Effect of thermal annealing on photoluminescence in single layer MoS₂ on Au

We have used exciton and trion emission energies as a sensitive probe to investigate the interaction between single-layer (1L) MoS₂ and Au, a technologically relevant interface for future device technologies. Our results suggest that grain sizes of evaporated Au can affect these energies and that thermal annealing introduces non-trivial and non-monotonic perturbation to charge transfer. The discussions presented in this paper indicates that further work to determine spatial dependencies of these energies using micro-photoluminescence spectroscopy will be able to delineate the interaction more clearly between 1L MoS₂ and Au.