Synthesis and characterization of conjugated polymers based on chlorinated isoindigo for organic electronics

Abstract

Organic electronics have attracted tremendous interest due to their solution processability and mechanical flexibility. Research on new semiconducting materials becomes more important to improve performance of organic electronic devices. One of the useful methods is introducing halogen atoms to molecular structure. This strategy can enhance electron mobility and ambient stability due to lower HOMO and LUMO energy levels caused from strong electron-withdrawing property of halogen atoms. Among others, chlorine atom can be easily applied by simple modification into polymer molecules compared to fluorine atom. Also, chlorinated polymers showed comparable device performance with fluorinated polymers. In this study, alternating copolymers were synthesized by using isoindigo and different donor moieties, bithiophene and thienylenevinylene, via Stille polymerization. We characterized these polymers and fabricated organic thin film transistor (OTFT) and organic photovoltaic device (OPV).