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.
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 (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.
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.
The latest PLED news:
A report from Japan suggests that Panasonic decided to withdraw from the OLED TV business as production costs are too high for the Japanese company. According to the report, Panasonic hopes to sale its OLED business to Japan Display (an agreement is expected next month).
This report is not confirmed yet. It is rather surprising as Panasonic's OLED business is focused on TV panels, while Japan Display is producing small/medium displays. In the past few years, Panasonic focused on printing technologies using Sumitomo's PLED materials.
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.
Sumitomo will exhibit a PLED installation called OLED Cosmos, designed by Motoko Ishii. This installation will use new dual-color OLED panels. These panels (produced using printing technologies) use two distinct colors.
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.
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 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.
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.
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.
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'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.
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.
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.