Related topics: light

A new LED design for next-level realism in immersive displays

From pterodactyls flying overhead in a game to virtually applying cosmetics prior to making a purchase, augmented reality and other immersive technologies are transforming how we play, observe, and learn. Cheap and ultra-small ...

Simple ballpoint pen can write custom LEDs

The invention of the printing press revolutionized duplication of the written word, giving the hands of tired scribes a break and making written material more accessible. A similar breakthrough has happened in reverse in ...

Clever fly offers lessons on advanced predator adaptations

The saffron robber fly (Laphria saffrana) is an extremely fast bee-colored hunter that has to determine, while perched, which insects it wants to chase and eat. This is complicated by the fact that its eyes have poor resolution, ...

Progress in perovskite LEDs for deep-blue light

The deep blue of your LED display is likely produced by indium gallium nitride (InGaN), a costly substance. In the field of LEDs, researchers are seeking alternatives in a type of perovskite known as quasi-2D Ruddlesden‒Popper ...

LED tech boosts saplings, hopes for UK net zero bid

Surrounded by rows of healthy saplings grown using the latest LED technology, Scottish forestry researcher Kenny Hay has been left in little doubt that the science can boost Britain's net zero efforts.

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Light-emitting diode

A light-emitting diode (LED) (pronounced /ˌɛliːˈdiː/, or just /lɛd/), is an electronic light source. The LED was first invented in Russia in the 1920s, and introduced in America as a practical electronic component in 1962. Oleg Vladimirovich Losev was a radio technician who noticed that diodes used in radio receivers emitted light when current was passed through them. In 1927, he published details in a Russian journal of the first ever LED.

All early devices emitted low-intensity red light, but modern LEDs are available across the visible, ultraviolet and infra red wavelengths, with very high brightness.

LEDs are based on the semiconductor diode. When the diode is forward biased (switched on), electrons are able to recombine with holes and energy is released in the form of light. This effect is called electroluminescence and the color of the light is determined by the energy gap of the semiconductor. The LED is usually small in area (less than 1 mm2) with integrated optical components to shape its radiation pattern and assist in reflection.

LEDs present many advantages over traditional light sources including lower energy consumption, longer lifetime, improved robustness, smaller size and faster switching. However, they are relatively expensive and require more precise current and heat management than traditional light sources.

Applications of LEDs are diverse. They are used as low-energy indicators but also for replacements for traditional light sources in general lighting and automotive lighting. The compact size of LEDs has allowed new text and video displays and sensors to be developed, while their high switching rates are useful in communications technology.

This text uses material from Wikipedia, licensed under CC BY-SA