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: