Quantum emission from localized defects in zinc sulfide

Single-photon sources in solid-state systems are widely explored as fundamental constituents of numerous quantum-based technologies. We report the observation of single-photon emitters in zinc sulfide and present their photophysical properties via established spectroscopy techniques. The emitter behaves like a three-level system with an intermediate metastable state. It emits at ∼640 nm, and its emission is linearly polarized, with a lifetime of (2.2±0.8) ns. The existence of single-photon sources in zinc sulfide is appealing due to the well-established manufacturing techniques of the material, its versatile technological uses, as well as the availability of many zinc isotopes with potential for designing ad hoc emitter-host pairs with tailored properties.