Mn2+/Pr3+/Tb3+ single-doped Mg4Ga4Ge3O16 persistent luminescence materials for optical information storage application

Persistent luminescence (PersL) phosphors are considered as promising candidates for the next generation of information storage medium. Mg₄Ga₄Ge₃O₁₆ (MGG) is an electron trapping material which exhibits defect luminescence, and the luminescent properties are easily tuned via doping various activated ions. In this work, undoped and Mn²⁺/Pr³⁺/Tb³⁺ single-doped MGG phosphors were synthesized via high temperature solid phase reactions. X-ray diffraction and scanning electron microscope results confirm that the activated ions tend to occupy Mg²⁺ sites. Excited at 265 nm, the MGG host exhibits a defect emission band peaked at 450 nm. Red, pink and green emissions are observed in the Mn²⁺/Pr³⁺/Tb³⁺ single-doped MGG samples, which are ascribed to the Mn²⁺: ⁴T₁(G) → ⁶A₁(S), Pr³⁺: ¹D₂ → ³H₄ and Tb³⁺: ⁵D₄ → ⁷F₅ transitions, respectively. All the samples exhibit bright PersL for minutes after the cessation of excitation. The energy transfer, concentration quenching, luminescence decay and afterglow mechanisms are also discussed in detail. The phosphors exhibit efficient thermal and optical stimuli response, showing great potentials in the optical information storage.