What Is a Semiconductor?
Semiconductors have replaced bulky and high energy consuming vacuum tubes. Vacuum tubes where once commonplace in televisions and radios. Semiconductors are used in all types of electronic circuits. These circuits utilize semiconductors called diode rectifiers and transistors. They can be found in cell phones, iPods and every electronic gadget on the marketplace today.
Other People Are Reading
-
History
-
The transistor was created or discovered in 1948 at the Bell Telephone Laboratories. The word transistor is derived from transfer resistor: transfer for the way the semiconductors can act like a switch, and resistor for the action of the material to resist certain flows of electrical energy.
Significance
-
A semiconductor consists of materials that act like a conductor and an insulator to the electrical flow of energy. The most common of the materials used in the construction of semiconductors are germanium and silicon. Other impurities can be added to the semiconductor to change its characteristics. The process of adding impurities is called doping.
-
Function
-
The purpose of doping is to add or reduce the amount of free electrons in the semiconductor. The free electrons are what carry the electrical signal through the material. If the free electrons are increased through doping, this will make the material negative, or an N-type. If the electrons are reduced, the semiconductor then becomes positive, or a P-type.
Types
-
Where these two types of opposite material meet in a semiconductor is called a junction. These junctions can be either a PN or NP junction. PN is a positive negative flow and NP is a negative positive flow. Because of the arrangement of the material in the semiconductor, the junction can control the flow of electrical current.
Features
-
You can think of a semiconductor controlling voltage much like the cold and hot water valves for a faucet on a sink. The faucet itself will output the temperature of water as you mix the two streams together. Now, think of putting the mixed water back into the faucet. Causing the water to flow backwards through the separate cold and hot water valves. Let us say, that the cold water is positive and the hot water is negative. The semiconductor junction is able to separate the cold and hot, positive and negative, from the mixed water. The semiconductor now switches back and forth to separate the different charges of positive and negative.
Effects
-
The PN or NP junction is a switch, a very small switch, that can send electrical signals and information extremely quickly. All computer processors are made up of thousands of these types of semiconductor switches. The switches organize electrical signals or information. The computer programs tell which switch, of the thousands in the semiconductor circuits, to turn on and turn off.
-
