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12 April 2019

Difference between extrinsic and intrinsic semiconductors

Here this post gives the difference between extrinsic and intrinsic semiconductor to better understand this topic.
Difference :

  • Intrinsic semiconductor also called an undoped semiconductor or basically, I type semiconductor are pure semiconductor without any significant species present. The number of charge carriers is therefore determined by the properties of the material itself instead of the number of impurities, while in the extrinsic semiconductor are impure. When a small quantity of impurity is mixed in a pure or intrinsic conductor, a conductivity of semiconductor increases. Such an impure semiconductor is called extrinsic semiconductor 
  • The electrical conductivity of an intrinsic semiconductor is poor while in extrinsic semiconductor conductivity of large
  • While we are using intrinsic semiconductor the number of holes and electrons produced due to the thermal energy are equal  but in extrinsic semiconductor, the number of electrons and holes produced due to the thermal energy are must not be equal
  • The current conduction is due to electrons and hole but in  extrinsic the current conduction is due to either holes or electrons
  •  While we have to use intrinsic semiconductor the Fermi level is at the center of the forbidden energy gap and is unchanged with a change in temperature but in extrinsic, the Fermi level shift upward or downward with a change in temperature
  • In an intrinsic semiconductor, the electrical conductivity is a function of temperature to be alone but in extrinsic semiconductor, the electrical conductivity depends upon the temperature as well as on the number of impurity atoms doped the structure
  • The impurity like arsenic, antimony, phosphorus,  and aluminum indium, etc is added to the pure form of silicon and germanium to form an extrinsic semiconductor. The pure form of silicon and germanium type of crystal is used in an intrinsic semiconductor
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