| Affiliation: | 1. State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022 P. R. China University of Science and Technology of China, Hefei, 230026 P. R. China;2. State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022 P. R. China;3. Key Laboratory of UV-Emitting Materials and Technology, Northeast Normal University, Ministry of Education, Changchun, 130024 P. R. China |
| Abstract: | Typical n-type conjugated polymers are based on fused-ring electron-accepting building blocks. Herein, we report a non-fused-ring strategy to design n-type conjugated polymers, i.e. introducing electron-withdrawing imide or cyano groups to each thiophene unit of a non-fused-ring polythiophene backbone. The resulting polymer, n-PT1 , shows low LUMO/HOMO energy levels of −3.91 eV/−6.22 eV, high electron mobility of 0.39 cm2 V−1 s−1 and high crystallinity in thin film. After n-doping, n-PT1 exhibits excellent thermoelectric performance with an electrical conductivity of 61.2 S cm−1 and a power factor (PF) of 141.7 μW m−1 K−2. This PF is the highest value reported so far for n-type conjugated polymers and this is the first time for polythiophene derivatives to be used in n-type organic thermoelectrics. The excellent thermoelectric performance of n-PT1 is due to its superior tolerance to doping. This work indicates that polythiophene derivatives without fused rings are low-cost and high-performance n-type conjugated polymers. |
