solar powered traffic sign

But when the two semiconductor connected to form a "PN junction" between them. When the current through the wire on the chip, solar powered traffic sign the electronics will be pushed P area, electron hole recombination, and will be issued in the form of photon energy in the P area, this is the principle of single led solar waring light. The wavelength of light determines the color of the light is determined by the decision of the material to form a PN junction.