Recent research has revealed a technique for producing graphene that deliberately incorporates structural defects to enhance its performance. This strategy could help advance several fields, including sensors, batteries and electronics.
Scientists from the University of Nottingham’s School of Chemistry, the University of Warwick and Diamond Light Source created a single-step approach that grows graphene-like films using a molecule called Azupyrene. The shape of this molecule closely resembles the type of defect the researchers wanted to introduce. Their findings were published recently in Chemical Science.
Why Imperfections Can Improve Graphene
David Duncan, Associate Professor from the University of Nottingham and one of the study’s lead authors, explains: “Our study explores a new way to make graphene, this super-thin, super-strong material is made of carbon atoms, and while perfect graphene is remarkable, it is sometimes too perfect. It interacts weakly with other materials and lacks crucial electronic properties required in the semiconductor industry.
“Usually defects in material are seen as problems or mistakes that reduce performance, we have used them intentionally to add functionality. We found the defects can make the graphene more “sticky” to other materials, making it more useful as a catalyst, as well as improving its capability of detecting different gasses for use in sensors. The defects can also alter the electronic and magnetic properties of the graphene, for potential applications in the semiconductor industry.”
Azupyrene Enables Precise Control of Defect Formation
Graphene is normally built from a repeating pattern of six carbon atoms arranged in a flat ring. The defect targeted in this research consists of neighboring 5 and 7 atom rings. Azupyrene naturally contains this type of irregular ring pattern, making it an ideal starting molecule. By using Azupyrene to grow the graphene films, the team achieved a high concentration of this specific defect. Adjusting the temperature during the growth phase allowed the researchers to fine-tune how many defects appeared in the final material.
Researchers at the Graphene Institute in Manchester also showed that the resulting graphene could be transferred onto a variety of surfaces while keeping the engineered defects intact, an important step toward integrating these films into real devices.
International Collaboration and Advanced Tools Reveal Atomic Behavior
The project relied on a broad set of advanced techniques and involved teams from the UK, Germany and Sweden. Researchers used high-resolution microscopy and spectroscopy at Diamond Light Source in Oxfordshire and at MAX IV in Sweden, along with the UK national supercomputer ARCHER2. These tools enabled them to examine the atomic structure of the defective graphene, confirm the presence of the engineered defects and determine how they influenced the material’s chemical and electronic behavior.
Professor Reinhard Maurer from the Department of Chemistry at the University of Warwick states: “By carefully choosing the starting molecule and the growth conditions, we’ve shown it’s possible to grow graphene in which imperfections can be introduced in a more controlled way. We characterize the signatures of these imperfects by bringing together atomic-scale imaging, spectroscopy, and computational simulation.”
“This study is a testament to what can be achieved through international collaboration and the integration of diverse scientific expertise,” said Dr. Tien-Lin Lee from Diamond Light Source. “By combining advanced microscopy, spectroscopy, and computational modelling across institutions in the UK, Germany, and Sweden, we were able to uncover the atomic-scale mechanisms behind defect formation in graphene, something no single technique or team could have achieved alone.”
