通過可調籠型支架實現熱應力超分子納米複合材料中的弗倫克爾激子
作者:
小柯機器人發布時間:2020/11/19 10:47:23
美國紐約城市大學的城市學院Dorthe M. Eisele研究小組的通過可調籠型支架實現熱應力超分子納米複合材料中的弗倫克爾激子。 該研究於2020年發表於國際一流學術期刊《自然—化學》。
非定域弗倫克爾(Frenkel)激子——在發色團之間的相干共享激子——是光合生物體內超分子集光裝置效率顯著的原因。由於所用超分子結構的脆弱性和Frenkel激子的脆弱性,尤其是在溫和變化的溶劑條件和高溫下以及沉積在固體基底上時,自然設計原理在光電器件中的應用受到了限制。
在該研究中,研究人員通過合成穩定的超分子捕光納米管來克服這些功能化障礙,這些納米管由可調諧(~4.3–4.9nm)、均勻(±0.3nm)籠狀支架實現。高分辨低溫電子顯微鏡結合掃描電子顯微鏡、寬頻飛秒瞬態吸收光譜和近場掃描光學顯微鏡,發現籠狀支架內的激子即使在極端熱應力下也具有很強的穩定性,而對納米複合材料尺寸的控制是在固體基底上進行的。
研究人員開發的仿生納米複合材料為開發由穩定超分子材料製成的下一代有機器件提供了一個總體框架。
大自然成功地將超分子組件用於高效和強大的太陽能收集;然而,由於所用超分子結構的脆弱性和Frenkel激子的脆弱性等穩定性問題,限制了模擬此類材料系統在光電器件中應用。現在,在可調籠狀支架的支持下,穩定的超分子光收集納米管已經被合成,即使在熱應力下也很穩定。
附:英文原文
Title: Frenkel excitons in heat-stressed supramolecular nanocomposites enabled by tunable cage-like scaffolding
Author: Kara Ng, Megan Webster, William P. Carbery, Nikunjkumar Visaveliya, Pooja Gaikwad, Seogjoo J. Jang, Ilona Kretzschmar, Dorthe M. Eisele
Issue&Volume: 2020-11-16
Abstract: 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 (~4.3–4.9nm), uniform (±0.3nm) 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.
DOI: 10.1038/s41557-020-00563-4
Source: https://www.nature.com/articles/s41557-020-00563-4