Topic summary
Semiconductors
Extracted from the Wikipedia article Semiconductor.
Variable electrical conductivity
Semiconductors in their natural state are poor conductors because a current requires flow of electrons, and semiconductors have their valence bands filled, preventing the entire flow of new electrons. Several developed techniques allow semiconducting materials to behave like conducting materials, such as doping or gating. These modifications have two outcomes: n-type and p-type. These refer to the excess or shortage of electrons, respectively. A balanced number of electrons would cause a current to flow throughout the material.