NEW LIGHTING ILLUMINATING THE WORLD-BLUE LEDs

by Manuel Reali and Mohammed Zia Ullah Khan,
PhD candidates at Polytechnique School of Montreal

DEDICATION, PASSION, IMAGINATION AND COOPERATION:
THE SQUARE OF THE SUCCESS

October 7th, 2014, 1.18 pm: Isamu Akasaki, Hiroshi Amano and Shuji Nakamura are officially proclaimed Nobel Prize winners for having invented blue light-emitting diodes by the Royal Swedish Academy of Science.

Light-emitting diodes are doped semiconductors’ based materials currently known as  the highest efficiency source of light emission. The structure is simple: an n and p-type semiconductor, material with an excess of negative and positive charges respectively, are interfaced to form a classic diode where in between, an active layer is placed to favour the recombination (or annihilation) of the charges upon the application of an external electric field. Recombination of electrons (-) and holes (+) produces a photon emission of a given wavelength.

 Since the first discovery of the semiconductors-light emitters, the smart idea of  combining red, green and blue emissions to get white light emission, started to actively circulate within the scientific communities. By achieving this dream, a huge amount of energy would have been saved compared to the classical sources of illumination. Scientists were indeed already aware of the potential lower consumptions, brilliant lights and 100x higher stability over the time compared to light bulbs or fluorescent light sources.

“Revolution is the consequence of dedication...
and cooperation!”

While red and green LEDs have been successfully achieved over the years, blue one constituted the main obstacle. Before the discovery of Akasaki, Amuno and Nakamura, GaN was already known as a good semiconducting material able to emit blue light but nobody before them was able to find a fabrication method to get highly and sufficiently purified GaN crystals to achieve the objective.

After over 20 years of hard work, they finally reached the aim! It has been told about nights and nights spent in the laboratories to try and try. 

Your research can bring a considerable impact on the society only if your passion moves your intentions and aims.

The discovery of blue light-emitting diodes is really revolutionary and it has already had a great impact on our everyday life!

Blue is a primary color and its combination with the other two primary ones brought, in addition to white light emitting diodes, to the fabrication of multicolor-chips for TV, tablet and mobile phone screens.  

How big is the impact? A classical light bulb converts only 4% of electricity into light, while a white LED up to 50!!!

THE STORY INTO THE STORY:
THE NAKAMURA’S BATTLE YOU SHOULD KNOW

Behind the astonishing discovery of blue LEDs and the efficient fabrication of new white light emitting LEDs, there is a story of suffering, pain, unrecognized rights and... justice!

Nakamura started to develop the GaN LEDs in Nichia company which earned several million of US$ selling LEDs made by Nakamura’s research group patents.

When Nakamura decided to leave the company in 1990s, Nichia gave him only 180 US$ in compensation of his invention!

You may think “scientists do not bring up the research for money” and that is absolutely true but his dedication, passion and creativity deserve to be respected and awarded.

Fight everyday of your life to get your work and passion valued. If you want to respect people around you, respect yourself firstly.

Nakamura then decided to legally pursue Nichia in 2001 claimed to be the holder and the inventor of LED patent. That time, many colleagues used to called him “slave Nakamura” to don’t forget the awful treatment that Nichia reserved to him!

The scientist asked to be payed 180 million US$ for the work accomplished in Nichia and to protect his patent. Initially, the Court of Japan ruled Nichia to pay Nakamura 20 billion of Japanese Yen and the greed Company made an appeal.

The final judgment made Nakamura the winner stated that Nichia should have payed 844 million of Japanese Yen! Avidity and ungrateful condemned Nichia to refund him with a much larger amount of money he asked in the beginning.

This story into the story tells us that if you know you’re fighting for a right cause, you will never lose because the world is made of connections of people.

Sometimes you can feel yourself robbed of your dignity as a human being but you have to be conscious that there is always someone ready to give it back to you.