Ko Jongkuk, Kim Youngkeol, Kang Jin Soo, Berger Rüdiger, Yoon Hyunsik, Char Kookheon
The National Creative Research Initiative Center for Intelligent Hybrids, The WCU Program of Chemical Convergence for Energy and Environment, School of Chemical and Biological Engineering, Seoul National University, Seoul, 08826, Korea.
Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
Adv Mater. 2020 Mar;32(10):e1908087. doi: 10.1002/adma.201908087. Epub 2020 Jan 27.
The morphology of conjugated polymers has critical influences on electronic and optical properties of optoelectronic devices. Even though lots of techniques and methods are suggested to control the morphology of polymers, very few studies have been performed inducing high charge transport along out-of-plane direction. In this study, the self-assembly of homo- and blended conjugated polymers which are confined in nanostructures is utilized. The resulting structures lead to high charge mobility along vertical direction for both homo- and blended conjugated polymers. Both semicrystalline and amorphous polymers show highly increased population of face-on crystallite despite intrinsic crystallinity of polymers. They result in more than two orders of magnitude enhanced charge mobility along vertical direction revealed by nanoscale conductive scanning force microscopy and macroscale IV characteristic measurements. Moreover, blends of semicrystalline and amorphous polymers, which are known to show inferior optical and electrical properties due to their structural incompatibility, are formed into harmonious states by this approach. Assembly of blends of semicrystalline and amorphous polymers under nanoconfinement shows charge mobility in out-of-plane direction of 0.73 cm V s with wide range of absorption wavelength from 300 to 750 nm demonstrating the synergistic effects of two different polymers.
共轭聚合物的形态对光电器件的电子和光学性质具有至关重要的影响。尽管人们提出了许多技术和方法来控制聚合物的形态，但很少有研究致力于诱导电荷沿面外方向进行高效传输。在本研究中，我们利用了受限在纳米结构中的均相共轭聚合物和共混共轭聚合物的自组装。所得结构使均相共轭聚合物和共混共轭聚合物在垂直方向上都具有高电荷迁移率。无论是半结晶聚合物还是无定形聚合物，尽管其本身具有结晶度，但都显示出大量的面朝上微晶。通过纳米级导电扫描力显微镜和宏观IV特性测量表明，它们导致垂直方向上的电荷迁移率提高了两个以上数量级。此外，已知由于结构不相容而表现出较差光学和电学性质的半结晶聚合物和无定形聚合物的共混物，通过这种方法形成了和谐的状态。在纳米限域条件下，半结晶聚合物和无定形聚合物共混物的组装在面外方向上显示出0.73 cm V s的电荷迁移率，吸收波长范围从300到750 nm，这证明了两种不同聚合物的协同效应。
