ABSTRACT
Valence electrons are weakly bound to the atomic lattice and are free to move about from atom to atom.
Valence electrons are tightly bound to the atomic lattice and are fixed in position.
In semiconductors, thermal vibration of atoms in a crystal causes electrons to break away and become free. The solid then becomes weakly “conducting”: e.g., these two
Intrinsic semiconductor
The addition of certain impurities (doping) to the silicon lattice can increase conductivity. P atom is still
1. Introduction of a phosphorous atom (5 valence electrons)
This results in increased conductivity due to availability of negative mobile charge carriers
and hence is called an n-type semiconductor.
