Demonstration of electric double layer gating under high pressure by the development of field-effect diamond anvil cell
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2020-06-01 |
| Journal | Applied Physics Letters |
| Authors | Shintaro Adachi, Ryo Matsumoto, Sayaka Yamamoto, Takafumi D Yamamoto, Kensei Terashima |
| Institutions | University of Tsukuba, National Institute for Materials Science |
| Citations | 4 |
| Analysis | Full AI Review Included |
Technical Documentation & Analysis: Field-Effect Diamond Anvil Cells (EDLT-DAC)
Section titled âTechnical Documentation & Analysis: Field-Effect Diamond Anvil Cells (EDLT-DAC)âThis document analyzes the research paper, âDemonstration of Electric Double Layer Gating under High Pressure by the Development of Field-Effect Diamond Anvil Cell,â focusing on the critical role of custom MPCVD diamond materials and outlining 6CCVDâs capabilities to support and advance this high-pressure, quantum materials research.
Executive Summary
Section titled âExecutive SummaryâThe development of the Electric Double Layer Transistor-Diamond Anvil Cell (EDLT-DAC) represents a significant advancement in controlling material properties under extreme conditions. 6CCVD is uniquely positioned to supply the custom diamond components required for the replication and extension of this technology.
- Novel Device Integration: Successful combination of Electric Double Layer Transistor (EDLT) gating with a Diamond Anvil Cell (DAC) to tune carrier density in materials (Bismuth thin film) under high pressure.
- Critical Diamond Components: The device relies on custom-fabricated diamond anvils: Boron-Doped Diamond (BDD) serving as micro-scale electrodes and high-purity, un-doped diamond acting as the insulating layer/substrate.
- Extreme Operating Conditions: Demonstrated field-effect tuning up to 1.95 GPa at room temperature (RT), with resistance measurements validated down to 2 K.
- EDL Stabilization: High pressure was found to stabilize the Electric Double Layer (EDL), suggesting a pathway for developing novel, stable field-effect devices (e.g., transistors) operating at high pressure and room temperature.
- Low Leakage Performance: Achieved excellent electrical isolation, maintaining leakage currents below 20 nA, crucial for stable EDL gating.
- Application Potential: This EDLT-DAC methodology is a powerful tool for exploring unknown physical phenomena, particularly High Transition-Temperature Superconductivity (HTS).
Technical Specifications
Section titled âTechnical SpecificationsâThe following hard data points were extracted from the research paper, detailing the operational parameters and material characteristics of the EDLT-DAC device.
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Maximum Applied Pressure (P) | 1.95 | GPa | Highest pressure achieved during EDL gating experiments. |
| Operating Temperature Range | 300 K down to 2 K | K | Range for electrical resistance measurements. |
| Applied Gate Voltage (VG) | 0 or 1 | V | Voltage used to induce the Electric Double Layer (EDL). |
| Maximum Leakage Current | < 20 | nA | Monitored through the ionic liquid electrolyte (DEME-TFSI). |
| Upper Anvil Culet Diameter | 600 | ”m | Standard dimension for high-pressure generation. |
| Gasket Material | Pt(80%)-Ir(20%) | Alloy | Used as both sealing gasket and electrochemically stable gate electrode. |
| Gasket Thickness | 200 | ”m | Thickness of the Pt-Ir sheet. |
| Bismuth (Bi) Film Thickness | 60 - 70 | nm | Sample thickness, prepared by vacuum vapor deposition. |
| Estimated Glass Transition Pressure (PG) | 1.54 to 1.92 | GPa | PG of the ionic liquid (DEME-TFSI) at 300 K, correlating with EDL stabilization. |
| Initial Bi Film Resistance (R0) | 132 to 310 | Ω | Initial resistance values at t = 0 for various samples. |
Key Methodologies
Section titled âKey MethodologiesâThe EDLT-DAC device relies on precise fabrication and assembly of custom diamond components to achieve simultaneous high-pressure generation and electrical gating.
- Custom Diamond Anvil Fabrication: The lower diamond anvil was custom-fabricated to integrate electrical functionality, utilizing micro-scale Boron-Doped Diamond (BDD) regions as source/drain electrodes and un-doped diamond as the insulating layer.
- Sample Preparation: A Bismuth (Bi) thin film (60-70 nm) was deposited onto the polished surface of the lower diamond anvil via vacuum vapor deposition.
- Gasket and Gate Electrode: A 200 ”m thick sheet of Pt(80%)-Ir(20%) alloy was employed as the gasket. Due to its electrochemical stability, the gasket also served as the gate electrode for the EDLT structure.
- Pressure Medium/Electrolyte: The ionic liquid DEME-TFSI was injected into the sample space, functioning simultaneously as the pressure transmitting medium and the electrolyte necessary for forming the Electric Double Layer (EDL).
- Pressure Generation and Measurement: High pressure (up to 1.95 GPa) was generated by pressing the 600 ”m culet upper anvil. Pressure was monitored in situ using the Râ ruby fluorescence line method.
- Electrical Gating and Measurement: A gate voltage (VG = 1 V) was applied between the Pt-Ir gasket (gate) and the Bi film (source), inducing carriers. Electrical resistance was measured using a standard four-probe method across the Bi film.
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & CapabilitiesâThe EDLT-DAC research highlights the critical need for highly specialized, high-purity, and precisely fabricated diamond components. 6CCVD is the ideal partner to supply the materials necessary to replicate and advance this high-pressure field-effect research.
Applicable Materials
Section titled âApplicable Materialsâ| Research Requirement | 6CCVD Material Solution | Key Capability Match |
|---|---|---|
| Electrodes | Heavy Boron-Doped Diamond (BDD) | High conductivity, necessary for micro-scale source/drain electrodes in the DAC. We offer doping levels optimized for metallic behavior. |
| Insulating Layer/Substrate | Optical Grade Single Crystal Diamond (SCD) | Required for high electrical isolation (low leakage current < 20 nA) and superior thermal management under pressure. |
| Custom Anvil Substrate | SCD or High-Purity PCD Substrates | Available in thicknesses up to 10 mm and custom dimensions, providing the mechanical strength required for GPa pressures. |
Customization Potential
Section titled âCustomization PotentialâThe successful fabrication of the EDLT-DAC depends entirely on micro-scale precision and specialized integration, areas where 6CCVD excels.
- Custom Dimensions and Geometry: The paper utilized a 600 ”m culet anvil and micro-scale electrodes. 6CCVD specializes in producing custom diamond plates and wafers up to 125 mm (PCD) and offers precision laser cutting and shaping services to achieve the exact culet geometry and electrode patterns required for DAC applications.
- Advanced Polishing for Thin Films: The Bi film was only 60-70 nm thick. Successful deposition and reliable EDL formation require an atomically flat surface. 6CCVD guarantees ultra-low roughness polishing (Ra < 1 nm for SCD), ensuring optimal interface quality for thin film deposition and field-effect experiments.
- Integrated Metalization Services: While the paper used a Pt-Ir gasket as the gate, the diamond electrodes require robust metal contacts. 6CCVD offers in-house, custom metalization stacks (Au, Pt, Pd, Ti, W, Cu) tailored for high-pressure, electrochemical stability, and cryogenic environments (down to 2 K). We can develop specific stacks to interface with ionic liquids or high-pressure media.
- Thickness Control: We provide SCD and PCD layers with precise thickness control, ranging from 0.1 ”m up to 500 ”m, allowing researchers to optimize the diamond electrode and insulating layer thickness for specific electrical and mechanical requirements.
Engineering Support
Section titled âEngineering Supportâ6CCVDâs in-house team of PhD material scientists and engineers provides comprehensive support for complex high-pressure and quantum materials projects.
- Material Selection Consultation: Our experts can assist researchers in selecting the optimal diamond grade (e.g., nitrogen concentration, defect density) and doping level (BDD) to maximize electrode performance and minimize leakage current in similar High-Pressure Field-Effect projects.
- Design for Manufacturability: We collaborate with research teams to translate complex EDLT-DAC designs into manufacturable diamond components, ensuring compatibility with existing DAC systems and high-pressure protocols.
- Global Logistics: We ensure reliable, global shipping (DDU default, DDP available) of sensitive, high-value diamond components directly to your lab.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
We have developed an approach to control the carrier density in various materials under high pressure by the combination of an electric double layer transistor (EDLT) and a diamond anvil cell (DAC). In this study, this âEDLT-DACâ was applied to a Bi thin film, and here, we report the field effect under high pressure in the material. Our EDLT-DAC is a promising device for exploring unknown physical phenomena such as high transition-temperature superconductivity.