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Vol. 17 (2025)

Achieving 20% Toluene-Processed Binary Organic Solar Cells via Secondary Regulation of Donor Aggregation in Sequential Processing

https://doi.org/10.1007/s40820-025-01715-2
Yufei Wang
College of New Materials and New Energies, Shenzhen Technology University, Shenzhen 518118, People’s Republic of China
Chuanlin Gao
College of New Materials and New Energies, Shenzhen Technology University, Shenzhen 518118, People’s Republic of China
Wen Lei
College of Cyber Security, Jinan University, Guangzhou 511443, People’s Republic of China
Tao Yang
Future Technology School, Shenzhen Technology University, Shenzhen 518118, People’s Republic of China
Zezhou Liang
Key Laboratory for Physical Electronics and Devices of the Ministry of Education and Shaanxi Key Lab of Photonic, Technique for Information, School of Electronics Science and Engineering, Faculty of Electronic and Information Engineering, Xi’an Jiaotong University, Xi’an 710049, People’s Republic of China
Kangbo Sun
College of New Materials and New Energies, Shenzhen Technology University, Shenzhen 518118, People’s Republic of China
Chaoyue Zhao
College of New Materials and New Energies, Shenzhen Technology University, Shenzhen 518118, People’s Republic of China
Lu Chen
College of New Materials and New Energies, Shenzhen Technology University, Shenzhen 518118, People’s Republic of China
Liangxiang Zhu
College of New Materials and New Energies, Shenzhen Technology University, Shenzhen 518118, People’s Republic of China
Haoxuan Zeng
College of New Materials and New Energies, Shenzhen Technology University, Shenzhen 518118, People’s Republic of China
Xiaokang Sun
Hoffmann Institute of Advanced Materials, Shenzhen Polytechnic University, Shenzhen 518055, People’s Republic of China
Bin He
College of New Materials and New Energies, Shenzhen Technology University, Shenzhen 518118, People’s Republic of China
Hanlin Hu
Hoffmann Institute of Advanced Materials, Shenzhen Polytechnic University, Shenzhen 518055, People’s Republic of China
Zeguo Tang
College of New Materials and New Energies, Shenzhen Technology University, Shenzhen 518118, People’s Republic of China
Mingxia Qiu
College of New Materials and New Energies, Shenzhen Technology University, Shenzhen 518118, People’s Republic of China
Shunpu Li
College of New Materials and New Energies, Shenzhen Technology University, Shenzhen 518118, People’s Republic of China
Peigang Han
College of New Materials and New Energies, Shenzhen Technology University, Shenzhen 518118, People’s Republic of China
Guangye Zhang
College of New Materials and New Energies, Shenzhen Technology University, Shenzhen 518118, People’s Republic of China

Corresponding Author: Guangye Zhang

zhangguangye@sztu.edu.cn

Nano-Micro Letters, Vol. 17 (2025), Article Number: 206

Abstract

Sequential processing (SqP) of the active layer offers independent optimization of the donor and acceptor with more targeted solvent design, which is considered the most promising strategy for achieving efficient organic solar cells (OSCs). In the SqP method, the favorable interpenetrating network seriously depends on the fine control of the bottom layer swelling. However, the choice of solvent(s) for both the donor and acceptor have been mostly based on a trial-and-error manner. A single solvent often cannot achieve sufficient yet not excessive swelling, which has long been a difficulty in the high efficient SqP OSCs. Herein, two new isomeric molecules are introduced to fine-tune the nucleation and crystallization dynamics that allows judicious control over the swelling of the bottom layer. The strong non-covalent interaction between the isomeric molecule and active materials provides an excellent driving force for optimize the swelling-process. Among them, the molecule with high dipole moment promotes earlier nucleation of the PM6 and provides extended time for crystallization during SqP, improving bulk morphology and vertical phase segregation. As a result, champion efficiencies of 17.38% and 20.00% (certified 19.70%) are achieved based on PM6/PYF-T-o (all-polymer) and PM6/BTP-eC9 devices casted by toluene solvent.


Highlights:
1 Isomeric molecules are introduced to fine-tune the secondary nucleation process of the donor underlayer.
2 Binary organic solar cell processed with non-halogen solvent shows a champion efficiency of 20.0% (certified 19.7%).
3 Mechanism of the film formation processes and the sequential processing community about solvent design rules are proposed.

Keywords

Organic solar cells Non-halogen solvent Sequential processing Secondary nucleation Stability
Wang, Yufei, Chuanlin Gao, Wen Lei, Tao Yang, Zezhou Liang, Kangbo Sun, Chaoyue Zhao, Lu Chen, Liangxiang Zhu, Haoxuan Zeng, Xiaokang Sun, Bin He, Hanlin Hu, Zeguo Tang, Mingxia Qiu, Shunpu Li, Peigang Han, and Guangye Zhang. 2025. “Achieving 20% Toluene-Processed Binary Organic Solar Cells via Secondary Regulation of Donor Aggregation in Sequential Processing”. Nano-Micro Letters 17 (April):206. https://doi.org/10.1007/s40820-025-01715-2.
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