For 10 long years after his employer ordered him to give up, Shuji Nakamura toiled away on his own, single-mindedly pursuing his dream of achieving a bright blue light from an LED… It had to be blue, because red and green had been around for decades, and he realised “with adding the blue, you could have all the primary colors and thereby the entire palette”.
Nakamura had graduated from the University of Tokushima in 1977 with a degree in electronic engineering, and a master’s degree in the same subject two years later. Two other scientists, Isamu Akasaki and Hiroshi Amano, had contributed to the progress of LED technology when they invented their dim blue light-emitting diodes. Then they moved on, went separate ways, but Shuji Nakamura wouldn’t give up.
In 1993, Nakamura finally cracked the fabrication challenges to get the first high brightness gallium nitride (GaN) LED that was commercially viable. He went on to partially convert it to yellow by a phosphor coating, and it became the key to white LED lighting, which went into production in 1993.
After successfully manufacturing these white LEDs in 1994, Nichia went on to develop commercialized green LEDs the following year, and laser diodes (LD) in 1999.
The company was reported to have only given Nakamura $180 for his blue GaN LED invention, so he left the company and went to the USA.
After Nakamura left Nichia in 1999 he sued them claiming that he had not been adequately compensated for his role in helping the company to become the world’s leading supplier of blue and white LEDs, as well as the violet lasers that are used in next-generation DVD systems. During his tenure at Nichia, Nakamura filed a huge number of patents relating to all aspects of nitride LED technology.
The three scientists received the Nobel Prize in Physics on 7 October 2014 for their priceless efforts. The Nobel Prize committee cited the development of the blue LED as leading to a new, more efficient, and environmentally friendly way “to illuminate the world.”
Frances Saunders, president of Britain’s Institute of Physics, said the shift to LED offered the potential for huge energy savings. “With 20% of the world’s electricity used for lighting, it’s been calculated that optimal use of LED lighting could reduce this to 4 percent. Akasaki, Amano and Nakamura’s research has made this possible and this prize recognises this contribution,” she said.
LEDs, often referred to under Solid State Lighting, are constantly improving in efficiency, with higher luminous flux (lumens) per unit electrical input power (watts). In 2015 experimental LED’s had achieved over 300 lumens per watt, which can be compared to 16 lumens for regular light bulbs and close to 70 lumens for fluorescent lamps.
The western world has long since forgotten the way it transformed after the “electric light’ became so widely available following Edison’s invention in 1879, and his famous boast, “We will make electricity so cheap that only the rich will burn candles.”
But now LED lighting also holds similar great promise for the 1.5 billion people around the world who lack access to electricity grids: due to low DC power required, LED can be run by solar powered systems.
And so LEDs continue to make a massive contribution to saving the Earth’s resources and elevating the living standards of future generations.