基于1,3,6,8-四甲基咔唑热活化延迟荧光材料的合成及发光性质

Synthesis and luminescent properties of 1,3,6,8-tetramethylcarbazole based thermally activated delayed fluorescence materials

以1,3,6,8-四甲基咔唑(TMCz)为给体,1,3,4-噁二唑(OXD)和1,3,4-噻二唑(THD)分别为受体,设计合成了两例发光材料2,5-双{4-[9-(1,3,6,8-四甲基咔唑基)]-苯基}-1,3,4-噁二唑(TMCz-OXD)和2,5-双{4-[9-(1,3,6,8-四甲基咔唑基)]-苯基}-1,3,4-噻二唑(TMCz-THD)。利用电化学分析仪、UV-Vis分光光度计、稳态/瞬态荧光光谱仪对其电化学及光物理性质进行了测试。通过光谱仪和电源测量仪对基于TMCz-OXD和TMCz-THD的有机发光二极管进行了电致发光性质的测试。结果表明,TMCz的1,8位甲基的空间位阻能有效增大给受体之间的二面角(86°),促进最高占据分子轨道和最低未占据分子轨道的分离,实现热活化延迟荧光性质。TMCz-OXD和TMCz-THD的掺杂膜均表现出热活化延迟荧光性质,相应电致发光的最大外量子效率分别为6.5%和6.4%。

Two luminescent materials,2,5-bis{4-[9-(1,3,6,8-tetramethylcarbazolyl)]-phenyl}-1,3,4-oxadiazole(TMCz-OXD)and 2,5-bis{4-[9-(1,3,6,8-tetramethylcarbazolyl)]-phenyl}-1,3,4-thiadiazole(TMCz-THD)were designed and synthesized with 1,3,6,8-tetramethylcarbazole(TMCz)as donor and 1,3,4-oxadiazole(OXD)and 1,3,4-thiadiazole(THD)as acceptor,respectively.Their electrochemical and photophysical properties were measured by electrochemical analyzer,UV-Vis spectrophotometer and steady-state/transient fluorescence spectrometer.The electroluminescence properties of organic light-emitting diodes(OLEDs)based on TMCzOXD and TMCz-THD were tested by spectrometers and source-measure units.The results showed the steric hindrance of the 1,8 methyl groups of TMCz could effectively increase the dihedral angle(86°)between donor and acceptor,promote the separation of the highest occupied molecular orbital and the lowest unoccupied molecular orbital,and achieve the thermally activated delayed fluorescence properties.Both doped films of TMCz-OXD and TMCz-THD exhibited thermally activated delayed fluorescence properties.And the maximum external quantum efficiency of corresponding electroluminescence was 6.5%and 6.4%,respectively.