Besides graphene, there is a whole class of new two-dimensional materials with interesting optical and electronic properties. Among them are metal-chalcogenides, which show beneficial properties for applications as optoelectronic materials such as active films for PV devices: they exhibit high absorption coefficient, band gap tunable by composition, and efficient carrier multiplication. In general, these materials feature atomic layers that are only weakly bonded by van der Waals interactions. Similar to graphite in the case of graphene, those can be readily split into single nanosheets by mechanical or liquid exfoliation processes.
In this project, we make metal-chalcogenide nanosheets by mechanical exfoliation, and study their optical and excitonic properties by Raman spectroscopy, photoluminescence and reflectivity measurements.