Computational Solid State Physics 計算物性学特論 第9回 9. Transport properties I: Diffusive transport.

Slides:



Advertisements
Similar presentations
Anderson localization: from single particle to many body problems.
Advertisements

Lecture #5 OUTLINE Intrinsic Fermi level Determination of E F Degenerately doped semiconductor Carrier properties Carrier drift Read: Sections 2.5, 3.1.
Solid state midterm report Quantum Hall effect g Chienchung Chen.
1 Prof. Ming-Jer Chen Department of Electronics Engineering National Chiao-Tung University October 2, 2014 DEE4521 Semiconductor Device Physics Lecture.
Electrical Transport BW, Chs 4 & 8; YC, Ch 5; S, Chs 4 & 5
ECE 875: Electronic Devices Prof. Virginia Ayres Electrical & Computer Engineering Michigan State University
Semiconductor Device Physics Lecture 3 Dr. Gaurav Trivedi, EEE Department, IIT Guwahati.
Computational Solid State Physics 計算物性学特論 第2回 2.Interaction between atoms and the lattice properties of crystals.
Computational Electronics Generalized Monte Carlo Tool for Investigating Low-Field and High Field Properties of Materials Using Non-parabolic Band Structure.
Hot Electron Energy Relaxation In AlGaN/GaN Heterostructures 1 School Of Physics And Astronomy, University of Nottingham, University Park, Nottingham,
Department of Aeronautics and Astronautics NCKU Nano and MEMS Technology LAB. 1 Chapter III June 1, 2015June 1, 2015June 1, 2015 Carrier Transport Phenomena.
Lecture Number 4: Charge Transport and Charge Carrier Statistics Chem 140a: Photoelectrochemistry of Semiconductors.
Advanced Semiconductor Physics ~ Dr. Jena University of Notre Dame Department of Electrical Engineering SIZE DEPENDENT TRANSPORT IN DOPED NANOWIRES Qin.
The effective mass Conductivity effective mass – determines mobility.
Last Time Free electron model Density of states in 3D Fermi Surface Fermi-Dirac Distribution Function Debye Approximation.
Review-QM’s and Density of States Last time, we used a quantum mechanical, kinetic model, and solved the Schrodinger Equation for an electron in a 1-D.
ME 595M J.Murthy1 ME 595M: Computational Methods for Nanoscale Thermal Transport Lecture 6: Introduction to the Phonon Boltzmann Transport Equation J.
Disorder and chaos in quantum system: Anderson localization and its generalization (6 lectures) Boris Altshuler (Columbia) Igor Aleiner (Columbia)
ENE 311 Lecture 2. Diffusion Process The drift current is the transport of carriers when an electric field is applied. There is another important carrier.
Computational Solid State Physics 計算物性学特論 第8回 8. Many-body effect II: Quantum Monte Carlo method.
Introduction to Monte Carlo Simulation. What is a Monte Carlo simulation? In a Monte Carlo simulation we attempt to follow the `time dependence’ of a.
6. Free Electron Fermi Gas Energy Levels in One Dimension Effect of Temperature on the Fermi-Dirac Distribution Free Electron Gas in Three Dimensions Heat.
Basic Electronics By Asst Professor : Dhruba Shankar Ray For B.Sc. Electronics Ist Year 1.
Chapter 5 Junctions. 5.1 Introduction (chapter 3) 5.2 Equilibrium condition Contact potential Equilibrium Fermi level Space charge at.
Specific Heat of Solids Quantum Size Effect on the Specific Heat Electrical and Thermal Conductivities of Solids Thermoelectricity Classical Size Effect.
Lecture 4 OUTLINE Semiconductor Fundamentals (cont’d)
Numericals on semiconductors
Yoon kichul Department of Mechanical Engineering Seoul National University Multi-scale Heat Conduction.
L4 ECE-ENGR 4243/ FJain 1 Derivation of current-voltage relation in 1-D wires/nanotubes (pp A) Ballistic, quasi-ballistic transport—elastic.
Mobility 2 The average momentum is proportional to the applied force, which is qE. The electrons, on an average, collide in time n (called momentum relaxation.
Electrical and Thermal Conduction
Computational Solid State Physics 計算物性学特論 第10回 10. Transport properties II: Ballistic transport.
Jean Baptiste Perrin Nobel Prize in physics 1926 He demonstrated that the current in a vacuum tube was due to electron motion.
Magnetothermopower in high-mobility 2D electron gas: effect of microwave irradiation Oleg Raichev Department of Theoretical Physics Institute of Semiconductor.
Lecture 4.0 Properties of Metals. Importance to Silicon Chips Metal Delamination –Thermal expansion failures Chip Cooling- Device Density –Heat Capacity.
ELECTRON THEORY OF METALS 1.Introduction: The electron theory has been developed in three stages: Stage 1.:- The Classical Free Electron Theory : Drude.
Electron and Hole Concentrations in Extrinsic Semiconductor
Introduction to Semiconductor Technology. Outline 3 Energy Bands and Charge Carriers in Semiconductors.
Dr. Nasim Zafar Electronics 1 EEE 231 – BS Electrical Engineering Fall Semester – 2012 COMSATS Institute of Information Technology Virtual campus Islamabad.
1 Electrical Conductivity Measured Data Material  [1/(  m)] Copper, Silver 5×10 7 Iron 1×10 7 Manganese 2×10 5 Germanium 1×10 0 Silicon 1×10 -3 Gallium.
Overview of Solid State Physics Starting from the Drude Model.
Free electron theory of Metals
EE105 - Spring 2007 Microelectronic Devices and Circuits
Electron & Hole Statistics in Semiconductors A “Short Course”. BW, Ch
Conduction processes in semiconductors. Two form of charge carrier transport (1) Drift (due to E-field) (2) Diffusion (due to density gradient) for two.
3/23/2015PHY 752 Spring Lecture 231 PHY 752 Solid State Physics 11-11:50 AM MWF Olin 107 Plan for Lecture 23:  Transport phenomena and Fermi liquid.
Thermal Properties of Materials
3/25/2015PHY 752 Spring Lecture 241 PHY 752 Solid State Physics 11-11:50 AM MWF Olin 107 Plan for Lecture 23:  Transport phenomena – Chap. 17.
President UniversityErwin SitompulSDP 3/1 Dr.-Ing. Erwin Sitompul President University Lecture 3 Semiconductor Device Physics
Quantum Hall Effect and Fractional Quantum Hall Effect.
Chapter 7 in the textbook Introduction and Survey Current density:
Nanoelectronics Part II Many Electron Phenomena Chapter 10 Nanowires, Ballistic Transport, and Spin Transport
Semiconductor Device Modeling
Advanced Solid State Physics
“Low Field”  Ohm’s “Law” holds J  σE or vd  μE
Dynamical correlations & transport coefficients
EE 315/ECE 451 Nanoelectronics I
Chapter 3 Plasma as fluids
Novel Scattering Mechanisms for Nanotube-Silicon Devices
Prof. Jang-Ung Park (박장웅)
Electrical Properties of Materials
Lecture #5 OUTLINE Intrinsic Fermi level Determination of EF
Lecture 1: Semiclassical wave-packet dynamics and the Boltzmann equation Dimi Culcer UNSW.
Dynamical correlations & transport coefficients
Review of semiconductor physics
The Free Electron Fermi Gas
Quasi-Classical Approach What was Lord Kelvin’s name?
Chapter 5 - Phonons II: Quantum Mechanics of Lattice Vibrations
Chapter 6 Carrier Transport.
Presentation transcript:

Computational Solid State Physics 計算物性学特論 第9回 9. Transport properties I: Diffusive transport

Electron transport properties l e : mean free path of electrons l φ : phase coherence length λ F : Fermi wavelength

Examples of quantum transport l e : mean free path of electrons l φ : phase coherence length λ F : Fermi wavelength single electron charging key quantities

Point contact: ballistic quantum conductance

Aharanov Bohm effect: phase coherent quantum magnetic flux

Quantum dot: single electron charging

Shubnikov-de Haas oscillations and quantum Hall effect

Diffusive transport

Equation of motion for electrons Scattering Rate k: wave vecot of Bloch electron

How to solve equations of motion for electrons with scattering? Relaxation time approximation for scattering Direct numerical solution: Monte Carlo simulation Boltzmann equation for distribution function of electrons

Relaxation time approximation equation of motion current density m: effective mass n: electron concentration E: electric field B: magnetic field

Drude model: B=0 conductivity : drift velocity

Drude model: steady state solution in magnetic field : B is assumed parallel to z. : cyclotron frequency drift velocity

Conductivity tensor in magnetic field

no transverse magneto-resistance Hall effect

Monte Carlo simulation for electron motion Drift Scattering Drift Scattering

: current Drift velocity as a function of time

Boltzmann equation r k Motion of electrons in r-k space during infinitesimal time Interval Δt

Equation of motion for distribution function equation of motion for electron distribution function f k (r,t).

Boltzmann equation Steady state Boltzmann equation

Electron scattering detailed balance condition for transition probability

Scattering term assume: elastic scattering, spherical symmetry

Transport scattering time k k’ Θ kk’ Contribution of forward scattering is not efficient. Contribution of backward scattering is efficient.

Linearized Boltzmann equation Fermi sphere is shifted by electric field.

Current density and conductivity

Electron mobility in GaAs

Energy flux and thermal conductivity thermal conductivity

Problems 9 Calculate both the conductivity and the resistivity tensors in the static magnetic fields, by solving the equation of motion in the relaxation time approximation. Study the temperature dependence of electron mobility in n-type Si. Calculate the electron mobility in n-type silicon for both impurity scattering and acoustic phonon scattering mechanisms, by using the linearized Boltzmann equation.