You may have noticed that there are many different types of lights surrounding you every day. In your table lamp at home, there may be a regular light bulb — what scientists call an incandescent bulb. There are many other types of lights, though, that contain LEDs.
LEDs — or light-emitting diodes — are found in all sorts of things. For example, the numbers on your digital clock are formed by LEDs. Your television remote control probably uses LEDs to send signals. LEDs can light up wristwatches and traffic lights. Your television might also be powered by LEDs!
But what exactly are LEDs? The science behind LEDs can get really complicated, but basically they're like tiny light bulbs that are part of a simple electrical circuit. They're different from regular light bulbs, though, because they don't get very hot and they don't have a filament that will burn out. These features make LEDs very popular for many products.
LEDs are illuminated by the movement of electrons across a semiconductor material, such as aluminum-gallium-arsenide (AlGaAs). The movement of the electrons causes the release of light, which can then be directed outward by the shape of the LED bulb.
Regular light bulbs often burn out after a few hundred hours of use (or less), but LEDs can last for thousands of hours. In fact, some LEDs can last 50,000 hours or more!
LEDs have many other advantages. For example, LEDs tend to be more durable than regular incandescent light bulbs. They also fit more easily into electric circuits. LEDs are much more efficient than regular light bulbs, since a higher percentage of the electrical power goes to generate light rather than heat.
The cost of semiconductor material can make LEDs more expensive than regular incandescent light bulbs. However, their efficiency, durability and extended life usually make them a much better bargain in the long run.
Although LEDs are all the rage these days, they've actually been around for a while. American Nick Holonyak, Jr., created the first LED in 1962.