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

Abstract

Multimodal luminescent materials displaying dynamically tunable multicolor emissions under diverse excitation channels are at the core of optical information encryption technologies. However, simultaneous achievement of high-performance multimodal luminescence with anti-thermal quenching (ATQ) feature remains a critical challenge. Herein, a new class of SrZnP₂O₇:RE (RE = Sm³⁺, Dy³⁺, Tb³⁺, Tm³⁺) phosphors is developed to fulfill these requirements through precise defect engineering. These phosphors exhibit photoluminescence (PL), radioluminescence (RL), mechanoluminescence (ML), thermoluminescence (TL), and persistent luminescence (PersL) with emission spanning 350-750 nm. By strategically incorporating charge compensators (Li⁺, Na⁺, K⁺), precise regulation of trap distribution and density is demonstrated, yielding remarkable enhancements in PL, quantum efficiency, RL intensity, and X-ray afterglow duration. Crucially, the engineered deep traps in Sm/Dy/Tm-doped systems enable exceptional ATQ behavior. Comprehensive investigations reveal the critical role of charge compensation and defect redistribution in modulating luminescence performance. Benefiting from their superior multimodal emission properties, these phosphors demonstrate great promise for X-ray imaging and high-security anti-counterfeiting/encryption applications. This work establishes a new paradigm in luminescent material design, providing both fundamental insights into defect-luminescence property relationships and a practical framework for constructing advanced optical materials with tailored multimodal responses through precision trap state engineering.