Opto-electronic characterization of strain effects in graphene nanoribbons
We are looking for highly motivated students with a strong background in nanoscience, physics, or material science. We provide state-of-the-art facilities in a cutting-edge research field. For more information, please contact Dr. Mickael Perrin (Mickael.Perrin@empa.ch). For applications, please send a short motivation (including educa-tional background and exam grades).
Graphene nanoribbons (GNRs) are nanometers-sized have attracted a strong interest from researchers worldwide as they constitute an emerging class of quantum materials. They exhibit novel physical properties beyond graphene such as a largely tuneable bandgap, optical, magnetic and topological effects, all tailorable by their edge structure. Recently, GNRs have been integrated into field-effect transistor devices, exhibiting high on/off rati-os and quantum dot behavior at cryogenic temperatures. Theoretically, applying strain on GNRs has been been predicted to results in largely tunable bandgaps, as well as the ap-pearance of localized edgestate.
The aim of this project is to investigate strain effects in GNRs both electrically and using Raman spectroscopy. The GNRs will be transferred onto a flexible substrate that will be bend using a mechanically controllable break junction setup. This home-designed setup is installed in a cryostat for the investigation of temperature-dependent charge transport measurements. In addition, Raman spectroscopy will be used to identify the various vibra-tional modes present in GNRs and track their energy upon straining. The GNRs will be provided by the group of Prof. Roman Fasel at Empa. The student will learn:
- Sample fabrication in cleanroom environment
- Charge-transport measurements
- Raman spectroscopy
- Physics of GNR-based quantum devices