Diamond. Covalent Insulators and Semiconductors. Silicon, Germanium, Gray Tin. Chem 462 September 24, 2004
|
|
- Kristian Bell
- 5 years ago
- Views:
Transcription
1 Covalent Insulators and Chem 462 September 24, 2004 Diamond Pure sp 3 carbon All bonds staggered- ideal d(c-c) Å, like ethane Silicon, Germanium, Gray Tin Diamond structure Si and Ge: semiconductors Si is the purest element manufactured
2 Silicon and 3-5 Silicon (diamond-type) is related to the octet 3-5 semiconductors by replacing Si with, e.g., GaAs. Silicon vs. Carbon C-C single bonds (356 kj/mol) are much stronger than Si-Si bonds (230 kj/mol) occurrence of coal, hydrocarbons is reasonable no natural occurence of Si-Si bonds (can be synthesized, however) White Tin (β-sn) Stable under standard conditions, but unstable wrt a- Sn below 286 K at 1 atm pressure.
3 Crude picture for Bonding in Diamond Pick one carbon atom and look at its bonds to four neighbor atoms. Mix 4 sp 3 orbitals from central atom with one sp 3 orbital from each of the other 4. Get 8 new orbitals, 4 bonding and 4 antibonding. Bonding orbitals filled, antibonding empty. Why an insulator? A band gap exists between the filled Empty conduction band and unfilled orbitals. sp 3 -sp 3 antibonding Band gap energy Filled valence band sp 3 -sp 3 bonding The gap is big; the bonding (and antibonding) interactions are strong. Band Diagrams Metal Semiconductor Insulator
4 Insulators With a large band gap, a lot of energy is needed to promote an electron. Visible light photons too low in energy, so diamond is transparent. Electrons can t readily move through material, so no electrical conductivity. Similar idea for thermal conductivity - at normal T, only low energy excitation possible. Measuring the Band Gap Absorbance E g Wavelength E g If the band gap becomes small enough, some conductivity can be achieved. Band gaps: diamond: silicon: 580 kj/mol (l ~ 206 nm) 105 kj/mol (l ~ 1140 nm) germanium: 64 kj/mol (l ~ 1870 nm) Pure Si or Ge can conduct at high T or if exposed to light.
5 Thermal energy promote e s from heat (thermal equilibrium), gives (virtually Boltzmann-like) distribution of excited states where some electrons are promoted. When electrons have been promoted (heat, light), the material will begin to conduct. Intrinsic (pure, undoped) Moderate band gaps - conductivity is low but increases with temperature: [e][h] = K eq = e - G / RT = (e S / R)e - H / RT H E = E gap also [e] = [h] [e] = [h] (e S / 2R) e -Egap/ 2RT Conductivity is an activated process (E a = E gap /2) in a pure semiconductor. Plot lnσ vs. (1/T) to get slope = E gap /2 Metals vs Metals resistivities increase with T resistivities decrease with T However, note the huge difference in scales on these plots! Resistivities = ρ = 1/σ σ [e] = [h] Ge W Al Cu
6 Extrinsic (Doped) Pure elemental semiconductors (Si, Ge, etc.) can only be used for devices where light or heat can be supplied to promote electrons. More useful devices are made using doped semiconductors appropriate impurities are intentionally added to supply electrons (e.g., P) or holes (e.g., Al). n-type Dope with phosphorus. An electron is left-over after forming Si-P bonds. The added electrons are easily promoted from the donor levels at normal temperatures, so they can serve as charge carriers. Typical n-type devices contain on the order of % P. Phosphorus doped into Si Si P +
7 n-type Add e donor levels pure silicon Initially, valence band is full, conduction band is empty Added e s must go in conduction band Extent of conductivity depends on # of electrons added. p-type Dope with aluminum. Formation of Al-Si bonds steals an electron from Si. The holes allow places for electrons to move into within the valence band, so they serve as charge carriers Shallow impurity levels, as for n-type - electrons easily promoted at normal temperatures. Properties of n & p type differ slightly. Most devices contain combinations of both. p-type Remove e acceptor levels pure silicon Initially, valence band is full, conduction band is empty Removing e s leaves holes in valence band Number of electrons removed determines conductivity.
So why is sodium a metal? Tungsten Half-filled 5d band & half-filled 6s band. Insulators. Interaction of metals with light?
Bonding in Solids: Metals, Insulators, & CHEM 107 T. Hughbanks Delocalized bonding in Solids Think of a pure solid as a single, very large molecule. Use our bonding pictures to try to understand properties.
More informationLecture 1. OUTLINE Basic Semiconductor Physics. Reading: Chapter 2.1. Semiconductors Intrinsic (undoped) silicon Doping Carrier concentrations
Lecture 1 OUTLINE Basic Semiconductor Physics Semiconductors Intrinsic (undoped) silicon Doping Carrier concentrations Reading: Chapter 2.1 EE105 Fall 2007 Lecture 1, Slide 1 What is a Semiconductor? Low
More informationGa and P Atoms to Covalent Solid GaP
Ga and P Atoms to Covalent Solid GaP Band Gaps in Binary Group III-V Semiconductors Mixed Semiconductors Affect of replacing some of the As with P in GaAs Band Gap (ev) (nm) GaAs 1.35 919 (IR) GaP 2.24
More informationFree Electron Model for Metals
Free Electron Model for Metals Metals are very good at conducting both heat and electricity. A lattice of in a sea of electrons shared between all nuclei (moving freely between them): This is referred
More informationLecture 2. Semiconductor Physics. Sunday 4/10/2015 Semiconductor Physics 1-1
Lecture 2 Semiconductor Physics Sunday 4/10/2015 Semiconductor Physics 1-1 Outline Intrinsic bond model: electrons and holes Charge carrier generation and recombination Intrinsic semiconductor Doping:
More informationECE 335: Electronic Engineering Lecture 2: Semiconductors
Faculty of Engineering ECE 335: Electronic Engineering Lecture 2: Semiconductors Agenda Intrinsic Semiconductors Extrinsic Semiconductors N-type P-type Carrier Transport Drift Diffusion Semiconductors
More informationAtoms? All matters on earth made of atoms (made up of elements or combination of elements).
Chapter 1 Atoms? All matters on earth made of atoms (made up of elements or combination of elements). Atomic Structure Atom is the smallest particle of an element that can exist in a stable or independent
More informationFree Electron Model for Metals
Free Electron Model for Metals Metals are very good at conducting both heat and electricity. A lattice of in a sea of electrons shared between all nuclei (moving freely between them): This is referred
More informationSemiconductors 1. Explain different types of semiconductors in detail with necessary bond diagrams. Intrinsic semiconductors:
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
More informationCLASS 12th. Semiconductors
CLASS 12th Semiconductors 01. Distinction Between Metals, Insulators and Semi-Conductors Metals are good conductors of electricity, insulators do not conduct electricity, while the semiconductors have
More informationEngineering 2000 Chapter 8 Semiconductors. ENG2000: R.I. Hornsey Semi: 1
Engineering 2000 Chapter 8 Semiconductors ENG2000: R.I. Hornsey Semi: 1 Overview We need to know the electrical properties of Si To do this, we must also draw on some of the physical properties and we
More informationFirst-Hand Investigation: Modeling of Semiconductors
perform an investigation to model the behaviour of semiconductors, including the creation of a hole or positive charge on the atom that has lost the electron and the movement of electrons and holes in
More informationMat E 272 Lecture 25: Electrical properties of materials
Mat E 272 Lecture 25: Electrical properties of materials December 6, 2001 Introduction: Calcium and copper are both metals; Ca has a valence of +2 (2 electrons per atom) while Cu has a valence of +1 (1
More informationELECTRONIC I Lecture 1 Introduction to semiconductor. By Asst. Prof Dr. Jassim K. Hmood
ELECTRONIC I Lecture 1 Introduction to semiconductor By Asst. Prof Dr. Jassim K. Hmood SOLID-STATE ELECTRONIC MATERIALS Electronic materials generally can be divided into three categories: insulators,
More informationV = IR or R = V I. R = ρ l A
Metals and Semiconductors Ram Seshadri MRL 2031, x6129, seshadri@mrl.ucsb.edu Electrical resistance and Ohm s Law: If an electric current I (units of A, Ampère) flows through a conductor with resistance
More informationEECS143 Microfabrication Technology
EECS143 Microfabrication Technology Professor Ali Javey Introduction to Materials Lecture 1 Evolution of Devices Yesterday s Transistor (1947) Today s Transistor (2006) Why Semiconductors? Conductors e.g
More informationEECS130 Integrated Circuit Devices
EECS130 Integrated Circuit Devices Professor Ali Javey 8/30/2007 Semiconductor Fundamentals Lecture 2 Read: Chapters 1 and 2 Last Lecture: Energy Band Diagram Conduction band E c E g Band gap E v Valence
More informationEE495/695 Introduction to Semiconductors I. Y. Baghzouz ECE Department UNLV
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
More informationBasic Semiconductor Physics
6 Basic Semiconductor Physics 6.1 Introduction With this chapter we start with the discussion of some important concepts from semiconductor physics, which are required to understand the operation of solar
More informationSemiconductors. Semiconductors also can collect and generate photons, so they are important in optoelectronic or photonic applications.
Semiconductors Semiconducting materials have electrical properties that fall between true conductors, (like metals) which are always highly conducting and insulators (like glass or plastic or common ceramics)
More informationCharge Carriers in Semiconductor
Charge Carriers in Semiconductor To understand PN junction s IV characteristics, it is important to understand charge carriers behavior in solids, how to modify carrier densities, and different mechanisms
More informationEE 446/646 Photovoltaic Devices I. Y. Baghzouz
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
More informationLN 3 IDLE MIND SOLUTIONS
IDLE MIND SOLUTIONS 1. Let us first look in most general terms at the optical properties of solids with band gaps (E g ) of less than 4 ev, semiconductors by definition. The band gap energy (E g ) can
More informationEE143 Fall 2016 Microfabrication Technologies. Evolution of Devices
EE143 Fall 2016 Microfabrication Technologies Prof. Ming C. Wu wu@eecs.berkeley.edu 511 Sutardja Dai Hall (SDH) 1-1 Evolution of Devices Yesterday s Transistor (1947) Today s Transistor (2006) 1-2 1 Why
More informationCrystal Properties. MS415 Lec. 2. High performance, high current. ZnO. GaN
Crystal Properties Crystal Lattices: Periodic arrangement of atoms Repeated unit cells (solid-state) Stuffing atoms into unit cells Determine mechanical & electrical properties High performance, high current
More informationChapter 1 Overview of Semiconductor Materials and Physics
Chapter 1 Overview of Semiconductor Materials and Physics Professor Paul K. Chu Conductivity / Resistivity of Insulators, Semiconductors, and Conductors Semiconductor Elements Period II III IV V VI 2 B
More informationA semiconductor is an almost insulating material, in which by contamination (doping) positive or negative charge carriers can be introduced.
Semiconductor A semiconductor is an almost insulating material, in which by contamination (doping) positive or negative charge carriers can be introduced. Page 2 Semiconductor materials Page 3 Energy levels
More informationLecture 7: Extrinsic semiconductors - Fermi level
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
More informationELEMENTARY BAND THEORY
ELEMENTARY BAND THEORY PHYSICIST Solid state band Valence band, VB Conduction band, CB Fermi energy, E F Bloch orbital, delocalized n-doping p-doping Band gap, E g Direct band gap Indirect band gap Phonon
More informationIntroduction to Engineering Materials ENGR2000. Dr.Coates
Introduction to Engineering Materials ENGR2000 Chapter 18: Electrical Properties Dr.Coates 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
More informationMTLE-6120: Advanced Electronic Properties of Materials. Intrinsic and extrinsic semiconductors. Reading: Kasap:
MTLE-6120: Advanced Electronic Properties of Materials 1 Intrinsic and extrinsic semiconductors Reading: Kasap: 5.1-5.6 Band structure and conduction 2 Metals: partially filled band(s) i.e. bands cross
More informationECE 442. Spring, Lecture -2
ECE 442 Power Semiconductor Devices and Integrated circuits Spring, 2006 University of Illinois at Chicago Lecture -2 Semiconductor physics band structures and charge carriers 1. What are the types of
More informationSolid State Device Fundamentals
Solid State Device Fundamentals ENS 345 Lecture Course by Alexander M. Zaitsev alexander.zaitsev@csi.cuny.edu Tel: 718 982 2812 Office 4N101b 1 The free electron model of metals The free electron model
More informationLecture 2 Electrons and Holes in Semiconductors
EE 471: Transport Phenomena in Solid State Devices Spring 2018 Lecture 2 Electrons and Holes in Semiconductors Bryan Ackland Department of Electrical and Computer Engineering Stevens Institute of Technology
More informationELECTRONIC DEVICES AND CIRCUITS SUMMARY
ELECTRONIC DEVICES AND CIRCUITS SUMMARY Classification of Materials: Insulator: An insulator is a material that offers a very low level (or negligible) of conductivity when voltage is applied. Eg: Paper,
More informationECE 250 Electronic Devices 1. Electronic Device Modeling
ECE 250 Electronic Devices 1 ECE 250 Electronic Device Modeling ECE 250 Electronic Devices 2 Introduction to Semiconductor Physics You should really take a semiconductor device physics course. We can only
More informationCh. 2: Energy Bands And Charge Carriers In Semiconductors
Ch. 2: Energy Bands And Charge Carriers In Semiconductors Discrete energy levels arise from balance of attraction force between electrons and nucleus and repulsion force between electrons each electron
More informationCLASS 1 & 2 REVISION ON SEMICONDUCTOR PHYSICS. Reference: Electronic Devices by Floyd
CLASS 1 & 2 REVISION ON SEMICONDUCTOR PHYSICS Reference: Electronic Devices by Floyd 1 ELECTRONIC DEVICES Diodes, transistors and integrated circuits (IC) are typical devices in electronic circuits. All
More informationSemiconductor Device Physics
1 Semiconductor Device Physics Lecture 1 http://zitompul.wordpress.com 2 0 1 3 2 Semiconductor Device Physics Textbook: Semiconductor Device Fundamentals, Robert F. Pierret, International Edition, Addison
More informationECE 142: Electronic Circuits Lecture 3: Semiconductors
Faculty of Engineering ECE 142: Electronic Circuits Lecture 3: Semiconductors Agenda Intrinsic Semiconductors Extrinsic Semiconductors N-type P-type Carrier Transport Drift Diffusion Semiconductors A semiconductor
More informationEE 346: Semiconductor Devices. 02/08/2017 Tewodros A. Zewde 1
EE 346: Semiconductor Devices 02/08/2017 Tewodros A. Zewde 1 DOPANT ATOMS AND ENERGY LEVELS Without help the total number of carriers (electrons and holes) is limited to 2ni. For most materials, this is
More informationKey Questions. ECE 340 Lecture 6 : Intrinsic and Extrinsic Material I 9/10/12. Class Outline: Effective Mass Intrinsic Material
9/1/1 ECE 34 Lecture 6 : Intrinsic and Extrinsic Material I Class Outline: Things you should know when you leave Key Questions What is the physical meaning of the effective mass What does a negative effective
More informationChapter 12: Semiconductors
Chapter 12: Semiconductors Bardeen & Shottky January 30, 2017 Contents 1 Band Structure 4 2 Charge Carrier Density in Intrinsic Semiconductors. 6 3 Doping of Semiconductors 12 4 Carrier Densities in Doped
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 informationElectro - Principles I
Electro - Principles I Page 10-1 Atomic Theory It is necessary to know what goes on at the atomic level of a semiconductor so the characteristics of the semiconductor can be understood. In many cases a
More informationIntroduction to Semiconductor Physics. Prof.P. Ravindran, Department of Physics, Central University of Tamil Nadu, India
Introduction to Semiconductor Physics 1 Prof.P. Ravindran, Department of Physics, Central University of Tamil Nadu, India http://folk.uio.no/ravi/cmp2013 Review of Semiconductor Physics Semiconductor fundamentals
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 informationKATIHAL FİZİĞİ MNT-510
KATIHAL FİZİĞİ MNT-510 YARIİLETKENLER Kaynaklar: Katıhal Fiziği, Prof. Dr. Mustafa Dikici, Seçkin Yayıncılık Katıhal Fiziği, Şakir Aydoğan, Nobel Yayıncılık, Physics for Computer Science Students: With
More informationCHAPTER 18: Electrical properties
CHAPTER 18: Electrical properties ISSUES TO ADDRESS... How are electrical conductance and resistance characterized? What are the physical phenomena that distinguish conductors, semiconductors, and insulators?
More informationChem 241. Lecture 24. UMass Amherst Biochemistry... Teaching Initiative
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
More informationChem 241. Lecture 23. UMass Amherst Biochemistry... Teaching Initiative
Chem 241 Lecture 23 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
More informationReview of Semiconductor Fundamentals
ECE 541/ME 541 Microelectronic Fabrication Techniques Review of Semiconductor Fundamentals Zheng Yang (ERF 3017, email: yangzhen@uic.edu) Page 1 Semiconductor A semiconductor is an almost insulating material,
More informationelectronics fundamentals
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
More informationECE 340 Lecture 6 : Intrinsic and Extrinsic Material I Class Outline:
ECE 340 Lecture 6 : Intrinsic and Extrinsic Material I Class Outline: Effective Mass Intrinsic Material Extrinsic Material Things you should know when you leave Key Questions What is the physical meaning
More informationEE 346: Semiconductor Devices
EE 346: Semiconductor Devices Lecture - 6 02/06/2017 Tewodros A. Zewde 1 DENSTY OF STATES FUNCTON Since current is due to the flow of charge, an important step in the process is to determine the number
More informationCME 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 informationSemiconductor physics I. The Crystal Structure of Solids
Lecture 3 Semiconductor physics I The Crystal Structure of Solids 1 Semiconductor materials Types of solids Space lattices Atomic Bonding Imperfection and doping in SOLIDS 2 Semiconductor Semiconductors
More information12/10/09. Chapter 18: Electrical Properties. View of an Integrated Circuit. Electrical Conduction ISSUES TO ADDRESS...
Chapter 18: Electrical Properties ISSUES TO ADDRESS... How are electrical conductance and resistance characterized? What are the physical phenomena that distinguish? For metals, how is affected by and
More informationLecture 3b. Bonding Model and Dopants. Reading: (Cont d) Notes and Anderson 2 sections
Lecture 3b Bonding Model and Dopants Reading: (Cont d) Notes and Anderson 2 sections 2.3-2.7 The need for more control over carrier concentration Without help the total number of carriers (electrons and
More informationn i exp E g 2kT lnn i E g 2kT
HOMEWORK #10 12.19 For intrinsic semiconductors, the intrinsic carrier concentration n i depends on temperature as follows: n i exp E g 2kT (28.35a) or taking natural logarithms, lnn i E g 2kT (12.35b)
More informationEE301 Electronics I , Fall
EE301 Electronics I 2018-2019, Fall 1. Introduction to Microelectronics (1 Week/3 Hrs.) Introduction, Historical Background, Basic Consepts 2. Rewiev of Semiconductors (1 Week/3 Hrs.) Semiconductor materials
More informationENERGY BANDS AND GAPS IN SEMICONDUCTOR. Muhammad Hafeez Javed
ENERGY BANDS AND GAPS IN SEMICONDUCTOR Muhammad Hafeez Javed www.rmhjaved.com rmhjaved@gmail.com Out Line Introduction Energy band Classification of materials Direct and indirect band gap of SC Classification
More informationISSUES TO ADDRESS...
Chapter 12: Electrical Properties School of Mechanical Engineering Choi, Hae-Jin Materials Science - Prof. Choi, Hae-Jin Chapter 12-1 ISSUES TO ADDRESS... How are electrical conductance and resistance
More informationBasic cell design. Si cell
Basic cell design Si cell 1 Concepts needed to describe photovoltaic device 1. energy bands in semiconductors: from bonds to bands 2. free carriers: holes and electrons, doping 3. electron and hole current:
More informationRRB JE 2019 Electronics Materials (Conductor, Semiconductor and Insulator)
RRB JE 2019 Electronics Materials (Conductor, Semiconductor and Insulator) 05.02.2019 [1 ] 1. Nucleus is made of न भभक बन ह त ह : - a) Electrons and Protons b) Photons and neutrons c) Photons and neutrons
More informationDirect and Indirect Semiconductor
Direct and Indirect Semiconductor Allowed values of energy can be plotted vs. the propagation constant, k. Since the periodicity of most lattices is different in various direction, the E-k diagram must
More information3.1 Introduction to Semiconductors. Y. Baghzouz ECE Department UNLV
3.1 Introduction to Semiconductors Y. Baghzouz ECE Department UNLV Introduction In this lecture, we will cover the basic aspects of semiconductor materials, and the physical mechanisms which are at the
More informationChap. 11 Semiconductor Diodes
Chap. 11 Semiconductor Diodes Semiconductor diodes provide the best resolution for energy measurements, silicon based devices are generally used for charged-particles, germanium for photons. Scintillators
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 informationESE 372 / Spring 2013 / Lecture 5 Metal Oxide Semiconductor Field Effect Transistor
Metal Oxide Semiconductor Field Effect Transistor V G V G 1 Metal Oxide Semiconductor Field Effect Transistor We will need to understand how this current flows through Si What is electric current? 2 Back
More informationCHAPTER 2: ENERGY BANDS & CARRIER CONCENTRATION IN THERMAL EQUILIBRIUM. M.N.A. Halif & S.N. Sabki
CHAPTER 2: ENERGY BANDS & CARRIER CONCENTRATION IN THERMAL EQUILIBRIUM OUTLINE 2.1 INTRODUCTION: 2.1.1 Semiconductor Materials 2.1.2 Basic Crystal Structure 2.1.3 Basic Crystal Growth technique 2.1.4 Valence
More informationI. Introduction II. Solid State Physics Detection of Light Bernhard Brandl 1
Detection of Light I. Introduction II. Solid State Physics 4-2-2015 Detection of Light Bernhard Brandl 1 4-2-2015 Detection of Light Bernhard Brandl 2 Blabla Recommended 4-2-2015 Detection of Light Bernhard
More informationUnit IV Semiconductors Engineering Physics
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
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 informationSEMICONDUCTOR PHYSICS
SEMICONDUCTOR PHYSICS by Dibyendu Chowdhury Semiconductors The materials whose electrical conductivity lies between those of conductors and insulators, are known as semiconductors. Silicon Germanium Cadmium
More informationSemiconductors. SEM and EDAX images of an integrated circuit. SEM EDAX: Si EDAX: Al. Institut für Werkstoffe der ElektrotechnikIWE
SEM and EDAX images of an integrated circuit SEM EDAX: Si EDAX: Al source: [Cal 99 / 605] M&D-.PPT, slide: 1, 12.02.02 Classification semiconductors electronic semiconductors mixed conductors ionic conductors
More informationMicroscopic Ohm s Law
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.
More informationESE370: Circuit-Level Modeling, Design, and Optimization for Digital Systems
ESE370: Circuit-Level Modeling, Design, and Optimization for Digital Systems Lec 6: September 14, 2015 MOS Model You are Here: Transistor Edition! Previously: simple models (0 and 1 st order) " Comfortable
More informationReview of Optical Properties of Materials
Review of Optical Properties of Materials Review of optics Absorption in semiconductors: qualitative discussion Derivation of Optical Absorption Coefficient in Direct Semiconductors Photons When dealing
More informationHall effect in germanium
Hall effect in germanium Principle The resistance and Hall voltage are measured on rectangular pieces of germanium as a function of the doping of the crystal, temperature and of magnetic field. From the
More informationEXTRINSIC SEMICONDUCTOR
EXTRINSIC SEMICONDUCTOR EXTRINSIC SEMICONDUCTOR A semiconductor in which the impurity atoms are added by doping process is called Extrinsic semiconductor. The addition of impurities increases the carrier
More informationLECTURE 23. MOS transistor. 1 We need a smart switch, i.e., an electronically controlled switch. Lecture Digital Circuits, Logic
LECTURE 23 Lecture 16-20 Digital Circuits, Logic 1 We need a smart switch, i.e., an electronically controlled switch 2 We need a gain element for example, to make comparators. The device of our dreams
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 informationFrom Last Time Important new Quantum Mechanical Concepts. Atoms and Molecules. Today. Symmetry. Simple molecules.
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
More informationChap. 1 (Introduction), Chap. 2 (Components and Circuits)
CHEM 455 The class describes the principles and applications of modern analytical instruments. Emphasis is placed upon the theoretical basis of each type of instrument, its optimal area of application,
More informationSolid State Electronics EC210 Arab Academy for Science and Technology AAST Cairo Fall Lecture 10: Semiconductors
Solid State Electronics EC210 Arab Academy for Science and Technology AAST Cairo Fall 2014 Lecture 10: Semiconductors Lecture Notes Prepared by: Dr. Amr Bayoumi, Dr. Nadia Rafat These PowerPoint color
More informationsmal band gap Saturday, April 9, 2011
small band gap upper (conduction) band empty small gap valence band filled 2s 2p 2s 2p hybrid (s+p)band 2p no gap 2s (depend on the crystallographic orientation) extrinsic semiconductor semi-metal electron
More informationThe Semiconductor in Equilibrium
Lecture 6 Semiconductor physics IV The Semiconductor in Equilibrium Equilibrium, or thermal equilibrium No external forces such as voltages, electric fields. Magnetic fields, or temperature gradients are
More informationESE370: Circuit-Level Modeling, Design, and Optimization for Digital Systems
ESE370: Circuit-Level Modeling, Design, and Optimization for Digital Systems Lec 6: September 18, 2017 MOS Model You are Here: Transistor Edition! Previously: simple models (0 and 1 st order) " Comfortable
More informationDavid J. Starling Penn State Hazleton PHYS 214
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
More informationVariation of Energy Bands with Alloy Composition E
Variation of Energy Bands with Alloy Composition E 3.0 E.8.6 L 0.3eV Al x GaAs AlAs 1- xas 1.43eV.16eV X k.4 L. X.0 X 1.8 L 1.6 1.4 0 0. 0.4 0.6 X 0.8 1 1 Carriers in intrinsic Semiconductors Ec 4º 1º
More informationIntroduction 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 informationper unit cell Motif: Re at (0, 0, 0); 3O at ( 1 / 2, 0), (0, 0, 1 / 2 ) Re: 6 (octahedral coordination) O: 2 (linear coordination) ReO 6
Lattice: Primitive Cubic 1ReO 3 per unit cell Motif: Re at (0, 0, 0); 3O at ( 1 / 2, 0, 0), (0, 1 / 2, 0), (0, 0, 1 / 2 ) Re: 6 (octahedral coordination) O: 2 (linear coordination) ReO 6 octahedra share
More informationChapter 2. Electronics I - Semiconductors
Chapter 2 Electronics I - Semiconductors Fall 2017 talarico@gonzaga.edu 1 Charged Particles The operation of all electronic devices is based on controlling the flow of charged particles There are two type
More informatione - Galvanic Cell 1. Voltage Sources 1.1 Polymer Electrolyte Membrane (PEM) Fuel Cell
Galvanic cells convert different forms of energy (chemical fuel, sunlight, mechanical pressure, etc.) into electrical energy and heat. In this lecture, we are interested in some examples of galvanic cells.
More informationChapter 1 Semiconductor basics
Chapter 1 Semiconductor basics ELEC-H402/CH1: Semiconductor basics 1 Basic semiconductor concepts Semiconductor basics Semiconductors, silicon and hole-electron pair Intrinsic silicon properties Doped
More informationSemiconductor Detectors are Ionization Chambers. Detection volume with electric field Energy deposited positive and negative charge pairs
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
More informationHigher Physics. Electricity. Summary Notes. Monitoring and measuring a.c. Current, potential difference, power and resistance
Higher Physics Electricity Summary Notes Monitoring and measuring a.c. Current, potential difference, power and resistance Electrical sources and internal resistance Capacitors Conductors, semiconductors
More informationUNIVERSITY OF CALIFORNIA College of Engineering Department of Electrical Engineering and Computer Sciences. Professor Ali Javey. Spring 2009.
UNIVERSITY OF CALIFORNIA College of Engineering Department of Electrical Engineering and Computer Sciences EE143 Professor Ali Javey Spring 2009 Exam 1 Name: SID: Closed book. One sheet of notes is allowed.
More informationAdvantages / Disadvantages of semiconductor detectors
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
More information