Solid solutions of InSb-ZnS heterosystem — primary converters of semiconductor sensors
At a Glance
Section titled “At a Glance”| Metadata | Details |
|---|---|
| Publication Date | 2021-01-01 |
| Journal | Omsk Scientific Bulletin |
| Authors | I. A. Kirovskaya, N. V. Chernous, Е. В. Миронова, А. О. Ekkert |
| Institutions | ORCID, Omsk State Technical University |
| Citations | 2 |
| Analysis | Full AI Review Included |
Technical Documentation & Analysis: Diamond Materials for Advanced Semiconductor Sensors
Section titled “Technical Documentation & Analysis: Diamond Materials for Advanced Semiconductor Sensors”Reference Paper Analysis: Solid Solutions of the InSb-ZnS Heterosystem as Primary Transducers for Semiconductor Sensors
Executive Summary
Section titled “Executive Summary”This research details the synthesis and characterization of InSb-ZnS solid solutions for use as primary transducers in semiconductor gas sensors, specifically targeting basic gases like ammonia (NH3). 6CCVD identifies this application space as a prime opportunity for leveraging the superior performance characteristics of MPCVD diamond.
- Material Synthesis: Solid solutions of (InSb)x(ZnS)1-x were successfully synthesized via isothermal diffusion, exhibiting a cubic sphalerite structure.
- Surface Chemistry: The material surfaces are characterized as weakly acidic (pHiso ranging from 5.7 to 6.6), correlating with high surface activity toward basic gases.
- Sensing Application: The materials, particularly those with lower pHiso values, are recommended for manufacturing sensors detecting micro-impurities of basic gases (e.g., NH3).
- Correlation Established: The study confirms a valuable correlation between bulk properties (lattice parameter, band gap ΔE) and surface properties (pHiso), facilitating streamlined material selection for sensor development.
- 6CCVD Value Proposition: While InSb-ZnS offers a functional semiconductor, Boron-Doped Diamond (BDD) supplied by 6CCVD provides unparalleled chemical inertness, stability in harsh environments, and superior electrochemical performance, making it the ideal material for next-generation, high-reliability gas and electrochemical sensors.
Technical Specifications
Section titled “Technical Specifications”The following hard data points were extracted from the experimental section and results, defining the material parameters and processing conditions used in the research.
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Crystal Structure | Cubic | Sphalerite | Confirmed structure of the solid solutions |
| Specific Surface Area (Sspec) | 0.31 - 1.35 | m2/g | Range for fine-dispersed powders |
| Dominant Particle Size (ncp) | 1 - 2 | µm | Interval of dominating particle size |
| Lattice Parameter (a) Range | 6.48 - 5.41 | Å | Varies across the full composition range (InSb to ZnS) |
| X-ray Density (ρ) Range | 5.7 - 4.1 | g/cm3 | Varies across the full composition range |
| Band Gap (ΔE) Range | 0.18 - 3.67 | eV | Correlates with composition (InSb to ZnS) |
| Isoelectric Point (pHiso) Range | 5.7 - 6.6 | N/A | Surface acidity range (weakly acidic) |
| Vacuum Thermal Treatment Pressure | ≈ 2.3 x 10-4 | Pa | High vacuum processing condition |
| Vacuum Thermal Treatment Temperature | 573 - 673 | K | Required for surface cleaning/degassing (300 °C to 400 °C) |
| Composition of Interest (Extremum) | 77 | mol.% ZnS | Composition showing extremal changes in properties |
Key Methodologies
Section titled “Key Methodologies”The synthesis and characterization of the InSb-ZnS solid solutions relied on a combination of high-temperature processing and advanced analytical techniques.
- Synthesis: Solid solutions were obtained using a specialized methodology based on isothermal diffusion and a controlled temperature heating program, utilizing the known physical and chemical properties of the initial binary compounds (InSb, ZnS).
- Structural Characterization (XRD): X-ray diffraction (XRD) was performed using a BRUKERAXS D8 Advance Powder Diffractometer (CuK radiation, λ=0.154056 nm) to confirm the sphalerite structure, calculate lattice parameters (a), and determine interplanar distances (dhkl).
- Microscopy (SEM/TEM): Microscopic analysis utilized KN 8700 and Micromed “POLAR-3” instruments. Electron microscopy was performed using a JSM-5700 Scanning Electron Microscope (SEM) equipped with a JED-2300 Energy Dispersive Spectroscopy (EDS) attachment for elemental composition verification.
- Surface Chemical Analysis (IR Spectroscopy): Chemical composition of the surfaces was determined using Fourier-transform infrared (FTIR) spectroscopy via an Infra-LUM FT-02 spectrometer with an MNПВО (Attenuated Total Reflection) attachment (400-4000 cm-1 range).
- Acidity Determination: Acid-base properties of the surfaces were studied using hydrolytic adsorption methods to determine the pH of the isoelectric state (pHiso).
6CCVD Solutions & Capabilities
Section titled “6CCVD Solutions & Capabilities”The research demonstrates a clear need for robust, chemically stable, and highly controllable semiconductor materials for gas sensing. 6CCVD’s MPCVD diamond materials offer a significant performance upgrade over traditional II-V/II-VI compounds like InSb-ZnS, particularly in applications requiring long-term stability and resistance to harsh chemical environments.
Applicable Materials
Section titled “Applicable Materials”To replicate or significantly extend this research into commercial-grade, high-performance sensors, 6CCVD recommends the following materials:
| 6CCVD Material | Description & Relevance to Sensing | Customization Potential |
|---|---|---|
| Heavy Boron-Doped Diamond (BDD) | Ideal for electrochemical and gas sensing. BDD electrodes exhibit extreme chemical inertness, wide potential windows, and high stability, overcoming the chemical limitations of InSb-ZnS. | Custom doping levels (conductivity control) and thin film deposition (0.1 µm - 500 µm). |
| Optical Grade Single Crystal Diamond (SCD) | Used as a high-purity, thermally conductive substrate for integrating active sensing layers (e.g., BDD or other thin films). Excellent thermal management is critical for high-temperature sensor operation (573-673 K). | SCD plates up to 10x10 mm, polished to Ra < 1 nm for epitaxial growth or thin film integration. |
| Polycrystalline Diamond (PCD) Substrates | Cost-effective, large-area substrates (up to 125 mm diameter) for large-scale sensor array manufacturing or high-power applications requiring robust heat spreading. | Custom dimensions up to 125 mm, thicknesses up to 10 mm. Polishing available (Ra < 5 nm for inch-size wafers). |
Customization Potential
Section titled “Customization Potential”The development of advanced primary transducers requires precise control over geometry, surface finish, and electrical contacts—all core competencies of 6CCVD.
- Custom Dimensions and Geometry: While the paper used powders, modern sensors require thin films or structured wafers. 6CCVD provides custom plates and wafers up to 125 mm (PCD) and 500 µm (SCD/PCD) thickness, with precision laser cutting services to achieve unique sensor geometries.
- Ultra-Low Roughness Polishing: Achieving highly controlled surface chemistry (like the pHiso control discussed in the paper) requires exceptional surface quality. 6CCVD guarantees surface roughness of Ra < 1 nm for SCD and Ra < 5 nm for inch-size PCD, ensuring optimal thin-film deposition and surface uniformity.
- Integrated Metalization: Sensor fabrication necessitates reliable electrical contacts. 6CCVD offers in-house metalization services, including deposition of common sensor contact materials such as Ti, Pt, Au, Pd, W, and Cu, tailored to specific adhesion and contact resistance requirements.
Engineering Support
Section titled “Engineering Support”6CCVD’s in-house PhD team specializes in the integration of MPCVD diamond into complex electronic and chemical systems. We offer expert consultation on:
- Material Selection for Gas Sensing: Assisting researchers in transitioning from complex, unstable materials (like InSb-ZnS) to highly robust BDD for ammonia (NH3) and other basic gas detection projects.
- Electrochemical Interface Optimization: Designing BDD surfaces to maximize sensitivity and selectivity for specific analytes, leveraging diamond’s unique surface termination capabilities.
- Thermal Management Solutions: Providing SCD substrates to ensure stable operating temperatures (e.g., 573-673 K) required for high-performance semiconductor sensors.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly. We offer global shipping (DDU default, DDP available) to support your research worldwide.
View Original Abstract
Using the specifically developed method, solid solutions of the AIIIBV (InSb), AIIBVI (ZnS) type semiconductor compounds of various composition (InSb)x (ZnS)1-x have been obtained. According to the results of the performed X-ray, micro-, electron-microscopic studies, the obtained solid solutions are certified as substitutional solid solutions with a cubic sphalerite structure, data on multicomponent diamond-like semiconductors has been enlarged. The chemical composition of the solid solutions surfaces and binary components of the InSb-ZnS system exposed in air and in high-vacuum, high-temperature conditions have been determined. According to the results of the acid-base properties studies, the surfaces of the InSb-ZnS system components exposed in the air are assigned to the weakly acidic region (pHiso<7). The views on the predominant relative contribution of Lewis acid sites and the increased activity of surfaces toward the main gases have been stated and proved. The interrelated consistent patterns of changes in the composition of bulk and surface properties have been established. The practicability of their use for a less labour consuming search for the advanced materials intended for the sensor technology has been shown. The obtained solid solutions, specifically those with the lowest pHiso, are recommended for the manufacture of the sensors for the main gases, particularly NH3, trace contamination.