Interplay of defect levels and rare earth emission centers in multimode luminescent phosphors.

ABSTRACT: Multimode luminescence generally involves tunable photon emissions in response to various excitation or stimuli channels, which demonstrates high coding capacity and confidentiality abilities for anti-counterfeiting and encryption technologies. Integrating multimode luminescence into a single stable material is a promising strategy but remains a challenge. Here, we realize distinct long persistent luminescence, short-lived down/upconversion emissions in NaGdTi₂O₆:Pr³⁺, Er³⁺ phosphor by emloying interplay of defect levels and rare earth emission centers. The materials show intense colorful luminescence statically and dynamically, which responds to a wide spectrum ranging from X-ray to sunlight, thermal disturbance, and mechanical force, further allowing the emission colors manipulable in space and time dimensions. Experimental and theoretical approaches reveal that the Pr³⁺ ↔ Pr⁴⁺ valence change, oxygen vacancies and anti-site Ti_Gd defects in this disordered structure contributes to the multimode luminescence. We present a facile and nondestructive demo whose emission color and fade intensity can be controlled via external manipulation, indicating promise in high-capacity information encryption applications.

SUBMITTER: Zhou X 

PROVIDER: S-EPMC9732309 | biostudies-literature | 2022 Dec

REPOSITORIES: biostudies-literature