Modulating Trap Characteristics of Ca ₃ Ga ₄ O ₉ :Tb ³⁺ by Neighboring Co‐Doping Strategy for Optical Information Storage

Optically stimulated luminescence (OSL) materials offer significant potential for optical data storage (ODS) and anticounterfeiting applications. However, there are limited available OSL materials with deep traps, narrow trap distribution, and high trap density for such applications. Here, a neighboring co‐doping strategy is employed to tune persistent luminescence (PersL) and OSL properties of Ca 3 Ga 4 O 9 :Tb 3+ (CGOT) phosphor by Dy 3+ and Eu 3+ by modifying the trap depth, density, and distribution. Specifically, the effects of co‐doping on the crystal structure and unique characteristics of their trap depth, density, and distribution, along with PersL, thermally stimulated luminescence (TSL), and OSL properties have been analyzed. The observed strong bluish‐green PersL and OSL demonstrate varying intensity and decay profiles depending on the co‐dopant. The Ca 2.97 Ga 4 O 9 :0.5%Tb 3+ ,0.5%RE 3+ sample exhibits controllable photon release and adjustable shallow and deep trap depth, density, and distribution under both thermal and optical stimuli, leading to the formation of either shallow or deep traps with variable trap levels or eliminating them, ultimately improving their performance for ODS applications. This work highlights that trap modulation via neighboring co‐doping of RE ions is an effective approach to fine‐tune the PersL, TSL, and OSL properties of Ca 2.985‐x% Ga 4 O 9 :0.5%Tb 3+ ,x%RE 3+ for ODS and other potential applications.