Developing novel methodologies for the nano-optical characterization of 2D materials

Traditional optical spectroscopies are unparalleled analytical tools in science. However, a fundamental physical barrier known as the diffraction limit prevents them from accessing length scales beneath 200 nanometres. This is especially problematic for the family of 2D materials, such as graphene and the transition metal dichalcogenides (TMDs), which hold promise for cheap, next-generation LEDs, photovoltaic cells and photodetectors, amongst many other applications. For 2D materials, properties are dictated at the nanoscale, making it critical to have optical tools beyond the diffraction limit. Tip-Enhanced Near-Field Optical Microscopy (TENOM) can provide the necessary resolution to analyse 2D materials, amongst a great many other systems. However, TENOM is notoriously difficult and hence is only practiced by a select number of research groups worldwide. The aim of this project is to develop new, highly reproducible methods for TENOM using metal nanowires and, thereafter, use TENOM to analyse standard and functionalised 2D materials. This will help to understand how order and disorder at the nanoscale can dictate properties at the macroscale. This knowledge shall then be validated through the production of primitive devices for applications. To summarise, this project hopes to overcome the problems of TENOM and then, using 2D materials as an example, show it has a unique ability to bring the analytical power of light to the nanometre scale.