VRBE and HRBE schemes of lanthanides: design of dual-luminescence-center long persistent luminescence phosphors with Pr3+ or/and Tb3+ doping in Mg3Y2Ge3O12 garnet with high storage capacity for anti-counterfeiting, information storage, and X-ray imaging

Abstract

The development of X-ray charged long persistent luminescence (LPL) phosphors with excellent storage capacity remains a significant challenge. These phosphors have multifunctional applications in white light-emitting diodes (w-LEDs), multi-mode anti-counterfeiting, information storage, and X-ray imaging. Herein, by combining the refined chemical shift model, optical spectroscopy, and thermoluminescence (TL) curves, the host-referred and vacuum-referred binding energy (HRBE and VRBE) schemes about Mg₃Y₂Ge₃O₁₂:Ln³⁺(MYGO:Ln, Ln = Pr or/and Tb) phosphors are constructed and validated. MYGO:Pr,Tb avoids the re-absorption issue in the blue light region and agrees well with blue phosphors for w-LED applications. MYGO:Pr,Tb Charged with X-rays (Xc), the TL intensity ratios to commercial SrAl₂O₄:Eu²⁺,Dy³⁺/BaFBr(I):Eu²⁺ are 1.517 and 1.435, respectively, and 50% of the carriers remain for over 1000 h. Finally, the MYGO series phosphors are successfully applied in multi-mode anti-counterfeiting, information storage, and X-ray imaging.