Wrinkling patterns at the metallized surface of thin polymer films are shown to be sensitive to the sticky or slippery character of the polymer-substrate interface. Existing theoretical models were expanded to specific boundary conditions (adhesive versus slippery) in order to rationalize these observations. Based on this concept, we were able to propose a new and simple method to orient the wrinkles by chemically patterning the substrate with regions of high and low adhesion.
Newly synthesized thiophene (T) and benzothiadiazole (B) co‐oligomers of different size, alternation motifs, and alkyl substitution types are reported. Combined spectroscopic data, electrochemical analysis, and theoretical calculations show that the insertion of a single electron‐deficient B unit into the aromatic backbone strongly affects the LUMO energy level. The insertion of additional B units has only a minor effect on the electronic properties. Cast films of oligomers with two alternated B rings (B–T–B inner core) display crystalline order. Bottom‐contact FETs based on films cast on bare SiO2 show hole‐charge mobilities of 1 × 10−3–5 × 10−3 cm2 V−1s−1 and Ion/Ioff ratios of 105–106. Solution‐cast films of cyclohexyl‐substituted compounds are amorphous and do not show FET behavior. However, the lack of order observed in these films can be overcome by nanorubbing and unconventional wet lithography, which allow for fine control of structural order in thin deposits.
This work describes a new orientation method for semicrystalline poly(3-hexylthiophene) (P3HT) thin films, coupling nanorubbing and subsequent crystallization. Using the stylus of an atomic force microscope, we align the polymer chains on P3HT surfaces with a spatial and geometrical control of the oriented domains (nanorubbing). These chain-aligned structures can be made permanent thanks to the crystallization process, which propagates the orientation obtained at the surface to the bulk.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.