Excitons in 1D and 2D semiconductors

Excitons in van der Waals semiconductors interact strongly with light and have been the subject of intense investigation for future optoelectronic applications. In this presentation, I will report our recent studies on excitons in MoSe2 and WSe2 heterostructures, including measurements on the spatial coherence of interlayer excitons, and the localization of excitons using lithographically defined graphene gates. I will also discuss our recent studies on a one-dimensional van der Waals semiconductor SbPS4. SbPS4 can be exfoliated using the scotch tape method to yield long (several micron) nanobundles with typical thicknesses of 1-100 nm. The nanobundles emit ultra-broadband and bright photoluminescence when excited with 400 nm light.