phonon bandstructure. The inclusion of five additional bond deformation potentials allows to account for anharmonic effects. Phonon-phonon interactions are introduced through inelastic scattering self-energies solved in the self-consistent Born approximation in the Nonequilibrium Green's Function formalism. After calibrating the model with experimental data, the thermal current, resistance, and conductivity of <100>-, <110>-, and <111>-oriented Si nanowires with different lengths and temperatures are investigated in the presence of anharmonic phononphonon scattering and compared to their ballistic limit. It is found that all the simulated thermal currents exhibit a peak at temperatures around 200 K if phonon scattering is turned-on while they monotonically increase when this effect is neglected. Finally, phonon transport through Si-Ge-Si nanowires is considered.

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“…On the other hand, bulk materials are typically characterized by a strong interdependence between these parameters, which poses limits to the maximum achievable conversion efficiency 1 . Nanostructured semiconductors today offer a host of novel ways to elude part of these constraints and are leading to a promising new direction in TE research [2][3][4] . For instance, present evidences show that phonon conductivity can be significantly suppressed in nanostructures [5][6][7][8][9] and promising results have also been obtained on the tuning of the TE response through an engineering of electron quantum states [10][11][12] .…”

mentioning

confidence: 99%

Noise thermometry applied to thermoelectric measurements in InAs nanowires

Tikhonov

Shovkun

Ercolani

et al. 2016

Semicond. Sci. Technol.

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We apply noise thermometry to characterize charge and thermoelectric transport in single InAs nanowires (NWs) at a bath temperature of 4.2 K. Shot noise measurements identify elastic diffusive transport in our NWs with negligible electron-phonon interaction. This enables us to set up a measurement of the diffusion thermopower. Unlike in previous approaches, we make use of a primary electronic noise thermometry to calibrate a thermal bias across the NW. In particular, this enables us to apply a contact heating scheme, which is much more efficient in creating the thermal bias as compared to conventional substrate heating. The measured thermoelectric Seebeck coefficient exhibits strong mesoscopic fluctuations in dependence on the back-gate voltage that is used to tune the NW carrier density. We analyze the transport and thermoelectric data in terms of approximate Mott's thermopower relation and to evaluate a gate-voltage to Fermi energy conversion factor.Efficient thermoelectric (TE) conversion in solid state devices has been an elusive target for many decades. An ideal TE material should display a large electrical conductivity σ and Seebeck coefficient S, and a small heat conductivity κ 1 . On the other hand, bulk materials are typically characterized by a strong interdependence between these parameters, which poses limits to the maximum achievable conversion efficiency 1 . Nanostructured semiconductors today offer a host of novel ways to elude part of these constraints and are leading to a promising new direction in TE research 2-4 . For instance, present evidences show that phonon conductivity can be significantly suppressed in nanostructures 5-9 and promising results have also been obtained on the tuning of the TE response through an engineering of electron quantum states 10-12 . The investigation of TE effects in nanoscale conductors, though, brings with it a set of technical challenges linked to reproducibility and accuracy in the estimate of the TE properties of single nanostructures. In particular, electrical and heat contact resistances 8,9 are often difficult to predict and measure, as well as the relative impact of the different transport mechanisms in the emergence of the nanomaterials TE properties. In addition, the role of phonons and of their interaction with the electron system is often hard to access in a real nanostructure 13 . This calls for novel measurement methods to correlate various aspects of the TE response of a nanomaterial and sort out the fundamental physics ruling their TE behavior 14,15 .In our work, we investigate the TE response of individual InAs NWs at a temperature of few Kelvins and demonstrate a primary thermometry method based on current noise measurements. Our approach allows first of all a direct measurement of the thermal bias across the device, and covers a fairly large operation temperature range going well beyond the one typically available with superconductive tunnel junctions 16 . In addition, weshow that the investigation of shot noise as a function of the bias offers...

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Thermal and Thermoelectric Transport in Nanostructures and Low-Dimensional Systems

Cited by 91 publications

References 170 publications

Mechanism of the Reduced Thermal Conductivity of Fishbone-Type Si Phononic Crystal Nanostructures

Mechanism of the Reduced Thermal Conductivity of Fishbone-Type Si Phononic Crystal Nanostructures

Atomistic modeling of anharmonic phonon-phonon scattering in nanowires

Noise thermometry applied to thermoelectric measurements in InAs nanowires

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