Stacking Lanthanide-MOF Thin Films to Yield Highly Sensitive Optical Thermometers

Area of Science:

• Materials Science
• Nanotechnology
• Chemistry

Background:

• Optical thermometers with remote readout capabilities are crucial for diverse applications.
• Lanthanide-based luminescent materials, specifically Europium(III) and Terbium(III), show promise for optical sensing.
• Continuous, thin-film sensors are desirable for easy integration and fast response.

Purpose of the Study:

• To fabricate highly sensitive, optical thermometers using lanthanide-based supramolecular Metal-Organic Frameworks (SURMOFs).
• To investigate the temperature-sensing photoluminescence behavior of these novel materials.
• To enhance thermal sensitivity through controlled energy transfer and advanced architectures.

Main Methods:

• Utilized a layer-by-layer (LbL) approach within liquid-phase epitaxy to create continuous, low-thickness lanthanide-MIL-103 SURMOFs.
• Employed MOF-on-MOF heteroepitaxy to engineer sophisticated supramolecular architectures.
• Controlled film thickness and quality to achieve high transmittance and optical readout.

Main Results:

• Successfully fabricated continuous, low-thickness lanthanide-SURMOFs with remarkable temperature-sensing photoluminescence.
• Demonstrated naked-eye readability of temperature changes via luminescence.
• Achieved enhanced thermal sensitivity above 120 K by controlling energy transfer between Tb(III) and Eu(III).
• Obtained high transmittance by precise control over film properties.

Conclusions:

• Lanthanide-MIL-103 SURMOFs are effective materials for developing highly sensitive optical thermometers.
• The MOF-on-MOF heteroepitaxy approach enables fine-tuning of sensor performance, particularly thermal sensitivity.
• These SURMOF thermometers offer a promising solution for remote, optical temperature monitoring with visual readout.