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LED type development
- Jul 31, 2017 -

The first application of 

semiconductor P-N junction light principle made of LED light source came out in the early 20th century, 60 years. At that time the material used was GaAsP, red light (λp = 650nm), the drive current of 20 mA, the luminous flux is only a few thousand lumens, the corresponding luminous efficiency of about 0.1 lumens / watt.

In the mid-1970s, the elements In and N were introduced to make the green light (λp = 555nm), yellow (λp = 590nm) and orange (λp = 610nm), and the luminous efficiency was also increased to 1 lumen / watt.


To the early 80s

there GaAlAs LED light source, making the red LED light efficiency of 10 lumens / watt.


In the early 1990s

the red light, yellow GaAlInP and green, blue GaInN two new materials developed successfully, so that the LED light efficiency has been greatly improved. In 2000, the former made of LED in the red, orange (λp = 615nm) of the luminous efficiency of 100 lumens / watt, while the latter made of LED in the green area (λp = 530nm) of the luminous efficiency can reach 50 lumens / watt.


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