The Frequency Domain Thermoreflectance Technique for Thermal Property Measurements.

Area of Science:

• Materials Science
• Physics
• Nanotechnology

Background:

• The frequency domain thermoreflectance (FDTR) technique offers non-destructive thermal characterization with microscale resolution.
• Accurate thermal property measurement is vital for optimizing materials, especially in advanced electronics and energy applications.

Purpose of the Study:

• To provide detailed protocols for implementing FDTR for local thermal conductivity measurements.
• To analyze the influence of laser parameters and error sources on FDTR measurements.
• To investigate thermal conductivity at interfaces using FDTR.

Main Methods:

• Utilizing a pump laser to induce modulated temperature changes and a probe laser to detect thermal response.
• Fitting a thermal model to experimental thermoreflectance data to extract thermal properties.
• Performing thermal conductivity imaging near an interface between single-crystal silicon substrates.

Main Results:

• Detailed protocols for FDTR implementation and uncertainty quantification are presented.
• A 3% suppression in thermal conductivity was observed at the interface between two single-crystal silicon substrates compared to bulk values.
• The study demonstrates FDTR's capability to probe localized interface thermal properties.

Conclusions:

• FDTR is a powerful tool for microscale thermal characterization and imaging.
• Understanding interface thermal conductivity is critical for heat flow management in materials.
• FDTR can facilitate the study of grain boundaries in thermoelectric materials for performance optimization.