Mapping Elevated Temperatures with a Micrometer Resolution Using the Luminescence of Chemically Stable Upconversion...

Area of Science:

• Nanotechnology
• Optical Thermometry
• Materials Science

Background:

• Temperature-sensitive luminescence of nanoparticles enables remote thermometry.
• Nanothermometers offer high spatial resolution for temperature mapping.
• High-resolution thermometry above 373 K remains a challenge.

Purpose of the Study:

• To develop and validate a nanothermometry method for high spatial resolution temperature mapping above 373 K.
• To address spectral distortions affecting measurements at elevated temperatures.
• To enhance the accuracy and range of nanothermometry for microelectronics and photonics.

Main Methods:

• Utilized chemically stable upconversion nanoparticles and confocal microscopy.
• Tested the nanothermometry method on a microelectromechanical heater.
• Developed a procedure to correct for spectral distortions caused by excitation, scattering, and reflection.

Main Results:

• Achieved high spatial resolution nanothermometry beyond 500 K.
• Demonstrated a precision of 1-4 K in temperature measurements.
• Identified and corrected spectral distortions arising from nanoscale photonic inhomogeneities and optical effects.

Conclusions:

• Successfully extended high-resolution nanothermometry to elevated temperatures (>500 K).
• The developed correction procedure significantly improves measurement accuracy.
• This advancement is crucial for applications in micro- and nanoelectronics and other fields with complex photonic substrates.