semiconductors essays

semiconductors essays The Best type of conductors have only one valence electron. Examples of these types of conductors are silver, copper, and gold. The best type of insulators have 8 electrons. A semiconductor is an element with electrical properties between both those of a conductor and those of an insulator. Semiconductors have four valence electrons. Germanium was the only element used to make semiconductor years ago. However, excessive reverse current was unable to be figured out by engineers which eventually lead them to becoming obsolete in electronics today. The main semiconductor used today is silicon, which is the second most abundant element on the earth besides oxygen. Without silicon, the world we live in today would be completely different. For silicon is used in every computer system, telecommunication system, etc. in the world. The ability to increase the conductivity of a semiconductor is called doping. Doping a semiconductor is called an extrinsic semiconductor. There are two types of extrinsic semiconductors. The n-type semiconductor and the p-type semiconductor. When the n-type is connected to the negative source and the p-type is connected to the positive source this creates forward bias. When there is forward bias the current conducts easily. For example on the diode curve in experiment number 1. If the source voltage is greater than .7V, a silicon diode allows a continuous flow of current in a forward direction. (See Figure 1.) If you would switch the DC source around you would get reverse bias. When there is reverse bias there is a surface leakage. The current barely conducts and is approximately zero in a silicon diode. ...