Samsung researchers study the degradation of blue PHOLED materials, offer new design strategies for longer lasting blue emitters

Researchers from Samsung Electronics and the Ewha Womans University in Korea collaborated in a new study of the degradation in blue phosphorescence OLED materials. This study demonstrate the importance of controlling exciton-induced electron transfer, and more importantly provides strategies for the design of longer-lasting blue PHOLED materials.

Degradation study of blue PHOLED, exciton-inducted (Samsung/Ewha)

The researchers say that the study reveals the charge-neutral generation of polaron pairs (radical ion pairs) by electron transfer from the dopant to host excitons. According to the study, device lifetime correlates linearly with the rate constant for the annihilation of the radical ion pair.

NTHU researchers developed a di-boron TADF emitter that maintains its efficiency at high brightness

Researchers from Taiwan's National Tsing Hua University (NTHU) developed a new TADF OLED emitter material that maintains its high efficiency at high luminance. The researchers say that this new material is the world's most efficient TADF emitter at high brightness.

Prof. Zheng Jianhong, diboron OLED TADF developer, NTHU

The new material is made from two diboron-based molecules, CzDBA and tBuCzDBA. These donor–acceptor–donor (D–A–D) type and rod-like compounds concurrently generate TADF with a photoluminescence quantum yield of ~100% and an 84% horizontal dipole ratio in the thin film. The researchers synthesized a green TADF emitter that achieved a a high external quantum efficiency of about 37.8% with an efficiency roll-off of only 0.3% at 1,000 cd/m2.

Visionox's latest 7.2" foldable OLED prototype can withstand 200,000 folding cycles

Visionox developed a 7.2" foldable AMOLED display, and has tested its reliability. Visionox says that even after 200,000 folding cycles, the display still showed good reliability. Visionox also performed extensive surface hardness and ball/pen drop tests on this display.

Visionox will discuss the reliability and failure mode analysis of its foldable OLEDs at SID Displayweek 2018 in May - and will also hopefully demonstrate this new display. Visionox performed the tests on a display module that included the AMOLED panel, a touch layer and a thin circular polarizer layer.

AUO developed a transparent 13" OLED for AR applications

Taiwan's AU Optronics (AUO) developed a 13-inch 100 PPI transparent OLED display, specifically for AR applications. This is a highly-transparent display - with 68% transmittance.

AUO transparent OLED prototype

AUO 6" transparent OLED prototype (2011)

To achieve such high transparency, AUO optimized the TFT array layer stack, the OLED cathode pattern and the encapsulation. This is the first transparent OLED AUO has developed since 2011. It will discuss this new display at SID Display 2018 - and will hopefully demonstrate it as well.

ETRI develops a flexible OLED with transparent graphene electrodes

Researchers from Korea's ETRI (Electronics and Telecommunications Research Institute) developed a flexible OLED panel that use a transparent graphene electrode. ETRI will detail this new graphene-based OLED panel at SID DisplayWeek 2018 in May.

ETRI graphene-electrode OLED prototype, Apr 2017

A rigid graphene-based OLED prototype (ETRI 2017)

The researchers produced a "fully operational" 40x40 mm OLED panel that uses the pixelated graphene film as electrodes.

SEL develops a new Host-Guest system that enables red phosphorescent emitters with 5.4X the lifetime

Researchers from Japan's Semiconductor Energy Laboratory (SEL) developed a novel Host-Guest system that drastically improves the lifetime of OLED emitters. The researchers report that using this system, a deep-red phosphorescent emitter achieved 5.4 times longer the lifetime compared to the same emitter with a conventional system.

The researchers will present the new system at SID DisplayWeek 2018 in May. The new system is not only highly durable, it also satisfies the red chromaticity of the BT.2020 standard.

AGC developed an ultra-thin flexible cover glass suitable for foldable devices

Asahi Glass developed an ultra-thin chemically strengthened 0.07 mm flexible glass that has a bending stress of over 1200 MPa - which makes it possible to use this as a cover glass for foldable devices with a curvature radius of 2.5 mm or even lower.

AGC 0.1 mm flexible glass (2011)

To create this glass, AGC developed a new process that achieved 80% higher impact-failure resistance compared to glass with conventional chemical strengthening. AGC will discuss this new glass at SID Displayweek 2018 in May - and will also hopefully demonstrate it.

Researchers discover a new way to improve the current injection in OLED devices

Researchers from the Max Planck Institute for Polymer Research developed a way to improve the current injection from the positive electrode in OLED panels. To enhance the hole injection the researchers covered the positive electrode with an ultrathin layer of an organic semiconductor as a spacer layer between the electrode and the light-emitting organic semiconductor.

Current flowing through an OLED (Max Planck Institute for Polymer Research)Current flowing from an electrode (left) to the organic material (right) via a thin molecular layer (center)

The researchers say that they did not actually expect that adding an extra layer and eliminating the physical contact between the electrode and the emitting layer actually improves the electrical contact.

Merck leads a new consortium to develop quantum materials for light emission

Germany launched a new project led by Merck to develop quantum materials as light emissive sources. The three-year project is called "Exploration of quantum materials – New paths to realizing innovative optoelectronic components" (ELQ-LED) and it is supported by the German Federal Ministry of Education and Research (BMBF) and led by Merck with an aim to conduct basic research on quantum materials as light emitting sources. ELQ-LED is a three-year project that will end on the summer of 2020.

Merck hopes that ELQ-LED materials will enable ultra-pure colors, higher energy efficiency and lower production costs compared to current OLED emitters. The focus of this project will be on cadmium-free quantum materials but the partners will also develop supporting components, processes, transport materials and ink. All components developed in this project will be printable, and the project will test its developments in display prototypes and automotive tail light demonstrators.

KAIST researchers develop new technology to deposit OLED materials on extremely thin fibers

Researchers from Korea's KAIST institute developed a technology to deposit OLED materials on thin fibers, ranging from 90 to 300 micrometers. The OLED on fibers had a luminance of 10,000 cd/m2 and efficiency of 11 cd/A.

KAIST OLEDs-on-fiber photo

The researchers developed a unique OLED device architecture, which they say is more suitable for coating on fibers. The researchers also developed a "deep coating" process to deposit the OLEDs, which works under 105 degrees Celsius.