Ag–Diamond Core–Shell Nanostructures Incorporated with Silicon-Vacancy Centers

Abstract

Silicon-vacancy (SiV) centers in diamond have attracted attention as highly stable fluorophores for sensing and as possible candidates for quantum information science. While prior studies have shown that the formation of hybrid diamond–metal structures can increase the rates of optical absorption and emission, many practical applications require diamond plasmonic structures that are stable in harsh chemical and thermal environments. Here, we demonstrate that Ag nanospheres, produced both in quasi-random arrays by thermal dewetting and in ordered arrays using electron-beam lithography, can be completely encapsulated with a thin diamond coating containing SiV centers, leading to hybrid core–shell nanostructures exhibiting extraordinary chemical and thermal stability as well as enhanced optical properties. Diamond shells with a thickness on the order of 20–100 nm are sufficient to encapsulate and protect the Ag nanostructures with different sizes ranging from 20 nm to hundreds of nanometers, allowing them to withstand heating to temperatures of 1000 °C and immersion in harsh boiling acid for 24 h. Ultrafast photoluminescence lifetime and super-resolution optical imaging experiments were used to study the SiV properties on and off the core–shell structures, which show that the SiV on core–shell structures have higher brightness and faster decay rate. The stability and optical properties of the hybrid Ag–diamond core–shell structures make them attractive candidates for high-efficiency imaging and quantum-based sensing applications.

Inward motion of diamond nanoparticles inside an iron crystal

“…13). In terms of the broader applicability of our transport mode, metallic or ceramic nanoparticles other than DNPs can be deposition-coated with a diamond shell with a tunable thickness 36,37 , such that they can also be introduced into Fe or steels. The translational transport of nanoscale particulate matter opens an easier way for creating gradient composites with enhanced nearsurface properties.…”

Enhancing Diamond Color Center Fluorescence via Optimized Configurations of Plasmonic Core–Shell Nanoresonator Dimers

“…Most of the previous studies have focused either on the excitation or emission enhancement alternatively, and only a few works were presented on simultaneously enhanced phenomena. − In this study, we show numerically optimized ellipsoidal core–shell dimers, designed to simultaneously enhance the excitation and emission of SiV and NV color centers. Although the fabrication of the proposed silica-metal ellipsoidal core–shell dimer and color-center-implanted diamond slab assembly is experimentally challenging, there are recent experiments where silver nanoparticles embedded into diamond were created with high tunability and scalability by combining chemical vapor deposition, evaporation, and heating . In another structure, color centers were created by ion implantation with an accuracy of 5 nm .…”

“…Although the fabrication of the proposed silica-metal ellipsoidal core–shell dimer and color-center-implanted diamond slab assembly is experimentally challenging, there are recent experiments where silver nanoparticles embedded into diamond were created with high tunability and scalability by combining chemical vapor deposition, evaporation, and heating. 30 In another structure, color centers were created by ion implantation with an accuracy of 5 nm. 31 As a bottom-up approach, atomic force microscopy was used to assemble elongated core–shell nanoparticles 23 , 32 into dimers with a high accuracy.…”

Plasmonically Enhanced Superradiance of Broken-Symmetry Diamond Color Center Arrays Inside Core-Shell Nanoresonators

“…The plasmonic enhancement of spontaneous emission was demonstrated for NV and SiV diamond color centers as well [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ]. The previously used plasmonic nanoresonators include convex nano-objects, e.g., singlets and doublets of nanospheres [ 18 , 19 ], nanorods [ 20 , 21 ], nanowires [ 22 , 23 , 24 ], patch-antennas [ 25 ] and concave core-shell nanoparticles [ 26 ], as well as periodic arrays of convex nanospheres and concave plasmonic nanoapertures [ 19 , 27 , 28 ].…”

“…The plasmonic enhancement of spontaneous emission was demonstrated for NV and SiV diamond color centers as well [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ]. The previously used plasmonic nanoresonators include convex nano-objects, e.g., singlets and doublets of nanospheres [ 18 , 19 ], nanorods [ 20 , 21 ], nanowires [ 22 , 23 , 24 ], patch-antennas [ 25 ] and concave core-shell nanoparticles [ 26 ], as well as periodic arrays of convex nanospheres and concave plasmonic nanoapertures [ 19 , 27 , 28 ]. Further emission improvement is possible by exploiting cooperative phenomena, e.g., superradiance (SR) that makes it possible to develop extremely fast photonic circuit elements smaller than the resonant wavelength, which is crucial in many quantum information processing applications.…”