Synthesis and properties of indigo based donor-acceptor conjugated polymers

摘要

Indigo is for the first time used as a building block to construct polymer semiconductors for organic thin film transistors (OTFTs). Two donor-acceptor polymers using indigo as the acceptor and bithiophene as the donor are synthesized via Stille coupling polymerization. Two types of acyl groups, 2-hexldecanoyl (for polymer PI) and 2-octyldodecanoyl (for polymer P2), are utilized as solubilizing side chains. These polymers possess very deep highest-occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels, due to the strong electron accepting capability of the indigo moiety. In OTFT devices, characteristic n-type semiconductor performance with electron mobility of up to ~10~(-3) cm~2 V~(-1) s~(-1) is observed.