Describe the two main types of semi conductors and contrast their conduction mechanism?

Semi conductors are two types. They are n-types semiconductors and p-type semi
conductors.
n-type semi conductors: Semi conductors obtained by doping of VA-group element into IV-group
element lattice are called n-type semi conductors.
When P or As is added to Si or Ge some of the Si or Ge atoms in the crystal are replaced by
P (or) ‘As’ atoms and four out of five electrons of ‘P or As’ atom will be used for bonding with Si
or Ge atoms while the fifth electron serve to conduct electricity.
p-type semi conductors: Semi conductors obtained by doping of IIIA-group element into IV-group
element lattice are called p-type semi conductors.
When B or Al is added to pure Si or Ge some of the Si or Ge in the crystal is replaced by B
or Al atoms. Three electrons of B or Al atom will be used for bonding with Si or Ge atoms while the
fourth is the electron vacancy (hole) serves to conduct electricity.