What is the difference between a diode and a zener diode?

A diode allows current to flow in one direction, while a zener diode can also conduct in reverse.

Diodes are semiconductor devices that allow current to flow in one direction while blocking it in the other. They are commonly used in rectifiers, voltage regulators, and signal detectors. When a diode is forward-biased, it conducts current easily, but when it is reverse-biased, it blocks current flow. This property makes diodes useful in many electronic circuits. For a deeper understanding of how these properties relate to electric fields, see Electric Field Basics.

Zener diodes are a special type of diode that can conduct in reverse when a certain voltage is reached. This voltage is known as the breakdown voltage or the zener voltage. When the voltage across a zener diode exceeds its breakdown voltage, the diode conducts in the reverse direction, allowing current to flow. Zener diodes are commonly used in voltage regulators, surge protectors, and voltage references. They exploit the nature of electric fields, which you can learn more about in the section on Nature of Electric Fields.

The main difference between a diode and a zener diode is that a diode only conducts in one direction, while a zener diode can conduct in both directions when a certain voltage is reached. This property makes zener diodes useful in applications where voltage regulation or protection is required. Zener diodes can also be used as voltage references, as their breakdown voltage is very stable over a wide range of temperatures and currents. The stability of this breakdown voltage can be compared to the kinetic and potential energy behaviours in simple harmonic motion detailed in Kinetic and Potential Energy in SHM.

A-Level Physics Tutor Summary: In summary, a diode only lets current flow one way, useful in electronic circuits. A zener diode, however, can also allow current to flow backwards when a specific voltage is reached, making it ideal for voltage control and protection in devices. The key difference is that zener diodes offer more versatility for managing voltage in electronic applications.