Phosphorescent - Page 22

Novaled announced it has developed a highly power-efficient white OLED structure achieving 60 lm/W at a brightness of 1,000 cd/m² capable of reaching 100,000 hours lifetime (at an initial brightness of 1,000 cd/m²). The new OLED uses red and green phosphorescent materials and a commercially available fluorescent blue material.

Novaled says that a fluorescent blue emitter usually results in much less efficient devices, but their PIN OLED technology and proprietary materials resulted in this highly efficient device. Using this fluorescent materiel has several advantages - good device stability, higher lifetime and it is commercially available. It also enables a broad coverage of the complete visible color range.

Universal Display has quietly released a new PHOLED material performance chart. Their Green-Yellow material now has 1.4 million lifetime hours (LT50), and their Red color offers 900,000 hours. Blue is still very challenging, and their light blue offers only 20,000 hours (LT50). Here's the complete chart:

The company also released some PHOLED material efficiency. Using only red PHOLED (with green and blue fluorescent materials) will result in a display that is about 15% more efficient compared to an LCD (this is the combination Samsung used in their 4.5-Gen AMOLED fab). Adding green color will result in a a display that is 30% more efficient compared to an LCD (this is the combination Samsung is using in their new 5.5-Gen fab). Adding blue will give a 50% more efficient display. UDC says that further enhancements (not specified) can result in a display that is 67% more efficient than an LCD. All these results are based on a 4" display operating at 300 cd/m² showing a video that has 40% pixels on.

BASF and Osram Opto Semiconductors have developed a highly efficient white OLED panel. The efficiency is over 60 lm/w. This development was part of the OPAL project which launched in 2008. Other partners in this project include Aixtron, Philips and Applied Materials.

Following quickly behind the recent announcement of rapid progress in the development of longer lifetime blue light emitting polymers, comes this announcement of similarly impressive progress on red materials.

Data from devices produced using these latest, solution processable, phosphorescent materials show lifetime of 98,900 hours from an initial luminance of 400 cd/m², equivalent to over 1.5 million hours from 100 cd/m².

Cambridge Display Technology (CDT) announces two major milestones in the development of long lifetime, high efficiency light emitting polymers for full color, video capable displays.

A phosphorescent red device has been produced by CDT and Sumitomo Chemical which has a lifetime of half a million hours from an initial luminance of 100cd/m(2); this is a record for lifetime of solution-processable materials of any color. The efficiency is also improved at over 7cd/A. Red efficiency is especially important as this color consumes the largest share of power input in a color device, so improvements in red efficiency have important practical implications.

Cambridge Display Technology (CDT) announced that the EU-funded STEPLED project has concluded - with "outstanding success". The STEPLED project was undertaken with the aims of understanding the science which controls the spin states of polymer-based OLED (PLEDs), critical to developing more power efficient displays.

The STEPLED project focused on establishing high efficiency materials using high singlet-ratio fluorescent polymers, but also worked on soluble phosphorescent emitter. CDT said that STEPLED achieved the production of a standard two-layer device structure with an external quantum efficiency (EQE) of 6%. This has been described as 'outstanding', being almost twice the efficiency of previous materials. The impressive performance was achieved using red emitting polymers, typically the lowest efficiency color in RGB displays.