An up-conversion Ba₃In(PO₄)₃:Er³⁺/Yb³⁺ phosphor that enables multi-mode temperature measurements and wide-gamut...

Area of Science:

• Materials Science
• Optical Physics
• Solid-State Chemistry

Background:

• Current fluorescent materials for optical thermometry suffer from poor thermochromic performance, limiting their practical use.
• Developing materials with enhanced temperature-dependent luminescence is crucial for advanced sensing applications.

Purpose of the Study:

• To synthesize and characterize a novel phosphor, Ba3In(PO4)3:Er/Yb, for optical temperature measurement.
• To investigate its thermochromic properties and explore its potential in thermal imaging and optical encryption.

Main Methods:

• Synthesis of Ba3In(PO4)3:Er/Yb phosphor with high Yb3+ doping concentration.
• Characterization of up-conversion luminescence properties.
• Implementation of four fluorescence thermometry modes (intensity ratio, color shift, decay lifetime) in the 303-603 K range.
• Demonstration of temperature mapping and optical encryption on a metal surface.

Main Results:

• The synthesized phosphor exhibited a wide color gamut up-conversion luminescence from red to green, induced by composition and temperature.
• Four distinct fluorescence thermometry methods were successfully realized.
• The highest sensitivity (Sr) value achieved was 0.977% K-1.
• Successful demonstration of temperature mapping with multiple optical encryptions based on color changes.

Conclusions:

• The Ba3In(PO4)3:Er/Yb phosphor demonstrates excellent thermochromic performance and suitability for optical temperature measurement.
• This material holds significant potential for applications in thermal imaging, temperature visualization, and optical encryption.