  Two-dimensional chalcogenide semiconductors have recently emerged as a host
material for quantum emitters of single photons. While several reports on
defect and strain-induced single photon emission from 2D chalcogenides exist, a
bottom-up, lithography-free approach to producing a high density of emitters
remains elusive. Further, the physical properties of quantum emission in the
case of strained 2D semiconductors are far from being understood. Here, we
demonstrate a bottom-up, scalable, and lithography-free approach to creating
large areas of localized emitters with high density (~150 emitters/um2) in a
WSe2 monolayer. We induce strain inside the WSe2 monolayer with high spatial
density by conformally placing the WSe2 monolayer over a uniform array of Pt
nanoparticles with a size of 10 nm. Cryogenic, time-resolved, and gate-tunable
luminescence measurements combined with near-field luminescence spectroscopy
suggest the formation of localized states in strained regions that emit single
photons with a high spatial density. Our approach of using a metal nanoparticle
array to generate a high density of strained quantum emitters opens a new path
towards scalable, tunable, and versatile quantum light sources.
