Displays

On March 27 the MicroLED Industry Association will host a private webinar on perovskite materials for the microLED industry. Perovskite materials hold great promise for the solar industry and in recent years we are seeing promising signs for the adoption of perovskites the display industry.

The upcoming Seminar will feature four world-leading speakers, and will also be open to a Q&A session. We will learn more about the state-of-the-art perovskite research and development, with a focus of course on applications in the microLED industry - for both perovskite QDs and PeLEDs.

Researchers from The University of Tokyo and Yamagata University have addressed the difficulty in creating blue quantum dots by developing a unique self-organizing approach for producing lead bromide perovskite quantum dots. The research also incorporates cutting-edge imaging technology to characterize these novel blue quantum dots.

Quantum dots (QDs) are used in optoelectronic devices and quantum computing, among other things, and are referred to as "artificial atoms" due to their confined and distinct electronic properties. Quantum dots have characteristics that fall in between those of bulk semiconductors and individual atoms and molecules. Their photoelectric qualities vary depending on their size and shape. Quantum dots (QDs) are considered attractive materials for the emissive constituent of light-emitting diodes (LEDs) due to their high color intensity in a small spectral region, facile color tunability, and notable stability. Moreover, QD-based materials exhibit refined colors, longer lifetimes, reduced production costs, and lower energy requirements compared to typical luminescent materials used in organic light-emitting diodes (OLEDs).

Researchers from Korea's PEROLED, Seoul National University and Korea Basic Science Institute (KBSI), along with scientists from the UK's University of Cambridge, have reported an ultra-bright, efficient and stable perovskite LED made of core/shell perovskite nanocrystals with a size of approximately 10 nm, obtained using a simple in situ reaction of benzylphosphonic acid (BPA) additive with three-dimensional (3D) polycrystalline perovskite films, without separate synthesis processes.

During the reaction, large 3D crystals are split into nanocrystals and the BPA surrounds the nanocrystals, achieving strong carrier confinement. The BPA shell passivates the undercoordinated lead atoms by forming covalent bonds, and thereby greatly reduces the trap density while maintaining good charge-transport properties for the 3D perovskites.

Researchers from the University of Tokyo have made progress with the development of blue-emitting quantum dots, which is seen as highly challenging. They have shown that using a new bottom-up design strategy and self-organizing chemistry can help create a high purity blue-emitting QD material (with a narrow emission spectrum).

The newly developed QDs have a special chemical composition that combines both organic and inorganic substances, such as lead perovskite, malic acid, and oleylamine. The materials self-aligned into a cube of 64 lead atoms. The lead researcher, Professor Eiichi Nakamura, says that "it took over a year of methodically trying different things to find that malic acid was a key piece of our chemical puzzle".

Researchers from the Ulsan National Institute of Science and Technology (UNIST) have teamed up with researchers from Daegu Gyeongbuk Institute of Science and Technology (DGIST) to develop a patterning technique for the production of perovskite nanocrystal displays which are ultra-thin and high-resolution. The production involves a very simple stamp-like printing process that will facilitate the commercialization of the new technique.

Double-layer transfer printing process with RGB pixelated arrays of PeNCs. Image from Science Advances

The technique reportedly enabled the team to produce a display with RGB pixel patterns of 2,550 pixels per inch, which is about 400 percent higher resolution than the latest high-end smartphones.

Perovskite-Info is proud to announce an update to our Perovskite for the Display Industry Market Report. This market report, brought to you by the world's leading perovskite and OLED industry experts, is a comprehensive guide to next-generation perovskite-based solutions for the display industry that enable efficient, low cost and high-quality display devices. The report is now updated to September 2022, with all the latest commercial and research activity.

Reading this report, you'll learn all about:

• Perovskite materials and their properties
• Perovskite applications in the display industry
• Perovskite QDs for color conversion
• Prominent perovskite display related research activities

The report also provides a list of perovskite display companies, datasheets and brochures of pQD film solutions, an introduction to perovskite materials and processes, an introduction to emerging display technologies and more.

A Florida State University research team, led by FSU Professor of Chemistry Biwu Ma, has developed a simple and effective approach to create an efficient and stable blue light from metal halide perovskites.

Scientists have already created highly efficient and stable perovskite-based LEDs for green and red light, but an efficient and stable blue light has been difficult to achieve. Blue light requires a lot of power, and the blue color purity often decreases over time. An efficient and stable blue light is crucial for creating white light.

Researchers from the Beijing Institute of Technology and MIIT Key Laboratory for Low Dimensional Quantum Structure and Devices have developed perovskite quantum dots microarrays with strong potential for quantum dots color conversion (QDCC) applications, including photonics integration, micro-LEDs, and near-field displays.

QDCC is considered a versatile way to achieve full-color organic light-emitting diodes and micro-light-emitting diodes displays. QDCC provides a wide range of color performance and easy integration. However, conventional QDCC pixels, fabricated by the commonly used method of inkjet printing, tend to be too thin to achieve efficient color conversion. The conventional combination of quantum dots and coffee-ring effects or puddle of particle-laden liquid that occur after evaporation, lowers the light conversion efficiency and emission uniformity in quantum dot microarrays. This also contributes to blue-light leakage or optical crosstalk, where unwanted coupling occurs between signal paths. 

Researchers from Korea's Sungkyunkwan University and Gyeongsang National University have developed an innovative technique to develop transparent displays with high resolution and flexibility using perovskite materials.

Solution-based perovskites have been attracting attention in the area of display technology for many years, due to their exceptional optical-based electronic characteristics and ease of preparation. Owing to the benefits of solution-based perovskites, researchers have long envisioned the commercial adoption and implementation of flexible transparent displays.

This article was extracted from the Perovskite for Displays market report.

Given perovskites materials' unique optical properties, these materials are being intensively researched for both photovoltaic and display applications (as well as several others). In this article we will take a look into the possible application areas in the display industry that can benefit from perovskite materials.

Perovskite QDs

Perovskite-based QDs (PerQDs) are considered a viable Cd-free alternative for display applications, with high PL quantum yields, wide wavelength tunability and ultra-narrow band emission. The main advantages of PerQDs are:

• Low cost
• High performance
• RoHS compliance (despite the lead content)