① What is LED?
LED is English Light Emitting Diode, namely light-emitting diode, is a kind of semiconductor solid state light-emitting device. It uses solid semiconductor chip as light-emitting material. When both ends are applied with forward voltage, carriers in the semiconductor recombine to cause photon emission. Produce light LED can directly send red, yellow, blue, green, green, orange, purple, white light. The first commercial diode was produced in 1960. Its basic structure is an electroluminescent semiconductor material, placed in a lead frame, and then surrounded by epoxy resin seal, play a role in protecting the internal core, so the LED seismic performance.
② LED is the fourth generation of light (green lighting)?
According to the light source mechanism of light classification: The first generation of light source: resistance glow such as incandescent lamp; The second generation of light source: arc and gas glow such as sodium lamp; The third generation of light source: phosphor light such as fluorescent light; Fourth-generation light source: solid-state chips such as LED light.