A Schottky diode is a type of metal-semiconductor junction diode that has a low forward voltage drop and a very fast switching speed. It is also known as a Schottky barrier diode, surface barrier diode, majority carrier device, hot-electron diode, or hot carrier diode. The Schottky diode is formed by the junction of a metal with a semiconductor, unlike a conventional PN junction diode which is formed from a piece of P-type material and a piece of N-type material. The Schottky diode has no depletion layer and is classed as a unipolar device. The V-I characteristics of Schottky diodes are very much similar to the PN junction diode, with current being the dependent variable and voltage being the independent variable. The forward voltage drop of the Schottky diode is low, between 0.2 to 0.3 volts. Schottky diodes are often used in high-speed switching applications, such as in computers, RF, and rectifier applications. They are also used in diode rectifiers because of their unique properties. Schottky diodes are more efficient than regular diodes because of their low forward voltage drop, which results in less energy being wasted as heat.