Trio wins chemistry Nobel for work on quantum dots

Moungi Bawendi, Louis Brus and Alexei Ekimov were honoured for their work on the tiny particles

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Three scientists in the US won the Nobel Prize in chemistry on Wednesday for their work on quantum dots particles just a few atoms in diameter that can release very bright coloured light and whose applications in everyday life include electronics and medical imaging.

Moungi Bawendi, of MIT; Louis Brus, of Columbia University; and Alexei Ekimov, of Nanocrystals Technology Inc., were honoured for their work with the tiny particles that "have unique properties and now spread their light from television screens and LED lamps, according to the Royal Swedish Academy of Sciences, which announced the award in Stockholm.

"Why does it matter, right, that we can make tiny particles that nobody can see, but they have colours?" Pernilla Witting Stafshede, a member of Nobel committee that awarded the prize. "This is actually used today both in medicine and technology. ... We have displays on TVs, in your cellphone, that use quantum dots inside to make just brighter colours." The suspense surrounding the academy's decision took an unusual turn when Swedish media reported the names of the winners several hours before the prize was announced. The advance notice apparently came from a news release sent out early by mistake.

Quantum dots' electrons have constrained movement, which affects how they absorb and release visible light, allowing for very bright colours.

The dots are nanoparticles that glow blue, red or green when illuminated or exposed to light. The colour they emit depends on the size of the particles. Larger dots shine red, and smaller dots shine blue. The colour change is due to how electrons act in more or less confined spaces.

While physicists had predicted these colour-change properties as early as the 1930s, creating quantum dots of specific controlled sizes was not possible in the lab for another five decades.