An international research team led by the Universities of Birmingham and Warwick has developed nanoribbons with tailored electronic properties, as reported in Nature Communications on 23 April.
The nanoribbons are built from chains of individual molecules using donor–acceptor (D–A) chemistry, where electron-donating and electron-accepting units are arranged in controlled sequences.
Researchers designed two special molecules (an electron donor and an electron acceptor), placed them on a gold surface in vacuum, and heated them to form nanoribbons. They created donor-only, acceptor-only, and mixed D–A ribbons.
Using advanced microscopes, they imaged individual molecules and measured electronic behavior within the ribbons.
Longer donor-only ribbons were better electron donors; longer acceptor-only ribbons were stronger electron acceptors. In mixed ribbons, properties depended on the precise sequence of D and A units.
A theoretical model was established to describe the relationship between subunit composition and electronic properties.
Applications
The advance could contribute to development of:
- Flexible organic electronics for smart clothing
- Ultra-small circuits for Internet of Things devices
- Bioelectronics for implants
- More efficient solar cells
- New types of sensors
- Quantum or molecular electronics
Statements
Professor Giovanni Costantini (University of Birmingham, corresponding author) stated that this is the first time nanoribbons have been built by directly combining electron donor and acceptor units, allowing control over electronic properties with atomic precision.
Davide Bonifazi (University of Vienna) stated that embedding donor–acceptor concepts into on-surface fabrication strategies enabled preparation of extended nanoribbon structures difficult to make in solution.
James Lawrence (formerly University of Warwick, now National University of Singapore) stated that building nanoribbons directly on a metal surface can produce perfectly defined structures, difficult to achieve with traditional chemistry.
Gabriele Sosso (University of Warwick) stated that capturing effects of the supporting surface and local environment will be key to guiding further development.
Next Steps
The researchers plan to apply the approach to design materials with targeted properties for organic electronics, bioelectronics, and photovoltaics.