A light-emitting diode (LED) is a semiconductor device that emits light when an electric current is passed through it. Light is produced when the particles that carry the current (known as electrons and holes) combine together within the semiconductor material. Since light is generated within the solid semiconductor material.
Since light is generated within the solid semiconductor material, LEDs are described as solid-state devices.
The color of light depends on the semiconductor material used in manufacturing the diode and can range from ultraviolet (UV), through visible light, to infrared (IRED).Until the mid-90s LEDs had a limited range of colors, and in particular commercial blue and white LEDs did not exist. The development of LEDs based on the gallium nitride (GaN) material system completed the palette of colors and opened up many new applications.
The main semiconductor materials used to manufacture LEDs are:
- Indium gallium nitride (InGaN): blue, green and ultraviolet high-brightness LEDs
- Aluminum gallium indium phosphide (AlGaInP): yellow, orange and red high-brightness LEDs
- Aluminum gallium arsenide (AlGaAs): red and infrared LEDs
- Gallium phosphide (GaP): yellow and green LEDs
The first LED was developed in 1927, but was not used in the industry until the sixties. In 1996, a white LED of 5 lm / W efficiency was achieved in laboratory. Currently, in production, LEDs yield above150 lm/W.
LEDs are used in all kinds of indicator lights (on / off), signaling and information boards. They are also used in the manufacture of liquid crystal displays for computers, mobile phones, televisions, etc.
LED use is becoming more common and is likely to increase in the future as it has an efficiency of 150 lm / W which is 11.5 times higher than incandescent lamp (13 lm / W), 1.7 times higher than fluorescent lamps (90 lm / W) and even higher than high pressure sodium lamps (132 lm/W).
Advantages of LED lighting
They are safer than traditional lighting, because they are less polluting: do not contain mercury or tungsten. By using them we reduce CO2 emissions by 80%.
Longer lifetime: more than 70,000 hours of use (more than 15 years, if we light about 8 hours a day), they have minimal maintenance.
It does not generate heat, they do not burn when touched (80% of the energy consumed is converted into light, unlike the traditional incandescent bulbs, which waste the same percentage as heat).
Energy savings (consuming up to 85% less than traditional bulbs).
Resists more extreme temperatures than incandescent, and higher humidity and vibrations.
Resists a huge number of cycles without affecting its performance (when turned on and off) esistant
Great fidelity in color rendering, with a color index of 95 out of 100. It also has different shades of light (cold, warm) to fit any space.