Article last updated on: Feb 10, 2019

OLED is an emerging display and lighting technology that enables beautiful and efficient displays and lighting panels. Thin OLEDs are already being used in many mobile devices and TVs. Polymer-OLEDs (or PLEDs, also used to be called P-OLEDs) are OLED devices made from polymer (large-molecules) materials.

14-inch P-OLED prototype by CDT
14-inch PLED prototype (CDT)

PLEDs vs SM-OLEDs

Basically you can make OLEDs from two kinds of materials: small-molecule (SM-OLED) or large-molecules, or polymers. Virtually all OLED displays on the market toady are using Small Molecules, and are produced using evaporation processes.

PLED (P-OLED) materials do not perform as good as SM-OLEDs in terms of lifetime and efficiency, but are easily soluble and so can be easily adapted for printing and other solution-based processes. In the past some believed that the soluble nature of PLEDs mean that these materials will be the future of OLED displays, but that has not been the case yet. There has been great progress in evaporation processes and materials - and also in soluble SM-OLEDs.

CDT / Sumitomo

UK-based Cambridge Display Technology (CDT) is the company that holds the basic patents for PLED technologies. The company licensed its technology to several companies, including Philips, Seiko Epson, Osram, Dupont and Delta Optoelectronics, but it does not seem as it anyone is pursuing PLEDs at the moment besides Sumitomo Chemicals (which owns CDT).

Sumitomo and CDT are still developing PLED materials and panels. Sumitomo is providing emitter materials for JOLED (who started low volume production of printed OLED monitor panels in December 2017, see below) and is hopefully gearing up to start mass production of its own OLED lighting panels.

JOLED's PLED

JOLED (Japan OLED) was established in August 2014 by Japan Display, Sony and Panasonic with an aim to become an OLED medium display (10-30 inch) producer. JOLED is using a printing process which should result in lower cost production (but of lower performance displays) compared to evaporation printing.



JOLED is using PLED materials produced by Sumitomo (see above). The company started commercial low-volume production of its 21.6" 4K OLED panels towards the end of 2017 at the company's pilot 4.5-Gen line. JOLED has announced plans for a mass production 5.5-Gen line that will be established in Nomi City, Ishikawa Prefecture, by 2020.

Panasonic's 2013 56" OLED TV prototypes

In January 2013 Panasonic unveiled a 56" 4K (3840x2160) OLED TV panel prototype that was produced using an all-printing method and PLED materials. Panasonic says that all the organic materials were deposited using ink-jet printing. The panel's TFT substrate was supplied by Sony (and actually made by AUO. It's an Oxide-TFT panel) as part of the two companies collaboration. The lifetime and efficiency of this TV was not disclosed.

In December 2013 Sony and Panasonic announced that they are canceling the OLED TV JV. Panasonic is now producing OLED TVs - but these use WRGB OLED panels produced by LG Display.

PLEDs in the market

In the past, several PMOLED makers produced PLED based small-sized display modules, mostly alpha-numeric and single-color panels. As of 2018, PLED PMOLEDs are not in production any more.

P-OLED module by OSD

PLED PMOLED module (OSD)

P-OLED (PLED) vs pOLED

P-OLEDs, or PLEDs, are a class of OLED materials. Somewhat confusingly, LG Display is branding its mobile flexible AMOLED displays as pOLEDs (plastic OLEDs). For more information on LGD's pOLEDs, click here.

Further reading

The latest PLED news:

LunaLEC's new spray technology creates 3D LEC objects in air

In 2012 we posted about light-emitting electrochemical cells (LEC), a cheaper (but less efficient) flexible alternative to OLED lighting. Back then, three Universities (in Sweden and Denmark), involved with Polymer LEC (P-LEC) research, launched a company called LunaLEC to develop and commercialize the technology.

Now LunaLEC unveiled a new technology that can be used to fabricate 3D LECs in air using spray-spintering. This fault-tolerant fabrication technique can produce multi colored large-area emission patterns via sequential deposition of different inks based on identical solvents. The technique can also be used to deposit LECs on complex-shaped surfaces - for example the fork you see above. This is done in-air without the use of cleanrooms.

Sony and panasonic cancel their OLED joint-development project

In June 2012, Sony and Panasonic announced that two companies will jointly develop technologies for OLED TV panels mass production. Now the two Japanese companies announced that they canceled the joint development. The two companies will continue to develop OLED technologies independently, but will focus on UHD LCDs. Sony and Panasonic explains tha OLED TVs did "not deliver the growth originally envisioned, and are unlikely to be commercially viable in the near future.

Sony 56-inch 4K OLED TV prototypeSony 56-inch 4K OLED TV prototype

In January 2013 (during last year's CES event), the two companies unveiled 56" 4K OLED TV prototypes. The Oxide-TFT substrate was produced by AUO. We know that Panasonic used an ink-jet printing process, Sumitomo's PLED materials and a direct-emission architecture. Sony used their own Super Top Emission OLED technology and evaporable OLED materials.

Kateeva finally unveil their YIELDjet OLED TV inkjet printing system

Kateeva is a US based startup that was established in 2009 to develop OLED ink-jet deposition technology originally developed at MIT. The company has been been in stealth-mode for years, and now finally they have unveiled their technology and system, branded YIELDJet.

So YIELDJET is an inkjet printing system that can be used to produce OLEDs in high volume. Kateeva claims that their system, the first one engineered from the ground up for OLED mass production, will dramatically improve yields and drive production costs lower. Kateeva says that this was achieved by three major technical breakthroughs: is features a production-worthy pure nitrogen process chamber, which doubles the lifetime in certain applications, it reduces particles by as much as 10X thanks to a specialized mechanical design and it offers exceptional film coating uniformity with a process window that’s 5X wider than standard technologies.

Novaled, CDT and others to co-develop low-cost high-performance soluble OLED lighting technologies

The EU launched a new project (called ENAB-SPOLED) that aims to use solution-based OLED materials to enable high performing cost competitive OLEDs for the lighting market and to develop a functional luminaire demonstrator. More specifically, the project partners will develop new materials (transport materials, emitters), new optical technologies for light guiding, and also process technologies for solution processing of small molecule and PLEDs.

This 2-year project has a budget of €4 million and is supported by Germany, Austria and the UK. The project partners are Novaled, Cambridge Display Technology, Tridonic, Zumbotel, the University of Durham and the Fraunhofer IAP. More information can be found here.

New oligomer OLED molecule emits non-polarized light, to enable more efficient PLEDs

Researchers from the University of Utah, Bonn and Regensburg developed a new wagon-wheel (or rotelle-pasta) shaped OLED molecule that emits non-polarized (random) light.Those oligomers, or wrapped-up polymers may enable OLEDs more efficient than polymer based OLEDs (PLEDs).

The researchers explain that current poylmer OLED molecules (which are shaped like spaghetti pasta, to continue the same metaphore) emit polarized light. Some of that light get trapped inside the OLED device and this makes it less efficient. They say that up to 80% of the generated light may be trapped in the OLED because it is polarized.

Panasonic's OLED program is progressing fast, will launch 56" UHD OLEDs in Q4 2013?

According to the OLED Association, Panasonic said that they are progressing fast enough to launch the 55" (probably 56") UHD OLED TV in Q4 2013. Panasonic will start mass production in its Himeji Pilot Gen-5.5 line (which means initial production will be very limited). If this report is true it means a real acceleration as Panasonic previously said they will only be ready in 2015 (although you may say that the current Himeji line will not be real mass production in any case).

Panasonic OLED TV prototype, IFA 2013

Panasonic's OLED TV panel, unveiled in January 2013, is produced using ink-jet printing and uses an RGB subpixel matrix (direct-emission). Panasonic is using Sumitomo's PLED materials, and AUO's oxide-TFT Substrates. The company is collaborating with Sony on OLED technologies.

New technology may lead to true white emitting OLEDs based on platinum-doped polymers

Researchers from the University of Utah developed a new polymer light emitting device that can be tuned to emit light of different colors, including white (without the need to mix several emitters). The new material is a polymer molecule doped with platinum. The same material can also be used to develop efficient OPVs or Spintronics-based memory devices.

The device currently being developed at Utah isn't an OLEDs as it only emits light when stimulated by other light (such as a laser) and not when simulated by an electrical current. But the researchers say that a white OLED based on this technology is possible and predict that it will be developed within two years. The current device isn't actually white, it emits colored color (more on this below) and they say it will take about one year till they manage to develop a white Pt-1 device.

Utah professor explains the science behind the Spin-OLED device

In 2012 we posted about a the Spin-OLED, a new spin-polarized polymer efficient OLED device developed at the University of Utah and the Israeli Technion. Now Professor Z. Valy Vardeny from Utah gave a talk (titled "Spin Effects in Organic Optoelectronic Devices") describing the Spin-OLED in more details:

Professor Vardeny also gives an introduction to organic Spintronics and introduces the hybrid organic/inorganic spintronics device and explains how OPV can be enhanced by spin 1/2 radical additives.

Panasonic shows OLED TV and lighting prototypes at IFA 2013

As promised, Panasonic showed 56" 4K (3840x2160) OLED TV panel at the IFA 2013 exhibition. The company had several prototypes on display, and I believe these are the same panels as the ones Panasonic unveiled at CES 2013 in January 2013.

Panasonic panels are made using an "all-printing" method, and Sumitomo Chemical revealed that these prototypes use the company's PLED materials. Panasonic's panel uses a substrate (probably Oxide-TFT) provided by Sony (which are actually made by AU Optronics) - as part of the two companies collaboration. According to the latest reports, they only plan to start OLED production at around 2015.

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