Formation of GeV, SiV, and NV Color Centers in Single Crystal Diamond Needles Grown by Chemical Vapor Deposition

Abstract

Herein the color centers formation in diamond crystallites of pyramidal shape grown by chemical vapor deposition (CVD) is described. The individual crystallites are extracted from polycrystalline films grown on silicon substrates. The silicon‐vacancy (SiV), germanium‐vacancy (GeV), and nitrogen‐vacancy (NV) centers are created by introducing corresponding precursors from substrate material, gaseous nitrogen, and thermally evaporated germanium added during CVD. Some amount of NV centers detected in all types of the diamond crystallites is assigned to uncontrollable presence of nitrogen in the CVD reactor. The low temperature photoluminescence spectra indicate presence of ensembles of SiV centers in diamond structure. The SiV centers are concentrated predominantly at apexes of the diamond crystallites located at substrate surface. Intense growth of CN radicals in plasma‐activated gas environment during CVD process is detected after nitrogen gas addition. The crystallites obtained with the nitrogen addition demonstrate significant variation of their pyramid angle. The photoluminescence spectra of crystallites grown with nitrogen addition demonstrate increase of both negatively and neutrally charged states of NV color center. The GeV centers are created via thermal evaporation of pure Ge during CVD growth. The photoluminescence spectra of the crystallites grown with Ge addition demonstrate presence of GeV color centers ensemble.

Single-Crystal Diamond Needle Fabrication Using Hot-Filament Chemical Vapor Deposition

“…As a rule, all these spectra contained Raman signals, as well as the intensive line located close to 738 nm. The position and shape of this line corresponded to the zero-phonon luminescence of the negatively charged SiV color center in diamond [ 15 ]. Similar to the case of the diamond needles obtained using DC-discharge plasma-enhanced CVD [ 15 ], the formation of the SiV centers may be explained by silicon substrate etching in an activated (ionized) hydrogen atmosphere and the subsequent introduction of gasified silicon precursors into the diamond lattice [ 29 ].…”

“…The position and shape of this line corresponded to the zero-phonon luminescence of the negatively charged SiV color center in diamond [ 15 ]. Similar to the case of the diamond needles obtained using DC-discharge plasma-enhanced CVD [ 15 ], the formation of the SiV centers may be explained by silicon substrate etching in an activated (ionized) hydrogen atmosphere and the subsequent introduction of gasified silicon precursors into the diamond lattice [ 29 ]. Additionally, silicon impurities in the diamond may have resulted from the chemical interaction of activated hydrogen with quartz (i.e., SiO 2 ) elements (substrate supporting plates) in the reactor chamber.…”

“…Additionally, silicon impurities in the diamond may have resulted from the chemical interaction of activated hydrogen with quartz (i.e., SiO 2 ) elements (substrate supporting plates) in the reactor chamber. Since HF CVD does not explicitly imply plasma or free-electron generation, the mentioned growth mechanisms, which were realized during the DC-discharge plasma-enhanced CVD of the needles [ 15 ], could not be directly applied to this case. However, some similar chemical processes might be involved related to this concern, as follows.…”

“…The crystallites produced by the combination of DC CVD and selective oxidation have perfect pyramidal shapes and a radius of curvature at their apex in the range of a few to a hundred nanometers. The effects of the DC CVD process parameters on the shape and properties of the needles were investigated [ 11 , 12 , 13 , 14 , 15 ], as well as the ability for the controllable creation of luminescent color centers, such as silicon-vacancy (SiV), nitrogen-vacancy (NV), and germanium-vacancy (GeV) color centers, during the single-step growth process. One of the limiting factors of the DC gas discharge-based technology is the necessity for conductive substrates for the film deposition.…”

Nanocarbon Photonics and Optoelectronics

“…The contributions (in total amount of 13) of this Special Section are presented by a Feature Article and twelve Original Papers devoted to the problem of electrostatic confinement of massless Dirac particles, non‐linear optical effects in non‐carbon nano‐structured matters such as topological insulator Bi 2 Se x and Ag/Pd nanocomposite films, particularities in field electron emission from micro‐tips decorated by nanoparticles, usage of graphene transfer technique for printing of micro‐ and nanoscale optical components on convex lenses, preparation and optical characterization of carbon nanotubes, different aspects related to graphene and graphenic materials formation, application of graphene materials for THz components, and creation of the color centers in diamond micro‐needle crystallites …”