Aggregation-Induced Delayed Fluorescence through Seed-Induced Crystallization
Aggregation-Induced Delayed Fluorescence through Seed-Induced Crystallization
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DOI：
10.1021/acs.jpcc.2c03921
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发表时间：
2022-10
期刊：
影响因子：
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通讯作者：
Kwang-Won Park;Trisha L. Andrew
中科院分区：
文献类型：
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作者：
Kwang-Won Park;Trisha L. Andrew
分子半导体薄膜中的三重态激子对于制备高效有机发光二极管是不可或缺的。表现出热激活延迟荧光（TADF）的分子允许可靠地接近三重态激子，而不需要昂贵的重金属部分。然而，大多数TADF发射体需要在主体基质中稀释以防止自猝灭，这使器件制造复杂化，并且还对器件叠层内的电荷平衡提出了严格的要求，该电荷平衡容易随着老化而被破坏。在这里，我们详细介绍了一种分子的光物理，它在不需要稀释的情况下，在纯净的薄膜中显示出增强的量子产率和延迟荧光。芳族酮，Dp-IFD，可以组织成结晶，纳米结构的薄膜与一个coconene种子层。这些结晶膜表现出增强的光吸收，放大的发射量子产率，和较长的激发态寿命相比，稀溶液。我们使用稳态和时间分辨光谱，以确认Dp-IFD的结晶纳米结构薄膜显示聚集诱导的延迟荧光。
: Triplet excitons in molecular semiconductor films are integral for producing high-efficiency organic light-emitting diodes. Molecules exhibiting thermally activated delayed fluorescence (TADF) allow for reliable access to triplet excitons without the need for expensive heavy-metal moieties. However, most TADF emitters need to be diluted in a host matrix to prevent self-quenching, which complicates device fabrication and, also, places stringent requirements on charge balance within the device stack that can be easily disrupted with aging. Here, we detail the photophysics of a molecule that displays enhanced quantum yields and delayed fluorescence in neat thin films, without the need for dilution. The aromatic ketone, Dp-IFD, can be organized into crystalline, nanostructured films with an ultrathin coronene seed layer. These crystalline films exhibit enhanced light absorption, amplified emission quantum yields, and longer excited state lifetimes compared to dilute solutions. We use stead-state and time-resolved spectroscopy to confirm that crystalline nanostructured films of Dp-IFD display aggregation-induced delayed fluorescence.