In addition to laser lighting, "the father of blue light" recently busy?

Due to the transformation of metal organic chemical vapor deposition (MOCVD) machine for double flow, creating a highly efficient blue light emitting diode, lighting and light display changed the future, Dr. Nobel prize winner Nakamura Shuji was praised as "the father of blue light", in 2017 February to Taiwan Central Research Institute of speech, "The Invention of High Efficient Blue LEDs and Future Solid State Lighting", a small boy immediately after that booked a ticket to Taiwan on the Mars space to blue Godfather style.

In a speech in the village said professor continued how to make higher color rendering and higher external quantum efficiency (EQE) in the study of the light emitting diode, improve the color rendering, can enhance lighting applications or display color; and the external quantum efficiency is higher, can improve the luminous efficiency of the device. Of course, in the middle of the professor also talked about some of the advantages of laser lighting, this we mention.

First review the history of blue light, the time came in 1980s, when the blue light device has two kinds of material selection, one is ZnSe; another is GaN, from Cross section TEM can be observed in the ZnSe growth have good quality, because of defects in the GaN/Sapphire can see a black line is often talk about in a semiconductor device, he is one of the murderers has great influence on the efficiency of the device. In 1989s, ZnSe on GaAs substrate crystallization properties of high quality at the same time, there are more than 99% researchers engaged in related research work, in the village of Professor chose less than 1% of the Chinese GaN on Sapphire substrates, at that time, many people say that GaN has no future, have switched to the arms of the ZnSe, said in the selection the village is the "draw further apart".

You little boy at that year, once with the children in laboratory experiments, in which a topic is to study the basic physical properties by using MOCVD ZnSe and ZnSe QW to grow out of the QD semiconductor devices, really don't cheat, everybody in the PL experiment, the light path also deliberately not to light on into the detector. The detector can receive the strength to avoid over, this is how extravagant baggage ah! So why ZnSe can attract mainstream attention.

As for how Nakamura Shuji GaN wins, deviant, is the story of everyone for having heard it many times.

The speech also said that many people worry about the blue damage, although the small servant will say simple question this is only "a person can accept how much", but Nakamura Shuji did not ignore the voice of the mainstream, engaged in the development of Blue-free at the University of California, Santa Barbara, team LED, to solve the problem of speech and blue, in the village that will be the main light emitting layer is mainly moved to the UV section, the general LED grew up on the sapphire substrate (some R & D technology is the use of SiC substrate and Si substrate), however, in order to reduce the lattice mismatch of the drop in stress effect will cause the internal quantum efficiency and external quantum efficiency, in the village of R & D the team is devoted to the study of the use of GaN substrate, to enhance the quality of crystal lattice matching degree, compared to the Sapphire or SiC substrate are too high.

Nakamura Shuji founded the company Soraa, also to the UV-LED direction, in order to do this, they will light purple peak design in 410nm ~ 420nm between GaN and LED, the multi collocation phosphor mixture, white light spectrum coverage to 700nm, which said the whole spectrum of white light will cover the visible wavelength range (general the human eye, but the scope is about 400nm ~ 700nm), (400nm) from purple to deep red (700nm) is continuous and complete, the advantage of this is that users can see the real white.

In his speech, in the village also noted that, using LED as the white light is great, but if the laser is a better idea, because the current LED structure of the incandescent lamp to light emitting 60W, need about 28mm^2 area arrangement with current LED, incandescent lamp and the laser products the product of their research to the luminescence of 60W requires approximately 0.3mm^2 of the area, the area is greatly reduced.

At the same time if the use of laser devices after the increase in the current density, the external quantum efficiency should not drop too much! This is a matter of how much ah (here we recommend to read the world first simple semiconductor science hall principle of old leaves (five)), because from the semiconductor device physics can know LED or LD the current density increased, although more and more bright, but will cause the emission peak redshift and external quantum efficiency decreased, which is decreased due to thermal effects caused by the lattice vibration, therefore in flat-panel display or lighting applications will be more diverse.

In the speech, the wireless optical communication technology "Li-Fi" is also the Nakamura Shuji value technology, Li-Fi is the use of light emitting diode or laser device as a source of data transmission. So imagine one thing, the lamp is the base station of communication, the signal will be projected to the bridge and everywhere, so that computers, home appliances, mobile phones and other Internet access. Nakamura Shuji also mentioned that if the use of light emitting diode Li-Fi, will be more than 10 times faster than Wi-Fi transmission data, while the laser device Li-Fi faster. But the small servant thought, if the work off, there is no Internet! So time to be office.

At the end of the speech in the village of professor mentioned in the flat panel display technology, LED and OLED can still maintain the competition, particularly the u-LED technical direction is possible, as for the future of the u-LED, a small servant will