About classification of materials

1. CLASSIFICATION OF
MATERIALS
PRESENTED BY,
S.Suvathini,
ECE- 2nd year,
115011013912
All Rights reserved. Not for distribution. Single user license

2. SYNOPSIS
*TYPES OF MATERIAL
*CONDUCTOR
*INSULATOR
*ENERGY BAND IN SOLIDS
*CLASSIFICATION ACCORDING TO ENERGY
BANDS
*SEMICONDUCTOR
*TYPES OF SEMICONDUCTOR
*TYPES OF EXTRINSIC
SEMICONDUCTOR

3. TYPES OF MATERIALS
CONDUCTOR1
INSULATOR2
SEMICONDUCTOR3

4. CONDUCTOR AND INSULATOR
1 Conductor: material
which conduct electron
2 Examples: copper,
aluminium etc.
3 Insulator: which does
not conduct electron
4 Examples: wood, glass,
plastics and rubber etc

5. ENERGY BAND IN SOLID
1
VALENCE
BAND
2
Conduction
band
3
Forbidden
energy

6. ENERGY BAND
Valence band:
energy
experienced by
electron in
outermost orbit
1 Conduction
band: energy
experienced by
electron during
movement from
one place to
other
2 Forbidden
energy: energy
given to electron
to move from
valence band to
conduction band
3

7. CLASSIFICATION OF MATERIAL
ACCORDING TO ENERGY BAND
CONDUCTOR: both valence band and
conduction band is filled
INSULATOR: valence band is full and
conduction band is empty
SEMICONDUCTOR: valence band is filled and
conduction band is partially filled

8. SEMICONDUCTOR

9. INTRINSIC SEMICONDUCTOR
*Pure form of semiconductor
*conducting properties of intrinsic semiconductor are low
* In a intrinsic semiconductor, the number of free electron
and holes are equal

10. EXTRINSIC SEMICONDUCTOR
*In order to convert intrinsic semiconductor to
extrinsic semiconductor, we need to add impurities.
*The process of adding impurities is called DOPING.
*Extrinsic semiconductor is classified into two
types :
•P-type semiconductor
•N-type semiconductor

11. TYPES OF EXTRINSIC SEMICONDUCTOR
• If we add
pentavalent
impurities to
intrinsic
semiconductor.
• Example:
Arsenic,
antimony
P-TYPE
• If we add
trivalent
impurities to
intrinsic
semiconductor
• Example:
boron,
indium
N-TYPE

12. THANK YOU