Triplet-triplet-annihilation (TTA) upconversion sensitized by a new thermally activated delayed fluorescence (TADF) molecule, BTZ-DMAC-4Br, is investigated in whispering gallery mode (WGM) microcavities made of toluene solutions filled into quartz capillaries. Since the utilization of the excitation light is improved in WGM microcavities through total internal reflection, the upconversion efficiency is enhanced greatly and an upconversion quantum yield of 24.6% is observed, which is a dozen times higher than that measured in conventional cuvettes. To the best of knowledge, this is the highest upconversion efficiency achieved in TADF sensitized TTA systems. Not only is a new material designed, but also the results provide a novel way to improve the TTA upconversion performance by utilizing the optical cavity effect, and the TTA microcavities may be used to construct highly efficient and low-threshold photonic devices in many applications.

中文翻译：

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由光学微腔中热活化延迟荧光分子敏化的高效三重-三重湮灭上转换

在由填充到石英毛细管中的甲苯溶液制成的回音壁模式 (WGM) 微腔中研究了由新的热激活延迟荧光 (TADF) 分子 BTZ-DMAC-4Br 敏化的三重三重湮灭 (TTA) 上转换。由于全内反射提高了 WGM 微腔中激发光的利用率，因此上转换效率大大提高，上转换量子产率为 24.6%，是传统比色皿测量的十倍以上。据了解，这是在 TADF 敏化 TTA 系统中实现的最高上转换效率。不仅设计了一种新材料，而且结果还提供了一种利用光腔效应提高 TTA 上转换性能的新方法，