Sol–Gel Synthesis of Translucent and Persistent Luminescent SiO2@ SrAl2O4 Eu, Dy, B Materials

Abstract

This publication offers an economically promising method of persistent luminescent silicate glass synthesis that does not involve high temperatures or ready-made (separately synthesized) PeL particles. In this study, we demonstrate the formation of SrAl2O4 doped with Eu, Dy, and B in a SiO2 glass structure using the one-pot low-temperature sol–gel synthesis method. By varying the synthesis conditions, we can use water-soluble precursors (e.g., nitrates) and a dilute aqueous solution of rare-earth (RE) nitrates as starting materials for SrAl2O4 synthesis, which can be formed during the sol–gel process at relatively low sintering temperatures (600 °C). As a result, translucent, persistently luminescent glass is obtained. The glass shows the typical Eu2+ luminescence and the characteristic afterglow. The afterglow duration is about 20 s. It is concluded that the slow drying procedure (2 weeks) is optimal for these samples to sufficiently get rid of the excess water (mainlyOH groups) and solvent molecules that can influence the strontium aluminate luminescence properties and have a pernicious effect on the afterglow. It can also be concluded that boron is playing a crucial role in the formation of trapping centers needed for PeL processes in the PeL silicate glass.

Solvothermal Treatment of Micron-Sized Commercial SrAl2O4:Eu2+, Dy3+ Phosphors and One-Step Preparation of Nanophosphors for Fingerprint Imaging

“…SrAl 2 O 4 :Eu 2+ , Dy 3+ is a representative of inorganic long afterglow luminescent materials, first synthesized by Matsuzawa in 1996, which has several outstanding advantages: stability, high efficiency, and less toxicity [31]. However, the current production process of commercial SrAl 2 O 4 :Eu 2+ , Dy 3+ is based on solid-phase reaction [32][33][34][35][36][37], which leads to poor homogeneity and product grain size in the micrometer range, thus limiting the practical application of SrAl 2 O 4 :Eu 2+ , Dy 3+ phosphors in fields such as bioimaging, biomedicine, and fine chemicals. However, with the advancement of industrial and medical technologies, there is an urgent need for nanophosphors with good optical properties, uniform particles, and controllable morphology [17,38].…”