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INTRODUCTORY ELECTRONICS
BY
TORKUDZOR MOSES.
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Atomic Structure Electronic Materials P-N Junction Diodes Bipolar Junction Transistors (BJTs) Small Signal Amplifiers
OUTLINE
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ELECTRONICS
Is the study of the behaviour of electrons
in vacuum(i.e. absence of air, fluids(i.e.gases and liquids) and in crystals.
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THE STRUCTURE OF AN ATOM
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ENERGY BAND STRUCTURE
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ENERGY-BAND DIAGRAM
Valence
Band
ConductionBand
EnergyGap
Insulator
Valence
Band
ConductionBand
Conductor
ValenceBand
ConductionBand
Energy Gap
Semiconductor
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ENERGY-BAND DIAGRAM
Valence Band
Conduction Band
Energy Gap
Electronenergy
Generation of electron-hole pairs
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SEMICONDUCTOR Semiconductors are a group of solids whose electrical
properties are intermediate between conductors andinsulators .
For example, the resistivity of a conductor is of the orderof 10 -8 m, that of an insulator is 10 4 m and that of asemiconductor is 10 -1 m
BASIC SEMICONDUCTORCONCEPTS
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Semiconductors are group IV elements i.e.each has four valence electrons.
They are therefore called Tetravalent Atoms
The valence electrons are shared with fourneighboring atoms in a tetrahedral
arrangement forming covalent bonds,which maintain the crystalline solidstructure.
BASIC SEMICONDUCTORCONCEPTS
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BASIC SEMICONDUCTOR CONCEPTS
Silicon crystalline structure with covalent bonds
Si
Si
Si Si
SiSi
Si SiSi
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BASIC SEMICONDUCTOR CONCEPTS(Semiconductor Atoms)
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BASIC SEMICONDUCTORCONCEPTS
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BASIC SEMICONDUCTOR
CONCEPTSINTRINSIC SEMICONDUCTOR
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DOPING
The main reason semiconductor materialsare so useful is that their behaviour can
easily be manipulated by the addition ofimpurities, through a process calleddoping .
Extrinsic SemiconductorN- type SemiconductorP-type Semiconductor
BASIC SEMICONDUCTOR
CONCEPTS
http://en.wikipedia.org/wiki/Doping_(Semiconductors)http://en.wikipedia.org/wiki/Doping_(Semiconductors) -
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BASIC SEMICONDUCTORCONCEPTS
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BASIC SEMICONDUCTORCONCEPTS
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P-N JUNCTION
P-n junction
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P-N JUNCTION
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P-N JUNCTION FORWARD BIAS
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P-N JUNCTIONREVERSE BIAS
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I-V CHARACTERISTICS
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Zener effect Zener breakdown occurs when the electric
field in the depletion layer increases to the point where it can break covalent bonds
and generate electron hole pairs. Avalanche effect This occurs when the minority carriers that
cross the depletion region under theinfluence of the electric field, gain sufficientkinetic energy to be able to break covalentbonds in atoms with which they collide
BREAKDOWN REGION
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Semiconductor devices play an indispensable role inelectronics
Semiconductor devices are electronic components that exploit the electronic properties of
semiconductor materials, principally silicon ,germanium , and gallium arsenide etc.
SEMICONDUCTOR DEVICES
http://en.wikipedia.org/wiki/Electronic_componenthttp://en.wikipedia.org/wiki/Electronicshttp://en.wikipedia.org/wiki/Semiconductorhttp://en.wikipedia.org/wiki/Siliconhttp://en.wikipedia.org/wiki/Germaniumhttp://en.wikipedia.org/wiki/Gallium_arsenidehttp://en.wikipedia.org/wiki/Gallium_arsenidehttp://en.wikipedia.org/wiki/Germaniumhttp://en.wikipedia.org/wiki/Siliconhttp://en.wikipedia.org/wiki/Semiconductorhttp://en.wikipedia.org/wiki/Electronicshttp://en.wikipedia.org/wiki/Electronic_component -
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In the early days of radio andtelevision, transmitting and receiving
equipment relied on vacuum tubes, butthese have been completely replaced in
the last three decades bysemiconductor devices, which includetransistors, diodes, relays integrated
circuits and other electronic
components
SEMICONDUCTOR
DEVICES
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SEMICONDUCTOR
DEVICES
Diodes Transistors Integrated circuits
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SUMMARY*Electronics
*Energy Band Concept*Basic Semiconductor Concepts
*PN junction
*I-V characteristics*Semiconductors Devices
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THANK YOU
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BASIC SEMICONDUCTOR CONCEPTS