Technical / Research - Page 124

CDT announced today that it has acquired an important portfolio of patent rights from Maxdem Inc. The portfolio includes five US patent applications and their foreign equivalents relating to new light emitting polymer compositions and applications. The deal also includes a license to a large number of patents / applications relating to polyphenylene polymers and other polymer compositions and purification methods. These are expected to be useful in future materials improvements.

Included in the acquisition from Maxdem is a patent application for the invention of phosphorescent compositions containing a critical class of polymer materials in combination with metals / metal ions. CDT believes this provides a fundamental position in the use of conjugated polymers to achieve high efficiency phosphorescent emission in solution processable devices, whether for ink jet printing or any other means of solution processing.

During a session at the Flexible Display Conference here earlier this week, a presentation updating the cost model in roll-to-roll manufacturing painted a less-than-glowing picture of the technique. Presented by consulting firm Abbie Gregg Inc. (Tempe, Ariz.), the study concluded that a combination of high costs and poor availability of production tools are hindering the adoption of roll-to-roll manufacturing.

The study found that the tooling cost of setting an active-matrix flexible organic light-emitting diode (OLED) substrate line amounted to roughly $177 per square foot. The cost of tooling a passive-matrix polymer light-emitting diode (PLED) line is far less, at $45 per square foot.

Update: In March 2011, we posted a follow-up interview with Andy, updating us on Plextronics' business and technology.

OLED-Info.com recently had the opportunity to interview Andy Hannah, the CEO and President of Plextronics. Plextronics was founded in 2002, as a spin-out from Carnegie Mellon University, and is developing critical technology that enables broad market commercialization of organic electronic devices. Such devices include plastic chips, polymer solar cells and organic lights and sensors.

Q: You have developed an optimized hole injection layer for PLED devices. Can you explain that?

The hole injection layer or HIL functions as a gatekeeper that balances the flow of electricity into the OLED, improving the efficiency of generated light, and smoothing out any rough electrodes that would otherwise cause rapid device failure. Plextronics has developed Plexcore HIL, a non-acidic, solvent-based ink that when printed using spin-cast or inkjet techniques form carefully tuned thin-films that function as the HIL.

In the paper titled Full Color 100 dpi AMOLED Displays on Flexible Stainless Steel Substrates, Dr. Anna Chwang will highlight the performance characteristics of a novel flexible, full-color AMOLED display prototype that is based on the Company’s proprietary phosphorescent OLED (PHOLED™), top-emitting OLED (TOLED®) and flexible OLED (FOLED®) technologies. The full-color AMOLED prototype also uses LTPS TFT backplanes designed and fabricated by PARC, a subsidiary of Xerox Corporation, and was encapsulated by Vitex Systems.

The four-inch diagonal display can portray a variety of images, including full-motion video. This advance is significant in proving the fundamental feasibility of the Company’s approach and also clearly demonstrates several key performance advantages. The display (without external drive electronics and package) is approximately 0.1 mm thick and weighs a mere 6 grams. The comparable glass-based LCD would be approximately 1.0-1.5 mm thick and weigh 20-30 grams. Research and development activities are continuing in a number of areas including enhanced display flexibility, defect elimination and enhanced electronics capabilities

GE Global Research is presenting details on its successful development of a substrate system for flexible OLEDs at the Flexible Displays & Microelectronics Conference, Feb. 6-9 in Phoenix, Ariz. The system features a developmental high-temperature Lexan polycarbonate (PC) film from GE - Plastics combined with a transparent, ultra-high-barrier coating to help protect the OLED device against oxygen and moisture.

This research, jointly funded by the U.S. Display Consortium (USDC) and GE, is designed to address the critical need for plastic substrates that can enable cost-effective, lightweight, flexible organic displays. Min Yan, GE materials scientist, will give a presentation on the new substrate system, which is currently being produced in batch mode and will ultimately be moved to a roll-to-roll process for cost efficiency. In addition, GE - Plastics is featuring a variety of plastic films for electrical/electronic display applications during the exhibition.

UDC announced today that it has been awarded a significant patent covering ink-jet printing of phosphorescent OLED displays, US Patent No. 6,982,179, titled "Structure and Method of Fabricating Organic Devices".

"This PHOLED ink-jet printing patent provides another option for OLED manufacturers in choosing how to produce displays using our proprietary phosphorescent OLED technology," said Steven V. Abramson, President and Chief Operating Officer of Universal Display Corporation. "The patent is a further demonstration of the breadth and depth of Universal Display's PHOLED technology, which is widely recognized as critical for OLED displays - from small, where power efficiency is critical, to large, where power efficiency equates to less heat generation."

Universal Display Corporation announced it has been awarded a $69,999 Small Business Innovation Research (SBIR) Phase I contract by the U.S. Army Research Laboratories (ARL), for a program entitled Flexible and Conformal Environmental Barrier Technology for Displays.

During this Phase I program, Universal Display will integrate a novel low-temperature plasma enhanced chemical vapor deposition (PECVD) process coating technology with its proprietary FOLED®, TOLED® and PHOLED™ technologies. The PECVD process is based on pioneering research at Princeton University, which is believed to enable the deposition of flexible and protective films onto the top surface in an OLED without causing damage to the OLED. The end result will be the demonstration of a flexible OLED display prototype built on a stainless steel substrate. This research is an important element toward the Company’s goal of developing a rugged, long-lived, thin and lightweight flexible OLED display technology for both military and commercial applications.

Sidney Rosenblatt, Chief Financial Officer of Universal Display Corporation, in a presentation titled "Changing the Display Landscape through Phosphorescent OLEDs," will announce the achievement of key technological milestones in the Company's development of blue PHOLED materials and technology. Universal Display's new blue PHOLED system with sky blue color of CIE (0.16, 0.37) now offers luminous efficiency of 20 candelas per ampere (cd/A) and 100,000 hours of operating lifetime at 200 candelas per square meter (cd/m2). This follows the Company's breakthrough announcement in June, 2005 of a sky blue PHOLED with over 15,000 hours at 200 cd/m2. That was the first significant blue PHOLED to break through the 1,000 hour lifetime barrier.

The Company has also made significant progress in the demonstration of deeper blue performance. Mr. Rosenblatt will present a proprietary new blue PHOLED with CIE (0.16, 0.29), excellent luminous efficiency of 21 cd/A and over 17,500 hours of operating lifetime at 200 cd/m2. This corresponds to over 3,000 hours at 500 cd/m2, a target luminance for commercial applications.

UDC today announced it has been awarded a two-year, $730,000 Small Business Innovation Research (SBIR) Phase II contract by the U.S. Army Communication Electronics Research and Development Engineering Center (CERDEC).

Under the terms of the contract, Universal Display will develop and demonstrate an active-matrix, flexible PHOLED display containing infrared (IR)-emitting PHOLED pixels in addition to visible spectrum PHOLED pixels. The Company's infrared (IR)-emission OLED technology is being designed to be seen only through night vision goggles so to avoid visual detection in darkness. By combining IR-emitting and visible PHOLED pixels into one display, the Company is creating a novel display architecture to meet the Army's requirement for a single, high-information-content display that works in high, low and no light conditions.

The active-matrix PHOLED display, also enabled by Universal Display's proprietary flexible OLED and top-emission OLED technologies, will be built on flexible metal foil using poly-silicon backplane technology from Palo Alto Research Center (PARC) to provide flexibility, light weight and ruggedness. As a continuation from the Phase I program, University of Southern California will develop novel PHOLED materials for evaluation in the prototype.

Scientists at the Fraunhofer Institute for Applied Polymer Research (IAP) in Potsdam have succeeded in constructing transparent OLED displays using light-emitting polymers. Their brightness, operating life time and efficiency are so high that the first commercial applications can be envisaged. We achieved this result by using a new type of metal electrode to supply the polymer film with electric current, reports Armin Wedel of the IAP.

The clue of the transparency lies in its physical properties. Earlier metal oxide coatings were too thick to allow enough light to pass through. But making them thinner reduces their conductivity and hence the luminescence and operating life time of the display.