Electronics 1 slide.ppt

8/14/2019 Electronics 1 slide.ppt

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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.



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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 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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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

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Electronics 1 slide.ppt