Fluorescent - Page 6

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.

Novaled announced that it has developed a new efficient (36 lm/W) fluorescent white OLED, which the company claims is the world's most power efficient white OLED structure. Novaled used their own proprietary organic materials and a new flat light outcoupling method of extraction and achieved an increase in light emission by more than 80%, with good color rendering. Novaled's new structure also has an improved light angular dependence.

Here's more technical info from Novaled's press release: 

Hodogaya Chemical and Novaled have agreed to offer hole transport materials (HTM) for Novaled PIN-OLED structures. Hodogaya has exclusively developed specific HTM for Novaled fitting very well with the Novaled PIN OLED structures. As a first result Novaled is enhancing its material offer with an additional hole transport material called NHT18.

The new NHT18 has a similar behavior in OLEDs like NPB, but provides additional advantages to OLED manufacturers. For example, the Tg of NHT18 is above 130C and thus gives a high temperature stability in OLED devices. The current efficiency in today's fluorescent blue emitting PIN OLEDs is 10% higher.

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.