Three quantum dot secrets that have kept us entertained for centuries

Three Quantum Dot Secrets That Have Kept Us Entertained for Centuries

Dec 16. 2016

Innovation in TV technology has introduced us to some of the most realistic picture quality available, as well as some of the most well-designed TVs to date.

Three quantum dot secrets that have kept us entertained for centuries

A mysterious technology that elevates the TV viewing experience has a fascinating history in the Middle Ages.

If you've ever walked into a cathedral and looked up to the shimmering stained glass windows casting a vibrant rainbow of lights on the congregation below, you'll appreciate why these beautiful pieces of art have been a key feature of churches since the Middle Ages.

But more than being aesthetical biblical depictions, scientists have discovered an intricate nanotechnology within the glass that dates back to the tenth century.

Nanotechnology within the glass that dates back to the tenth century

Medieval artists-cum-alchemists added gold and silver chloride to the molten glass to create spectacular tints of red and yellow. The chloride nanoparticles, it seems, were acting as quantum dots, reflecting red and yellow light, and the resulting light emittance has for centuries been awe-inspiring.

This mesmerising quantum dot nanotechnology played an integral role in those classic works of art — and continues to be a key component.

Mesmerizing quantum dot nanotechnology played an integral role in those classic works of art

Today, we continue to be entertained by coloured lights on a daily basis, albeit on a television screen at the temple called home.

Since the 1950s, when television sets became a common feature in our living rooms, the TV has had a litany of acronyms precede it including CRT, LCD, LED, HD, 3D, and now the vision for future displays: QD or Quantum Dot display.

From the first CRT TVs (cathode ray tube), viewers in the 1950s saw the world exclusively in black and white, although research into colour transmission was already underway. LCD TV took over from CRT and was popular in the early 2000s, giving way to LED TV (liquid crystal display) in 2009, which significantly improved picture quality by illuminating the screen on the back with light emitting diodes.

Each acronym represents the efforts of technologists working to make what appears on your TV screen as bright and true to life as possible.

1. The era of quantum dot was ushered in by scientists

Up to 10 centuries after our unwitting Gothic alchemists, quantum dots were officially discovered by Russian physicist Alexei Ekimov in 1980 and American chemist Louis E. Brus in 1982.

The two scientists found that breaking a material with semiconductor properties into nano-sized particles, particles that are slightly bigger than water molecules, brings out an entirely new property within the material.

They discovered the colour of the light emitted by each particle varied according to their sizes, making them capable of replicating all of the colours in the prism range. What caused this phenomenon was the change in the band gap energy, one of the most important properties of a semiconductor.

This means, if the size of a quantum dot can be minutely adjusted, quantum dots can be used to create all the colours of the rainbow, perfectly.

Dr. Paul Alivisatos, Professor of Nanoscience and Nanotechnology at the University of California, Berkeley, had a stroke of genius while studying the development of our eyes. He realized that for a really high quality display, the light emission from the display needs to match the receptors in our eyes.

And that's exactly what Dr. Alivisatos did. By studying materials just nanometers—billionths of a meter—in diameter, his lab perfected the science of producing the same nanosized crystals, known as quantum dots, that medieval artists unwittingly had, ten centuries prior. And as we already saw, when quantum dots come into contact with light, they convert that energy into nearly every colour on the visible spectrum. "The quantum dots in the SUHD display match the colour of our eye very precisely and therefore it can show very realistic colours, more realistic and more like real life than what we normally see in a display," said Dr. Alivisatos.

2. Quantum dots are one tiny material making a HUGE impact

Unsurprisingly, TVs were the very first electronic device to apply quantum dot technology.
Aside from showing colours more accurately, quantum dots expand the colour palette that TVs can display with better efficiency, allowing you to enhance the brightness on your TV without draining energy.

By showcasing a hidden colour palette that previous TVs could not, the colours of your favourite football team's kit will really stand out on the field of green.

It is this higher capacity to express true to life colours while maintaining durability that gives quantum dot technology an edge over OLED TV, once touted to be the future of TVs.

In addition, quantum dots are inorganic materials—just like rocks and diamonds—and are more stable with a longer lifespan compared to OLED, which is composed of organic materials. Quantum dots also tout another huge benefit: lower production cost.

"With longer lifespan and lower production costs in comparison to OLED TVs, the effect these tiny crystals will have on the industry is massive," says Jason Hartlove, CEO of Nanosys, one of the biggest quantum dot technology companies that currently partner with Samsung.

3. Quantum dots are an ever-evolving technology

"Quantum dot technology is showing rapid development," says President Hyun-suk Kim of Samsung Electronics Visual Display Division. "This technology is continuously advancing and I can confidently say it really is progressing faster than our expectation."

Samsung Electronics is in the lead of commercialising quantum dot technology, recently making it cadmium free. Cadmium is a toxic material to the human body, as well as to the environment. Samsung introduced the first cadmium-free quantum dot TV—the SUHD TV—in 2015.

"Looking back on the history of materials development, display materials have a distinct gap between actual development to device production," says Hyuk Chang, materials expert and Executive Vice President of Samsung's Advanced Institute of Technology.

LCD was first commercialised in TVs in 1968, marking 80 years from the first discovery of liquid crystal in 1888. The first OLED TVs were launched in 2007, marking half a century after identifying electroluminescence in organic materials in the early 1950s. Quantum dot, on the contrary, took only around thirty years. "It's an amazing accomplishment in a short amount of time," said Chang, "and there are still many areas with the potential of utilizing quantum dot we aren't even aware of yet."

Quantum dot technology holding infinite possibilities

Clearly, quantum dot technology holds infinite possibilities. Not only can it be used for rollable and foldable displays, but sensors, bio imaging, and even artistic works like paintings. And just like centuries-old stained glass windows, quantum dot technology will be capturing our attention for a very long time.

This article was first published as an advertisement feature on bbc.com and was created by BBC StoryWorks, BBC Advertising's commercial content team, on behalf of Samsung Electronics.