| AVS 64th International Symposium & Exhibition | |
| 2D Materials Focus Topic | Tuesday Sessions |
| Session 2D-TuA |
| Session: | Growth of 2D Materials |
| Presenter: | Piotr Ciochoń, Institute of Physics, Jagiellonian University, Poland |
| Authors: | P.K. Ciochoń, Institute of Physics, Jagiellonian University, Poland J.J. Kołodziej, Institute of Physics, Jagiellonian University, Poland |
| Correspondent: | Click to Email |
A new approach to the synthesis of high-quality graphene on silicon carbide
One of the most widely used methods of graphene synthesis is the graphitization of the (0001) and (000-1) surfaces of silicon carbide crystal. In order to obtain high quality graphene, it is necessary to slow down the excessive sublimation of silicon, observed at temperatures at which graphene ordering occurs. The most widely used method to accomplish this is carrying out the graphitization process in the presence of atmospheric pressure of inert buffer gases, such as argon.
We propose an alternative approach to solve this issue, which relies on exposing SiC surface during thermal annealing to the high-purity beam of silicon, obtained from an external sublimation source. The proposed solution has two advantages over the buffer-gas method. Firstly, it reduces the amount of impurities present near the surface by several orders of magnitude, as compared to even the purest inert gases at the atmospheric pressure. Secondly, it allows for precise control over the process parameters, leading to the possibility of near-equilibrium graphitization.
We have performed a thorough study of the process, systematically varying the parameters, such as graphitization temperature, process time and the silicon flux density and found that the synthesized graphene is characterized by very high degree of crystallographic ordering, low concentration of defects and large size of monocrystalline domains. Varying the process parameters, we were have been able to control the number of synthesized graphene layers, without the deterioration of overall graphene quality. Moreover, the process has shown a remarkable reproducibility, allowing for proper standardization of the synthesized material, a step considered crucial for the widespread introduction and use of graphene-based devices.
Our method allows for fast, reproducible synthesis of a very high-quality graphene directly on an insulating surface and is perfectly suited for preparing hybrid heterostructures and intercalation of foreign atoms. We have performed preliminary studies of intercalation with Cr atoms, during the graphitization process, as our approach allows to overcome several problems, resulting in unsuccessful past attempts.