Light Emitting Diode (LED)

A Light Emitting Diode (LED) is a diode that emits light when electric current flows through it.

• Context:
  • It operates on the principle of electroluminescence, where electrons recombine with electron holes within the device, releasing energy in the form of photons.
  • It can have a specific color of the light produced by an LED is determined by the energy band gap of the semiconductor material used.
  • It can (typically) consist of a two-lead semiconductor light source.
  • It can (often) be used in a wide range of applications, from indicator lights in electronic devices to street lighting and automotive headlights.
  • It can (typically) offer advantages over incandescent light sources including lower energy consumption, longer lifetime, improved physical robustness, smaller size, and faster switching.
  • It can (often) have variations including high-power LEDs for illumination, miniature LEDs for electronic devices, and organic LEDs (OLEDs) for displays.
  • ...
• Example(s):
  • Red LEDs used as indicator lights on electronic devices.
  • Yellow LEDs ...
  • Blue LEDs used in creating white light in combination with phosphors.
  • White LEDs used in home and commercial lighting solutions.
  • ...
• Counter-Example(s):
  • Incandescent Light Bulb, which produces light by heating a wire filament.
  • Fluorescent Lamp, which produces light through the excitation of mercury vapor.
• See: Photodiode, Electroluminescence, H. J. Round, Oleg Losev, James R. Biard, Nick Holonyak, Anode, Cathode, Semiconductor, Electronics, Organic Light-Emitting Diode (OLED), Phosphor, Visible spectrum, Infrared light, Ultraviolet light.

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References

2024

• (Wikipedia, 2024) ⇒ https://en.wikipedia.org/wiki/Light-emitting_diode. Retrieved:2024-2-9.
  • A light-emitting diode (LED) is a semiconductor device that emits light when electric current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy in the form of photons. The color of the light (corresponding to the energy of the photons) is determined by the energy required for electrons to cross the band gap of the semiconductor. White light is obtained by using multiple semiconductors or a layer of light-emitting phosphor on the semiconductor device. LEDs were first introduced as practical electronic components in 1962, emitting low-intensity infrared light. They have since been developed to emit light in the visible, ultraviolet, and infrared wavelengths with varying intensity levels. LEDs are used in a wide range of applications, including aviation lighting, automotive headlamps, advertising, general lighting, traffic signals, and medical devices. LEDs offer several advantages over incandescent light sources, such as lower power consumption, longer lifetime, improved robustness, smaller size, and faster switching, though they also have some disadvantages, including electrical limitations and sensitivity to temperature.