Mention any two ways of increasing the conductivity of an intrinsic semiconductor.

Explanation

i. In the first method, the conductivity can be increased in Silicon or Germanium, by increasing the hole population, by doping or adding a trivalent impurity atom such as Boron (B), Aluminium (Al), Gallium (Ga) or Indium (In).
ii. In the second method, the conductivity can be increased in Silicon or Germaniun, by increasing the electron population by doping with a pentavalent impurity atom such as phosphorous (P), Arsenic (As) or Antimony (Sb).