Zhang Yifan, Shaikh Huda, Sneyd Alexander J, Tian Jia, Xiao James, Blackburn Arthur, Rao Akshay, Friend Richard H, Manners Ian
Department of Chemistry, University of Victoria, Victoria, British Columbia V8W 3 V6, Canada.
Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge CB3 OHE, United Kingdom.
J Am Chem Soc. 2021 May 12;143(18):7032-7041. doi: 10.1021/jacs.1c01571. Epub 2021 Apr 27.
Hybrid systems composed of conjugated polymers and inorganic semiconductor nanocrystals such as quantum dots (QDs) and nanorods (QRs) represent highly desirable multifunctional materials for applications from energy harvesting to light emission and sensing. Herein, we describe energy transfer studies between low-dispersity segmented conjugated polymer micellar nanofibers integrated with quantum dots that are spatially confined to discrete regions in the hybrid assembly via noncovalent interactions. The nanofibers were prepared from diblock copolymers with a crystallizable poly(di--hexylfluorene) (PDHF) core-forming block and different corona-forming blocks using the seeded-growth "living" crystallization-driven self-assembly method. The highly ordered crystalline PDHF core in the fibers functions as a donor and permits long-range exciton transport (>200 nm). Energy can therefore be funneled through the fiber core to QDs and QRs that function as acceptor materials and which are noncovalently bound to spatially defined coronal regions of poly(2-vinylpyridine) (P2VP) or quaternized polyfluorene (QPF). Using steady-state and time-resolved spectroscopy, we demonstrate that efficient energy transfer (over 70%) occurs from the crystalline PDHF donor core to the acceptor CdSe QRs attached at the fiber termini. The emission of the PDHF donor in the hybrid conjugate was extensively quenched (by 84%), and a subsequent 4-fold enhancement of the QR emission in solution was observed. These results indicate that the conjugates prepared in this work show promise for potential applications in fields such as light-emitting diodes, photovoltaics, chemical sensors, and photocatalysis.
由共轭聚合物与无机半导体纳米晶体（如量子点（QD）和纳米棒（QR））组成的混合系统是一类非常理想的多功能材料，可应用于从能量收集到发光及传感等多个领域。在此，我们描述了低分散性的分段共轭聚合物胶束纳米纤维与量子点之间的能量转移研究，这些量子点通过非共价相互作用在混合组装体中被空间限制在离散区域。纳米纤维由具有可结晶的聚（二 - 己基芴）（PDHF）成核嵌段和不同的冠状嵌段的二嵌段共聚物，采用种子生长“活性”结晶驱动自组装方法制备。纤维中高度有序的结晶PDHF核作为供体，允许长程激子传输（>200 nm）。因此，能量可以通过纤维核汇集到作为受体材料的量子点和纳米棒上，它们通过非共价键结合到聚（2 - 乙烯基吡啶）（P2VP）或季铵化聚芴（QPF）的空间定义冠状区域。使用稳态和时间分辨光谱，我们证明了从结晶PDHF供体核到附着在纤维末端的受体CdSe纳米棒发生了高效的能量转移（超过70%）。混合共轭物中PDHF供体的发射被大量淬灭（84%），随后观察到溶液中纳米棒发射增强了4倍。这些结果表明，本文制备的共轭物在发光二极管、光伏、化学传感器和光催化等领域具有潜在应用前景。
