White-light excitable NaYF₄:Nd³⁺ for ultraviolet anti-counterfeiting applications.

Area of Science:

• Materials Science
• Optics
• Chemistry

Background:

• Optical anti-counterfeiting technologies are crucial for security verification.
• Existing luminescent methods face challenges in bright environments due to ambient light interference.

Purpose of the Study:

• To develop a flexible platform for ultraviolet (UV) luminescence in security applications.
• To address the limitations of current anti-counterfeiting strategies in high-ambient light conditions.

Main Methods:

• Introduction of NaYF4:Nd3+ phosphor for UV luminescence.
• Utilizing a two-photon excitation mechanism.
• Testing under intense white-light illumination and daylight conditions.

Main Results:

• NaYF4:Nd3+ exhibits detectable upconversion luminescence at 354 nm.
• The material provides background-free signal detection.
• UV imaging under daylight validated the reliability of the approach with an 80 mW·cm-2 illumination threshold.

Conclusions:

• NaYF4:Nd3+ offers a promising solution for optical anti-counterfeiting.
• The developed UV luminescence technology is robust and effective in real-world, brightly lit environments.
• This approach enhances security verification against counterfeiting.