Schottky Diode vs. P-N Diode: Key Differences Explained

This article compares Schottky diodes and p-n diodes, highlighting the fundamental differences between them. We’ll explore their symbols, structures, circuits, and characteristic curves.

P-N Diode

A p-n junction is the metallurgical boundary formed between the n-type and p-type regions within a semiconductor crystal. It consists of these two semiconductor regions with opposite doping types. These junctions exhibit significant rectifying behavior, leading to the creation of p-n diodes.

Figure 1: P-N Diode Symbol

Figure 1 illustrates the standard symbol for a p-n diode.

Figure 2: P-N Diode Structure

Figure 2 shows the structure of a typical p-n junction diode. As depicted, a p-n diode comprises a p-n junction with one connection to the p-side (anode) and another to the n-side (cathode).

Figure 3: P-N Diode Characteristic

Figure 3 presents the characteristic curves for silicon and germanium diodes at 25°C. P-n diodes are commonly used as rectifiers in power supplies to convert AC to DC.

Silicon is generally preferred over germanium due to its superior properties:

• Much lower reverse current.
• Higher breakdown voltage.
• Ability to operate at higher temperatures.

Schottky Diode

Figure 4: Schottky Diode Symbol

Figure 4 illustrates the symbol for a Schottky diode.

Figure 5: Schottky Diode Structure and Circuit

In a Schottky diode, a metal-semiconductor junction is formed at one end, and another metal-semiconductor contact is made at the other. As shown in Figure 5, Schottky diodes use metals like tungsten, aluminum, chromium, platinum, or gold, and typically employ N-type silicon as the semiconductor material.

Figure 6: Schottky Diode Characteristic

Figure 6 shows the characteristic curve of a Schottky diode. The V-I curve is steeper compared to a standard p-n diode. Notably, Schottky diodes exhibit a lower forward voltage drop than p-n diodes.

Key Differences: Schottky Diode vs. P-N Diode