Saved in:
| Main Authors: | , , , , , , |
|---|---|
| Format: | Preprint |
| Published: |
2026
|
| Subjects: | |
| Online Access: | https://arxiv.org/abs/2604.06476 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866914455722393600 |
|---|---|
| author | Soleimani, Mahmoud Bärschneider, Toni Kaden, Felix Tkachov, Roman Schellhammer, Sebastian Reineke, Sebastian Rothe, Carsten |
| author_facet | Soleimani, Mahmoud Bärschneider, Toni Kaden, Felix Tkachov, Roman Schellhammer, Sebastian Reineke, Sebastian Rothe, Carsten |
| contents | The realization of blue electroluminescence with high efficiency and lifetime remains a long-standing hurdle for OLED technology to overcome. Divalent Europium [Europium(II)] complexes offer a fundamentally distinct pathway toward this goal, as their atomic 4f-5d transitions yield single-Gaussian, spectrally pure emission with theoretical 100% exciton utilization and no involvement of fragile organic bonds in the emissive process. However, their true potential has never been fully demonstrated before. In this work, we design a rigid aza-crown europium(II) complex (Eu5NHCrown) that achieves near-unity photoluminescence quantum yield with bright, pure-blue emission. The complex sublimes without decomposition and can be vacuum-deposited into a bottom-emitting, single-host OLED architecture, delivering an external quantum efficiency (EQE) of 20.7% with minimal roll-off (19.3% at 1000 cd m-2 ) and a narrowband electroluminescence with CIE coordinates of (0.12, 0.25). These results reveal the true potential of Eu(II) 4f-5d transitions for high-efficiency blue OLEDs, establishing a molecular design concept that bridges atomic-transition efficiency with the processability of organic materials. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2604_06476 |
| institution | arXiv |
| publishDate | 2026 |
| record_format | arxiv |
| spellingShingle | Blue organic light-emitting diodes with over 20% external quantum efficiencies based on Europium(II)-emitters Soleimani, Mahmoud Bärschneider, Toni Kaden, Felix Tkachov, Roman Schellhammer, Sebastian Reineke, Sebastian Rothe, Carsten Applied Physics Materials Science The realization of blue electroluminescence with high efficiency and lifetime remains a long-standing hurdle for OLED technology to overcome. Divalent Europium [Europium(II)] complexes offer a fundamentally distinct pathway toward this goal, as their atomic 4f-5d transitions yield single-Gaussian, spectrally pure emission with theoretical 100% exciton utilization and no involvement of fragile organic bonds in the emissive process. However, their true potential has never been fully demonstrated before. In this work, we design a rigid aza-crown europium(II) complex (Eu5NHCrown) that achieves near-unity photoluminescence quantum yield with bright, pure-blue emission. The complex sublimes without decomposition and can be vacuum-deposited into a bottom-emitting, single-host OLED architecture, delivering an external quantum efficiency (EQE) of 20.7% with minimal roll-off (19.3% at 1000 cd m-2 ) and a narrowband electroluminescence with CIE coordinates of (0.12, 0.25). These results reveal the true potential of Eu(II) 4f-5d transitions for high-efficiency blue OLEDs, establishing a molecular design concept that bridges atomic-transition efficiency with the processability of organic materials. |
| title | Blue organic light-emitting diodes with over 20% external quantum efficiencies based on Europium(II)-emitters |
| topic | Applied Physics Materials Science |
| url | https://arxiv.org/abs/2604.06476 |