Schottky diode
Schottky Diode
Schottky Diode
A Shockley diode uses a metal-semiconductor junction instead of a p-n semiconductor-semiconductor junction. This results in a device with a much lower forward bias voltage drop and much faster switching times.
That is a DIODE, which can be of any of these types:P-N junction (shown above)point contactschottky barrier (i.e. metal-semiconductor junction)
junction diodeThere are two other ways of making a simple solid state diode:point contact diode, one piece of semiconductor with a sharp metal needle point touching itmetal-semiconductor diode, a layer of metal over a layer of semiconductor
The schottky diode is based on a metal-semiconductor junction, called a schottky barrier, that results in lower forward voltage and vastly decreased switching time. While an ordinary silicon diode has a forward voltage around 0.7 volts, with a germanium diode around 0.3 volts, the schottky can be as low as 0.15 volts. The switching time can be in the tens of picoseconds range, compared to hundreds of nanoseconds. The downside is limited reverse voltage rating and poor reverse voltage leakage, which increases with temperature, causing potential thermal runaway.
It can be either a junction or point contact diode built with semiconductor material. there are many types depending on intended usage.junction diode is produced as described in its name by forming a junction in the semiconductor by using opposite types of dopant impurities.point contact diode is produced as described in its name by taking a semiconductor base and pressing a sharp metal point on its surface.A few of the types of semiconductor diodes are: small signal, power rectifier, zener, tunnel, gunn, etc.
An ordinary semiconductor diode uses a P-N junction, but when reverse biased it takes a period of time to remove the current carriers from that junction to create the depletion region that blocks reverse conduction. A Shockley diode instead uses a P semiconductor-metal junction, which removes the current carriers much faster from the semiconductor allowing the device to switch much faster. It also has a much lower forward bias voltage than an ordinary diode. In many ways it is similar to the previous point contact diodes (a piece of semiconductor like galena or germanium with a metal "cat's whisker" point contact) in operation, but is more reliable and easier to mass produce.
A very high speed bipolar junction transistor having a metal-semiconductor emitter base junction instead of a semiconductor-semiconductor emitter base junction.
metal-semiconductor junction diodes
The first modern semiconductor diode was made with germanium. These diodes were invented in ww2 for RADAR. But before that semiconductor diodes were made with galena (lead sulfide), copper oxide, and selenium. I have no idea which was "first".
Its schotlky diode. schotlky diode is metal semi conducter junction. It has fast switchng speed. The cutting voltage of schotlky diode is about 0.2 volts.