The effect of nickel doping on electron and phonon transport in the n-type nanostructured thermoelectric material CoSbS

2015 ◽  
Vol 3 (40) ◽  
pp. 10442-10450 ◽  
Author(s):  
Zihang Liu ◽  
Huiyuan Geng ◽  
Jing Shuai ◽  
Zhengyun Wang ◽  
Jun Mao ◽  
...  
Keyword(s):  
Effective Mass ◽  
Carrier Concentration ◽  
Thermoelectric Material ◽  
Phonon Scattering ◽  
Phonon Transport ◽  
Strong Electron ◽  
Nickel Doping ◽  
Electron Phonon Scattering

The optimized carrier concentration, high effective mass and strong electron–phonon scattering for Ni doped CoSbS contribute to the enhanced ZT value.

Study on Phonon Drag Effect and Phonon Transport in Thin Si-on-Insulator Layers

2015 ◽  
Vol 1117 ◽  
pp. 86-89 ◽  
Author(s):  
Hiroya Ikeda ◽  
Takuro Oda ◽  
Yuhei Suzuki ◽  
Yoshinari Kamakura ◽  
Faiz Salleh
Keyword(s):  
Seebeck Coefficient ◽  
Carrier Concentration ◽  
Phonon Scattering ◽  
Phonon Transport ◽  
Infrared Photodetector ◽  
Phonon Drag ◽  
Drag Effect ◽  
Phonon Modes ◽  
Highly Sensitive ◽  
Insulator Layers

The Seebeck coefficient of P-doped ultrathin Si-on-insulator (SOI) layers is investigated for the application to a highly-sensitive thermopile infrared photodetector. It is found that the Seebeck coefficient originating from the phonon drag is significant in the lightly doped region and depends on the carrier concentration with increasing carrier concentration above ~5×1018 cm-3. On the basis of Seebeck coefficient calculations considering both electron and phonon distribution, the phonon-drag part of SOI Seebeck coefficient is mainly governed by the phonon transport, in which the phonon-phonon scattering process is dominant rather than the crystal boundary scattering even in the SOI layer with a thickness of 10 nm. This fact suggests that the phonon-drag Seebeck coefficient is influenced by the phonon modes different from the thermal conductivity.

The effect of electron effective mass mismatch on electron - phonon scattering rate in a quantum well

1997 ◽  
Vol 12 (3) ◽  
pp. 296-299 ◽  
Author(s):  
Zheng Yisong ◽  
Lu Tianquan ◽  
Wang Yiding ◽  
Wu Xuhong ◽  
Zhang Chengxiang ◽  
...  
Keyword(s):  
Quantum Well ◽  
Effective Mass ◽  
Phonon Scattering ◽  
Electron Effective Mass ◽  
Scattering Rate ◽  
Electron Phonon Scattering

scholarly journals Body-centered-cubic structure and weak anharmonic phonon scattering in tungsten

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Yani Chen ◽  
Jinlong Ma ◽  
Shihao Wen ◽  
Wu Li
Keyword(s):  
Phonon Scattering ◽  
Phonon Transport ◽  
High Symmetry ◽  
Body Centered Cubic ◽  
Phonon Branch ◽  
High Frequencies ◽  
Transverse Acoustic ◽  
Two Factors ◽  
Electron Phonon Scattering ◽  
Isotropy Condition

Abstract It was recently found that the anharmonic phonon–phonon scattering in tungsten is extremely weak at high frequencies, leading to a predominance of electron–phonon scattering and consequently anomalous phonon transport behaviors. In this work, we calculate the phonon linewidths of W along high-symmetry directions from first principles. We find that the weak phonon–phonon scattering can be traced back to two factors. The first is the triple degeneracy of the phonon branches at the P and H points, a universal property of elemental body-centered-cubic (bcc) structures. The second is a relatively isotropic character of the phonon dispersions. When both are met, phonon–phonon scattering rates must vanish at the P and H points. The weak phonon–phonon scattering feature is also applicable to Mo and Cr. However, in other elemental bcc substances like Na, the isotropy condition is violated due to the unusually soft character of the lower transverse acoustic phonon branch along the Γ-N direction, opening emission channels and leading to much stronger phonon–phonon scattering. We also look into the distributions of electron mean-free paths (MFPs) at room temperature in tungsten, which can help engineer the resistivity of nanostructured W for applications such as interconnects.

scholarly journals Electron-Phonon Scattering in Si-Doped GaN

1996 ◽  
Vol 449 ◽  
Author(s):  
C. Wetzel ◽  
W. Walukiewicz ◽  
J. W. Ager
Keyword(s):  
Carrier Concentration ◽  
Phonon Scattering ◽  
Variable Temperature ◽  
Small Cross Section ◽  
Free Electron Concentration ◽  
Transient Time ◽  
Detection Scheme ◽  
Si Doped ◽  
Resonant Raman ◽  
Electron Phonon Scattering

ABSTRACTPhonon-plasmon scattering in non-resonant Raman spectroscopy is used to determine the free electron concentration in Si doped GaN films. For various doping concentration and variable temperature the correlation with magneto-transport data is established. The freeze-out of the carrier concentration at low temperature is thus observed in a purely optical detection scheme. We observe a very long transient time of several hours for the carrier concentration as a reaction to temperature variation. This indicates an indirect capture and emission process with a very small cross section. The value of the Faust-Henry coefficient is determined.

Nanostructured Thermoelectric Skutterudite Co1−xNixSb3 Alloys

2008 ◽  
Vol 8 (8) ◽  
pp. 4003-4006 ◽  
Author(s):  
Qinyu He ◽  
Qing Hao ◽  
Xiaowei Wang ◽  
Jian Yang ◽  
Yucheng Lan ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Grain Boundary ◽  
Direct Current ◽  
Figure Of Merit ◽  
Phonon Scattering ◽  
Hot Press ◽  
Ni Doping ◽  
Strong Electron ◽  
Dimensionless Figure Of Merit ◽  
Electron Phonon Scattering

Nanostructured Ni-doped skutterudites Co1−xNixSb3 (with x ranging from 0.01 to 0.09) were prepared by ball milling and direct-current induced hot press. It was found that the thermal conductivity was reduced due to strong electron–phonon scattering from Ni-doping as well as phonon scattering from the increased grain boundary of the nanostructures. A maximum dimensionless figure-of-merit of 0.7 was obtained in Co0.91Ni0.09Sb3 at 525 °C.

Simulation of Sub-Micron Thermal Transport in a MOSFET Using a Hybrid Fourier-BTE Model

2010 ◽  
Author(s):  
James M. Loy ◽  
Dhruv Singh ◽  
Jayathi Y. Murthy
Keyword(s):  
Thermal Transport ◽  
Source Term ◽  
Phonon Scattering ◽  
Phonon Dispersion ◽  
Computational Cost ◽  
Phonon Transport ◽  
Boltzmann Transport ◽  
Hybrid Solver ◽  
Solution Methodology ◽  
Electron Phonon Scattering

Self-heating has emerged as a critical bottleneck to scaling in modern transistors. In simulating heat conduction in these devices, it is important to account for the granularity of phonon transport since electron-phonon scattering occurs preferentially to select phonon groups. However, a complete accounting for phonon dispersion, polarization and scattering is very expensive if the Boltzmann transport equation (BTE) is used. Moreover, difficulties with convergence are encountered when the phonon Knudsen number becomes small. In this paper we simulate a two-dimensional bulk MOSFET hotspot problem using a partially-implicit hybrid BTE-Fourier solver which is significantly less expensive than a full BTE solution, and which shows excellent convergence characteristics. Volumetric heat generation from electron-phonon collisions is taken from a Monte Carlo simulation of electron transport and serves as a heat source term in the governing transport equations. The hybrid solver is shown to perform well in this highly non-equilibrium situation, matching the solutions obtained from a pure all-BTE solution, but at significantly lower computational cost. The paper establishes that this new model and solution methodology are viable for the simulation of thermal transport in other emerging transistor designs and in other nanotechnology applications as well.

Non-Equilibrium Phonon Distributions in Sub-100nm Silicon Transistors

2005 ◽  
Vol 128 (7) ◽  
pp. 638-647 ◽  
Author(s):  
S. Sinha ◽  
E. Pop ◽  
R. W. Dutton ◽  
K. E. Goodson
Keyword(s):  
Phonon Scattering ◽  
Semiconductor Device ◽  
Transport Model ◽  
Ballistic Transport ◽  
Longitudinal Optical ◽  
Phonon Transport ◽  
Silicon Transistors ◽  
Zero Group ◽  
Electron Phonon Scattering ◽  
Non Equilibrium

Intense electron-phonon scattering near the peak electric field in a semiconductor device results in nanometer-scale phonon hotspots. Past studies have argued that ballistic phonon transport near such hotspots serves to restrict heat conduction. We reexamine this assertion by developing a new phonon transport model. In a departure from previous studies, we treat isotropic dispersion in all phonon branches and include a phonon emission spectrum from independent Monte Carlo simulations of electron-phonon scattering. We cast the model in terms of a non-equilibrium phonon distribution function and compare predictions from this model with data for ballistic transport in silicon. The solution to the steady-state transport equations for bulk silicon transistors shows that energy stagnation at the hotspot results in an excess equivalent temperature rise of about 13% in a 90nm gate-length device. Longitudinal optical phonons with non-zero group velocities dominate transport. We find that the resistance associated with ballistic transport does not overwhelm that from the package unless the peak power density approaches 50W∕μm3. A transient calculation shows negligible phonon accumulation and retardation between successive logic states. This work highlights and reduces the knowledge gaps in the electro-thermal simulation of transistors.

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