Nobel Prize in Chemistry awarded for quantum dot technology

Stockholm:This year’s Nobel Prize in Chemistry was awarded to scientists who worked decades to make your TV watching experience better, among other things.

Moungi G. Bawendi, Louis E. Brus and Alexei I. Ekimov received the Nobel Prize in Chemistry for developing quantum dots, customizable nanoparticles which have different properties depending on their size.

 "Quantum dots have many fascinating and unusual properties. Importantly, they have different colors depending on their size," Chair of the Nobel Committee for Chemistry Johan Åqvist said.

You’re likely looking at light emitted from quantum dots right now, as many modern computer-monitors and televisions using QLED technologies use quantum dots to create RGB colors of each pixel.

But that’s not all. The quantum dot technology is used in biomedical research to visualize molecules. In the future, quantum dots could be used in new areas of quantum communications, flexible electronics, miniature sensors as well as in improving solar cell technologies.

What are Quantum Dots?
Quantum dots are very tiny semiconductors around 2-10 nanometers in size – a few billionths of a meter.

The size ratio of a quantum dot to a football is about the same as a football to planet Earth.

Quantum dots all have the same structure – a crystal of metal oxide atoms. Simply changing their size can completely alter their properties. Smaller dots emit blue light and larger dots red and yellow.

It’s not just their color that changes – but also their magnetic, electrical, thermal, catalytic properties. In other words, size matters.

Three Nobel Laureates
While the three chemists share the prize money worth 11 million Swedish crowns ($990,000, €948,000), they worked on quantum dots separately, and over several years.  

"Their incredible contributions to chemistry are reflected in their citation records: Bawendi shows an astonishing 100,000-plus citations in the Web of Science, and Brus 60,000-plus." David Pendlebury, Head of Research Analysis at the Institute for Scientific Information at Clarivate told DW.

The theory of quantum dots goes back over a hundred years, but scientists found it near impossible to produce these materials. They needed to be able to make perfect crystals where its structures needed to be precise down to the atomic level.

Nobel Prize winner Alexei Ekimov broke the deadlock and was the first to succeed in creating size-dependent quantum effects in glass. He did this by producing copper chlorine nanoparticles that displayed these quantum effects.

Luis Bruce observed the same effect for nanoparticles floating freely in a liquid solution.

For the dots to be useful, they need to be made with extreme control of size and surface. However, for a long time, no one thought these small particles could be produced.

Bawendi was awarded the Nobel Prize for doing exactly this – he invented the chemical method for creating quantum dots, allowing scientists to perfect the production of nanoparticles of very specific size and quality.

What’s more, the dots could be perfectly tuned to display different properties just by changing their size, and not their entire molecular structure.