Extrinsic Semiconductor

IMPORTANT

Extrinsic Semiconductor: Overview

This Topic covers sub-topics such as p-Type Semiconductor, N-type Semiconductor, Extrinsic Semiconductor, Doping, Dopant, Process of Doping, Doping and Dopant and, Some Important Facts about p-Type Semiconductor

Important Questions on Extrinsic Semiconductor

MEDIUM
IMPORTANT

An intrinsic semiconductor has 5×1028 atoms and carrier concentration 1.5×1016 m-3. If it is doped by a pentavalent impurity in the ratio 1:106, then calculate the number density of holes as charge carriers.

MEDIUM
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In a pure semiconductor crystal of Si, if antimony is added then what type of extrinsic semiconductor is obtained. Draw the energy band diagram of this extrinsic semiconductor so formed.

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Which of the following energy band diagram shows the N-type semiconductor

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A P-type semiconductor has more holes than electrons.

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The hole density (ηh) and electron density (ne) in p-type semiconductors are related as

MEDIUM
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Range of energy required by electron of valance band to move into hole is 0.01-0.05 eV. The accepter energy level lies

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Which of the following energy band diagram shows the N-type semiconductor

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A common p-type doped for silicon is boron or _____.

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There are two types of dopants,n-type dopants and p-type dopants.

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The energy gap between conduction band and valence band in n-type semiconductor is

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In the energy band diagram given in figure open circles and filled circles denote hole and electrons respectively. The material is

Question Image

MEDIUM
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A semiconductor has equal electron and holes concentration of 6×108 m-3. On doping with certain impurity, electron concentration becomes 9×1012 m-3. Then the semiconductor is

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Electric current in extrinsic semiconductor in respect of mobility is expressed as

HARD
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Electric current in extrinsic semiconductor is

MEDIUM
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The electric current in an extrinsic semiconductor is the sum of currents due to electrons and holes

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In an n-type semiconductor, majority charge carriers are electrons.

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If ne and nh represent the number density of electrons and holes in extrinsic semiconductor respectively then for p-type semiconductors.

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When Pentavalent atoms are added to pure semiconductor then which type of extrinsic semiconductor is found

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Silicon doped with boron or gallium is a perfect example of p-type semiconductor.

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In a p-type semiconductor, there is an _____ in the density of unfilled states.