表面接枝聚(3-烷基噻吩)於奈米碳管之合成與光電性質研究

The Synthesis and Optoelectronic Behaviour of Conjugated Polymer Poly(3-hexylthiophene) P3HT Grafted on the surface of Multi-Walled Carbon Nanotubes

黎英芳(Le Anh Phuong)

指導教授 ： 楊長謀

國立清華大學/工學院/材料科學工程學系/碩士(2010年)

https://doi.org/10.6843/NTHU.2010.00312

摘要

A nanocomposite of multi-walled carbon nanotubes (MWCNTs) and poly(3-hexylthiophene) (P3HT) was prepared by grafting P3HT on the surface of CNTs via a “grafting from” method. By using chemical oxidative polymerization with controlling the reaction condition, different coating thickness of P3HT on MWCNTs was obtained. P3HT grafted on the surface of MWCNTs (P3HT-g-CNT) are soluble in common organic solvents. Fourier Transform Infrared (FT-IR) spectra was employed to characterize the change in the surface functionalities. The transmission electron microscopy (TEM) micrographs showed the uniform coating of P3HT on CNTs with the thickness 2.1 nm, 3.6 nm and 8.3 nm. Thermogravimetric analysis (TGA) was used to study the polymer content grafted on the surface of MWCNTs. The wide-angle X-ray scattering (WAXS) presented the disordered structure of P3HT chains grafted on CNTs. The Raman scattering indicated that the polymer conformation is modified by π-π interaction with CNTs which causes a shift of P3HT peak from 1445 cm-1 to 1430 cm-1. Furthermore, although the photoluminescence peak of P3HT remained unchanged when grafted on CNTs, modifications of the energy gap of P3HT was observed, indicating variations of vibronic levels arising from the grafting. Moreover, broadening of the PL emission peaks took place that suggested decreasing of lifetimes of the photo-excited species when grafted on CNTs. The bilayer photovoltaic devices based on pure P3HT blended with P3HT-g-CNT (P3HT/P3HT-g-CNT) as the electron donor and [6,6]-phenyl C61-butyric acid methyl ester (PCBM) as the electron-acceptor showed an enhanced photocurrent density and power conversion efficiency compared to photovoltaic devices based on pure P3HT and P3HT/P3HT-g-CNT.

關鍵字

poly(3-hexylthiophene) ； multi-walled carbon nanotubes ； a "grafting from" method ； photovoltaic behaviour

參考文獻

1. S. Iijima, Nature 1991, 354, 56-58.

5. A. J. Miller, R. A. Hatton, S. R. P. Silva, Apply. Phys. Lett. 2006, 89, 133117.

6. C. W. Lin, L. C. Huang, A. C-M. Yang, Macromolecules 2008, 41, 4978.

8. Y. Kanai, J. C. Grossman, Nano lett. 2008, 8, 3.

12. E. Kymakis et al., Nanotechnology 2007, 18, 435702.