LED stands for light-emitting diode. They are becoming very popular because of their many advantages, including high energy efficiency, long operating, durability and excellent color quality. Here's how they work.
An LED is a semiconductor diode, which is a small chip of silicon treated with chemical elements that create a positive-negative (p-n) interaction. The positive side contains electron holes while the negative side contains free electrons. When connected to a power source, the holes and electrons are forced into the middle p-n junction. When an electron meets a hole, it releases energy in the form of a light photon. Unlike traditional light sources, LEDs emit colors directly without a chemical chain reaction with mercury or filaments. The color of an LED depends on the chemical element in the diode.
LED fixtures consist of multiple rows of diodes. Each diode is about 1/4 inch in diameter and can be grouped together tightly for high-intensity uses, such as parking lot lighting. Conventional lamps shine light in all directions; a light fixture is needed to point the light where it is needed. LED lamps are directional by nature, pointing light in one direction with little waste.
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