The pn junction. [Fonstad, Ghione]
|
|
- Bernard Knight
- 5 years ago
- Views:
Transcription
1 The pn junction [Fonstad, Ghione]
2 Band diagram On the vertical axis: potential energy of the electrons On the horizontal axis: now there is nothing: later we ll put the position qf s : work function (F s : extraction potential), depends on doping (which moves E F ) qc s : electron affinity (~ 4 ev for Si) E 0 : vacuum level Now we ll consider the band diagrams in thermal equilibrium only
3 The same material, with different doping If the two samples are isolated from each other, we have -> note: the electron affinity does not change We ll first assume uniform doping in each sample The work function is larger for the p side p side n side
4 The same material, with different doping We have a junction! How to build the band diagram: the Fermi level is constant (if not, electrons would move from zones with higher f(e) to zones with lower f(e), due to the different probability of occupation of the states) electron affinity and forbidden gap width are constant (depend on the material only) far from the junction, the band structure is that of the isolated material the vacuum level is continuous
5 Band diagram in contact 1 st approx. drawing... complete drawing E 0 is now the energy of the electron just outside the material
6 Depletion region and potentials Two integration steps: - [div E=r/e 0 ] constant r => linear E(x) - [E=-dv/dx] linear E(x) -> parabolic j(x) j: electric potential conventionally referred to E Fi U: potential energy of the electrons at E Fi (well, they do not exist...) U=-qj U is also (apart from an offset) the potential energy of the electrons e.g. at the bottom of CB
7 Depletion region Where bands bend, there are two depletion layers, where r~n D or r~n A These are space-charge regions => E => potential The contact potential, or built-in potential, is in order to compute the width of the depletion region, we ll compute with (global neutrality)
8 Depletion region So we get so that And we get with N A x p =N D x n and N eq =(N A N D )/(N A +N D ) So, higher doping => thinner depletion region
9 The two components of the built-in potential Vi
10 Out of thermal equilibrium Reverse bias... forward bias
11 Out of thermal equilibrium
12 Electrons potential energy and concentrations E and j in the depletion region -> <-- minus! E => we have to spend energy to move electrons from right to left i.e. their potential energy U increases when moving from right to left U has the same behaviour of E Fi (and the same of j but with opposite sign) So from [sl. 110/24] we can write
13 The current Let us consider a 1D model (i.e., the section is constant along x) Hypothesis: low injection n, p neglectable in the depletion layers the sides of the junctions (w p, w n ) are much longer than the diffusion lengths L n =(D n t n ) 1/2 and L p =(D p t p ) 1/2 In any section dr dr low injection -> We need to compute the concentrations of minority carriers
14 Junction law The solutions of the diffusion equations are here We need to know n p (-x p ) and p n (x n ) From we get
15 Junction law From we get At equilibrium (V=0) Out of equilibrium (but with low injection): junction law ->
16 Out of equilibrium Carriers profile ->
17 The current E.g. at x=x n J tot (x n )=J p (x n )+J n (x n )=J p, diff (x n )+J n (x n ) Assuming that recombination is neglectable in the space charge region, J n (x n )=J n (-x p )=J n, diff (-x p ) so that J tot (x n )=J p, diff (x n )+J n, diff (-x p ) p n n p
18 The current And we finally get with
19 Effect of temperature Higher T implies higher current, due to changes in - increase in carrier concentration - V T - changes in D n/p and L n/p At constant voltage, I doubles for an increase of 10 o C At constant current, V decreases of about 2.5 mv/ o C
20 Transition (or depletion) capacitance Due to variations in the width of the depletion layer -> variations of the charge
21 Diffusion capacitance Due to variations in the profile of the carriers in the proximity of the depletion layer The extra charge in the profile of the carriers concentrations, close to the space charge region, is proportional to J: The corresponding capacitive effect is also proportional to J:
22 Diodes and switching [See spice Simulation]
23 Large signal model So the large signal model of a diode is -> All these 3 parameters (1 conductance and 2 capacitors) change with bias In inverse bias C j prevails on C d the opposite in direct bias
24 Small signal model By linearising the model around the bias point we obtain the small signal model -> g d0 =I/hV T where I is the bias current It is a linear model!
25 Zener diodes All diodes are subject to breakdown for sufficiently high inverse bias Zener diodes are designed to work in this condition, normally as voltage references Two physical mechanisms: tunnel and avalanche Higher doping => thinner depletion region => higher E => easier breakdown => lower V z In order to have higher V z : lower doping (at least on one side)
26 Tunnel and avalanche breakdown Tunnel: for V Z <6V, high doping; V Z decreases with T Avalanche: for V Z >6V, lower doping; V Z increases with T
27 Photodiodes If suitable photons reach the junction, they may generate electron-hole couples minority (and also majority) concentrations will increase In reverse bias, current will be larger due to an extra photo-generated current I S proportional to the # of photons and we have I = -I S + I 0 (expv/v T -1) I V Photodiodes can be used as light detectors I Considering the opposite current (I =-I) V
28 Photodiodes as power generators I So we have an open circuit voltage (photovoltaic effect) I V and a short circuit current V I And we can also extract power! V Photovoltaic cells are diodes with very large area (to get many photons), optimized for power generation V I
29 LEDs
30 LEDs [Please note: the right drawing is deceitful, electron and holes are on the lines, not above or below the lines]
31 Heterojunctions E G ~1.4 ev for GaAs E G ~1.7 ev for AlGaAs 1. Isolated semiconductors 2. Ideally, immediately after junction creation 3. At thermal equilibrium (1) (2) (3)
Session 6: Solid State Physics. Diode
Session 6: Solid State Physics Diode 1 Outline A B C D E F G H I J 2 Definitions / Assumptions Homojunction: the junction is between two regions of the same material Heterojunction: the junction is between
More informationChapter 7. The pn Junction
Chapter 7 The pn Junction Chapter 7 PN Junction PN junction can be fabricated by implanting or diffusing donors into a P-type substrate such that a layer of semiconductor is converted into N type. Converting
More informationSemiconductor Physics and Devices
The pn Junction 1) Charge carriers crossing the junction. 3) Barrier potential Semiconductor Physics and Devices Chapter 8. The pn Junction Diode 2) Formation of positive and negative ions. 4) Formation
More informationEffective masses in semiconductors
Effective masses in semiconductors The effective mass is defined as: In a solid, the electron (hole) effective mass represents how electrons move in an applied field. The effective mass reflects the inverse
More informationSemiconductor Physics. Lecture 6
Semiconductor Physics Lecture 6 Recap pn junction and the depletion region Driven by the need to have no gradient in the fermi level free carriers migrate across the pn junction leaving a region with few
More informationMTLE-6120: Advanced Electronic Properties of Materials. Semiconductor p-n junction diodes. Reading: Kasap ,
MTLE-6120: Advanced Electronic Properties of Materials 1 Semiconductor p-n junction diodes Reading: Kasap 6.1-6.5, 6.9-6.12 Metal-semiconductor contact potential 2 p-type n-type p-type n-type Same semiconductor
More informationn N D n p = n i p N A
Summary of electron and hole concentration in semiconductors Intrinsic semiconductor: E G n kt i = pi = N e 2 0 Donor-doped semiconductor: n N D where N D is the concentration of donor impurity Acceptor-doped
More informationSemiconductor Junctions
8 Semiconductor Junctions Almost all solar cells contain junctions between different materials of different doping. Since these junctions are crucial to the operation of the solar cell, we will discuss
More informationPN Junctions. Lecture 7
Lecture 7 PN Junctions Kathy Aidala Applied Physics, G2 Harvard University 10 October, 2002 Wei 1 Active Circuit Elements Why are they desirable? Much greater flexibility in circuit applications. What
More informationFinal Examination EE 130 December 16, 1997 Time allotted: 180 minutes
Final Examination EE 130 December 16, 1997 Time allotted: 180 minutes Problem 1: Semiconductor Fundamentals [30 points] A uniformly doped silicon sample of length 100µm and cross-sectional area 100µm 2
More informationSemiconductor Physics fall 2012 problems
Semiconductor Physics fall 2012 problems 1. An n-type sample of silicon has a uniform density N D = 10 16 atoms cm -3 of arsenic, and a p-type silicon sample has N A = 10 15 atoms cm -3 of boron. For each
More informationSchottky Rectifiers Zheng Yang (ERF 3017,
ECE442 Power Semiconductor Devices and Integrated Circuits Schottky Rectifiers Zheng Yang (ERF 3017, email: yangzhen@uic.edu) Power Schottky Rectifier Structure 2 Metal-Semiconductor Contact The work function
More informationL03: pn Junctions, Diodes
8/30/2012 Page 1 of 5 Reference:C:\Users\Bernhard Boser\Documents\Files\Lib\MathCAD\Default\defaults.mcd L03: pn Junctions, Diodes Intrinsic Si Q: What are n, p? Q: Is the Si charged? Q: How could we make
More informationElectron Energy, E E = 0. Free electron. 3s Band 2p Band Overlapping energy bands. 3p 3s 2p 2s. 2s Band. Electrons. 1s ATOM SOLID.
Electron Energy, E Free electron Vacuum level 3p 3s 2p 2s 2s Band 3s Band 2p Band Overlapping energy bands Electrons E = 0 1s ATOM 1s SOLID In a metal the various energy bands overlap to give a single
More informationConsider a uniformly doped PN junction, in which one region of the semiconductor is uniformly doped with acceptor atoms and the adjacent region is
CHAPTER 7 The PN Junction Consider a uniformly doped PN junction, in which one region of the semiconductor is uniformly doped with acceptor atoms and the adjacent region is uniformly doped with donor atoms.
More informationECE 340 Lecture 27 : Junction Capacitance Class Outline:
ECE 340 Lecture 27 : Junction Capacitance Class Outline: Breakdown Review Junction Capacitance Things you should know when you leave M.J. Gilbert ECE 340 Lecture 27 10/24/11 Key Questions What types of
More informationThis is the 15th lecture of this course in which we begin a new topic, Excess Carriers. This topic will be covered in two lectures.
Solid State Devices Dr. S. Karmalkar Department of Electronics and Communication Engineering Indian Institute of Technology, Madras Lecture - 15 Excess Carriers This is the 15th lecture of this course
More informationAvalanche breakdown. Impact ionization causes an avalanche of current. Occurs at low doping
Avalanche breakdown Impact ionization causes an avalanche of current Occurs at low doping Zener tunneling Electrons tunnel from valence band to conduction band Occurs at high doping Tunneling wave decays
More informationPHYSICAL ELECTRONICS(ECE3540) CHAPTER 9 METAL SEMICONDUCTOR AND SEMICONDUCTOR HETERO-JUNCTIONS
PHYSICAL ELECTRONICS(ECE3540) CHAPTER 9 METAL SEMICONDUCTOR AND SEMICONDUCTOR HETERO-JUNCTIONS Tennessee Technological University Monday, November 11, 013 1 Introduction Chapter 4: we considered the semiconductor
More informationjunctions produce nonlinear current voltage characteristics which can be exploited
Chapter 6 P-N DODES Junctions between n-and p-type semiconductors are extremely important foravariety of devices. Diodes based on p-n junctions produce nonlinear current voltage characteristics which can
More informationV BI. H. Föll: kiel.de/matwis/amat/semi_en/kap_2/backbone/r2_2_4.html. different electrochemical potentials (i.e.
Consider the the band diagram for a homojunction, formed when two bits of the same type of semicondutor (e.g. Si) are doped p and ntype and then brought into contact. Electrons in the two bits have different
More informationElectronics The basics of semiconductor physics
Electronics The basics of semiconductor physics Prof. Márta Rencz, Gergely Nagy BME DED September 16, 2013 The basic properties of semiconductors Semiconductors conductance is between that of conductors
More informationFor the following statements, mark ( ) for true statement and (X) for wrong statement and correct it.
Benha University Faculty of Engineering Shoubra Electrical Engineering Department First Year communications. Answer all the following questions Illustrate your answers with sketches when necessary. The
More informationClassification of Solids
Classification of Solids Classification by conductivity, which is related to the band structure: (Filled bands are shown dark; D(E) = Density of states) Class Electron Density Density of States D(E) Examples
More informationSpring Semester 2012 Final Exam
Spring Semester 2012 Final Exam Note: Show your work, underline results, and always show units. Official exam time: 2.0 hours; an extension of at least 1.0 hour will be granted to anyone. Materials parameters
More informationCHAPTER 4: P-N P N JUNCTION Part 2. M.N.A. Halif & S.N. Sabki
CHAPTER 4: P-N P N JUNCTION Part 2 Part 2 Charge Storage & Transient Behavior Junction Breakdown Heterojunction CHARGE STORAGE & TRANSIENT BEHAVIOR Once injected across the junction, the minority carriers
More informationJunction Diodes. Tim Sumner, Imperial College, Rm: 1009, x /18/2006
Junction Diodes Most elementary solid state junction electronic devices. They conduct in one direction (almost correct). Useful when one converts from AC to DC (rectifier). But today diodes have a wide
More informationPeak Electric Field. Junction breakdown occurs when the peak electric field in the PN junction reaches a critical value. For the N + P junction,
Peak Electric Field Junction breakdown occurs when the peak electric field in the P junction reaches a critical value. For the + P junction, qa E ( x) ( xp x), s W dep 2 s ( bi Vr ) 2 s potential barrier
More informationLEC E T C U T R U E R E 17 -Photodetectors
LECTURE 17 -Photodetectors Topics to be covered Photodetectors PIN photodiode Avalanche Photodiode Photodetectors Principle of the p-n junction Photodiode A generic photodiode. Photodetectors Principle
More informationUNIVERSITY OF CALIFORNIA College of Engineering Department of Electrical Engineering and Computer Sciences. EECS 130 Professor Ali Javey Fall 2006
UNIVERSITY OF CALIFORNIA College of Engineering Department of Electrical Engineering and Computer Sciences EECS 130 Professor Ali Javey Fall 2006 Midterm 2 Name: SID: Closed book. Two sheets of notes are
More information1st Year-Computer Communication Engineering-RUC. 4- P-N Junction
4- P-N Junction We begin our study of semiconductor devices with the junction for three reasons. (1) The device finds application in many electronic systems, e.g., in adapters that charge the batteries
More informationQualitative Picture of the Ideal Diode. G.R. Tynan UC San Diego MAE 119 Lecture Notes
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
More informationElectronic Circuits for Mechatronics ELCT 609 Lecture 2: PN Junctions (1)
Electronic Circuits for Mechatronics ELCT 609 Lecture 2: PN Junctions (1) Assistant Professor Office: C3.315 E-mail: eman.azab@guc.edu.eg 1 Electronic (Semiconductor) Devices P-N Junctions (Diodes): Physical
More informationPhotodiodes and other semiconductor devices
Photodiodes and other semiconductor devices Chem 243 Winter 2017 What is a semiconductor? no e - Empty e levels Conduction Band a few e - Empty e levels Filled e levels Filled e levels lots of e - Empty
More informationp-n junction biasing, p-n I-V characteristics, p-n currents Norlaili Mohd. Noh EEE /09
CLASS 6&7 p-n junction biasing, p-n I-V characteristics, p-n currents 1 p-n junction biasing Unbiased p-n junction: the potential barrier is 0.7 V for Si and 0.3 V for Ge. Nett current across the p-n junction
More informationECE-305: Spring 2018 Exam 2 Review
ECE-305: Spring 018 Exam Review Pierret, Semiconductor Device Fundamentals (SDF) Chapter 3 (pp. 75-138) Chapter 5 (pp. 195-6) Professor Peter Bermel Electrical and Computer Engineering Purdue University,
More informationEE 3329 Electronic Devices Syllabus ( Extended Play )
EE 3329 - Electronic Devices Syllabus EE 3329 Electronic Devices Syllabus ( Extended Play ) The University of Texas at El Paso The following concepts can be part of the syllabus for the Electronic Devices
More informationECE 305 Exam 2: Spring 2017 March 10, 2017 Muhammad Alam Purdue University
NAME: PUID: : ECE 305 Exam 2: Spring 2017 March 10, 2017 Muhammad Alam Purdue University This is a closed book exam You may use a calculator and the formula sheet Following the ECE policy, the calculator
More informationSchottky Diodes (M-S Contacts)
Schottky Diodes (M-S Contacts) Three MITs of the Day Band diagrams for ohmic and rectifying Schottky contacts Similarity to and difference from bipolar junctions on electrostatic and IV characteristics.
More information1 Name: Student number: DEPARTMENT OF PHYSICS AND PHYSICAL OCEANOGRAPHY MEMORIAL UNIVERSITY OF NEWFOUNDLAND. Fall :00-11:00
1 Name: DEPARTMENT OF PHYSICS AND PHYSICAL OCEANOGRAPHY MEMORIAL UNIVERSITY OF NEWFOUNDLAND Final Exam Physics 3000 December 11, 2012 Fall 2012 9:00-11:00 INSTRUCTIONS: 1. Answer all seven (7) questions.
More informationSolid State Electronics. Final Examination
The University of Toledo EECS:4400/5400/7400 Solid State Electronic Section elssf08fs.fm - 1 Solid State Electronics Final Examination Problems Points 1. 1. 14 3. 14 Total 40 Was the exam fair? yes no
More informationEE105 Fall 2015 Microelectronic Devices and Circuits: Semiconductor Fabrication and PN Junctions
EE105 Fall 2015 Microelectronic Devices and Circuits: Semiconductor Fabrication and PN Junctions Prof. Ming C. Wu wu@eecs.berkeley.edu 511 Sutardja Dai Hall (SDH) 1 pn Junction p-type semiconductor in
More informationDiodes. anode. cathode. cut-off. Can be approximated by a piecewise-linear-like characteristic. Lecture 9-1
Diodes mplest nonlinear circuit element Basic operation sets the foundation for Bipolar Junction Transistors (BJTs) Also present in Field Effect Transistors (FETs) Ideal diode characteristic anode cathode
More informationSemiconductor Physics fall 2012 problems
Semiconductor Physics fall 2012 problems 1. An n-type sample of silicon has a uniform density N D = 10 16 atoms cm -3 of arsenic, and a p-type silicon sample has N A = 10 15 atoms cm -3 of boron. For each
More informationLecture 15 - The pn Junction Diode (I) I-V Characteristics. November 1, 2005
6.012 - Microelectronic Devices and Circuits - Fall 2005 Lecture 15-1 Lecture 15 - The pn Junction Diode (I) I-V Characteristics November 1, 2005 Contents: 1. pn junction under bias 2. I-V characteristics
More informationSemiconductor Physical Electronics
Semiconductor Physical Electronics Sheng S. Li Department of Electrical Engineering University of Florida Gainesville, Florida Plenum Press New York and London Contents CHAPTER 1. Classification of Solids
More informationSchottky diodes. JFETs - MESFETs - MODFETs
Technische Universität Graz Institute of Solid State Physics Schottky diodes JFETs - MESFETs - MODFETs Quasi Fermi level When the charge carriers are not in equilibrium the Fermi energy can be different
More informationForward-Active Terminal Currents
Forward-Active Terminal Currents Collector current: (electron diffusion current density) x (emitter area) diff J n AE qd n n po A E V E V th ------------------------------ e W (why minus sign? is by def.
More informationElectronic PRINCIPLES
MALVINO & BATES Electronic PRINCIPLES SEVENTH EDITION Chapter 2 Semiconductors Topics Covered in Chapter 2 Conductors Semiconductors Silicon crystals Intrinsic semiconductors Two types of flow Doping a
More informationEECS130 Integrated Circuit Devices
EECS130 Integrated Circuit Devices Professor Ali Javey 9/18/2007 P Junctions Lecture 1 Reading: Chapter 5 Announcements For THIS WEEK OLY, Prof. Javey's office hours will be held on Tuesday, Sept 18 3:30-4:30
More informationSheng S. Li. Semiconductor Physical Electronics. Second Edition. With 230 Figures. 4) Springer
Sheng S. Li Semiconductor Physical Electronics Second Edition With 230 Figures 4) Springer Contents Preface 1. Classification of Solids and Crystal Structure 1 1.1 Introduction 1 1.2 The Bravais Lattice
More informationLecture 12. Semiconductor Detectors - Photodetectors
Lecture 12 Semiconductor Detectors - Photodetectors Principle of the pn junction photodiode Absorption coefficient and photodiode materials Properties of semiconductor detectors The pin photodiodes Avalanche
More informationSolid State Physics SEMICONDUCTORS - IV. Lecture 25. A.H. Harker. Physics and Astronomy UCL
Solid State Physics SEMICONDUCTORS - IV Lecture 25 A.H. Harker Physics and Astronomy UCL 9.9 Carrier diffusion and recombination Suppose we have a p-type semiconductor, i.e. n h >> n e. (1) Create a local
More information(Refer Slide Time: 03:41)
Solid State Devices Dr. S. Karmalkar Department of Electronics and Communication Engineering Indian Institute of Technology, Madras Lecture - 25 PN Junction (Contd ) This is the 25th lecture of this course
More informationPHYSICAL ELECTRONICS(ECE3540) CHAPTER 9 METAL SEMICONDUCTOR AND SEMICONDUCTOR HETERO-JUNCTIONS
PHYSICAL ELECTRONICS(ECE3540) CHAPTER 9 METAL SEMICONDUCTOR AND SEMICONDUCTOR HETERO-JUNCTIONS Tennessee Technological University Wednesday, October 30, 013 1 Introduction Chapter 4: we considered the
More informationLecture 2. Introduction to semiconductors Structures and characteristics in semiconductors
Lecture 2 Introduction to semiconductors Structures and characteristics in semiconductors Semiconductor p-n junction Metal Oxide Silicon structure Semiconductor contact Literature Glen F. Knoll, Radiation
More informationLecture 12. Semiconductor devices
Lecture 12 Semiconductor devices Intrinsic and extrinsic semiconductors The density of ac9ve carriers is for electrons and for holes, respec9vely. The product of the two is This product is independent
More information8. Schottky contacts / JFETs
Technische Universität Graz Institute of Solid State Physics 8. Schottky contacts / JFETs Nov. 21, 2018 Technische Universität Graz Institute of Solid State Physics metal - semiconductor contacts Photoelectric
More informationElectronic Devices and Circuits Lecture 5 - p-n Junction Injection and Flow - Outline
6.012 - Electronic Devices and Circuits Lecture 5 - p-n Junction Injection and Flow - Outline Review Depletion approimation for an abrupt p-n junction Depletion charge storage and depletion capacitance
More informationCurrent mechanisms Exam January 27, 2012
Current mechanisms Exam January 27, 2012 There are four mechanisms that typically cause currents to flow: thermionic emission, diffusion, drift, and tunneling. Explain briefly which kind of current mechanisms
More informationan introduction to Semiconductor Devices
an introduction to Semiconductor Devices Donald A. Neamen Chapter 6 Fundamentals of the Metal-Oxide-Semiconductor Field-Effect Transistor Introduction: Chapter 6 1. MOSFET Structure 2. MOS Capacitor -
More informationSample Exam # 2 ECEN 3320 Fall 2013 Semiconductor Devices October 28, 2013 Due November 4, 2013
Sample Exam # 2 ECEN 3320 Fall 203 Semiconductor Devices October 28, 203 Due November 4, 203. Below is the capacitance-voltage curve measured from a Schottky contact made on GaAs at T 300 K. Figure : Capacitance
More informationHoles (10x larger). Diode currents proportional to minority carrier densities on each side of the depletion region: J n n p0 = n i 2
Part V. (40 pts.) A diode is composed of an abrupt PN junction with N D = 10 16 /cm 3 and N A =10 17 /cm 3. The diode is very long so you can assume the ends are at x =positive and negative infinity. 1.
More informationFundamentals of Semiconductor Physics
Fall 2007 Fundamentals of Semiconductor Physics 万 歆 Zhejiang Institute of Modern Physics xinwan@zimp.zju.edu.cn http://zimp.zju.edu.cn/~xinwan/ Transistor technology evokes new physics The objective of
More informationBasic Physics of 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
More informationB12: Semiconductor Devices
B12: Semiconductor Devices Example Sheet 2: Solutions Question 1 To get from eq. (5.70) of the notes to the expression given in the examples sheet, we simply invoke the relations n 0 p 0, n 0 n 0. In this
More informationMisan University College of Engineering Electrical Engineering Department. Exam: Final semester Date: 17/6/2017
Misan University College of Engineering Electrical Engineering Department Subject: Electronic I Class: 1 st stage Exam: Final semester Date: 17/6/2017 Examiner: Dr. Baqer. O. TH. Time: 3 hr. Note: Answer
More informationECE-342 Test 2 Solutions, Nov 4, :00-8:00pm, Closed Book (one page of notes allowed)
ECE-342 Test 2 Solutions, Nov 4, 2008 6:00-8:00pm, Closed Book (one page of notes allowed) Please use the following physical constants in your calculations: Boltzmann s Constant: Electron Charge: Free
More informationBand Alignment and Graded Heterostructures. Guofu Niu Auburn University
Band Alignment and Graded Heterostructures Guofu Niu Auburn University Outline Concept of electron affinity Types of heterojunction band alignment Band alignment in strained SiGe/Si Cusps and Notches at
More informationLecture 2. Introduction to semiconductors Structures and characteristics in semiconductors. Fabrication of semiconductor sensor
Lecture 2 Introduction to semiconductors Structures and characteristics in semiconductors Semiconductor p-n junction Metal Oxide Silicon structure Semiconductor contact Fabrication of semiconductor sensor
More informationUNIVERSITY OF CALIFORNIA College of Engineering Department of Electrical Engineering and Computer Sciences. EECS 130 Professor Ali Javey Fall 2006
UNIVERSITY OF CALIFORNIA College of Engineering Department of Electrical Engineering and Computer Sciences EECS 130 Professor Ali Javey Fall 2006 Midterm I Name: Closed book. One sheet of notes is allowed.
More informationLecture-4 Junction Diode Characteristics
1 Lecture-4 Junction Diode Characteristics Part-II Q: Aluminum is alloyed into n-type Si sample (N D = 10 16 cm 3 ) forming an abrupt junction of circular cross-section, with an diameter of 0.02 in. Assume
More informationPN Junction
P Junction 2017-05-04 Definition Power Electronics = semiconductor switches are used Analogue amplifier = high power loss 250 200 u x 150 100 u Udc i 50 0 0 50 100 150 200 250 300 350 400 i,u dc i,u u
More informationLecture 2. Introduction to semiconductors Structures and characteristics in semiconductors
Lecture 2 Introduction to semiconductors Structures and characteristics in semiconductors Semiconductor p-n junction Metal Oxide Silicon structure Semiconductor contact Literature Glen F. Knoll, Radiation
More information- A free electron in CB "meets" a hole in VB: the excess energy -> a photon energy.
5.4. Recombination and Minority Carrier Injection 5.4.1 Direct and Indirect Recombination A free electron in CB "meets" a hole in VB: the excess energy > a photon energy. Energy CB ψ cb (k cb ) ψ vb (k
More informationSemiconductor Detectors
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
More informationCourse overview. Me: Dr Luke Wilson. The course: Physics and applications of semiconductors. Office: E17 open door policy
Course overview Me: Dr Luke Wilson Office: E17 open door policy email: luke.wilson@sheffield.ac.uk The course: Physics and applications of semiconductors 10 lectures aim is to allow time for at least one
More informationMidterm I - Solutions
UNIVERSITY OF CALIFORNIA College of Engineering Department of Electrical Engineering and Computer Sciences EECS 130 Spring 2008 Professor Chenming Hu Midterm I - Solutions Name: SID: Grad/Undergrad: Closed
More informationSemiconductor Device Physics
1 emiconductor Device Physics Lecture 8 http://zitompul.wordpress.com 2 0 1 3 emiconductor Device Physics 2 M Contacts and chottky Diodes 3 M Contact The metal-semiconductor (M) contact plays a very important
More informationConductivity and Semi-Conductors
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
More informationThermionic emission vs. drift-diffusion vs. p-n junction
6.772/SMA5111 - Compound Semiconductors Lecture 4 - Carrier flow in heterojunctions - Outline A look at current models for m-s junctions (old business) Thermionic emission vs. drift-diffusion vs. p-n junction
More informationElectronic Devices & Circuits
Electronic Devices & Circuits For Electronics & Communication Engineering By www.thegateacademy.com Syllabus Syllabus for Electronic Devices Energy Bands in Intrinsic and Extrinsic Silicon, Carrier Transport,
More informationChemistry Instrumental Analysis Lecture 8. Chem 4631
Chemistry 4631 Instrumental Analysis Lecture 8 UV to IR Components of Optical Basic components of spectroscopic instruments: stable source of radiant energy transparent container to hold sample device
More information2.626 Fundamentals of Photovoltaics
MIT OpenCourseWare http://ocw.mit.edu 2.626 Fundamentals of Photovoltaics Fall 2008 For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms. Charge Separation:
More informationPN Junction and MOS structure
PN Junction and MOS structure Basic electrostatic equations We will use simple one-dimensional electrostatic equations to develop insight and basic understanding of how semiconductor devices operate Gauss's
More informationFYS3410 Condensed matter physics
FYS3410 Condensed matter physics Lecture 23 and 24: pn-junctions and electrooptics Randi Haakenaasen UniK/UiO Forsvarets forskningsinstitutt 11.05.2016 and 18.05.2016 Outline Why pn-junctions are important
More informationSemiconductor Physics. Lecture 3
Semiconductor Physics Lecture 3 Intrinsic carrier density Intrinsic carrier density Law of mass action Valid also if we add an impurity which either donates extra electrons or holes the number of carriers
More informationLecture (02) PN Junctions and Diodes
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
More informationSRI VIDYA COLLEGE OF ENGINEERING AND TECHNOLOGY VIRUDHUNAGAR Department of Electronics and Communication Engineering
SRI VIDYA COLLEGE OF ENGINEERING AND TECHNOLOGY VIRUDHUNAGAR Department of Electronics and Communication Engineering Class/Sem:I ECE/II Question Bank for EC6201-ELECTRONIC DEVICES 1.What do u meant by
More informationUNIT - IV SEMICONDUCTORS AND MAGNETIC MATERIALS
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
More information( )! N D ( x) ) and equilibrium
ECE 66: SOLUTIONS: ECE 66 Homework Week 8 Mark Lundstrom March 7, 13 1) The doping profile for an n- type silicon wafer ( N D = 1 15 cm - 3 ) with a heavily doped thin layer at the surface (surface concentration,
More informationSemiconductor Physics Problems 2015
Semiconductor Physics Problems 2015 Page and figure numbers refer to Semiconductor Devices Physics and Technology, 3rd edition, by SM Sze and M-K Lee 1. The purest semiconductor crystals it is possible
More informationInstitute of Solid State Physics. Technische Universität Graz. Exam. Feb 2, 10:00-11:00 P2
Technische Universität Graz nstitute of Solid State Physics Exam Feb 2, 10:00-11:00 P2 Exam Four questions, two from the online list. Calculator is ok. No notes. Explain some concept: (tunnel contact,
More informationThe photovoltaic effect occurs in semiconductors where there are distinct valence and
How a Photovoltaic Cell Works The photovoltaic effect occurs in semiconductors where there are distinct valence and conduction bands. (There are energies at which electrons can not exist within the solid)
More informationREVISED HIGHER PHYSICS REVISION BOOKLET ELECTRONS AND ENERGY
REVSED HGHER PHYSCS REVSON BOOKLET ELECTRONS AND ENERGY Kinross High School Monitoring and measuring a.c. Alternating current: Mains supply a.c.; batteries/cells supply d.c. Electrons moving back and forth,
More informationPHYS485 Materials Physics
5/11/017 PHYS485 Materials Physics Dr. Gregory W. Clar Manchester University LET S GO ON A (TEK)ADVENTURE! WHAT? TRIP TO A MAKER S SPACE IN FORT WAYNE WHEN? THURSDAY, MAY 11 TH @ 5PM WHERE? TEKVENTURE
More information3. Two-dimensional systems
3. Two-dimensional systems Image from IBM-Almaden 1 Introduction Type I: natural layered structures, e.g., graphite (with C nanostructures) Type II: artificial structures, heterojunctions Great technological
More informationLecture 19 - p-n Junction (cont.) October 18, Ideal p-n junction out of equilibrium (cont.) 2. pn junction diode: parasitics, dynamics
6.720J/3.43J - Integrated Microelectronic Devices - Fall 2002 Lecture 19-1 Lecture 19 - p-n Junction (cont.) October 18, 2002 Contents: 1. Ideal p-n junction out of equilibrium (cont.) 2. pn junction diode:
More informationITT Technical Institute ET215 Devices I Unit 1
ITT Technical Institute ET215 Devices I Unit 1 Chapter 1 Chapter 2, Sections 2.1-2.4 Chapter 1 Basic Concepts of Analog Circuits Recall ET115 & ET145 Ohms Law I = V/R If voltage across a resistor increases
More informationSurfaces, Interfaces, and Layered Devices
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
More information