Developing intrinsically self-healable semiconducting polymers is particularly important for realizing stretchable electronic devices which can spontaneously recover their mechanical damage. We synthesized a series of conjugated donor polymers (PTO2-tm series) functionalized with a thymine group at the terminal of the side chain. Bulk heterojunction (BHJ) films of PTO2-tm polymers blended with an IT-4F acceptor achieved power conversion efficiencies up to 11.9% from the BHJ-based organic photovoltaics, which are comparable with that of unfunctionalized PTO2 and, however, exhibited much improved stretchability by virtue of stress dissipation in the BHJ films during mechanical deformation. More importantly, the corresponding BHJ film prepared with a melamine additive efficiently recovered their packing structures after being mechanically damaged by stretching. As a result, reversible multiple hydrogen bonding of the melamine molecule with thymine in PTO2-tm polymers showed much improved crack onset strain and maximum recoverable strain compared with PTO2.
Bibliographical noteFunding Information:
This work was supported by the KIST institutional internal program, Basic Research in Science & Engineering Program of the National Research Foundation (NRF) of Korea (NRF-2019R1A2C2088022 and 2020R1F1A1054198), National R&D Program through the NRF of Korea funded by Ministry of Science and ICT (NRF-2020M3H4A1A02084910) and Nano Future Material Technology Development Program through the NRF of Korea funded by the Ministry of Science and ICT (NRF-2020M3H4A3081817).
© 2021 American Chemical Society.
ASJC Scopus subject areas
- Organic Chemistry
- Polymers and Plastics
- Inorganic Chemistry
- Materials Chemistry