Electronics I Lecture 1(b): Introduction to Electronics - University of
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Electronics I Lecture 1(b): Introduction to Electronics A/Lectr. Khalid Shakir Dept. Of Electrical Engineering College of Engineering Maysan University Copyright @2013 by Dept. of Electrical Engineering, Electronics I- Lecture 1(b)/1 st Semester 013/014 College of Engineering, Maysan University Page 1-15
Transcript of Electronics I Lecture 1(b): Introduction to Electronics - University of
Electronics ILecture 1(b): Introduction to Electronics
A/Lectr. Khalid ShakirDept. Of Electrical Engineering
College of EngineeringMaysan University
Copyright @2013 by Dept. of Electrical Engineering, Electronics I- Lecture 1(b)/1st Semester 013/014College of Engineering, Maysan University Page 1-15
Introduction to Electronics
© 2012 Pearson Education Inc.
Copyright @2013 by Dept. of Electrical Engineering, Electronics I- Lecture 1(b)/1st Semester 013/014College of Engineering, Maysan University Page 2-15
Electron Configurations
• This term shows thedistribution of allelectrons in an atom.
• Each componentconsists of– A number denoting the
energy level,
4p5
Introduction to Electronics
© 2012 Pearson Education Inc.
Copyright @2013 by Dept. of Electrical Engineering, Electronics I- Lecture 1(b)/1st Semester 013/014College of Engineering, Maysan University Page 3-15
• This term shows thedistribution of allelectrons in an atom
• Each componentconsists of– A number denoting the
energy level,– A letter denoting the type
of orbital,
4p5
Electron Configurations
Introduction to Electronics
© 2012 Pearson Education Inc.
Copyright @2013 by Dept. of Electrical Engineering, Electronics I- Lecture 1(b)/1st Semester 013/014College of Engineering, Maysan University Page 4-15
• This term shows thedistribution of allelectrons in an atom.
• Each componentconsists of– A number denoting the
energy level,– A letter denoting the type
of orbital,– A superscript denoting
the number of electronsin those orbitals.
4p5
Electron Configurations
© 2012 Pearson Education Inc.
Introduction to Electronics
Copyright @2013 by Dept. of Electrical Engineering, Electronics I- Lecture 1(b)/1st Semester 013/014College of Engineering, Maysan University Page 5-15
Electron Configurations
Primary Bonds: Chemical (strong) bonding, involves thetransfer or sharing of electrons.
There are three Primary or strong Bonds:
1- Metal to Non-Metal: Ionic Bond
2- Non-Metal to Non-Metal: Covalent Bond
3- Metal to Metal: Metallic Bond
© 2012 Pearson Education Inc.
Introduction to Electronics
Copyright @2013 by Dept. of Electrical Engineering, Electronics I- Lecture 1(b)/1st Semester 013/014College of Engineering, Maysan University Page 6-15
Chemical Bonding (Primary Bonds)
© 2012 Pearson Education Inc.
Introduction to Electronics
Copyright @2013 by Dept. of Electrical Engineering, Electronics I- Lecture 1(b)/1st Semester 013/014College of Engineering, Maysan University Page 7-15
Ionic Bonding
a type of chemical bonding that involves the electrostatic attractionbetween oppositely charged ions. These ions represent atoms that havelost one or more electron (known as cation) and atoms that have gainedone or more electrons (known as an anions). In the simplest case, thecation is a metal atom and the anion is a nonmetal atom.
Representation of ionic bondingbetween Lithium and Fluorine toform Lithium Fluoride.
Electrostatic interaction occursbetween the two resulting ions.
© 2012 Pearson Education Inc.
Introduction to Electronics
Copyright @2013 by Dept. of Electrical Engineering, Electronics I- Lecture 1(b)/1st Semester 013/014College of Engineering, Maysan University Page 8-15
Covalent Bonding
Covalent bonding is a bonding of twoor more atoms by the interaction oftheir valence electrons. Nonmetal tononmetal bonding.
© 2012 Pearson Education Inc.
Introduction to Electronics
Copyright @2013 by Dept. of Electrical Engineering, Electronics I- Lecture 1(b)/1st Semester 013/014College of Engineering, Maysan University Page 9-15
Metallic BondingA. Atoms in a metal are arranged in a
regular manner and vibrate about fixedpositions. The outermost electronsmove freely, forming a “sea ofelectrons” enveloping the positivemetal ions. The metal ions are attractedto and held together by the “sea ofelectrons”- these constitute metallicbonding. The movements of theelectrons are random under normalconditions.
B. C. & D. However, when a potentialdifference is applied across the metal, theelectrons move towards the direction of thepositive pole.
Introduction to Electronics
Copyright @2013 by Dept. of Electrical Engineering, Electronics I- Lecture 1(b)/1st Semester 013/014College of Engineering, Maysan University Page 10-15
Crystal Energy Band
Energy Band: also called “allowed band” is anenergy range in a solid where an electron states canexist.Energy Gap: also called “bandgap” is an energyrange in a solid where NO electron states can exist.
Conduction Band: is the range of electron energiesenough to free an electron from binding with its atomto move freely within the atomic lattice.
Valence Band: is the highest range of electronenergies in which electrons are normally present atabsolute zero temperature. Valence electrons arebound to individual atoms as opposed to conductionelectrons in conductors and semiconductors whichcan move freely within the atomic lattice.
© 2012 Pearson Education Inc.
Introduction to Electronics
Copyright @2013 by Dept. of Electrical Engineering, Electronics I- Lecture 1(b)/1st Semester 013/014College of Engineering, Maysan University
The valence shell determines the ability of material to conduct current.
A Copper atom has only 1electron in it’s valence ring. Thismakes it a good conductor. Ittakes 2n2 electrons or in this case32 electrons to fill the valenceshell.
A Silicon atom has 4 electrons inits valence ring. This makes it asemiconductor. It takes 2n2
electrons or in this case or 18electrons to fill the valence shell.
Crystal Energy Band
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© 2012 Pearson Education Inc.
Introduction to Electronics
Copyright @2013 by Dept. of Electrical Engineering, Electronics I- Lecture 1(b)/1st Semester 013/014College of Engineering, Maysan University
Crystal System
• Crystal: is a periodic structure with unit cellsthat are repeated regularly. We classify crystalexternal form in 7 systems based on the shape ofthe crystal.
• Unit cells: Smallest repetitive volume thatcontains the complete lattice pattern of a crystal.
7 crystal systems
14 crystal lattice
a, b and c are the lattice constants
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© 2012 Pearson Education Inc.
Introduction to Electronics
Copyright @2013 by Dept. of Electrical Engineering, Electronics I- Lecture 1(b)/1st Semester 013/014College of Engineering, Maysan University
Crystal System
(c) 2003 Brooks/Cole Publishing / Thomson Learning™
The fourteen(14) types ofBravais latticesgrouped inseven (7)systems.
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© 2012 Pearson Education Inc.
Introduction to Electronics
Copyright @2013 by Dept. of Electrical Engineering, Electronics I- Lecture 1(b)/1st Semester 013/014College of Engineering, Maysan University
Crystal System
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© 2012 Pearson Education Inc.
Introduction to Electronics
Copyright @2013 by Dept. of Electrical Engineering, Electronics I- Lecture 1(b)/1st Semester 013/014College of Engineering, Maysan University
Primitive Face-Centered
Body-Centered End-Centered
A unit cell is the smallest component of the crystal that reproduces thewhole crystal when stacked together.• Primitive (P) unit cells contain only a single lattice point.• Internal (I) unit cell contains an atom in the body center.• Face (F) unit cell contains atoms in the all faces of the planes composing the cell.• Centered (C) unit cell contains atoms centered on the sides of the unit cell.
Combining 7 Crystal Classes (cubic, tetragonal, orthorhombic, hexagonal, monoclinic, triclinic,trigonal) with 4 unit cell types (P, I, F, C) symmetry allows for only 14 types of 3-D lattice.
Unit Cell Types
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