Electronic tailoring of graphene nanostructures via on-surface synthesis

Eduard Carbonell, Pre-doctoral Researcher at the nanoimaging Group at CIC nanoGUNE, received his PhD at the University of the Basque Country (UPV/EHU) after the defense of his thesis project on 28 July 2017. His research work, entitled “Electronic tailoring of graphene nanostructures via on-surface synthesis", has been developed under the supervision of Dr. José Ignacio Pascual, nanoimaging group leader.

An international committee including leading researchers in the field was selected to assess the research project:

The defense consisted of a presentation by the candidate on the main aspects of the Ph.D. thesis project followed by an extended discussion based upon the questions that each one of the members of the committee raised in relation to the research work that has been carried out by Eduard Carbonell during his PhD studies. After its final deliberation, the committee decided to award the candidate the Doctor Degree with the highest mention existing at UPV/EHU (cum laude). 

After the defense, we asked Dr. Eduard Carbonell to explain us a bit more about his project:

Which was the subject of your thesis?

My thesis focused on the growth of graphene nanoribbons and, in particular, the study of their electronic properties. When built without deffects and at small enough widths (smaller than 10nm), graphene nanoribbons can behave as semiconductors while preserving most of the outstanding properties of graphene.

Why did you choose this subject?

Graphene has a great potential in electronic applications though we still need to overcome some limitations to achieve a widespread use of this material. This project allowed me to study graphene down to the atomic scale, while trying to overcome the limitation that graphene poses in semiconductor applications, its lack of a bandgap.

Which metodology/techniques did you use?

The main tool I used was a Low Temperature (4K) Scanning Tunneling Microscope at Ultra High Vacuum conditions. This technique allowed us to study the structure of the nanoribbons with atomic resolution and their electronic properties, such as the bandgap and the electronic band structure.

Which have been the main conclusions?

Our studies have shown that we can build graphene nanoribbons with widhts lower than 1 nm while integrating other atoms or chemical species, such as boron or cyano groups, in their structure. These precise atomic changes have allowed us to tune not only the bandgap of the graphene nanoribbons but also to dope these structures and pave the way to potential graphene nanodevices.

What could be the contribution of your research for present or future nanotechnologies?

Although graphene nanoribbons are still far from being used on real-world applications, our studies can help understand how to tune graphene and its nanostructures to create graphene based nanodevices in the future.

How do you feel now that you have finished the thesis? Which are your plans for the future?

I am very happy about my thesis experience, it has taught me a lot both from a professional and personal perspective, like dealing with frustration and overcoming unique challenges by yourself. It has certainly been an exciting trip. My future plans are to join the R&D department of a laser company