Deciphering Defect-Mediated Anti-Thermal Quenching Multimodal Luminescence for Information Encryption

Area of Science:

• Materials Science
• Solid State Chemistry
• Luminescence

Background:

• Multimodal luminescent materials are key for optical information encryption.
• Achieving high-performance multimodal luminescence with anti-thermal quenching (ATQ) is a significant challenge.

Purpose of the Study:

• To develop novel SrZnP2O7:RE (RE = Sm3+, Dy3+, Tb3+, Tm3+) phosphors with tunable multicolor emissions and ATQ properties.
• To investigate the role of defect engineering and charge compensation in modulating luminescence.

Main Methods:

• Synthesis of SrZnP2O7:RE phosphors with varying charge compensators (Li+, Na+, K+).
• Characterization of multimodal luminescence: photoluminescence (PL), radioluminescence (RL), mechanoluminescence (ML), thermoluminescence (TL), and persistent luminescence (PersL).
• Analysis of trap distribution and defect states influencing luminescence and ATQ behavior.

Main Results:

• Phosphors exhibit multimodal luminescence spanning 350-750 nm.
• Charge compensation precisely regulated trap density, enhancing PL, quantum efficiency, RL intensity, and X-ray afterglow.
• Engineered deep traps in Sm/Dy/Tm-doped phosphors demonstrated exceptional ATQ behavior.

Conclusions:

• Defect engineering and charge compensation are critical for tailoring multimodal luminescence and ATQ properties.
• The developed phosphors show great promise for X-ray imaging and high-security anti-counterfeiting/encryption.
• This work provides insights into defect-luminescence relationships and a framework for designing advanced optical materials.