SCHOTTKY

Schottky diodes have many useful applications from rectification, signal conditioning and switching, through to TTL and CMOS logic gates due mainly to their low power and fast switching speeds. 

the Schottky Diode also known as a Schottky barrier diode is a solid-state semiconductor diode in which a metal electrode and an n-type semiconductor form the diodes ms-junction giving it two major advantages over traditional pn-junction diodes, a faster switching speed, and a low forward bias voltage.

The metal–to-semiconductor or ms-junction provides a much lower knee voltage of typically 0.3 to 0.4 volts compared against a value of 0.6 to 0.9 volts seen in a standard silicon base pn-junction diode for the same value of forward current.

Variations in the metal and semiconductor materials used for their construction means that silicon carbide (SiC) Schottky diodes are able to turn [ON" with with a forward voltage drop as little as 0.2 volts with the Schottky diode replacing the less used germanium diode in many applications requiring a low knee voltage.