Insight into Luminescence Properties of Robust BaSi₃Al₃O₄N₅:Ce³⁺ Blue Persistent Phosphors for Optical Information Storage

The commercial blue persistent luminescent (PersL) phosphor (CaAl₂O₄:Eu²⁺,Nd³⁺) is renowned for its exceptional PersL duration, but it is hampered by its poor chemical stability. There is an urgent need to develop blue PersL phosphors that can combine the excellent PersL property with robust stability. In this work, we report on a series of highly stable Ce³⁺-doped oxynitride PersL phosphors. Notably, BaSi₃Al₃O₄N₅:Ce³⁺ has been identified to contain two distinct types of defects in the host: one associated with photoluminescence (PL) and the other with electron trapping and detrapping dynamics. These intrinsic defects have been systematically investigated and confirmed by analyzing both PL and PersL spectra, which could be generated by nitrogen deficiency and the existing oxygen vacancy in BaSi₃Al₃O₄N₅. BaSi₃Al₃O₄N₅:Ce³⁺ has a widely distributed trap from 0.21 to 1.02 eV, with a peak at 0.63 eV, as determined by the initial rise method. BaSi₃Al₃O₄N₅:Ce³⁺ exhibits not only excellent water-resistance stability but also superior heat-resistant stability. Leveraging its widely distributed traps and great chemical stability, we have successfully demonstrated the optical information storage ability of BaSi₃Al₃O₄N₅:Ce³⁺ by using a gradual optical writing method. This comprehensive study provides valuable insights into the development of stable oxynitride PersL phosphors for potential applications in optoelectronic devices.