Unusually Effective Blue-to-UVC Upconversion of Pr³⁺-Doped Sr₃Lu(PO₄)₃ and Ba₃Lu(PO₄)₃ Phosphors: A Comparative Study

Area of Science:

• Materials Science
• Solid-State Chemistry
• Photochemistry

Background:

• Growing antimicrobial resistance necessitates novel disinfection methods.
• Luminophores converting visible light to ultraviolet C (UVC) radiation offer a promising alternative.
• UVC radiation is effective for sterilization and disinfection.

Purpose of the Study:

• To synthesize and characterize novel Pr³⁺-activated phosphors for UVC generation.
• To investigate the photoluminescent and upconversion properties of these novel materials.
• To evaluate their potential for disinfection and other applications.

Main Methods:

• Synthesis of A₃Lu(PO₄)₃ (A = Sr, Ba) phosphors via the Pechini method.
• Crystallographic analysis to confirm cubic structure (space group <i>I4̅3d</i>).
• Spectroscopic measurements (excitation, emission, decay times) under synchrotron and visible-light excitation; UVC upconversion evaluation.

Main Results:

• Efficient 5d-4f emission (240-340 nm) observed in both Sr and Ba phosphates.
• Ba₃Lu(PO₄)₃:Pr³⁺ demonstrated a 20-fold enhancement in UVC upconversion compared to YPO₄:Pr³⁺.
• The materials exhibit potential for visible-to-ultraviolet upconversion.

Conclusions:

• Novel Pr³⁺-activated phosphates exhibit efficient UVC generation via upconversion.
• Ba₃Lu(PO₄)₃:Pr³⁺ is a highly efficient visible-to-UVC upconversion matrix.
• These phosphors hold significant potential for sterilization, disinfection, photocatalysis, and phototherapy.