Thanippuli Arachchi Dimuthu H, Barotov Ulugbek, Perkinson Collin F, Šverko Tara, Kaplan Alexander E K, Bawendi Moungi G
Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States.
ACS Nano. 2024 Jul 24. doi: 10.1021/acsnano.4c04732.
We introduce a two-step silica-encapsulation procedure to optimize both the optical efficiency and structural robustness of 5,5',6,6'-tetrachloro-1,1'-diethyl-3,3'-di(4-sulfobutyl)-benzimidazolocarbocyanine (TDBC), a two-dimensional sheet-like J-aggregate. We report a fluorescence quantum yield of ∼98%, the highest quantum yield recorded for any J-aggregate structure at room temperature, and a fast, emissive lifetime of 234 ps. Silica, as an encapsulating matrix, provides optical transparency, chemical inertness, and robustness to dilution, while rigidifying the J-aggregate structure. Our in situ encapsulation process preserves the excitonic structure in TDBC J-aggregates, maintaining their light absorption and emission properties. The homogeneous silica coating has an average thickness of 0.5-1 nm around J-aggregate sheets. Silica encapsulation permits extensive dilutions of J-aggregates without significant disintegration into monomers. The narrow absorbance and emission line widths exhibit further narrowing upon cooling to 79 K, which is consistent with J-type coupling in the encapsulated aggregates. This silica TDBC J-aggregate construct signifies (1) a bright, fast, and robust fluorophore system, (2) a platform for further manipulation of J-aggregates as building blocks for integration with other optical materials and structures, and (3) a system for fundamental studies of exciton delocalization, transport, and emission dynamics within a rigid matrix.
我们介绍了一种两步法二氧化硅封装程序，以优化5,5',6,6'-四氯-1,1'-二乙基-3,3'-二(4-磺丁基)-苯并咪唑碳菁(TDBC，一种二维片状J-聚集体)的光学效率和结构稳健性。我们报告了约98%的荧光量子产率，这是在室温下任何J-聚集体结构所记录的最高量子产率，以及234 ps的快速发射寿命。二氧化硅作为封装基质，提供光学透明度、化学惰性和抗稀释性，同时使J-聚集体结构刚性化。我们的原位封装过程保留了TDBC J-聚集体中的激子结构，维持了它们的光吸收和发射特性。均匀的二氧化硅涂层在J-聚集体片周围的平均厚度为0.5-1 nm。二氧化硅封装允许J-聚集体进行大量稀释而不会显著分解成单体。在冷却至79 K时，窄的吸收和发射线宽进一步变窄，这与封装聚集体中的J型耦合一致。这种二氧化硅TDBC J-聚集体结构意味着：(1) 一个明亮、快速且稳健的荧光团系统；(2) 一个进一步操纵J-聚集体作为与其他光学材料和结构集成的构建块的平台；(3) 一个用于在刚性基质内对激子离域、传输和发射动力学进行基础研究的系统。
