Schottky diode vs p-n diode-difference between schottky diode and p-n diode

This page compares Schottky diode vs p-n diode and mentions basic difference between Schottky diode and p-n diode. The symbol, structure, circuit and characteristics of both the p-n diode and Schottky diode are compared.

p-n diode

p-n diode symbol

A p-n junction is the metallurgical boundary between the n-region and p-regions of semiconductor crystal. It consists of two semiconductor regions of opposite type. Such junctions will have profound rectifying behavior. They are known as p-n diodes. The figure-1 depicts normal p-n diode symbol.

p-n diode structure

The figure-2 depicts normal p-n junction diode structure. As shown p-n diode consists of p-n junction with one connection to p-side (e.g. anode) and another connection to n-side (e.g. cathode).

p-n diode characteristic

The figure-3 depicts normal p-n diode characteristic. It shows characteristics for silicon and germanium diodes at temperature of 25 degree C. They are used as rectifiers to change AC to DC in power supplies. Silicon is preferred over germanium due to its following properties.
• It has much lower reverse current.
• It has higher breakdown voltage.
• It can work at high temperatures.

Schottky diode

schottky diode symbol

The figure-4 depicts schottky diode symbol.

schottky diode and equivalent circuit

In Schottky diode, a metal semiconductor junction at one end, and another metal semiconductor contact at the other end are formed. This is shown in the figure. Schottky diode uses metals such as tungsten Aluminium, chromium, platinum, gold etc. It uses N-type silicon as semiconductor material. The figure-5 depicts schottky diode structure and circuit.

schottky diode characteristic

The figure-6 depicts schottky diode characteristic. V-I curve of schottky diode is steeper compare to normal p-n diode. As shown schottky diode has lower forward voltage drop compare to p-n diode.
Refer Schottky diode basics>> for more information.

Features Schottky diode P-N diode
Forward current It occurs due to thermionic emission. (majority carrier transport) It occurs due to diffusion currents. (minority carrier transport)
Reverse current It is generated only due to majority carriers which overcome the barrier. (It depends less on temperature.) It is generated due to minority carriers diffusing to the depletion layer and drifting to the other side. (It depends more on temperature.)
Cut-in voltage It is small about 0.3V. It is large about 0.7V.
Speed It has high switching speed due to majority carrier transport. No recombination time needed. It is limited by recombination time of injected minority carriers.
Ideality Factor It is about 1 due to no recombination in depletion layer. It is about 1.2 to 2.0 due to recombination in depletion layer.

Diode Related Links

GUNN Diode➤   Varactor Diode➤   Tunnel Diode➤   PIN Diode➤   Impatt Diode vs Trapatt Diode vs Baritt Diode➤   Tunnel vs normal P-N➤   Schottky Diode➤   Zener Diode➤  

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