High-Resolution TEM on Graphene

Jens Kling
Project coordinators: Thomas W. Hansen (CNG) and Jakob B. Wagner (GRAFOL)

Graphene, as the forefather of 2D-materials, attracts much attention due to its extraordinary properties like transparency, flexibility and outstanding high conductivity, together with a thickness of only one atom. The properties seem to be dependent on the atomic structure of graphene and therefore characterizations on the atomic level are of interest. High-resolution transmission electron microscopy (HRTEM) is a state-of-the-art method to characterize the atomic structure of materials. Due to the inherently low mass-thickness of graphene and the limited stability under an electron beam, the imaging and interpretation of the interpretation of the recorded images are challenging.

We are not only interested in imaging the perfect graphene structure. As part of the “Center for Nanostructured Graphene” (CNG) at DTU, we are especially interested in modified graphene. As the pattering of graphene influences the macroscopic properties, the question is how it is related to the atomic structure. How does the edge termination of the induced holes look and can this be related to changes in characteristics?

Chemical vapor deposition (CVD) is the growth method for large-scale graphene. The European project “GRAFOL” aims for a roll-based CVD machine for the mass production of few-layer graphene. The growth process on a substrate is in principle possible to follow in situ using an Environmental TEM. This is a big challenge, as a suitable substrate geometry is necessary and the introduced gas like methane limits the resolution. By following the growth process, we hope to understand it in more detail and can give input to optimize growth parameters in CVD.

                     

Further information about the projects can be found under:

CNG:              www.cng.dtu.dk
GRAFOL:       www.grafol.eu

Jens Kling
Academic Laboratory Technician
DTU Cen
+45 45 25 64 70
Thomas Willum Hansen
Senior Researcher
DTU Cen
+45 45 25 64 76
Jakob Birkedal Wagner
Professor, Scientific director
DTU Cen
+45 45 25 64 71