Frenkel excitons in heat-stressed supramolecular nanocomposites enabled by tunable cage-like scaffolding
Frenkel excitons in heat-stressed supramolecular nanocomposites enabled by tunable cage-like scaffolding
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DOI：
10.1038/s41557-020-00563-4
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发表时间：
2020-11-16
期刊：
影响因子：
21.8
通讯作者：
Eisele, Dorthe M.
中科院分区：
文献类型：
--
作者：
Ng, Kara;Webster, Megan;Eisele, Dorthe M.
离域弗伦克尔激子——在发色团之间相干共享激发——是光合生物中超分子光收集组件的显著效率的原因。由于所使用的超分子结构的脆弱性和Frenkel激子的微妙性质，特别是在温和变化的溶剂条件和高温下以及沉积在固体衬底上，将自然设计原则转化为光电子器件的应用受到了限制。在这里，我们通过组成稳定的超分子光收集纳米管来克服这些功能化障碍，该纳米管由可调谐（类似4.3-4.9 nm），均匀（+/- 0.3 nm）笼状支架实现。高分辨率低温电子显微镜，结合扫描电子显微镜，宽带飞秒瞬态吸收光谱和近场扫描光学显微镜显示，即使在极端热应力下，笼状支架内的激子也是坚固的，并且在固体衬底上保持对纳米复合材料尺寸的控制。我们的仿生纳米复合材料为开发由稳定的超分子材料制成的下一代有机器件提供了一个总体框架。
Delocalized Frenkel excitons-coherently shared excitations among chromophores-are responsible for the remarkable efficiency of supramolecular light-harvesting assemblies within photosynthetic organisms. The translation of nature's design principles to applications in optoelectronic devices has been limited by the fragility of the supramolecular structures used and the delicate nature of Frenkel excitons, particularly under mildly changing solvent conditions and elevated temperatures and upon deposition onto solid substrates. Here, we overcome those functionalization barriers through composition of stable supramolecular light-harvesting nanotubes enabled by tunable (similar to 4.3-4.9 nm), uniform (+/- 0.3 nm) cage-like scaffolds. High-resolution cryogenic electron microscopy, combined with scanning electron microscopy, broadband femtosecond transient absorption spectroscopy and near-field scanning optical microscopy revealed that excitons within the cage-like scaffolds are robust, even under extreme heat stress, and control over nanocomposite dimensions is maintained on solid substrates. Our bio-inspired nanocomposites provide a general framework for the development of next-generation organic devices made from stable supramolecular materials.