In addition to the power conversion efficiency (PCE) of polymer solar cells (PSCs), long-term stability is a critical requirement. In this study, a crosslinkable PM6-based polymer donor, PM6-X30, was developed by introducing photocrosslinkable side chains into the PM6 polymer backbone. The new PM6-X30 retained the fundamental properties of the high-performance PM6 backbone. The crosslinking reaction was induced under the mild condition of UV 365 nm irradiation for 10 min, forming a stable polymer network to lock the internal morphology of the active layer. The PSC fabricated with the crosslinked PM6-X30:Y6-BO active layer exhibited a high PCE of 12.33%. Subsequently, this device sustained more than 80% of its original PCE after thermal aging at 80 °C for 180 min, while the non-crosslinked device and the reference device based on PM6-X0 could only retain 27.7 and 42.9% of their PCE, respectively, under the same aging conditions. This work demonstrates a promising strategy for boosting the long-term stability of high-performance PSCs, even at a slight sacrifice of the maximum PCE.
Bibliographical noteFunding Information:
The authors acknowledge the financial support from the National Research Foundation of Korea (NRF-2019R1A6A1A11044070, 2020R1I1A1A01066897 and 2022R1A2B5B02001454). We are grateful to the Pohang Accelerator Laboratory (Pohang, Korea) for allowing us to conduct the grazing incidence X-ray diffraction measurements (GIWAXD), and the Institute for Basic Science (IBS, Korea) for allowing us to obtain nuclear magnetic resonance data (NMR, Ascend 500, Bruker). The Korea Basic Science Institute (Seoul) is acknowledged for the MALDI-TOF MS data.
© 2023 The Royal Society of Chemistry
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Materials Science(all)