A meta-linkage strategy towards high-performance hosts for efficient blue thermally activated delayed fluorescence OLEDs. (9th February 2022)

• Record Type: Journal Article
• Authors: Tao, Xiao-Dong; Wei, Zhuangzhuang; Meng, Lingyi; Chen, Xu-Lin; Yang, Mingxue; Jing, Yan-Yun; Zhang, Dong-Hai; Lu, Can-Zhong
• Is Part Of: Materials chemistry frontiers. Volume 6:Number 6(2022)
• Page Start: 748
• Page End: 756
• Publication Date: 2022-02-09
• Subjects: Materials science -- Periodicals; Chemistry -- Periodicals; 540
• DOI: 10.1039/d1qm01660a
• Languages: English
• ISSNs: 2052-1529

Abstract

Abstract : The development of high-performance host materials for blue thermally activated delayed fluorescence (TADF) emitters is crucial for realizing efficient blue organic light-emitting diodes (OLEDs). Abstract : The development of high-performance host materials for blue thermally activated delayed fluorescence (TADF) emitters is crucial for realizing efficient blue organic light-emitting diodes (OLEDs). Herein, two star-shaped host materials, tris(3-(diphenylphosphanyl oxide)phenyl)phosphane oxide (m4PO ) and tris(3-(carbazole)phenyl)phosphane oxide (m3CzPO ), containing a triphenylphosphine oxide (TPPO) core and three meta -substituted diphenylphosphine oxide or carbazolyl groups, are designed and synthesized. The comparative study reveals that the meta -linkage strategy significantly improves the performances of the hosts. The two hosts show superhigh triplet energies of over 3.1 eV, along with high thermal stability, good carrier-transporting capability, and high film quality, which establish the basis for being potentially ideal hosts for blue TADF emitters. Based on a conventional blue TADF emitter bis[4-(9, 9-dimethyl-9, 10-dihydroacridine)phenyl]sulfone (DMAC-DPS), the blue TADF-OLEDs realize high performances with maximum external quantum efficiencies (EQEs) beyond 20%, maximum power efficiencies (PEs) over 40 lm W −1, a low turn-on voltage of 2.8 V, and a high luminance of up to 5170 nits.