Researchers from the Beijing Institute of Technology together with colleagues from the Beihang University have developed a new method to fabricate color-converted QL-ED panels using photolithographic fabrication.

The panels are based on emissive QDs, at a resolution of up to 6350 PPI (the researchers fabricated a range of panels, using pixel sizes ranging from 20 x 20 micron down to 2x2 micron). The patterned blue devices achieve a peak EQE of 7.8% and a maximum brightness of almost 40,000 nits. The patterned red devices achieve a peak EQE of 18% and a maximum brightness of just over 100,000 nits.

This is a sponsored post by QNA Technology

Cost and performance could make QDEL technology a real competitor to OLED. A potential scenario? Notebooks will adopt it first, followed by TVs and perhaps smartphones. Implementing this technology is relatively straightforward, provided blue quantum dots help the industry achieve its desired lifespan goals. This is an opportunity for Europe, which has blue quantum dots know-how and product at home (QNA Technology, Poland).

Low-Cost Production, High Performance

Quantum-Dot Electroluminescence (QDEL) represents a major evolution in emissive display technology, relying on electrically stimulated quantum dots (QDs) rather than photoluminescent down-conversion. QDEL’s core advantage lies in its solution-processed manufacturing—using coating, lithography, etching (C+L+E), or inkjet printing (IJP)—instead of vacuum thermal evaporation (VTE), which dominates OLED fabrication. 

Quantum dots developer QustomDot, a spin-off from Ghent University, announced the commercial availability of its second-generation QustomJet Red ink that makes high-efficiency color conversion a viable pathway for microLED cost reduction.

The company says that its new cadmium-free, solvent-free inkjet ink is specifically designed for quantum dot color conversion (QDCC) applications and delivers multiple competitive advantages for display manufacturers: excellent optical specs, enhanced printability with standard industrial inkjet systems, superior shelf life stability, and exceptional reliability under high-intensity blue light exposure, addressing the key challenges that have limited widespread adoption of quantum dot color conversion.

Researchers from Korea's Daegu Gyeongbuk Institute of Science and Technology (DGIST) developed a stretchable QD color conversion layer, that can be used in stretchable microLED displays. These QD films use a technology developed at DGIST that enables the direct linkage of quantum dots.

The researchers say that the color-conversion layer delivers high color reproducibility while maintaining performance even when stretched by more than 50%.  The color-conversion layer fabricated with this technology achieved a high resolution of 313 PPI.

Researchers from Korea's Daegu Gyeongbuk Institute of Science and Technology (DGIST) developed a new way to pattern QDs, using direct optical lithography (DOL). DOL can be used to pattern QDs with ultra-high resolutions - without any photoresist.

In addition to developing this method, the researchers provided guidelines for selecting cross-linkers essential for fabricating high-performance QLEDs. 

Researchers from North Carolina State University developed multi-robot self-driving laboratory that autonomously discovers high-performance quantum dots. The "Rainbow Lab" can conduct and analyze up to 1,000 experiments per day without human intervention, dramatically accelerating the pace of materials discovery.

The researchers say that the robots automatically prepare chemical precursors, mix them, and execute multiple reactions in parallel using miniaturized batch reactors – up to 96 reactions at a time. The system then automatically transfers all reaction products to a characterization robot, which analyzes the outcomes. From start to finish, every step is fully automated and intelligently coordinated.

According to a report from Korea, Samsung Display acquired a portfolio of 53 patents related that quantum dot technology from Merck.

The company plans to use these patents to enhance its own QD display technologies - used in their QLED TVs (QD-Backlit LCDs) and QD-OLED TVs - and in the future its QD-EL emissive displays. These patents will also help Samsung in its competition with China-based display makers.

Researchers at China's Ningbo University have introduced two key molecular additives into CsPbBr₃ perovskite quantum dots (PeQD) inks: an organic pseudohalide, dodecyl dimethylthioacetamide (DDASCN), and a photosensitive ligand, pentaerythritol tetrakis(3-mercaptopropionate) (PTMP).

With this synergistic strategy, the team fabricated fully solution-processed green perovskite QLEDs that achieved a maximum luminance of 30,500 cd/m² and an external quantum efficiency of 18.6%, ranking among the highest reported for solution-processed perovskite QLEDs.

According to a report from Korea, Samsung has teamed up with its QD supplier Hansol Chemical to simplify the structure of its QD films. The company aims to introduce new lower-cost QD-LCD films.

The report suggests that Samsung developed a technology to encapsulate individual QD particles, and so the new films could be produced without the encapsulation (barrier) films. This will result in a simple structure of only three layers - two PET layers and the QD layer between them. 

Quantum Dots technology is being used today in display applications such as LCDs, OLEDs and MicroLEDs. It is expected that adoption QDs in the display industry will continue to grow in the future. Here are some recent and popular news that you may find of interest:

• Samsung aims to commercialize QD-EL displays in the next few years, to accelerate its R&D
• SDC shows a cadmium-free QD-EL display prototype with a brightness of 400 nits
• Sharp demonstrates 12-inch and 30-inch QD-EL display prototypes
• The QD materials market to reach $100 million in 2024 and $122 by 2027
• TCL CSoT shows a 14" inkjet printed QD-EL display
• TCL launches the world's largest miniLED QLED TV at 115-inch
• Samsung developed a technology to recover and refine QD-OLED inks
• The 2023 Nobel Prize in Chemistry awarded for the discovery of quantum dots
• Apple adopts red QD films for the first time in its latest M4 MacBook Pro laptops
• IDTechEx: The global QD market will reach $550 million by 2034
• Shoei Chemical acquires leading QD developer Nanosys
• Canon announces new quantom-dot inks for display applications
• Samsung developed an all-printed 12.4" 182 PPI EL-QD display
• Newly-developed perovskite QDs are promising for display color conversion applications