Technical / Research - Page 106

In July 2008, I had the chance of interviewing Gildas Sorin, Novaled's CEO. Novaled is engaged in the commercialization of the new generation of OLEDs. Novaled developed an innovative doping technology (Novaled PIN OLED) enabling large area OLED display and lighting.

Novaled claims to deliver the highest power efficiencies in combination with longest lifetimes and holds several OLED world records.

Novaled, established 5 years ago, is located in Dresden, Germany. Dresden city is becoming the biggest European organic electronic centre with a network of university, R&D centers and companies acting in the organic fields.

Merck KGaA and DELO Industrial Adhesives announced today that they have formed a strategic partnership in the field of OLED technology. Within the scope of their agreement, the companies plan to develop future system solutions for OLED applications. The companies will join forces to market OLED adhesive products from DELO through Merck’s extensive marketing and sales channels.

In addition, Merck and DELO intend to develop innovative materials for improved OLED sealants that will facilitate the entry of OLEDs into large-format display applications. OLEDs show a high potential as the display technology of tomorrow and already are being used in MP3 players and cell phones. Within the OLED technology, Merck offers light-emitting materials while DELO offers new adhesive systems required to produce OLEDs.

Merck’s OLED materials are characterized by high quantum efficiency and longevity and the adhesives developed by DELO reliably seal off the sensitive metal layers from oxygen and moisture. This considerably extends the life of OLEDs. 

In July 2008, I had the chance of interviewing Dr. Michael Fiebig from OSRAM Opto Semiconductors. Dr. Michael Fiebig gained his PhD in Physics at the University of Hanover in 1998. He joined OSRAM Opto Semicondutors in 2001, and since 2008 he is leading the Marketing and Business Development in the business segment Solid State Lighting at OSRAM Opto Semiconductors.

OSRAM is part of the Industry sector of Siemens and one of the two leading lighting manufacturers in the world. Its subsidiary, OSRAM Opto Semiconductors GmbH in Regensburg (Germany), offers its customers solutions based on semiconductor technology for lighting, sensor and visualization applications. OSRAM Opto Semiconductors has production sites in Regensburg (Germany) and Penang (Malaysia).

The Japanese government will team up with several Japanese companies to develop key-technologies for producing large-size OLED panels. The aim is to cut the development cost for the Japanese companies, to be better able to compete against Samsung and LG, and the Japanese government will pitch in around 32$M.

The project will also try to make the displays more efficient and have longer lifetime.

One report says the project will run till 2013, another that it will run until 2015, and the aim is to produce 40" OLED TVs by then. We'll have to wait and see...

The companies include -

• Sony
• Toshiba
• Matsushita
• Sharp
• Idemitsu Kosan
• Sumitomo chemical
• Dainippon Screen Mfg
• Shimadzu
• Hitachi

Interesting to see Sharp in there, after having stated that "OLEDs will not threat LCD for at least a decade".

Plextronics completed a $590,000 project with USDC to produce a new HIL technology that is expected to improve device performance by reducing surface roughness; improving charge injection; and allowing fine-tuning of work function. The materials that Plextronics developed utilize a new approach to conductive polymer chemistry that enables significant performance improvement. These HIL products will be cost competitive and a suitable replacement for currently used PEDOT: PSS materials.

According to Shawn Williams, Plextronics' vice president of technology, Our company has added significant in-house capabilities to allow scale-up for our new Plexcore ® OC as a result of our collaboration with USDC. Also, we have successfully implemented Plexcore ® OC in partner devices and the material has been tested in newer device architectures. Plextronic’s device design, process technology and Plexcore® branded inks enable the formation of active electrical layers, which are the key drivers of printed electronics.

Entrepreneurial companies like Plextronics are creating new technologies capable of commercial-scale performance and manufacturability, commented Michael Ciesinski, USDC’s CEO. Plextronics’ development marks a significant technology milestone for the rapidly evolving flexible and printed electronics industry. USDC leverages the results of its programs by including member companies in the testing and validation of new developments.

Plextronics has achieved very impressive results from the competitive contract with USDC, U.S. Congressman Jason Altmire (PA-04) said.  Plextronics is a great example of how the high - tech companies taking root across our region are helping to make western Pennsylvania a center for technological innovation.

The companies behind the OLLA project (Philips, OSRAM, Siemens, Novaled and Franhofer IPMS) agreed to fund another OLED lighting project - the OLED100.eu, a follow-up project.

The new project will start on September 2008, for 3 years. The budget is $30 million, $20 million out of which will come from the EU.

Although ink-jet (Sumitomo Chemical, Sumation, CDT, etc.), continuous spray (DuPont, Dainippon Screen), roll printing (LG Display, demonstrated for TFT backplanes), and roll-to-roll printing (GE) have gotten most of the attention, there is another, time-tested solution process: slot-coating or extrusion coating, which has been used to apply photoresist, among other things, for decades.

Greg Gibson, CTO of NexTech FAS indicated that the commercial use of slot coating to apply some of the functional coatings used in OLED displays is closer than I would have thought. (NexTech FAS is the operating company for the process equipment companies NexTech Solutions and FAS Holdings Group, which are in the process of merging.)

Slot coaters put down an unpatterned layer of material, so their most obvious application is for OLED lighting and for the unpatterned layers in an OLED display, such as the hole injection layer (HIL) and the electronic transport layer (ETL). Although patterning of multiple organic layers, such as would be required for an RGB display, is difficult, development work is continuing, Gibson said. And patterning of a single layer, as would be required for a color-by-white or monochrome display, is relatively straightforward.

Displays incorporating HIL, ETL, and/or emitting layers applied with slot coaters are likely to appear on the market in 2010, Gibson said. Which layers exactly? Products will incorporate at least two of the three, Gibson answered.

HILs and ETLs are usually apply by thin-film deposition and are very thin. Can slot coaters apply layers that thin? "Our development is to slot-coat very thin layers, and it has taken a combination of equipment and material advancements," Gibson said. "There is a low solids concentration in the wet film, which is fairly thin itself, and then it dries to a thickness of 100 to 200 nm. Although it’s hard to make a direct comparison, that’s in the general range of thin-film deposition. The materials are somewhat different than ink-jet materials because they need to be formulated specifically for slot-coating solution processing."

At the end of the project period, the OLLA project consortium presents its final milestone: the basic technology for a white OLED light source, with an efficacy of 50.7 lumens per watt at an initial brightness of 1.000 cd/m² based on the Novaled PIN OLED technology. The OLLA project is a joint basic research consortium, headed by Philips Lighting.

The OLED technology is generating a novel and very attractive class of solid-state light sources, which are flat, thin, and very lightweight. Due to its freedom of design, OLED lighting technology offers many possibilities for new lighting applications achieving substantial energy savings. Within OLLA 24 partners of 8 European countries have been working closely together developing OLED technology for lighting purposes with the goal to reach an efficacy of 50 lumens per watt combined with a lifetime of over 10.000 hours at 1.000 cd/m2 initial brightness.

Philips Research and Novaled, together with the partners reached the project targets in efficacy, color rendering and brightness. The lifetime of the Novaled device even exceeded the promised value by one order of magnitude.

The Novaled PIN technology has the potential to further improve the power efficiency. It’s in line with the technology roadmap that in the near future some 100 lm/W OLEDs will be achievable, adds Dr. Martin Vehse from Novaled.

Collecting all light of the device in a laboratory set-up with a macro extractor, we measure even more than 80 lumens per Watt, comments Dr. Volker van Elsbergen,
Philips Research, the achievement. "This shows that one of the keys to higher efficiencies will be better light outcoupling technologies. \

Besides the record values listed above, the OLLA project delivered the first large sized ITO-free OLEDs, the first large-area printed OLEDs and several ICT demonstrators. All demonstrators were on show last Thursday on a public event in Eindhoven.

Philips, Osram Opto Semiconductors, Siemens, Novaled and Fraunhofer IPMS will continue the development of OLED lighting technology in a follow-up project. Within this new OLED100.eu project, the efficiency, lifetime and size of OLEDs will further increased.

Universal Display Corporation today announced that the company has successfully demonstrated a record-breaking white OLED with a power efficacy of 102 lumens per watt (lm/W) at 1000 cd/m2 using its proprietary, high-efficiency phosphorescent OLED technology.

Just last month at the Society for Information Display Symposium, Universal Display announced a new record of 72 lm/W. Since then, Universal Display has continued to make significant advances in this area achieving yet another major milestone toward commercialization. The milestone also demonstrates the potential of white OLEDs to offer significant energy savings and environmental benefits to end users around the world. For the first time, white OLEDs have surpassed the power efficacy of the two incumbent indoor lighting technologies - incandescent bulbs are less than 15 lm/W and most fluorescent lamps are 60 - 90 lm/W.

Funded in part by the U.S. Department of Energy (DOE) through its Solid-State Lighting initiative, Universal Display’s 102 lm/W milestone is a significant achievement toward the DOE's roadmap goal of a 150 lm/W commercial OLED light source by 2015.

This WOLED light source also offers a pleasing white emission with a color rendering index (CRI) of 70 and a coordinated color temperature (CCT) of 3900 Kelvin. This all-PHOLED structure uses complementary materials from Universal Display's collaboration partners at LG Chem and Nippon Steel Chemical Company.

Through the use of Universal Display’s PHOLED technology, power-efficient white OLEDs have the potential to reduce energy consumption dramatically and to lower the amount of by-product heat, which creates additional energy and environmental burdens. White OLEDs are also environmentally benign, especially compared to mercury-containing fluorescent lamps and newer compact fluorescent lamps (CFLs). It has been estimated that white OLEDs could worldwide save well over $20 billion in electric costs and over 9 million metric tonnes of carbon emissions from the U.S. alone by 2016.

The final symposium of the OLLA OLED lighting project took place on the High Tech Campus in Eindhoven Netherlands 12.6.08 with about 80 attending the exhibition and about 60 attending the half day conference. The objective is to start the work that will lead to replacement of many of the "6 billion lights that the world buys every year". Presentations from OLLA, Siemens, Novaled, Fraunhofer IPMS, Philips Lighting OLED Development and Royal Philips Electronics and the exhibition alongside revealed that the objectives had been met or exceeded. These objectives embraced laboratory demonstration of sharply improved life for 1000 cd/m2 emission and larger panel size etc, compared to what was available when the project was conceived five years ago.

Polymer OLEDs, despite being printable, were bypassed early on to concentrate on glass sandwiches of small molecule OLEDs. Here, phosphorescent layers exhibited poor life so the long life Novaled PIN OLED construction was favored. All this had echoes of Philips earlier abandoning P-OLEDs on the same campus.