ANALYSIS OF HYDROGENATED GRAPHENE BY CLASSICAL AND TIP ENHANCED RAMAN SPECTROMETRY

Work package:
Hydrogenation or fluorination of well-defined regions of monolayer graphene on a SiO2 substrate is of great interest for nanoelectronics because it makes it possible to open an energy gap in the electronic band structure of graphene and, in the case of hydrogenation, to have spin-polarised bands. However, competition between hydrogenation, etching, and the Eley-Rideal process (extraction of hydrogen from a surface by hydrogen radical) means that the hydrogenation window is narrow, which explains the lack of applications reported in the literature. Over the last few years, CEMES and LPCNO have been working closely together on this topic, to obtain hydrogenation or fluorination conditions for monolayer graphene and produce new devices based on hydrogenated or fluorinated graphene. This internship will cover the fabrication of samples (hydrogenation, nanofabrication of devices, which may include travel abroad to the Dominican Republic or Denmark), followed by structural characterization, mainly by classical and tip-enhanced Raman spectroscopy, which may be compared to electrical characterization at low temperatures and under magnetic fields. Some samples are already available. Finally, the internship will model the results obtained. In addition to the permanent staff, the trainee will be helped by a PhD student in the various aspects of the internship: nanofabrication in a clean room at CEMES and at the Exfolab at the LPCNO, Raman spectroscopy at CEMES and electrical characterization at the LPCNO, which will enable him/her to discover the entire research chain. The modeling part will focus on calculating the graphene vibration frequencies (simple ab- initio modeling) needed to interpret the Raman spectra and adapting models to understand the evolution of Raman peak intensities as a function of the hydrogenation doses used. These data will then be compared with transport measurements. This internship is part of the GLADIATOR ANR program and Newca IRP-CNRS which are funding the technical environment.