scholarly journals Final report to the Department of Energy, Basic Energy Sciences, Grant No. DE-FG02-97ER45649 [Theoretical study of phonon modes and electron-phonon scattering]

2000 ◽  
Author(s):  
Dr Cynthia R. McIntyre
Keyword(s):  
Theoretical Study ◽  
Phonon Scattering ◽  
Department Of Energy ◽  
Final Report ◽  
Phonon Modes ◽  
Electron Phonon Scattering

A Theoretical study of the Thermoelectric Transport Coefficients of n-type PbTe

2014 ◽  
Vol 1661 ◽  
Author(s):  
Jawaher Al-Otaibi ◽  
Gyaneshwar P. Srivastava
Keyword(s):  
Electronic Transport ◽  
Continuum Model ◽  
Theoretical Study ◽  
Phonon Scattering ◽  
Transport Coefficients ◽  
Single Mode ◽  
Phonon Modes ◽  
Anharmonic Interactions ◽  
Electron Phonon Scattering

ABSTRACTIn this work we present a theoretical study of the transport coefficients of n-type PbTe. The electronic transport coefficients are calculated using the isotropic-nearly-free-electron approximation, including the effect of band non-parabolicity on electron-phonon scattering. The lattice thermal transport coefficient is computed by employing the isotropic continuum model for the dispersion relation for acoustic as well as optical phonon branches, an isotropic anharmonic continuum model for crystal anharmonicity, and the single-mode relaxation time scheme. The role of transverse optical (TO) phonon modes in anharmonic interactions will be discussed in detail.

Electron-Phonon Scattering in GaN/AlN and GaAs/AlAs Quantum Wells

1997 ◽  
Vol 482 ◽  
Author(s):  
T. F. Forbang ◽  
C. R. McIntyre
Keyword(s):  
Quantum Wells ◽  
Optical Phonon ◽  
Phonon Spectrum ◽  
Phonon Scattering ◽  
Relaxation Times ◽  
Longitudinal Optical ◽  
Longitudinal Optical Phonon ◽  
Phonon Modes ◽  
Optical Phonon Scattering ◽  
Electron Phonon Scattering

AbstractWe have studied the effects on the phonon spectrum and on the electron-longitudinal optical phonon scattering in GaN/AlN and GaAs/AlAs quantum wells. Phonon modes and potentials have been calculated for both systems. Results for emission due to electroninterface phonons interactions are presented. We will discuss the implications for relaxation times and electron mobility due to modified LO-phonon scattering in both systems.

Intermittent Phonon Scattering as a Possible Origin of 1/f Fluctuations in Metallic Resistors

2015 ◽  
Vol 14 (02) ◽  
pp. 1550018 ◽  
Author(s):  
Ferdinand Grüneis
Keyword(s):  
Thermal Noise ◽  
Phonon Scattering ◽  
Phonon Modes ◽  
Equilibrium Conditions ◽  
Noise Component ◽  
Intermittent Behavior ◽  
The Mean ◽  
Scattering Time ◽  
Off Time ◽  
Electron Phonon Scattering

We regard a metallic resistor for temperatures T ≫ Θ D (= Debye temperature); under this condition, electron–phonon scattering is the dominant scattering mechanism. We investigate the noise properties under the supposition that phonon scattering is an intermittent process. Intermissions may be caused by an interaction between different phonon modes giving rise to a short break down of a mode. Due to such an intermittent behavior, we obtain — besides thermal noise — a 1/f noise component. Under equilibrium conditions, the 1/f noise term disappears. Under an applied electric field, the electrons are accelerated between collisions resulting in an additional 1/f noise component which can be compared with Hooge's relation. The predicted Hooge coefficient is α ≈ 3 ⋅ 10-3(τ off /τs)2 with τs being the mean electron phonon scattering time and τ off being the mean off-time ( = intermission). We also find 1/f fluctuations in the square of thermal noise suggesting that an applied current only probes 1/f fluctuations which are already present under equilibrium conditions.

Coupled Electro-Thermal Simulation of MOSFETs

2009 ◽  
Author(s):  
Chunjian Ni ◽  
Zlatan Aksamija ◽  
Jayathi Y. Murthy ◽  
Umberto Ravaioli
Keyword(s):  
Thermal Transport ◽  
Phonon Scattering ◽  
Field Effect Transistors ◽  
Device Simulation ◽  
Heat Fluxes ◽  
Oxide Semiconductor ◽  
Boltzmann Transport ◽  
Phonon Modes ◽  
Conduction Model ◽  
Electron Phonon Scattering

Thermal transport in metal-oxide-semiconductor field effect transistors (MOSFETs) due to electron-phonon scattering is simulated using phonon generation rates obtained from an electron Monte Carlo device simulation. The device simulation accounts for a full band description of both electrons and phonons considering 22 types of electron-phonon scattering events. Detailed profiles of phonon emission/absorption rates in the physical and momentum spaces are generated and are used in a MOSFET thermal transport simulation with a recently-developed anisotropic relaxation time model based on the Boltzmann transport equation (BTE). Comparisons with a Fourier conduction model reveal that the anisotropic heat conduction model predicts higher maximum temperatures because it accounts for the bottlenecks in phonon scattering pathways. Heat fluxes leaving the boundaries associated with different phonon polarizations and frequencies are also examined to reveal the main modes responsible for transport. It is found that though the majority of the heat generation is in the optical modes, the heat generated in the acoustic modes is not negligible. The modes primarily responsible for the transport of heat are found to be medium-to-high frequency acoustic phonon modes.

TEMPERATURE DEPENDENCE BEHAVIOR OF ELECTRICAL RESISTIVITY IN NOBLE METALS AT LOW TEMPERATURES

2014 ◽  
Vol 5 (3) ◽  
pp. 982-992 ◽  
Author(s):  
M AL-Jalali
Keyword(s):  
Experimental Data ◽  
Electrical Resistivity ◽  
Temperature Dependence ◽  
Concentration Dependence ◽  
Low Temperatures ◽  
Noble Metals ◽  
Phonon Scattering ◽  
Theoretical Models ◽  
Residual Resistivity ◽  
Electron Phonon Scattering

Resistivity temperature – dependence and residual resistivity concentration-dependence in pure noble metals(Cu, Ag, Au) have been studied at low temperatures. Dominations of electron – dislocation and impurity, electron-electron, and electron-phonon scattering were analyzed, contribution of these mechanisms to resistivity were discussed, taking into consideration existing theoretical models and available experimental data, where some new results and ideas were investigated.

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