Effect of boron doping on luminescent properties of silicon--vacancy and germanium--vacancy color centers in diamond particles obtained by chemical vapor deposition
At a Glance
Section titled “At a Glance”| Metadata | Details |
|---|---|
| Publication Date | 2022-01-01 |
| Journal | Физика твердого тела |
| Authors | S. A. Grudinkin, Н. А. Феоктистов, Kirill Bogdanov, А. В. Баранов, V. G. Golubev |
| Institutions | Ioffe Institute, ITMO University |
| Citations | 1 |
| Analysis | Full AI Review Included |
Technical Documentation & Analysis: Boron Doping Effects on Diamond Color Centers
Section titled “Technical Documentation & Analysis: Boron Doping Effects on Diamond Color Centers”Executive Summary
Section titled “Executive Summary”This research investigates the critical role of boron doping in controlling the photoluminescence (PL) properties of Silicon-Vacancy (SiV) and Germanium-Vacancy (GeV) color centers synthesized in diamond particles via Chemical Vapor Deposition (CVD).
- Core Achievement: Successful synthesis of Boron-Doped Diamond Particles (BDD DPs) containing SiV and GeV centers using Hot Filament CVD (HFCVD).
- Quantum Sensing Indicator: The intensity of the SiV Zero Phonon Line (ZPL) at 738.2 nm exhibits a strong, sensitive dependence on low boron concentrations (0-46 ppm B/C gas ratio).
- Doping Quantification: SiV ZPL quenching is confirmed as a reliable indicator for detecting the embedding of boron atoms into the diamond lattice at low doping levels, crucial for quantum material engineering.
- High Doping Effects: High boron doping (64000 ppm B/C gas) induces a Fano resonance in the Raman spectra, characterized by a shift of the diamond band from 1332 cm-1 to 1322 cm-1, confirming high substitutional boron concentration (~ 1.1 · 1021 cm-3).
- Application Relevance: The ability to tune the charge state and luminescence intensity via boron doping is essential for developing single-photon sources, quantum sensors (e.g., optical temperature sensors), and advanced biomedical markers (e.g., local hyperthermia agents).
Technical Specifications
Section titled “Technical Specifications”| Parameter | Value | Unit | Context |
|---|---|---|---|
| Synthesis Method | HFCVD | N/A | Hot Filament Chemical Vapor Deposition |
| Tungsten Coil Temperature | 2000 - 2200 | °C | HFCVD process parameter |
| Operating Pressure | 48 | Torr | HFCVD process parameter |
| Methane Concentration | 4 | % | Carbon source |
| Boron/Carbon Ratio ((B/C)gas) Range | 14 to 64000 | ppm | Diborane (B2H6) doping range |
| SiV ZPL Wavelength | 738.2 | nm | Silicon-Vacancy color center (negative charge state) |
| GeV ZPL Wavelength | 602.3 | nm | Germanium-Vacancy color center (negative charge state) |
| Diamond Raman Shift (Undoped) | ~ 1332 | cm-1 | F2g optical phonon symmetry mode |
| Diamond Raman Shift (High B Doping) | ~ 1322 | cm-1 | Shift due to Fano resonance at 64000 ppm (B/C)gas |
| Estimated Lattice B Concentration (High Doping) | ~ 1.1 · 1021 | cm-3 | Calculated from Fano resonance fitting |
| SiV ZPL Quenching Range | 0 to 46 | ppm | Strongest decrease in ZPL intensity |
| Surface Roughness (DPs) | 0.9 to 1.5 | µm | Size range of synthesized diamond particles (AFM) |
Key Methodologies
Section titled “Key Methodologies”The experiment focused on synthesizing and characterizing boron-doped diamond particles (DPs) containing SiV and GeV centers.
- Synthesis Technique: Boron-doped DPs were synthesized using Hot Filament Chemical Vapor Deposition (HFCVD), chosen specifically for its enhanced efficiency in boron injection compared to Microwave Plasma CVD (MPCVD).
- Gas Mixture & Doping: The process utilized 4% Methane and 480 sccm Hydrogen at 48 Torr. Boron doping was achieved by introducing Diborane (B2H6), controlling the B/C ratio in the gas phase from 14 ppm up to 64000 ppm.
- Color Center Precursors: Silicon (SiV source) was introduced via the crystalline silicon substrate, and Germanium (GeV source) was introduced via a crystalline germanium plate placed adjacent to the substrate holder. Atomic hydrogen etching of these solid sources provided volatile radicals (SiHx, GeHx) for incorporation.
- Characterization: Photoluminescence (PL) and Raman Scattering (RS) spectra were measured at room temperature using a Renishaw InVia micro-Raman spectrometer in backscatter geometry (488 nm excitation).
- Data Modeling: The RS spectra of highly doped particles were analyzed using the Fano resonance model (Fano function) to decompose individual RS bands and estimate the concentration of substitutional boron atoms.
6CCVD Solutions & Capabilities
Section titled “6CCVD Solutions & Capabilities”6CCVD specializes in high-quality MPCVD diamond, offering superior purity, uniformity, and scalability compared to the HFCVD method used in this research. We provide the foundational materials and customization necessary to replicate and advance this work from particle-based studies to integrated, wafer-scale devices for quantum and electrochemical applications.
| Research Requirement | 6CCVD Material Solution | Customization Potential & Advantage |
|---|---|---|
| Controllable Boron Doping | Heavy Boron Doped PCD/SCD (BDD): We offer precise, controllable BDD across the full range (from trace doping for charge control up to metallic conductivity > 1020 cm-3). | Our MPCVD process ensures superior doping uniformity across large wafers (up to 125mm PCD), critical for scalable device fabrication (e.g., transparent conductive electrodes). |
| High-Quality Color Center Host | Optical Grade Single Crystal Diamond (SCD): Required for high-coherence quantum applications (SiV, GeV, NV). Our SCD is grown with ultra-low defect density. | Available in thicknesses from 0.1 µm to 500 µm, allowing researchers to optimize the active layer depth for specific color center implantation or in-situ growth. |
| Custom Precursor Integration | Custom CVD Recipes: 6CCVD can assist in developing CVD recipes for in-situ incorporation of Si, Ge, or other precursors (Sn, Ni) into SCD or PCD films, ensuring the formation of desired color centers. | We provide substrates and films with Ra < 1nm (SCD) and Ra < 5nm (PCD), minimizing surface defects that can quench ZPL intensity. |
| Device Integration & Electrodes | Custom Metalization & Polishing: The research highlights BDD’s use in electrochemical and hyperthermia applications, requiring conductive contacts. | We offer in-house metalization services (Au, Pt, Pd, Ti, W, Cu) and laser cutting to produce custom dimensions and electrode patterns, ready for integration. |
Engineering Support
Section titled “Engineering Support”6CCVD’s in-house PhD team provides expert consultation for projects requiring precise control over diamond properties, including:
- Material Selection: Advising on the optimal diamond grade (SCD vs. PCD) and doping level (BDD) to achieve specific charge states and luminescence properties for Quantum Sensing and Biomedical Marker projects.
- Scalability: Transitioning successful particle-based research to high-quality, large-area SCD or PCD wafers (up to 125mm) for commercial device prototyping.
- Surface Preparation: Ensuring ultra-low roughness (Ra < 1nm) and specific surface terminations necessary for maximizing spin coherence times and minimizing spectral diffusion in color centers.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
The effect of doping with boron on the luminescent properties of diamond particles synthesized by Hot Filament Chemical Vapor Deposition technique with color centers embedded during the growth process has been studied. It is shown that at low boron doping level, the photoluminescence intensity of a narrow zero-phonon line of the silicon-vacancy color center (738.2 nm) demonstrates a strong dependence on the concentration of boron atoms at the sites of the diamond lattice. The dependence of the intensity of a broad photoluminescence band in the wavelength range 520-800 nm on the concentration of boron atoms in the gas mixture in the range from 14 to 64000 ppm has been analyzed. The Raman scattering spectra of the obtained particles have been studied. At the concentration of boron atoms in the gas mixture up to 1540 ppm, the Raman scattering spectra of diamond particles practically do not change when the boron concentration is varied. At high boron doping level, the diamond band in the Raman spectra exhibit a spectral response typical of the Fano resonance. Keywords: diamond particles, color centers, boron doping, photoluminescence, chemical vapor deposition.