Designing LiTaO₃:Ln³⁺,Eu³⁺ (Ln = Tb or Pr) perovskite dosimeter with excellent charge carrier storage capacity and stability for anti-counterfeiting and flexible X-ray imaging

Abstract

Developing X-ray charged dosimeters with excellent charge carrier storage capacity and stability is challenging. Such energy storage dosimeters have fascinating use in developing novel applications, for instance, in radiation detection, advanced multimode anti-counterfeiting, and flexible X-ray imaging of curved objects. Herein, novel LiTaO₃:Ln³⁺,Eu³⁺ (Ln = Tb or Pr) perovskite dosimeters are reported by combining the vacuum referred binding energy (VRBE) diagram of LiTaO₃ and the optimization of dopant's concentration and compound synthesis condition. Based on the VRBE diagram prediction, charge carrier capturing and de-trapping processes in Eu³⁺ and/or Ln³⁺ (Ln = Tb or Pr) doped LiTaO₃ will be studied to unravel the role of Eu³⁺ as a good electron trapping centre and to discover a record storage phosphor. The ratios of the thermoluminescence intensity of the optimized LiTaO₃:0.005Tb³⁺,0.001Eu³⁺ to that of the state-of-the-art BaFBr(I):Eu²⁺, Al₂O₃:C, or NaLuF₄:Tb³⁺ are 5.2, 8.8, or 2.8, respectively. The charge carriers can be stored more than 1000 h in LiTaO₃:0.005Tb³⁺,0.001Eu³⁺. Proof-of-concept anti-counterfeiting application will be demonstrated by combining the colour-tailorable photoluminescence, afterglow, thermally, or optically stimulated luminescence in LiTaO₃:0.005Tb³⁺,xEu³⁺ and LiTaO₃:0.005Pr³⁺,0.001Eu³⁺. Multimode anti-counterfeiting application will be proposed by combining a high absolute X-ray scintillation light yield of 19000 ± 1800 ph/MeV of LiTaO₃:0.005Tb³⁺,0.001Eu³⁺. Proof-of-concept flexible X-ray imaging application will be demonstrated by using the optimized LiTaO₃:0.005Tb³⁺, 0.001Eu³⁺ dispersed in a silicone gel film.