Schottkydiodid

Schottkydiodid, or Schottky diode, is a type of diode based on a metal–semiconductor junction. It is known for a low forward voltage drop and very fast switching, properties that arise from conduction by majority carriers rather than minority carriers in a p–n junction. The device is formed by a metal electrode in intimate contact with an n-type semiconductor, typically silicon or gallium arsenide, creating a Schottky barrier that controls current flow.

Construction and operation: The metal–semiconductor interface forms the active junction. In forward bias, carriers flow over the barrier with minimal stored charge, producing a low forward voltage. In reverse bias, the barrier widens and the current is limited mainly by the depletion region, leading to very fast switching and negligible reverse recovery time compared with conventional p–n diodes. The barrier height, choice of metal, and semiconductor doping determine the forward drop and breakdown characteristics.

Electrical characteristics: Forward voltage drop is typically around 0.15 to 0.45 volts at moderate currents, lower than standard silicon p–n diodes. The diode switches rapidly due to lack of minority-carrier storage, making it suitable for high-frequency applications. Reverse leakage current exists and increases with temperature and reverse voltage. Breakdown voltage varies with materials and construction and is generally lower than that of comparable pn junction diodes, so Schottky diodes are often used where low voltage operation is sufficient.

Applications: Schottky diodes are widely used in power rectification for switch-mode power supplies, high-speed and RF circuits, clamping and protection circuits, and detector or mixer roles in radio frequency systems. Their combination of low forward drop and fast switching makes them advantageous where efficiency and speed are critical, though they are less suitable for high-voltage or high-current applications.

See also: Schottky barrier diode.