American and 2 Japanese Physicists Share Nobel for Work on LED Lights
The
2014 physics award went to Isamu Akasaki and Hiroshi Amano of Japan
and Shuji Nakamura of the University of California, Santa Barbara,
for “the invention of efficient blue light-emitting diodes, which
has enabled bright and energy-saving white light sources.”
The
three scientists, working together and separately, found a way to
produce blue light beams from semiconductors in the early 1990s.
Others had produced red and green diodes, but without blue diodes,
white light could not be produced, the Royal Swedish Academy of
Sciences said on Tuesday morning in its prize citation.
They
succeeded where everyone else had failed,” the academy said.
Their
work has spurred the creation of a whole new industry. The committee
that chose the winners said light-emitting diodes, or LEDs, would be
the lighting source of the 21st century, just as the incandescent
bulb illuminated the 20th.
Dr.
Akasaki, 85, of Meijo University and Nagoya University, and Dr.
Amano, 54, of Nagoya University, are Japanese. Dr. Nakamura, 60, is
American. Awakened by a phone call from the Swedish academy, he
described it in a news conference as “unbelievable.”
In
its announcement, the academy recalled Alfred Nobel’s desire that
his prize be awarded for something that benefited humankind, noting
that one-fourth of the world’s electrical energy consumption goes
to producing light. This, it said, was a prize more for invention
than for discovery.
Frances
Saunders, president of the Institute of Physics, a worldwide
scientific organization based in London, agreed with those
sentiments. Noting in an email statement that 2015 is the
International Year of Light, she said, “This is physics research
that is having a direct impact on the grandest of scales, helping
protect our environment, as well as turning up in our everyday
electronic gadgets.”
In
Africa, millions of diode lamps that run on solar power have been
handed out to replace polluting kerosene lamps.
For
the same amount of energy consumption, LED bulbs produce four times
the light of a fluorescent bulb and nearly 20 times the light of an
incandescent bulb
LED
bulbs are also more durable, lasting 10 times as long as a
fluorescent bulb and 100 times as long as an incandescent bulb.
Light-emitting
diodes are already ubiquitous — in pockets and purses, in
smartphones, as well as in televisions, lasers and optical storage
devices.
And
their future is vaster still. “The LED lamp holds great promise for
increasing the quality of life for over 1.5 billion people around the
world who lack access to electricity grids,” the Nobel committee
said. “Due to low power requirements, it can be powered by cheap
local solar power.”
The
work rewarded on Tuesday was the latest step in an evolution that
began with Thomas Edison’s burning out light-bulb candidates in his
Menlo Park laboratory in the late 19th century.
Incandescent
bulbs use electricity to produce heat in a glowing filament that
emits a comparatively small amount of light; fluorescent lights use a
gas.
Light-emitting
diodes are based on the same quantum magic that gave birth to
computers, smartphones, transistor radios and all other electronic
devices.
The
diodes are no bigger than a grain of sand and consist of sandwiches
of semiconducting materials. When an electric field is applied,
negative and positive charges meet in the middle layer and combine to
produce photons of light. The color of the light produced depends on
the type of semiconductor.
Nick
Holonyak Jr. of the University of Illinois, who invented the first
red-light diode in 1962, has
called the LED the “ultimate lamp” because
“the current itself is the light.”
Red-
and green-emitting diodes have been around for a long time, but
nobody knew how to make a blue one, which was needed for blending
with the others to create white light. The amount of information that
can be packed into a light wave increases as its wavelength shortens,
making blue the color of choice for conveying information.
That
is where the new laureates, working independently, came in. The key
was to grow high-quality crystals of gallium nitride, a semiconductor
for producing blue light — a process that had frustrated
researchers.
Dr.
Akasaki first tried to grow the crystals in the late 1960s as a young
research associate at Matsushita Research Institute in Tokyo. It was
not until 1986 that he and Dr. Amano, who was then his graduate
student, succeeded in growing high-quality crystals on a layer of
sapphire coated with aluminum nitride, and found out their properties
were enhanced when they were scanned with an electron beam.
The
royalties from their work subsequently funded the construction of a
whole new research institute, the Nagoya
University Akasaki Institute.
Dr.
Nakamura, then at the Nichia Corporation, a chemical engineering and
manufacturing company, succeeded in growing his own crystals,
improving on the other two scientists’ method. In 2006 he was
awarded the Millennium Technology Prize of one million euros (about
$1.3 million) for inventing the first efficient blue-light laser,
opening the way for things like Blu-ray players.
Dr.
Nakamura left Nichia in 1999 to join the University of California,
Santa Barbara. Two years later, in a shocking challenge to Japanese
traditions of subservience, he sued the company for 20 billion yen,
$193 million at the time, saying he deserved a share of royalties for
his inventions. Nichia had given him an award of 20,000 yen — about
$200 — for his contributions to the company.
A
court awarded him the full amount, but the company appealed. In 2005
he and the company settled for a payment of 843 million yen, or about
$8.1 million.
As
is often the case with Nobel Prizes, not everybody was happy on
Tuesday. The prize can be awarded to no more than three people, and
Dr. Holonyak expressed dismay that various American scientists who
had laid the framework were left out.
“We’re
always tugging and pulling,” he said in a telephone interview from
Illinois. “Nobody is smart enough to know all this.”
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