Blue LED Inventors Nab Nobel Prize

Two Japanese scientists and an American who invented the 'revolutionary' blue light-emitting diode (LED) two decades ago have been awarded the Nobel Prize for Physics.

Isamu Akasaki, Hiroshi Amano, and Shuji Nakamura 'triggered a fundamental transformation of lighting technology' when they succeeded in producing 'bright blue light beams from their semiconductors in the early 1990s,' the Royal Swedish Academy of Sciences wrote Tuesday in an announcement of the honor.

The accomplishment built upon the earlier creation of red and green diodes by others, paving the way for the use of blue LEDs in white lamps which are many times more efficient and durable than incandescent and fluorescent bulbs, the academy noted.

'Despite considerable efforts, both in the scientific community and in industry, the blue LED had remained a challenge for three decades. They succeeded where everyone else had failed,' the announcement said.

The Nobel committee singled the trio out for 'revolutionary' invention which 'has already contributed to create white light in an entirely new manner to the benefit of us all.'

'White LED lamps emit a bright white light, are long-lasting, and energy-efficient,' the committee said. 'They are constantly improved, getting more efficient with higher luminous flux (measured in lumen) per unit electrical input power (measured in watt).

'The most recent record is just over 300 lm/W, which can be compared to 16 for regular light bulbs and close to 70 for fluorescent lamps. As about one fourth of world electricity consumption is used for lighting purposes, the LEDs contribute to saving the Earth's resources. Materials consumption is also diminished as LEDs last up to 100,000 hours, compared to 1,000 for incandescent bulbs and 10,000 hours for fluorescent lights.'

Akasaki, born in 1929 in Chiran, Japan, is a professor at the University of Nagoya, where he worked on blue LEDs with his colleague Amano, who was born in 1960 in Hamamatsu, Japan. Nakamura, born in 1954 in Ikata, Japan, is now an American citizen and a professor at UC Santa Barbara who was working at Nichia Chemicals in Tokushima when he contributed to the invention of blue LEDs.

The three will share a monetary prize of 8 million Swedish krona ($1.1 million).

Akasaki and Amano, pictured at right, managed to 'grow high-quality crystals of gallium nitride, a semiconductor for producing blue light—a process that had frustrated researchers' for decades, according to The New York Times. In fact, Akasaki first tried to create blue LEDs in the late 1960s but did not succeed until his efforts with Amano in 1986 produced 'high-quality crystals on a layer of sapphire coated with aluminum nitride,' the paper noted.

Nakamura, working independently at Nichia Chemicals, later made significant improvements to the other two Nobel prize recipients' methods for growing blue LED crystals. Also noted as the inventor of the efficient blue-light laser, Nakamura left Nichia in 1999 to take up a professorship at UC Santa Barbara. He sued the company over royalties for his inventions while employed at Nichia, eventually negotiating an $8.1 million settlement, according to the Times.