Technical / Research - Page 3

Researchers from the University of Lisbon and the University of Modena have developed a transient OLED device, that can completely dissolve inside a human body without affecting homeostasis. This technology can be used to create safe biomedical devices.

OLED based phototherapy can be used to sense or stimulate specific cellular responses, and this has been developed and even commercialized in many applications. But this new research targets phototherapy that functions from within the body.

The UK's Engineering and Physical Sciences Research Council  (EPSRC) has awarded 2.9 million GBP (around $3.9 million USD) to a research group at the University of St Andrews led by Prof. Eli Zysman-Colman, to develop solution-processable stable and efficient blue OLED emitters, based on Prof. Zysman-Colman TADF OLED emitters research.

The research group will establish a 5-year open fellowship, that will form a team of 6 researchers. The final objective is to develop an automated film formation and characterization platform. While the grant is academic, this technology may end up being commercialized by SolOLED. 

Researchers at Kyushu University, and Soochow University, led by Prof. Chihaya Adachi, have designed a new strategy to develop MR (multiple resonance) TADF OLED emitters that offer both a narrowband emission and adequate FMOs energy levels, by manipulating the frontier orbital levels.

The researchers explain that the energy level alignment of frontier molecular orbital (FMO) is essential for controlling charge carrier and exciton dynamics in OLED devices. Current MR emitters mostly suffer from inadequate FMO levels. In this research, which used a blue (459 nm) MR OLED emitter, a wavefunction perturbation strategy was proposed by incorporating cyano motifs at peripheral sites of MR backbone to adjust the energy levels. The approach significantly shifted the HOMO levels without compromising the color purity. The researcher report that detrimental carrier trapping effect was eliminated, enhancing external quantum efficiency to exceeding 23%, maintaining around 20% at 1000 cd m−2, and improving the device stability.

A team of researchers led by Prof. Forrest at the University of Michigan designed a new highly promising blue phosphorescent OLED emitter. The researchers demonstrated a tandem device that is based on these new emitters, that increased the lifetime 250 times compared to a conventional single-stack PHOLED device. This new design provide a real path towards a commercial blue PHOLED device.

To achieve that dramatic increase in lifetime, the researchers applied a polariton-enhanced Purcell (PEP) cathode and anode, to create a so-called PEP-PHOLED device. The blue color coordinate is CIExy = (0.14, 0.12). The researcher say that this double-sided PEP effect can be integrated with other established lifetime-extending technologies. 

Researchers from Korea's Pohang University of Science and Technology (POSTECH) have developed the world's first pixel-based local OLED sound technology, which enables each pixel of an OLED display to simultaneously emit different sounds, essentially allowing the display to function as a multichannel speaker array. The researchers demonstrated the technology using a 13-inch OLED panel.

The researchers created the sound system by embedding ultra-thin piezoelectric exciters within the OLED display frame. These piezo exciters, arranged similarly to pixels, convert electrical signals into sound vibrations without occupying external space. As a result, each pixel can act as an independent sound source, enabling Pixel-Based Local Sound technology. The researchers also developed a method to completely eliminate sound crosstalk, ensuring that multiple sounds from different regions of the display do not interfere with each other.

Researchers from Tsinghua University have developed a deuterated exciplex-forming host material for deep-blue phosphorescent OLED devices, with improved stability.

The researchers say that this research unveiled an external deuteration effect on OLED dopants, which reduces the shoulder emissions for slightly blue-shifted colors and also accelerates the radiative decay rates. This leads to improved photoluminescence efficiency.

LG Display announced that it has successfully verified the commercialization-level performance of blue phosphorescent OLED panels on a mass production line. LG is using a hybrid two-stack Tandem OLED structure, with blue fluorescence in the lower stack and blue phosphorescence in the upper stack. This enabled LG to achieve a power consumption reduction of 15%, while maintaining a similar level of stability to existing OLED panels.

The blue PHOLED emitter was supplied by Universal Display. LG Display says that it has independently filed patents for its hybrid blue phosphorescent OLED technology in both South Korea and the United States.

Visionox announced that it plans to invest 5 billion Yuan (around $690 million) to construct a global flexible AMOLED R&D center in Kunshan, China. Visionox says this massive R&D initiative will help it to expand the application of AMOLEDs into new applications. The Kunshan Economic and Technological Development Zone will provide assistance (including financial backing) to Visionox in building the new center.

The focus of this new R&D center will be on OLED materials, production equipment and core foundational technologies. Visionox plans to look into new OLED applications including AR and VR devices, automotive displays, medical imaging, and more.

Researchers from France's Universite de Rennes and the Université Paris-Saclay have designed new graphene-based OLED emitters that outperform all previous graphene emitters.

The researchers designed green emitters based on rod-shaped nanographene materials containing C60-tBu8 materials, and incorporated these into a benchmark OLED device.  The OLED devices containing the C60-tBu8 exhibited current and power efficiencies (CE and PE) of 2.27 cd·A^–1, 0.28 lm·W^–1 and luminance of 164 cd·m^–2.

Noctiluca, technology company listed on the Warsaw Stock Exchange, has developed a breakthrough material for use on one of the OLED display layers. In laboratory tests in Korea, NCEIL-4 demonstrated a 15-fold increase in blue pixel lifespan while reducing power consumption. “This could be an important step forward in the ongoing race for blue in the OLED market,” says Mariusz Bosiak, the company’s CEO.

Race for blue

Noctiluca is a deep-tech company in the material sciences, developing high-performance materials (HPM) that enhance the functionality of OLED devices and other products from the broader field of organic electronics.

Leading market players, including Noctiluca, are particularly focused on developing the most desirable blue light emitter, as the vast majority of light emitted by displays is in this color. These materials are important components of OLED displays, determining attributes like image quality, color saturation, brightness, and durability.

Despite extensive research efforts, no company has yet succeeded in completing a fully optimized blue emitter. As a result, first-generation blue emitters—an inefficient technology from the 1990s—are still widely used today.