Reversible Upconversion Luminescence Modification Based on Photochromism in BaMgSiO₄:Yb³⁺,Tb³⁺ Ceramics for Anti‐Counterfeiting Applications

Abstract Reversible upconversion luminescence modification based on photochromism has received considerable interest due to its potential applications in optical storage and high‐sensitivity optical switches. However, stimulation‐induced bleaching by an external thermal field is generally used for photochromism‐induced reversible upconversion luminescence modification, which limits its practical application. In this work, a gray BaMgSiO₄:Yb³⁺,Tb³⁺ ceramic is prepared, exhibiting the photochromism from gray to pink color when stimulated by 254 nm light. Interestingly, the pink BaMgSiO₄:Yb³⁺,Tb³⁺ ceramic can be bleached by either a 473 nm laser or thermal stimulation. The reversible change between gray and pink color exhibits excellent reproducibility over several cycles by alternating between 254 and 473 nm (or thermal) light stimulation. The influence of the reversible photochromism of the BaMgSiO₄:Yb³⁺,Tb³⁺ ceramic on its upconversion luminescence is investigated. Reversible modification of the upconversion luminescence is demonstrated by alternating between 254 and 473 nm (or thermal) light stimulation. For reversible modulation of the upconversion luminescence, excellent reproducibility is realized after several cycles. As an example, the application of the BaMgSiO₄:Yb³⁺,Tb³⁺ photochromic ceramic as an anti‐counterfeiting agent is described.