Spontaneous emission enhancement of single-layer WSe₂ coupled to a microcavity

Atomically thin layers of transition metal dichalcogenides such as single-layer WSe₂ have recently attracted much attention as promising material candidates for optoelectronic applications. Engineering the spontaneous emission rate in these materials is expected to improve the performance and functionalities of optoelectronic devices. In this talk, we show the photoluminescence (PL) enhancement of mechanically exfoliated single-layer WSe₂ integrated to a microcavity. We directly contact silicon dioxide microspheres with diameters ranging from 2 to 7 μm on single-layer WSe₂ to control the enhancement rate. We found that the experimentally obtained Purcell factor agrees well with that calculated by the finite-difference time-domain (FDTD) simulation. The Purcell enhancement is further supported by the direct measurement of the radiative decay rate of WSe₂ with and without microspheres. Our finding provides a way to manipulate optical properties of single-layer semiconductors for optoelectronic applications and integrated nanophotonics.