FDTR Thermal Conductivity Measurement System
Frequency-Domain Thermoreflectance (FDTR) thermal conductivity measurement system, independently developed by Metathermo (Suzhou) Energy Technology Co., Ltd., is a non-contact, micro/nanoscale thermophysical property characterization platform based on the optothermal detection principle. The system employs two laser beams (pump + probe) to excite and detect periodic temperature rise signals on the surface of a metal transducer/sample. By extracting the variation of thermoreflectance with modulation frequency, it derives the thermal conductivity, thermal diffusivity, and interfacial thermal resistance of the material. Covering a wide range of testing requirements from thin films and bulk materials to micro/nanoscale heterostructures, the system is well suited for research on thermal management materials, 2D electronic devices, thermoelectric materials, and low-dimensional physics.
System Photo
Working Principle
Key Performance Parameters
| Item | Specification |
|---|---|
| Measurement Mode | Frequency Domain Thermoreflectance (FDTR), single / dual wavelength optional |
| Pump Laser Modulation Frequency Range | Typical 10 kHz – 20 MHz (continuous frequency sweep) |
| Thermal Conductivity Measurement Range | ~0.1 – 2000 W/(m·K) (depends on sample structure and fitting model) |
| Thermal Diffusivity Measurement Range | 10⁻⁸ – 10⁻⁴ m²/s |
| Spatial Resolution | Optical diffraction limit, typical spot size ~5–10 μm (sub-micron achievable with objective lens) |
| Temperature Range | Room temperature – 500 °C (low / high-temperature sample stage extension optional) |
| Interface Thermal Resistance Sensitivity | Resolvable down to ~10⁻⁸ m²·K/W level |
| Sample Requirements | Metal transducer layer (Al / Au / Pt, etc.) or sufficient thermoreflectance on surface |
| Data Acquisition | Lock-in amplifier real-time demodulation of 1ω/2ω signals, auto frequency sweep + fitting |
| Control Software | Integrated optical alignment, frequency sweep, parameter inversion and report generation |
System Components
| Module | Description |
|---|---|
| Optical Engine | CW pump laser + probe laser; acousto-optic / electro-optic modulator for frequency modulation |
| Microscopic Optical Path | Coaxial incidence, high-NA objective lens focusing; confocal design ensures signal collection efficiency |
| Motion & Positioning | High-precision motorized XYZ stage, nanometer stepping, supports multi-point array scanning |
| Signal Detection | Photodetector + lock-in amplifier to extract weak 2ω thermoreflectance signal |
| Environmental Control | Optional nitrogen purge chamber or vacuum sample cell to suppress convection and oxidation |
| Analysis Software | Built-in multi-layer heat conduction model (including interface thermal resistance); one-click fitting to output κ, α, R_th |
Technical Highlights
Non-contact, Non-destructive Measurement
No microfabricated electrodes or temperature sensors need to be fabricated on samples. Thermal properties are obtained purely via optical probing, making it especially suitable for delicate thin films, 2D material heterostructures, micro/nano devices and other samples incompatible with conventional 3ω or TTR processes.
Full-spectrum Thermal Response Analysis
Continuous frequency sweeps yield complete curves of thermoreflectance phase/amplitude versus modulation frequency. A single measurement can simultaneously extract bulk thermal conductivity, thermal diffusivity and interface thermal resistance, delivering far richer information than single-point steady-state methods.
Micro-area Mapping Capability
Paired with a motorized stage, 2D thermal conductivity distribution scanning can be performed across the sample surface to visualize spatial variations in material uniformity, defect distribution or interfacial bonding quality.
Complementary to the 3-Omega Platform
MetaThermo offers both 3-Omega and FDTR systems. The 3-Omega method excels at rapid measurements for bulk solids / liquids / irregular surfaces, while FDTR specializes in high-resolution characterization of micro-nano thin films and interfaces. Combined, they support full-scale thermal property research from macroscopic down to atomic scales.
Validated for Cutting-edge Research
FDTR is widely adopted for thermal transport characterization of 2D materials including graphene, hBN and TMDCs, as well as interface thermal resistance analysis for phase-change memory, thermal interface materials (TIM), polymer composites and related fields.
Typical Applications
- 2D Materials & Van der Waals Heterostructures: in-plane / out-of-plane thermal conductivity of monolayer / few-layer graphene, MoS₂, WSe₂
- Chip Thermal Management: thermal resistance and thermal conductivity of thermal interface materials (TIM), underfill, thermal grease
- Thermoelectric Materials: separation of in-plane thermal diffusivity and lattice thermal conductivity for thin-film thermoelectric legs
- Energy Devices: microscale thermal properties of solid-state battery electrolytes and charge transport layers in perovskite solar cells
- Functional Coatings: joint extraction of thickness and thermal conductivity for DLC, TBC (thermal barrier coatings), and CVD diamond films
- Fundamental Physics: phonon transport, interfacial phonon coupling, and size-effect modulation of thermal conduction
Cooperation Cases
