Phosphorescent

Second-generation OLED phosphorescence emission features an internal quantum efficiency of almost 100% - which would normally mean you cannot get more efficient than that.

As Kyulux explains in a recent post, though, phosphorescent suffers from a wide emission spectrum. In order to achieve a good color gamut (for which as narrow-spectrum emission as possible is best) display makers have to filter out the "tail" of the emission. This results in reduced brightness and efficiency.

In 2016, Researchers from Japan's Semiconductor Energy Laboratory (SEL) announced a new OLED device architecture, called ExTET ('exciplex–triplet energy transfer'), that can increase the performance of OLED devices. The technology was applied for a patent in 2011.

The ExTET technology, which is a modification of the host material and the EML layer in phosphorescent OLED devices, have since been introduced to commercial AMOLED panels, increasing the efficiency and lifetime of the materials, while also lowering the drive voltage.

Universal Display announced that Tianma Micro-electronics has extended its long-term OLED material supply and license agreement. UDC will continue to supply Tianma with its phosphorescent OLED materials and technologies.

UDC did not disclose any more details or financial terms. The original agreement between Tianma and UDC was signed in 2016.

Hyperfluoresence emitter system developer Kyulux announced that its green material is getting close to commercialization. The company is now working closely with OLED makers, preparing for early adoption.

Kyulux says that its green emitter has not only met the required performance of OLED panel makers, in terms of efficiency, lifetime and driving voltage - but has actually surpassed the performance of green phosphorescent emitters in top emission devices. The green HF device achieves higher current efficiency, longer lifetime and offers a narrow emission spectrum and can thus enable better chromaticity.