Preparation and optical properties of Eu2+–Pr3+/Nd3+ co-doped CaAl2O4 long afterglow luminescent materials

Abstract

A long afterglow material CaAl₂O₄:Eu²⁺,Pr³⁺ emitting blue light has been synthesized by a high-temperature solid-phase method. The effect of a series of preparation conditions on CaAl₂O₄:Eu²⁺,Pr³⁺ was first investigated using a single-factor preference method, and the optimal synthesis conditions were then obtained through orthogonal tests. The target products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), elemental mapping, fluorescence spectroscopy, and afterglow properties. The XRD results indicate the successful synthesis of CaAl₂O₄:Eu²⁺,Pr³⁺ materials, which was further verified by XPS analysis. The afterglow properties of the target products were further improved by doping with Nd³⁺ under optimum conditions obtained from orthogonal tests. The improvement was analyzed through XRD, fluorescence, afterglow and thermoluminescence analysis. The results indicate that doping with Nd³⁺ in CaAl₂O₄:Eu²⁺,Pr³⁺ materials significantly enhanced the afterglow properties, including an initial brightness of 2318 mcd m⁻² and a duration of 26.5 hours. Thanks to its excellent blue long afterglow luminescence, the material is anticipated to have applications in energy-efficient lighting systems and solar energy systems.