Isoindigo-based fluorinated low band gap polymers for environmentally stable field effect transistor

Abstract

Two isoindigo-based conjugated polymers, based on fluorinated elctron donor units (dithienyldifluorobenzothiadiazole(DT2FBT) and dithienyltetrafluorobenzene (DT4FBZ)), have been synthesized and their optical, electrochemical, morphological, and crystallinity features were evaluated. The combination of highly conjugated isoindigo moiety with fluorinated electron donor units induces high crystallinity of the derived polymers, resulting in p-type charge transport characteristics with high hole mobility exceeding 7.0 × 10−2 cm2 V−1 s−1. Furthermore, the low-lying energy levels due to the electron-deficient fluorinated electron donors allow not only effective electrical contact with the source/drain electrodes but also excellent ambient stability of the derived transistor devices, enabling the polymers to be promising candidates for the environmentally stable optoelectronics.