The Aggregation of Poly(3-Hexylthiophene) Into Nanowires: With and Without Chemical Doping
Chemistry and Biochemistry
Non-doped and chemically p-doped poly(3-hexylthiophene) (P3HT) nanowires are investigated by optical spectroscopy and atomic force microscopy (AFM) to reveal the effects of doping on their aggregation processes and nanoscale morphologies. The AFM studies on the non-doped P3HT nanowires formed in the early aggregation stage demonstrate that P3HT molecules will probably go through either packing of high-aspect ratio multi-chain/single-chain aggregates or packing of solubilized individual chains depending on experimental conditions. High-resolution AFM images also show the connecting segments between ordered domains of P3HT. For p-doping of P3HT in the solution phase, the addition of 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (F4-TCNQ), a p-dopant, will greatly accelerate the aggregation rate of 1D P3HT nanostructures. The doped P3HT nanowires are comprised of linearly connected domains that are 40–60 nm wide and 5–10 nm high. Compared with the non-doped P3HT nanowires, doped nanowires show smoother edges and less protruding segments, likely due to a different aggregation mechanism. Furthermore, the doped nanowires tend to agglomerate into disordered bundles and clusters because of the presence of F4-TCNQ counterions and complexity resulting from Coulomb interactions and other doping-induced growth defects.
Journal of Physical Chemistry C
McFarland, F. M.,
Ellis, C. M.,
(2017). The Aggregation of Poly(3-Hexylthiophene) Into Nanowires: With and Without Chemical Doping. Journal of Physical Chemistry C, 121(8), 4740-4746.
Available at: https://aquila.usm.edu/fac_pubs/15243