Semiconductors Continued…

The material that they are made of is often very sensitive to any impurities. This allows the semiconductor to function as current switches, as well as amplifiers. The other characteristic that semiconductors have is the presence of two carrier types: negatively charged electrons coupled with positively charged holes.

What are semiconductors used for?

In short, nearly everything computerized. To be more specific, semiconductors are an integral part in photonics. Photonics involves light absorbing and emitting devices, such as diodes and lasers.

Transistors are a type of semiconductor. It is a bit more complex than the simplest of semiconductors, the diode. Transistors are also used in micro processor chips, which contain thousands of transistors. They act as switches and help the chips function properly.

How are semiconductors formed?

As mentioned above, one of the common semiconductor materials is silicone. The only problem is, pure silicone is a very good insulator, hardly an ideal property for a semiconductor.

This is changed by introducing impurities into the silicone crystal. There are two major types of impurities, called doping: N type and P type.

N type involves arsenic or phosphorus. This is added to the silicon in very small amounts, in order to break the perfect covalent bond that the silicon's atoms naturally have. The overall result of this is a negative charge, which lends itself to the name “N type”.

P type involves boron or gallium. This gives the silicon a positive charge, and also changes it to a better conductor. The semiconductor is formed when you put an N type and a P type silicon together.
Both types are conductors, but when put together they do not conduct any electricity, due to their unique nature. The process is more complex when you start getting into transistors and other semiconductors, but the basic premise remains the same.

By Tiffany Garden