Part 1: MetalMetal Contacts Workfunction Differences Flat band (a) (Pt) = 5.36 ev Pt Vacuum Fermi level Electrons Mo Vacuum Fermi level Electrons (Mo)

Size: px
Start display at page:

Download "Part 1: MetalMetal Contacts Workfunction Differences Flat band (a) (Pt) = 5.36 ev Pt Vacuum Fermi level Electrons Mo Vacuum Fermi level Electrons (Mo)"

Transcription

1 Applications Using Band Diagrams and Fermi Energy Level Applications to Devices Physics Physics Homojunctions Heterojunctions pn junction metals/c junctions diodes pnp junction pnp Bipolar transistors & Light Emitting Devices Metaloxidesemiconductor junction MOS capacitors MOS transistors 1 1

2 Part 1: MetalMetal Contacts Workfunction Differences Flat band (a) (Pt) = 5.36 ev Pt Vacuum Fermi level Electrons Mo Vacuum Fermi level Electrons (Mo) = 4.20 ev E vac s aligned (Pt) (Mo) = 1.16 ev = ev Vacuum Equilibrium (b) 5.36 ev Fermi level Vacuum 4.20 ev E f s aligned Fig. 4.28: When two metals are brought together, there is a contact potential, V. (a) Electrons are more energetic in Mo so they tunnel to the surface of Pt. (b) Equilibrium is reached when the Fermi levels are lined up. From Principles of Electronic Materials and Devices, Second Edition, S.O. Kasap ( McGrawHill, 2002) 2 2

3 Workfunctions of Various Metals Workfunction Equation as Determined by Mehrotra & Mahanty a o = Bohr radius p = plasmon frequency = numerical value for integral = (1/3) 0.5 v f v f = Fermi velocity r o = radius of equilibrium density distribution of free electrons Mehrotra & Mahanty, Free electron contribution to the workfunction of metals, J. Phys. C: Solid State Phys., Vol. 11,

4 Workfunctions of Various Metals CRC?; 4 4

5 Image Potential = Schottky Effect E E work vacuum F Image PE E F E vacuum Applied PE Net PE E F E F eff 2 e VTotal () r E vacuum er 16 r Image Force Potential Energy: an e a distance r from a metal surface that has a potential energy, V image. V image 2 e () r 16r E f 0 V () r E image x vacuum 2 e 16r (a) (b) (c) Fig. 4.36: (a) PE of the electron near the surface of a conductor, (b) Electron PE due to an applied field e.g. between cathode and anode (c) The overall PE is the sum. V x Vapplied () r er electric field VTotal () r r rrmin 0 x To find eff : Need to find maximum: Take derivative and set = 0 Find r min. Substitute r min back into equation and solve for eff. max e eff From Principles of Electronic Materials and Devices, Second Edition, S.O. Kasap ( McGrawHill, 2002) p Ng, p

6 Field Emission & Image Force PE(x) E F eff V o (a) E F V max e eff e E F 0 0 x F Metal Vacuum (c) x Cathode x = 0 x = x F From Principles of Electronic Materials and Devices, Second Edition, S.O. Kasap ( McGrawHill, 2002) E (b) Grid or Anode FieldAssisted Thermionic Emission J e where: 3 e e eff e 4 o HV V electric field Fig (a) Field emission is the tunneling of an electron at an energy EF through the narrow PE barrier induced by a large applied field. (b) For simplicity we take the barrier to be rectangular. (c) A sharp point cathode has the maximumfield at the tip where the fieldemission of electrons occurs. e Vmax kt eeff kt 6 6

7 MetalMetal Contacts Seebeck Effect Seebeck effect (thermoelectric power) Builtin potential difference, ΔV, across a material due to a temperature difference, ΔT, across it S V T Sign of S: potential of the cold side with respect to the hot side; neg. if e s have accumulated in the cold side. Kasap, Electronic Materials & Devices (McGrawHill, 2006) Ch

8 Seebeck Effect e.g.: Cu, Li, Au Density of States = Low at E f Phonon Scattering will have a greater effect on electrons L hot < L cold (L = e mean free path) Density of States = High at E f Phonon Scattering will have a lesser effect on electrons L hot > L cold (L = e mean free path) e.g.: Ni, Pt, Al, Pd Fig 4.61 From Principles of Electronic Materials and Devices, Third Edition, S.O. Kasap ( McGrawHill, 2005) 8 8

9 Hot MetalMetal Contacts Seebeck Effect Application = Thermocouple Metal Cold Hot Metal type A Cold Metal 100 o C 0 V 0 o C Metal Metal type B 100 o C 0 o C 0 V Metal type B (a) Fig 4.32 (a) If same metal wires are used to measure the Seebeck voltage across the metal rod, then the net emf is zero. (b)the thermocouple from two different metals, type A and B. The cold end is maintained at 0 C which is the reference temperature. The other junction is used to sense the temperature. In this example it is heated to 100 C. T T V AB T o SA SBdT From Principles of Electronic Materials and Devices, Third Edition, S.O. Kasap ( McGrawHill, 2005) T o S AB (b) Number of Carriers Diffusing to Hot Region will differ in each metal, thus voltage difference occurs dt 9 9

10 MSE 410ECE 340 MetalS/C Contacts: Schottky & Ohmic Contacts Flat band R.F. Pierret, Semiconductor Device Fundamentals (AddisonWesley, 1996) Ch

11 MetalS/C Contacts: Schottky & Ohmic Contacts Flat band Flat band Equilibrium Equilibrium R.F. Pierret, Semiconductor Device Fundamentals (AddisonWesley, 1996) Ch

12 MetalS/C Contacts: Schottky & Ohmic Contacts BandBending Where does it come from? D A q pn nn d dx where o R 2 dv dx 2 d dx Poisson's Equation R.F. Pierret, Semiconductor Device Fundamentals (AddisonWesley, 1996) Ch

13 MetalS/C Contacts: Schottky & Ohmic Contacts Biasing Effects R.F. Pierret, Semiconductor Device Fundamentals (AddisonWesley, 1996) Ch

14 MetalS/C Contacts: Schottky & Ohmic Contacts Doping Effects Equilibrium R.F. Pierret, Semiconductor Device Fundamentals (AddisonWesley, 1996) Ch

15 Overview Equilibrium MetalS/C Contacts: Schottky & Ohmic Contacts Note: Blocking = Schottky Muller & Kamins, Device Electronics for Integrated Circuits, 3 rd Ed. (Wiley, 1996) Ch

Current mechanisms Exam January 27, 2012

Current 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 information

Schottky diodes. JFETs - MESFETs - MODFETs

Schottky 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 information

Semiconductor Device Physics

Semiconductor 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 information

Review Energy Bands Carrier Density & Mobility Carrier Transport Generation and Recombination

Review Energy Bands Carrier Density & Mobility Carrier Transport Generation and Recombination Review Energy Bands Carrier Density & Mobility Carrier Transport Generation and Recombination The Metal-Semiconductor Junction: Review Energy band diagram of the metal and the semiconductor before (a)

More information

Lecture 9: Metal-semiconductor junctions

Lecture 9: Metal-semiconductor junctions Lecture 9: Metal-semiconductor junctions Contents 1 Introduction 1 2 Metal-metal junction 1 2.1 Thermocouples.......................... 2 3 Schottky junctions 4 3.1 Forward bias............................

More information

8. Schottky contacts / JFETs

8. 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 information

- A free electron in CB "meets" a hole in VB: the excess energy -> a photon energy.

- 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 information

Avalanche 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 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 information

PHYSICAL ELECTRONICS(ECE3540) CHAPTER 9 METAL SEMICONDUCTOR AND SEMICONDUCTOR HETERO-JUNCTIONS

PHYSICAL 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 information

3. Two-dimensional systems

3. 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 information

Sheng 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 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 information

EECS130 Integrated Circuit Devices

EECS130 Integrated Circuit Devices EECS130 Integrated Circuit Devices Professor Ali Javey 10/02/2007 MS Junctions, Lecture 2 MOS Cap, Lecture 1 Reading: finish chapter14, start chapter16 Announcements Professor Javey will hold his OH at

More information

Physics of Semiconductors 8 th

Physics of Semiconductors 8 th Physics of Semiconductors 8 th 2016.6.6 Shingo Katsumoto Department of Physics, Institute for Solid State Physics University of Tokyo Review of pn junction Estimation of builtin potential Depletion layer

More information

Consider a uniformly doped PN junction, in which one region of the semiconductor is uniformly doped with acceptor atoms and the adjacent region is

Consider 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 information

PHYSICAL ELECTRONICS(ECE3540) CHAPTER 9 METAL SEMICONDUCTOR AND SEMICONDUCTOR HETERO-JUNCTIONS

PHYSICAL 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 information

Chapter 7. The pn Junction

Chapter 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 information

Final Examination EE 130 December 16, 1997 Time allotted: 180 minutes

Final 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 information

ECE 340 Lecture 35 : Metal- Semiconductor Junctions Class Outline:

ECE 340 Lecture 35 : Metal- Semiconductor Junctions Class Outline: ECE 340 Lecture 35 : - Junctions Class Outline: Ideal - Contacts Rectifying Contacts Ohmic Contacts Things you should know when you leave Key Questions What happens to the bands when we make contact between

More information

Semiconductor Physical Electronics

Semiconductor 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 information

Schottky Rectifiers Zheng Yang (ERF 3017,

Schottky 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 information

Effective masses in semiconductors

Effective 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 information

CMOS Devices. PN junctions and diodes NMOS and PMOS transistors Resistors Capacitors Inductors Bipolar transistors

CMOS Devices. PN junctions and diodes NMOS and PMOS transistors Resistors Capacitors Inductors Bipolar transistors CMOS Devices PN junctions and diodes NMOS and PMOS transistors Resistors Capacitors Inductors Bipolar transistors PN Junctions Diffusion causes depletion region D.R. is insulator and establishes barrier

More information

1 Name: Student number: DEPARTMENT OF PHYSICS AND PHYSICAL OCEANOGRAPHY MEMORIAL UNIVERSITY OF NEWFOUNDLAND. Fall :00-11:00

1 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 information

Conductivity and Semi-Conductors

Conductivity 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 information

MSE 310/ECE 340: Electrical Properties of Materials Fall 2014 Department of Materials Science and Engineering Boise State University

MSE 310/ECE 340: Electrical Properties of Materials Fall 2014 Department of Materials Science and Engineering Boise State University MSE 310/ECE 340: Electrical Properties of Materials Fall 2014 Department of Materials Science and Engineering Boise State University Practice Final Exam 1 Read the questions carefully Label all figures

More information

MENA9510 characterization course: Capacitance-voltage (CV) measurements

MENA9510 characterization course: Capacitance-voltage (CV) measurements MENA9510 characterization course: Capacitance-voltage (CV) measurements 30.10.2017 Halvard Haug Outline Overview of interesting sample structures Ohmic and schottky contacts Why C-V for solar cells? The

More information

Figure 3.1 (p. 141) Figure 3.2 (p. 142)

Figure 3.1 (p. 141) Figure 3.2 (p. 142) Figure 3.1 (p. 141) Allowed electronic-energy-state systems for two isolated materials. States marked with an X are filled; those unmarked are empty. System 1 is a qualitative representation of a metal;

More information

Semiconductor Junctions

Semiconductor 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 information

Fundamentals of Semiconductor Physics

Fundamentals 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 information

ECE335F: Electronic Devices Syllabus. Lecture*

ECE335F: Electronic Devices Syllabus. Lecture* Lecture 1 - Introduction: Course Overview 1 - Introduction: Course Overview 2 1 Crystal Structure of Solids 2 1 Crystal Structure of Solids 1.1 Semiconductor materials 1.1 Semiconductor materials 1.2 Types

More information

Metal Semiconductor Contacts

Metal Semiconductor Contacts Metal Semiconductor Contacts The investigation of rectification in metal-semiconductor contacts was first described by Braun [33-35], who discovered in 1874 the asymmetric nature of electrical conduction

More information

Schottky Diodes (M-S Contacts)

Schottky 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 information

The discussion about p-n junctions in the semiconductor device is fundamental both

The discussion about p-n junctions in the semiconductor device is fundamental both CHAPTER II MATERIALS JUNCTIONS 2.1 p-n Junctions 2.1.1 Homojunction The discussion about p-n junctions in the semiconductor device is fundamental both in modern electronic applications and in understanding

More information

Semiconductor device structures are traditionally divided into homojunction devices

Semiconductor device structures are traditionally divided into homojunction devices 0. Introduction: Semiconductor device structures are traditionally divided into homojunction devices (devices consisting of only one type of semiconductor material) and heterojunction devices (consisting

More information

The Devices: MOS Transistors

The Devices: MOS Transistors The Devices: MOS Transistors References: Semiconductor Device Fundamentals, R. F. Pierret, Addison-Wesley Digital Integrated Circuits: A Design Perspective, J. Rabaey et.al. Prentice Hall NMOS Transistor

More information

EE 130 Intro to MS Junctions Week 6 Notes. What is the work function? Energy to excite electron from Fermi level to the vacuum level

EE 130 Intro to MS Junctions Week 6 Notes. What is the work function? Energy to excite electron from Fermi level to the vacuum level EE 13 Intro to S Junctions eek 6 Notes Problem 1 hat is the work function? Energy to ecite electron from Fermi level to the vacuum level Electron affinity of 4.5eV Electron affinity of Ge 4.eV orkfunction

More information

Lecture 7: Electron Emission

Lecture 7: Electron Emission Lecture 7: Electron Emission Solid state physics of metals E_f > E_c --> Many conduction carriers E_f - Fermi level E_c - minimum conduction band energy A realistic potential well in a metal crystal An

More information

Semiconductor Physics and Devices

Semiconductor 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 information

Course overview. Me: Dr Luke Wilson. The course: Physics and applications of semiconductors. Office: E17 open door policy

Course 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 information

Thermionic emission vs. drift-diffusion vs. p-n junction

Thermionic 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 information

Appendix 1: List of symbols

Appendix 1: List of symbols Appendix 1: List of symbols Symbol Description MKS Units a Acceleration m/s 2 a 0 Bohr radius m A Area m 2 A* Richardson constant m/s A C Collector area m 2 A E Emitter area m 2 b Bimolecular recombination

More information

Section 12: Intro to Devices

Section 12: Intro to Devices Section 12: Intro to Devices Extensive reading materials on reserve, including Robert F. Pierret, Semiconductor Device Fundamentals Bond Model of Electrons and Holes Si Si Si Si Si Si Si Si Si Silicon

More information

Semiconductor Module

Semiconductor Module Semiconductor Module Optics Seminar July 18, 2018 Yosuke Mizuyama, Ph.D. COMSOL, Inc. The COMSOL Product Suite Governing Equations Semiconductor Schrödinger Equation Semiconductor Optoelectronics, FD Semiconductor

More information

Introduction to Transistors. Semiconductors Diodes Transistors

Introduction to Transistors. Semiconductors Diodes Transistors Introduction to Transistors Semiconductors Diodes Transistors 1 Semiconductors Typical semiconductors, like silicon and germanium, have four valence electrons which form atomic bonds with neighboring atoms

More information

Institute of Solid State Physics. Technische Universität Graz. Exam. Feb 2, 10:00-11:00 P2

Institute 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 information

Operation and Modeling of. The MOS Transistor. Second Edition. Yannis Tsividis Columbia University. New York Oxford OXFORD UNIVERSITY PRESS

Operation and Modeling of. The MOS Transistor. Second Edition. Yannis Tsividis Columbia University. New York Oxford OXFORD UNIVERSITY PRESS Operation and Modeling of The MOS Transistor Second Edition Yannis Tsividis Columbia University New York Oxford OXFORD UNIVERSITY PRESS CONTENTS Chapter 1 l.l 1.2 1.3 1.4 1.5 1.6 1.7 Chapter 2 2.1 2.2

More information

ELEC 4700 Assignment #2

ELEC 4700 Assignment #2 ELEC 4700 Assignment #2 Question 1 (Kasop 4.2) Molecular Orbitals and Atomic Orbitals Consider a linear chain of four identical atoms representing a hypothetical molecule. Suppose that each atomic wavefunction

More information

Quantum Phenomena & Nanotechnology (4B5)

Quantum Phenomena & Nanotechnology (4B5) Quantum Phenomena & Nanotechnology (4B5) The 2-dimensional electron gas (2DEG), Resonant Tunneling diodes, Hot electron transistors Lecture 11 In this lecture, we are going to look at 2-dimensional electron

More information

ECE-305: Spring 2018 Exam 2 Review

ECE-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 information

Session 6: Solid State Physics. Diode

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 information

eterostrueture Integrated Thermionic Refrigeration

eterostrueture Integrated Thermionic Refrigeration eterostrueture Integrated Thermionic Refrigeration Ali Shakouri, and John E. Bowers Department of Electrical and Computer Engineering University of California, Santa Barbara, CA USA 936 ABSTRACT Thermionic

More information

Introduction to Power Semiconductor Devices

Introduction to Power Semiconductor Devices ECE442 Power Semiconductor Devices and Integrated Circuits Introduction to Power Semiconductor Devices Zheng Yang (ERF 3017, email: yangzhen@uic.edu) Power Semiconductor Devices Applications System Ratings

More information

n N D n p = n i p N A

n 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 information

Using a Mercury itc with thermocouples

Using a Mercury itc with thermocouples Technical Note Mercury Support Using a Mercury itc with thermocouples Abstract and content description This technical note describes how to make accurate and reliable temperature measurements using an

More information

R. Ludwig and G. Bogdanov RF Circuit Design: Theory and Applications 2 nd edition. Figures for Chapter 6

R. Ludwig and G. Bogdanov RF Circuit Design: Theory and Applications 2 nd edition. Figures for Chapter 6 R. Ludwig and G. Bogdanov RF Circuit Design: Theory and Applications 2 nd edition Figures for Chapter 6 Free electron Conduction band Hole W g W C Forbidden Band or Bandgap W V Electron energy Hole Valence

More information

Memories Bipolar Transistors

Memories Bipolar Transistors Technische Universität Graz nstitute of Solid State Physics Memories Bipolar Transistors Technische Universität Graz nstitute of Solid State Physics Exams February 5 March 7 April 18 June 27 Exam Four

More information

V BI. H. Föll: kiel.de/matwis/amat/semi_en/kap_2/backbone/r2_2_4.html. different electrochemical potentials (i.e.

V 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 information

Module 4 : THERMOELECTRICITY Lecture 21 : Seebeck Effect

Module 4 : THERMOELECTRICITY Lecture 21 : Seebeck Effect Module 4 : THERMOELECTRICITY Lecture 21 : Seebeck Effect Objectives In this lecture you will learn the following Seebeck effect and thermo-emf. Thermoelectric series of metals which can be used to form

More information

ECE321 Electronics I

ECE321 Electronics I ECE321 Electronics I Lecture 4: Physics of Semiconductor iodes Payman Zarkesh-Ha Office: ECE Bldg. 230B Office hours: Tuesday 2:00-3:00PM or by appointment E-mail: pzarkesh.unm.edu Slide: 1 Review of Last

More information

ECE 340 Lecture 27 : Junction Capacitance Class Outline:

ECE 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 information

CME 300 Properties of Materials. ANSWERS: Homework 9 November 26, As atoms approach each other in the solid state the quantized energy states:

CME 300 Properties of Materials. ANSWERS: Homework 9 November 26, As atoms approach each other in the solid state the quantized energy states: CME 300 Properties of Materials ANSWERS: Homework 9 November 26, 2011 As atoms approach each other in the solid state the quantized energy states: are split. This splitting is associated with the wave

More information

Transistors - a primer

Transistors - a primer ransistors - a primer What is a transistor? Solid-state triode - three-terminal device, with voltage (or current) at third terminal used to control current between other two terminals. wo types: bipolar

More information

For the following statements, mark ( ) for true statement and (X) for wrong statement and correct it.

For 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 information

A. OTHER JUNCTIONS B. SEMICONDUCTOR HETEROJUNCTIONS -- MOLECULES AT INTERFACES: ORGANIC PHOTOVOLTAIC BULK HETEROJUNCTION DYE-SENSITIZED SOLAR CELL

A. OTHER JUNCTIONS B. SEMICONDUCTOR HETEROJUNCTIONS -- MOLECULES AT INTERFACES: ORGANIC PHOTOVOLTAIC BULK HETEROJUNCTION DYE-SENSITIZED SOLAR CELL A. OTHER JUNCTIONS B. SEMICONDUCTOR HETEROJUNCTIONS -- MOLECULES AT INTERFACES: ORGANIC PHOTOVOLTAIC BULK HETEROJUNCTION DYE-SENSITIZED SOLAR CELL March 24, 2015 The University of Toledo, Department of

More information

Band Alignment and Graded Heterostructures. Guofu Niu Auburn University

Band 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 information

PN Junctions. Lecture 7

PN 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 information

Part 4: Heterojunctions - MOS Devices. MOSFET Current Voltage Characteristics

Part 4: Heterojunctions - MOS Devices. MOSFET Current Voltage Characteristics MOS Device Uses: Part 4: Heterojunctions - MOS Devices MOSCAP capacitor: storing charge, charge-coupled device (CCD), etc. MOSFET transistor: switch, current amplifier, dynamic random access memory (DRAM-volatile),

More information

Lecture 4 - PN Junction and MOS Electrostatics (I) Semiconductor Electrostatics in Thermal Equilibrium September 20, 2005

Lecture 4 - PN Junction and MOS Electrostatics (I) Semiconductor Electrostatics in Thermal Equilibrium September 20, 2005 6.012 - Microelectronic Devices and Circuits - Fall 2005 Lecture 4-1 Contents: Lecture 4 - PN Junction and MOS Electrostatics (I) Semiconductor Electrostatics in Thermal Equilibrium September 20, 2005

More information

Lecture 27: Introduction to Bipolar Transistors

Lecture 27: Introduction to Bipolar Transistors NCN www.nanohub.org ECE606: Solid State Devices Lecture 27: Introduction to ipolar Transistors Muhammad Ashraful Alam alam@purdue.edu Alam ECE 606 S09 1 ackground E C E C ase! Point contact Germanium transistor

More information

ECE-305: Fall 2017 Metal Oxide Semiconductor Devices

ECE-305: Fall 2017 Metal Oxide Semiconductor Devices C-305: Fall 2017 Metal Oxide Semiconductor Devices Pierret, Semiconductor Device Fundamentals (SDF) Chapters 15+16 (pp. 525-530, 563-599) Professor Peter Bermel lectrical and Computer ngineering Purdue

More information

Session 0: Review of Solid State Devices. From Atom to Transistor

Session 0: Review of Solid State Devices. From Atom to Transistor Session 0: Review of Solid State Devices From Atom to Transistor 1 Objective To Understand: how Diodes, and Transistors operate! p n p+ n p- n+ n+ p 2 21 Century Alchemy! Ohm s law resistivity Resistivity

More information

Sample Exam # 2 ECEN 3320 Fall 2013 Semiconductor Devices October 28, 2013 Due November 4, 2013

Sample 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 information

Semiconductor Physics. Lecture 3

Semiconductor 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 information

III.6. METAL SEMICONDUCTOR CONTACT BIAS

III.6. METAL SEMICONDUCTOR CONTACT BIAS .6. MEAL SEMCONUCOR CONAC BAS 1. Work purpose he determination of the potential difference that appears at the contact surface between a metal and a semiconductor, potential difference that is known under

More information

Section 12: Intro to Devices

Section 12: Intro to Devices Section 12: Intro to Devices Extensive reading materials on reserve, including Robert F. Pierret, Semiconductor Device Fundamentals EE143 Ali Javey Bond Model of Electrons and Holes Si Si Si Si Si Si Si

More information

Classification of Solids

Classification 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 information

Surfaces, Interfaces, and Layered Devices

Surfaces, 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

Charge Extraction. Lecture 9 10/06/2011 MIT Fundamentals of Photovoltaics 2.626/2.627 Fall 2011 Prof. Tonio Buonassisi

Charge Extraction. Lecture 9 10/06/2011 MIT Fundamentals of Photovoltaics 2.626/2.627 Fall 2011 Prof. Tonio Buonassisi Charge Extraction Lecture 9 10/06/2011 MIT Fundamentals of Photovoltaics 2.626/2.627 Fall 2011 Prof. Tonio Buonassisi 2.626/2.627 Roadmap You Are Here 2.626/2.627: Fundamentals Every photovoltaic device

More information

Semiconductor Physics fall 2012 problems

Semiconductor 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 information

3 Minority carrier profiles (the hyperbolic functions) Consider a

3 Minority carrier profiles (the hyperbolic functions) Consider a Microelectronic Devices and Circuits October 9, 013 - Homework #3 Due Nov 9, 013 1 Te pn junction Consider an abrupt Si pn + junction tat as 10 15 acceptors cm -3 on te p-side and 10 19 donors on te n-side.

More information

Lecture 19 - p-n Junction (cont.) October 18, Ideal p-n junction out of equilibrium (cont.) 2. pn junction diode: parasitics, dynamics

Lecture 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 information

Thermionic Emission Theory

Thermionic Emission Theory hapter 4. PN and Metal-Semiconductor Junction Thermionic Emiion Theory Energy band diagram of a Schottky contact with a forward bia V applied between the metal and the emiconductor. Electron concentration

More information

Clean Energy: Thermoelectrics and Photovoltaics. Akram Boukai Ph.D.

Clean Energy: Thermoelectrics and Photovoltaics. Akram Boukai Ph.D. Clean Energy: Thermoelectrics and Photovoltaics Akram Boukai Ph.D. Solar Energy Use Hydrocarbons vs. Photons Arabian Oil: 600 years Sun: 1.5 billion years The Sun can Power both Solar Cells and Thermoelectrics

More information

4.2 Molecular orbitals and atomic orbitals Consider a linear chain of four identical atoms representing a hypothetical molecule.

4.2 Molecular orbitals and atomic orbitals Consider a linear chain of four identical atoms representing a hypothetical molecule. 4. Molecular orbitals and atomic orbitals Consider a linear chain of four identical atoms representing a hypothetical molecule. Suppose that each atomic wavefunction is 1s wavefunction. This system of

More information

16EC401 BASIC ELECTRONIC DEVICES UNIT I PN JUNCTION DIODE. Energy Band Diagram of Conductor, Insulator and Semiconductor:

16EC401 BASIC ELECTRONIC DEVICES UNIT I PN JUNCTION DIODE. Energy Band Diagram of Conductor, Insulator and Semiconductor: 16EC401 BASIC ELECTRONIC DEVICES UNIT I PN JUNCTION DIODE Energy bands in Intrinsic and Extrinsic silicon: Energy Band Diagram of Conductor, Insulator and Semiconductor: 1 2 Carrier transport: Any motion

More information

MTLE-6120: Advanced Electronic Properties of Materials. Semiconductor p-n junction diodes. Reading: Kasap ,

MTLE-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 information

Solar Cell Materials and Device Characterization

Solar Cell Materials and Device Characterization Solar Cell Materials and Device Characterization April 3, 2012 The University of Toledo, Department of Physics and Astronomy SSARE, PVIC Principles and Varieties of Solar Energy (PHYS 4400) and Fundamentals

More information

Concepts & Equations. Applications: Devices

Concepts & Equations. Applications: Devices Concepts & Equations Applications: Devices Concepts & Equations Applications: Devices Current = (charge) x (velocity) Ch1-4 Ch5-6 Concepts & Equations Applications: Devices Concepts & Equations Ch1 Landscape

More information

an introduction to Semiconductor Devices

an 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 information

Metallic: 2n 1. +n 2. =3q Armchair structure always metallic = 2

Metallic: 2n 1. +n 2. =3q Armchair structure always metallic = 2 Properties of CNT d = 2.46 n 2 2 1 + n1n2 + n2 2π Metallic: 2n 1 +n 2 =3q Armchair structure always metallic a) Graphite Valence(π) and Conduction(π*) states touch at six points(fermi points) Carbon Nanotube:

More information

Part 5: Quantum Effects in MOS Devices

Part 5: Quantum Effects in MOS Devices Quantum Effects Lead to Phenomena such as: Ultra Thin Oxides Observe: High Leakage Currents Through the Oxide - Tunneling Depletion in Poly-Si metal gate capacitance effect Thickness of Inversion Layer

More information

The Law of the Junction Revisited. Mark Lundstrom Network for Computational Nanotechnology and Purdue University ( ). (1)

The Law of the Junction Revisited. Mark Lundstrom Network for Computational Nanotechnology and Purdue University ( ). (1) The Law of the Junction Revisited Mark Lundstrom Network for Computational Nanotechnology and Purdue University Consider a one-sided, short base diode like that shown in Fig.. We usually analyze the I-V

More information

Semiconductor Physical Electronics

Semiconductor Physical Electronics Semiconductor Physical Electronics Sheng S. Li Semiconductor Physical Electronics Second Edition With 230 Figures Sheng S. Li Department of Electrical and Computer Engineering University of Florida Gainesville,

More information

9. Semiconductor Devices /Phonons

9. Semiconductor Devices /Phonons Technische Universität Graz Institute of Solid State Physics 9. Semiconductor Devices /Phonons Oct 29, 2018 p and n profiles p n V bi ~ 1 V E c W ~ 1 m E F E max ~ 10 4 V/cm ev bi E v p Ev E F Nv exp kt

More information

Electrical Characteristics of MOS Devices

Electrical Characteristics of MOS Devices Electrical Characteristics of MOS Devices The MOS Capacitor Voltage components Accumulation, Depletion, Inversion Modes Effect of channel bias and substrate bias Effect of gate oide charges Threshold-voltage

More information

Spring Semester 2012 Final Exam

Spring 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 information

Sensing, Computing, Actuating

Sensing, Computing, Actuating Sensing, Computing, ctuating Sander Stuijk (s.stuijk@tue.nl) Department of Electrical Engineering Electronic Systems 2 THERMOELECTRIC EFFECT (Chapter 5.11) 3 Thermocouple cylinder head temperature (thermocouple)

More information

Lecture 12: MOS Capacitors, transistors. Context

Lecture 12: MOS Capacitors, transistors. Context Lecture 12: MOS Capacitors, transistors Context In the last lecture, we discussed PN diodes, and the depletion layer into semiconductor surfaces. Small signal models In this lecture, we will apply those

More information

Theory of Electrical Characterization of Semiconductors

Theory of Electrical Characterization of Semiconductors Theory of Electrical Characterization of Semiconductors P. Stallinga Universidade do Algarve U.C.E.H. A.D.E.E.C. OptoElectronics SELOA Summer School May 2000, Bologna (It) Overview Devices: bulk Schottky

More information

JFET/MESFET. JFET: small gate current (reverse leakage of the gate-to-channel junction) More gate leakage than MOSFET, less than bipolar.

JFET/MESFET. JFET: small gate current (reverse leakage of the gate-to-channel junction) More gate leakage than MOSFET, less than bipolar. JFET/MESFET JFET: small gate current (reverse leakage of the gate-to-channel junction) More gate leakage than MOSFET, less than bipolar. JFET has higher transconductance than the MOSFET. Used in low-noise,

More information