The working principle of an LED (Light Emitting Diode) is based on the phenomenon of electroluminescence, where light is emitted when an electric current flows through a material. LEDs are semiconductors that produce light when electricity passes through them, making them energy-efficient and long-lasting compared to traditional light bulbs.
An LED consists of two layers of semiconductor materials: the p-type and n-type semiconductors. The p-type material has an excess of holes (positive charge carriers), while the n-type material has an excess of electrons (negative charge carriers). When an electric current is applied to the LED, electrons from the n-type material move to the p-type material, where they recombine with holes. This recombination releases energy in the form of light.
The color of the light emitted by an LED depends on the energy band gap of the semiconductor material. Different materials, such as gallium nitride (GaN) or aluminum gallium arsenide (AlGaAs), are used to produce different colors of light. For example, a wider band gap emits blue or ultraviolet light, while a smaller band gap emits red or infrared light.
LEDs are highly efficient because they directly convert electrical energy into light, unlike incandescent bulbs that produce heat as a byproduct. The low heat emission makes LEDs more energy-efficient and durable. LEDs also have a longer lifespan, with some lasting up to 50,000 hours or more, compared to the 1,000-hour lifespan of traditional incandescent bulbs.
Due to these advantages, LEDs are widely used in various applications, including displays, indicator lights, automotive lighting, and general lighting. Their ability to emit bright, clear light while consuming less energy makes them a popular choice for both residential and commercial lighting solutions.