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

本文以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）为受体，设计合成了两例发光材料，即TMCz-OXD和TMCz-THD。利用紫外-可见吸收光谱、发射光谱、电化学分析等手段对其光物理、电化学以及电致发光性质进行了研究。实验表明，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°）。TMCz-OXD和TMCz-THD的掺杂膜中均表现出热活化延迟荧光（TADF）性质，相应电致发光的最大外量子效率（EQE）分别为6.5%和6.4%。TMCz可作为蓝光TADF材料的普适性给体，广泛应用于有机光致/电致发光材料以及有机发光二极管等领域。

Synthesis and luminescent properties of 1,3,6,8-tetramethylcarbazole based TADF materials

Two luminescent materials with 1,3,6,8-tetramethylcarbazole (TMCz) donors and 1,3,4-oxadiazole (OXD) or 1,3,4-thiadiazole (THD) acceptor, namely TMCz-OXD and TMCz-THD, were designed and synthesized. The photophysics, electrochemical properties and electroluminescence were characterized by UV-vis absorption and emission spectroscopy and electrochemical analysis. Experiment results show the steric hindrance caused by two methyl groups on the 1,8 sites of TMCz can effectively increase the dihedral angle (86?) between donor and acceptor. Both doped films of TMCz-OXD and TMCz-THD exhibited thermally activated delayed fluorescence (TADF) character. And the external quantum efficiencies (EQEs) of the corresponding electroluminescence were 6.5% and 6.4%, respectively. As a versatile blue TADF material donor, TMCz can be applied widely in the field of organic light-emitting diode (OLED).