Oh Saejin, Yang Myungjae, Kang Seulki, Chung Sung-Hee, Bouffard Jean, Hong Seunghun, Park So-Jung
Department of Chemistry and Nanoscience , Ewha Womans University , 52 Ewhayeodae-gil, Seodaemun-gu , Seoul 03760 , Korea.
Department of Physics and Astronomy and Institute of Applied Physics , Seoul National University , Seoul 151-747 , Korea.
ACS Appl Mater Interfaces. 2019 Aug 7;11(31):28538-28545. doi: 10.1021/acsami.9b08892. Epub 2019 Jul 25.
Controlling the nanoscale morphology of conducting polymer/nanoparticle hybrid films is a highly desired but challenging task. Here, we report that such functional hybrid films with unprecedented structural order can be formed through the self-assembly of conjugated block copolymers and CdSe quantum dots at the air-water interface. The one-step assembly of quantum dots and block copolymers composed of polythiophene and polyethylene glycol (P3HT--PEG) at the fluidic interface generated a highly ordered assembly structure of P3HT nanowires and one-dimensional quantum dot arrays. Structure analyses revealed a unique self-assembly behavior and size dependency, which are distinct from the conventional self-assembly of coil-type polymers on solid substrates. Interestingly, hydrophobic quantum dots reside at the interface between P3HT and PEG domains without disrupting the P3HT packing structure, which is advantageous for the optoelectronic properties. Furthermore, large particles bridge the P3HT nanowires at both ends, while small particles decorate each P3HT/PEG interfaces, thus forming tight p-n junctions for a broad size range of nanoparticles. The nanoparticle-incorporated hybrid films showed more than an order of magnitude higher photocurrent and light sensitivity compared to polymer-only films, consistent with the assembly structure with close contact between the organic and inorganic semiconductors.
控制导电聚合物/纳米粒子混合薄膜的纳米级形态是一项备受期待但具有挑战性的任务。在此，我们报告称，通过共轭嵌段共聚物和CdSe量子点在空气-水界面的自组装，可以形成具有前所未有的结构有序性的此类功能混合薄膜。量子点与由聚噻吩和聚乙二醇（P3HT-PEG）组成的嵌段共聚物在流体界面的一步组装产生了P3HT纳米线和一维量子点阵列的高度有序组装结构。结构分析揭示了一种独特的自组装行为和尺寸依赖性，这与传统的线圈型聚合物在固体基质上的自组装不同。有趣的是，疏水性量子点位于P3HT和PEG域之间的界面处，而不会破坏P3HT堆积结构，这对光电性能有利。此外，大颗粒在两端桥接P3HT纳米线，而小颗粒装饰每个P3HT/PEG界面，从而为广泛尺寸范围的纳米颗粒形成紧密的p-n结。与仅聚合物薄膜相比，掺入纳米颗粒的混合薄膜显示出高一个数量级以上的光电流和光灵敏度，这与有机和无机半导体之间紧密接触的组装结构一致。
