2 18.2 Ohm s Law V = IR where R is the resistance of the material, V is the voltage and I is the current. l R A l R = ρ A where ρ is the resistivity of the material, l is the length of the specimen and A is the area of cross - section. Measurement of Electrical Resistivity
3 Recall from Physics 2211 What are units for I, V, R? Does voltage flow through a material? Why/why not? Units of ρ? Does shape of cross-section affect ρ?
4 18.3 Electrical Conductivity The ease with which a material is capable of conducting an electrical current. 1 σ = ρ whereσ is the electrical conductivity of the material. Units of σ?
5 Ohm s law in a different form J = σε where J is the current density and Ε is the electric field intensity. J = Ε = I A V l Prove equivalence to V = IR for Class work!
6 Energy levels in atoms (Review) In a single isolated atom only certain discrete electron energy levels are allowed
7 18.5 Energy Band Structures in Solids As atoms are brought close together, the electrons are perturbed by the electrons and nuclei of adjacent atoms. Each atomic state is split into a series of closely spaced electron states in the solid electron energy band
9 Energy bands in solids The energy band structure as a function of the interatomic separation distance wider energy band wider energy band
10 Energy bands in solids For large separation distances the electrons associated with any atom are independent of those of the other atoms.
11 Energy bands in solids There is an energy gap E g known as a band gap when the energy levels do not overlap.
12 Energy bands in solids Energy levels overlap to form an extended energy band.
13 Four Types of Energy Bands Valence band the highest energy band that is at least partially occupied (eg. Fig 18.4c) Core bands all the bands below the valence band Conduction band the energy band above the valence band Band gap or energy gap forbidden energy range between the valence and conduction bands
15 Fermi energy The energy corresponding to the highest filled state at 0 K is called the Fermi energy, E f.
16 Classification of solid materials based on electrical conductivity Conductors Semiconductors Insulators What are conductivity ranges for each? See sec. 18.3!
17 18.6 Conduction in terms of band and atomic bonding models Free electrons For an electron to become free it must be excited or promoted into one of the empty and available electron states above E f Only electrons with energies >E f may be accelerated in the presence of an electric field and participate in the conduction process. Holes Electronic entity found in semiconductors and insulators, have energies < E f
18 Metals Band structures in Figs. 18.5a, 18.5b Very little energy is required to promote the Very little energy is required to promote the electrons into the empty states because?
19 For a metal, occupancy of electron states before and after an electron excitation Fermi energy Free electron
21 Insulators and Semiconductors Electrons must be promoted across the energy band gap into the empty states to become free Excitation energy is most often in the form of a non-electrical source such as heat or light
22 For an insulator or semiconductor, occupancy of electron states before and after an electron excitation from the valence band into the conduction band
23 Insulators and semiconductors Energy band gap > 2 ev Ionic or covalent bonding Valence electrons are tightly bound to individual atoms Energy band gap < 2 ev Covalent bonding Valence electrons are not as strongly bound to the atoms Electrons are easily made free by thermal excitation
24 Energy bands and charge carriers Electrical conduction requires the presence of empty energy levels that are not too different in energy levels currently occupied by the electrons.
25 Energy bands and charge carriers An electron jumping from a filled level into a nearby empty level An empty level or a hole is located near the bottom of the band.
26 Energy bands and charge carriers Transition can be viewed as either 13 electrons each moving up one energy level or the empty level moving down 13 levels.
27 18.7 Electron Mobility The ease with which the free electrons move through the solid in response to an electric field. Electric field => force on electron Why doesn t electron continually accelerate? Frictional forces-scattering of electrons due to imperfections in crystal lattice, impurity atoms,vacancies, interstitial atoms, dislocations, thermal vibrations
28 Drift velocity - Average electron velocity in the direction of the force imposed by the electric field. Drift velocity : v d = µ Ε and e e where µ is the electron mobility (frequency of scattering events). e Electrical conductivity : σ = n e µ e where n is the number of free electrons per unit volume = C is the electrical charge on an electron.
31 18.8 Electrical conductivity of metals Electron mobility (or the electrical conductivity) depends on the nature of the charge carriers (the smaller size of electrons permits them to move easily through the solid) temperature Defects in the crystal structure
32 Model of an electron moving through a crystal structure v d = at where v d is the drift velocity a is the acceleration & t is the mean time between collisions. constant acceleration
33 Influence of temperature As temperature is increased atoms gain thermal and kinetic energy mean time between collisions decreases decrease in electron mobility Decrease in electrical conductivity ρ = ρ + at ρ t 0, a 0 = cons. for particular metal
34 Influence of impurities In the presence of impurities mean time between collisions is decreased decrease in electron mobility Decrease in electrical conductivity ρ = c i i Ac i ( 1 c ) i = impurity concetration ( at% /100) A = composition independent cons.
35 For a two-phase alloy ρ V ρ i s s = = = ρ V α α + ρ V β β volume fraction individual res. For a metal, the total electrical resistivity equals the sum of thermal, impurity and deformation contributions See Figure 18.8 ρ = ρ + ρ + ρ total i Mattthiessen ' s rule t d
36 Semiconductors Intrinsic semiconductors Electrical behavior is based on the electronic structure inherent to the pure material. Elemental Si, Ge Extrinsic semiconductors Electrical behavior is dictated by impurity (external) atoms.
37 Intrinsic Characterized by band structure 18.4b At 0K, completely filled valence band Band gap < 2eV Groups III-V compounds, ex. Gallium Arsenide (GaA) Groups IIB-VIA ex. Cadmium Suplhide (Cds) For these compounds, how might wider separation in electronegativity influence the type of bond and band gap energy? Which of ZnS and CdSe will have a larger band gap energy, E g? why?
38 Concept of a hole For every electron excited into the conduction band, there is left behind a missing electron in one of the covalent bonds. This missing electron is treated as a positively charged particle called a hole. A hole has the same magnitude of charge as that of an electron.
39 18.10 Intrinsic Semiconduction
40 Electron bonding model of electrical conduction in intrinsic silicon - before excitation
41 Electron bonding model of electrical conduction in intrinsic silicon - after excitation
42 Intrinsic conductivity Electrical conductivity : σ = n e µ + e p e µ h where p is the number of holes per cubic meter and µ is the hole mobility. σ = n i h For intrinsic semiconductors : n = p = where n e n i i is the intrinsic carrier concentration. Hence, the electrical conductivity : ( µ + µ ) e h
43 Example 18.1 For intrinsic gallium arsenide, the room temperature electrical conductivity is 10-6 (Ωm) -1 ; the electron and hole mobilities are 0.85 and 0.04 m 2 /Vs respectively. Compute the intrinsic carrier concentration n i at room temperature.
44 Problem statement : σ = 10 µ µ n i e h =? 6 ( Ωm) = 0.85m = 0.04 m / Vs / Vs - intrinsic semiconductor Theory : σ = n = p = σ = n e µ + n i e e n i ( µ + µ ) e p e µ For intrinsic semiconductors : h h Hence, the electrical conductivity : Solution : n i = e σ ( µ + µ ) e = h m 3
45 18.11 Extrinsic Semiconductors - n-type extrinsic semiconduction The addition of a Group V atom, such as P into a Si crystal
46 n-type extrinsic semiconduction The addition of a Group V atom, such as P into a Si crystal donor level
47 Extrinsic n-type semiconduction using electron bonding model - before excitation
48 Extrinsic n-type semiconduction using electron bonding model - after excitation
49 Energy band for a donor impurity level
50 Extrinsic n-type conductivity Electrical conductivity : σ = n e µ + p e µ e h For extrinsic n - type semiconductors, # of electrons in the conduction band >> n >> p Hence, the electrical conductivity : # of holes in the valence band : σ n e µ e
51 18.11 Extrinsic Semiconductors - p-type extrinsic semiconduction The addition of a Group III atom, such as B into a Si crystal
52 p-type extrinsic semiconduction The addition of a Group III atom, such as B into a Si crystal acceptor level
53 Extrinsic p-type semiconduction using electron bonding model
54 Energy band for an acceptor impurity level
55 Extrinsic p-type conductivity Electrical conductivity : σ = n e µ + p e µ e h For extrinsic p - type semiconductors, # of electrons in the conduction band << n << p Hence, the electrical conductivity : # of holes in the valence band : σ p e µ h
56 Doping Extrinsic semiconductors are produced from materials that are initially extremely pure. Controlled concentrations of specific donors or acceptors are added.
57 Temperature Dependence of Carrier Concentration How would band gap affect carrier concentration? Ge vs Si? Why concentrations increase with temperature for intrinsic?
58 Temperature Dependence of Carrier Concentration Why concentrations constant with temperature in extrinsic region? As dopant level is increased would you expect the temperature at which a semiconductor becomes in trinsic to increase, to remain essentially the same, or to decrease? Why?
59 Temperature Dependence of Carrier Mobility
60 Example 18.2 Calculate the electrical conductivity of intrinsic silicon at 423 K.
61 Problem statement : σ =? T = 423 K - intrinsic silicon Theory : σ = n = p = σ = n e µ + n i e e n i ( µ + µ ) e p e µ For intrinsic semiconductors : h h Hence, the electrical conductivity :
62 Solution : n i 19 3 ( 423 K ) = 4 10 m
63 µ µ e h ( 423K ) ( 423 K ) Electrical conductivity of σ = n = i e 0.52 = 0.06 m ( µ e + µ h ) ( Ωm) 1 2 = m / Vs 2 / Vs intrinsic Si at 423 K :
64 Example 18.3 To high-purity silicon is added m -3 arsenic atoms. Is this material n-type or p-type semiconductor? Calculate the room temperature electrical conductivity of this material. Compute the conductivity at 100 C.
65 Arsenic is a Group V element - n-type semiconductor
66 Problem statement σ =? : n = m T = 298 K 3 ( room temperature) - n - type extrinsic semiconductor Theory : σ = n e µ + e p e µ h For n - type extrinsic semiconductors : n >> p Hence, the electrical conductivity : σ n e µ e
67 Solution : µ e ( m ) = 0.07 m σ = n e µ = 1120 e 2 / Vs ( Ωm) 1
68 Problem statement σ =? : n = m 3 T = 373 K - n - type extrinsic semiconductor Theory : σ = n e µ + e p e µ h For n - type extrinsic semiconductors : n >> p Hence, the electrical conductivity : σ n e µ e
69 Solution : µ e ( 373 K ) Electrical conductivity : σ = n e µ e = 0.04m = / Vs ( Ωm) 1
Semiconductors 1. Explain different types of semiconductors in detail with necessary bond diagrams. There are two types of semi conductors. 1. Intrinsic semiconductors 2. Extrinsic semiconductors Intrinsic
Electrical Properties Electrical Conduction R Ohm s law V = IR I l Area, A V where I is current (Ampere), V is voltage (Volts) and R is the resistance (Ohms or ) of the conductor Resistivity Resistivity,
Lecture 7: Extrinsic semiconductors - Fermi level Contents 1 Dopant materials 1 2 E F in extrinsic semiconductors 5 3 Temperature dependence of carrier concentration 6 3.1 Low temperature regime (T < T
Microscopic Ohm s Law Outline Semiconductor Review Electron Scattering and Effective Mass Microscopic Derivation of Ohm s Law 1 TRUE / FALSE 1. Judging from the filled bands, material A is an insulator.
Chapter 4: Bonding in Solids and Electronic Properties Free electron theory Consider free electrons in a metal an electron gas. regards a metal as a box in which electrons are free to move. assumes nuclei
Electrical material properties U = I R Ohm s law R = ρ (l/a) ρ resistivity l length σ = 1/ρ σ conductivity A area σ = n q μ n conc. of charge carriers q their charge μ their mobility μ depends on T, defects,
ELECTRICAL PROPERTIES Introduction The objective of this chapter is to explore the electrical properties of materials, i.e. their responses to an applied electric field. We begin with the phenomenon of
EE 446/646 Photovoltaic Devices I Y. Baghzouz What is Photovoltaics? First used in about 1890, the word has two parts: photo, derived from the Greek word for light, volt, relating to electricity pioneer
Electrons in materials (where are they, what is their energy) 1 Lone atoms A single atom has electrons in shells and sub shells. Each of these have a distinct energy level. The diagram shows an example
Lecture 2 Unit Cells and Miller Indexes Reading: (Cont d) Anderson 2 1.8, 2.1-2.7 Unit Cell Concept The crystal lattice consists of a periodic array of atoms. Unit Cell Concept A building block that can
Introduction A semiconductor is a material that has a resistivity lies between that of a conductor and an insulator. The conductivity of a semiconductor material can be varied under an external electrical
ENERGY BANDS AND GAPS IN SEMICONDUCTOR Muhammad Hafeez Javed www.rmhjaved.com email@example.com Out Line Introduction Energy band Classification of materials Direct and indirect band gap of SC Classification
Chem 241 Lecture 24 UMass Amherst Biochemistry... Teaching Initiative Announcement Mistake we have class on the 3 rd not 4 th Exam 3 Originally scheduled April 23 rd (Friday) What about April 26 th (Next
Today From Last Time Important new Quantum Mechanical Concepts Indistinguishability: Symmetries of the wavefunction: Symmetric and Antisymmetric Pauli exclusion principle: only one fermion per state Spin
Advantages / Disadvantages of semiconductor detectors Semiconductor detectors have a high density (compared to gas detector) large energy loss in a short distance diffusion effect is smaller than in gas
Being virtually killed by a virtual laser in a virtual space is just as effective as the real thing, because you are as dead as you think you are. -Douglas Adams, Mostly Harmless David J. Starling Penn
Chapter Two Energy Bands and Effective Mass Energy Bands Formation At Low Temperature At Room Temperature Valence Band Insulators Metals Effective Mass Energy-Momentum Diagrams Direct and Indirect Semiconduction
The German University in Cairo th Electronics 5 Semester Faculty of Information Engineering & Technology Semiconductors (Elct 503) Electronics Department Fall 2014 Problem Set 3 1- a) Find the resistivity
Calculating Band Structure Nearly free electron Assume plane wave solution for electrons Weak potential V(x) Brillouin zone edge Tight binding method Electrons in local atomic states (bound states) Interatomic
electronics fundamentals circuits, devices, and applications THOMAS L. FLOYD DAVID M. BUCHLA Lesson 1: Diodes and Applications Semiconductors Figure 1-1 The Bohr model of an atom showing electrons in orbits
1. What is intrinsic If a semiconductor is sufficiently pure, then it is known as intrinsic semiconductor. ex:: pure Ge, pure Si 2. Mention the expression for intrinsic carrier concentration of intrinsic
5 Feb 14 Semi.1 SEMICONDUCTOR BEHAVIOR AND THE HALL EFFECT The object of this experiment is to study various properties of n- and p-doped germanium crystals. The temperature dependence of the electrical
Qualitative Picture of the Ideal Diode G.R. Tynan UC San Diego MAE 119 Lecture Notes Band Theory of Solids: From Single Attoms to Solid Crystals Isolated Li atom (conducting metal) Has well-defined, isolated
EE495/695 Introduction to Semiconductors I Y. Baghzouz ECE Department UNLV Introduction Solar cells have always been aligned closely with other electronic devices. We will cover the basic aspects of semiconductor
Conductivity and Semi-Conductors J = current density = I/A E = Electric field intensity = V/l where l is the distance between two points Metals: Semiconductors: Many Polymers and Glasses 1 Electrical Conduction
3. Semiconductor eterostructures and nanostructures We discussed before ow te periodicity of a crystal results in te formation of bands. or a 1D crystal, we obtained: a (x) x In 3D, te crystal lattices
Lecture (02) PN Junctions and Diodes By: Dr. Ahmed ElShafee ١ I Agenda N type, P type semiconductors N Type Semiconductor P Type Semiconductor PN junction Energy Diagrams of the PN Junction and Depletion
The electronic structure of solids We need a picture of the electronic structure of solid that we can use to explain experimental observations and make predictions Why is diamond an insulator? Why is sodium
SEMICONDUCTORS Conductivity lies between conductors and insulators The flow of charge in a metal results from the movement of electrons Electros are negatively charged particles (q=1.60x10-19 C ) The outermost
Semiconductor Detectors Summary of Last Lecture Band structure in Solids: Conduction band Conduction band thermal conductivity: E g > 5 ev Valence band Insulator Charge carrier in conductor: e - Charge
Determination of properties in semiconductor materials by applying Matlab Carlos Figueroa. 1, Raúl Riera A. 2 1 Departamento de Ingeniería Industrial. Universidad de Sonora A.P. 5-088, Hermosillo, Sonora.
Charge carriers and conduction: Chapter 12: Electrical Properties Charge carriers include all species capable of transporting electrical charge, including electrons, ions, and electron holes. The latter
EXTRINSIC SEMICONDUCTOR In an extrinsic semiconducting material, the charge carriers originate from impurity atoms added to the original material is called impurity [or] extrinsic semiconductor. This Semiconductor
1 V. Semiconductor Detectors V.1. Principles Semiconductor Detectors are Ionization Chambers Detection volume with electric field Energy deposited positive and negative charge pairs Charges move in field
UNIVERSITY OF CALIFORNIA College of Engineering Department of Electrical Engineering and Computer Sciences EECS 143 Fall 2008 Exam 1 Professor Ali Javey Answer Key Name: SID: 1337 Closed book. One sheet
http://en.wikipedia.org/wiki/bravais_lattice Introduction to Solid State Crystalline vs. non-crystalline solids: Lattice Unit cell No. of spheres in a unit cell : Bravais lattices In geometry and crystallography,
Chapter 3 Properties of Nanostructures In Chapter 2, the reduction of the extent of a solid in one or more dimensions was shown to lead to a dramatic alteration of the overall behavior of the solids. Generally,
ADVANCED UNDERGRADUATE LABORATORY HALL Semiconductor Resistance, Band Gap, and Hall Effect Revisions: September 2016, January 2018: Young-June Kim November 2011, January 2016: David Bailey October 2010:
Lecture 1 Introduction to Electronic Materials Reading: Pierret 1.1, 1.2, 1.4, 2.1-2.6 Atoms to Operational Amplifiers The goal of this course is to teach the fundamentals of non-linear circuit elements
CHAPTER 1 Physical Properties of Elements and Semiconductors 1.1 Introduction Semiconductors constitute a large class of substances which have resistivities lying between those of insulators and conductors.
EE 5211 Analog Integrated Circuit Design Hua Tang Fall 2012 Today s topic: 1. Introduction to Analog IC 2. IC Manufacturing (Chapter 2) Introduction What is Integrated Circuit (IC) vs discrete circuits?
Recitation : Equilibrium Electron and Hole Concentration from Doping Here is a list of new things we learned yesterday: 1. Electrons and Holes. Generation and Recombination 3. Thermal Equilibrium 4. Law
Electronic Properties of Lead Telluride Quantum Wells Liza Mulder Smith College 2013 NSF/REU Program Physics Department, University of Notre Dame Advisors: Profs. Jacek Furdyna, Malgorzata Dobrowolska,
4. lectrons and Holes Solid State Device Fundamentals NS 45 Lecture Course by Alexander M. Zaitsev firstname.lastname@example.org Tel: 718 982 2812 4N101b 1 4. lectrons and Holes Free electrons and holes
Surface physics, Bravais lattice 1. Structure of the solid surface characterized by the (Bravais) lattice + space + point group lattice describes also the symmetry of the solid material vector directions
0. Introduction: Semiconductor device structures are traditionally divided into homojunction devices (devices consisting of only one type of semiconductor material) and heterojunction devices (consisting
Semiconductors and Optoelectronics Advanced Physics Lab, PHYS 3600 Don Heiman, Northeastern University, 2017 Today Semiconductors Acoustics Tomorrow Come to CH325 Exercises Tours Semiconductors and Optoelectronics
RADIATION EFFECTS AND DAMAGE The detrimental consequences of radiation are referred to as radiation damage. To understand the effects of radiation, one must first be familiar with the radiations and their
Pauli Exclusion Principle Electrons in a single atom occupy discrete levels of energy. No two energy levels or states in an atom can have the same energy. Each energy level can contain at most two electrons
- 1-1/15/02C:\lec320.doc H.L.Kwok SEMICONDUCTOR MATERIALS AND DEVICES by H.L. Kwok Objective: The purpose of these notes is to familiarize students with semiconductors and devices including the P-N junction,
- 1-3/4/02C:\lec320.doc H.L.Kwok SEMICONDUCTOR MATERIALS AND DEVICES by H.L. Kwok Objective: The purpose of these notes is to familiarize students with semiconductors and devices including the P-N junction,
Solid State Detectors Most material is taken from lectures by Michael Moll/CERN and Daniela Bortoletto/Purdue and the book Semiconductor Radiation Detectors by Gerhard Lutz. In gaseous detectors, a charged
Colloqium problems to chapter 13 1. What is meant by an intrinsic semiconductor? n = p All the electrons are originating from thermal excitation from the valence band for an intrinsic semiconductor. Then
Chapter 1 INTRODUCTION TO SEMICONDUCTORS MATERIAL Objectives Discuss basic structures of atoms Discuss properties of insulators, conductors, and semiconductors Discuss covalent bonding Describe the conductions
BASIC ELECTRONICS Subject Code: ELN-15/5 IA marks: 5 Hours per week : 04 Exam Hours 03 Total Hrs: 5 Exam Marks: 100 CHAPTER 1 CONDUCTION IN SEMICONDUCTORS Electrons and holes in an intrinsic semiconductors,
Basic Physics of Semiconductors Semiconductor materials and their properties PN-junction diodes Reverse Breakdown EEM 205 Electronics I Dicle University, EEE Dr. Mehmet Siraç ÖZERDEM Semiconductor Physics
Week 13 MO Theory, Solids, & metals Q UEST IO N 1 Using the molecular orbital energy diagrams below, which one of the following diatomic molecules is LEAST likely to exist? A. Li2 B. Be2 C. B2 D. C2 E.
A3-1 HALL EFFECT Last Revision: August, 21 2007 QUESTION TO BE INVESTIGATED How to individual charge carriers behave in an external magnetic field that is perpendicular to their motion? INTRODUCTION The
Problem Set 9 Solutions 1. Mobility in extrinsic semiconductors is affected by phonon scattering and impurity scattering. Thoroughly explain the mobility plots for the following figures from your textbook
5. Semiconductors and P-N junction Thomas Zimmer, University of Bordeaux, France Summary Learning Outcomes... 2 Physical background of semiconductors... 2 The silicon crystal... 2 The energy bands... 3
Physics of Semiconductors. Exercises. The Evaluation of the Fermi Level in Semiconductors. B.I.Lembrikov Department of Communication Engineering Holon Academic Institute of Technology I. Problem 8. The
6.012 - Electronic Devices and Circuits Lecture 2 - Uniform Excitation; Non-uniform conditions Announcements Review Carrier concentrations in TE given the doping level What happens above and below room
HALL EFFECT In a Ga!ium Arsenide Semiconductor Jason Robin Fall 07 Phy Adv Lab Ha! Effect 1 HALL EFFECT In a Ga!ium Arsenide Semiconductor Jason Robin University of Rochester Fall 07 PHY ADV LAB Introduction
Cathkin High School Physics Department CfE Higher Unit 3 Electricity Summary Notes Name Class 3.1 Electrons and Energy Monitoring and measuring alternating current Alternating current Previously, you learned
Introduction into defect studies in ceramic materials(iii) Structure, Defects and Defect Chemistry Z. Wang January 18, 2002 1. Mass, Charge and Site Balance The Schottky reactions for NaCl and MgO, respectively,
Surfaces, Interfaces, and Layered Devices Building blocks for nanodevices! W. Pauli: God made solids, but surfaces were the work of Devil. Surfaces and Interfaces 1 Interface between a crystal and vacuum
Lectures on MEMS and MICROSYSTEMS DESIGN and MANUFACTURE Chapter 3 Engineering Science for Microsystems Design and Fabrication In this Chapter, we will present overviews of the principles of physical and
The Birnie Group solar class and website were created with much-appreciated support from the NSF CRCD Program under grants 0203504 and 0509886. Continuing Support from the McLaren Endowment is also greatly
Surfaces, Interfaces, and Layered Devices Building blocks for nanodevices! W. Pauli: God made solids, but surfaces were the work of Devil. Surfaces and Interfaces 1 Role of surface effects in mesoscopic
KL 4. - characteristics of electric conductors 4.1 ntroduction f an electric conductor is connected to a voltage source with voltage a current is produced. We define resistance being the ratio of the voltage
Section 4 (M&T Chapter 7) Structure and Energetics of Metallic and Ionic Solids Bonding in Solids We have discussed bonding in molecules with three models: Lewis Valence Bond MO Theory These models not
Lecture 4 Detectors for Ionizing Particles Introduction Overview of detector systems Sources of radiation Radioactive decay Cosmic Radiation Accelerators Content Interaction of Radiation with Matter General
Electron-phonon scattering (Finish Lundstrom Chapter ) Deformation potentials The mechanism of electron-phonon coupling is treated as a perturbation of the band energies due to the lattice vibration. Equilibrium
Lecture 8 Equations of State, Equilibrium and Einstein Relationships and Generation/Recombination Reading: (Cont d) Notes and Anderson 2 sections 3.4-3.11 Energy Equilibrium Concept Consider a non-uniformly
Solid State Physics Lecture 10 Band Theory Professor Stephen Sweeney Advanced Technology Institute and Department of Physics University of Surrey, Guildford, GU2 7XH, UK email@example.com Recap from
Chapters 24/25: Current, Circuits & Ohm s law Thursday September 29 th **Register your iclickers** Conductors under dynamic conditions Current, current density, drift velocity Ohm s law Types of conductor
Single Photon detectors Outline Motivation for single photon detection Semiconductor; general knowledge and important background Photon detectors: internal and external photoeffect Properties of semiconductor
University of California at Santa Cruz Jack Baskin School of Engineering Electrical Engineering Department EE-145L: Properties of Materials Laboratory Lab 6: Temperature Dependence of Semiconductor Conductivity
Advanced Level Physics May 06 Paper Mark schemes are prepared by the Examination Board and considered, together with the relevant questions. This mark scheme includes any amendments made at the standardisation
Energy Losses in the Electrical Circuits Motors, lighting systems, wiring, mechanical terminations, distribution panels, protective devices, transformers, switchgear, and all end of circuit equipment experience
6-1 Introduction EXPERIMENT 6 Semiconductors: Preparation of Semiconducting Thin Films Metals are good conductors of electricity. Copper, for example, allows the flow of electrons with relatively little
Ionic Bonding Ion: an atom or molecule that gains or loses electrons (acquires an electrical charge). Atoms form cations (+charge), when they lose electrons, or anions (- charge), when they gain electrons.
The pn Junction: The Shockley Model ( S. O. Kasap, 1990-001) 1 pn JUNCTION THE SHOCKLEY MODEL Safa Kasap Department of Electrical Engineering University of Saskatchewan Canada Although the hole and its
University of Technology 2016 2017 First Year, Lecture One Basic Construction of the Atom: Energy Levels and Atomic Structure The atom is a basic unit of material that consists of central nucleus surrounded
Chapter 9 Molecular Geometry and Bonding Theories 9.1 Molecular Shapes Lewis structures give atomic connectivity (which atoms are physically connected). By noting the number of bonding and nonbonding electron