Blue LED


Blue LED by MC

Every once in a while the Nobel Prize committee chooses to honor practitioners of applied physics for the physics Nobel. These are applications and products created using applied physics and which have the potential to profoundly impact the world in a constructive way. The career of Alfred Bernard Nobel, the Swedish chemist and engineer, for whom the prize is named was, in fact, a compelling example of what applied science can do. He invented the dynamite. He was an armaments manufacturer, which of course, is a powerful example of applied science even though its utility and moral grounding is dubious.

The 2014 Nobel Prize for Physics is an example of that. It has been shared by three professors, Isamu Akasaki, Hiroshi Amano and Shuji Nakamura for their invention of the blue Light Emitting Diode (LED) which has directly led to the creation of more energy efficient and therefore environmentally friendly white light. As has been pointed out when the blue LED is combined with the red and green LEDs they produce bright white light. It is used extensively around the world in many different ways, including in your smartphones. The spectral bluish white glow that you see when your smartphone is switched and during its active use, comes from the blue LED.

Physics can be as mind-numbingly esoteric as it can be miraculously useful. The beauty is that the esoteric is often directly connected to the useful. Speaking of the useful, I would like to quote from the Nobel Prize’s official press release:

“When Isamu Akasaki, Hiroshi Amano and Shuji Nakamura produced bright blue light beams from their semi-conductors in the early 1990s, they triggered a fundamental transformation of lighting technology. Red and green diodes had been around for a long time but without blue light, white lamps could not be created. 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. Akasaki worked together with Amano at the University of Nagoya, while Nakamura was employed at Nichia Chemicals, a small company in Tokushima. Their inventions were revolutionary. Incandescent light bulbs lit the 20th century; the 21st century will be lit by LED lamps.

White LED lamps emit a bright white light, are long-lasting and energy-efficient. 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.”

So here is to the three physicists.


About chutiumsulfate

South Asians can infer from my name what I am. View all posts by chutiumsulfate

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