2 In elemental semiconductors (Si or Ge), the n-type or p-type
semiconductors are obtained by introducing ‘dopants’ as defects In
compound semiconductors, the change in relative stoichiometric ratio
can also change the type of semiconductor For example, in ideal GaAs
the ratio of Ga:As is 1:1 but in Ga-rich or As-rich GaAs it could
respectively be Ga1