Reversible Regulation Of Luminescence Properties Of Photoactive Ion-doped BaMgSiO₄ Luminescent Materials Based On Photochromic Effect

Luminescent materials are widely used in our daily life,such as LED lighting,plasma display,traffic signal indication,safety warning signs,etc.The regulation of emission property of luminescent materials can further expand their applications.In the existing research,the luminescence can be controlled by the photonic bandgap structure,but the control of the luminescence is difficult and irreversible.With the help of different external field stimuli such as light field and thermal field,the reversible control of light emission can be realized,and it has great applications in the fields of optical switch,optical storage,and anti-counterfeiting.Therefore,in this work,the light/heat-induced inorganic material BaMgSiO₄ matrix reversible color is used to modify its luminescence properties,and its potential applications in optical storage and anti-counterfeiting are further explored.The photochromism and luminescence property of Bi³⁺doped BaMgSiO₄(BMS-Bi³⁺)ceramics have been studied.The ceramic has a reversible photochromic effect:the ceramic’s body color deepens and the emission intensity weakens under the stimulation of 254nm UV light;while the body color recovered and the emission intensity enhanced under the irradiation 532nm visible light.It is confirmed that it has reversible photochromic-photobleaching characteristics,and the luminescence characteristics of Bi³⁺are modified based on the process.Further,based on the reversible control of emission intensity by the photochromic reaction,two light sources were used to repeatedly make different shapes of patterns on the surface of the ceramic.Demonstrating the feasibility of reversible writing-erasing and reading-out of the optical information in the exploring field of optical storage.The photochromic effect and luminescence property of Yb³⁺and Tb³⁺doped BaMgSiO₄（BMS-YbTb）ceramics were studied.Under UV light irradiation,the color of the ceramic changed from light gray to pink,and the up-conversion luminescence（UCL）weakened.While it can be bleached by thermal field,473nm or532nm laser stimulation,and the emission intensity enhanced when the color faded.It is confirmed that BMS-YbTb has the reversible coloration-bleaching characteristics,and the UCL was modified in the process.Fe-doping greatly improved the photochromic performance,the potential application of smartphone anti-safe based on photochromism was explored.Paramagnetic Resonance（EPR）,Thermoluminescence（TL）and other methods were used to analyze the photochromic mechanism.The coloration-bleaching process corresponds to the capturing-releasing of charge carriers,in which oxygen vacancy plays an important role.Combined with the result of decay curve,the mechanism of reversible PL modification was explored.