How do diodes work in an electronic circuit?

Diodes allow current to flow in one direction and block it in the other direction.

Diodes are electronic components that allow current to flow in one direction but block it in the opposite direction. They are made of a semiconductor material, such as silicon, with a p-n junction. The p-type material has an excess of positively charged holes, while the n-type material has an excess of negatively charged electrons. When the two materials are joined, the holes and electrons diffuse across the junction, creating a depletion region with no free charge carriers.

When a voltage is applied to the diode in the forward direction, with the positive terminal connected to the p-type material and the negative terminal connected to the n-type material, the depletion region narrows and the holes and electrons recombine, allowing current to flow. However, when a voltage is applied in the reverse direction, with the positive terminal connected to the n-type material and the negative terminal connected to the p-type material, the depletion region widens and no current can flow.

Diodes have many applications in electronic circuits, such as rectification, voltage regulation, and signal modulation. They can be used to convert AC to DC, to protect sensitive components from reverse voltage, and to limit the amplitude of a signal. Diodes also have non-linear properties that can be exploited for functions such as clipping, switching, and mixing. Understanding the behaviour of diodes is essential for designing and analysing electronic circuits.