Technical / Research - Page 4

Researchers from Korea's KAIST, ETRI, and Dong-A University propose a new stretchable OLED display architecture, based on a 3D form that includes hidden sections that act both as active emitting areas and interconnectors. The idea is that as the OLED display is stretched, these areas pop into place and add to the emitting area of the OLED. The areas are basically hidden pixels that are only used when the display stretches.

To create this OLED device, the researchers attached ultrathin OLED films to a 3D rigid island array structure through quadaxial stretching, enabling precise, deformation-free alignment. The researchers explain that a portion of the ultrathin OLED is concealed by letting it ‘fold in’ between the adjacent islands in the initial, non-stretched condition and gradually surfaces to the top upon stretching. 

Researchers from the University of Manchester, University of Cambridge and University of Eastern Finland, led by Dr. Alexander Romanov have developed a new deep-blue Carbene-Metal-Amide (CMA) OLED emitter material with promising operating lifetime.

The emitter is based on a a new CMA complex with a rigid amide donor, benzoguanidine. The researcher say that the new design unlocks bright charge-transfer deep-blue emission with 100% photoluminescence quantum yields. The excited state lifetimes of the new CMA complexes are among the lowest reported to date among all TADF emitters
(down to 213 ns), resulting in remarkably fast radiative rates of up to 4.7 × 10 6 s⁻¹ . 

Researchers from Chung-Ang University developed a new AI model to predict the characteristics of blue OLED devices. The new model is highly accurate - and achieved a prediction accuracy of 99.2% for the triplet fusion rate constant and 99.9% for the triplet emission rate.

To develop this model, the researchers first developed modeling that improved the calculation accuracy of the triplet emission ratio, one of the key properties of blue light emitting materials. Based on this modeling, an AI model was created to predict the triplet emission ratio and fusion rate constant by generating a transient EL extinction curve.

Researchers from the University of Science and Technology of China (USTC), in collaboration with scientists from the University of Cambridge and Beijing Information Science and Technology University developed a novel blue OLED emitter design, based on 5Cz-BO molecules, that offers highly efficient emission with a narrow emission spectrum.

The new OLED emitters incorporate multiple carbazole donor groups into the multiple resonance (MR) type electron acceptor units. This design offers narrow-band short-range charge transfer excited states and it also reduced the energy level difference between the molecule’s singlet and triplet states.

LG Display developed a new OLED microdisplay (OLEDoS) that achieves a brightness of 10,000 nits. This development is presented at SID DisplayWeek 2024. 

To achieve this high brightness, LG Display's research team used newly-developed high performance OLED materials, and also used a micro lens array (MLA) to expand the light output from the device. 

Researchers from the Universities of St Andrews, Kyoto and Kyushu have coincidentally developed state-of-the-art multi-resonant TADF (MR-TADF) OLED emitters, based on a helical boron-nitrogen-oxygen doped nanographene design.

In these multiple studies, the researchers have shown that it is possible to obtain deep blue, narrowband emission, very fast reverse intersystem crossing rates constants, and high-efficiency vacuum-deposited OLEDs.

Researchers from the Fraunhofer IPMS have developed a semi-transparent high resolution OLED microdisplay, that is significantly lighter than conventional combiner-based optical see-through near-to-eye systems. The specification of the display was not disclosed, but one can see it's a monochrome yellow panel.

The Fraunhofer researchers developed a new semi-transparent OLED-on-silicon microdisplay technology, which enabled the new display. The technology is based on modern and advanced silicon CMOS processes, applied to silicon-on-insulator (SOI) wafers. The new wafer technology can be used to implement very thin circuitry layers. With the help of a specific IC design and an appropriate transfer-to-glass process flow, the transparent OLEDs were enabled.

MicroLED Connect, our hybrid event series focusing on the microLED industry, will be hosting a two-day virtual event focused on the OLED innovations, technologies, manufacturing, markets and more. The online event will take place next week, on April 10-11, and will be an excellent opportunity to learn the latest OLED updates and connect with industry professionals on our excellent online event platform.

Today we have published the agenda for this event, with 20 exciting talks by leading OLED developers, supply chain companies and top-edge researchers. This will be an excellent opportunity to learn and connect with the OLED industry. You can register for the event here, with a yearly pass to MicroLED-Connect (with an option to also include entry into our September on-site event in Eindhoven, The Netherlands). Our members also gain access to past event recordings.

Researchers from the University of St. Andrews in the UK, led by Professor Ifor Samuel and Professor Eli Zysman-Colman, identified the key processes controlling the efficiency of TADF OLED emitters under high brightness. This could assist material develops on their quest to design materials that maintain high efficiency at high brightness.

The researchers explain that OLEDs have lower efficiency at higher brightness, and in many TADF materials, the efficiency roll-off is severe, so that the high efficiencies achieved at very low brightness are not maintained at higher brightnesses needed for displays or lighting applications. For the first time, the researcher identified the key processes controlling the triplet population, and propose a figure of merit for efficiency roll-off.  

Xiaomi announced a strategic partnership with Lumilan, an OLED materials developer. Lumilan, with support from Xiaomi, built a new R&D lab in Ningbo, China, to develop new materials targeting smartphone display applications.

Xiaomi aims to get early access (or perhaps exclusive access) to novel OLED material to enhance its competitiveness. It is likely that the two companies aim to develop new OLED stack materials and perhaps new OLED emitters (Lumilan already develops TADF emitters).