The Schottky diode (named after German physicist Walter H. Schottky; also known as hot carrier diode) is a semiconductordiode with a low forward voltage drop and a very fast switching action. Typical applications include discharge-protection for solar cells connected to lead-acid batteries and in switched-mode power supply; in both cases the low forward voltage leads to increased efficiency. While standard silicon diodes have a forward voltage drop of about 0.6 volts and germanium diodes 0.2 volts, Schottky diodes voltage drop at forward biases of around 1 mA is in the range 0.15 V to 0.46 V, which makes them useful in voltage clamping applications and prevention of transistor saturation. This is due to the higher current density in the Schottky diode.
See more at Wikipedia.org...