Is This for Real? ... UNIST and DGIST Research Teams Develop Ultra-High-Resolution Perovskite Display

A skin-attachable perovskite LED device that is very thin and can respond to various physical deformations.

[Asia Economy Yeongnam Reporting Headquarters, Reporter Hwang Du-yeol] A display technology that reproduces scenes as vivid as what the eye sees has been developed.

Professor Moon-ki Choi's team from the Department of Materials Science and Engineering at UNIST and Professor Ji-woong Yang's team from the Department of Energy Engineering at DGIST recently developed an ultra-high-resolution patterning technology through surface control of perovskite quantum dots.

This perovskite light-emitting device is known to have achieved the world's highest efficiency in all three primary colors: red, green, and blue.

The joint research team also produced a very thin "skin-attachable perovskite light-emitting device" using a new process, presenting a wearable display capable of adapting to various deformations.

As wearable electronic devices and Internet of Things (IoT) technologies advance, the demand for displays used in these devices is also increasing.

However, the existing patterning methods for making displays require complex processes, making them unsuitable for the less stable perovskite materials.

To address this, the joint research team developed a dry patterning technology based on a double layer of perovskite nanoparticles and organic semiconductors.

This new technology allows simple stamping-like patterning without the need for material etching or washing processes as in conventional methods, thus maintaining the stability of perovskite.

The research team drew ultra-high-resolution patterns with a line width of 400 nm and demonstrated excellent multicolor pixels through repeated processes (red, green, blue).

Example of ultra-high-resolution pixelation using a perovskite double-layer transfer printing method.

They also reported for the first time a high-resolution perovskite patterning of 2550 ppi (pixels per inch), which is four times the resolution of the latest smartphones.

Professor Ji-woong Yang of DGIST explained, “By introducing an organic semiconductor layer onto the perovskite surface in a simple way, we suppressed chemical and physical defects that could occur during the patterning process. The perovskite light-emitting layer formed by this technology reduced the spacing between perovskite nanoparticles and improved the interfacial properties with the hole transport layer.”

In fact, the device developed this time showed a much higher maximum external quantum efficiency (EQE) of 15.3% compared to existing devices.

The "skin-attachable perovskite LED device" is very thin and flexible, making it suitable for wearable devices.

The device size is 2.6 μm, about 1/40th the thickness of a human hair, and is formed inside an ultra-thin encapsulation structure, allowing it to adhere to various curved surfaces such as skin or leaves.

It not only withstands bending and twisting well but also has mechanical and optical stability to operate reliably even at a curvature radius of 0.25 mm, the thickness of a razor blade.

Professor Moon-ki Choi of UNIST said, “Since this research greatly increased the resolution of displays, it is expected to be widely applied in the development of future smart wearable devices. It will also contribute to enhancing immersion by implementing higher-resolution screens in virtual reality (VR) and augmented reality (AR).”

This research was published on October 27 in the world-renowned scientific journal Science Advances.

The research was supported by the National Research Foundation of Korea’s Excellent Young Researchers Program, Together Running Project, and Samsung Future Technology Development Center project.

(From left) Professor Moon-ki Choi of UNIST, Integrated MS-PhD student Jong-ik Kwon of UNIST, Integrated MS-PhD student Gyu-ri Park of DGIST, Professor Ji-woong Yang of DGIST.

This content was produced with the assistance of AI translation services.