Synthesis and Characterization of Thiophene-Containing Naphthalene Diimide n-Type Copolymers for OFET Applications

Naphthalene diimide (NDI) copolymers are attractive n-type materials for use in organic electronic devices. Four highly soluble NDI polymers are presented—each differing only in the thiophene content comprising the material. Electron mobilities as high as 0.076 cm 2 V −1 s −1 for the novel material PNDI-3Th are reported. Polymer crystallinity and general macromolecular order are shown to effectively improve by increasing the number of thiophene units within the polymer backbone. The structure−property relationship of NDI−thiophene copolymers is presented and discussed as it pertains to organic field effect transistor (OFET) performance.