What are semiconductors? Give examples.
Materials having resistivity or conductivity in between conductors and insulators, are called semiconductors.
These are the materials with the forbidden energy gap between valence and conduction band <3eV. It is less than that of insulators (>3eV) and more than that of conductors.
e.g.
Elemental semiconductor: Germanium, silicon, selenium, etc.
Compound semiconductors: Gallium, arsenide, Indium, phosphide, cadmium, sulphide etc.