Sulfone-Incorporated Multi-Resonance TADF Emitter for High-Performance Narrowband Blue OLEDs with EQE of 32

摘要

The blue multi-resonance thermally activated delayed fluorescence materials,simultaneously realizing narrow full-width at half-maximum, high externalquantum efficiency (EQE), and low efficiency roll-off, remains a formidablechallenge. Herein, three novel emitters, namely PTZBN1, PTZBN2, andPTZBN3, are designed by gradual peripheral modification in boron/nitrogen(B/N) embedded polycyclic skeleton, which exhibit progressively hypsochromic-shifted emission from 490 nm (PTZBN1) to 468 nm (PTZBN3) withphotoluminescence quantum yields up to 98. In particular, the incorporationof sulfone unit in the boron/nitrogen (B/N) embedded polycyclic skeleton providesa simple but effective tactic for narrowband blue emission. The organiclight-emitting diodes based on PTZBN2 achieve one of the-state-of-the-artEQEs of 34.8 with electroluminescence (EL) peak at 478 nm. Impressively,PTZBN3-based device exhibits not only a high maximum EQE of 32.0 withEL peak at 468 nm, but also low efficiency roll-off.