  Synthesis and characterization of high-quality single-crystal WSe2 films on
highly-insulating substrate is presented. We demonstrate for the first time
that the presence of gold nanoparticles in the basal plane of a WSe2 film can
enhance its Raman scattering intensity. The experimentally observed enhancement
ratio in the Raman signal correlates well with the simulated electric field
intensity using a three-dimensional electromagnetic software and theoretical
calculation. This work provides guidelines for the use of two-dimensional WSe2
films as a SERS substrate.
