Question

Distinguish Between ’intrinsic’ and ‘extrinsic’ semiconductors

Answer 1

INTRINSIC SEMICONDUCTORS:

1. It ispure semi-conducting material and no impurity atoms are added to it.

2.Examples: crystalline forms of pure silicon and germanium.

3. The number of free electrons in the conduction band and the no. of holes in valence band is exactly equal and very small indeed.

4.Its electrical conductivity is low.

5.Its electrical conductivity is a function of temperature alone.

EXTRINSIC SEMICONDUCTORS:

1. It  is prepared by doping a small quantity of impurity atoms to the pure semi-conducting material.

2.Examples: silicon “Si” and germanium “Ge” crystals with impurity atoms  of As, Sb, P etc. or In B, Aℓ etc.

3.The number of free electrons and holes is never equal. There is excess of electrons in n-type semi-conductors and excess of holes in p-type semi-conductors.

4.Its electrical conductivity is high.

5.Its electrical conductivity depends upon the temperature as well as on the quantity of impurity atoms doped the structure.

Answer 2

HEY DEAR ... ✌️

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=) ⏺️] 'Intrinsic semiconductors' =) A pure semiconductor (free from any impurity) is called an 'intrinsic' semiconductor . It's electrical conductivity , which arises by the thermal excitation of electrons from the valence band to the conduction is called the 'intrinsic conductivity' .

⏺️] 'Extrinsic semiconductors' =) The electrical conductivity of intrinsic (pure) semiconductors is too small to be of any practical use . If , however , a small quantity of some pentavalent or trivalent impurity is introduced into a pure semiconductor , the conductivity of semiconductor is significantly increased .

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HOPE , IT HELPS ... ✌️