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:

Panasonic's 4K OLED at IFA 2013

Some web sites are reporting that Panasonic is set to unveil a 20" 4K OLED tablet at the IFA 2013 event next week. Those sites are relying on auto-translated Japanese text. But in fact the company will not show such a tablet. In an English PR, Panasonic says they will show a 4K 20" tablet and a 4K OLED panel prototype - those are two different devices.

I'm guessing Panasonic's 4K OLED panel will be the same 56" 4K (3840x2160) OLED TV panel shown at CES 2013. This panel was made using an "all-printing" method. Sumitomo Chemical revealed that this TV prototype used 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.

Philips, Merck and Audi developed 3D OLED prototypes for the Audi TT

Audi, Philips, Automotive Lighting, Merck and the University of Cologne successfully concluded an OLED research project (called OLED 3D), and developed the world's first large-area 3D OLED car rear lighting panels and installed a prototype on an Audi TT.

A 3D OLED means that the OLEDs have a curved surface - not just in one direction. These are glass based panels. It's not flexible glass (like Corning's Willow glass), it's the regular glass Philips are using in their regular OLEDs, but curved. The material used (made by Merck) are soluble, and the production process is described as "web printing" by Philips (I'm not sure what is meant by that).

Researchers develop OLED-based "sleep mask" to treat sight loss noninvasively

Researchers from Northumbria University and PolyPhotonix developed a new OLED-based "sleep mask" that can be used to treat sight loss noninvasively. The researchers say that this new device is the world's first noninvasive primary-care treatment for diabetic retinopathy and age-related macular degeneration (AMD).

The researchers are already doing extensive clinical trials (at the home). They say that if this proves useful, it will be much cheaper than current treatments (and it's also non-invasive).

Sumitomo developed a new PLED inkjet printing technology

Sumitomo Chemical announced it has developed a new PLED inkjet-printing technology that achieves 423 PPI on glass substrates sized 370x470 mm. We don't have more information about Sumitomo's new production process, but apparently it isn't ready for commercialization yet as the company says they will "continue to improve the performance and process of PLED materials".

Panasonic printed P-OLED 56-inch OLED prototype

Panasonic used Sumitomo's PLED materials in their 56" 4K2K printed OLED TV prototype shown at CES 2013. Panasonic and Sumitomo has been collaborating on OLED TVs since 2009. The companies hope that ink-jet printing will enable them to lower the production costs of OLED panels compared to evaporation based production. Panasonic aims to launch their first OLED TVs in 2015. The company is collaborating with Sony, and may setup a production-JV together (although if this happens, it's not clear which production technology will be used).

Sumitomo shows flexible, printed, structured PLEDs, will bring them to market by early 2015

Sumitomo Chemical unveiled new flexible PLED lighting panels. These structured panels (they have a patterned printed on them) are produced in an ink-jet printed process. Sumitomo showed several lamp prototypes, including the one shown below:

Sumitomo plans to start volume production of such panels by March 2015 (fiscal year 2014) - using both ink-jet and roll-to-roll processes. They still need to extend the lifetime of their panels, improve the luminance performance and improve their production yield rates.

CPI posts some updates on their OLED developments

The UK's Centre for Process Innovation (CPI) posted some updates on their OLED program. They have recently produced defect free OLED lighting samples. They managed to produce panels that has large (over 250 cm2) emissive areas (they are producing these panels on 8" substrates and so could exceed 160x160 mm panels).

CPI 154x154 OLED lighting sample photo

The CPI developed two kinds of panels - the first uses small molecule materials and the second uses full solution-processable PLED materials. They have also produced samples that use a hybrid structure with a PEDOT layer (deposited using a slot die process) with an evaporative emissive layer (that has better efficiency and performance compared to the PLEDs). The 154x154 mm example shown above is the hybrid structure.

OTS corporate presentation video shows the PCA-48 4.5-Gen ink-jet processing line

OLED Technologies & Solutions (OTS) released a new corporate presentation video which introduces the company and their new inkjet-printing based OLED processing line, the PCA-48:

The PCA-48 line is a 4.5-Gen (730x920 mm) line that incorporates TFE, Ink-Jet Printing, and high vacuum transportation technologies. OTS uses Merck polymer and Small-Molecule materials and their production line supports all substrates (including a-Si using Ignis' technology). OTS that they can deliver and install a complete production line within 12 months, and a single line will be able to produce 40 million smartphone displays in a year. This is the line that AIV-BEX wants to use in their proposed AMOLED production fab.

Nanomarkets sees a $4.6 billion OLED materials market in 2020

Nanomarkets published a new edition of their OLED Material Market report, and they have some interesting forecasts and insights. Basically the company is upbeat on OLED displays for mobile devices, and the OLED TV market as well. While they are still cautiously optimistic that the long-term prospects for OLED lighting, they say that it will take many more years for this to become a major outlet for OLED materials.

Nanomarkets projects that the total market for OLED materials will grow from about $450 million in 2013 to over $4.6 billion by the end of 2020 - mostly from mobile displays and OLED TVs. Core OLED materials (emitters, hosts, dopants, HIL, HTL, etc. but excluding substrates, encapsulation, electrodes, etc.) will grow from $265 million in 2013 to over $1.6 billion by 2020.

Circularly polarised CP-OLED from Helicenes may enable simpler 3D OLED displays

Researchers from the Imperial College in London are researching the usage of Helicenes as emitter materials in OLED panels. Helicene based PLED emit circularly polarized light (they call these CP-OLEDs) and these may be useful for 3D OLEDs and other optical and photonics applications.

Helicenes are thermally-stable polycyclic aromatics with helically-shaped molecules. These molecules has unique structural, spectral, and optical features. The researchers found that when these molecules are used as emitter materials in OLED panels, they emit a light that is circularly polarized (not 100% though).

EMDEOLED developed the world's first inner-coated OLED light bulb

EMDEOLED is a German company that is developing an OLED based light bulb for residential lighting in collaboration with the University of Technology Braunschweig. Basically the idea is that using an inner-coating process, they are creating a replacement for regular bulbs in which the glass is coated from the inside. They have developed their first prototypes, shown below (unfortunately they did not disclose any technical details):

EMDEOLED's OLEDs are ITO-free, and they have actually developed two prototypes - one with PLEDs and one with SM-OLEDs. The company says that the inner coating results in a very high material yield (and so hopefully will be cheaper than flat OLEDs). The OLED bulbs are also easy to seal as the glass actually protects the OLEDs from the outside.

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