Large Femtosecond Two-Photon Absorption Cross Sections of Fullerosome Vesicle Nanostructures Derived from a Highly Photoresponsive Amphiphilic C60-Light-Harvesting Fluorene Dyad

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• 作者：Min Wang ; Venkatram Nalla ; Seaho Jeon ; Venkatesh Mamidala ; Wei Ji ; Loon-Seng Tan ; Thomas Cooper ; Long Y. Chiang
• 刊名：Journal of Physical Chemistry C
• 出版年：2011
• 出版时间：September 29, 2011
• 年：2011
• 卷：115
• 期：38
• 页码：18552-18559
• 全文大小：993K
• 年卷期：v.115,no.38(September 29, 2011)
• ISSN：1932-7455

文摘

We demonstrated ultrafast femtosecond nonlinear optical (NLO) absorption characteristics of bilayered fullerosome vesicle nanostructures derived from molecular self-assembly of amphiphilic oligo(ethylene glycolated) C₆₀-(light-harvesting diphenylaminofluorene antenna). Fullerene conjugates were designed to enhance photoresponse in a femtosecond time scale by applying an isomerizable periconjugation linker between the C₆₀ cage and a diphenylaminofluorene antenna subunit in an intramolecular contact distance of only <3.0 脜. Morphology of C₆₀(>DPAF-EG₁₂C₁)-based fullerosome nanovesicles in H₂O was characterized to consist of a bilayered shell with a sphere diameter of 20鈥?0 nm and a chromophore shell width of 9.0鈥?0 nm, fitting well with a head-to-head packing configuration of the molecular length. At the estimated effective nanovesicle concentration as low as 5.5 脳 10^鈥? MV (molecular molar concentration of 5.0 脳 10^鈥? M) in H₂O, two-photon absorption (2PA) phenomena were found to be the dominating photophysical events showing a large molar concentration-insensitive 2PA cross-section value equivalent to 8500 GM in a form of nanovesicles, on average. The observed NLO characteristics led to a sharp trend of efficient light-transmittance intensity reduction at the input laser intensity above 100 GW/cm².