How does an LED differ from a regular diode?

An LED emits light when current flows through it, whereas a regular diode does not.

An LED, or light-emitting diode, is a type of diode that emits light when current flows through it. This is due to a process called electroluminescence, in which electrons in the semiconductor material recombine with holes, releasing energy in the form of photons. LEDs are commonly used in lighting, displays, and indicators, and are more energy-efficient than traditional incandescent bulbs.

In contrast, a regular diode is designed to allow current to flow in only one direction. When a voltage is applied in the forward direction, the diode conducts current, but when the voltage is reversed, the diode blocks current flow. This property makes diodes useful in rectification circuits, which convert AC voltage to DC voltage.

While both LEDs and regular diodes are made of semiconductor materials such as silicon or gallium arsenide, LEDs are designed with a specific structure that allows for efficient light emission. This structure includes layers of different materials, such as a p-type layer and an n-type layer, that create a junction where electrons and holes can recombine and emit light. Overall, the key difference between an LED and a regular diode is that an LED is designed to emit light, while a regular diode is designed to allow current flow in only one direction.