Physics help from experts.
Light emitting diodes (LED's) are electronic devices that allow electricity to travel in only one direction. They emit light when electric current passes through them.
Light emitting diodes are PN type diodes that produce monochromatic light with low power consumption and little heat dissipation. Because LED's produce little heat and are built of durable material, they last longer than other light sources. LED's can be manufactured to produce a wide range of wavelength from infrared through visible to ultraviolet.