Pusan National University and Sungkyunkwan University Develop Ultra-Precise Quantum Dot Alignment Technology Without Damage

Non-Destructive Photolithography Without PR or Ligand Exchange... A Breakthrough for Ultra-High-Resolution Displays for AR and VR

A joint research team from Pusan National University and Sungkyunkwan University has developed a new manufacturing technology that can arrange quantum dots, a next-generation display material, in an ultra-precise manner without damage. The technology is evaluated as a solution to the quantum dot patterning problem, which has been considered a key challenge in realizing ultra-high-resolution, high-reliability microdisplays for AR and VR.

On February 4, a research team led by Professor Noh Jeonggyun of the School of Electrical and Computer Engineering and Professor Hwang Dohun of the Department of Chemistry at Pusan National University announced that, through joint research with a team led by Professor Lim Jaehun of the Department of Energy Science at Sungkyunkwan University, they have developed a non-destructive photolithography technology that can precisely micro-pattern quantum dots without using a photoresist (PR) or a ligand-exchange process.

Quantum dot light-emitting diodes (QD-LEDs) have attracted attention as next-generation display devices thanks to their high color purity and compatibility with solution processing. However, commercialization has been hampered by limitations in patterning technologies capable of implementing RGB pixels at ultra-high resolution. Conventional inkjet printing has constraints in achieving high resolution, and photolithography-based processes have suffered from problems such as quantum dot damage and the need for complex ligand-exchange steps.

To overcome these limitations, the research team developed a "blend-type emissive layer (b-EML)-based high-resolution patterning technology" that can precisely arrange quantum dots without damaging them and without PR or ligand exchange. When quantum dots are blended with a hole-transport polymer (PVK) and a photo-crosslinker (FPA) and then irradiated with ultraviolet light, only the polymer selectively cures to form a three-dimensional network structure, within which the quantum dots are stably fixed.

Using this technology, the team achieved ultra-high-resolution quantum dot patterns of 10,000 ppi for monochrome and more than 1,000 ppi for RGB full color, while significantly improving pattern fidelity and emission characteristics compared with existing methods. QD-LED devices fabricated using this process showed a 1.7-fold increase in external quantum efficiency and more than a threefold improvement in operational lifetime.

This technology is highly significant in that it simultaneously resolves the trade-off between material damage and device performance degradation during QD patterning. It can also be applied to a wide range of nanocrystal materials, including cadmium-free InP-based quantum dots and silver nanoparticles, and is therefore expected to see broad use across next-generation displays and optoelectronic devices.

Professor Noh Jeonggyun of Pusan National University said, "This is a universal technology that can simplify the process while minimizing damage to quantum dots," adding, "It will help accelerate the commercialization of ultra-high-resolution quantum dot displays for AR and VR."

The research results were published in the February issue of Advanced Functional Materials, an international journal in the field of materials science, and were selected as the cover paper in recognition of the creativity and completeness of the work.

Noh Jeonggyun and Hwang Dohun, professors at Pusan National University; Lim Jaehoon, professor at Sungkyunkwan University; Lee Jaeyeop and Kwak Seoni, doctoral students at Pusan National University (from left).

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