Differentiate between extrinsic and intrinsic semiconductor, Chemistry

Assignment Help:

Differentiate between extrinsic and intrinsic semiconductor. Obtain an expression for the carrier concentration for an intrinsic semi-conductor. Also demonstrate that Fermi level in an intrinsic semiconductor lies approximately half way between the top of valence band and the bottom of conduction band.

In intrinsic semiconductors, conduction is because of intrinsic processes characteristics of crystal, without influence of impurities. A pure crystal of silicon or germanium is an intrinsic semiconductor. Electrons which are excited from the top of the valence band to the bottom of the conduction band by thermal energy are responsible for conduction. Number of electrons excited across the gap can be calculated from the Fermi-Dirac probability distribution. In extrinsic semiconductors, conduction is because of the presence of extraneous impurities.  Process of deliberate addition of controlled quantities of impurities to a pure semiconductor is known as doping. Addition of impurities markedly increases the conductivity of a semiconductor. Conductivity  of  an  intrinsic semiconductor  depends  on  concentration  of  charge  carriers,  ne and  nh.  Mobility  of conduction electrons  and  holes  µe and  µh can  be  defined  as  drift  velocity  acquired  by them  under  unit  field  gradient.  The conductivity σ of a semiconductor can be written

 

220_semiconductor.png

1780_semiconductor.png


Related Discussions:- Differentiate between extrinsic and intrinsic semiconductor

Filtration, why is filtration in soil and water a slow process and explain ...

why is filtration in soil and water a slow process and explain the colour change in the filtrate

EQUIVALENT WEIGHT, WHAT IS THE EQUIVALENT WEIGHT OF Mg(HCO3)2

WHAT IS THE EQUIVALENT WEIGHT OF Mg(HCO3)2

Bridging group in nomenclature compounds, Q. Bridging group in nomenclature...

Q. Bridging group in nomenclature compounds? A bridging group is indicated by putting the Greek letter 'p' immediately before its name and separated by hyphens from other ligan

atomic weight, what is the atomic weight of oxyge

what is the atomic weight of oxygen

Esters, What are the esters used in paint''s and their names

What are the esters used in paint''s and their names

Comparison of alkyl cyanides and alkyl isocyanides, Test Ethyl c...

Test Ethyl cyanide Ethyl isocyanide Smell Strong but pleasant Extremely unpleasant Dipole moment

Maximum number of unpaired electron, Which of the following has maximum num...

Which of the following has maximum number of unpaired electron (atomic number of Fe 26): (1) Fe          (2) Fe (II)       (3) Fe (III)               (4) Fe (IV) An

Structure of proteins - biomolecules, Structure of proteins The struct...

Structure of proteins The structure of proteins is extremely complex. The basic structure of a protein considers to the number and sequence of the amino acids in its polypeptid

Applications of hyperconjugation, Applications of hyperconjugation (A) ...

Applications of hyperconjugation (A) Carbon-carbon double bond size in alkenes: As we know previously that the more is the number of resonating structures, the very much will

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd