Nakamura Shuji interpretation of the next generation of solid-state lighting technology

According to science news reports, the Nobel physics prize winner Nakamura Shuji, September 3, 2015 invited to Taiwan speech, share their own research and development of high brightness blue light-emitting diode (LED) technology development, key development trends and the next solid-state lighting technology.

When talking about the end of 1980s, the village began to study the blue LED, the material selection encountered great challenges. There are two main types of time may achieve the blue LED materials are zinc selenide (Zinc Selenide, ZnSe) and GaN (Gallium Nitride GaN).

The village repair two "new bright road" speech

In or out of the ordinary is not optimistic, insist on

At that time, GaN almost no what good, because the GaN and sapphire substrate lattice mismatch, the crystal defect density of 1 x above 109 cm-2, the quality is far less than ZnSe, so there are as many as 99% researchers, have chosen to do research on ZnSe material for spell map blue LED the related research papers are numerous.

But the village is just the opposite of its way, adhere to the road with others not the same, choose only 1% people concerned about the material GaN. In the village the unlikely decision to change life, just as his personal writings in "my thoughts, my light" (in the forms of test force, this force, provided on the of private methods) said, "as I met and blue light emitting diode wonderful. Everyone's life will encounter unbelievable".

Achieve high brightness blue LED, InGaN power can not be

In order to improve the problem of lattice mismatch between GaN and sapphire substrate, in the village with the material of GaN buffer layer on sapphire substrates (Buffer Layer), and to modify the gas flow (Two-Flow) metal organic chemical vapor deposition (MOCVD) device, epitaxial quality significantly improved, but also laid the foundation for the realization of high the brightness of blue LED.

MOCVD assisted in double flow, in the village by thermal annealing process (Thermal Annealing), the effective implementation of p layer GaN; later, successful growth of key materials of InGaN achieve high brightness blue LED (Indium Gallium Nitride, InGaN), and with InGaN as the light-emitting layer between p layer and GaN n GaN, a double heterojunction structure (Double Heterostructure), improve the original p-n homojunction (Homojunction) of the LED luminous efficiency, high brightness blue LED.

InGaN to produce high brightness blue, LED blue and violet semiconductor laser diode laser, are indispensable roles, in the village is so called "magic materials", but the Nobel prize award at the description of the contribution to InGaN did not mention, but also to the village more than once expressed regret in the heart.

"Nakamura Shuji and the same as the 2014 Nobel physics prize winner Akasaki Yong (Isamu Akasaki), Amano Hiroshi (Hiroshi Amano), the implementation of LED in blue contribution

Next generation lighting trends, focusing on GaN on GaN, LD Technology

As for the next solid state lighting technology trends, in addition to making use of "GaN on GaN LED purple" technology, and then produce more pure luminescence consistent, uniform white light, in the village also pointed out that the laser lighting will be the key of industrial development. Compared to LED, Diode (Laser, LD) to achieve more efficient lighting, the village believes that LD in the near future will be quite a market.

In the village is not affected by the traditional framework of bondage, the courage to challenge, perseverance and never give up personality, let him in the face of numerous failures still struggling to move forward, the process for the later success laid the cornerstone, also achieved success today, made great contribution to human life, profound influence.

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