Researchers Find Graphene Ribbons Mimic Semiconductor Materials

September 10, 2020 by Antonio Anzaldua Jr.

Physicists and chemists from the Swedish Universities of Basel and Bern have produced the first porous graphene ribbons in which specific carbon atoms in the crystal lattice are replaced with nitrogen atoms.

The University of Bern’s Chemistry and Biochemistry department has focused its research efforts on electrochemistry, novel materials, and pharmaceuticals. Dr. Shi-Xia Liu is responsible for researching various methods of designing materials with controllable electrodes. Her team recently joined forces with Professor Ernst Meyer of the University of Basel whose research in experimental physics has revolved around scanning probe microscopy investigations of physical processes at surfaces


Graphene nanoribbons are strips of graphene with a width of no more than 50nm.
Graphene nanoribbons are strips of graphene with a width of no more than 50nm. Image used courtesy of the Department of Physics at the University of Basel, Switzerland.


Professor Meyer conducts investigations by establishing a formation of images through a physical probe that scans any specimen. Both teams were able to take a graphene material and dope it with nitrogen to create a robust, two-dimensional honeycomb lattice that presented semiconductor properties. 


The Study: Porous Nitrogen-Doped Graphene Strips 

Graphene is another element form of carbon. Uniquely exists with a single layer of carbon atoms arranged in a honeycomb structure. The material is of interest not only in basic research but also for various applications given to its properties, which include electrical conductivity as well as durability.

The combined team of Swedish chemists and physicists produced the first porous graphene ribbons in which specific carbon atoms in the crystal lattice are replaced with nitrogen atoms. These strips of graphene gave off semiconducting characteristics that could be used for a wide range of applications in electronics and quantum computing.

In order to synthesize the material’s voids, the researchers heated the individual building blocks up to 220°C, step by step on a silver surface in a vacuum space. Professor Meyer and his team were able to closely analyze this material through their scanning probe microscopy methods. Their observation showed that once more heat was applied to the graphene ribbons, the material pulled away from strictly being an electrical conductor to behaving as a semiconductor material. 


A New Kind of Ladder Structure

Colleagues from the Universities of Bern and Warwick were able to review and confirm the research findings by performing theoretical calculations of the electronic properties. Dr. Rémy Pawlak, author of the theoretical calculations gave his input on what made the graphene strips exemplify semiconductor material, “The semiconducting properties are essential for the potential applications in electronics, as their conductivity can be adjusted specifically.” 

“We expect these porous, nitrogen-doped graphene ribbons to display extraordinary magnetic properties. In the future, the ribbons could therefore be of interest for applications in quantum computing,” Meyer said.

Graphene is easy to obtain and can be made in any household following a simple elementary science experiment. Mixing dish soap and water in a blender with a small amount of graphite can yield graphene. This is quite assuring for manufacturers, it should not take much to obtain graphene at affordable costs and aiming to replicate the process established by this research team. 

Graphite can also be used for developing electronics since it has great conductivity properties, studies have proved it can be used to create electrical circuits on human skin. Graphene is promising for developing a new wave of electronic devices, including diodes, transistors, and integrated circuits. With more research to be completed there are endless possibilities that can erupt -creating efficient and precise sensors, faster and efficient electronics, flexible displays, efficient solar panels,anti-corrosion coatings and paints, faster DNA sequencing, drug delivery, and more.