Electroluminescence facts for kids

Electroluminescence (EL) is a fascinating way some materials create light. It happens when an electric current passes through them or when they are placed in a strong electric field. This process makes the material glow without getting hot, which is different from how a regular light bulb works.

What is Electroluminescence?

Electroluminescence is a special kind of light emission. It's an optical and electrical event. This means it involves both light and electricity. When certain materials are given electricity, they start to glow. This glow is often soft and even.

How Does Electroluminescence Work?

Inside materials that show electroluminescence, there are tiny particles called electrons. When you apply electricity, these electrons get a burst of energy. They jump to a higher energy level. But electrons don't like to stay at high energy levels for long. So, they quickly fall back down to their normal energy level. When they fall, they release the extra energy they gained. This energy is released as light! It's a bit like a tiny light show happening inside the material.

Where Do We See Electroluminescence?

Electroluminescence is used in many everyday items. You might not even realize it!

• Backlights: Many older digital watches and calculators used EL for their backlights. This made it easy to read the screen in the dark. Some modern liquid crystal displays (LCDs) also use EL backlights.
• Car Dashboards: In the past, some car dashboards used EL panels. This gave the gauges a smooth, even glow at night. It looked very futuristic for its time!
• Nightlights: Some small, flat nightlights use EL technology. They are very thin and use very little power.
• Signs and Displays: You might see EL used in thin, flexible signs or decorative lighting. Because the material is thin, it can be shaped in many ways.

Advantages of Electroluminescence

Electroluminescent lights have several cool benefits:

• Thin and Flexible: EL panels can be made very thin. Some can even be bent! This makes them useful for designs where space is limited.
• Even Light: They produce a very uniform light across their surface. There are no hot spots or dark areas.
• Low Power: Many EL devices use very little electricity. This makes them energy-efficient.
• Cool to the Touch: Unlike traditional light bulbs, EL materials don't produce much heat. They stay cool, which is safer and more efficient.

Images for kids

• 

  Views of a liquid crystal display, both with electroluminescent backlight switched on (top) and switched off (bottom)

• 

  Spectrum of a blue/green electroluminescent light source for a clock radio (similar to the one seen in the above image). Peak wavelength is at 492  nm and the FWHM spectral bandwidth is quite wide at about 85  nm.

• 

  An electroluminescent nightlight in operation (uses 0.08 W at 230 V, and dates from 1960; lit diameter is 59 mm)

• 

  A Casio digital LCD watch with an electroluminescent backlight.

• 

  1966 Dodge Charger instrument panel with electroluminescent lighting. Chrysler first introduced cars with EL panel lighting in its 1960 model year called "Panelescent Lighting".

See also

In Spanish: Electroluminiscencia para niños