  The discovery of two-dimensional transition metal dichalcogenides (2D TMDs)
has promised next-generation photonics and optoelectronics applications,
particularly in the realm of nanophotonics. Arguably, the most crucial
fundamental processes in these applications are the exciton migration and
charge transfer in 2D TMDs. However, exciton dynamics in 2D TMDs have never
been studied on a nanophotonic platform and more importantly, the control of
exciton dynamics by means of nanophotonic structures has yet to be explored.
Here, for the first time, we demonstrate the control of exciton dynamics in
MoS2 monolayers by introducing a hyperbolic metamaterial (HMM) substrate. We
reveal the migration mechanisms of various excitons in MoS2 monolayers.
Furthermore, we demonstrate the F\"orster radius of the A-excitons can be
increased by introducing HMMs through the nonlocal effects of HMMs due to the
Purcell effect. On the other hand, the diffusion coefficient is unchanged for
the C-excitons on HMMs. This study provides a revolutionary step forward in
enabling 2D TMD nanophotonics hybrid devices.

Materials Science;Mesoscale and Nanoscale Physics