Semiconductors

A semiconductor is a material whose electrical conductivity lies between that of a good conductor and an insulator. It does not conduct electricity as easily as metals, but its conductivity can be controlled, which makes it extremely useful in electronic devices. Silicon and germanium are common semiconductor materials. In a semiconductor, electrical conduction can occur through moving electrons and through holes. A hole represents the absence of an electron and behaves like a positive charge carrier. One important property of semiconductors is that their conductivity can be changed by adding a very small amount of another material. This process is called doping. Doping can produce two important semiconductor types: N-type: electrons are the majority charge carriers. P-type: holes are the majority charge carriers. Semiconductors are important because they are used to make components such as diodes, LEDs, transistors and integrated circuits.