Doping: The electrical conductivity of intrinsic semi-comductor, which has little current conduction capability at ordinary room temperature and so if of little use, can be increased many times by adding very small amount of impurity to it in the process of crystallisation this process is called the doping.
when a small amount of pentavalent impurity, such as Arsenic,Antimony,Bismuth or phosphorous is added to a pure semi-conductor crystal during the crystal growth,the resulting crystal is called the N-type extrinsic semiconductor,where N stands for negative.
When a small amount of trivalent impurity, such as Boron,Gallium,Indium or Aluminium is added to a pure semi-conductor crystal during the crystal growth the resulting crystal is called the P-type extrinsic semiconductor,Where P stands for positive.
Hole: When energy is supplied to a semiconductor, a valence electron is shifted to a higher energy level; the departing electron leaves a vacancy in the valance band. This Vacancy is called a Hole
Majority Charge Carrier: In the intrinsic state, the number of free electron or Germanium is due only to those few electrons in the valence band that have acquired sufficient energy from heat or light sources to break the covalent bond the vacancies left behind in the covalent bonding structure represent very limited supply of holes. In the N-type material, thr number of holes has not changed significantly from this intrinsic level and the number of electrons for out weights the number of thermally generated holes. Hence in a N-type material electrons are majority carriers and responsible for the P-type material i.e P-type material have holes as majority carries and free electrons as minority carriers.
Impurity: Impurity is also called as a doping material. so the doping material may be either pentavalent or trivalent. According to impurity introduced may be of two types viz.
(i) Donor type or N-type.
(ii) Accepter or P-type.
Pentavalent (or donor) impurity such as Arsenic, Antimony,Bismuth or Phosphrous etc. The amount of impurity which is required to be added to have appreciable effect on the conductivity is very small.
when a small amount of pentavalent impurity, such as Arsenic,Antimony,Bismuth or phosphorous is added to a pure semi-conductor crystal during the crystal growth,the resulting crystal is called the N-type extrinsic semiconductor,where N stands for negative.
When a small amount of trivalent impurity, such as Boron,Gallium,Indium or Aluminium is added to a pure semi-conductor crystal during the crystal growth the resulting crystal is called the P-type extrinsic semiconductor,Where P stands for positive.
Hole: When energy is supplied to a semiconductor, a valence electron is shifted to a higher energy level; the departing electron leaves a vacancy in the valance band. This Vacancy is called a Hole
Majority Charge Carrier: In the intrinsic state, the number of free electron or Germanium is due only to those few electrons in the valence band that have acquired sufficient energy from heat or light sources to break the covalent bond the vacancies left behind in the covalent bonding structure represent very limited supply of holes. In the N-type material, thr number of holes has not changed significantly from this intrinsic level and the number of electrons for out weights the number of thermally generated holes. Hence in a N-type material electrons are majority carriers and responsible for the P-type material i.e P-type material have holes as majority carries and free electrons as minority carriers.
Impurity: Impurity is also called as a doping material. so the doping material may be either pentavalent or trivalent. According to impurity introduced may be of two types viz.
(i) Donor type or N-type.
(ii) Accepter or P-type.
Pentavalent (or donor) impurity such as Arsenic, Antimony,Bismuth or Phosphrous etc. The amount of impurity which is required to be added to have appreciable effect on the conductivity is very small.
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