Name: Energy Band Gap
Uploaded: 2019-07-19
Duration: 5 min 21 s
Description: We know that certain materials conduct electricity whereas some don’t. Has it got anything to do with their energy bandgap? Let’s find out in this video.

Question

Distinguish between extrinsic and intrinsic semiconductor.

Accepted Answer

Intrinsic semiconductors vary from extrinsic semiconductors in that they are the purest type of semiconductor materials. Extrinsic semiconductors, on the other hand, are impure semiconductors produced by mixing an impurity with a pure semiconductor. The difference between them is explained below.

Since no external impurity has been added, intrinsic semiconductor is a pure type of semiconductor crystal. Since it is in its purest form, it only contains tetravalent elements. The valence band's number of holes must match the number of electrons in the conduction band. They act as insulators at $0 K$ .

Since an additional impurity has been added, extrinsic semiconductor is an impure semiconductor. Doping is the term for the method of addition. The concentrations of electrons and holes in the conduction band and valence band, respectively, are different from the intrinsic carrier concentration at a given temperature in an extrinsic semiconductor. They are further divided into p-type and n-type semiconductors based on the impurities used for doping.

Distinguish between extrinsic and intrinsic semiconductor.

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