LEDs differ from traditional light sources in the way they produce light. In an incandescent lamp, a tungsten filament is heated by electric current until it glows or emits light.

In a fluorescent lamp, an electric arc excites mercury atoms, which emit ultraviolet ( UV ) radiation. After striking the phosphor coating on the inside of glass tubes, most of the UV radiation is converted and emitted as visible light.

An LED tube, in contrast, is a tube light with semiconductor diode as light source. LED consists of a chip of semiconducting material treated to create a structure called a p-n ( positive-negative ) junction. When connected to a power source, current flows from the p-side or anode to the n-side, or cathode, but not in the reverse direction. Charge-carriers ( electrons and electron holes ) flow into the junction from electrodes. When an electron meets a hole, it falls into a lower energy level, and releases energy in the form of a photon ( light ).

Need return to FAQs category? Please click here LED FAQs or http://www.eosled.com/faqs/