Taiwan's ITRI research institute developed a long-lasting OLED blue emitter. The researchers used a green phosphorescent emitter with a new double metal structure - that emits a blue light. The so-called Plasmon-Coupled Organic Light Emitting Diode (PCOLED) structure's lasts 27 times as long as a blue fluorescent emitter.

ITRI PCOLED diagram

The researchers explain that a regular green phosphorescent emitter always emits a very weak emission. By using the double-metal structure, more plasmons are generated which means a larger blue emission. This is not an up-conversion process - but merely a change in conditions within the green material. This condition was actually discovered by accident.

PCOLED lifetime comparison table

ITRI already developed 10x10 cm and 15x15 cm OLED prototypes based on this new structure, and they have started to collaborate with Taiwan-based WiseChip to commercialize this technology - first in a PMOLED display. Wisechip already converted an existing R&D line to make PCOLED displays, but it will take about 1-2 years before they can make such displays commercially.

The current technology uses evaporable OLED emitters in a vacuum-deposition process, but the researchers have also started to think about solution-based emitters, and hope to start developing soluble PCOLED emitters within a few years.

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