Work

Be Aware of Impurity Phases: Red Emission in Europium‐Doped CaYGaO 4 Caused by Unintentionally Formed CaS:Eu 2+

Year: 2026

Type: article

Abstract: ABSTRACT Phosphors doped with divalent europium have attracted significant attention over the past decades due to the tuneable luminescence characteristics of the Eu 2+ center, making them highly attractive for lighting and display applications. However, achieving red emission based on divalent europium remains challenging. Here, we report the synthesis and characterization of the europium‐doped oxide CaYGaO 4 , which has previously been reported to exhibit a broad emission band centered at 650 nm that can be efficiently excited by blue light and was attributed to the 5d–4f transition of Eu 2+ . While Eu 3+ emission is readily obtained in this host lattice, achieving red Eu 2+ emission required the use of activated carbon rather than forming gas. Co‐doping with Dy 3+ enhances the long‐lasting afterglow. Based on detailed luminescence and structural characterization, the red emission at 650 nm was found to originate from an unintentionally formed CaS:Eu 2+ impurity phase, which could be traced back to the use of sulfur‐containing activated carbon during synthesis. This work highlights the importance of carefully checking for the formation of impurity phases in phosphor research, for instance, by using cathodoluminescence spectroscopy in a scanning electron microscope.

Source: Journal of the American Ceramic Society

DOI: 10.1111/jace.71295

Authors: Khadija Kaaroud, Henk Vrielinck, Jonas J. Joos, Philippe F. Smet

Institutions: Ghent University, Antwerp Maritime Academy

Language: English

Topic: Luminescence Properties of Advanced Materials

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: bronze

Funders: Universiteit Gent, Bijzonder Onderzoeksfonds UGent

Award: G9000957410