Grade 12th passPhysical Chemistry

Describe the tivo main types of semiconductors and contrast their conduction mechanism.??

Harshit Singh

5 Years agoGrade 12th pass

1 Answer

Pawan Prajapati

5 Years ago

Answer ::.

Main types of semiconductors are of two types :

(i) Intrinsic semiconductor : These are insulators at room temperature and become semiconductors when temperature is raised

(ii) Extrinsic semiconductor :

p-type semiconductor

n-type semiconductor

These are formed by dopping impurity of lower or higher group.

These are subdivided into two types :

• p-type semiconductor : When a silicon crystal is doped with atoms of group-13 elements like B, Al, Ga etc., the atom forms only 3 covalent bonds with the Si atom and 4th missing electron creates a hole which conducts electricity.

• n-type semiconductor : When a silicon crystal is doped with atoms of group-15 elements like P, As etc., then only four of the five valence electrons of each impurity atom, participate in 4 covalent bond formation and 5th e– conducts electricity.

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