Single-Crystal Poly[4-(4,4-dihexadecyl-4H-cyclopenta[1,2-b:5,4-b′]dithiophen-2-yl)-<i>alt</i>-[1,2,5]thiadiazolo[3,4-<i>c</i>]pyridine] Nanowires with Ultrahigh Mobility

Abstract

We fabricated single-crystal poly[4-(4,4-dihexadecyl-4H-cyclopenta[1,2-b:5,4-b′]-dithiophen-2-yl)-alt-[1,2,5]thiadiazolo-[3,4-c]pyridine] (PCDTPT) nanowires with ultrahigh mobility using a liquid-bridge-mediated nanotransfer molding method. The structural analysis of the single-crystal PCDTPT nanowires reveals that PCDTPT crystals have a triclinic structure, and the nanowires grow parallel to PCDTPT backbone chains, which provide important insights into its intrinsic charge transport. The single-crystal PCDTPT nanowire exhibits a superior charge carrier mobility of 72.94 ± 18.02 cm2 V–1 s–1 (maximum mobility up to 92.64 cm2 V–1 s–1), which is a record high value among conjugated polymers to date. In the single-crystal PCDTPT nanowire, the backbone chains in the linear structure along the nanowire growth axis lead to strong backbone delocalization, resulting in highly conductive polymer backbones and a drastic increase in charge carrier mobility. In addition, the single-crystal PCDTPT nanowire shows good environmental stability under air conditions compared to small-molecule organic semiconductors.