Chlorinated Benzo[1,2-b:4,5-c']dithiophene-4,8-dione Polymer Donor: A Small Atom Makes a Big Difference.

ABSTRACT: The position of a chlorine atom in a charge carrier of polymer solar cells (PSCs) is important to boost their photovoltaic performance. Herein, two chlorinated D-A conjugated polymers PBBD-Cl-α and PBBD-Cl-β are synthesized based on two new building blocks (TTO-Cl-α and TTO-Cl-β) respectively by introducing the chlorine atom into α or β position of the upper thiophene of the highly electron-deficient benzo[1,2-b:4,5-c']dithiophene-4,8-dione moiety. Single-crystal analysis demonstrates that the chlorine-free TTO shows a π-π stacking distance (d _π-π) of 3.55 Å. When H atom at the α position of thiophene of TTO is replaced by Cl, both π-π stacking distance (d _π-π = 3.48 Å) and Cl···S distance (d _Cl-S = 4.4 Å) are simultaneously reduced for

SUBMITTER: Chao P 

PROVIDER: S-EPMC7887605 | biostudies-literature | 2021 Feb

REPOSITORIES: biostudies-literature