Kyulux dramatically improves the performance of its blue HF emitter

Kyulux announced that it has developed a new blue Hyperfluoresence/TADF OLED emitter. Kyulux managed to extend the lifetime of the material and reached 100 hours at LT95 (@ 750 cd/m2) while maintaining a high EQE of 26% - 22% at 1,000 cd/m2. The emission wavelength is 470 nm.

Kyulux says that its blue Hyperfluorescence emitter is the world’s top performing material at the moment. Kyulux now aims to work together with OLED panel makers to improve the systems further by optimizing the device structure and the rest of the OLED stack in pilot production lines.

Kyushu University researchers use singlet fission to achieve near-infrared OLED emitters with >100% IQE

Researchers from Japan's Kyushu University developed a new technology called singlet fission that enables near-infrared OLED materials to surpass the 100% limit for exciton production - or achieve an internal quantum efficiency (IQE) of over 100%. Singlet fission was already used in OPVs, but this is the first time that it was demonstrated with OLEDs.

SInglet fission OLED process, Kyushu University

Achieving over 100% is possible because at 100% IQE all charges form excitons that emit light. The new technique splits the energy from a high-energy excitons into two low level ones. The new OLED emitter materials use molecules in which singlets can transfer half of their energy to neighboring molecules while keeping half of the energy for themselves - each singlet creates two triplets. The emitters emit near-infrared light.

Researchers increase OLED efficiency by over 15% by using ultra-stable film formation

Researchers from the Universitat Autònoma de Barcelona and TU-Dresden have demonstrated that ultra-stable film formation can be used to to improve the performance of OLED devices.

Ultra-stable film formation to improve OLEDs

The researchers grew (using evaporation) the organic materials as ultrastable glasses - a growth condition that allows for thermodynamically most stable amorphous solids. Testing four different phosphorescent emitters, the researchers show significant (over 15%) increases of efficiency and operational stability. The researchers also say that these growing conditions are expected to even be more useful for TADF materials.

Researchers develop a sub-electrode micro-lens array that can increase the light output in OLEDs by a factor of 3

Researchers from the University of Michigan developed a new method to cost-effectively extra more light out of OLED displays. To achieve that, the researchers used a Sub-Electrode Micro-Lens Array (SEMLA) placed between the bottom transparent ITO electrode and the glass substrate. Testing on green and white PHOLEDs, the researchers say the SEMLA enhanced light output by a factor of 2.8 (green) and 3.1 (white) compared to a similar device without the lens array.

OLED micro-lens array (Michigan)

The researcher say that such an array can be fully transparent and has no impact on the sharpness of the display. The hexagonal array of 10 μm lenses can be fabricated using conventional photolithography methods which are quite cost effective. Such a micro-lens array does not change the actual OLED production process.

Pixelligent raised $7.6 million, is working with Kateeva to adopt its materials for OLED inkjet printing

US-based high-index material maker Pixelligent Technologies announced it raised $7.6 million in a new funding round that will help the company to further drive its product commercialization and accelerate global customer adoption.

This round was led by the Abell Foundation, and included other Baltimore-based investors. This found also included strategic investments from Kateeva and Japan-based advanced material producer Tokyo Ohka Kogyo.

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.

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.

ETNews: Samsung is developing hybrid QD-OLED TVs

ETNews posted an interesting article, claiming that Samsung Display is developing a new TV technology that combines OLED emitters with quantum-dot photo-luminescence materials. The basic idea is to use blue OLED emitters and then convert the blue light to white light using quantum-dots combined with color filters (QDCFs) to add red and green colors.

Samsung OLED TVs (2013)

This seems to be a rather complicated design, but it could be much easier to produce compared to a true RGB OLED TV, as there is no need for precise OLED patterning. This is similar to LG's WRGB OLED TVs which use a white OLED source (made from yellow and blue emitters) and color filters on top.

The EU SOLEDLIGHT project developed solution-processed R2R OLEDs, reports interim results

The SOLEDLIGHT (Solution Processed OLEDs for Lighting) project was launched in 2015 by a European consortium with an aim to develop cost efficient, roll-to roll (R2R) solution processed OLEDs, including their integration in prototype multiple-panel OLED lighting systems and luminaires.

The SOLEDLIGHT consortium (which is coordinated by the University of Valencia and includes OSRAM and Solvay) reported that it managed to develop multi-layer R2R solution processed OLEDs that achieved a power efficiency of 20 lm/W. This is still not up to par with evaporation-based OLEDs, but the project partners aim to achieve 100 lm/W (and 15,000 hours) by the end of 2017.

IKEA launches its first OLED lamp, the Vitsand chandelier

IKEA launched its first OLED lamp, the Vitsand - a chandelier with 7 OLED panels. The Vitsand provides 700 lumens at 2700K. Each panel is about 77 lm/W (total 7W). The lamp is dimmable, and the panels unfortunately cannot be replaced.

IKEA Vitsand OLED photo

The Vitsand is now available in IKEA Europe for €199. It is great to see OLED lighting enter a retail store like IKEA, even though the price is still very high. The panels are likely made by LG Display but we are not sure.