Controlling Molecular Mass of Low-Band-Gap Polymer Acceptors for High-Performance All-Polymer Solar Cells

By Wei Wang, Qian Wu, Rui Sun, Jing Guo, Yao Wu, Mumin Shi, Wenyan Yang, Hongneng Li, J. Min. 2020

220 citations recorded by the source corpus.

Summary Recent advances in the development of polymer acceptors and the investigation of molecular mass have boosted the power conversion efficiency (PCE) of all-polymer solar cells (all-PSCs) to approximately 11%. Here, a fused-aromatic-ring-constructed polymer acceptor PYT (Poly[(2,2′-((2Z,2′Z)-((12,13-bis(2-octyldodecyl)-3,9-diundecyl-12,13-dihydro[1,2,5]thiadiazolo[3,4e]thieno[2″,3″:4′,5′]thieno[2′,3′:4,5]pyrrolo[3,2-g]thieno[2′,3′:4,5]thieno[3,2-b]-indole-2,10-diyl)bis(methanylylidene))bis(3-oxo-2,3-dihydro-1H-indene-2,1-diylidene)) dimalononitrile-alt-2,5-thiophene)]) is reported, while a series of PYT polymers with different molecular masses (designated as PYTL, PYTM, and PYTH) are prepared to fine-tune the molecular crystallinity and miscibility. Benefiting from the advantages of PYT series, which possess broad absorption with a narrow band of 1.40–1.44 eV and high absorption coefficients of over 1.00 × 105 cm−1, we investigated the blend miscibility and device performance of all-PSCs based on a wide-band-gap polymer donor, PM6. The PYTM-based all-PSCs exhibit an excellent PCE of 13.44%, outperforming those with PYTL (12.55%) and PYTH (8.61%). Our results provide insight into polymer acceptor backbone and molecular mass and suggest guidelines to rationally select polymers for all-PSCs.

Subfields: Electrical and Electronic Engineering, Polymers and Plastics

View Paper: https://www.semanticscholar.org/paper/51fd09afa0242439999460f660011052612bcf30