South Korean researchers have developed the world’s highest-performing stretchable displays using quantum dots. These displays maintain functionality even when stretched by as much as 150%, signaling the advent of innovative electronic devices previously unseen.
The research team led by Hyeon Taeg-hwan, Director of the Institute for Basic Science (IBS) Center for Nanoparticle Research, and Kim Dae-hyeong, Vice Director, announced on April 16 the creation of quantum dot light-emitting diode (QLED) displays. These displays exhibit no loss in image quality even when stretched like rubber.
Recently, there has been an increase in displays that can operate even when folded or rolled. Development is also underway for stretchable displays that can be pulled from both sides, but so far, only the wiring, not the light-emitting parts, could be stretched. This method results in a decreased area ratio of the light-emitting parts when stretched, leading to low brightness, poor luminous performance, and reduced durability due to friction between the light-emitting and wiring parts.
To solve the problem of image degradation, a device that can stretch both the wiring and the light-emitting layer needs to be developed. Current efforts using organic electronic composite materials continue. However, these are criticized for their poor color reproduction and are expected to fail to reach commercialization levels.
The IBS research team has addressed these issues using quantum dots as the light-emitting material. They developed a technique to mix red, green, and blue quantum dot devices with an elastic polymer. The resulting solution was used to create a light-emitting layer 40 nanometers thick.
The stretchable display developed in this project showed outstanding performance, with a brightness of 10,170 nits and an operating voltage of 6.2V, the best for a stretchable quantum dot light-emitting device. Its performance significantly surpasses that of devices developed by Stanford University researchers in 2022, which reached 7,450 nits at 15V.
Professor Kim Dong-chan from Gachon University, a participant in the research, said, “We have also developed a new high-resolution patterning technology that can be applied to the stretchable quantum dot emitting layer. By combining the emitting material with the patterning technology, we have completed a full-color stretchable QLED device.”
A significant advantage is the lack of performance degradation even when the shape changes. Even when stretched laterally by 1.5 times, the distance between the quantum dots inside the device almost does not change. This means that a 20-inch QLED TV can be stretched to 30 inches without affecting the image quality.
Vice Director Kim said, “Shape-adaptable displays using stretchable components are a key trend for the next generation of display technology. They can be used in places that are difficult to achieve with flexible or foldable form factors, such as the curved interiors of cars, potentially accelerating the era of free-form displays.”
The results of this research were featured in the international scientific journal Nature Electronics on April 15.
Reference
Nature Electronics, DOI: https://doi.org/10.1038/s41928-024-01152-w
