If you were going to list the most essential technologies of the 21st century, semiconductors would definitely be near the top of the list. Semiconductors are the behind-the-scene materials used in semiconductor devices which are responsible for the information age and made it possible. These devices include actuators and control systems in cars, a wide variety of computers, MP3 players, and cell phones. In this day and age it’s hard to imagine life without these technological tools.
To put it simply, a semiconductor is used to control the flow of energy in an electronic setting. A device that has a semiconductor is composed of materials like silicon or geranium which can easily be manipulated (i.e. through exposure to light, pressure, or heat). The control of these materials influences how power can be reached and used in electronic devices.
The most common semiconductors are a diode and a transistor. A diode is a device which has two electronic terminals and allows the flow of energy in one direction only while blocking the flow of energy in the reverse direction. The direction the energy is flowing in a diode is referred to as forward bias. Diodes are commonly made out of silicon and can be used to prevent voltage spikes, function as a switch, and alter AC current to DC current.
A transistor is a semiconductor in which the energy flowing from a smaller terminal can set off a signal which can control the signal of a larger terminal. Transistors are most commonly used for amplification and as switches of electrical signals. A common transistor is a PNP transistor which utilizes a semiconductor material which has an excessive amount of electrons. This material is then placed between two other semiconductor materials which have a lack of electrons, or an excessive amount of electron holes. These transistors can often be found in circuit boards in various computers.