Modulating anti-thermal and concentration quenching for enhanced dysprosium emission.

Area of Science:

• Materials Science
• Solid-State Chemistry
• Luminescence

Background:

• Thermal-quenching (TQ) effect reduces phosphor luminosity at high temperatures, impacting light output stability.
• Color consistency, crucial for temperature tolerance in the CIE diagram, is often overlooked in phosphor research.
• Developing phosphors with both high thermal stability and consistent color output is essential for advanced lighting.

Purpose of the Study:

• To investigate Tm3+- and Dy3+-doped Sr3LaAl3B4O15 (SLAB) phosphors as potential white light-emitting materials.
• To evaluate the thermal stability and color consistency of these novel phosphors.
• To understand the energy transfer mechanisms contributing to anti-TQ behavior and suppressed concentration quenching.

Main Methods:

• Synthesis and comprehensive characterization of Tm3+ and Dy3+ doped SLAB phosphors.
• Techniques employed: X-ray diffraction, Rietveld refinement, TEM, SEM, ESR, and diffuse reflectance spectroscopy.
• Analysis of energy transfer (ET) modulation between Tm3+ and Dy3+ ions.

Main Results:

• Observed effective anti-TQ behavior and intrinsic suppression of concentration quenching due to ET modulation between Tm3+ and Dy3+.
• Achieved high ET efficiencies (78.28%) via electric dipole interactions and demonstrated viability of high Tm3+ doping.
• Demonstrated superior thermal stability with high anti-TQ performance (105.8% at 400 K) and low chromaticity shift (ΔEs = 10.31 × 10−3).

Conclusions:

• Tm3+- and Dy3+-doped SLAB phosphors exhibit enhanced photoluminescence and excellent thermal stability, outperforming typical Ln3+ ion behaviors.
• These phosphors show promising anti-TQ performance and color stability, comparable to commercial phosphors.
• SLAB:Tm3+,Dy3+ phosphors are suitable for warm-white LED applications, offering high color rendering (Ra ≥ 86.4) and stable output.