Semiconductor
What is Semiconductor?
A semiconductor is a crystal material, whose electrical conductivity is between that of a conductor and that of an insulator. It has ability to conduct electricity rises as its temperature goes up. That is, it sometimes acts as a conductor and sometimes as an insulator. Its conducting ability can be much increased by chemical treatment. A manufactured chip of silicon, less than half an inch square, may contain millions of microscopic transistors, which can serve control and memory functions when installed in a computer, automobile, cell phone, DVD player, or microwave oven.
Fig.no.1: Semiconductor
Types of Semiconductor
The specific properties of a semiconductor depend on the impurities, added to it.An N-type semiconductor carries current mainly in the form of negatively-charged electrons, in a manner similar to the conduction of current in a wire.
A P-type semiconductor carries current predominantly as electron deficiencies called holes. A hole has a positive electric charge, equal and opposite to the charge on an electron. In a semiconductor material, the flow of holes occurs in a direction opposite to the flow of electrons.