Osram has achieved a record 25 lm/W efficacy for a white-emitting polymer-OLED device, as well as developing the first tunable polymer-OLED light source.
The 25 lm/W cool-white-emitting device utilizes a solution-processable, phosphorescent, blue-emitting device in conjunction with an external inorganic phosphor layer. The blue device, with an efficacy of 14 lm/W, was made by embedding an efficient phosphorescent blue emitter in a polymer host.
The Osram team has also achieved and demonstrated a 20 lm/W phosphorescent device based on a white-emitting polymer blend. This device employs no external phosphors, and the white emission comes directly from the phosphorescent polymer.
This high-performance, organic light source provides the basis for Osram's further OLED lighting-application development. Next steps include the company's efforts to transfer this technology into large-area light tiles. This task has inherent challenges, which include developing robust materials to increase product lifetime and developing lighting-panel uniformity.
To overcome these hurdles, continuous work is required to integrate a phosphorescent-emitting blend material into a single polymer, thus endeavoring to reduce the operating voltage through cathode engineering.
The tunable light source is the industry's first OLED demonstration based on three separate, printable polymer inks emitting in the red, green and blue portion of the spectrum. Ink-jet printing was utilized to pattern the small three-color segments. The product's unique driver circuitry enables users to regulate color from dark blue to white, or any color combination the user prefers, offering freedom of design and innovative illumination solutions. Such printable OLED technology offers the advantage of large-size scalability without losses in key optical and electrical properties.
The results were achieved as part of Osram Opto Semiconductors' white OLED project, funded by a $4.65 million grant from the US Department of Energy (DOE).
Samsung SDI to invest $450 million in AM-OLEDs
Samsung SDI has announced a plan to invest 465.5 billion won ($450 million dollars) in next-generation OLED production lines.
South Korea's largest display screen manufacturer will invest the money in the production of active-matrix (AM) OLED panels, and expects to have the infrastructure in place by the second half of 2006. Around 20 million units will be produced in 2007, rising to 50 million by 2008.
The company plans to produce a range of sizes, including 2-inch, 8.4-inch, 15.1-inch, and 15.5-inch screens.
OLEDs have the theoretical potential to replace LCDs, CRTs and other display technologies, thanks to their greater efficiency, easier production, more physical flexibility and lower cost. To date, however, problems with device lifetime, chemistry and production have limited their use to mobile devices and backlights.
Samsung makes its OLED displays using a transfer technology in which a pattern of plastic pixels is printed on the screen by scanning a laser across a set of organic films.
Samsung's basic OLED technology was licensed from Kodak and developed in conjunction with NEC, which sold its stake in the joint venture to Samsung at the beginning of 2004.
MP3 players set to become top application for OLEDs
MP3 players are poised to overtake mobile phone handset sub-displays as the leading application for OLED displays in 2006.
Currently, handset sub-displays account for half of all OLED panel shipments, with MP3 players accounting for another 45%. Displays used in cars are a distant third.
Global MP3 player shipments are expected to reach 90 million units in 2006, and 26% of these will have OLED displays. Other players either have no display or employ LCD displays with LED backlights.
