Introduction to LED and its applications:
LED’s are luminous diodes or luminous diodes that are widely used in domestic and industrial industries. In different references, LED is also called light emitting diode.
The first industrial production LED’s were released in 1962 with only red (combination of aluminum, gallium and arsenide) and a variety of green, blue, yellow and orange LED’s were also produced and imported in the 1970s.
were marketed. The optical power of LED’s gradually increased until in the 1980s and early 90s, LCDs entered the market in groups with very high performance. Primary LED due to interest The optical power of today’s white LEDs is up to 70 lumens per watt and colored LEDs up to 50 lumens per watt, and is projected to be up to 200 lumens per watt as well.
Leds are solid-state emitting light demons that convert electrical energy directly into light of a color, light generation technology in LEDs (cold light) where most energize in the visible spectrum.
The color of the light produced by led lighting sources is generally located in the area (white light) and the color temperature of 2700k-6500k from hot white to cool white.
White light is actually made of all colors of the rainbow because it holds the entire wavelength spectrum and it is referred to as multicolored light.
It is not possible to produce white light color in led directly.
Unlike white LED light, it is very efficient in producing pure color light because it is possible to extract their total light output at the same wavelength.
Building and LED performance:
The color of led light depends on the crystal material of their constituents and by changing the physical structure and led ingredients of light in different colors and intensities and with specified wavelengths with pure color
LeDs are composed of composite semiconductor materials composed of elements of group III and group V of periodic table.
Examples of III-V materials commonly used for LED manufacturing include Gallium arsenide GaAs and Gallium Phosphide GAP
When two elements of the two adjacent groups of the periodic table are put together, especially if doping is doping, their different energy levels cause band gap formation. Actually inside the led semiconductor material
Electrons and holes are located in energy bands known as conduction and capacity bands.
The wavelengths of visible light are:
Blue: 450-495 nm
Purple light has the lowest wavelength, meaning that it has the highest frequency and energy, red has the longest wavelength, lowest frequency and lowest energy.
The main theme for the production of any color from the visible spectrum is that it is possible to find a combination of group IV elements (semiconductors) with elements of adjacent groups i.e.
group III and V, which is the EG energy equivalent to the wavelength of the desired light.
The main semiconductor materials used today in the manufacture of LEDs are:
Ingan’s Gallium Indium Nitride (LEDs): LED) High Blue-Green and Ultraviolet Lighting
Phosphide Gallium Indium ALGALNAP) : RED AND INFRARED LEDs
Gallium PhosphideGAP(:Yellow and Green LEDs)
LED’s currently cover the entire spectrum of light, including red, orange, yellow, green, blue and white. Although colored light is useful for more creative installations, white light remains the grave of sacred LED technology
Production of color light with LED:
The first commercially usable LEDs were produced in the 1960s by combining three main elements: gallium, arsenic and phosphorus to be acquired.
With the advancement of LED technology until the 1970s additional colors and wavelengths became available.The most common materials gap green and red, orange GAASP or high performance red and yellow GAASP were
All are still in use today.
White light generation:
The easiest way to produce white light is to integrate three separate LEDs emitting the three main colors of red, green and blue in a LED. In this method, firstly, the efficiency is low, secondly the quality
The white color is low due to the lack of spectrum coverage and the presence of three completely separate peaks.
The blue LED was the last breakthrough needed to شwhite LED scientists use to make white LED from blue light to stimulate a fluorescent chemical and build white light