Recently, with the increasing surge of the internet of Things, flexible electronics based on electronic circuitry on flexible substrates have attracted a lot of attention for their great potential in many important wearable electronic applications. Polymer thin-film transistors (PTFTs) where synthesized polymer semiconductor is served as an active layer are regarded as a suitable basic switching device for flexible electronics, owing to the inherent mechanical flexibility of polymer films. PTFTs for flexible electronic circuitry can be truly achieved when the development of complimentary polymer semiconductor set, including both p-type and n-type semiconductors is prepared. In this regard, the control of charge-transfer characteristics in the semiconducting polymers with rational molecular design is essential.<br/>In this study, we have found that the conversion of the charge-transfer characteristics in benzodithiophene-thiadiazoloquinoxaline (BDT-TAQ) based semiconducting copolymer is possible by adding the trifluoromethyl group. Figure 1(a) shows the BDT-TAQ based donor (D) – acceptor (A) type semiconducting copolymer, wherein BDT moiety is used for donor part and TAQ block is worked as accepter unit, and the device structure used in this study. As shown in Figure 1(b) and 1(c), the BDT-TAQ based PTFT clearly shows ambipolar characteristics which allow both electron and hole to transport in the semiconducting polymer channel, while the PTFTs employing the BDT-TAQ-CF<sub>3</sub> as an active layer exhibit the only n-type characteristics. This preliminary results indicated that the attachment of the trifluoromethyl group can switch the charge characteristics of D-A type semiconducting polymer from ambipolar to n-type.

Conversion of charge-transfer characteristics in semiconducting copolymer by adding trifluoromethyl group to the acceptor unit

254th National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.