Dye doped organic thin films with controllable molecular aggregation and emission properties are of broad interest to the scientific community owing to their large number of potential applications in physics, chemistry, and materials science. Here, a spray coating method was used to prepare perylenebisimides (PBI) doped polymer films. In this study, the effects of the dye concentration, polymer matrix, solvent, and casting process on the optical properties of the resulting films were studied. The aggregation of the PBI into monomer, dimer, and oligomer forms, was rapidly and simply controlled based on the concentration dependence of PBI. The molecular aggregation mechanism in the film forming process for PBI doped polystyrene (PS) was further analyzed by computer simulations. The blends rapidly reached their lowest Gibbs free energy owing to the “frozen” polymer chains and confinement of PBI, molecules with different aggregation states. Therefore, the PBIs/PS films prepared under different conditions had different fluorescent lifetimes and absolute quantum yields. Narrow emission, amplified spontaneous emission (ASE) and random lasing (RL) were observed in PBI doped PS films when photo-pumped at 532 nm in transmittance and waveguide modes, respectively. A lower ASE and RL threshold were obtained for PS films doped with monomeric PBI than those in other aggregation states. Moreover, the solvent use in film deposition greatly influenced the emission properties of the PS films by altering their microstructures. These results indicate potential applications for spray coated dye/polymer films in organic solid-state lasers.

中文翻译：

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具有可控分子聚集状态和发射特性的喷涂苝双酰亚胺/聚合物薄膜

具有可控分子聚集和发射特性的染料掺杂有机薄膜因其在物理、化学和材料科学中的大量潜在应用而受到科学界的广泛关注。在这里，喷涂方法用于制备苝双酰亚胺（PBI）掺杂的聚合物薄膜。在这项研究中，研究了染料浓度、聚合物基质、溶剂和流延工艺对所得薄膜光学性能的影响。PBI 聚合成单体、二聚体和低聚物形式，可以根据 PBI 的浓度依赖性快速简单地控制。通过计算机模拟进一步分析了PBI掺杂聚苯乙烯（PS）成膜过程中的分子聚集机制。由于“冻结”的聚合物链和 PBI（具有不同聚集状态的分子）的限制，共混物迅速达到其最低吉布斯自由能。因此，在不同条件下制备的 PBIs/PS 薄膜具有不同的荧光寿命和绝对量子产率。当在透射率和波导模式下分别在 532 nm 处进行光泵浦时，在 PBI 掺杂的 PS 薄膜中观察到窄发射、放大自发发射 (ASE) 和随机激光 (RL)。与其他聚合状态相比，掺杂单体 PBI 的 PS 薄膜的 ASE 和 RL 阈值较低。此外，薄膜沉积中使用的溶剂通过改变其微观结构极大地影响了 PS 薄膜的发射特性。这些结果表明了喷涂染料/聚合物薄膜在有机固态激光器中的潜在应用。