Displays - Page 3

Canon has announced that it has developed perovskite quantum-dot inks for use in next-generation displays, with improved durability and potential for application in high-image-quality displays.

Quantum dots are semiconductor nanocrystals that measure only a few nanometers in diameter and can emit light with high brightness and high color purity. Displays with quantum-dot technology are attracting growing attention due to their wide color gamut that makes possible high visual expressiveness. Therefore, quantum dots for display is sought to achieve higher color purity and higher light utilization efficiency. In addition, though cadmium (Cd) has thus far been the preferred material for quantum dots, due to environmental concerns, there is a growing interest in Cd-free materials.

Researchers from Russia's Alferov University, ITMO University, Far Eastern Branch of Russian Academy of Sciences, Peter the Great St. Petersburg Polytechnic University, Skolkovo Institute of Science and Technology and China's Qingdao Innovation and Development Center have developed a novel design for a perovskite electrochemical cell for light-emission and light-detection, where the active layer consists of a composite material made of halide perovskite microcrystals, polymer support matrix, and added mobile ions.

Schematic diagrams of (a) the typical PeLED device structure, where CTL - charge transfer layer, QD - quantum dots and (b) the team's PeLEC device structure, where SWCNT - single-walled carbon nanotubes. Image from Opto-Electronic Advances.

The team explained that while halide perovskite light-emitting devices exhibit exceptional properties such as high efficiency, high color purity, and broad color gamut, their industrial integration generally suffers from the technological complexity of devices' multilayer structure alongside in-operation induced heating poor stability. Halide perovskite light-emitting electrochemical cells are a novel type of perovskite optoelectronic device that differs from the perovskite light-emitting diodes by a simple monolayered architecture. 

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 May 2023, 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.

Researchers from Korea's KIMM institute have fabricated full-color flexible microLED devices, using blue LEDs and perovskite quantum dot color conversion layers. The demonstrated device featured  1 mm pixel pitch LEDs (25.4 PPI) and could be bent with a radius of 5 mm without being damaged.

The researchers used a perovskite-QD and siloxane composite using ligand exchanged PQD with silane composite followed by surface activation by an addition of halide-anion containing salt. Due to this surface activation, the researchers say that it was possible to construct the PQD surface with a silane ligand using a non-polar organic solvent that does not damage the PQD. As a result, the ligand-exchanged PQD with a silane compound exhibited high dispersibility in the siloxane matrix and excellent atmospheric stability.

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.