Polymer OLEDs (PLED): introduction and market status

Researchers from Hanyang University, Gyeongsang National University, and Soongsil University have developed a high-efficiency soluble blue OLED emitter based on a hyperfluorescence architecture.

The new emitter platform uses a polymer/small-molecule hybrid emitting layer composed of a polymeric thermally TADF sensitizer and a narrowband MR-TADF emitter.

For most of OLED's commercial history, the industry operated as a near-monolith: virtually every panel maker deposited RGB organic materials through a Fine Metal Mask (FMM) on 6th-generation glass (or polyimide substrates with a glass carrier), while LG Display stood as the sole practitioner of its WRGB architecture for large-area OLED production.

In recent years, we have seen the emergence of new OLED architectures, processes and materials that signal the end of this technological uniformity. In this article, we examine the different technologies, speculate how the industry is changing and where it is headed - and understand the implications for supply chain companies. 

Researchers from the University of Oxford have developed a new OLED device that, by electrically switching, can change its light emission from left-handed circularly polarized light to a right-handed one. 

The researchers explain that usually to switch between the emission polarized direction, one would need to choose a different OLED emitter molecule - a mirror image of the other molecule. In this new breakthrough, the researchers designed new OLED emitters that react to the charge transport, and the light emission differs on whether whether the charge transport is balanced or unbalanced. The materials are polymer-OLEDs (PLED) materials, that self-assemble into a highly twisted structure.

Researchers from Germany's Max Planck Institute, led by Prof. Paul W.M. Blom, are looking into single-layer OLED devices (in which a single emitting layer is sandwiched between two electrodes), with an aim to match their efficiencies to those of common multilayer OLED stacks, like the ones used in commercial OLED displays.

Current OLED architectures utilize multilayer stacks of materials, in order to increase the performance and lifetime of OLED devices. But according to the latest findings by Prof. Blom, equal efficiencies can indeed be met with single-layer TADF OLED emitters - and there's no fundamental reason or major benefits that arise from multilayer OLEDs.

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.

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.

Sumitomo Chemical announced that the company expects demand for polymer OLED materials will increase as large-area OLED displays are entering into the market. Sumitomo hopes that its OLED materials will become the standard for large-area OLED production.

The address this next phase in its OLED business, Sumitomo has decided to integrate its PLED Business Planning office into its IT-related Chemicals Sector, which will enable it to ramp up its OLED materials business through integrated operations with its IT-related Chemicals Sector, which handles display-related materials.

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.

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

Earlier this month Samsung announced the Galaxy Z Flip, its 2nd foldable smartphone - and the 6.7" 1080x2636 inward foldable HDR "Dynamic AMOLED" display uses a flexible glass cover, as opposed to SDC's previous foldable OLEDs that used a flexible polyimide cover.

Samsung now says that it is branding its ultra-thin-glass foldable OLEDs as Samsung UTG. I'm not sure what to say regarding Samsung's slogan "Tough, yet Tender" which seems to be taken out of a completely different industry.

Researchers from the Imperial College London developed a new class of PLED materials that exhibit circularly polarized luminescence. Basically this means that the new materials emit polarized light which could make for more efficient Polymer-OLED devices as none of the light will be blocked by the external anti-glare circular polarizer added to the display.

In 2013 researchers from the ICL has reported they are researching the usage of Helicenes as emitter materials in PLED devices that also emit circularly polarized light - the researchers termed these devices CP-OLED (Circularly-Polarized OLED). Helicenes materials are thermally-stable polycyclic aromatics with helically-shaped molecules.

At the OLED Korea conference, both Merck and Sumitomo detailed their latest OLED inkjet material performance.

Sumitomo is advancing with its R&D efforts, and the company says that its PLED materials will be adopted in mass production systems by 2020 (although JOLED already uses PLEDs in its displays).