Light-emitting diodes (LEDs) are semiconductor devices that emit light when an electric current passes through them. The history of LEDs dates back to significant discoveries in the early 20th century, with notable contributions from researchers like Oleg Losev, Georges Destriau, and Rubin Braunstein. Losev reported the creation of the first LED in 1927, while Destriau observed electroluminescence in zinc sulphide powder in 1936. Braunstein demonstrated infrared emission from gallium arsenide in 1955, paving the way for LED applications in optical communication.
The working principle of LEDs involves electrons recombining with electron holes within the semiconductor material, releasing energy in the form of photons. The color of light emitted by an LED is determined by the energy required for electron transitions. Initially developed in 1962, early LEDs emitted low-intensity infrared light and were primarily used as indicator lamps and in displays. Over time, advancements led to LEDs available in various wavelengths, including visible, ultraviolet, and infrared, with high efficiency and light output.
LED technology has revolutionized lighting applications due to its numerous advantages over traditional incandescent sources. LEDs consume less power, have a longer lifespan, are physically robust, compact in size, and offer faster switching capabilities. These characteristics have enabled LEDs to be used in a wide range of applications, such as room lighting, outdoor illumination, automotive headlamps, traffic signals, and medical devices. Additionally, LEDs have facilitated the development of new display technologies and sensors.
Understanding LED types is crucial for optimizing their performance. Two common types are 5mm Through-Hole LEDs and Surface Mount LEDs (SMD). Through-Hole LEDs are suitable for applications requiring lower light output and run at lower drive currents compared to SMD LEDs. On the other hand, SMD LEDs are mounted on substrates with a silicon dome over the diode for enhanced performance. High-power SMD LEDs from reputable manufacturers like Cree and Luxeon offer superior efficiency and illumination.
Powering LEDs safely is essential to maximize their light output and longevity. An LED functions as a diode that emits light when electricity flows from the anode to the cathode. Proper current regulation is crucial to ensure optimal performance and prevent damage to the LED. Understanding drive currents and selecting appropriate drivers based on LED specifications are key factors in powering LEDs effectively.
In conclusion, the evolution of LED technology has transformed the lighting industry by offering energy-efficient, durable, and versatile lighting solutions across various sectors. From humble beginnings as indicator lamps to sophisticated lighting applications in modern times, LEDs continue to play a vital role in advancing illumination technology towards a more sustainable and efficient future.
- https://en.wikipedia.org/wiki/Light-emitting_diode
Title: Light-emitting diode – Wikipedia
Summary: This page provides a comprehensive overview of light-emitting diodes (LEDs), including their physics, history, applications, and advantages over other lighting technologies. It explains how LEDs work, how they are made, and how they emit light. It also covers the different types of LEDs, such as organic LEDs and quantum dot LEDs, and their use in various fields, such as lighting, displays, and communications. - https://simple.wikipedia.org/wiki/Light-emitting_diode
Title: Light-emitting diode – Simple English Wikipedia, the free encyclopedia
Summary: This page provides a simplified explanation of what light-emitting diodes (LEDs) are and how they work. It explains that LEDs are semiconductor devices that produce light from electricity and that they are more durable and energy-efficient than other types of lighting. It also covers some of the applications of LEDs, such as in traffic lights and electronic devices. - https://en.wikipedia.org/wiki/LED_lamp
Title: LED lamp – Wikipedia
Summary: This page provides information on LED lamps, which are electric lights that produce light using light-emitting diodes (LEDs). It explains how LED lamps are more energy-efficient and longer-lasting than other types of lamps, such as incandescent and fluorescent lamps. It also covers the different types of LED lamps, such as directional and omnidirectional lamps, and their use in various settings, such as homes, offices, and outdoor areas. - https://en.wikipedia.org/wiki/Light-emitting_diode_physics
Title: Light-emitting diode physics – Wikipedia
Summary: This page provides a detailed explanation of the physics behind light-emitting diodes (LEDs), including how they produce light through electroluminescence and how their efficiency can be affected by various factors, such as temperature and current density. It also covers the different materials used to make LEDs and how their properties affect the color and efficiency of the emitted light.