Diketopyrrolopyrrole (DPP)-based copolymers, including poly[2,5-bis(2-octyldodecyl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione-alt-(E)-1,2-di(2,2’-bithiophen-5-yl)ethene (PDDBE) and poly[2,5-bis(2-octyldodecyl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione-alt-(E)-1,2-bis(6-hexylthieno[3,2-b]thiophene-2-yl)ethene (PDTTE), were synthesized by alternating a DPP-derivative acceptor (A) block with different donor (D) blocks, such as (E)-1,2-di(2,2’-bithiophen-5-yl)ethene and (E)-1,2-bis(6-hexylthieno[3,2-b]thiophene-2-yl)ethene. These copolymers had drastically different crystal structures on polymer-grafted SiO2 dielectrics. Multiple-layered crystallites of PDDBE had a long-range, π-conjugated extension but a wide conjugated distance, d(010), of 3.90 Å. Nanorod-percolated agglomerates of PDTTE had a much shorter d(010) of 3.71 Å, originating from the alternating structures of the DPP derivative with slightly different D blocks. The corresponding crystallites yielded a wide range of mobilities from 0.01 to 1.40 cm2V-1s-1 in the OFETs.
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