Regensburg 2025 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

O: Fachverband Oberflächenphysik

O 33: Poster Graphene: Electronic Structure and Excitations

O 33.15: Poster

Tuesday, March 18, 2025, 13:30–15:30, P3

Free-standing graphene films/membranes — •Leon Lasnig, Lukas Kalkhoff, Steffen Franzka, and Marika Schleberger — Faculty of Physics and CENIDE, University of Duisburg-Essen, Duisburg, Germany

Large-area graphene films are usually grown onto a copper sheet via chemical vapor deposition. The transfer of the graphene to another substrate to this date has been done with the help of polymer films, which leads to impurities and residues. These residues can change the properties of graphene. It is therefore necessary to develop new fabrication protocols to prevent or at least minimize contaminations.
Here we present a new technique for fabricating membranes without the requirement of an PMMA layer. The samples were then transferred on hole substrates with a hole diameter of 150 µm. Since a monolayer is not stable enough to cover the hole, samples with multiple layers were prepared. These were characterized using Raman spectroscopy and an optical profilometer. Raman spectroscopy showed that the samples within the holes are very homogeneous in terms of doping and strain. The lack of D mode in the measured Raman spectra indicates a clean sample. The profilometer revealed that the graphene membranes in the holes have an average hight deviation of only 138 nm.

Keywords: Suspended graphene; Raman spectroscopy; Optical profilometer