In this study, three triazatruxene-based molecules Tr-Me, Tr-Ph, and Tr-Tol with methyl, phenyl, and p-tolyl pendant groups, respectively, were intermixed with three acceptors 3P-T2T, 3P-T2P, and 3P-Pyr featuring phenylpyrazole peripherals and triazine, pyrimidine, and pyridine cores, respectively, to generate an array of nine blends to probe the feasibility of formation of an exciplex. The observed red-shifted emission compared to those of pristine donor and acceptor films is a good indication of exciplex formation. The exciplex emissions are mainly modulated by the features of N-heteroarene cores of acceptors, while the HOMOs of the donors are less influenced by the substituents. From the screening of these D:A combinations it was concluded that four exciplex-forming blends composed of Tr-Ph and Tr-Tol as donors and 3P-T2T and 3P-T2P as acceptors exhibit promising properties suitable for OLED applications. Among them, a green device employing a Tr-Tol:3P-T2P blend as the emitting layer performed with the best efficiency with a maximum external quantum efficiency (EQE_max) of up to 12.8%. These new exciplex-forming systems were further explored as cohosts for a newly developed fluorescent emitter (DT)₂BTh2CN. The Tr-Ph:3P-T2P blend was found to serve as the best host to give a deep-red (EL λ_max 671 nm, CIE (0.68, 0.31)) OLED device with an EQE_max of 5.52%. The data extracted from the transient photoluminescent studies shed light on the emission mechanism which is dominated by Förster energy transfer and simultaneously suffers from competing Dexter energy transfer quenching. Our results highlight the feasibility of using triazatruxene as the donor for exciplex formation as well as the tunability of the emission wavelength of exciplex-forming systems by rational structural modifications of both donors and acceptors.

中文翻译：

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由三氮杂tru烯供体和以N-杂芳烃为核心的受体组成的新激基复合物系统

在这项研究中，分别将具有甲基，苯基和对甲苯基侧基的三个基于三氮杂Ph烯的分子Tr-Me，Tr-Ph和Tr-Tol与三个受体3P-T2T，3P-T2P和3P混合-派尔分别具有苯基吡唑外围物质和三嗪，嘧啶和吡啶核的特征，以生成九种共混物的阵列，以探讨形成激基复合物的可行性。与原始供体和受体膜相比，观察到的红移发射是激基复合物形成的良好指示。激基复合物的发射主要受受体的N-杂芳烃核的特征调节，而供体的HOMO受取代基的影响较小。从这些D：A组合的筛选中得出的结论是，由Tr-Ph和Tr-Tol作为供体以及3P-T2T和3P-T2P组成的四种形成复合物的混合物由于受体具有适合OLED应用的有希望的特性。其中，采用Tr-Tol：3P-T2P共混物作为发射层的绿色器件以最佳效率执行，最大外部量子效率（EQE _max）高达12.8％。这些新的激基复合物形成系统作为新开发的荧光发射器（DT）₂ BTh2CN的共宿主被进一步探索。的Tr的-PH：3P-T2P混合物被发现作为最好的主机，得到深红色（EL λ_最大671纳米，CIE（0.68，0.31））的OLED器件与EQE_最大为5.52％。从瞬态光致发光研究中提取的数据阐明了由Förster能量转移主导的发射机理，同时遭受了竞争的Dexter能量转移淬灭。我们的结果突出了使用三氮杂卓烯作为激基复合物形成的给体的可行性，以及通过对给体和受体进行合理的结构修饰，激基复合物形成系统的发射波长的可调性。