Fabricating polythiophene into highly aligned microwire film by fast evaporation of its whisker solution

A facile template-free approach to fabricate poly(3-hexylthiophene) (P3HT) into highly aligned microwire film on a large scale via the evaporation of P3HT/Anisole whisker solution has been developed. The microwires in the film typically have the height of 0.8–1.4 μm, width of 2–4 μm and length of 50–1000 μm. X-ray Diffraction and Selected-Area Electron Diffraction results suggest that each microwire is a single crystal with the reduced packing distance of P3HT chains along the π–π stacking direction (d[010] of 6.5 Å) and the interchain direction (d[100] of 15.7 Å). The closer packing of P3HT chains is likely the key factor promoting the formation of the highly aligned microwires. The aligned P3HT microwire films perform enhanced electrical conductivity, and show no substrate dependence, thus can be fabricated into organic electronic devices in situ.