Fernandes José Diego, Pazin Wallance Moreira, Macedo Wagner Costa, Ruiz Gilia Cristine Marques, Constantino Carlos José Leopoldo
School of Technology and Applied Sciences, São Paulo State University (UNESP), Presidente Prudente, 19060-900, São Paulo, Brazil.
Langmuir. 2021 Apr 6;37(13):3836-3848. doi: 10.1021/acs.langmuir.0c03299. Epub 2021 Mar 26.
Since the optical and electrical properties of organic thin films devices depend on their supramolecular arrangement and the molecular chemical structure, the understanding of such characteristics is essential for the optimization of these devices. In this study, we determine the supramolecular arrangement of thin films produced using the Langmuir-Schaefer (LS) technique and explain how its supramolecular arrangement is affected by the molecular chemical structure using two perylene derivatives: bis-butylimide (BuPTCD) and bis-phenethylimide (PhPTCD). The optical absorption measurements reveal that both films grow homogeneously and indicate that the presence of H aggregates (forbidden emission) is higher for BuPTCD LS film than for PhPTCD LS film. Atomic force microscopic analysis shows that the PhPTCD LS film is rougher than the BuPTCD film. In addition, FTIR analyses indicate that both films have head-on molecular organization. XRD patterns reveal that both the BuPTCD LS film and the PhPTCD LS film are crystalline, but that crystallinity is more prevalent in the BuPTCD LS film. Thus, the results show that the difference presented in the chemical structures leads the films to have different supramolecular arrangements, with consequences for their optical properties.
由于有机薄膜器件的光学和电学性质取决于其超分子排列和分子化学结构，因此了解这些特性对于优化这些器件至关重要。在本研究中，我们确定了使用朗缪尔-谢弗（LS）技术制备的薄膜的超分子排列，并使用两种苝衍生物：双丁基酰亚胺（BuPTCD）和双苯乙基酰亚胺（PhPTCD）解释了其超分子排列如何受到分子化学结构的影响。光吸收测量表明，两种薄膜均均匀生长，并且表明BuPTCD LS薄膜中H聚集体（禁戒发射）的存在比PhPTCD LS薄膜中的更高。原子力显微镜分析表明，PhPTCD LS薄膜比BuPTCD薄膜更粗糙。此外，傅里叶变换红外光谱分析表明，两种薄膜均具有头对头的分子排列。X射线衍射图谱表明，BuPTCD LS薄膜和PhPTCD LS薄膜均为晶体，但结晶度在BuPTCD LS薄膜中更为普遍。因此，结果表明化学结构上的差异导致薄膜具有不同的超分子排列，从而影响其光学性质。
