Modulating the nanoscale morphology on carboxylate-pyrazine containing terpolymer toward 17.8% efficiency organic solar cells with enhanced thermal stability
Journal article, 2022

It had been commonly accepted in the organic photovoltaic (OPV) community that subtle variations in the molecular structure of active layer materials would cause profound impacts on their aggregating structure and blend morphology and therefore the performance of such polymer solar cells (PSCs). Herein, we employed an electron-deficient building block 3,6-dithiophenyl-2-carboxylate pyrazine (DTCPz) for constructing one series of promising donor terpolymers of PMZ1, PMZ2, and PMZ3, respectively, gaining their relatively lower-lying highest occupied molecular orbital (HOMO) energy levels, more closed π-π stacking and enhanced crystallinity in thin films, and lower miscibility with acceptor Y6, in comparison with their parent polymer counterpart (namely PM6). Reaching DTCPz moieties up to 20% (mol/mol%) in its terpolymer composition, the resulting polymer (PMZ2) achieved more favorable phase separation with improved exciton dissociation, and charge transport and extraction. As a result, an outstanding fill factor of 77.2% and a promising power conversion efficiency of 17.8 % was achieved. Moreover, the corresponding device shows better thermal stability over the PM6-based one. This work suggests a facile method for significantly improving the thin film morphology of the active-layer materials via fine-tuning the chemical structure of electron-deficient units on the backbone of the wide bandgap donor polymer, therefore achieving enhanced photovoltaic performance and thermal stability for practical applications.

Random ternary polymerization

Pyrazine

Non-fullerene

Wide bandgap

Organic solar cells

Author

Jingnan Wu

Aalborg University

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Shandong University

Soochow University

Xia Guo

Shandong University

Soochow University

Minghai Xiong

Soochow University

Xinxin Xia

Chinese University of Hong Kong

Qi Li

Chalmers, Microtechnology and Nanoscience (MC2), Electronics Material and Systems

Jin Fang

Soochow University

Xin Yan

Soochow University

Qi Liu

Soochow University

Xinhui Lu

Chinese University of Hong Kong

Ergang Wang

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Donghong Yu

Aalborg University

Maojie Zhang

Shandong University

Soochow University

Chemical Engineering Journal

1385-8947 (ISSN)

Vol. 446 137424

Subject Categories

Polymer Chemistry

Inorganic Chemistry

Materials Chemistry

DOI

10.1016/j.cej.2022.137424

More information

Latest update

6/23/2022