Enhanced red upconversion luminescence in Er-Tm codoped NaYF4 phosphor

Area of Science:

• Materials Science
• Nanotechnology
• Photonics

Background:

• Upconversion (UC) luminescence is crucial for various photonic applications.
• Controlling UC emission color is essential for advanced material design.
• Rare-earth doped nanomaterials offer tunable optical properties.

Purpose of the Study:

• To investigate enhanced red UC luminescence in Er-Tm codoped NaYF4 microtubes.
• To explore the energy transfer (ET) mechanisms between Er3+ and Tm3+ ions.
• To synthesize NaYF4 microtubes with controlled doping for optimized UC emission.

Main Methods:

• Hydrothermal synthesis of Er-doped and Er-Tm codoped NaYF4 UC hollow microtubes.
• Optical characterization under 1560 nm and 980 nm diode laser excitation.
• Analysis of UC luminescence spectra and intensity variations with Tm3+ concentration.

Main Results:

• Er-doped NaYF4 microtubes exhibited green UC luminescence.
• Er-Tm codoped NaYF4 microtubes showed significantly enhanced red UC luminescence.
• Red UC emission intensity increased with Tm3+ doping concentration.
• UC luminescence properties were consistent under both 1560 nm and 980 nm excitation.

Conclusions:

• Efficient energy transfer between Er3+ and Tm3+ ions is responsible for the enhanced red UC emission.
• NaYF4 microtubes are promising hosts for tunable UC luminescence.
• The findings provide insights into ET mechanisms for designing novel UC materials.