Technical / Research

University of Houston Professor receives NSF award to develop efficient blue OLED emitters

Professor Homas Teets from the University of Houston has been awarded a $589,000 National Science Foundation (NSF) CAREER Award to explore new synthetic strategies for producing photoactive organometallic compounds.

Specifically, Teets will use the award in three research areas - efficient and long-lasting blue OLEd emitters, near-infrared (NIR) emitting compounds and photocatalysts for organic synthesis capable of light-induced electron transfer. The grant will also fund educational projects aimed at children from kindergarten through high school.

TCL is developing hybrid QD-OLED display technology

TCL unveiled that the company is developing a new hybrid display technology that uses a blue OLED emitter coupled with red and green QD emitters. All three emitter materials will be combined and printed using ink-jet printing technology. TCL calls this technology H-QLED and this could prove to be the technology of choice for TCL's future high-end emissive TV displays.

TCL H-QLED slide (OLED Korea 2019)

It seems as TCL believes that commercial-level red and green QD emitters will be achievable in the future, but blue QD emission will be more difficult to develop, and hence it will rely on OLED emitters. TCL did not disclose more details - but this R&D effort is being performed at the company's Juhua Printing platform.

Updates from NTHU's blue-hazard free OLED lighting projects

In 2014 we reported that the Tai-Yah (also called Atayal) tribe, the "dark tribe", has started to test National Tsing-Hua University's blue-free OLED lighting panels (produced by WiseChip).

These early candle-light street OLEDs were not suitable for that environment, and NTHU researchers say that mountain dew rapidly shorted the wires. But not NTHU has stepped up its efforts and teamed up with First-o-Lite to produce a new version of its panels. This time the researchers are positive that its new panels will enable the entire village to adopt blue-hazard free lighting,

The NSF awards Molecular Glasses with $225,000 to develop non-crystallizable TADF host materials

US-based OLED material developer Molecular Glasses received a $225,000 SBIR Phase I grant from the National Science Foundation to develop non-crystallizable charge transporting organic materials as OLED functional layers and thermally activated delayed fluorescence (TADF) emitter-layer hosts.

Molecular Glasses OLEDIQ advantages chart The NSF explains currently used OLED host molecules tend to crystallize and are poor solvents for the emitting molecules leading to decreased light emission efficiency and shortened device lifetime. Molecular Glasses' innovation uses isomeric mixtures of designed molecules that are amorphous and non-crystallizable in all three layers.

USC researchers develop copper-based OLED emitters that could pave the way to an efficient long-lasting blue OLED

Researchers from the University of Southern California (USC) led by Mark E. Thompson (who was the first to report on efficient phosphorescent OLEDs, later commercialized at UDC) developed a new copper-based phosphorescent OLED emitter compound, that could have several advantages to the currently-used iridium compounds.

USC rigid copper OLED emitter compound photo

The researchers say that copper-based emitters could be cheaper (as iridium is an expensive and rare element) - but more importantly could be the key to develop an efficient and long-lasting blue OLED emitter.

Researchers from Italy develop a graphene-based OFET for future OLED and OLET backplanes

Researchers from from the collaboration between Italy's ISOF-CNR, University of Naples "Federico II" and Università di Modena e Reggio Emilia have developed new organic n-type FET transistors based on CVD graphene sheets. The researchers say that the new process and materials they used can enable flexible, transparent and short-channel OFETs - which could be used in the future for OLED or OLET displays.

ISOF CNF CVD graphene OFET structure photo

To create the new transistors, the researchers used thermally evaporated thin-films of PDIF-CN2 (a perylene diimide derivative, specifically Flexterra's ActiveInk N1100) as the organic semiconductor for the active channel of the transistor, with the single-layer CVD graphene (grown at Italy's IIT INSTITUTE) as the electrode material

Korean researchers develop transparent and foldable perovskite-based LEDs

Researchers from Korea's Ulsan National Institute of Science and Technology developed a new perovskite-based LED (PeLEDs) which are flexible enough to fold and are also transparent. It seems as if these LEDs are similar to OLED devices and provide area-lighting and not point-lighting like inorganic LED chips.

Korean research team develops translucent PeLED that can be folded image

Perovskite-based LEDs have been demonstrated before, but this is the first time a transparent and flexible one has been developed, according to the researchers. Perovskite LEDs feature high electron mobility, good color purity, and easy color control.

Double-doping of OLED materials could double the efficiency of polymer OLED displays

Researchers from Sweden's Chalmers University have developed a new "double doping" process that basically doubles the efficiency of Polymer OLED emitter materials.

The researchers explain that doping in organic semiconductors operates through what is known as a redox reaction, in which the dopant molecule receives an electron from the semiconductor which increases the electrical conductivity of the semiconductor. The efficiency limit of current doped organic semiconductors has been limited by the fact that each dopant molecule was able to to exchange one electron only. In the new research it was shown how it is possible to move two electrons for every dopant molecule which increases the conductivity of the organic material.

Researchers develop 100% IQE radical-based OLED emission

Researchers from the University of Cambridge and Jilin University discovered that radical-based OLEDs feature highly efficient emission - in fact they believe that this discovery could be an elegant solution to the problem of in-efficient OLED emission.

First-generation OLED emitters (fluorescent emitters) have a maximum internal quantum efficiency of 25% - as only a quarter of the electrons are in a singlet-state (that emit light) while 75% of the electrons are in a triplet-state. Current ways to achieve 100% IQE are either based on doping with heavy metals (phosphorescent emission) or either based on delayed fluorescence (TADF).

Lyteus partners demonstrate the world's longest flexible OLED lighting device at 15 meters

The Fraunhofer FEP institute, the Holst Center and other partners have developed a 15-meter long OLED lighting panel, the longer OLED device ever (beating their own 2017 record of a 10-meter OLED). This work was done as part of the Lyteus, the EU's €14 million initiative within PI-SCALE.

Lyteus 15 meter OLED lighting roll
The partners in this project say that this is the first OLED produced using a new unique roll-to-roll (R2R) process that combines the performance of an evaporated OLED stack with solution processing of auxiliary layers.