led

  With the development of science and technology, tungsten lamp has been gradually out of the market, we all know that the light bulb is to use the electric shade to heat tungsten wire to incandescent effect, then many friends are curious,   LED light   almost replaced the tungsten lamp, life is very widely used, how does it emit light? LED is short for  light-emitting diode , a type of semiconductor diode that converts electrical energy into light energy.Led and ordinary diode is composed of a PN junction, also has one-way conductivity.When a forward voltage is applied to the led, the holes in the n-region are injected from the p-region and the electrons in the p-region are injected from the n-region. The electrons in the n-region and the holes in the p-region are compounded with the electrons in the n-region and the holes in the p-region within a few microns around the PN junction, respectively, to produce spontaneous emission fluorescence. The energy states of ele...