Multiple-resonance thermally activated delayed emitters through multiple peripheral modulation to enable efficient blue OLEDs at high doping levels  

作　　者：Yuyuan Wang Zhiwei Ma Junrong Pu Danman Guo Gaoyu Li Zhu Chen Shi-Jian Su Huangjun Deng Juan Zhao Zhenguo Chi 

机构地区：[1]PCFM Lab,GD HPPC Lab,Guangdong Engineering Technology Research Center for High-Performance Organic and Polymer Photoelectric Functional Films,State Key Laboratory of Optoelectronic Material and Technologies,School of Chemistry,Sun Yat-sen University,Guangzhou,China [2]State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices,South China University of Technology,Guangzhou,China [3]State Key Laboratory of Optoelectronic Material and Technologies,School of Materials Science and Engineering,Sun Yat-sen University,Guangzhou,China

出　　处：《Aggregate》2024年第5期349-357,共9页聚集体（英文）

基　　金：National Natural Science Foundation of China,Grant/Award Numbers:51733010,52073316;Basic and Applied Basic Research Foundation of Guangdong Province,Grant/Award Numbers:2022B1515020052,2021A1515110119。

摘　　要：Organic light-emitting diodes(OLEDs)based on multiple resonance-thermallyactivated delayedfluorescence(MR-TADF)have the advantages of high excitonutilization and excellent color purity.However,the large conjugated planarity of gen-eral MR-TADF emitters makes them easily aggregate in the form ofπ–πstacking,resulting in aggregation-caused quenching(ACQ)and the formation of excimers,which reduce exciton utilization efficiency and color purity.To address these issues,large shielding units can be incorporated to prevent interchromophore interactions,whereas the majority of reported molecules are limited to blue-green light emis-sions.This work proposes a strategy of incorporating steric hindrance groups atdifferent sites of the B/N core to suppress interactions between chromophore,con-tributing to blue MR-TADF emitters with high photo-luminance quantum yields(PLQYs≥95%)and narrow full width at half maximum(FWHM),and importantly,great suppression of the ACQ effect.Therefore,blue OLEDs achieve high externalquantum efficiencies up to 34.3%and high color purity with FWHM of about 27 nmand CIE around(0.12,0.15),even at a high doping concentration of 20 wt%.

关 键 词：blue emission color purity multiple-resonance organic light-emitting diodes thermally activated delayedfluorescence 

分 类 号：TN312.8[电子电信—物理电子学]