Cracking in polymer substrates for flexible electronic devices and its mitigation
Mechanical reliability plays a critical role in determining the durability of flexible electronic devices because of the significant mechanical stresses they experience during manufacturing and operation. Many such devices are built on sheets comprising stiff transparent-conducting oxide (TCO) electrode films on compliant polymer substrates, and it is generally assumed that the high-toughness polymer substrates do not crack. Contrary to this assumption, here we show extensive cracking in the polymer substrates during bending of a variety of TCO/polymer sheets, and a device example — flexible perovskite solar cells. Such substrate cracking, which compromises the overall mechanical integrity of the entire device, is driven by the amplified stress-intensity factor caused by the elastic mismatch at the film/substrate interface. To mitigate this substrate cracking, an interlayer-engineering approach is designed and experimentally demonstrated. This approach is potentially applicable to myriad flexible electronic devices, with stiff films on compliant substrates, for improving their durability and reliability.
Authors
- Nitin P. Padture (ORCID: https://orcid.org/0000-0001-6622-8559)
- Aldo Di Carlo (ORCID: https://orcid.org/0000-0001-6828-2380)
- Conrad A. Kocoj (ORCID: https://orcid.org/0000-0003-2386-2896)
- Francesca Brunetti (ORCID: https://orcid.org/0000-0003-2287-4545)
- Madhuja Layek (ORCID: https://orcid.org/0000-0002-2137-0006)
- Cristina López-Pernía (ORCID: https://orcid.org/0000-0002-5493-1914)
- Peijun Guo (ORCID: https://orcid.org/0000-0001-5732-7061)
- Sayaka Kochiyama (ORCID: https://orcid.org/0000-0002-5709-1527)
- Erica Magliano (ORCID: https://orcid.org/0000-0001-9494-515X)
- Haneesh Kesari (ORCID: https://orcid.org/0000-0001-9761-5754)
- Anush Ranka
- Subra Suresh
- David C. Paine
- Alicia M. Chandler
Institutions
- University of Rome Tor Vergata (IT)
- Brown University (US)
- Yale University (US)
- Institute of Structure of Matter (IT)
Publication Details
- Journal
- npj Flexible Electronics
- Published
- 2025-08-22
- DOI
- https://doi.org/10.1038/s41528-025-00470-z
- Citations
- 5
- Primary Topic
- Electronic Packaging and Soldering Technologies
- Type
- article
- Field-Weighted Citation Impact
- 2.92
Funders
- National Science Foundation
- U.S. Department of Energy
- Yale University
- Brown University
- European Commission
- Office of Energy Efficiency and Renewable Energy
- Office of Naval Research
- Division of Materials Research
- Division of Chemical, Bioengineering, Environmental, and Transport Systems
- Basic Energy Sciences
- Solar Energy Technologies Office
- Office of Energy Efficiency
- HORIZON EUROPE European Innovation Council