Schottky diodes are also known as hot carrier diodes. Let's understand why they are called so.

1. Introduction
- Schottky diodes are a type of semiconductor diode that have a low forward voltage drop and fast switching characteristics.
- They are formed by the junction of a metal and a semiconductor material, typically a metal layer on a silicon substrate.

2. Operation
- Unlike regular diodes, which are formed by a p-n junction, Schottky diodes are formed by a metal-semiconductor junction.
- The metal layer acts as the anode and the semiconductor material acts as the cathode.
- When a positive voltage is applied to the anode, electrons from the metal layer move into the conduction band of the semiconductor material, creating a flow of current.
- This mechanism is different from the p-n junction diodes, where the current is generated by the movement of both electrons and holes across the junction.

3. Hot Carrier Effect
- The term "hot carrier" refers to the high-energy charge carriers (electrons or holes) that are generated in the vicinity of the metal-semiconductor junction.
- In Schottky diodes, the metal-semiconductor junction has a smaller depletion region compared to p-n junction diodes. This results in a higher electric field near the junction.
- When the diode is forward-biased, these high-energy carriers are generated due to the high electric field.
- The presence of hot carriers influences the diode's characteristics, such as forward voltage drop and switching speed.
- The fast switching characteristics of Schottky diodes are a result of the hot carrier effect.

4. Advantages and Applications
- Schottky diodes have a lower forward voltage drop (typically 0.2V to 0.5V) compared to p-n junction diodes, which results in lower power losses.
- They have a faster switching speed, making them suitable for high-frequency applications.
- Schottky diodes are commonly used in power supplies, voltage clamping circuits, and rectifiers.
- They are also used in high-speed digital circuits, where their fast switching characteristics are beneficial.

As a result of these characteristics and the presence of hot carriers near the junction, Schottky diodes are also referred to as hot carrier diodes.