Light-emitting diode into a lower energy level and releases energy in the form of a photon. The wavelength of the light emitted, and thus its color, depends on the band gap energy of the materials forming the "p-n junction". In silicon or germanium diodes, the electrons and holes usually recombine by a "non-radiative transition", which produces no optical emission, because these are indirect band gap materials. The materials used for the LED have a direct band gap with energies corresponding to near-infrared, visible, or near-ultraviolet light. LED development began with infrared and red devices made with gallium arsenide. Advances in materials science
LED lamp organizations recommend that people should not use bluish white lamps at night. The American Medical Association argues against using bluish white LEDs for municipal street lighting. Research suggests that the shift to LED street lighting attracts 48% more flying insects than HPS lamps, which could cause direct ecological impacts as well as indirect impacts such as attracting more gypsy moths to port areas. LED lamp A LED lamp or LED light bulb is an electric light for use in light fixtures that produces light using light-emitting diode (LED). LED lamps have a lifespan many times longer than equivalent incandescent lamps,