A Facile Route to Large-Scale Hierarchically Structured Conjugated Polymer Assemblies with Enhanced Electrical Conductivity

By subjecting a drying droplet containing conjugated homopolymers or all-conjugated diblock copolymer to a judiciously designed geometry consisting of a cylinder situated on a flat substrate (i.e., cylinder-on-flat geometry), a set of highly ordered straight or wavy stripes at the microscopic scale over a large area were yielded, in which each microscopic stripe was composed of bundles of nanofibers or nodule-like nanodomains (i.e., forming hierarchical assemblies). These hierarchical patterns of conjugated homopolymers and all-conjugated diblock copolymer exhibited good electrical properties. Quite intriguingly, the crystallinity of the as-prepared assemblies of all-conjugated diblock copolymer was largely improved after the solvent vapor annealing, resulting in four times increase in electric conductivity. This facile, scalable deposition technique based on controlled evaporative self-assembly renders the crafting of hierarchically structured semicrystalline conjugated optoelectronic materials, and may provide a paradigm to develop high-performance electronic devices in a simple and controllable manner.