State any two trivalent and pentavalent impurities each.
These have 3 valence electrons and create p-type semiconductors.
1. Boron (B)
2. Gallium (Ga)
*(Other examples include Aluminum (Al) and Indium (In).)*
These have 5 valence electrons and create n-type semiconductors.
1. Phosphorus (P)
2. Arsenic (As)
*(Another common example is Antimony (Sb).)*