Nagamatsu Shuichi, Pandey Shyam S
Department of Physics and Information Technology, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka, Fukuoka, 820-8502, Japan.
Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, 2-4 Hibikino, Wakamatsu-ku, Kitakyushu, 808-0196, Japan.
Sci Rep. 2020 Nov 18;10(1):20020. doi: 10.1038/s41598-020-77022-0.
An ordered arrangement of electron-accepting molecular dopant, 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ), in three-dimensionally (3D) oriented poly(3-hexylthiophene) (P3HT) film was clarified. The 3D oriented P3HT thin films prepared by the friction-transfer technique were doped with F4TCNQ by dipping into an acetonitrile solution. The presence of F4TCNQ anions in the 3D oriented P3HT thin films was investigated by polarized ultraviolet/visible/near-infrared absorption spectroscopy, grazing incidence X-ray diffractometry, polarized Fourier transform infrared spectroscopy (FT-IR), and infrared p-polarized multiple-angle incidence resolution spectroscopy (pMAIRS). The F4TCNQ-doped 3D oriented P3HT films showed anisotropic properties in all characterizations. In particular, the anisotropic molecular vibrations from polarized FT-IR and pMAIRS have clearly revealed orientations of polymeric chains and molecular dopant molecules. Considering the results from several independent techniques indicated that F4TCNQ anions in the 3D oriented P3HT were orderly arranged in a 3D manner with respect to the 3D oriented P3HT such that their molecular long-axis parallel to the P3HT backbone, with in-plane molecular orientation. Additionally, the direction of the optical transition moment of the F4TCNQ anion was found to be parallel to the molecular short-axis.
阐明了电子接受性分子掺杂剂2,3,5,6-四氟-7,7,8,8-四氰基对苯二醌二甲烷（F4TCNQ）在三维（3D）取向的聚（3-己基噻吩）（P3HT）薄膜中的有序排列。通过摩擦转移技术制备的3D取向P3HT薄膜通过浸入乙腈溶液中用F4TCNQ进行掺杂。通过偏振紫外/可见/近红外吸收光谱、掠入射X射线衍射、偏振傅里叶变换红外光谱（FT-IR）和红外p偏振多角度入射分辨率光谱（pMAIRS）研究了3D取向P3HT薄膜中F4TCNQ阴离子的存在情况。F4TCNQ掺杂的3D取向P3HT薄膜在所有表征中均表现出各向异性。特别是，来自偏振FT-IR和pMAIRS的各向异性分子振动清楚地揭示了聚合物链和分子掺杂剂分子的取向。综合几种独立技术的结果表明，3D取向P3HT中的F4TCNQ阴离子相对于3D取向P3HT以三维方式有序排列，使得它们的分子长轴与P3HT主链平行，具有面内分子取向。此外，发现F4TCNQ阴离子的光学跃迁矩方向与分子短轴平行。
