Template-mediated nano-crystallite networks in semiconducting polymers

Abstract

Unlike typical inorganic semiconductors with a crystal structure, the charge dynamics of pi-conjugated polymers (pi-CPs) are severely limited by the presence of amorphous portions between the ordered crystalline regions. Thus, the formation of interconnected pathways along crystallites of pi-CPs is desired to ensure highly efficient charge transport in printable electronics. Here we report the formation of nano-crystallite networks in pi-CP films by employing novel template-mediated crystallization (TMC) via polaron formation and electrostatic interaction. The lateral and vertical charge transport of TMC-treated films increased by two orders of magnitude compared with pristine pi-CPs. In particular, because of the unprecedented room temperature and solution-processing advantages of our TMC method, we achieve a field-effect mobility of 0.25 cm(2) V-1 s(-1) using a plastic substrate, which corresponds to the highest value reported thus far. Because our findings can be applied to various pi-conjugated semiconductors, our approach is universal and is expected to yield high-performance printable electronics.