Microcavity enhanced single photon emission from two-dimensional WSe2

Atomically flat semiconducting materials such as monolayer WSe_2 hold great promise for novel optoelectronic devices. Recently, quantum light emission has been observed from bound excitons in exfoliated WSe_2. As part of developing optoelectronic devices, the control of the radiative properties of such emitters is an important step. Here we report the coupling of a bound exciton in WSe_2 to open microcavities. We use a range of radii of curvature in the plano-concave cavity geometry with mode volumes in the λ^3 regime, giving Purcell factors of up to 8 while increasing the photon flux five-fold. Additionally we determine the quantum efficiency of the single photon emitter to be η = 0.46 ± 0.03. Our findings pave the way to cavity-enhanced monolayer based single photon sources for a wide range of applications in nanophotonics and quantum information technologies.