Electron-Deficient and Quinoid Central Unit Engineering for Unfused Ring-Based A 1 –D–A 2 –D–A 1 -Type Acceptor Enables High Performance Nonfullerene Polymer Solar Cells with High V oc and PCE Simultaneously

Chao Zhang, Xin Song, Kai-Kai Liu, Ming Zhang, Jianfei Qu, Can Yang, Gui-Zhou Yuan, Asif Mahmood, Feng Liu, Feng He, Derya Baran, Jin-Liang Wang

Research output: Contribution to journalArticlepeer-review

32 Scopus citations

Abstract

Here, a pair of A1 -D-A2 -D-A1 unfused ring core-based nonfullerene small molecule acceptors (NF-SMAs), BO2FIDT-4Cl and BT2FIDT-4Cl is synthesized, which possess the same terminals (A1 ) and indacenodithiophene unit (D), coupling with different fluorinated electron-deficient central unit (difluorobenzoxadiazole or difluorobenzothiadiazole) (A2 ). BT2FIDT-4Cl exhibits a slightly smaller optical bandgap of 1.56 eV, upshifted highest occupied molecular orbital energy levels, much higher electron mobility, and slightly enhanced molecular packing order in neat thin films than that of BO2FIDT-4Cl. The polymer solar cells (PSCs) based on BT2FIDT-4Cl:PM7 yield the best power conversion efficiency (PCE) of 12.5% with a Voc of 0.97 V, which is higher than that of BO2FIDT-4Cl-based devices (PCE of 10.4%). The results demonstrate that the subtle modification of A2 unit would result in lower trap-assisted recombination, more favorable morphology features, and more balanced electron and hole mobility in the PM7:BT2FIDT-4Cl blend films. It is worth mentioning that the PCE of 12.5% is the highest value in nonfused ring NF-SMA-based binary PSCs with high Voc over 0.90 V. These results suggest that appropriate modulation of the quinoid electron-deficient central unit is an effective approach to construct highly efficient unfused ring NF-SMAs to boost PCE and Voc simultaneously.
Original languageEnglish (US)
Pages (from-to)1907681
JournalSmall
DOIs
StatePublished - May 7 2020

Bibliographical note

KAUST Repository Item: Exported on 2020-10-01
Acknowledgements: C.Z. and X.S. contributed equally to this work. This work was financially supported by the grants from the National Natural Science Foundation of China (Nos. 21672023, 21971014, and 21472012) and the National Key Research and Development Program of China (2018YFA0901800). J.-L.W. was supported by the Thousand Youth Talents Plan of China and BIT Teli Young Fellow Recruitment Program. The authors thank Analysis & Testing Center, Beijing Institute of Technology for NMR experiments. J.-L.W. and C.Z. thank Can Yang (Beijing Institute of Technology) for the synthesis of difluorobenzoxadiazole core unit and Gui-Zhou Yuan (Beijing Institute of Technology) for the synthesis of IC2Cl end group. The authors thank Prof. Yapei Wang (Renmin University of China) for TGA experiment. The authors thank Qi Li and Zixuan Huang (Beijing Institute of Technology) for the helping on the synthesis or purification of precursors. X-ray data were acquired at beamlines 7.3.3 at the Advanced Light Source (ALS) in Berkeley National Lab, which is supported by the U.S. Department of Energy. J.-L.W. and C.Z. thank Kai-Kai Liu and Shi-Sheng Wan (Beijing Institute of Technology) for the helping on original manuscript preparation and data interpretation

Fingerprint

Dive into the research topics of 'Electron-Deficient and Quinoid Central Unit Engineering for Unfused Ring-Based A 1 –D–A 2 –D–A 1 -Type Acceptor Enables High Performance Nonfullerene Polymer Solar Cells with High V oc and PCE Simultaneously'. Together they form a unique fingerprint.

Cite this