Technical / Research - Page 6

Researchers from the University of Michigan developed a new OLED emitter system, based on a blue phosphorescence emitter, based on the polariton-enhanced Purcell effect. This new emitter systems offers high stability and high efficiency. 

The basic idea is to start with a light-blue (cyan) phosphorescence emitter (which offers a longer lifetime than a deep blue emitter), and placing it between two mirrors. The distance between the mirrors is controlled so that only deep blue light waves persist and are emitter from the mirror chamber. The researchers also tuned the optical properties of the OLED stack to the adjacent metal electrode which introduced a new quantum mechanical state called a plasmon-exciton-polariton, or PEP. This new state allows the organic material to emit light very fast, thus even further increasing the lifetime by decreasing the opportunity for excited states to collide and destroy the light-emitting material.

Researchers from Korea's Dongguk University developed a new green phosphorescent OLED emitter based on a manganese complex called MnBz. The green MnBz emitter offers high brightness and efficiency and low-cost fabrication without any heavy metals. The green emitter was also used to create a warm-white OLED device.

The new emitter is based on a a zero-dimensional manganese (Mn)-based complexes, produced via solution processing. The green phosphorescent OLED offers a record-breaking quantum efficiency of 11.42% and current efficiency of 56.84 cd A^-1. 

Toray Research Center (TRC) has launched its open online webinar focused on OLED technologies. TRC, who supplies technical analysis and support for R&D and manufacturing, invites you to attend the online lectures at no cost, to get a deeper understanding on OLED technologies and analysis of OLED devices. The webinar recordings are now accessible for two weeks.

The first lecture, titled 'current analytical techniques for displays', will focus on current techniques used for OLED analysis, including OLED layers observation by high-contrast STEM, OLED layer construction analysis by GCIB-TOF-SIMS and TOF-SIMS MS/MS and quantification analysis using LC/CAD. The same lecture will also discuss recent topics in analysis technology, including the degradation analysis of QD devices.

On November 2nd 2023, Toray Research Center (TRC) will share an open online webinar focused on OLED technologies. TRC, who supplies technical analysis and support for R&D and manufacturing, invites you to attend the online lectures at no cost, to get a deeper understanding on OLED technologies and analysis of OLED devices. The webinar recordings will be accessible from November 2nd, for two weeks.

The first lecture, titled 'current analytical techniques for displays', will focus on current techniques used for OLED analysis, including OLED layers observation by high-contrast STEM, OLED layer construction analysis by GCIB-TOF-SIMS and TOF-SIMS MS/MS and quantification analysis using LC/CAD. The same lecture will also discuss recent topics in analysis technology, including the degradation analysis of QD devices.

Dr. Kou Yoshida and Dr. Junyi Gong, from the University of St Andrews, working with Prof. Ifor Samuel and Prof. Graham Turnbull, have developed an integrated organic laser device, based on an electrically-pumped laser.

In this work, the researchers developed and electrically driven organic electronic laser, with a narrow emission spectrum and the formation of a laser beam above the threshold. The researchers have shown that indirect electrical pumping by an OLED is a very effective way of realizing an electrically driven organic semiconductor laser.

Researchers from the Tokyo Institute of Technology, Osaka University, University of Toyama and Shizuoka University have developed a fluorescent blue (462 nm) OLED device that features an ulta-low turn-on voltage of 1.47 V (at 100 nits). The researchers say this is very low, as similar commercial blue devices typically need around 4 V.

To achieve that low turn-on voltage, the researchers built a new device, as they realize that the choice of materials significantly influences the device's turn-on voltage. The device itself is an upconversion OLED.

Researchers from the Korean Advanced Institute of Science and Technology (KAIST) and the Asan Medical Center (AMC) have developed the world's first OLED-based catheter for phototherapy within internal organs.

OLED-based light therapy has been researched, and even commercialized, before, but only for external use. This is the first time that such a device has been developed for internal use.  The device developed by the joint research team is a catheter-shaped OLED platform that can be directly inserted into tubular organs like the duodenum and is water-resistant. 

Researchers from the University of Manchester, led by Prof. Alexander Romanov, developed a promising new Carbene-Gold-Arylacetylide (CMAc) OLED near UV emitter type. The researchers also detail a strategy to develop longer device lifetimes for such emitters.

The new emitter exhibits an efficiency of 1% EQE, and a lifetime of 20 minutes at a practical brightness of 10 nits (LT50). This is low compared to commercial OLEDs - but it is actually quite outstanding for such an emitter, and the researchers say that this is among the longest lifetimes for a near UV-OLED at a practical brightness ever reported. In addition, organic fluorescent and TADF emitters rarely exceed 1% EQE at practical brightness.

Researchers from South China University of Technology and Guangzhou New Vision Opto-Electronic have found that the lifetime and current efficiency of a tandem OLED device can be greatly improved by adding an ultra-thin Ytterbium (Yb) metal layer through the charge generation layer (CGL).

The experiments detail an ultra-thin Yb metal layer with low work function, high transmittance, and large atomic radii, added to a light-green tandem OLED devices. The new device exhibited a lifetime of 308 hours (T90) at an initial brightness of 10,000 cd/m² - which is 362 times (!) longer than that of a similar device without the Yb layer (T90 = 0.85 hours). The lifetime of the same material in a single-layer configuration (not a tandem device) was 49 hours (T90).

Researchers from Japan's Keio University, in collaboration with Mitsubishi Chemical Corporation, developed a new method to accelerate the design of OLED materials, using a combination of classical computing with quantum computing.

The new approach combines a 'classic' machine learning model with a quantum-classical computational molecular design. Demonstrating the new approach, the researchers discovered a highly efficient OLED emitter, a deuterated derivative of Alq₃. The new emitter is not only highly efficient, it is also easy to synthesize.