1.
Explain the effect doping towards an intrinsic silicon. Give one example of donor element and
one example of acceptor element. [15 marks]
Solution
Silicon is an intrinsic semiconductor. The doping is done to introduce impurities into an intrinsic
semiconductor for modulating its electrical properties. A semiconductor doped to a very high
level can act as a conductor and is generally referred to as degenerate semiconductor
There can be two types of impurities ie., donor type and acceptor type.
Donor type are n-type semi conductors which will increase the number of unpaired electrons. An
example of this is Phosphorus or Arsenic, Antimony, Bismuth
Acceptor type are p-type which will increase the number of holes or hole concentration.
Examples are Aluminum, Gallium, Boron, Indium.