Quantum dot displays could arrive on smartphones within three years

Scientists have developed a method for manufacturing quantum dot displays that could see small products such as mobile phones using the technology within three years.

Researchers have been attempting to utilise quantum dot technology in displays for around a decade now, but so far have been unable to produce a viable product that could be brought to market.

Quantum dots, essentially semiconducting crystals measuring billionths of a metre across, are potentially able to produce images much crisper than is possible by the current crop of LCD displays, emitting light at an extremely narrow and tunable range of wavelengths.

Now scientists have shown, in research published in Nature, that the secret to easily manufacturing the displays has been found in the age-old technique of ink stamping, used to print text and pictures since the likes of William Caxton.

In the past it has been considered very difficult to produce effective quantum displays as the technique used, involving spraying the dots onto a material in a manner akin to an ink-jet printer, which would result in low quality displays. That was due to the negative effects of an organic solvent that prepares the dots.

Byoung Lyong Choi, an electronic engineer at the Samsung Advanced Institute of Technology in Korea, has found that by using a patterned silicon wafer as an ink stamp to then pick up strips of dots made from cadmium selenide, before pressing them onto a glass substrate to create red, green and blue pixels, they were able to remove the necessity for a solvent.

While this more traditional approach may sound simple, achieving it at a quantum level was rather tricky.

“It took us three years to get the details right, such as changing the speed and the pressure of the stamp to get a 100 percent transfer.”

Choi and his team have been able to produce a 10cm full colour display, with brighter pixels than rival methods have achieved.

“The maximum brightness of the red pixels is about 50 percent better,” Choi said.

The technique also allows highly efficient conversion of electrical power to light, with maximum power efficiency for red pixels 70 percent better.

The scientists were also able to bend the screen without effecting the performance, meaning that the technology, which is expected to be cheap to produce and hardwearing, could have a range of applications in the future other than just high quality large screen TV sets.

Small scale devices could be commercialised within a few years.

“I can imagine that we will have small cell-phone displays using this technology within around three years,” said Seth Coe-Sullivan of QD Vision, a company that produces devices with lighting based on Quantum dots.

“For the rest, there may be more of a wait.”