Application of X-ray Free Electron Lasers (XFELs) to study OLED materials

Within this project we investigate Cu-based metalloorganic materials which are promising for applications in Organic Light Emitting Diodes. Their high efficiency is probably due to temperature-activated delayed fluorescence (TADF) effect. The goal of our investigation is to catch short lived singlet excited states and to determine its local atomic and electronic structure. This singlet state is short lived (picoseconds), but is relevant for emissive properties of the material also in the microsecond time range.

We have received beamtime at European X-ray Free Electron Laser. We also recently performed first pilot pump-probe experiment at Alvra beamline of SwissFEL.

Pilot experiment at Alvra beamline of SwissFEL . View inside the chamber. Green fluorescence from Cu-based OLED complexes excited with UV light