Technical / Research - Page 7

Universal Display Corporation announced that it has acquired Merck's Phosphorescent OLED Emitter Intellectual Property (IP) assets. This portfolio includes over 550 issued and pending patents around 172 patent families with an average lifetime of 10 years, and represents over 15 years of R&D. 

The two companies also entered into a multi-year collaboration agreement, in which the two companies will create advanced PHOLED stacks based on UDC's OLED green and yellow emitters and Merck's transport and host materials.

Researchers from Carnegie Mellon University's Future Interfaces Group (FIG) designed a new haptic screen technology, which they call Flat Panel Haptics, that uses embedded electroosmotic pumps (EEOPs) that can move liquids quickly using electrical fields. 

The whole haptic layer is thin (just 1.5 mm thick) and can be placed behind a flexible OLED display to create an useful haptic display, as can be seen in the video above - buttons or keys can pop-up from the screen, and the interface can take advantage of shaped icons (like a play button or a stop button). Currently the shapes are pre-defined and cannot be altered by the user, but in the future this may change if the FPH technology is used to create small dot-matrix items.

Researchers from Australia's University of New South Wales (UNSW) have shown that OLED devices can be used to detect and map magnetic fields using magnetic resonance. The OLED is used to create a simple device, that does not need lasers like other methods used today.

This is still early research, but it could lead to the development of an OLED-based magnetic sensor, that is much cheaper and portable compared to current MRI devices. The method the researchers used is based on electrically detected magnetic resonance (EDMR) and optically detected magnetic resonance (ODMR), and is based on the change in spin behavior of electrons that are close to magnetic fields

Researchers at the University of Chicago, led by Sihong Wang (above) and Juan de Pablo, developed a stretchable OLED device that uses TADF emitters to enable high efficiency and high stretchability.

The researchers say that this is the highest-efficiency stretchable display demonstrated to date, as all previous designs used fluorescent OLED emitters. The TADF stretchable device achieves 10% EQE and a stretchability of 125%. The substrate of this new device is a newly synthesized polymer.

This is a sponsored post by Nanomatch

Using their in-house virtual design tools, Nanomatch developed a new class of emitters that enables the production of stable, fluorescent OLED devices with close to 100% internal quantum efficiency also in the blue color range.

The specific class of fluorescent emitters facilitates the generation of only singlets with radiative decay of the order of 10-8s, thereby eliminating quenching processes induced by long-lived triplets. Having filed the patent end of February 2023, Nanomatch is now looking for partners to commercialize this new concept in order to realize efficient, stable blue OLEDs on an industrial level.

Researchers at the University of St Andrews and the University of Cologne developed a polariton-based OLED device that offers angle-independent narrowband emission.

Polariton-Exciton quasiparticles are created when an OLED material is inserted into a high-quality microcavity. The researchers explain that by sandwiching the OLED device between two "mirrors", strong coupling and hybridization of light and matter can occur. This leads to the creation of the polariton particles. 

Researchers from Korea's Pusan National University have developed a new low-cost hole injection layer (HIL) material for solution-processed OLEDs, achieving higher efficiency and lifetime compared to the current state-of-the-art.

The new material is solvent-resistant (>99%) and thermally cross-linkable. The researchers used this material to create a solution-procssed red phosphorescent OLED device. The researchers placed the material between the ITO electrode and the HTL material, thus achieving photo-crosslinking of (poly-TPD) as HTL on top of crosslinked HIL. 

Researchers from Germany's Max Planck Institute, led by Prof. Paul W.M. Blom, are looking into single-layer OLED devices (in which a single emitting layer is sandwiched between two electrodes), with an aim to match their efficiencies to those of common multilayer OLED stacks, like the ones used in commercial OLED displays.

Current OLED architectures utilize multilayer stacks of materials, in order to increase the performance and lifetime of OLED devices. But according to the latest findings by Prof. Blom, equal efficiencies can indeed be met with single-layer TADF OLED emitters - and there's no fundamental reason or major benefits that arise from multilayer OLEDs.

Industrial inkjet printing developer Notion Systems announced that is has been selected by the Institute of Chemistry, Chinese Academy of Sciences (ICASS) for organic material R&D. Notion Systems worked together with its partner YixinTech as its system went through a long comparison against other inkjet printers in the market.

ICCAS is a multi-disciplinary research institute dedicated to basic research in broad fields of chemical sciences. One of its major research areas is organic materials for display applications.

In May 2022 we reported that LG Display is looking into adopting a microLens array in its large OLED TV panel architecture. The microlens layer could boost brightness by up to 20%, which will also increase efficiency (if brightness is kept as before). According to a new report from Korea, LGD is progressing in its project and estimates that the first MLA (Micro Lens Array) OLED panels will enter production in 2024.

MicroLens array structure, University of Michigan

The original report in May stated that LGD could actually begin producing MLA OLEDs as early as in 2022 - but it seems as this was overly optimistic. Earlier this year, LGD demonstrated a 77" 8K MLA WOLED panel.