P type Material and N type Material

P type Materials

The P type material is obtained when a semiconductor is doped with a trivalent impurity such as Aluminium or Boron. P type material is a material which has holes as its majority carriers.  Electrons are the minority Charge Carriers in P type materials.  When a trivalent impurity is added to the crystal lattice of a semiconductor, there is a vacancy for every impurity atom added.  This vacancy is called a hole.

N type Materials

N type materials are made when a semiconductor is doped with a pentavalent impurity.  A pentavalent impurity is one whose atom has five electrons in its outermost orbit (valence electrons).   Examples of pentavalent impurities are Phosphorous, Antimony, Bismuth.  In an N type Material, electrons are the majority charge carriers while holes are the minority charge carriers.

When a semiconductor is doped with a pentavalent impurity for every impurity atom added, there is a free electron.  These electrons are responsible for conduction.