A light-emitting diode (LED) is a semiconductor device that emits light when an electric current passes through it. It is a type of diode, which is a two-terminal electronic component with an anode (positive terminal) and a cathode (negative terminal). LEDs are widely used for various lighting applications due to their energy efficiency, durability, and compact size.
The process by which an LED emits light is called electroluminescence. When a forward voltage is applied across the anode and cathode terminals of the LED, electrons and holes (positive charge carriers) recombine within the semiconductor material, releasing energy in the form of photons (light particles). The color of the light emitted depends on the semiconductor material used in the LED's construction.
Different semiconductor materials produce LEDs with different colors. Common colors include red, green, blue, and yellow, but advancements in technology have enabled the development of LEDs that emit white light, which is commonly used for general illumination.
LEDs have revolutionized lighting technology, becoming the preferred choice for many applications, such as:
General lighting: LED bulbs and fixtures are used in homes, offices, and public spaces for energy-efficient lighting.
Automotive lighting: LED headlights, taillights, and interior lighting have become standard in modern vehicles.
Backlighting: LEDs are used in displays such as TVs, computer monitors, and smartphones to provide backlighting.
Signage and displays: LEDs are commonly used in electronic signs, large displays, and advertising boards.
Indicator lights: LEDs are used in various devices and appliances to indicate status or operation.
Compared to traditional incandescent and fluorescent lighting, LEDs are much more efficient, producing less heat and using significantly less electricity. They also have a longer lifespan, making them an environmentally friendly and cost-effective lighting solution.