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Research and Application Progress of Boron-doped Diamond Films

MetadataDetails
Publication Date2023-07-12
JournalHighlights in Science Engineering and Technology
AuthorsGuangqiang Hou, Jingyan Ye, Jiaxing Han, Zhenghang Han, Xiang Yu
InstitutionsChina University of Geosciences (Beijing)
Citations4
AnalysisFull AI Review Included

Technical Documentation & Analysis: Boron-Doped Diamond Films

Section titled “Technical Documentation & Analysis: Boron-Doped Diamond Films”

This document analyzes the research progress of Boron-Doped Diamond (BDD) films, focusing on preparation methods and electrochemical applications, and aligns the material requirements with the advanced manufacturing capabilities of 6CCVD.


The research confirms that Boron-Doped Diamond (BDD) is a critical material for expanding diamond applications beyond insulation into high-performance electrochemistry, sensing, and water treatment.

  • Material Transformation: BDD doping successfully converts diamond from an extreme insulator (up to 1012 Ω·m) into a highly conductive material, suitable for use as a conductor, semiconductor, or superconductor.
  • Synthesis Standard: Microwave Plasma Chemical Vapor Deposition (MW-PCVD) is identified as the superior method for producing high-quality BDD films, offering high plasma density and uniform deposition, despite high equipment cost and low deposition rates in typical lab settings.
  • Electrochemical Superiority: BDD electrodes exhibit exceptional performance characterized by a wide solvent potential window, very high oxygen precipitation potential, low background current, and superior chemical stability compared to traditional metal electrodes.
  • Key Applications: BDD membranes are essential anode materials for advanced electrochemical wastewater treatment (generating free radicals for pollutant decomposition) and highly sensitive detection of trace organic compounds (e.g., amino acids, DNA/RNA).
  • Critical Requirement: Achieving optimal electrochemical performance requires precise control over boron doping concentration and high film quality, necessitating advanced MPCVD manufacturing capabilities.

The following hard data points were extracted from the analysis of diamond and BDD properties:

ParameterValueUnitContext
Pure Diamond ResistivityUp to 1012Ω·mInsulator state, necessitating doping
C-C Bond Length0.154nmFundamental diamond structure
C-C Bond Angle109°28’°Ortho-tetrahedral structure
C-C Bond Energy347kJ/molContributes to high chemical stability
Lattice Constant (298 K)0.356683nmFace-centered cubic structure
Sound Wave Propagation SpeedUp to 18.2km/sHigh elastic modulus (Acoustic applications)
Optimal Boron Doping Concentration2g/LExample concentration for maximum potential window (Boron source mass concentration)
Optical Transmittance Range0.22”mVacuum UV to far infrared (Window material applications)

The paper analyzes the primary methods for preparing BDD films, highlighting the trade-offs between quality, scale, and complexity.

  1. Chemical Vapor Deposition (CVD) Doping:

    • Microwave Plasma Chemical Vapor Deposition (MW-PCVD): The most widely used method for high-quality diamond film deposition. Advantages include no electrode contamination, wide operating pressure range, high plasma density, and the ability to generate large volumes of uniform plasma. (Disadvantages: High equipment price, difficult to deposit large area films, low deposition rate).
    • Hot Filament Chemical Vapor Deposition (HFVCD): Simpler equipment, suitable for preparing large-size BDD membrane electrodes. (Disadvantages: Poor stability, easy contamination, unsuitable for high-quality films).
    • DC Hot-Cathode CVD: Used specifically for preparing BDD films on P-type (100) silicon substrates, often utilizing liquid trimethyl borate as the boron source.
  2. Ion Implantation Method:

    • Involves injecting boron ions directly into an already prepared diamond film using electric field acceleration.
    • High efficiency, but high-energy injection causes severe surface damage due to the tight carbon-carbon bond structure.
    • Requires subsequent annealing processes to remove the surface damage layer and prevent graphitization. Multiple ion implantation/annealing cycles are typically required for P-type semiconductor preparation.

6CCVD’s advanced MPCVD platform directly addresses the limitations (cost, scale, deposition rate, quality) inherent in laboratory-scale BDD production, enabling commercialization and advanced research.

To replicate or extend the high-performance electrochemical research detailed in the paper, 6CCVD recommends the following materials:

Research Requirement6CCVD Material SolutionRationale
High-Quality, Large Area Electrodes (Wastewater)Heavy Boron-Doped Polycrystalline Diamond (PCD)Offers superior chemical stability and corrosion resistance over metal electrodes. Our PCD wafers (up to 125mm) overcome the size limitations of typical MW-PCVD systems, enabling commercial scale-up.
High-Sensitivity Sensing (Trace Detection)Boron-Doped Single Crystal Diamond (SCD)SCD provides the highest structural purity and lowest defect density, crucial for minimizing background currents and maximizing the potential window required for high-fidelity trace analysis.
High-Density Doping/Semiconductor ApplicationsCustom Boron-Doped Diamond (BDD)We offer precise control over the B/C ratio during growth to achieve the specific doping concentrations (e.g., optimal 2 g/L equivalent) necessary for maximizing electrochemical performance.

The paper highlights the need for specialized electrode formats (rotating ring-disk electrodes, BDD/Nb mesh, microelectrodes). 6CCVD provides comprehensive fabrication services to meet these complex geometric and integration needs.

  • Custom Dimensions and Shaping: We provide plates and wafers up to 125mm in diameter (PCD) and offer precision laser cutting and etching services to create complex geometries (disks, rings, meshes, microelectrode arrays) required for advanced electrochemical cells.
  • Thickness Control: We offer BDD films with precise thickness control, ranging from 0.1 ”m to 500 ”m (SCD/PCD), allowing researchers to optimize material usage and electrical properties for specific applications (e.g., thin films for sensing, thick films for high-power anodes).
  • Integrated Metalization: We offer internal metalization capabilities (Au, Pt, Pd, Ti, W, Cu) to ensure robust, low-resistance electrical contacts, which is critical for integrating BDD electrodes into functional devices like sensors and industrial reactors. The ability to apply stable metal layers (e.g., Ti/Pt/Au stacks) directly to the BDD surface simplifies device fabrication.
  • Surface Finish: For high-sensitivity applications like trace compound detection, a low background current is essential. Our advanced polishing achieves surface roughness of Ra < 5nm for inch-size PCD and Ra < 1nm for SCD, ensuring minimal surface defects and maximum inertness.

The success of BDD research hinges on optimizing the preparation process and doping concentration.

  • Process Optimization: 6CCVD’s in-house PhD team specializes in MPCVD growth parameters. We offer consultation and collaborative engineering support to define the optimal material composition, structure, and preparation conditions necessary to maximize the potential window and catalytic activity for similar Electrochemical Wastewater Treatment and Trace Sensing projects.
  • Global Logistics: We ensure reliable, global delivery of sensitive diamond materials, with DDU (Delivered Duty Unpaid) as the default shipping method and DDP (Delivered Duty Paid) available upon request.

For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.

View Original Abstract

Thanks to its unique structure, diamond has many excellent properties, such as high hardness, low birefringence, high thermal conductivity, good chemical stability, etc., but pure diamond has extremely high resistivity (up to 1012 Ω∙m ), which is an insulator, so it is usually doped to expand the application of diamond in the electrochemical field. B atoms have a very small radius, which is an ideal material for doping diamond, and B-doped diamond has good electrical conductivity. In this paper, on the basis of introducing the phase composition and structure of boron-doped diamond (BDD) film, the common methods for preparing BDD film are analyzed, and the application status and prospect of its application in electrochemistry and other fields are summarized.