chapter 1 fundamentals semicond physics v1
TRANSCRIPT
-
8/9/2019 Chapter 1 Fundamentals Semicond Physics v1
1/17
ANALOGUE ELECTRONICS
JEL2103
Muhammad [email protected]
hapter 1:ndamental Semiconductorysics
-
8/9/2019 Chapter 1 Fundamentals Semicond Physics v1
2/17
CONTENT
• Class Introduction
• Resistivity and Conductivity
– Metals
– Semiconductors – Inductors
• Intrinsic and Etrinsic Semiconductors
•
Electrical Conduction – !ri"t and !i#usion
– Carrier li"etime and mo$ility% T&e continuitye'uations
-
8/9/2019 Chapter 1 Fundamentals Semicond Physics v1
3/17
-
8/9/2019 Chapter 1 Fundamentals Semicond Physics v1
4/17
Class Introduction
• Total o" ( c&a)ters
• *rom t&e assessment met&od+ ,ecan conclude t&at t&is course is at&eoretical $ased course – -0. o" t&e total mar/s come "rom t&e
carry mar/s or )ractical
• T,ice a ,ee/ class consist o" t&eoryclass and tutorial
-
8/9/2019 Chapter 1 Fundamentals Semicond Physics v1
5/17
Class Introduction
• Tet$oo/% Electronic Devices'Conventional Current' 9th Edition $y
T&omas L *loyd
• uestions come "rom t&e tet$oo/ – ssinment
– Test
– *inal• Notes ,ill also come "rom t&e tet$oo/
– ,it& etra additional in"o "rom t&e net
-
8/9/2019 Chapter 1 Fundamentals Semicond Physics v1
6/17
Class Introduction
• E4learnin $ased education ,ill $e a))lied
• Reister at% &tt)%55elearninar6n&o$$ycom
• Resources+ tas/s+ and announcement ,ill $e
)osted and u)loaded t&ere• 7lannin to do online assessment too
– Online test
– Online 'ui66es
– Online assinment
• So+ al,ays loin and visit t&e elearnin)ortal
-
8/9/2019 Chapter 1 Fundamentals Semicond Physics v1
7/17
Resistivity and Conductivity
• ll matter is com)osed o" atoms ,&ic& consist o"electrons+ )rotons+ and neutrons 8ece)t normal&ydroen9
• t :rst+ it ,as t&ou&t t&atatom is a tiny indivisi$le
s)&ere $ut later s&o,n t&at
atom ,as not a sinle )article
$ut ,as made u) o" a smalldense nucleus around ,&ic&
electrons or$it at reat distance
"rom nucleus
-
8/9/2019 Chapter 1 Fundamentals Semicond Physics v1
8/17
Resistivity and Conductivity
• Niels ;o&r )ro)osed t&at t&e electrons in anatom circle t&e nucleus in di#erent or$its+similar to t&e ,ay )lanet or$it t&e sun
•
T&is model o"ten re"erred as )lanetary model• It also /no,n as 'uantum model $ut t&is
model are &ard to visuali6e
• *or most )ractical )ur)ose in electronics+ t&e
;o&r model su
-
8/9/2019 Chapter 1 Fundamentals Semicond Physics v1
9/17
Resistivity and Conductivity
• ;o&r model o" an atom is not a com)lete model+ t&us'uantum model need to $e used
• In 'uantum model+ electron does not eist in )recisecircular or$its as )articles
• T&eories o" 'uantum model% – =ave4)article duality% electron are t&ou&t to e&i$it a dual
c&aracteristic 8,ave and )article 8)&oton99 >elocity o"or$itin electron is considered to $e its ,avelent&
– ?ncertain )rinci)le% ,ave is c&aracteri6ed $y )ea/s andvalleys t&us electron t&at act as ,aves cannot $e )reciselyidenti:ed in term o" t&eir )osition resultin a conce)t o"atom ,it& )ro$a$ility clouds 8mat& descri)tions o" ,&ereelectrons in an atom are most li/ely to $e located9
-
8/9/2019 Chapter 1 Fundamentals Semicond Physics v1
10/17
Resistivity and Conductivity
• In 'uantum model+ eac& s&ell orenery level consist o" u) to "oursu$s&ells called orbitals+ ,&ic& are
desinated s p d and ! Or$ital
Maimumelectron
s 2
p 6
d 10
f 14
Notation
E)lanation
1s2
2s2 2 p32 electron in s&ell 1+ or$itals
@ electron in s&ell 2% 2 inor$ital s+ 3 in or$ital p
Eam)le ta$le o" con:uration ta$le o"Nitroen atom
-
8/9/2019 Chapter 1 Fundamentals Semicond Physics v1
11/17
Resistivity and Conductivity
• Eam)le% ?sin t&e atomic num$er"rom t&e )eriodic ta$le+ descri$eSilicon 8Si9 atom usin an electron
con:uration ta$le
• SolutionAA
-
8/9/2019 Chapter 1 Fundamentals Semicond Physics v1
12/17
Resistivity and Conductivity
• Eam)le% ?sin t&e atomic num$er"rom t&e )eriodic ta$le+ descri$eSilicon 8Si9 atom usin an electron
con:uration ta$le
• SolutionAA
-
8/9/2019 Chapter 1 Fundamentals Semicond Physics v1
13/17
Resistivity and Conductivity
• Materials can $e classi:ed into t&ree rou)s% – Conductors
– Semiconductors
– Insulators
•
=&en atoms com$ine to "orm solid and crystalline material+t&ey arrane t&emselves in a symmetrical )attern
• tom in crystal structure are &eld $y
covalent $onds
• T&e $onds are created $y t&e
interaction o" t&e valence electrons
o" t&e atoms
• Eam)le o" crystalline material is Silicon
-
8/9/2019 Chapter 1 Fundamentals Semicond Physics v1
14/17
Resistivity and Conductivity
• toms contri$ute to t&e electrical )ro)ertieso" a material includin its a$ility to conductelectrical current
•
Insulators% Materials t&at does not conductelectrical current under normal conditions
• Conductors% Materials t&at easily conductselectrical current Metals are ood conductors
• Semiconductors% Material t&at is $et,eenconductors and insulators in its a$ility toconduct electrical current
-
8/9/2019 Chapter 1 Fundamentals Semicond Physics v1
15/17
Resistivity and Conductivity
• Semiconductor in its )ure 8intrinsic9 state isneit&er a ood conductor nor a oodinsulator
•=&en electron ac'uires enou& additionalenery+ it can leave t&e valence s&ell and$ecome "ree electron and eist in ,&at is/no,n as t&e conduction "and
• T&e di#erence in enery $et,een valence$and and t&e conduction $and is calledener#y #ap or band gap
-
8/9/2019 Chapter 1 Fundamentals Semicond Physics v1
16/17
-
8/9/2019 Chapter 1 Fundamentals Semicond Physics v1
17/17
Resistivity and Conductivity
• Order o" conductivity% – Su)erconductors B conductors B
semiconductors B insulators