General Concept
A semiconductor is a material that has one too many electrons in its outermost shell. They have properties of both conductors and insulator that we can control by changing the amount of energy we apply to the material. Most semiconductors are made with crystals but there are types of intrinsic semiconductors such as Silicon.
Doping
For extrinsic semiconductors we typically dope a material to make it like a semiconductor. The host material is some pure material then we can either do N-type doping or P-type doping. Intrinsic semiconductors are a pure material that behaves like a semiconductor.
N-type Doping
N-type doping is when we add impurities to the material that make it more like a conductor. Thus we add a material with more valence electrons.
P-type Doping
P-type doping is when we add impurities to the material that make it more like a conductor also. But instead of adding a material with more valence electrons we add a material with less valence electrons making more “holes”; a place that’s missing electrons that typically carry charges and increase conductivity.