Y₂Mo₄O₁₅:Er³⁺/Tm³⁺/Yb³⁺ Nanophosphors for High-Sensitivity Optical Temperature Sensing

Area of Science:

• Materials Science
• Nanotechnology
• Optical Sensing

Background:

• Noncontact optical nanothermometers offer high temperature resolution, sensitivity, rapid response, and stability.
• Upconversion nanoparticles (UCNPs) are promising materials for thermometry due to their unique optical properties.

Purpose of the Study:

• To synthesize and characterize Y2Mo4O15 based UCNPs codoped with Er3+, Tm3+, and Yb3+ for optical thermometry.
• To evaluate the temperature-sensing capabilities of these UCNPs using the fluorescence intensity ratio technique.

Main Methods:

• Sol-gel synthesis of Y2Mo4O15 nanophosphors codoped with varying concentrations of Yb3+.
• Characterization of crystal structure, morphology, and luminescence properties.
• Temperature-dependent luminescence measurements (300-520 K) using 975 nm laser excitation.

Main Results:

• Intense upconversion luminescence observed, attributed to Er3+ and Tm3+ energy transitions.
• Optimal relative sensitivity (Sr = 2.18% K-1) achieved at 300 K using the I700/I806 ratio from thermally coupled levels.
• Minimum temperature uncertainty (δT = 0.26 K) demonstrated, highlighting excellent thermometric performance.

Conclusions:

• The synthesized Y2Mo4O15 UCNPs exhibit superior performance for optical nanothermometry.
• Synergistic interplay of multiple luminescent centers enhances temperature-sensing capabilities.
• These nanomaterials provide a foundation for developing advanced, next-generation temperature nanosensors.