Researchers from Yonsei University develop highly stretchable OLED devices

Researchers from Yonsei University developed a new OLED device that is highly stretchable. The researchers managed to build the entire device, including the substrate, conductive wires, electrodes and OLED layers, from stretchable materials.

Highly stretchable OLEDs (Yonsei University, March 2021)

The researchers say that this is the first time that the complete display device was produced from stretchable components, unlike previous efforts which have mainly focused on connecting small rigid OLED devices together to create a stretchable device.

New OLED device structure, called OPB-LET, offers promising performance

Researchers from Dresden's Technical University (TUD) developed a new OLED device structure that combine vertical organic permeable base transistors (OPBT) and OLEDs materials - organic permeable base light-emitting transistor, or OPB-LET.

The device architecture of organic permeable base light-emitting transistors (OPB-LET)

The new design successfully combines the function of a highly efficient switching transistor and an organic light-emitting diode. The OLED transistors (OLETs) are three-terminal devices combining a thin-film transistor with a light-emitting diode. Unlike previous OLETs, the OPB-LET offer high performance, thanks to the permeable base electrode located at the center of the device. The electrode forms a distinctive optical microcavity and so regulates the charge carrier injection and transport.

Researchers develop PLED-emitting temporary tatoos

Researchers from the UK's UCL and Italy's IIT developed OLED-based smart temporary tatoos. Similar to children's "sticker" type tatoos, these small devices can be transferred to the skin by being pressed and washed with water.

OLED tatoos (UCL & IIT)

Such devices could in the future be used to short-term sensors (for example to detect when an athlete is dehydrated during an event) or in fruit packaging to signal when a product has passed its expiry date.

Researchers from Germany in collaboration with Oreltech use printed silver-inks as OLED electrode

Researchers from the Helmholtz Center Berlin for Materials and Energy and the Physics Department of the Humboldt University Berlin, together with Oreltech, developed a new flexible OLED prototype that uses Oreltech's silver-inks to deposit electrodes on PET substrates.

Helmholtz Center - Humbolt Univeristy - Oreltech, silver-ink PET OLED device structure and process

The researchers report that the new device outperforms ITO-based devices in both efficiency and luminance - and they are offer better bending stability.

Densely-packaged dimer-enhanced MR-TADF emitters demonstrate high efficiency with a narrow emission spectrum

Researchers from Soochow University, in collaboration with a wide team of scientists from China and Japan (including Prof. Adachi from Kyushu University) developed a TADF emitter material compound that features high efficiency and a narrow color spectrum.

MR dimers enhanced TADF OLED emitters (Soochow University)

Up until now, most TADF emitters featured a wide spectrum, which limits the adoption of TADF materials in displays as they cannot enable a wide color spectrum. To overcome this problem companies employ a structure in which the TADF emitter is combined with a narrow-spectrum fluorescence emitter (so-called Hyperfluorescence).

Researchers develop new OLED structure that enables directional and polarized emission

Scientists from North Carolina State University and the University of Texas have developed and demonstrated a new approach for designing photonic devices. The new method enabled the team to control the direction and polarization of light from thin-film LEDs, overcoming the widely known obstacles of beam shaping that arise from their Lambertian nature. Such LEDs with directional and polarized light emission could be useful for many photonic applications.

A new approach for designing photonic devices with directional light emission image

The researchers demonstrated that this approach could be used to emit directional and polarized light from an OLED devices without external optical elements.

Kyushu University researchers developed a promising new two-unit stacked tandem Hyperfluorescence blue OLED emitter system

Researchers from Kyushu University reported that they have developed a promising new blue OLED emitter system, based on a two-unit stacked tandem hyperfluorescence OLED with improved singlet-excited-state energy transfer from a sky-blue assistant hetero-donor-type TADF (HDT-1) dopant.

Two-unit stacked tandem Hyperfluorescence blue OLED device (Kyushu University)

The research reports that the new emitter system offers a pure-blue color (CIE 0.13, 0.16), a narrow spectrum (full-width at half-maximum of 19 nm), an EQE of 32% at 1,000 cd/m2 and a lifetime of 18 hours LT95. The lifetime is still lacking, but with stricter control of device fabrication and procedures the researchers say they expect that device lifetimes will further improve to rival commercial fluorescent blue OLEDs.

Researchers develop highly efficient polarized light emitting polymer OLED devices

Researchers from the Imperial College London have devised a method to create strong chiral light emitting polymers OLEDs. These OLED devices emit efficient polarized light - which means that they could be used to create OLEDs without an anti-reflection polarizer filter and thus enable higher efficiency displays.

Chiral optical response in OLED devices (ICL)

The researchers discovered that using thin films of aligned polymer LED devices shaped like fusili pasta it is possible to emit high chirality light.

Is UDC getting ready to commercialize its plasmon OLED technology?

A couple of months ago we reported that researchers at UDC developed an OLED device with plasmonic decay rate enhancement that dramatically increase device stability. It turns out that UDC filed for two new trademark applications that seem to hint it is aiming to commercialize this technology.

UDC PLASMONLED trademark image

The two trademarks at PLASMON PHOLED and PLASMONLED, which both of course indicate that these are emitters that adopt plasmon technology.

Cambridge Isotope Laboratories - Deutreated Reagents and High-Purity Gases for OLEDsCambridge Isotope Laboratories - Deutreated Reagents and High-Purity Gases for OLEDs