Surface Structure of Semicrystalline Naphthalene Diimide–Bithiophene Copolymer Films Studied with Atomic Force Microscopy
Surface Structure of Semicrystalline Naphthalene Diimide–Bithiophene Copolymer Films Studied with Atomic Force Microscopy
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DOI：
10.1021/acs.macromol.6b00988
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发表时间：
2016-08
期刊：
影响因子：
5.5
通讯作者：
Mario Zerson;M. Neumann;Robert Steyrleuthner;D. Neher;R. Magerle
中科院分区：
文献类型：
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作者：
Mario Zerson;M. Neumann;Robert Steyrleuthner;D. Neher;R. Magerle
半导体聚合物的结晶行为、表面结构和纳米力学性质在理解电荷注入过程、电荷载流子的传输和材料的加工性方面起着至关重要的作用。在这里，我们研究半导体共聚物聚（[N，N′-双（2-辛基十二烷基）-11-萘-1，4，5，8-双（二甲酰亚胺）-2，6-二基]-alt-5，5 ′-（2，2 ′-12-bithiophene））（P（NDI 2 OD-T2）），并通过间歇接触式原子力显微镜（AFM）和基于AFM的幅度-相位-距离（APD）曲线测量研究了退火条件对其表面结构的影响。对于旋铸薄膜以及在高达320 °C的温度下退火的薄膜，我们发现结晶薄片的边缘暴露在表面。如尖端压痕所示，1.2 nm厚的烷基侧链层覆盖膜表面。这表明，电荷注入到P（NDI_2 OD-T_2）薄膜中并不受非晶材料表面层的阻碍。
The crystallization behavior, the surface structure, and the nanomechanical properties of a semiconducting polymer play a crucial role in understanding the charge injection process, the transport of the charge carriers and the processability of the material. Here we study the semiconducting copolymer poly([N,N′-bis(2-octyldodecyl)-11-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5′-(2,2′-12 bithiophene)) (P(NDI2OD-T2)) and investigate the influence of annealing conditions on its surface structure through intermittent contact mode atomic force microscopy (AFM) and AFM-based measurements of amplitude–phase–distance (APD) curves. For spin-cast thin films as well as for films annealed at temperatures up to 320 °C, we find that the edges of crystalline lamellae are exposed at the surface. A 1.2 nm thick layer of alkyl side chains covers the film surface as indicated by the tip indentation. This suggests that charge injection into P(NDI2OD-T2) films is not hindered by a surface layer of amorphous mater...