Novel thioxanthone host material with thermally activated delayed fluorescence for reduced efficiency roll-off of phosphorescent OLEDs  

作　　者：Hui Wang Xiaopeng Lv Lingqiang Meng Xiaofang Wei Ying Wang Pengfei Wang 

机构地区：[1]Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, College of Chemistry & Materials Science, Northwest University, Xi'an 710127, China [2]Key Laboratory of Photochemical Conversion and Optoelectrontc Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China [3]Institute of Functional Nano and Soft Materials, Soochow University, Suzhou 215123, China

出　　处：《Chinese Chemical Letters》2018年第3期471-474,共4页中国化学快报（英文版）

基　　金：supported by National Natural Science Foundation of China(No. 61605158);the Science and TechnologyDepartment of Shaanxi Province(No. 2016JQ2028);the Education Department of Shaanxi Province(No. 16JK1790)

摘　　要：2,7-Di（9,9-dimethyl-9H-fluoren-l-yl）-9H-thioxanthen-9-one （DMBFTX） with thermally activated delayed fluorescence （TADF） was well designed and synthesized. The phosphorescent organic lightemitting device （PHOLED） based on this novel TADF host material displays a stable red phosphorescence region, a peak external quantum efficiency （EQE） value of 12.9% and a low EQE roll-off of 38.8%at a luminance of 10000 cd/m2, which is benefited from the reverse intersystem crossing （RISC） of TADF host and less populated triplet exitons. Notably, the red device based on the TADF host DMBFrX exhibits superior electroluminescence performance and reduced efficiency roll-offcompared with the one hosted by commercially available host 1,3-bis（9-carbazolyl）benzene （mCP）, illustrating the high potential of employing the TADF host material with small energy gap to reduce efficiency roll-off in PHOLED.2,7-Di（9,9-dimethyl-9H-fluoren-l-yl）-9H-thioxanthen-9-one （DMBFTX） with thermally activated delayed fluorescence （TADF） was well designed and synthesized. The phosphorescent organic lightemitting device （PHOLED） based on this novel TADF host material displays a stable red phosphorescence region, a peak external quantum efficiency （EQE） value of 12.9% and a low EQE roll-off of 38.8%at a luminance of 10000 cd/m2, which is benefited from the reverse intersystem crossing （RISC） of TADF host and less populated triplet exitons. Notably, the red device based on the TADF host DMBFrX exhibits superior electroluminescence performance and reduced efficiency roll-offcompared with the one hosted by commercially available host 1,3-bis（9-carbazolyl）benzene （mCP）, illustrating the high potential of employing the TADF host material with small energy gap to reduce efficiency roll-off in PHOLED.

关 键 词：Low efficiency roll-off Thermally activated delayed fluorescence Small energy gap Reverse intersystem crossing Phosphorescent OLEDs 

分 类 号：TN383.1[电子电信—物理电子学]