Recently, diboron based blue thermally activated delayed fluorescence (TADF) material, N7,N7,N13,N13,5,9,11,15-octaphenyl-5,9,11,15-tetrahydro-5,9,11,15-tetraaza-19b, 20b-diboradinaphtho[3,2,1-de:1′,2′,3′-jk] pentacene-7,13-diamine (ν-DABNA) has drawn attention from the researchers due to its good device performances as well as narrow full-width at half maximum (FWHM) in OLED devices. In this work, we report a detailed analysis to understand the exact reason behind the efficiency variations in ν-DABNA based TADF devices using different types of host materials. Interestingly, we found that triplet exciton density of ν-DABNA molecule is mainly located at the central region, so the triplet exciton energy transfer from the host material is hindered due to the presence of peripheral diphenylamine extensions. Hence, our analysis suggests that utilizing wide band gap host materials in ν-DABNA based TADF devices exhibit excellent device efficiencies with the support of trap assisted emission mechanism. This study brings an in-depth understanding of efficiency variations in the ν-DABNA based OLED devices.

最近，基于二硼的蓝色热激活延迟荧光（TADF）材料，N7,N7,N13,N13,5,9,11,15-octaphenyl-5,9,11,15-tetrahydro-5,9,11,15- tetraaza-19b, 20b-diboradinaphtho[3,2,1-de:1′,2′,3′-jk] 并五苯-7,13-二胺（ν-DABNA）因其良好的装置而受到研究人员的关注OLED 器件的性能以及窄的半峰全宽 (FWHM)。在这项工作中，我们报告了详细的分析，以了解使用不同类型的主体材料的基于 ν-DABNA 的 TADF 器件效率变化背后的确切原因。有趣的是，我们发现 ν-DABNA 分子的三重态激子密度主要位于中心区域，因此由于外围二苯胺延伸的存在，阻碍了从主体材料的三重态激子能量转移。因此，我们的分析表明，在基于 ν-DABNA 的 TADF 器件中使用宽带隙主体材料在陷阱辅助发射机制的支持下表现出出色的器件效率。本研究深入了解基于 ν-DABNA 的 OLED 器件的效率变化。