Three n-type semiconducting polymers, P-0, P-50, and P-75 are investigated, in which the lactone group density were maximized by increasing the benzene content from 0% benzene (P-0), to 50% (P-50), and 75% (P-75), to enable co-planar polymers with deep-lying LUMO energy level. As a result, the polymer of P-75 exhibits a good polaron stability in air, allowing a high performing organic thermoelectrics with electrical conductivities (σ) of up to 12 S cm−1 and high power factor (PF) up to 13.2 μWm−1 K−2. These results suggest the significance of chemical design and provide new guidelines towards high performing n-type OTE devices.
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