Nitride Semiconductors Launches Micro LED Company
Japanese UV-LED pioneer Nitride Semiconductors has formed a 100 percent owned subsidiary called Micro Nitride. The new company will develop and sell micro UV LED chips for micro LED displays, based on a new patent-pending technology. The business has a total capital of 100 million Yen (50 million of which is reserve).
Currently there are two ways to make micro LED displays: the three LED type using three red, blue, and green; and the blue LED excitation type exciting red and green phosphors.
WIth the three LED type, it is impossible to produce μ red chips because its material is fragile, furthermore it is difficult to mount LED chips of different colours with different structures at high density. Their current and voltage, reaction speeds are different, so there is a problem controlling each chip.
In contrast, the μ Blue LED excitation method can integrate all mounted LED chips into μ blue LEDs, so the difficulty of mounting decreases and the current and voltage can also be unified. But the blue light is emission, whereas the red light and the green light are excitation. This means there is a time lag of reaction speed, and there is another problem that the colour reproducibility is low because of the low luminance of red and green due to blue excitation.
Micro Nitride is developing an alternative technology called μUV-LED+RGB phosphor to solve the problem. It found that the luminous efficiency is doubled when fabricating μUV-LED chip with SLS structure in both n and p layer. (Patent pending)
The reason is that since the distance of the diffusion current is short, the light emission recombination increases and the internal quantum efficiency improves and the distance from the light emitting layer to the outside become short, the external quantum efficiency improved.
The parent company Nitride Semiconductors began life in 2000 as a start-up from Tokushima University, where the founders developed the world's first UV LED. The company developed 100nm shorter light emitting than blue LED and has a lot of core technologies of crystal growth.