Siloxane Side Chains: A Universal Tool for Practical Applications of Organic Field-Effect Transistors

To systematically address the intriguing question of how siloxane termini of the side chains relative to alkyl-terminal groups affect the various inherent properties of conjugated polymers—including optical, electrical, and morphological characteristics—we have synthesized model polymers (PDPPTT-R TG and PDPPTT-Si TG, together with an accompanying reference PDPPTT-ref) containing an identical backbone yet possessing different terminal groups. In order to fairly compare the end functionalities by eliminating molecular weight ( M n ) and polydispersity index (PDI) variations that may act as complicating factors, the polymers used in this study have been controlled to have similar M n and PDI by carefully optimizing the catalyst system and reaction conditions. Although the molecular packing and orientation behaviors of PDPPTT-R TG and PDPPTT-Si TG are very different from each other, both po…