Engineering the Radiative Lifetime of Excitons in Two-dimensional van der Waals Heterostructures

We investigate the suppression of exciton spontaneous emission in two-dimensional van der Waals heterostructures integrated with photonic resonant structures. In this work, we focus on photonic resonators composed of parallel-plate dielectric waveguides. We show that modification of the local density of optical states of photonic resonators leads to an increase of the radiative lifetime of excitons in van der Waals monolayers integrated into dielectric waveguides. We show that the lifetime increase requires placing the monolayer in the local minima of the waveguide mode electric field. We demonstrate that the maximum radiative lifetime is limited by the radiative losses of leaky photonic modes.