What is the use of LED 1

How an LED works

Info world energy

Energy-efficient, flexible and robust: light-emitting diodes not only displace light bulbs, they also change the future of lighting.

Electric light in perfection

We already know how an LED works from the animal world. To put it bluntly, the energetic firefly, for example, is a flying LED. The only difference is how the atoms inside are excited and thus made to glow. The fireflies do this through a chemical reaction. With LEDs, this happens with the help of electrical current - in short: electroluminescence.


"Energy-efficient future of lighting: LEDs have replaced conventional light bulbs."

Simply explained: The LED functionality

A light emitting diode consists of an anode and a cathode. A wire, the so-called bond wire, ensures the flow of current between the two poles. The energy required for the desired electroluminescence flows through this.

A chip sits on the cathode and is surrounded by a plastic lens that protects the chip and distributes the light in the room. The chip used to generate light is placed in what is known as a reflector trough, which achieves a good light yield and high efficiency.

The chip is a semiconductor crystal made of two different materials that are doped differently. This means that there is an excess of positive or negative charge carriers. If current flows, the electrons react and energy is released in the form of photons. The LED lights up.

Five advantages of the LED at a glance


Very low power consumption


High luminous efficacy without a start-up phase


Easy exchange / change thanks to uniform versions


Does not contain any substances that are hazardous to health, such as mercury

Experts watch out! The variety of LEDs

Not all LEDs are the same. There is a suitable solution for every application. We present two variants with which you can expand your expert knowledge on the subject of light emitting diodes.


These are intended for industrial, but also for residential lighting. The semiconductor chip and a heat sink form a unit that can be attached to a printed circuit board. SMD LEDs offer the possibility of producing very individual, bright lights.


Here the semiconductor crystal is glued directly to the circuit board and connected with two bonding wires. This has advantages in terms of heat dissipation and enables a dense construction, since additional heat sinks can be smaller. As a result, a lot of light can be achieved in a very small space. For this reason, COB LEDs are also favorites with lighting manufacturers. Typical applications of COB LEDs are spotlights, round ceiling lights or decorative lamps.

You can find out more about the properties of LEDs and how to correctly read the packaging of an LED lamp in the article How to read the packaging of an LED. Are you still looking for an extraordinary LED lamp for home and garden? Let yourself be inspired by our intelligent lighting solutions in the Vattenfall Shop!

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Read the packaging of an LED

The LED is an alternative to the light bulb and the energy-saving lamp. It has a longer lifespan and uses up to 80 percent less electricity than light bulbs. But there are also differences with LEDs.

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Photos: 1) onurdongel / iStock.