Ma Suqian, Liu Yingjie, Zhang Jibo, Xu Bin, Tian Wenjing
State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun 130012, China.
The Key Laboratory of Bionic Engineering, Ministry of Education, Jilin University, Changchun 130025, China.
J Phys Chem Lett. 2020 Dec 17;11(24):10504-10510. doi: 10.1021/acs.jpclett.0c02917. Epub 2020 Dec 7.
The photoluminescence properties of organic fluorescent materials in the solid state are closely related to their aggregation structures. Herein, we present an organic fluorescent molecule 9,10-bis(2,2-di(4-fluorophenyl)vinyl)anthracene (BDFVA) with two crystal polymorphisms to provide an ideal molecular model for understanding the nature of luminescence from the J- and X-aggregates. Detailed structural and photophysical studies reveal that both J- and X-aggregate crystals exhibit enhanced emission in comparison with the corresponding dilute solution because of crystallization-induced emission enhancement (CIEE). Additionally, the X-aggregate (B-phase) crystal with crossed molecular packing exhibits a higher fluorescence efficiency (Φ = 0.60), giving a 1.4-fold promotion of Φ compared to the J-aggregate crystal (G-phase) with staggered molecular packing because the split excited states are all optically allowed in the X-aggregate. Optical waveguide experiments show that the two crystals exhibit excellent amplified spontaneous emission (ASE), demonstrating a promising potential application in organic solid-state lasers.
固态有机荧光材料的光致发光特性与其聚集结构密切相关。在此，我们展示了一种具有两种晶体多晶型的有机荧光分子9,10-双(2,2-二(4-氟苯基)乙烯基)蒽(BDFVA)，以提供一个理想的分子模型来理解J-聚集体和X-聚集体的发光本质。详细的结构和光物理研究表明，由于结晶诱导发光增强(CIEE)，J-聚集体和X-聚集体晶体与相应的稀溶液相比都表现出增强的发射。此外，具有交叉分子堆积的X-聚集体(B相)晶体表现出更高的荧光效率(Φ = 0.60)，与具有交错分子堆积的J-聚集体晶体(G相)相比，Φ提高了1.4倍，因为在X-聚集体中分裂的激发态都是光学允许的。光波导实验表明，这两种晶体都表现出优异的放大自发发射(ASE)，在有机固态激光器中显示出有前景的潜在应用。
