Carbon nanotubes assisting interchain charge transport in semiconducting polymer thin films towards much improved charge carrier mobility

Abstract

Conjugated polymers attracted much attention in the past few decades due to their wide applications in various optoelectronic devices and circuits. The charge transport process in conjugated polymers mainly occurs in the intrachain and interchain parts, where the interchain charge transport is generally slower than intrachain transport and may slow down the whole charge transport properties. Aiming at this issue, herein we employ semiconducting single-walled carbon nanotubes (s-SWNTs) as efficient charge-transporting jointing channels between conjugated polymer chains for improving the charge transport performance. Taking the typical conjugated polymer, ploy-N-alkyl-diketopyrrolopyrrole- dithienylthieno[3,2-b]thiophene (PDPP-TT) as an example, polymer thin film transistors (PTFTs) based on the optimized blended films of PDPP-TT/s-SWNTs exhibit an obviously increasing device performance compared with the devices based on pure PDPP-TT films, with the hole and electron mobility increased from 2.32 to 12.32 cm 2 V −1 s −1 and from 2.02 to 5.77 cm 2 V −1 s −1 , respectively. This result suggests the importance of forming continuous conducting channels in conjugated polymer thin films, which can also be extended to other polymeric electronic and optoelectronic devices to promote their potential applications in large-area, low-cost and high performance polymeric electronic devices and circuits.