This is the Power Point Slides and Presentation on Semi Conductors It is one of the topic of Applied Physics It is an Effective Presentation

1. Semi- conductor
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Solid

2.  The type of matter in which molecules are closely packed
together. The molecules are closely packed together that they
can not easily move.
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Molecules Of The Solids

3.  According to the electrical properties of the solids they are
divided into three types:
1.Conductors
 The types of solids which allows electricity to pass through them.
2.Insulators
 The types of solids which does not allow electricity to pass through
them.
3.Semi-conductors
 These are solids which are neither a good conductor nor a good
insulator.
 It have properties intermediate between conductors and
insulators.
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4. 4
Insulator-
Any material that does not
allow current to pass through it
Conductor-
Any material that allow
current to pass through it

5. 5
Semi-Conductors
The solids having property intermediate between conductor and insulators
They usually depends upon the temperature
e.g.
if temp rises conductivity of material increases and if temp decreases then
conductivity decreases
Antimony GermaniumSilico
n

6.  There are two types of semi-
conductors:
1. Intrinsic Semi-conductors
 semi conductors which are in pure
form
2. Extrinsic Semi-conductors
 semi conductors which are in
impure form
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7. 7
Doping
The process of adding the small impurity atom in a pure semiconductor is
called doping
Doping of Phosphorus in Pure Silicon

8. 8
Types of Extrinsic Semi-Conductors
There are two types of extrinsic semi cnductors
i. N- type Semiconductors
ii. P- type Semiconductors

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N-Type Semiconductor
The semiconductors which are formed by adding a pentavalent
impurity to a pure semiconductor is called N-type semiconductors
An atom belong to fifth group is a pentavalent.
They are called pentavalent because they have five (5) valence
electrons in outer most shell.
Pentavalent
Carbon Phosphorus

10. P- Type Semiconductor
The Semiconductors which are formed by adding trivalent impurities to a
pure semiconductor are called P- type semiconductor
Trivalent
An atom belongs to third group is a trivalent atom.
These are called trivalent because they have three valence
electron in the outer most shell.
Aluminum Boron

11. p-n Junction
A p-n junction is a boundary between two types of semiconductors.
Donor:
The pentavalent impurity donates a free electron is called donor.
Acceptor:
The trivalent impurity accept a free electron is called acceptor.
Depletion Region:
It is an insulating region formed in p-n junction

12. P-type N-type
Holes Electrons
Depletion Region

13. THANK
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