26 November 2018

The PHEBE project finished at the end of July 2018 and recently passed its final review with the European Commission.

This gives the PHEBE consortium cause to pause and reflect on the main results and conclusions of the project.

PHEBE was a 3 ½ year project funded by the EU’s Horizon 2020 programme. The overall objective was to develop innovative blue emitters for white organic light emitting diodes (OLEDs). This was so that the cost and environmental impact of OLED lighting could be reduced.

During the project, the consortium was able to produce blue emitters based on phenylcarbazole organic material that demonstrated thermally activated delayed fluorescence (TADF) and these blue emitters had good external quantum efficiency of up to 18%.

However, the 50% lifetime for these blue emitters was very short – just 2 hours – so the consortium is still quite a way off from having new material that can be used commercially for OLED lighting.

The consortium believes the emitter’s lifetime issue is dependent on two factors:
  • The host material used together with the emitter material needs to be very carefully selected. Previously, it was thought that the lifetime was independent of the host.
  • The synthesised organic material used for the emitter needs to be extremely pure, as close to 100% as possible.
Although PHEBE did not meet its end objective, it generated new knowledge and advanced the state-of-the-art of TADF materials. The consortium published over 25 journal articles – including two in Nature Communications - and filed patents for three new families of organic materials.