Light-emitting diodes (LEDs) are optoelectronic semiconductor devices that generate light via electroluminescence in a p–n junction. Unlike laser diodes, they do not use stimulated emission and have a much wider optical spectrum. A LED is a long-lived light source, but certain mechanisms can cause slow loss of efficiency of the device or sudden. There are many different variants of LEDs. The flat bottom surfaces of the anvil and post embedded inside the epoxy act as anchors, to prevent the conductors from being forcefully pulled out via mechanical strain or vibration. Its applications range from mobile phones to large advertising billboards. The article explains the crucial invention of efficient blue LEDs.
