Schottkybarriär

A Schottky barrier is a metal-semiconductor junction that exhibits rectifying behavior, meaning it allows current to flow predominantly in one direction. This phenomenon is analogous to the p-n junction in a semiconductor diode. The formation of a Schottky barrier is governed by the relative work functions of the metal and the semiconductor. When a metal with a work function higher than that of the semiconductor is brought into contact with it, electrons transfer from the semiconductor to the metal, creating a depletion region in the semiconductor near the interface. This depletion region contains a built-in electric field that opposes further charge flow and establishes equilibrium.

The key characteristic of a Schottky barrier is its low forward voltage drop compared to a p-n junction diode. This is because the majority carriers (electrons in n-type semiconductors or holes in p-type semiconductors) are the primary charge carriers that cross the barrier in the forward direction, rather than minority carriers as in p-n junctions. This property makes Schottky diodes highly efficient for high-frequency applications and in power switching circuits where minimizing energy loss is crucial.

Schottky barriers are utilized in various electronic devices, including Schottky diodes, which are used as rectifiers, detectors, and switches. They are also integral to the operation of Schottky transistors, a type of bipolar transistor that incorporates Schottky diodes to prevent transistor saturation and improve switching speed. The precise barrier height, and thus the electrical characteristics of the junction, can be controlled by selecting appropriate metal and semiconductor materials.