Er³⁺-activated Ba₂V₂O₇ upconversion nanosheets for dual-mode temperature sensing

Area of Science:

• Materials Science
• Solid State Chemistry
• Luminescence Spectroscopy

Background:

• Non-contact thermometry using luminescence intensity ratio (LIR) is crucial.
• Limited availability of sensitive Er³⁺-doped phosphors hinders progress.
• Developing novel phosphors with enhanced luminescence and sensitivity is essential.

Purpose of the Study:

• To synthesize and characterize Ba₂V₂O₇:Er³⁺ phosphors.
• To investigate their upconversion and down-shifting luminescence properties.
• To evaluate their potential for luminescence thermometry.

Main Methods:

• Sol-gel synthesis aided by citric acid for Ba₂V₂O₇:Er³⁺.
• Investigation of luminescence under UV and 980 nm laser excitation.
• Analysis of luminescence intensity ratio (LIR) for temperature sensing.

Main Results:

• Synthesized Ba₂V₂O₇:Er³⁺ phosphors exhibit pale green broadband emission under UV light (V₂O₇^2-) and green upconversion emission under 980 nm laser (Er³⁺).
• The LIR between thermally coupled energy levels (TCELs) and non-thermally coupled energy levels (NTCELs) of Er³⁺ was analyzed.
• The material demonstrated temperature-sensing capabilities.

Conclusions:

• Ba₂V₂O₇:Er³⁺ phosphors are successfully synthesized via a sol-gel method.
• The material exhibits distinct UV and NIR-excited luminescence, suitable for thermometry.
• Ba₂V₂O₇:Er³⁺ nanosheets show potential for non-contact temperature sensing applications.