Light-Emitting Diode (LED)

electronics · light · semiconductors · energy

Glowing semiconductors. Inside an LED, electrons and tiny holes in a special crystal trade places and release energy as light. The tiny flashes of light combine to make the bright glow you see.

Color comes from materials. Different semiconductor materials release different colored light. A red LED uses different material than a blue LED, kind of like how different metals burn different colors in a campfire.

Super efficient. LEDs waste very little energy as heat, unlike old light bulbs that get really hot. This makes them perfect for phones, flashlights, and saving electricity at home.

White light trick. To make white light, engineers can combine multiple colored LEDs or coat a blue LED with a glowing powder called phosphor. This is how your phone's flashlight and stadium lights actually work.

Everywhere now. LEDs light up your TV screen, car headlights, video billboards, and even Christmas decorations. They last longer and use way less power than older light bulbs.