scholarly journals Coherent phonon scattering effects on thermal transport in thin semiconductor nanowires

2007 ◽  
Vol 76 (15) ◽  
Author(s):  
P. G. Murphy ◽  
J. E. Moore
Keyword(s):  
Thermal Transport ◽  
Phonon Scattering ◽  
Semiconductor Nanowires ◽  
Coherent Phonon ◽  
Scattering Effects ◽  
Thin Semiconductor

scholarly journals Thermal transport in phononic crystals and the observation of coherent phonon scattering at room temperature

2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Seyedhamidreza Alaie ◽  
Drew F. Goettler ◽  
Mehmet Su ◽  
Zayd C. Leseman ◽  
Charles M. Reinke ◽  
...  
Keyword(s):  
Thermal Transport ◽  
Room Temperature ◽  
Phonon Scattering ◽  
Phononic Crystals ◽  
Coherent Phonon

High Thermoelectric Performance of ZnO by Coherent Phonon Scattering and Optimized Charge Transport

2021 ◽  
pp. 2105008
Author(s):  
Somnath Acharya ◽  
Byung‐Kyu Yu ◽  
Junphil Hwang ◽  
Jiyong Kim ◽  
Woochul Kim
Keyword(s):  
Charge Transport ◽  
Phonon Scattering ◽  
Thermoelectric Performance ◽  
Coherent Phonon

Polaron conduction loss in microwave dielectric ceramics

1999 ◽  
Vol 14 (2) ◽  
pp. 500-502
Author(s):  
Seungbum Hong ◽  
Eunah Kim ◽  
Han Wook Song ◽  
Jongwan Choi ◽  
Dae-Weon Kim ◽  
...  
Keyword(s):  
Quality Factor ◽  
Phonon Scattering ◽  
Dielectric Resonators ◽  
Frequency Range ◽  
Conduction Loss ◽  
Microwave Dielectric ◽  
Scattering Effects ◽  
Unloaded Quality Factor ◽  
Dielectric Ceramics ◽  
Polaron Conduction

It has been generally accepted that the product of the unloaded quality factor and resonant frequency is the universal parameter for comparison of dielectric resonators with different size.1,2 However, it is suggested in this study that this universal parameter should be modified due to the presence of the polarons. From the frequency dependence of the unloaded quality factor, it is possible to extract the factor determined only by the phonon scattering effects, and we denoted this parameter by Qs. It was found that the Qs parameter for ZrxSnzTiyO4 (ZST) and Ba(Zn1/3Ta2/3)O3 (BZT) ceramics showed constancy in the frequency range of 2–12 GHz, which supports the idea of polaron conduction loss contribution to the dielectric loss.

Coherent phonon thermal transport in nanoribbons of gold and silver

2019 ◽  
Author(s):  
Gurvinder Singh ◽  
Krishan Kumar ◽  
R. K. Moudgil
Keyword(s):  
Thermal Transport ◽  
Coherent Phonon

Effects of composition and phonon scattering mechanisms on thermal transport in MFI zeolite films

2007 ◽  
Vol 102 (5) ◽  
pp. 053523 ◽  
Author(s):  
Yeny Hudiono ◽  
Abraham Greenstein ◽  
Carine Saha-Kuete ◽  
Brandon Olson ◽  
Samuel Graham ◽  
...  
Keyword(s):  
Thermal Transport ◽  
Phonon Scattering ◽  
Mfi Zeolite ◽  
Scattering Mechanisms ◽  
Zeolite Films

scholarly journals Reduction of Lattice Thermal Conductivity in PbTe Induced by Artificially Generated Pores

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Jae-Yeol Hwang ◽  
Eun Sung Kim ◽  
Syed Waqar Hasan ◽  
Soon-Mok Choi ◽  
Kyu Hyoung Lee ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Pore Structure ◽  
Transport Properties ◽  
Thermoelectric Materials ◽  
Thermal Transport ◽  
Lattice Thermal Conductivity ◽  
Phonon Scattering ◽  
Phonon Modes ◽  
Thermal Transport Properties

Highly dense pore structure was generated by simple sequential routes using NaCl and PVA as porogens in conventional PbTe thermoelectric materials, and the effect of pores on thermal transport properties was investigated. Compared with the pristine PbTe, the lattice thermal conductivity values of pore-generated PbTe polycrystalline bulks were significantly reduced due to the enhanced phonon scattering by mismatched phonon modes in the presence of pores (200 nm–2 μm) in the PbTe matrix. We obtained extremely low lattice thermal conductivity (~0.56 W m−1 K−1at 773 K) in pore-embedded PbTe bulk after sonication for the elimination of NaCl residue.

Anharmonic Phonon Interactions at Interfaces and Contributions to Thermal Boundary Conductance

2011 ◽  
Vol 133 (6) ◽  
Author(s):  
Patrick E. Hopkins ◽  
John C. Duda ◽  
Pamela M. Norris
Keyword(s):  
Inelastic Scattering ◽  
Thermal Transport ◽  
Phonon Scattering ◽  
Transmission Model ◽  
Material Interfaces ◽  
Physical Consideration ◽  
New Model ◽  
Thermal Boundary Conductance ◽  
Anharmonic Coupling ◽  
Scattering Events

Continued reduction in characteristic dimensions in nanosystems has given rise to increasing importance of material interfaces on the overall system performance. With regard to thermal transport, this increases the need for a better fundamental understanding of the processes affecting interfacial thermal transport, as characterized by the thermal boundary conductance. When thermal boundary conductance is driven by phononic scattering events, accurate predictions of interfacial transport must account for anharmonic phononic coupling as this affects the thermal transmission. In this paper, a new model for phononic thermal boundary conductance is developed that takes into account anharmonic coupling, or inelastic scattering events, at the interface between two materials. Previous models for thermal boundary conductance are first reviewed, including the diffuse mismatch model, which only considers elastic phonon scattering events, and earlier attempts to account for inelastic phonon scattering, namely, the maximum transmission model and the higher harmonic inelastic model. A new model is derived, the anharmonic inelastic model, which provides a more physical consideration of the effects of inelastic scattering on thermal boundary conductance. This is accomplished by considering specific ranges of phonon frequency interactions and phonon number density conservation. Thus, this model considers the contributions of anharmonic, inelastically scattered phonons to thermal boundary conductance. This new anharmonic inelastic model shows improved agreement between the thermal boundary conductance predictions and experimental data at the Pb/diamond and Au/diamond interfaces due to its ability to account for the temperature dependent changing phonon population in diamond, which can couple anharmonically with multiple phonons in Pb and Au. We conclude by discussing phonon scattering selection rules at interfaces and the probability of occurrence of these higher order anharmonic interfacial phonon processes quantified in this work.

scholarly journals Thermal transport in nanocrystalline Si and SiGe by ab initio based Monte Carlo simulation

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Lina Yang ◽  
Austin J. Minnich
Keyword(s):  
Thermal Conductivity ◽  
Monte Carlo ◽  
Ab Initio ◽  
Grain Boundaries ◽  
Thermal Transport ◽  
Phonon Scattering ◽  
Phonon Dispersion ◽  
Computational Study ◽  
Phonon Transport ◽  
Nanocrystalline Si

Abstract Nanocrystalline thermoelectric materials based on Si have long been of interest because Si is earth-abundant, inexpensive, and non-toxic. However, a poor understanding of phonon grain boundary scattering and its effect on thermal conductivity has impeded efforts to improve the thermoelectric figure of merit. Here, we report an ab-initio based computational study of thermal transport in nanocrystalline Si-based materials using a variance-reduced Monte Carlo method with the full phonon dispersion and intrinsic lifetimes from first-principles as input. By fitting the transmission profile of grain boundaries, we obtain excellent agreement with experimental thermal conductivity of nanocrystalline Si [Wang et al. Nano Letters 11, 2206 (2011)]. Based on these calculations, we examine phonon transport in nanocrystalline SiGe alloys with ab-initio electron-phonon scattering rates. Our calculations show that low energy phonons still transport substantial amounts of heat in these materials, despite scattering by electron-phonon interactions, due to the high transmission of phonons at grain boundaries, and thus improvements in ZT are still possible by disrupting these modes. This work demonstrates the important insights into phonon transport that can be obtained using ab-initio based Monte Carlo simulations in complex nanostructured materials.

Coherent phonon scattering in ZnO and ZnS at sulfite and oxygen impurities

2012 ◽  
Vol 210 (1) ◽  
pp. 125-130 ◽  
Author(s):  
M. Bachmann ◽  
M. Czerner ◽  
C. Heiliger
Keyword(s):  
Phonon Scattering ◽  
Coherent Phonon ◽  
Oxygen Impurities
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