Thermoelectric Properties of a Family of Benzodifuranone‐Based Conjugated Copolymers in Oriented Thin Films Doped Sequentially With NDMBI‐H

Abstract This study demonstrates the possibility to enhance thermoelectric properties of n‐type benzodifuranone‐based copolymers using a combination of polymer orientation (using high temperature rubbing) and sequential doping with the dopant N‐DMBI‐H. It focuses on the impact of the side chain length and the chemical nature of the comonomer (thiophene vs furan) on the efficacy of this methodology that preserves the facile solution‐processability of this polymer family and enables effective sequential doping without a thermal activation step. The combination of high temperature rubbing and thermal annealing helps reach a high orientation of the copolymers with the thiophene comonomer regardless of the length of the side chains whereas the furan‐based polymer is marginally aligned. The high orientation of thiophene‐based copolymers results in a strong improvement of electrical conductivity and power factors reaching up to 9.8 ± 1.6 S cm −1 and 8 ± 3 µW m −1. K 2 , respectively.