Spectral and spatial isolation of single tungsten diselenide quantum emitters using hexagonal boron nitride wrinkles

Abstract

Monolayer WSe2 hosts bright single-photon emitters. Because of its compliance, monolayer WSe2 conforms to patterned substrates without breaking, thus creating the potential for large local strain, which is one activation mechanism of its intrinsic quantum emitters. Here, we report an approach to creating spatially isolated quantum emitters from WSe2 monolayers that display clean spectra with little detrimental background signal. We show that a bilayer of hexagonal boron nitride and WSe2 placed on a nanostructured substrate can be used to create and shape wrinkles that communicate local strain to WSe2, thus creating quantum emitters that are isolated from substrate features. We compare quantum emitters created directly on top of substrate features with quantum emitters formed along wrinkles and find that the spectra of the latter consist of mainly a single peak and a low background fluorescence. We also discuss possible approaches to controlling the emitter position along hexagonal boron nitride wrinkles.