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Iridium(III) Carbene Phosphors with Fast Radiative Transitions for Blue Organic Light Emitting Diodes and Hyperphosphorescence
Author(s) -
Zheng Zhong,
Wang Lu,
Xin Yangyang,
Wang Qi,
Hong Xiangchen,
Zhang Yuewei,
Yiu ShekMan,
Zhou Fan,
Yan Jie,
Zhang Dongdong,
Duan Lian,
Chi Yun
Publication year - 2025
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.202311692
Subject(s) - oled , phosphor , quantum efficiency , iridium , quantum yield , full width at half maximum , materials science , carbene , photoluminescence , common emitter , radiative transfer , analytical chemistry (journal) , optoelectronics , fluorescence , physics , optics , chemistry , nanotechnology , organic chemistry , layer (electronics) , catalysis
Abstract It is envisioned that the efficient and stable blue OLED phosphors can be synthesized using Ir(III) complexes with electron‐deficient carbene cyclometalates. Therefore, three facially coordinated Ir(III) phosphors f ‐ct7a‐ c bearing isomeric purinylidene chelates are obtained. They possess three, two, and one 4‐ t ‐butylphenyl cyclometalate together with the same number of N‐phenyl appendage on carbene fragments, and exhibit photoluminescence centered ( λ max ) at 452‒461 nm, fast radiative rate constants ( k r ) of 7.5–11.3 × 10 5 s ‒1 , and high quantum yield (PLQY) up to 80% in degassed toluene at RT. Representative OLED based on f ‐ct7c gives maximum external quantum efficiency (EQE max ) of 26.6%, CIE ( x , y ) of 0.16, 0.15, and low roll‐off with EQE of 22.3% at 1000 cd m ‒2 . Furthermore, they can be utilized to sensitize a deep blue multiple resonance thermally activated delay fluorescence emitter (MR‐TADF), i.e., t ‐DABNA. The corresponding hyper‐OLED device based on alternative f ‐ct7b realizes an EQE max of 36.1%, CIE ( x , y ) of 0.14, 0.09, and full width at half maximum (FWHM) of 26.5 nm. To the understanding, this is the first report on concurrent achieving both the high EQE and small CIE y value for Ir(III)‐based phosphors.