Chiral multiple-resonance thermally activated delayed fluorescence materials based on chiral spiro-axis skeleton for efficient circularly polarized electroluminescence  

作　　者：Shi-Quan Song Xiao Han Zhong-Zhong Huo Ching-Fai Yip Xian-Fang Hong Meng-Ning Ding You-Xuan Zheng 

机构地区：[1]State Key Laboratory of Coordination Chemistry,Jiangsu Key Laboratory of Advanced Organic Materials,School of Chemistry and Chemical Engineering,Nanjing University,Nanjing 210023,China [2]Key Laboratory of Mesoscopic Chemistry of Ministry of Education,School of Chemistry and Chemical Engineering,Nanjing University,Nanjing 210023,China

出　　处：《Science China Chemistry》2024年第7期2257-2264,共8页中国科学（化学英文版）

基　　金：supported by the National Natural Science Foundation of China(92256304,U23A20593)。

摘　　要：Chiral luminescence materials have potential applications in the field of three-dimensional displays due to their circularly polarized luminescence(CPL)characteristics.However,the further development of circularly polarized organic light-emitting diodes(CP-OLEDs)needs to meet the requirements of high efficiency,high color purity,low cost,and high dissymmetry factor(gPLor gEL),chiral multiple resonance thermally activated delayed fluorescence(MR-TADF)materials are considered as candidates in these aspects.Herein,based on a pair of chiral spirofluorene precursors,two pairs of high-performance chiral MR-TADF emitters((R/S)-p-Spiro-DtBuCzB and(R/S)-m-Spiro-DtBuCzB)are developed,which exhibit strong emissions peaking at 491 and 502 nm in toluene with full-width at half-maximum values of 25 and 33 nm,respectively.In addition,small singlet–triplet energy gaps of 0.15 and 0.10 eV with high absolute photoluminescence efficiencies of 95.0%and 96.7%are observed for p-Spiro-DtBuCzB and m-Spiro-DtBuCzB molecules,respectively.OLEDs based on p-Spiro-DtBuCzB and m-Spiro-DtBuCzB display high maximum external quantum efficiencies of 29.6%and 33.8%,respectively.Most importantly,CP-OLEDs present symmetric circularly polarized electroluminescence spectra with|gEL|factors of 3.36×10^(-4)and 7.66×10^(-4)for devices based on(R/S)-p-Spiro-DtBuCzB and(R/S)-m-Spiro-DtBuCzB enantiomers,respectively.

关 键 词：chiral spiro-axis skeleton-based material multiple resonance thermally activated delayed fluorescence circularly polarized electroluminescence dissymmetry factor external quantum efficiency 

分 类 号：TB34[一般工业技术—材料科学与工程] TN383.1[电子电信—物理电子学]