Novel strategy for designing photochromic ceramic: Reversible upconversion luminescence modification of the α-Ba2ScAlO5:Yb3+/Er3+ for optical information storage and multiple anti-counterfeiting

Reversible upconversion luminescence (RUCL) modification of rare earth ion-doped ceramic based on photochromism has received much attention in favor of expanding its practical applications. However, RUCL modification induced by photochromism usually employs these traditional methods (electric and magnetic fields) to induce bleaching, which limits its practical applications. In this work, a white α-Ba2ScAlO5: Yb3+/Er3+ (α-BSAO: Yb, Er) was prepared, which exhibits photochromic coloration from white to blue upon stimulation with 254 nm light. The coloration was able to be bleached by light (808 nm) and thermal (275 °C) stimulation, exhibiting reversible photochromism. The α-BSAO: Yb, Er ceramic exhibited good luminescence performance and reversibility under alternating cycles of 254 and 808 nm (or thermal) light stimulation. It suggests that α-BSAO: Yb, Er ceramic is an ideal anti-counterfeiting agent. The α-BSAO: Yb, Er ceramic sheets can be excited by ultraviolet and near-infrared light, and are capable of realizing the reading of optical information recorded on binary photochromic dot arrays. It shows the potential application prospects of α-Ba2ScAlO5: Yb3+/Er3+ ceramic in the field of optical storage and anti-counterfeiting.