Anisotropic Properties of Aligned π-Conjugated Polymer Films Fabricated by Capillary Action and Their Post-Annealing Effects

Uniaxially aligned films of thiophene-based polymers were successfully fabricated by a novel film-forming method using the capillary action of polymer solutions without applying any mechanical or thermal stress to the polymers. Unique optical and electrical anisotropies were studied in the poly(2,5-bis(3-alkylthiophene-2-yl)thieno[3,2- b ]thiophene) (pBTTT) and poly(2,5-bis(3-alkylthiophene-2-yl)thieno[2,3- b ]thiophene) (pBTCT) films fabricated by the method. Moreover, the improvements of the optical and electrical properties of the aligned polymer films by thermal annealing were also demonstrated.