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.

Single crystal diamond membranes for nanoelectronics.

Single crystal, nanoscale diamond membranes are highly sought after for a variety of applications including nanophotonics, nanoelectronics and quantum information science. However, so far, the availability of conductive diamond membranes has remained an unreachable goal. In this work we present a complete nanofabrication methodology for engineering high aspect ratio, electrically active single crystal diamond membranes. The membranes have large lateral directions, exceeding ∼500 × 500 µm2 and are only several hundreds of nanometers thick. We further realize vertical single crystal p-n junctions made from the diamond membranes that exhibit onset voltages of ∼10 V and a current of several mA. Moreover, we deterministically introduce optically active color centers into the membranes, and demonstrate for the first time a single crystal nanoscale diamond LED. The robust and scalable approach to engineer the electrically active single crystal diamond membranes offers new pathways for advanced nanophotonic, nanoelectronic and optomechanical devices employing diamond.

Enhanced photoluminescence from single nitrogen-vacancy defects in nanodiamonds coated with phenol-ionic complexes.

Fluorescent nanodiamonds are attracting major attention in the field of bio-sensing and bio-labeling. In this work we demonstrate a robust approach to achieve an encapsulation of individual nanodiamonds with phenol-ionic complexes that enhance the photoluminescence from single nitrogen vacancy (NV) centers. We show that single NV centres in the coated nanodiamonds also exhibit shorter lifetimes, opening another channel for high resolution sensing. We propose that the nanodiamond encapsulation reduces the non-radiative decay pathways of the NV color centers. Our results provide a versatile and assessable way to enhance photoluminescence from nanodiamond defects that can be used in a variety of sensing and imaging applications.