Thermoelectric n-type Polymers: design, processing and structure – THERMOPOLYS

Thermoelectric (TE) materials have the capability to convert heat to electricity. Doped conjugated polymers (CPs) have emerged as promising materials since they are light, flexible, easy to process and can be operated at low temperatures. Efficient p-doped and n-doped CPs are required to build TE generators. Despite significant progress made on TE CPs in the last decade, doped n-type CPs still show modest TE performances and stabilities. This project explores two innovative strategies for the fabrication of new stable and efficient n-type thermoelectric polymers. The first approach combines the original synthesis of new n-type full-acceptor polymers and the implementation of orientation/crystallization and controlled doping methods, already successfully explored on p-type polymers, in order to optimize the structures and TE properties of polymer thin films. The second approach exploits the p--> n Seebeck polarity switch observed when a p-type alternating donor-acceptor copolymer is strongly doped by an oxidant, with the objective of identifying the macromolecular parameters influencing this polarity inversion as well as the underlying physical mechanism.
Finally, this project aims at obtaining new n-type TE polymers with power factors higher than 500 µW/mK2.