High-Performance Field-Effect Transistors Fabricated with Donor–Acceptor Copolymers Containing S···O Conformational Locks Supplied by Diethoxydithiophenethenes

Abstract

Constructing planar π-conjugated backbone is of critical importance for polymeric semiconductors to obtain high charge carrier mobility. In this regard, suitable introduction of noncovalent interactions is one of useful approaches. Herein, we report a series of donor–acceptor copolymers based on diethoxydithiophenethene (EDTE), namely PEDTEn (n = 1, 2, and 3), containing multiple O···H–C and S···O conformational locks, where the latter ones are supplied by the EDTE units. PEDTEn owns planar conjugated backbones with suitable HOMO energy levels (ca. – 5.20 eV) and strong absorption behaviors along with enhanced solution processability. High-performance field-effect transistors based on the copolymers exhibited a high hole mobility of up to 5.37 cm2 V–1 s–1, which is among the highest values of semiconducting polymers based on the concept of conformational locks. AFM and GIXRD experiments reveal that PEDTEn could form crystalline and close packing thin films with a π–π stacking distance of down to 3.78 Å.