The LED
The LED (= light-emitting diode) is a diode which is able to emit light. The color of the emitted light is influenced by the material used. When a voltage is applied between the two layers (there is a negatively doped layer (n) and a positively doped layer(p)) in the direction of the flux, the excess electrons migrate towards the p-layer. Recombination then occurs in the junction layer, resulting in flashes of light (photons).