Scribd
Upload
32 views2 pages

Semiconductor Light Source Current Electrons Electron Holes Photons Electroluminescence

An LED is a semiconductor device that emits light when electric current passes through it. Electrons are able to cross the band gap of the semiconductor material when stimulated by electricity, releasing photons. The color of the light depends on the band gap energy of the semiconductor. White light can be produced using multiple semiconductors or a phosphor layer. LEDs have advantages over incandescent bulbs like lower energy use, longer lifetime, and smaller size. They are used in many applications including displays, lighting, and cameras.

Uploaded by

Love boy mittal ji Lakshay
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as DOCX, PDF, TXT or read online on Scribd
32 views2 pages

Semiconductor Light Source Current Electrons Electron Holes Photons Electroluminescence

An LED is a semiconductor device that emits light when electric current passes through it. Electrons are able to cross the band gap of the semiconductor material when stimulated by electricity, releasing photons. The color of the light depends on the band gap energy of the semiconductor. White light can be produced using multiple semiconductors or a phosphor layer. LEDs have advantages over incandescent bulbs like lower energy use, longer lifetime, and smaller size. They are used in many applications including displays, lighting, and cameras.

Uploaded by

Love boy mittal ji Lakshay
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as DOCX, PDF, TXT or read online on Scribd
You are on page 1/ 2

LED

A light-emitting diode (LED) is a semiconductor light


source that emits light when current flows through
it. Electrons in the semiconductor recombine with electron
holes, releasing energy in the form of photons. This effect
is called electroluminescence. 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.
Appearing as practical electronic components in 1962, the
earliest LEDs emitted low-intensity infrared light.Infrared
LEDs are used in remote-control circuits, such as those
used with a wide variety of consumer electronics. The first
visible-light LEDs were of low intensity and limited to red.
Modern LEDs are available across the visible, ultraviolet,
and infrared wavelengths, with high light output.
Early LEDs were often used as indicator lamps, replacing
small incandescent bulbs, and in seven-segment displays.
Recent developments have produced white-light LEDs
suitable for room lighting. LEDs have led to new displays
and sensors, while their high switching rates are useful in
advanced communications technology.
LEDs have many advantages over incandescent light
sources, including lower energy consumption, longer
lifetime, improved physical robustness, smaller size, and
faster switching. Light-emitting diodes are used in
applications as diverse as aviation lighting, automotive
headlamps, advertising, general lighting, traffic signals,
camera flashes, lighted wallpaper and medical devices.
Unlike a laser, the color of light emitted from an LED is
neither coherent nor monochromatic, but the spectrum is
narrow with respect to human vision, and functionally
monochromatic

You might also like