Balancing Solubility and Thermoelectric Performance in it-Extended Poly(benzimidazoanthradiisoquinolinedione) Ladder-Type Conjugated Polymer

Herein, we report a new n-type ladder-type conjugated polymer, d i c h l o r i n a t e d poly(benzimidazoanthradiisoquinolinedione) (Cl2-BAL), that possesses a slightly twisted polymer backbone and a preferred edge on orientation. Upon n-doping, its maximum electrical conductivity and power factor in thermoelectric devices reached 1.1 +/- 0.07 S cm-1 and 3.52 +/- 0.37 mu W m-1 K-2, respectively, and is almost on par with the best performing ladder-type conjugated polymer BBL. As compared to our previously reported tetrachlorinated analogue Cl4-BAL, our results demonstrate that the chlorine atoms can influence not only the torsion angle but also the orientation and N-N stacking, which in turn dramatically affects its performance.

Automated summary

In this study, a new n-type ladder-type conjugated polymer, dichlorinated poly(benzimidazoanthradiisoquinolinedione) (Cl2-BAL), with a slightly twisted polymer backbone and a preferred edge on orientation, was reported. Upon n-doping, its maximum electrical conductivity and power factor in thermoelectric devices reached 1.1 +/- 0.07 S cm-1 and 3.52 +/- 0.37 mu W m-1 K-2, respectively, which is comparable to the best performing ladder-type conjugated polymer BBL. Chlorine atoms not only influence the torsion angle but also the orientation and N-N stacking, significantly affecting the performance as demonstrated by comparing with the previously reported tetrachlorinated analogue Cl4-BAL.