Cyan emissive super-persistent luminescence and thermoluminescence in BaZrSi3O9:Eu2+,Pr3+ phosphors

Abstract

We developed a novel long-lasting phosphorescence (LLP) material BaZrSi₃O₉:Eu²⁺,Pr³⁺. The crystal structure, electronic structure and photoluminescence of this phosphor have been investigated systematically. The highlight of this work is the admirable LLP performances of BaZrSi₃O₉:Eu²⁺,Pr³⁺, which could be observed by the naked eye for 15 hours in the dark after ceasing the irradiation source. Moreover, we have analyzed the reason why the BaZrSi₃O₉:Eu²⁺,Pr³⁺ phosphor has such excellent persistent luminescence by exploring the distribution of traps in BaZrSi₃O₉:Eu²⁺,Pr³⁺ with the help of thermoluminescence (TL) spectra. A series of the excitation duration, decay duration and temperature dependent TL experiments of BaZrSi₃O₉:Eu²⁺,Pr³⁺ were conducted, revealing the trapping and detrapping of electrons into and from the shallow traps through the conduction band and the deeper traps via the tunnelling process. According to the experimental results, the mechanism of the feasible persistent luminescence of BaZrSi₃O₉:Eu²⁺,Pr³⁺ was also proposed and illustrated in detail.