Color centers in diamond are being studied as potential single-photon sources for quantum devices. As a single-photon source, the silicon-vacancy (SiV) color center has demonstrated the most promise among them. Even at room temperature and at higher temperatures, it shows strong emission in the zero-phonon line (ZPL) [1].
Single-color centers in thin polycrystalline diamond membranes allow the platform to be used in integrated quantum photonics, hybrid quantum systems, and other complex functional materials. While single-crystal diamond membranes are still technologically challenging to fabricate as they cannot be grown on a non-diamond substrate, free-standing polycrystalline diamond membranes can be conveniently fabricated at large-scale from nanocrystalline diamond seeds on a substrate that can be selectively etched. However, their practical application for quantum photonics is so far limited by crystallographic defects, impurities, graphitic grain boundaries, small grain sizes, scattering loss, and strain. In this paper, we report on a single-photon source based on silicon-vacancy color centers in a polycrystalline diamond membrane. We discuss the spectroscopic approach and quantify the photon statistics, obtaining a g2(0) ≈ 0.04. Our findings hold promise for introducing polycrystalline diamond to quantum photonics and hybrid quantum systems.
Silicon-vacancy (SiV) centers in diamond are gaining an increased interest for application, such as in quantum technologies and sensing. Due to the strong luminescence concentrated in its sharp zero-phonon line at room temperature, SiV centers are being investigated as single-photon sources for quantum communication, and also as temperature probes for sensing. Here, we discussed strategies for the fabrication of SiV centers in diamond based on Si-ion implantation followed by thermal activation. SiV color centers in high-quality single crystals have the best optical properties, but polycrystalline micro and nanostructures are interesting for applications in nano-optics. Moreover, we discuss the photoluminescence properties of SiV centers in phosphorous-doped diamond, which are relevant for the creation of electroluminescent devices, and nanophotonics strategies to improve the emission characteristics of the SiV centers. Finally, the optical properties of such centers at room and high temperatures show the robustness of the center and give perspectives for temperature-sensing applications.
The silicon vacancy (SiV) color centers in diamond have significant potential in the fields of quantum information, nanophotonics, bioimaging and sensing, due to its good structural stability at room temperature, strong photostability, short luminescence lifetime, narrow zero-phonon line bandwidth, and avoidance of biological autofluorescence. They have attracted extensive attention and in-depth research from researchers. The applications of SiV color centers in the above areas require addressing key issues such as control over the number and charge state of SiV color centers in diamond, as well as improving the luminous efficiency. Therefore, this review summarizes some recent relevant research progress, including common methods for preparing SiV color centers, control over their luminescence intensity, preparation of SiV single-photon sources, and research on the control of SiV color center charge states. Based on these, an outlook is provided for the preparation and application of SiV color centers in diamond.
Optical sources that deliver single photons on demand play a key role in quantum cryptography and optical quantum computations. At present, color centers in wide-bandgap semiconductors, such as the nitrogen-vacancy (NV) and silicon-vacancy (SiV) centers in diamond, are considered to be the most promising candidates for practical quantum information applications owing to their unique emission properties at room temperature. However, for practical reasons, single-photon sources should be pumped electrically, which is required for integrability, scalability, and energy efficiency. However, diamond and related wide-bandgap semiconductor materials are at the interface between insulators and semiconductors, which makes electrical excitation of color centers very challenging. Here, we report on our progress in the understanding of single-photon electroluminescence of color centers in diamond, discuss different factors affecting the brightness of these emitter under electrical excitation, and study how to improve the performance of electrically- pumped single-photon sources based on color centers in diamond.
Quantum photonics platforms hold considerable potential for the rapid development and deployment of quantum information and computing technologies. Color centers in diamond, such as silicon-vacancy (SiV) centers, have numerous attractive properties for such applications, including high brightness, narrow zero-phonon line (ZPL) linewidths at 737nm, and stable single-photon emission insusceptible to electric field fluctuations [1]. Color centers in photonic diamond nanostructures have been demonstrated recently [2], but their fabrication is challenging and requires sophisticated techniques and equipment.
Single silicon vacancy (SiV) color centers in diamond have recently shown the ability for high brightness, narrow bandwidth, room temperature single photon emission. This work develops a model describing the three level population dynamics of single SiV centers in diamond nanocrystals on iridium surfaces including an intensity dependent de-shelving process. Furthermore, we investigate the brightness and photostability of single centers and find maximum single photon rates of 6.2 Mcps under continuous excitation. We investigate the collection efficiency of the fluorescence and estimate quantum efficiencies of the SiV centers.