Solution‐processed high‐performance organic light‐emitting diodes containing a green‐emitting multiresonant thermally activated delayed fluorescent dendrimer

Abstract

AbstractA multi‐resonance thermally activated delayed fluorescence (MR‐TADF) dendrimer emitter and a related reference MR‐TADF compound were designed, synthesized, and characterized for use as narrowband emitters in solution‐processed OLEDs. The 1 wt% doped films in PMMA film revealed that the compounds MR‐D1 and MR‐D2 showed narrowband green emission at λPL of 490 and 495 nm and with FWHM of 23 and 29 nm, respectively. The 50 wt% doped films in mCP still show narrowband green emission at λPL of 495 and 499 nm and with FWHM of 28 nm for MR‐D1 and MR‐D2, respectively, while conserving the small ΔEST of 0.14 and 0.13 eV, respectively. OLEDs containing an emissive layer consisting of 50 wt% MR‐D1 and MR‐D2 in mCP showed high EQEmax of 27.7% and 21.0%, respectively, and low efficiency roll‐off of 19% and 30% at a luminance of 2000 cd/m−2.