Molecular doping is a powerful tool to tune the thermoelectric (TE) properties of solution-processed semiconductors. In this work, we prepared a binary composite and effectively doped both of its constituents, that is, naphthalene diimide–bithiophene copolymers (PNDI2OD-T2) and single-walled carbon nanotubes (SWCNTs), by a 1H-benzimidazole derivative (N-DMBI). The doped composites show an n-type character and an in-plane TE figure of merit (ZT), exceeding the values obtained with the doped polymers. The use of SWCNTs consistently results in a higher σ with a maximum value above 102 S/cm, resulting in the highest power factor of 18.1 μW/mK2 for an SWCNT loading of 45.5 wt %. Furthermore, an SWCNT content up to 9 wt % does not compromise the low thermal conductivity of the polymer matrices, leading to a ZT value of 0.0045. The n-type composites show good solution processability and relatively stable Seebeck coefficients upon air exposure for 8 months.
|Original language||English (US)|
|Journal||ACS Applied Materials & Interfaces|
|State||Published - Dec 29 2020|
Bibliographical noteKAUST Repository Item: Exported on 2021-01-04
Acknowledged KAUST grant number(s): CRG2018-3737., OSR-2018-CARF/CCF-3079, OSR-CRG2018-3737
Acknowledgements: This report is based upon the work supported by the King Abdullah University of Science and Technology (KAUST) Office of Sponsored Research (OSR) under Award no. OSR-CRG2018-3737. A.S. greatly acknowledges the financial support from King Abdullah University of Science and Technology (KAUST) award OSR-2018-CARF/CCF-3079.