What is Semi conductor?

What is Semi conductor? Semi conductor are those material which have resistivity in between of a conductor and insulator .In this purest form semi conductor know as Intrinsic S-conductor.

The Main feature of intrinsic S-conductor are ;

  • R More pure than metal conductors and less than insulator
  • With negative temperature coefficient as R decrease with the rise in temperature .
  • Valence electron is  plus minus 4.This values means that atom has four electrons in the outermost ring-half to the goal of 5 .


By adding impurities the conductivity of material can increase which is the special feature of semi-conductor .This process of  adding impurity element  is called doping .The purpose is to increase the number of free charges that can be move by an external applied voltage .When the Number of free electrons is increased ,the doped semi-conductor is negative or N-type: Reducing number of free electron makes material P-types.Genrmanium  (Ge) and Silicon can be used with either P-type or N-Type doping but silicon S-conductor devices are most common.

What is a Semi conductor

                  Semi –Conductor and Doping Elements.

  Element Symbol Atomic Number No of Valence electrons
Aluminum Al 13 3
Boron B 5 3
Gallium Ga 31 3
Indium In 49 3
Germanium Ge 32 4
Silicon Si 14 4
Antimony Sb 51 5
Arsenic As 33 5
Phosphorous P 15 5
Element Application
Acceptor impurities elements Take electrons to form P-type S-Conductor ,Ga and In used for Ge ,Al and B for Si
Intrinsic S-conductor Used in pure crystal form to be doped with impurities elements.Doped S-conductor are extrinsic 
Arsenic Phosphorous
Donor impurities elements Give electrons to form N-type S-conductor ,As and Sb used for Ge and Phosphorous for Si.

To purchase Electrical products Click Here

You may also read

Leave a Reply

Your email address will not be published. Required fields are marked *