Semiconductor materials
A semiconductor is a conductivity material that has a resistivity between conductors and Insulators. Which means semiconductors are conducting partially.
The Resistivity of semiconductors between the
10-2
Ωm and 104 Ωm.
Some example elements of semiconductors are silicon, germanium, Indium, silicon carbide, Tellurium, Gallium arsenide, Cadmium selenide and so and so.
 |
| silicon |
Silicon is widely used in the manufacturing of semiconducting electronic devices.
What are the types of semiconductors?
There are two types of semiconductors, intrinsic semiconductors and extrinsic semiconductors. In this case, a question arises why? we are dividing into two types of semiconductors because an intrinsic semiconductor is pure and contains no impurity but an extrinsic semiconductor is one in which an impurity with a valency higher or lower than the valency of the pure semiconductor.
What is doping?
Doping is the process of the addition of a very small amount of impurity into an intrinsic semiconductor is called doping. The impurity to be added is of the order of 100 parts per million.
Here doubt occurs on how to add impurity or how to doping semiconductors. Some other methods are used to doping a semiconductor material. The impurity atoms are added to the semiconductor in its molten state, The pure semiconductor is bombarded by ions of impurity atoms.
N-type semiconductor
A small amount of pentavalent impurity such as arsenic is added to a pure germanium semiconductor crystal, that crystal is known as an N-type semiconductor.
 |
| Germanium |
 |
| Arsenic |
P-type semiconductor
A small amount of trivalent impurity is added to a pure semiconductor crystal, that semiconductor crystal is called a P-type semiconductor. For instance, germanium is doped with boron.
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| Germanium |
 |
| Boron |
Semiconductors are used to manufacture many electronic devices like transistors, diodes, resistors, chips etc.
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technology